{"msg":"计算机系统基础","code":200,"data":{"currentIndex":null,"examId":null,"examTime":null,"questionList":[{"id":"794930105288773633","title":"<p>如果主存容量为16M字节，且按字节编址，表示该主存地址至少应需要（ ）位。</p>","analyze":"<p>用二进制编码表示地址，16M=2^24，因此最少需要24位。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930107201376257"],"itemList":[{"id":"794930107163627521","questionId":"794930105288773633","content":"16","answer":0,"chooseValue":"A"},{"id":"794930107180404737","questionId":"794930105288773633","content":"20","answer":0,"chooseValue":"B"},{"id":"794930107201376257","questionId":"794930105288773633","content":"24","answer":1,"chooseValue":"C"},{"id":"794930107222347777","questionId":"794930105288773633","content":"32","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930054302814209","title":"<p>以下关于串行总线的说法中，正确的是（ ）。</p>","analyze":"<p>关于串行总线的特点如下。</p><p>（1） 串行总线有半双工、全双工之分，全双工是一条线发一条线收。</p><p>（2） 串行总线适宜长距离传输数据。</p><p>（3） 串行总线按位（bit）发送和接收，尽管较按字节（byte）的并行通信慢，但是串口可以在使用一条线发送数据的同时用另一条线接收数据。它很简单并且能够实现远距离通信，如IEEE488定义并行通行状态时，规定设备线总长不得超过20米，并且任意两种设备间的长度不得超过2米。而对于串口而言，长度可达1200米。</p><p>（4） 串口通信最重要的参数是波特率、数据位、停止位和奇偶校验，对于两个进行通行的端口，这些参数必须匹配。</p><p>（5） 串行总线的数据发送和接收可以使用多种方式，中断方式与DMA都较为常见。</p><p>选项A不正确的原因是串行总线存在全双工、半双工两种方式；选项B不正确的原因是串行总线可随时调整波特率；选项D不正确的原因是串行总线的数据发送和接收可以使用查询和中断两种。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930056546766849"],"itemList":[{"id":"794930056504823809","questionId":"794930054302814209","content":"串行总线一般都是全双工总线，适宜于长距离传输数据","answer":0,"chooseValue":"A"},{"id":"794930056521601025","questionId":"794930054302814209","content":"串行总线传输的波特率是总线初始化时预先定义好的，使用中不可改变","answer":0,"chooseValue":"B"},{"id":"794930056546766849","questionId":"794930054302814209","content":"串行总线是按位（bit）传输数据的，其数据的正确性依赖于校验码纠正","answer":1,"chooseValue":"C"},{"id":"794930056571932673","questionId":"794930054302814209","content":"串行总线的数据发送和接收是以软件查询方式工作","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929981472919553","title":"<p><span style=\"font-family:宋体\">评价计算机系统性能的方法主要有三种，不包括</span><span style=\"font-family: Calibri; font-size: 12pt;\">___</span><span style=\"font-family:宋体\">。</span></p><p class=\"p\"><br/></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">计算机系统的性能评价方法主要有三种，分别是测量方法、分析方法和模拟方法。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">测量方法主要是通过采用各种性能数据获取方法和运行各种不同类型的基准测试程序或工具来测量目标系统的性能情况。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">分析方法通过为计算机系统建立一种数学模型，进而在给定输入条件下通过计算来获取目标系统的性能情况。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">模拟方法通过构造系统模型和工作负载模型来近似模仿目标系统，以了解系统的特性。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">计算机系统的性能指标是一些精度较高的数据，用户调查问卷或专家小组法只能取得一些大致的、轮廓性的数据。多数用户并没有使用多种计算机系统，难以进行比较，所以计算机系统性能指标的评价一般不通过用户调查法来确定。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">答案</span></span></strong><span style=\"font-family: Calibri; font-size: 12pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929983691706369"],"itemList":[{"id":"794929983645569025","questionId":"794929981472919553","content":"测量方法","answer":0,"chooseValue":"A"},{"id":"794929983662346241","questionId":"794929981472919553","content":"分析方法","answer":0,"chooseValue":"B"},{"id":"794929983679123457","questionId":"794929981472919553","content":"模拟方法","answer":0,"chooseValue":"C"},{"id":"794929983691706369","questionId":"794929981472919553","content":"用户调查方法","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930256686370817","title":"<p>由于处理器芯片在不同领域应用时，需要考虑对环境的适应性。通常，我们把芯片分为民用级、工业级、车载级和军工级。 （14） 是工业级芯片的标准工作温度范围。</p>","analyze":"<p>芯片可以使用的环境温度划分如下：军工级(-55℃~+150℃)，车载级(-40℃~+125℃)，工业级(-40℃~+85℃)，民用级(0℃~+70℃)。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930258594779137"],"itemList":[{"id":"794930258531864577","questionId":"794930256686370817","content":"-55℃～+150℃","answer":0,"chooseValue":"A"},{"id":"794930258561224705","questionId":"794930256686370817","content":"-40℃～+125℃","answer":0,"chooseValue":"B"},{"id":"794930258594779137","questionId":"794930256686370817","content":"-40℃～+85℃","answer":1,"chooseValue":"C"},{"id":"794930258624139265","questionId":"794930256686370817","content":"0℃～+70℃","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929990566170625","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机采用分级存储体系的主要目的是为了解决</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">的问题。</span></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">为了解决对存储器要求容量大、速度快、成本低三者之间的矛盾，目前通常采用多级存储器体系结构，即使用高速缓冲存储器、主存储器和外存储器。高速缓冲存储器：高速存取指令和数据，存取速度快，但存储容量小。主存储器：主存存放计算机运行期间的大量程序和数据，存取速度较快，存储容量不大。外存储器：外存存放系统程序和大型数据文件及数据库，存储容量大，成本低。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929992457801729"],"itemList":[{"id":"794929992420052993","questionId":"794929990566170625","content":"主存容量不足","answer":0,"chooseValue":"A"},{"id":"794929992432635905","questionId":"794929990566170625","content":"存储器读写可靠性","answer":0,"chooseValue":"B"},{"id":"794929992445218817","questionId":"794929990566170625","content":"外设访问效率","answer":0,"chooseValue":"C"},{"id":"794929992457801729","questionId":"794929990566170625","content":"存储容量、成本和速度之间的矛盾","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930231185002497","title":"<p>使用200dpi的扫描分辨率扫描一幅2×2.5英寸的黑白图像，可以得到一幅（）像素的图像。</p>","analyze":"<p> 在用扫描仪扫描图像时，通常要指定图像的分辨率，用每英寸多少点(dots per inch dpi)表示。用200dpi的扫描分辨率扫描一幅2×2.5英寸的黑白图像，就得到一幅400×500个像素的图像。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930233072439297"],"itemList":[{"id":"794930233034690561","questionId":"794930231185002497","content":"200×2","answer":0,"chooseValue":"A"},{"id":"794930233051467777","questionId":"794930231185002497","content":"2×2.5","answer":0,"chooseValue":"B"},{"id":"794930233072439297","questionId":"794930231185002497","content":"400×500","answer":1,"chooseValue":"C"},{"id":"794930233093410817","questionId":"794930231185002497","content":"800×1000","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930270024257537","title":"（ ）是专用于实时的数字信号处理的处理器。","analyze":"DSP是专用于实时的数字信号处理，常采用哈佛体系结构。","multi":0,"questionType":1,"answer":"A","chooseItem":["794930271878139905"],"itemList":[{"id":"794930271878139905","questionId":"794930270024257537","content":"DSP","answer":1,"chooseValue":"A"},{"id":"794930271890722817","questionId":"794930270024257537","content":"CUP","answer":0,"chooseValue":"B"},{"id":"794930271903305729","questionId":"794930270024257537","content":"GPU","answer":0,"chooseValue":"C"},{"id":"794930271920082945","questionId":"794930270024257537","content":"FPGA","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930051131920385","title":"目前处理器市场中存在CPU和DSP两种类型处理器，分别用于不同场景。这两种处理器具有不同的体系结构，DSP采用（ ）。","analyze":"<p>编程DSP芯片是一种具有特殊结构的微处理器，为了达到快速数字信号处理的目的，DSP芯片一般都采用特殊的软硬件结构。</p><p>（1） 哈佛结构。</p><p>DSP采用哈佛结构，将存储器空间划分成两个，分别存储程序和数据。它们有两组总线连接到处理器核，允许同时对它们进行访问。每个存储器独立编址，独立访问。这种安排将处理器的数据吞吐率加倍，更重要的是同时为处理器核提供数据与指令。在这种布局下，DSP得以实现单周期的MAC指令。</p><p>在哈佛结构中，由于程序和数据存储器在两个分开的空间中，因此取指和执行能完全重叠运行。</p><p>（2） 流水线。</p><p>与哈佛结构相关，DSP芯片广泛采用2～6级流水线以减少指令执行时间，从而增强了处理器的处理能力。这可使指令执行能完全重叠，每个指令周期内，不同的指令都处于激活状态。</p><p>（3） 独立的硬件乘法器。</p><p>在实现多媒体功能及数字信号处理的系统中，算法的实现和数字滤波都是计算密集型的应用。在这些场合，乘法运算是数字处理的重要组部分，是各种算法实现的基本元素之一。乘法的执行速度越快，DSP处理器的性能越高。相比一般的处理器需要30～40个指令周期，DSP芯片的特征就是有一个专用的硬件乘法器，乘法可以在一个周期内完成。</p><p>（4） 特殊的DSP指令。</p><p>DSP的另一特征是采用特殊的指令，专为优化数字信号处理中的一些常用算法。这些特殊指令为一些典型的数字处理提供加速，可以大幅提高处理器的执行效率，使一些高速系统的实时数据处理成为可能。</p><p>（5） 独立的DMA总线和控制器。</p><p>有一组或多组独立的DMA总线，与CPU的程序、数据总线并行工作。在不影响CPU工作的条件下，DMA的速度可以达到800 MB/s以上。这在需要大数据量进行交换的场合可以减小CPU的开销，提高数据的吞吐率，提高系统的并行执行能力。</p><p>（6） 多处理器接口。</p><p>使多个处理器可以很方便地并行或串行工作以提高处理速度。</p><p>（7） JTAG（Joint Test Action Group）标准测试接口（IEEE 1149标准接口）。</p><p>便于对DSP进行片上的在线仿真和多DSP条件下的调试。</p><p>（8） 快速的指令周期。</p><p>哈佛结构、流水线操作、专用的硬件乘法器、特殊的DSP指令再加上集成电路的优化设计，可使DSP芯片的指令周期降低至10 ns以下，快速的指令周期可以使DSP芯片能够实时实现许多DSP应用。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930053128409089"],"itemList":[{"id":"794930053073883137","questionId":"794930051131920385","content":"冯.诺伊曼结构","answer":0,"chooseValue":"A"},{"id":"794930053128409089","questionId":"794930051131920385","content":"哈佛结构","answer":1,"chooseValue":"B"},{"id":"794930053170352129","questionId":"794930051131920385","content":"FPGA结构","answer":0,"chooseValue":"C"},{"id":"794930053208100865","questionId":"794930051131920385","content":"与CPU相同结构","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930179997716481","title":"<p>以下关于中断方式与DMA方式的叙述中，正确的是（）</p>","analyze":"<p>中断方式与DMA方式都可实现外设与CPU之间的并行工作。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930181927096321"],"itemList":[{"id":"794930181927096321","questionId":"794930179997716481","content":"中断方式与DMA方式都可实现外设与CPU之间的并行工作","answer":1,"chooseValue":"A"},{"id":"794930181948067841","questionId":"794930179997716481","content":"程序中断方式和DMA方式在数据传输过程中都不需要CPU的干预","answer":0,"chooseValue":"B"},{"id":"794930181969039361","questionId":"794930179997716481","content":"采用DMA方式传输数据的速度比程序中断方式的速度慢","answer":0,"chooseValue":"C"},{"id":"794930181994205185","questionId":"794930179997716481","content":"程序中断方式和DMA方式都不需要CPU保护现场","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929913978179585","title":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MPEG-1视频编码标准中定义了</span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>62）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">种不同类型的视频帧</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">试题解析：</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MPEG-1标准中，视频图像的帧序列包括帧内图像(I帧)、预测图像(P帧</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">和插补图像</span>(B帧</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">，或称双向预测图像</span>3种。帧内图像不参照任何过去的或者将来的其他图像帧，压缩编码直接采用类JPEG的压缩算法，故其可以直接作为索引和访问点；预测图像使用基于运动补偿的单向帧间预测编码；而插补图像则使用双向帧间预测编码。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">62）</span><span style=\"font-family: 宋体; font-size: 10.5pt;\">B</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> </span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929915874004993"],"itemList":[{"id":"794929915857227777","questionId":"794929913978179585","content":"2","answer":0,"chooseValue":"A"},{"id":"794929915874004993","questionId":"794929913978179585","content":"3","answer":1,"chooseValue":"B"},{"id":"794929915886587905","questionId":"794929913978179585","content":"4","answer":0,"chooseValue":"C"},{"id":"794929915903365121","questionId":"794929913978179585","content":"5","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930086263410689","title":"在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式（包括无条件传送与程序查询方式）、程序中断方式、DMA工作方式、通道方式、I/O处理机。（）方式I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，并且只适用于简单的I/O控制。（）允许主存储器和I/O设备之间通过某种控制器直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。 （）在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入。（）指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。上述工作方式中，（请作答此空）工作方式CPU与I/O设备是串行工作的。","analyze":"<p>在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式、程序中断方式、DMA工作方式、通道方式、I/O处理机。</p><p>1、程序控制方式</p><p>分为无条件查询和程序查询方式。</p><p> ① 无条件传送方式，I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，而cpu在需要时，随时直接利用I/O指令访问相应的I/O端口，实现与外设的数据交换。优点是软、硬件结构简单，缺点是对时序要求高，只适用于简单的I/O控制。</p><p>② 程序查询方式</p><p>程序查询方式也称为程序轮询方式，该方式采用用户程序直接控制主机与外部设备之间输入/输出操作。CPU必须不停地循环测试I/O设备的状态端口，当发现设备处于准备好(Ready)状态时，CPU就可以与I/O设备进行数据存取操作。这种方式下的CPU与I/O设备是串行工作的。</p><p>2、中断方式</p><p>当I/O设备结束(完成、特殊或异常)时，就会向CPU发出中断请求信号，CPU收到信号就可以采取相应措施。当某个进程要启动某个设备时，CPU就向相应的设备控制器发出一条设备I/O启动指令，然后CPU又返回做原来的工作。CPU与I/O设备可以并行工作，与程序查询方式相比，大大提高了CPU的利用率。</p><p>3、DMA(直接内存存取)方式</p><p>DMA方式也称为直接主存存取方式，其思想是：允许主存储器和I/O设备之间通过“DMA控制器(DMAC)”直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。</p><p>4、通道控制方式</p><p>在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入，使主机和外设并行工作程度更高。</p><p>5、I/O处理机</p><p>指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930088188596225"],"itemList":[{"id":"794930088121487361","questionId":"794930086263410689","content":"中断方式","answer":0,"chooseValue":"A"},{"id":"794930088142458881","questionId":"794930086263410689","content":"DMA方式","answer":0,"chooseValue":"B"},{"id":"794930088163430401","questionId":"794930086263410689","content":"无条件传送","answer":0,"chooseValue":"C"},{"id":"794930088188596225","questionId":"794930086263410689","content":"程序查询","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930030479167489","title":"<p><span style=\"font-family: Calibri; font-size: 12pt;\">Blu-ray</span><span style=\"font-family:宋体\">光盘使用蓝色激光技术实现数据存取，其单层数据容量达到了（ </span><span style=\"font-family:Calibri\"> </span><span style=\"font-family:宋体\">）。</span></p><p class=\"p\"><br/></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">蓝光（</span>Blu-ray<span style=\"font-family:宋体\">）或称蓝光盘（</span><span style=\"font-family:Calibri\">Blu-ray Disc</span><span style=\"font-family:宋体\">，缩写为</span><span style=\"font-family:Calibri\">BD</span><span style=\"font-family:宋体\">）利用波长较短（</span><span style=\"font-family:Calibri\">405nm</span><span style=\"font-family:宋体\">）的蓝色激光读取和写入数据，并因此而得名。而传统</span><span style=\"font-family:Calibri\">DVD</span><span style=\"font-family:宋体\">需要光头发出红色激光（波长为</span><span style=\"font-family:Calibri\">650nm </span><span style=\"font-family:宋体\">）来读取或写入数据，通常来说波长越短的激光，能够在单位面积上记录或读取更多的信息。因此，蓝光极大地提高了光盘的存储容量，对于光存储产品来说，蓝光提供了一个跳跃式发展的机会。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"><br/></span><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">目前为止，蓝光是最先进的大容量光碟格式，</span>BD<span style=\"font-family:宋体\">激光技术的巨大进步，使你能够在一张单碟上存储</span><span style=\"font-family:Calibri\">25GB</span><span style=\"font-family:宋体\">的文档文件。这是现有（单碟）</span><span style=\"font-family:Calibri\">DVDs</span><span style=\"font-family:宋体\">的</span><span style=\"font-family:Calibri\">5</span><span style=\"font-family:宋体\">倍。在速度上，蓝光允许</span><span style=\"font-family:Calibri\">1~2</span><span style=\"font-family:宋体\">倍或者说每秒</span><span style=\"font-family:Calibri\">4.5~9</span><span style=\"font-family:宋体\">兆字节的记录速度。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">试题答案</span></span></strong><span style=\"font-family: 宋体; font-size: 12pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930032391770113"],"itemList":[{"id":"794930032337244161","questionId":"794930030479167489","content":"4.7GB","answer":0,"chooseValue":"A"},{"id":"794930032354021377","questionId":"794930030479167489","content":"15GB","answer":0,"chooseValue":"B"},{"id":"794930032370798593","questionId":"794930030479167489","content":"17GB","answer":0,"chooseValue":"C"},{"id":"794930032391770113","questionId":"794930030479167489","content":"25GB","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930077757362177","title":"在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式（包括无条件传送与程序查询方式）、程序中断方式、DMA工作方式、通道方式、I/O处理机。（）方式I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，并且只适用于简单的I/O控制。（请作答此空）允许主存储器和I/O设备之间通过某种控制器直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。 （ ）在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入。（ ）指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。上述工作方式中，（ ）工作方式CPU与I/O设备是串行工作的。","analyze":"<p>在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式、程序中断方式、DMA工作方式、通道方式、I/O处理机。</p><p>1、程序控制方式</p><p>分为无条件查询和程序查询方式。</p><p> ① 无条件传送方式，I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，而cpu在需要时，随时直接利用I/O指令访问相应的I/O端口，实现与外设的数据交换。优点是软、硬件结构简单，缺点是对时序要求高，只适用于简单的I/O控制。</p><p>② 程序查询方式</p><p>程序查询方式也称为程序轮询方式，该方式采用用户程序直接控制主机与外部设备之间输入/输出操作。CPU必须不停地循环测试I/O设备的状态端口，当发现设备处于准备好(Ready)状态时，CPU就可以与I/O设备进行数据存取操作。这种方式下的CPU与I/O设备是串行工作的。</p><p>2、中断方式</p><p>当I/O设备结束(完成、特殊或异常)时，就会向CPU发出中断请求信号，CPU收到信号就可以采取相应措施。当某个进程要启动某个设备时，CPU就向相应的设备控制器发出一条设备I/O启动指令，然后CPU又返回做原来的工作。CPU与I/O设备可以并行工作，与程序查询方式相比，大大提高了CPU的利用率。</p><p>3、DMA(直接内存存取)方式</p><p>DMA方式也称为直接主存存取方式，其思想是：允许主存储器和I/O设备之间通过“DMA控制器(DMAC)”直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。</p><p>4、通道控制方式</p><p>在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入，使主机和外设并行工作程度更高。</p><p>5、I/O处理机</p><p>指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930079653187585"],"itemList":[{"id":"794930079636410369","questionId":"794930077757362177","content":"I/O处理机","answer":0,"chooseValue":"A"},{"id":"794930079653187585","questionId":"794930077757362177","content":"DMA方式","answer":1,"chooseValue":"B"},{"id":"794930079665770497","questionId":"794930077757362177","content":"通道控制方式","answer":0,"chooseValue":"C"},{"id":"794930079682547713","questionId":"794930077757362177","content":"无条件传送","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930060594270209","title":"<p>若信息码字为111000110，生成多项式G(X)=x^5+x^3+x+1，则计算出的CRC校验码为（ ）。</p>","analyze":"<p><br/></p><p><br/></p><p>多项式为101011，信息码右边补5个0后与多项式做模二除法（即11100011000000 ? 101011），得余数即可。模2除法与算术除法类似，但每一位除的结果不影响其他位即不向上一位借位，所以实际上就是异或（相同为0，不同为1）。</p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/7d0453170d0ba06e8e2086b9f1895fe6.jpg?x-oss-process=style/ruankaodaren\" title=\"7d0453170d0ba06e8e2086b9f1895fe6.jpg\" alt=\"1.jpg\"/>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930062456541185"],"itemList":[{"id":"794930062443958273","questionId":"794930060594270209","content":"01101","answer":0,"chooseValue":"A"},{"id":"794930062456541185","questionId":"794930060594270209","content":"11001","answer":1,"chooseValue":"B"},{"id":"794930062469124097","questionId":"794930060594270209","content":"001101","answer":0,"chooseValue":"C"},{"id":"794930062485901313","questionId":"794930060594270209","content":"011001","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930004893913089","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">以下媒体中</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">是表示媒体。</span></span></p>","analyze":"<p><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 20.7pt;\">表示媒体是为了加工、处理和传输感觉媒体而人为研究、构造出来的一种媒体，它有各种编码方式，如：文本编码、图像编码和声音编码等。</span><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930006726823937"],"itemList":[{"id":"794930006705852417","questionId":"794930004893913089","content":"声音","answer":0,"chooseValue":"A"},{"id":"794930006726823937","questionId":"794930004893913089","content":"声音编码","answer":1,"chooseValue":"B"},{"id":"794930006743601153","questionId":"794930004893913089","content":"超声波","answer":0,"chooseValue":"C"},{"id":"794930006760378369","questionId":"794930004893913089","content":"喇叭","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930219877158913","title":"<p>现有4级指令流水线，分别完成取指、取数、运算、传送结果4步操作。若完成上述操作的时间依次为9ns，10ns，6ns和8ns，则流水线的操作周期应设计为（）ns。</p>","analyze":"<p>由流水线技术的基本特征可知，其平均时间取决于流水线中最慢的操作，所以流水线的操作周期应设计为时间最长的步骤的时间。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930221785567233"],"itemList":[{"id":"794930221731041281","questionId":"794930219877158913","content":"6","answer":0,"chooseValue":"A"},{"id":"794930221747818497","questionId":"794930219877158913","content":"8","answer":0,"chooseValue":"B"},{"id":"794930221768790017","questionId":"794930219877158913","content":"9","answer":0,"chooseValue":"C"},{"id":"794930221785567233","questionId":"794930219877158913","content":"10","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930168371105793","title":"利用海明码（Hamming Code）纠正单位错，如果有6 位信息位，则需要加入（14）位冗余位。","analyze":"<p>校验码通过添加冗余信息来进行数据的校验。其中海明码的信息位和冗余位满足如下关系：</p><p>2^k≥n+k+1</p><p>其中n表示信息位，k表示冗余位。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930170271125505"],"itemList":[{"id":"794930170229182465","questionId":"794930168371105793","content":"2","answer":0,"chooseValue":"A"},{"id":"794930170250153985","questionId":"794930168371105793","content":"3","answer":0,"chooseValue":"B"},{"id":"794930170271125505","questionId":"794930168371105793","content":"4","answer":1,"chooseValue":"C"},{"id":"794930170292097025","questionId":"794930168371105793","content":"5","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930194208018433","title":"<p>使用图像扫描仪以300DPI 的分辨率扫描一幅3×4 英寸的图片，可以得到()像素的数字图像。</p>","analyze":"<p>DPI即每英寸像素点数量，图片大小为3*4英寸，那么面积为12平方英寸，扫描仪为300DPI，则每平方英寸应该有300*300个DPI，因此图像像素为12*300*300=900*1200。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930196103843841"],"itemList":[{"id":"794930196053512193","questionId":"794930194208018433","content":"300×300","answer":0,"chooseValue":"A"},{"id":"794930196070289409","questionId":"794930194208018433","content":"300×400","answer":0,"chooseValue":"B"},{"id":"794930196087066625","questionId":"794930194208018433","content":"900×4","answer":0,"chooseValue":"C"},{"id":"794930196103843841","questionId":"794930194208018433","content":"900×1200","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929958471356417","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">以下关于海明码的叙述中，正确的是（ </span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）。</span></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">海明码是利用奇偶性来检错和纠错的校验方法，码距最小为</span>2n+1<span style=\"font-family:宋体\">。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">A</span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929960321044481"],"itemList":[{"id":"794929960321044481","questionId":"794929958471356417","content":"海明码利用奇偶性进行检错和纠错","answer":1,"chooseValue":"A"},{"id":"794929960337821697","questionId":"794929958471356417","content":"海明码的码距为1","answer":0,"chooseValue":"B"},{"id":"794929960354598913","questionId":"794929958471356417","content":"海明码可以检错但不能纠错","answer":0,"chooseValue":"C"},{"id":"794929960371376129","questionId":"794929958471356417","content":"海明码中数据位的长度与校验位的长度必须相同","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929941442482177","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">彩色视频信号数字化的过程中，利用图像子采样技术通过降低对（</span>63）的采样频率，以达到减少数据量的目的。</span></p>","analyze":"<p><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 21pt;\">将彩色视频信号数字化时，利用图像子采样技术通过降低色度信号的采样频率，以减少数据量。</span><br/></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"font-family: 宋体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:宋体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">63）D </span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929943342501889"],"itemList":[{"id":"794929943296364545","questionId":"794929941442482177","content":"亮度信号","answer":0,"chooseValue":"A"},{"id":"794929943313141761","questionId":"794929941442482177","content":"饱和度信号","answer":0,"chooseValue":"B"},{"id":"794929943329918977","questionId":"794929941442482177","content":"同步信号","answer":0,"chooseValue":"C"},{"id":"794929943342501889","questionId":"794929941442482177","content":"色度信号","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929924447162369","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">浮点数在机器中的表示形式如下所示，若阶码的长度为</span>e，尾数的长度为m，则以下关于浮点表示的叙述中，正确的是</span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>18）</span></span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">。</span></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">①e的值影响浮点数的范围，e越大，所表示的浮点数值范围越大</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">②e的值影响浮点数的精度，e越大，所表示的浮点数精度越高</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">③m的值影响浮点数的范围，m越大，所表示的浮点数范围越大</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 0pt;\">④m的值影响浮点数的精度，m越大，所表示的浮点数精度越高</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\"><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/9a510f4b99fe9bc9740bde9fbec22d08.png?x-oss-process=style/ruankaodaren\"/></span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 21pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">在浮点表示方式下，浮点数的精度由尾数部分来确定，范围则取决于阶码的长度，因此阶码</span>e越大，所表示的浮点数值范围越大，尾数的位数m越大，所表示的浮点数精度越高。</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"> </span><span style=\"font-family: 宋体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:宋体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">C</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794929926355570689"],"itemList":[{"id":"794929926317821953","questionId":"794929924447162369","content":"①③","answer":0,"chooseValue":"A"},{"id":"794929926338793473","questionId":"794929924447162369","content":"②③","answer":0,"chooseValue":"B"},{"id":"794929926355570689","questionId":"794929924447162369","content":"①④","answer":1,"chooseValue":"C"},{"id":"794929926372347905","questionId":"794929924447162369","content":"②④","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930010552029185","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">显示深度、图像深度是图像显示的重要指标。当</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">时，显示器不能完全反映数字图像使用的全部颜色。</span></span></p>","analyze":"<p><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 20.7pt;\">图像深度图像文件中记录一个像素点所需要的位数，显示深度表示显示缓存中记录屏幕上一个点的位数，也即显示器可以显示的颜色数。因此，显示一幅图像时，屏幕上呈现的颜色效果与图文提供的颜色信息有关，也即与图像深度有关，同时也与显示器当前可容纳的颜色容量有关，也即与显示深度有关。</span><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">①显示深度大于图像深度：在这种情况下屏幕上的颜色能较真实地反映图像文件的颜色效果。显示的颜色完全取决于图像的颜色。</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">②显示深度等于图像深度：这种情况下如果用真彩色显示模式来显示真彩色图像，或者显示调色板与图像调色板一致时，屏幕上的颜色能较真实地反映图像文件的颜色效果；反之，显示调色板与图像调色板不一致时，显示色彩会出现失真。</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">③显示深度小于图像深度：此时显示的颜色会出现失真。</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">D</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930012485603329"],"itemList":[{"id":"794930012414300161","questionId":"794930010552029185","content":"显示深度=图像深度","answer":0,"chooseValue":"A"},{"id":"794930012439465985","questionId":"794930010552029185","content":"显示深度＞图像深度","answer":0,"chooseValue":"B"},{"id":"794930012464631809","questionId":"794930010552029185","content":"显示深度＞=图像深度","answer":0,"chooseValue":"C"},{"id":"794930012485603329","questionId":"794930010552029185","content":"显示深度＜图像深度","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930001995649025","title":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">Flynn</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">分类法基于信息流特征将计算机分成</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">4</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">类，其中</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">只有理论意义而无实例。</span></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">按照</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">Flynn</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">分类法，根据计算机中指令和数据的并行状况可把计算机分成：</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">单指令流单数据流</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">(SISD)——</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">传统的计算机包含单个</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">CPU</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">，它从存储在内存中的程序那里获得指令，并作用于单一的数据流。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">单指令流多数据流</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">(SIMD)——</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">单个的指令流作用于多于一个的数据流上。例如有数据</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">4</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">、</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">5</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">和</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">3</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">、</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">2</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">，一个单指令执行两个独立的加法运算：</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">4+5</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">和</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">3+2</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">，就被称为单指令流多数据流。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">SIMD</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">的一个例子就是一个数组或向量处理系统，它可以对不同的数据并行执行相同的操作。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">多指令流单数据流</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">(MISD)——</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">用多个指令作用于单个数据流的情况实际上很少见。这种冗余多用于容错系统。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">多指令流多数据流</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">(MIMD)——</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">这种系统类似于多个</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">SISD</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">系统。实际上，</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">MIMD</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">系统的一个常见例子是多处理器计算机，如</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">Sun</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">的企业级服务器。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">B</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930003887280129"],"itemList":[{"id":"794930003874697217","questionId":"794930001995649025","content":"SISD","answer":0,"chooseValue":"A"},{"id":"794930003887280129","questionId":"794930001995649025","content":"MISD","answer":1,"chooseValue":"B"},{"id":"794930003899863041","questionId":"794930001995649025","content":"SIMD","answer":0,"chooseValue":"C"},{"id":"794930003912445953","questionId":"794930001995649025","content":"MIMD","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930217046003713","title":"（ ）图像通过使用色彩查找表来获得图像颜色。","analyze":"在生成图像时，对图像中不同色彩进行采样，可产生包含各种颜色的颜色表，称为彩色查找表。描述图像每个像素的颜色也可以不由每个基色分量的数值直接决定，而是把像素值作为彩色查找表的表项入口地址，去找出相应的R、G、B强度值所产生的彩色。用这种方法描述的像素颜色称为伪彩色。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930218916663297"],"itemList":[{"id":"794930218895691777","questionId":"794930217046003713","content":"真彩色","answer":0,"chooseValue":"A"},{"id":"794930218916663297","questionId":"794930217046003713","content":"伪彩色","answer":1,"chooseValue":"B"},{"id":"794930218937634817","questionId":"794930217046003713","content":"黑白","answer":0,"chooseValue":"C"},{"id":"794930218958606337","questionId":"794930217046003713","content":"矢量","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930122791604225","title":"<p>在Cache-主存层次结构中，主存单元到Cache单元的地址转换由（）完成。</p>","analyze":"<p>在由Cache-主存构成的层次式存储系统中，为了提高地址转换速度，主存单元到Cache单元的地址转换采用硬件完成。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930124733566977"],"itemList":[{"id":"794930124733566977","questionId":"794930122791604225","content":"硬件","answer":1,"chooseValue":"A"},{"id":"794930124754538497","questionId":"794930122791604225","content":"寻址方式","answer":0,"chooseValue":"B"},{"id":"794930124775510017","questionId":"794930122791604225","content":"软件和少量的辅助硬件","answer":0,"chooseValue":"C"},{"id":"794930124792287233","questionId":"794930122791604225","content":"微程序","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929972618743809","title":"<p><span style=\"font-family: Calibri; font-size: 12pt;\">RGB 4:4:2</span><span style=\"font-family:宋体\">表示一幅彩色图像可生成的颜色数是</span><span style=\"font-family:Calibri\">____</span><span style=\"font-family:宋体\">种。</span></p><p class=\"p\"><br/></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">在多媒体计算机技术中，用得最多的是</span>RGB<span style=\"font-family:宋体\">彩色空间表示。因为计算机的彩色监视器的输入需要</span><span style=\"font-family:Calibri\">R</span><span style=\"font-family:宋体\">、</span><span style=\"font-family:Calibri\">G</span><span style=\"font-family:宋体\">、</span><span style=\"font-family:Calibri\">B</span><span style=\"font-family:宋体\">三个彩色分量，通过三个分量的不同比例，在显示屏幕上可以合成所需要的任意颜色，所以不管多媒体系统采用什么形式的彩色空间表示，最后的输出一定要转换成</span><span style=\"font-family:Calibri\">RGB</span><span style=\"font-family:宋体\">彩色空间表示。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">在本题中，因为</span>RGB<span style=\"font-family:宋体\">为</span><span style=\"font-family:Calibri\">4:4:2</span><span style=\"font-family:宋体\">，因此一共是</span><span style=\"font-family:Calibri\">10</span><span style=\"font-family:宋体\">位，所以可生成的颜色数是</span><span style=\"font-family:Calibri\">2</span></span><sup><span style=\"font-family: Calibri; font-size: 12pt; vertical-align: super;\">10</span></sup><span style=\"font-family: Calibri; font-size: 12pt;\">=1024<span style=\"font-family:宋体\">种。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">答案</span></span></strong><strong><span class=\"15\" style=\"font-family: 宋体;\">：</span></strong><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:Calibri\">B</span></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929974497792001"],"itemList":[{"id":"794929974481014785","questionId":"794929972618743809","content":"256","answer":0,"chooseValue":"A"},{"id":"794929974497792001","questionId":"794929972618743809","content":"1024","answer":1,"chooseValue":"B"},{"id":"794929974518763521","questionId":"794929972618743809","content":"4096","answer":0,"chooseValue":"C"},{"id":"794929974535540737","questionId":"794929972618743809","content":"65536","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929964129472513","title":"<p><span style=\"font-family: Calibri; font-size: 10.5pt;\"><span style=\"font-family:宋体\">目前，计算机系统中常用的三级存储体系是</span>_</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> </span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span></span><span style=\"font-family: Calibri; font-size: 10.5pt;\">_<span style=\"font-family:宋体\">。</span><span style=\"font-family:Calibri\"> </span></span></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">计算机的存储系统采用分级存储体系的理论依据是程序访问的局部性原理。</span>CPU<span style=\"font-family:宋体\">访问存储器时，无论是取指令还是存取数据，所访问的存储单元都趋于聚集在一个较小的连续区域中。局部性分为两种，分别是时间局部性和空间局部性。时间局部性是指如果一个信息项正在被访问，那么在近期它很可能还会被再次访问。程序循环、堆栈等是产生时间局部性的原因。空间局部性是指在最近的将来将用到的信息很可能与现在正在使用的信息在空间地址上是临近的。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">计算机系统中常用的三级存储体系是指</span>cache<span style=\"font-family:宋体\">、主存、辅存，这三个级别容量越来越大，价格越来越低，速度越来越慢。</span></span></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794929966050463745"],"itemList":[{"id":"794929966016909313","questionId":"794929964129472513","content":"寄存器、内存、外存","answer":0,"chooseValue":"A"},{"id":"794929966033686529","questionId":"794929964129472513","content":"寄存器、cache、内存","answer":0,"chooseValue":"B"},{"id":"794929966050463745","questionId":"794929964129472513","content":"cache、主存、辅存","answer":1,"chooseValue":"C"},{"id":"794929966067240961","questionId":"794929964129472513","content":"L0、L1、L2三级cache","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929891165360129","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">Flynn分类法根据计算机在执行程序的过程中</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">将计算机分为</span>4类。当前主流的多核计算机属于</span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>15）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">Flynn于1972年提出计算平台分类法主要根据指令流和数据流来分类，分为四类：</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">①单指令流单数据流机器(SISD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">SISD机器是一种传统的串行计算机，其硬件不支持任何形式的并行计算，所有的指令都是串行执行，并且在某个时钟周期内，CPU只能处理一个数据流。早期的计算机都是SISD机器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">②单指令流多数据流机器(SIMD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">SIMD是采用一个指令流处理多个数据流。这类机器在数字信号处理、图像处理，以及多媒体信息处理等领域非常有效。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">Intel处理器实现的MMXTM、SSE(StreamingSIMDExtensions)、SSE2及SSE3扩展指令集，都能在单个时钟周期内处理多个数据单元。也就是说人们现在用的单核计算机基本上都属于SIMD机器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">③多指令流单数据流机器(MISD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MISD是采用多个指令流来处理单个数据流。在实际情况中，采用多指令流处理多数据流才是更有效的方法，因此MISD只是作为理论模型出现，没有实际应用。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">④多指令流多数据流机器(MIMD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MIMD机器可以同时执行多个指令流，这些指令流分别对不同数据流进行操作。最新的多核计算平台就属于MIMD的范畴，例如Intel和AMD的双核处理器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">15）</span><span style=\"font-family: 宋体; font-size: 10.5pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929893145071617"],"itemList":[{"id":"794929893077962753","questionId":"794929891165360129","content":"SISD","answer":0,"chooseValue":"A"},{"id":"794929893098934273","questionId":"794929891165360129","content":"SIMD","answer":0,"chooseValue":"B"},{"id":"794929893124100097","questionId":"794929891165360129","content":"MISD","answer":0,"chooseValue":"C"},{"id":"794929893145071617","questionId":"794929891165360129","content":"MIMD","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929955640201217","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span face=\"宋体\">计算机系统的主存主要是由（ </span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span face=\"宋体\">）构成的。</span></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><br/></p>","analyze":"<p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span face=\"宋体\">主存主要采用动态随机存储器</span>DRAM<span face=\"宋体\">，</span><span face=\"Calibri\">Cache</span><span face=\"宋体\">采用静态随机存储器</span><span face=\"Calibri\">SRAM</span><span face=\"宋体\">，</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">EEPROM</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span face=\"宋体\">是电擦除可编程的只读存储器。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: rgb(127, 127, 127);\"><span face=\"黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span face=\"宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">A</span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929957502472193"],"itemList":[{"id":"794929957502472193","questionId":"794929955640201217","content":"DRAM","answer":1,"chooseValue":"A"},{"id":"794929957523443713","questionId":"794929955640201217","content":"SRAM","answer":0,"chooseValue":"B"},{"id":"794929957544415233","questionId":"794929955640201217","content":"Cache","answer":0,"chooseValue":"C"},{"id":"794929957565386753","questionId":"794929955640201217","content":"EEPROM","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929930138832897","title":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%; text-indent: 0pt; margin-left: 0pt;\"><span style=\"line-height: 150%; font-family: 宋体; font-size: 10.5pt; mso-spacerun: "yes"; mso-font-kerning: 1.0000pt;\"><span style=\"font-family: 宋体;\">流水线技术是通过并行硬件来提高系统性能的常用方法。对于一个</span>k段流水线，假设其各段的执行时间均相等（设为t），输入到流水线中的任务是连续的理想情况下，完成n个连续任务需要的总时间为（ ）。若某流水线浮点加法运算器分为5段，所需要的时间分别是6ns、7ns、8ns、9ns和6ns，则其最da加速比为</span><span style=\"text-decoration: underline;\"><span style=\"line-height: 150%; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family: 宋体;\">（</span>请作答此空）</span></span><span style=\"line-height: 150%; font-family: 宋体; font-size: 10.5pt; mso-spacerun: "yes"; mso-font-kerning: 1.0000pt;\"><span style=\"font-family: 宋体;\">。</span></span></p>","analyze":"<p>对于一个k段流水线，假设其各段的执行时间均相等（设为t），输入到流水线中的任务是连续的理想情况下，从流水线的输出端看，用k个时钟周期输出第yi项任务，其余n-1个时钟周期，每个周期输出一项任务，因此完成n个连续任务需要的总时间为(k+n-l)t。加速比定义为顺序执行时间与流水线执行时间的比值，根据题干假设，顺序执行时间为6+7+8+9+6=36，该流水线为5段，执行时间最长的第四段9ns，作为流水线总的执行时间。因此加速比为36/9=4。</p><p><span style=\"line-height: 150%; font-family: 宋体; font-size: 10.5pt; mso-spacerun: "yes"; mso-font-kerning: 1.0000pt;\"></span><span style=\"line-height: 150%; font-family: 宋体; font-size: 10.5pt; mso-spacerun: "yes"; mso-font-kerning: 1.0000pt;\"></span><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%; text-indent: 0pt; margin-left: 0pt;\"><span style=\"background: #7F7F7F; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family: 宋体;\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family: 宋体;\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> (59) A </span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929932001103873"],"itemList":[{"id":"794929932001103873","questionId":"794929930138832897","content":"4","answer":1,"chooseValue":"A"},{"id":"794929932017881089","questionId":"794929930138832897","content":"5","answer":0,"chooseValue":"B"},{"id":"794929932030464001","questionId":"794929930138832897","content":"6","answer":0,"chooseValue":"C"},{"id":"794929932047241217","questionId":"794929930138832897","content":"7","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930072023748609","title":"下面表述不正确的是（ ）。","analyze":"累加寄存器AC：通用寄存器，为ALU提供一个工作区，用来暂存数据。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930073911185409"],"itemList":[{"id":"794930073890213889","questionId":"794930072023748609","content":"算术逻辑单元可以进行数据的算术运算和逻辑运算。","answer":0,"chooseValue":"A"},{"id":"794930073911185409","questionId":"794930072023748609","content":"数据缓冲寄存器为ALU提供一个工作区，用来暂存数据。","answer":1,"chooseValue":"B"},{"id":"794930073923768321","questionId":"794930072023748609","content":"地址寄存器用来保存当前CPU所访问的内存单元的地址。","answer":0,"chooseValue":"C"},{"id":"794930073940545537","questionId":"794930072023748609","content":"程序计数器用来存储下一条要执行指令的地址。","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930007716679681","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">以下媒体中</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">是表现媒体。</span></span></p>","analyze":"<p><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 20.7pt;\">表现媒体是指进行信息输入和输出的媒体，如：键盘、鼠标、扫捕仪、话筒和摄像机等输入媒体以及显示器、打印机和扬声器等输出媒体。</span><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930009608310785"],"itemList":[{"id":"794930009557979137","questionId":"794930007716679681","content":"声音","answer":0,"chooseValue":"A"},{"id":"794930009574756353","questionId":"794930007716679681","content":"声音编码","answer":0,"chooseValue":"B"},{"id":"794930009591533569","questionId":"794930007716679681","content":"超声波","answer":0,"chooseValue":"C"},{"id":"794930009608310785","questionId":"794930007716679681","content":"喇叭","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930239644913665","title":"计算机系统是一个硬件和软件综合体，位于硬联逻辑层上面的微程序是用微指令编写的。以下叙述中，正确的是， （7） 。","analyze":"传统机器级的机器语言是该机的指令集，程序员用机器指令编写的程序可以由微程序进行解释。","multi":0,"questionType":1,"answer":"A","chooseItem":["794930241490407425"],"itemList":[{"id":"794930241490407425","questionId":"794930239644913665","content":"程序员用机器指令编写的程序可以由微程序进行解释","answer":1,"chooseValue":"A"},{"id":"794930241507184641","questionId":"794930239644913665","content":"微程序一般是由操作系统来调度和执行","answer":0,"chooseValue":"B"},{"id":"794930241528156161","questionId":"794930239644913665","content":"微程序一般用高级语言构造的编译器翻译后来执行","answer":0,"chooseValue":"C"},{"id":"794930241540739073","questionId":"794930239644913665","content":"微程序一般用高级语言构造的解释器件来解释执行","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930110997221377","title":"<p>内存按字节编址，地址从90000H到CFFFFH，若用存储容量为16K×8bit的存储器芯片构成该内存，至少需要（）片。</p>","analyze":"<p>内存按字节编址，地址从90000H到CFFFFH时，存储单元数为CFFFFH-90000H+1=40000H，即2^18B。若存储芯片的容量为16K×8bit，则需2^18/16KB=2^4个芯片组成该内存。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930112939184129"],"itemList":[{"id":"794930112897241089","questionId":"794930110997221377","content":"2","answer":0,"chooseValue":"A"},{"id":"794930112914018305","questionId":"794930110997221377","content":"4","answer":0,"chooseValue":"B"},{"id":"794930112926601217","questionId":"794930110997221377","content":"8","answer":0,"chooseValue":"C"},{"id":"794930112939184129","questionId":"794930110997221377","content":"16","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930222699925505","title":"<p>从基本的CPU工作原理来看，若CPU执行MOV R1，R0指令(即将寄存器R0的内容传送到寄存器R1中)，则CPU首先要完成的操作是 （） (其中PC为程序计数器；M为主存储器；DR为数据寄存器；IR为指令寄存器；AR为地址寄存器)。</p>","analyze":"<p> CPU执行MOVRI，RO指令，CPU首先要完成的操作是从内存中读取该指令的指令操作码。取该指令的指令操作码，首先要做的就是将程序计数器的内容送到地址寄存器，即PC→AR。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930224578973697"],"itemList":[{"id":"794930224549613569","questionId":"794930222699925505","content":"(R0)→R1","answer":0,"chooseValue":"A"},{"id":"794930224578973697","questionId":"794930222699925505","content":"PC→AR ","answer":1,"chooseValue":"B"},{"id":"794930224599945217","questionId":"794930222699925505","content":"M→DR","answer":0,"chooseValue":"C"},{"id":"794930224625111041","questionId":"794930222699925505","content":"DR→IR","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930093884461057","title":"<p>以下关于CPU的叙述中，错误的是（）。</p>","analyze":"<p>CPU是计算机的控制中心，主要由运算器、控制器、寄存器组和内部总线等部件组成。控制器由程序计数器、指令寄存器、指令译码器、时序产生器和操作控制器组成，它是发布命令的“决策机构”，即完成协调和指挥整个计算机系统的操作。它的主要功能有：从内存中取出一条指令，并指出下一条指令在内存中的位置；对指令进行译码或测试，并产生相应的操作控制信号，以便启动规定的动作；指挥并控制CPU、内存和输入输出设备之间数据的流动。</p><p>程序计数器(PC)是专用寄存器，具有寄存信息和计数两种功能，又称为指令计数器，在程序开始执行前，将程序的起始地址送入PC，该地址在程序加载到内存时确定，因此PC的初始内容即是程序第一条指令的地址。执行指令时，CPU将自动修改PC的内容，以便使其保持的总是将要执行的下一条指令的地址。由于大多数指令都是按顺序执行的，因此修改的过程通常只是简单地对PC加1。当遇到转移指令时，后继指令的地址根据当前指令的地址加上一个向前或向后转移的位移量得到，或者根据转移指令给出的直接转移的地址得到。</p><p>答案：B</p><p><br/></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930095767703553"],"itemList":[{"id":"794930095746732033","questionId":"794930093884461057","content":"CPU产生每条指令的操作信号并将操作信号送往相应的部件进行控制","answer":0,"chooseValue":"A"},{"id":"794930095767703553","questionId":"794930093884461057","content":"程序计数器PC除了存放指令地址，也可以临时存储算术/逻辑运算结果","answer":1,"chooseValue":"B"},{"id":"794930095792869377","questionId":"794930093884461057","content":"CPU中的控制器决定计算机运行过程的自动化","answer":0,"chooseValue":"C"},{"id":"794930095818035201","questionId":"794930093884461057","content":"指令译码器是CPU控制器中的部件","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930102474395649","title":"<p>假设系统中有三类互斥资源R1、R2和R3，可用资源数分别为9、8和5。在T0时刻系统中有P1、P2、P3、P4和P5五个进程，这些进程对资源的最大需求量和已分配资源数如下表所示。如果进程按 ( ) 序列执行，那么系统状态是安全的。<br/><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/46181223e51dbf4a4fc68431b839680e.jpg?x-oss-process=style/ruankaodaren\" title=\"46181223e51dbf4a4fc68431b839680e.jpg\" alt=\"1.jpg\"/></p>","analyze":"<p>本题考查的是操作系统进程管理中死锁检测的多项资源银行家算法。</p><p>当前剩余资源量为(2，1，0)，具体算法是R1、R2、R3的总资源数分别减去已分配资源数，进程尚需资源数为</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/2aeda2885237b35dd066934b89fa8029.jpg?x-oss-process=style/ruankaodaren\" title=\"2aeda2885237b35dd066934b89fa8029.jpg\" alt=\"2.jpg\"/></p><p>P2还需资源(0，1，0)，而此时系统可用资源为(2，1，0)能满足条件，故P2能运行完，作上完成标志true，如下表所示。P2释放资源后系统的可用资源为(4，2， 1)：此时P4尚需资源(0，0，1)，系统能满足P4的请求，故P4能运行完，作上完成标志true，P4释放资源后系统的可用资源为(5，4，1)；此时P5尚需资源(3，4，4)，系统能满足P5的请求，故P5能运行完，作上完成标志true，P5释放资源后系统的可用资源为(6，5，4)；依此类推。进程可按P2→P4→P5→P1→P3的顺序执行，每个进程都可以获得需要的资源运行完毕，做上完成标记，所以系统的状态是安全的。</p><p>根据试题的可选答案，正确的答案应为C。<br/><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/0b67f02e7adce99f274fbe7e275e8c73.jpg?x-oss-process=style/ruankaodaren\" title=\"0b67f02e7adce99f274fbe7e275e8c73.jpg\" alt=\"1.jpg\"/> </p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930104361832449"],"itemList":[{"id":"794930104319889409","questionId":"794930102474395649","content":"P1→P2→P4→P5→P3","answer":0,"chooseValue":"A"},{"id":"794930104336666625","questionId":"794930102474395649","content":"P2→P1→P4→P5→P3","answer":0,"chooseValue":"B"},{"id":"794930104361832449","questionId":"794930102474395649","content":"P2→P4→P5→P1→P3","answer":1,"chooseValue":"C"},{"id":"794930104382803969","questionId":"794930102474395649","content":"P4→P2→P5→P1→P3","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930197014007809","title":"<p>数字语音的采样频率定义为10kHz，这是因为( )。</p>","analyze":"<p>声音的采样频率一般为最高频率的两倍，可以保证不失真。记住关于声音频率有个两倍的概念即可。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930198985330689"],"itemList":[{"id":"794930198985330689","questionId":"794930197014007809","content":"语音信号定义的频率最高值为5kHz","answer":1,"chooseValue":"A"},{"id":"794930199014690817","questionId":"794930197014007809","content":"语音信号定义的频率最高值为8kHz","answer":0,"chooseValue":"B"},{"id":"794930199035662337","questionId":"794930197014007809","content":"数字语音转输线路的带宽只有8kHz","answer":0,"chooseValue":"C"},{"id":"794930199060828161","questionId":"794930197014007809","content":"一般声卡的采样频率最高为每秒8k 次","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929969800171521","title":"<p><span style=\"font-family:宋体\">信息具有许多质量属性，对于市场情报信息来说，至关重要的属性是</span><span style=\"font-family: Calibri; font-size: 12pt;\">____</span><span style=\"font-family:宋体\">。</span><span style=\"font-family:Calibri\"> </span></p><p class=\"p\"><br/></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:宋体\">有用的信息对于质量属性的要求是不一样的。对于市场情报信息来说，一些不准确和不完全性是可以忍受的，至关重要的是时间性，比如，市场情报信息能够在竞争对手将要做出大幅度减价的时候发出警示，要尽早制订计划如何应对，相比之下，具体的价格细节和改变时间就并非是最重要的。</span></span><span style=\"font-family: Calibri; font-size: 12pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">答案</span></span></strong><strong><span class=\"15\" style=\"font-family: 宋体;\">：</span></strong><span style=\"font-family: Calibri; font-size: 12pt;\"><span style=\"font-family:Calibri\">A</span></span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929971641470977"],"itemList":[{"id":"794929971641470977","questionId":"794929969800171521","content":"及时性","answer":1,"chooseValue":"A"},{"id":"794929971658248193","questionId":"794929969800171521","content":"完整性","answer":0,"chooseValue":"B"},{"id":"794929971675025409","questionId":"794929969800171521","content":"完全性","answer":0,"chooseValue":"C"},{"id":"794929971695996929","questionId":"794929969800171521","content":"安全性","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930069070958593","title":"机器字长为n位的二进制数可以用补码来表示（ ）个不同的有符号定点小数。","analyze":"<p>本题考查计算机体系结构中计算机科学基础内数据的表示这一知识点。各种码制下带符号数的表示范围如下表所示。</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/f870454601c6717c58d3be68a21ef5d9.jpg?x-oss-process=style/ruankaodaren\" title=\"f870454601c6717c58d3be68a21ef5d9.jpg\" alt=\"1.jpg\"/></p><p>补码表示定点小数，范围是：[-1,(1-2^(-n+1))]，这个范围一共有2n 个数。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930070991949825"],"itemList":[{"id":"794930070991949825","questionId":"794930069070958593","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/a5b3784820bdc5cf146392ca26a68466.jpg?x-oss-process=style/ruankaodaren\" title=\"a5b3784820bdc5cf146392ca26a68466.jpg\" alt=\"1.jpg\"/>","answer":1,"chooseValue":"A"},{"id":"794930071004532737","questionId":"794930069070958593","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/381e284fa3abb69fba1f657e6cd3bc97.jpg?x-oss-process=style/ruankaodaren\" title=\"381e284fa3abb69fba1f657e6cd3bc97.jpg\" alt=\"2.jpg\"/>","answer":0,"chooseValue":"B"},{"id":"794930071021309953","questionId":"794930069070958593","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/be71377e0ceaa8ffa0088fb9cc6ea061.jpg?x-oss-process=style/ruankaodaren\" title=\"be71377e0ceaa8ffa0088fb9cc6ea061.jpg\" alt=\"3.jpg\"/>","answer":0,"chooseValue":"C"},{"id":"794930071042281473","questionId":"794930069070958593","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/cf92c68fc89f6d87c1f535c46b9323c9.jpg?x-oss-process=style/ruankaodaren\" title=\"cf92c68fc89f6d87c1f535c46b9323c9.jpg\" alt=\"4.jpg\"/>","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930253771329537","title":"<p>矢量图是常用的图形图像表示形式， （13） 是它的优势。</p>","analyze":"<p>计算机的图有“图形”矢量图和图像两种形式。</p><p>图像方式用像素组成图像，兼容性好、含有大量细节，适合存储照片。“图形”矢量图则使用点、直线、多边形等基于数学方程的几何图元表示图像，需要用兼容的软件才能打开，优点是可以自由缩放。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930255776206849"],"itemList":[{"id":"794930255671349249","questionId":"794930253771329537","content":"兼容性好","answer":0,"chooseValue":"A"},{"id":"794930255709097985","questionId":"794930253771329537","content":"适合存储照片","answer":0,"chooseValue":"B"},{"id":"794930255742652417","questionId":"794930253771329537","content":"含有大量细节","answer":0,"chooseValue":"C"},{"id":"794930255776206849","questionId":"794930253771329537","content":"自由缩放","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929950019833857","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">某四级指令流水线分别完成取指、取数、运算、保存结果四步操作。若完成上述操作的时间依次为</span> 8ns<span style=\"font-family:宋体\">、</span><span style=\"font-family:Calibri\">9ns</span><span style=\"font-family:宋体\">、 </span><span style=\"font-family:Calibri\">4ns</span><span style=\"font-family:宋体\">、</span><span style=\"font-family:Calibri\">8ns</span><span style=\"font-family:宋体\">，则该流水线的操作周期应至少为（ </span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span>ns <span style=\"font-family:宋体\">。</span></span><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">流水线的周期为指令执行时间最长的一段。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">C</span></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794929951907270657"],"itemList":[{"id":"794929951873716225","questionId":"794929950019833857","content":"4","answer":0,"chooseValue":"A"},{"id":"794929951890493441","questionId":"794929950019833857","content":"8","answer":0,"chooseValue":"B"},{"id":"794929951907270657","questionId":"794929950019833857","content":"9","answer":1,"chooseValue":"C"},{"id":"794929951928242177","questionId":"794929950019833857","content":"33","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929932957405185","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">总线规范会详细描述总线各方面的特性，其中（</span>60）特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。</span></p>","analyze":"<p><span style=\"font-family:宋体\">总线规范会详细描述总线各方面的特性，其中物理特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总线周期中并行传输</span><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 21pt;\">4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为 (4/2)x10=20 Mbps。</span><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:宋体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">60）A </span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929934815481857"],"itemList":[{"id":"794929934815481857","questionId":"794929932957405185","content":"物理","answer":1,"chooseValue":"A"},{"id":"794929934832259073","questionId":"794929932957405185","content":"电气","answer":0,"chooseValue":"B"},{"id":"794929934849036289","questionId":"794929932957405185","content":"功能","answer":0,"chooseValue":"C"},{"id":"794929934865813505","questionId":"794929932957405185","content":"时间","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930066218831873","title":"为了优化系统的性能，有时需要对系统进行调整。对于不同的系统，其调整参数也不尽相同。例如，对于数据库系统，主要包括CPU/内存使用状况、（ ）、进程/线程使用状态、日志文件大小等；对于应用系统，主要包括应用系统的可用性、响应时间、（请作答此空）、特定应用资源占用等。","analyze":"为了优化系统性能，有时需要对系统进行调整。对于数据库系统，性能调整主要包括CPU/内存使用状况、优化数据库设计、优化数据库管理、进程/线程状态、硬盘剩余空间、查询语句性能、日志文件大小等；对于应用系统，性能调整主要包括应用系统的可用性、响应时间、并发用户数，以及特定应用的系统资源占用等。","multi":0,"questionType":1,"answer":"A","chooseItem":["794930068085297153"],"itemList":[{"id":"794930068085297153","questionId":"794930066218831873","content":"并发用户数","answer":1,"chooseValue":"A"},{"id":"794930068102074369","questionId":"794930066218831873","content":"支持协议和标准","answer":0,"chooseValue":"B"},{"id":"794930068118851585","questionId":"794930066218831873","content":"最大连接数","answer":0,"chooseValue":"C"},{"id":"794930068135628801","questionId":"794930066218831873","content":"时延抖动","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930083432255489","title":"在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式（包括无条件传送与程序查询方式）、程序中断方式、DMA工作方式、通道方式、I/O处理机。（）方式I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，并且只适用于简单的I/O控制。（）允许主存储器和I/O设备之间通过某种控制器直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。 （）在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入。（请作答此空）指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。上述工作方式中，（ ）工作方式CPU与I/O设备是串行工作的。","analyze":"<p>在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式、程序中断方式、DMA工作方式、通道方式、I/O处理机。</p><p>1、程序控制方式</p><p>分为无条件查询和程序查询方式。</p><p> ① 无条件传送方式，I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，而cpu在需要时，随时直接利用I/O指令访问相应的I/O端口，实现与外设的数据交换。优点是软、硬件结构简单，缺点是对时序要求高，只适用于简单的I/O控制。</p><p>② 程序查询方式</p><p>程序查询方式也称为程序轮询方式，该方式采用用户程序直接控制主机与外部设备之间输入/输出操作。CPU必须不停地循环测试I/O设备的状态端口，当发现设备处于准备好(Ready)状态时，CPU就可以与I/O设备进行数据存取操作。这种方式下的CPU与I/O设备是串行工作的。</p><p>2、中断方式</p><p>当I/O设备结束(完成、特殊或异常)时，就会向CPU发出中断请求信号，CPU收到信号就可以采取相应措施。当某个进程要启动某个设备时，CPU就向相应的设备控制器发出一条设备I/O启动指令，然后CPU又返回做原来的工作。CPU与I/O设备可以并行工作，与程序查询方式相比，大大提高了CPU的利用率。</p><p>3、DMA(直接内存存取)方式</p><p>DMA方式也称为直接主存存取方式，其思想是：允许主存储器和I/O设备之间通过“DMA控制器(DMAC)”直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。</p><p>4、通道控制方式</p><p>在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入，使主机和外设并行工作程度更高。</p><p>5、I/O处理机</p><p>指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930085298720769"],"itemList":[{"id":"794930085298720769","questionId":"794930083432255489","content":"I/O处理机","answer":1,"chooseValue":"A"},{"id":"794930085311303681","questionId":"794930083432255489","content":"DMA方式","answer":0,"chooseValue":"B"},{"id":"794930085328080897","questionId":"794930083432255489","content":"通道控制方式","answer":0,"chooseValue":"C"},{"id":"794930085344858113","questionId":"794930083432255489","content":"中断方式","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930242450903041","title":"<p>假如有5块80G和2块60G的硬盘，采用RAID5的容量是 （9） 。</p>","analyze":"<p>RAID5实际容量=（总盘块数-1）×最小磁盘的容量</p><p>因此，采用RAID5的容量=（7-1）×60G=360G。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930244338339841"],"itemList":[{"id":"794930244304785409","questionId":"794930242450903041","content":"240G","answer":0,"chooseValue":"A"},{"id":"794930244321562625","questionId":"794930242450903041","content":"300G","answer":0,"chooseValue":"B"},{"id":"794930244338339841","questionId":"794930242450903041","content":"360G","answer":1,"chooseValue":"C"},{"id":"794930244350922753","questionId":"794930242450903041","content":"480G","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930096740782081","title":"在中断响应过程中，CPU保护程序计数器的主要目的是（）。","analyze":"<p>中断响应实现向中断服务程序的过渡。在中断响应周期，CPU要完成以下操作：</p><p>(1)发出中断响应信号INTA。</p><p>(2)关中断，即将IF位清0。这是因为在响应一个中断的期间不能响应另一个中断。</p><p>(3)保护断点和标志寄存器。</p><p>断点是按正常顺序(即没有中断)应执行的下一条指令的地址。对8086来说，保护断点就是保存CS和IP的内容(压入堆栈)。标志寄存器FR中存放着刚执行指令的一些重要特征，也需要保存起来，以便中断返回时继续使用其中的内容。</p><p>(4)查找中断源，转向相应的中断服务程序的入口。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930098670161921"],"itemList":[{"id":"794930098636607489","questionId":"794930096740782081","content":"使CPU能找到中断服务程序的入口地址","answer":0,"chooseValue":"A"},{"id":"794930098649190401","questionId":"794930096740782081","content":"为了实现中断嵌套","answer":0,"chooseValue":"B"},{"id":"794930098670161921","questionId":"794930096740782081","content":"为了使CPU在执行完中断服务程序时能回到被中断程序的断点处","answer":1,"chooseValue":"C"},{"id":"794930098682744833","questionId":"794930096740782081","content":"为了使CPU与I/O设备并行工作","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930174066970625","title":"显示器的 （62） 是指屏幕上能够显示出的像素数目。","analyze":"显示分辨率指的是显示屏上能够显示的像素数目，如1024*768表示显示屏分为768行（垂直分辨率），每行（水平分辨率）显示1024个像素。","multi":0,"questionType":1,"answer":"D","chooseItem":["794930176176705537"],"itemList":[{"id":"794930176126373889","questionId":"794930174066970625","content":"对比度","answer":0,"chooseValue":"A"},{"id":"794930176143151105","questionId":"794930174066970625","content":"响应时间","answer":0,"chooseValue":"B"},{"id":"794930176159928321","questionId":"794930174066970625","content":"刷新频率","answer":0,"chooseValue":"C"},{"id":"794930176176705537","questionId":"794930174066970625","content":"显示分辨率","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930208477040641","title":"内存按字节编址，地址从90000H到CFFFFH，若用存储容量为16KB×8bit的存储器芯片构成该内存，至少需要（ ）片。","analyze":"内存按字节编址，地址从90000H到CFFFFH时，存储单元数为CFFFFH-90000H= 3FFFFH，即2^18B。若存储芯片的容量为16K×8bit，则需2^18/16KB=2^4个芯片组成该内存。","multi":0,"questionType":1,"answer":"D","chooseItem":["794930210431586305"],"itemList":[{"id":"794930210343505921","questionId":"794930208477040641","content":"2","answer":0,"chooseValue":"A"},{"id":"794930210372866049","questionId":"794930208477040641","content":"4","answer":0,"chooseValue":"B"},{"id":"794930210402226177","questionId":"794930208477040641","content":"8","answer":0,"chooseValue":"C"},{"id":"794930210431586305","questionId":"794930208477040641","content":"16","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930264361947137","title":"下列做法中不利于嵌入式应用软件移植的是（）。","analyze":"<p>本题考查嵌入式系统的基础知识。</p><p>嵌入式应用软件是针对特定应用领域，基于某一固定的硬件平台，用来达到用户预期目标的计算机软件。由于用户任务可能有时间和精度上的要求，因此有些嵌入式应用软件需要特定嵌入式操作系统的支持。嵌入式应用软件和普通应用软件有一定的区别，它不仅要求其准确性、安全性和稳定性等方面能够满足实际应用的需要，而且还要尽可能地进行优化，以减少对系统资源的消耗，降低硬件成本。</p><p>嵌入式软件的特点有：</p><p> (1)嵌入式软件具有独特的实用性。嵌入式软件是为嵌入式系统服务的，这就要求它与外部硬件和设备联系紧密。嵌入式系统以应用为中心，根据应用需求定向开发，面向产业、面向市场，需要特定的行业经验。每种嵌入式软件都有自己独特的应用环境和实用价值。</p><p> (2)嵌入式软件应有灵活的适用性。嵌入式软件通常可以认为是一种模块化软件，它应该能非常方便灵活地运用到各种嵌入式系统中，而不能破坏或更改原有的系统特性和功能。首先它要小巧，不能占用大量资源；其次要使用灵活，应尽量优化配置，减小对系统的整体继承性，升级更换灵活方便。</p><p>综上所述，嵌入式软件和硬件平台密切相关，不同的硬件平台可能使用不同的编译器，直接使用C语言的数据类型，会引入硬件平台和软件平台带来的差异，不利于软件移植。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930266270355457"],"itemList":[{"id":"794930266249383937","questionId":"794930264361947137","content":"在软件设计上，采用层次化设计和模块化设计","answer":0,"chooseValue":"A"},{"id":"794930266270355457","questionId":"794930264361947137","content":"在数据类型上，尽量直接使用C语言的数据类型","answer":1,"chooseValue":"B"},{"id":"794930266282938369","questionId":"794930264361947137","content":"将不可移植的部分局域化，集中在某几个特定的文件之中","answer":0,"chooseValue":"C"},{"id":"794930266299715585","questionId":"794930264361947137","content":"软件体系结构设计时，在操作系统和应用软件之间引入一个中间件层","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930131486396417","title":"从基本的CPU工作原理来看，若CPU执行MOV R1，R0指令(即将寄存器R0的内容传送到寄存器R1中)，则CPU首先要完成的操作是 （ 2 ） (其中PC为程序计数器；M为主存储器；DR为数据寄存器；IR为指令寄存器；AR为地址寄存器)。","analyze":"CPU执行MOVRI，RO指令，CPU首先要完成的操作是从内存中读取该指令的指令操作码。取该指令的指令操作码，首先要做的就是将程序计数器的内容送到地址寄存器，即PC→AR。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930133361250305"],"itemList":[{"id":"794930133340278785","questionId":"794930131486396417","content":"(R0)→R1","answer":0,"chooseValue":"A"},{"id":"794930133361250305","questionId":"794930131486396417","content":"PC→AR","answer":1,"chooseValue":"B"},{"id":"794930133378027521","questionId":"794930131486396417","content":"M→DR","answer":0,"chooseValue":"C"},{"id":"794930133398999041","questionId":"794930131486396417","content":"DR→IR","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929916821917697","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">MPEG-1视频编码标准</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">中没有使用帧间编码能够直接作为索引点的是</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>63）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">试题解析：</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MPEG-1标准中，视频图像的帧序列包括帧内图像(I帧)、预测图像(P帧</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">和插补图像</span>(B帧</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">，或称双向预测图像</span>3种。帧内图像不参照任何过去的或者将来的其他图像帧，压缩编码直接采用类JPEG的压缩算法，故其可以直接作为索引和访问点；预测图像使用基于运动补偿的单向帧间预测编码；而插补图像则使用双向帧间预测编码。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>63）</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> A</span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929918696771585"],"itemList":[{"id":"794929918696771585","questionId":"794929916821917697","content":"I帧","answer":1,"chooseValue":"A"},{"id":"794929918717743105","questionId":"794929916821917697","content":"P帧","answer":0,"chooseValue":"B"},{"id":"794929918738714625","questionId":"794929916821917697","content":"B帧","answer":0,"chooseValue":"C"},{"id":"794929918755491841","questionId":"794929916821917697","content":"S帧","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929899725934593","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">关于大规模并行处理器</span>MPP，以下说法不正确的是</span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>18）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">大规模并行处理</span>MPP(Massively Parallel Processing)系统是指使用专用通信网络构成的大型多机系统。每个节点都是一个完全独立的计算机，节点间采用分布式存储器结构，节点间通信采用消息机制，可包容多处理器系统。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">大多数</span>MPP系统使用标准的CPU作为它们的处理器，常用的有Intel Pentium系列、Sun UltraSPARC和IBM PowerPC等。MPP系统使用高性能的定制的高速互连网络及网络接口，可以在低延迟和高带宽的条件下传递消息。MPP是一种异步的分布式存储器结构的MIMD系统，它的程序有多个进程，分布在各个微处理器上，每个进程有自己独立的地址空间，进程之间以消息传递进行相互通信。大规模的MPP系统使用特殊的硬件和软件来监控系统、检测错误并从错误中平滑地恢复。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：（</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">18）</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">B</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929901609177089"],"itemList":[{"id":"794929901588205569","questionId":"794929899725934593","content":"大多数MPP系统使用标准的CPU作为它们的处理器","answer":0,"chooseValue":"A"},{"id":"794929901609177089","questionId":"794929899725934593","content":"其互连网络通常采用商用的以太网实现","answer":1,"chooseValue":"B"},{"id":"794929901625954305","questionId":"794929899725934593","content":"是一种异步的分布式存储器结构的MIMD系统","answer":0,"chooseValue":"C"},{"id":"794929901642731521","questionId":"794929899725934593","content":"使用特殊的硬件和软件来监控系统、检测错误并从错误中平滑地恢复","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930063404453889","title":"为了优化系统的性能，有时需要对系统进行调整。对于不同的系统，其调整参数也不尽相同。例如，对于数据库系统，主要包括CPU/内存使用状况、（请作答此空）、进程/线程使用状态、日志文件大小等；对于应用系统，主要包括应用系统的可用性、响应时间、（ ）、特定应用资源占用等。","analyze":"为了优化系统性能，有时需要对系统进行调整。对于数据库系统，性能调整主要包括CPU/内存使用状况、优化数据库设计、优化数据库管理、进程/线程状态、硬盘剩余空间、查询语句性能、日志文件大小等；对于应用系统，性能调整主要包括应用系统的可用性、响应时间、并发用户数，以及特定应用的系统资源占用等。","multi":0,"questionType":1,"answer":"D","chooseItem":["794930065300279297"],"itemList":[{"id":"794930065254141953","questionId":"794930063404453889","content":"数据丢包率","answer":0,"chooseValue":"A"},{"id":"794930065270919169","questionId":"794930063404453889","content":"端口吞吐量","answer":0,"chooseValue":"B"},{"id":"794930065283502081","questionId":"794930063404453889","content":"数据处理速率","answer":0,"chooseValue":"C"},{"id":"794930065300279297","questionId":"794930063404453889","content":"查询语句性能","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929998996721665","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">以下关于</span></span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">RISC</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">和</span></span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">CISC</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">的叙述中，不正确的是</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\">①指令系统：</span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">RISC</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">设计者把主要精力放在那些经常使用的指令上，尽量使它们具有简单高效的特色。对不常用的功能，常通过组合指令来完成。而</span></span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">CISC</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机的指令系统比较丰富，有专用指令来完成特定的功能。因此，处理特殊任务效率较高。</span></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">②存储器操作：</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">RISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">对存储器操作有限制，使控制简单化；而</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">CISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">机器的存储器操作指令多，操作直接。</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">③程序：</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">RISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">汇编语言程序一般需要较大的内存空间，实现特殊功能时程序复杂，不易设计；而</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">CISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">汇编语言程序编程相对简单，科学计算及复杂操作的程序社设计相对容易，效率较高。</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">④设计周期：</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">RISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">微处理器结构简单，布局紧凑，设计周期短，且易于采用最新技术；</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">CISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">微处理器结构复杂，设计周期长。</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">⑤应用范围：由于</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">RISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">指令系统的确定与特定的应用领域有关，故</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">RISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">机器更适合于专用机；而</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">CISC</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">机器则更适合于通用机。</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">A</span><span style=\"mso-spacerun:'yes';font-family:Courier;mso-fareast-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930000854798337"],"itemList":[{"id":"794930000854798337","questionId":"794929998996721665","content":"RISC通常比CISC的指令系统更复杂","answer":1,"chooseValue":"A"},{"id":"794930000871575553","questionId":"794929998996721665","content":"RISC通常会比CISC配置更多的寄存器","answer":0,"chooseValue":"B"},{"id":"794930000888352769","questionId":"794929998996721665","content":"RISC编译器的子程序库通常要比CISC编译器的子程序库大得多","answer":0,"chooseValue":"C"},{"id":"794930000909324289","questionId":"794929998996721665","content":"RISC比CISC更加适合VLSI工艺的规整性要求","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930214214848513","title":"声卡中常采用Wave音效合成和MIDI音效合成来播放声音，其中MIDI音效合成有（ ）两种方式。","analyze":"<p>个人计算机中的数字声音有两种不同的表示方法。一种称为波形声音（Wave 音效合成），通过对实际声音的波形信号近似数字化而获得，它能高保直地表示现实世界中任</p><p>何客观存在的真实声音。另外一一种是合成声音，它使用符号对声音进行近似描述，然后通过合成的方法生成声音，常用的是 MIDI音乐。</p><p>声卡中的MIDI音效合成通常采用以下两种方式。</p><p>数字调频合成器（FM）∶FM 是使高频震荡波的频率按调制信号规律变化的一种调制方式。</p><p>PCM波表（形）合成器∶这种方法把真实乐器发出的声音以数字的形式记录下来，将它们存储在波表中，合成音乐时以查表匹配方式获取真实乐器波形。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930216085508097"],"itemList":[{"id":"794930216085508097","questionId":"794930214214848513","content":"FM（调频）和Wave Table（波表）","answer":1,"chooseValue":"A"},{"id":"794930216102285313","questionId":"794930214214848513","content":"FM（调频）和 AM（调幅）","answer":0,"chooseValue":"B"},{"id":"794930216119062529","questionId":"794930214214848513","content":"FM（调频）和功率放大","answer":0,"chooseValue":"C"},{"id":"794930216135839745","questionId":"794930214214848513","content":"AM（调幅）和Wave Table（波表）","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930119809454081","title":"计算机系统中主机与外设间的输入输出控制方式有多种，其中占用主机CPU时间最多的是（）方式。 ","analyze":"<p>程序查询方式是主机通过程序直接控制输入输出设备的工作，此方式下进行主机和外设间的数据交换时，主机CPU要不 断查询外设状态、控制数据传送过程而不进行其他操作。 在中断方式下，主机向输入输出设备发出数据传送的命令后，仍可以进行其他操作， 外设在完成发送或接收数据的准备 工作后，向主机发出中断请求，进行数据传送。在此方式下，外设的准备工作可独立进行，主机在此期间进行其他操 作，但输入输出的数据传送操作仍在主机CPU控制下进行。 在DMA方式下，输入输出设备与内存储器直接相连，数据传送由DMA控制器而不是主机CPU控制。CPU除了传送开始 和终了时进行必要的处理外，不参与数据传送的过程。</p><p>输入输出通道实际上是一种专用处理机。进行输入输出操作时，通道取出并执行保存在主机主存储器中的程序，控制输 入输出设备与主存储器之间的数据交换。这种方式下CPU只需进行少量的处理就实现了并行操作。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930121738833921"],"itemList":[{"id":"794930121692696577","questionId":"794930119809454081","content":"通道方式","answer":0,"chooseValue":"A"},{"id":"794930121713668097","questionId":"794930119809454081","content":"DMA","answer":0,"chooseValue":"B"},{"id":"794930121726251009","questionId":"794930119809454081","content":"中断","answer":0,"chooseValue":"C"},{"id":"794930121738833921","questionId":"794930119809454081","content":"程序查询","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930128684601345","title":"现有4级指令流水线，分别完成取指、取数、运算、传送结果4步操作。若完成上述操作的时间依次为9ns，10ns，6ns和8ns，则流水线的操作周期应设计为 （1） ns。","analyze":"由流水线技术的基本特征可知，其平均时间取决于流水线中最慢的操作，所以流水线的操作周期应设计为时间最长的步骤的时间。","multi":0,"questionType":1,"answer":"D","chooseItem":["794930130584621057"],"itemList":[{"id":"794930130534289409","questionId":"794930128684601345","content":"6","answer":0,"chooseValue":"A"},{"id":"794930130551066625","questionId":"794930128684601345","content":"8","answer":0,"chooseValue":"B"},{"id":"794930130567843841","questionId":"794930128684601345","content":"9","answer":0,"chooseValue":"C"},{"id":"794930130584621057","questionId":"794930128684601345","content":"10","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929905379856385","title":"<p><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">当用户开机按下</span>PC机电源开关对，</span><span style=\"font-family:宋体\">每当开机时自动执行</span><span style=\"font-family: 宋体; font-size: 10.5pt;\">BIOS引导程序</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">，然后加载</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>47）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">BIOS引导程序是固化在ROM芯片上的，每当开机时自动执行BIOS引导程序。它主要执行如下任务：</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•标识和配置所有的即插即用设备。如果系统有即插即用设备的BIOS，系统将搜索和测试所有安装的即插即用设备，并为它们分配DMA通道、IRQ及它们需要的其他设备。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•完成加电自检(POST)。加电自检主要检测和测试内存、端口、键盘、视频适配器、磁盘驱动器等基本设备。有一些新版本的系统还支持CD-ROM驱动器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•对引导驱动器可引导分区定位。在CMOS中，用户可以设置系统的引导顺序，以便对引导驱动器的可引导分区重新定位。大多数系统的引导顺序是软件驱动，然后是硬件驱动，其次是CD-ROM驱动器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•加载主引导记录及引导驱动器的分区表，执行主引导记录MBR。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">主引导记录在硬盘上找到可引导分区后，将其分区引导记录装入内存，并将控制权交给分区引导记录。由分区引导记录定位根目录，再装入操作系统。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">(47)</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"> D</span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929907292459009"],"itemList":[{"id":"794929907250515969","questionId":"794929905379856385","content":"相关支撑软件，如各种设备驱动程序","answer":0,"chooseValue":"A"},{"id":"794929907263098881","questionId":"794929905379856385","content":"分区引导记录、配置系统，并执行分区引导记录","answer":0,"chooseValue":"B"},{"id":"794929907279876097","questionId":"794929905379856385","content":"操作系统，如WindowsXP、Windows7、UNIX等","answer":0,"chooseValue":"C"},{"id":"794929907292459009","questionId":"794929905379856385","content":"主引导记录和引导驱动器的分区表，并执行主引导记录","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929961281540097","title":"<p><span style=\"font-family: Calibri; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机的存储系统采用分级存储体系的理论依据是</span>__(</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> </span><span style=\"font-family: Calibri; font-size: 10.5pt;\">)__<span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><span style=\"font-family:宋体\">计算机的存储系统采用分级存储体系的理论依据是程序访问的局部性原理。</span><span style=\"font-family: Calibri; font-size: 12pt;\">CPU</span><span style=\"font-family:宋体\">访问存储器时，无论是取指令还是存取数据，所访问的存储单元都趋于聚集在一个较小的连续区域中。局部性分为两种，分别是时间局部性和空间局部性。时间局部性是指如果一个信息项正在被访问，那么在近期它很可能还会被再次访问。程序循环、堆栈等是产生时间局部性的原因。空间局部性是指在最近的将来将用到的信息很可能与现在正在使用的信息在空间地址上是临近的。</span><br/></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">计算机系统中常用的三级存储体系是指</span>cache<span style=\"font-family:宋体\">、主存、辅存，这三个级别容量越来越大，价格越来越低，速度越来越慢。</span></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929963189948417"],"itemList":[{"id":"794929963168976897","questionId":"794929961281540097","content":"存储容量、价格与存取速度间的协调性","answer":0,"chooseValue":"A"},{"id":"794929963189948417","questionId":"794929961281540097","content":"程序访问的局部性","answer":1,"chooseValue":"B"},{"id":"794929963202531329","questionId":"794929961281540097","content":"主存和CPU之间的速度匹配","answer":0,"chooseValue":"C"},{"id":"794929963219308545","questionId":"794929961281540097","content":"程序运行的定时性","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929896873807873","title":"<p><br/></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">某计算机系统采用集中式总线仲裁方式，各个主设备得到总线使用权的机会基本相等，则该系统采用的总线仲裁方式</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>17）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">①菊花链式查询方式 ②计数器定时查询（轮询）方式 ③独立请求方式</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">共享总线上允许有多个主设备和从设备，可能会有多个主设备同时要求使用总线的情况</span>(执行操作都是由主设备发起的(，为了防止总线竞争，共享总线上某一时刻只允许-个主设备使用总线。这就需要总线仲裁。集中式仲裁釆用一个中央总线仲裁器(总线控制器)，由它来决定总线上同时提出使用请求的主设备谁可以获得总线使用权，主要有三种方案：菊花链式查询方式，计数器定时查询(轮询(方式和独立请求方式。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">菊花链式查询方式中，设备的先后连接顺序决定了其优先级。而计数器定时查询</span>(轮询(方式及独立请求方式中，可以做到各个主设备得到总线使用权的机会基本相等。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：（</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">17）</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">B</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929898757050369"],"itemList":[{"id":"794929898744467457","questionId":"794929896873807873","content":"可能是③，不可能是①或②","answer":0,"chooseValue":"A"},{"id":"794929898757050369","questionId":"794929896873807873","content":"可能是②或③，不可能是①","answer":1,"chooseValue":"B"},{"id":"794929898773827585","questionId":"794929896873807873","content":"可能是②，不可能是①或③","answer":0,"chooseValue":"C"},{"id":"794929898794799105","questionId":"794929896873807873","content":"可能是①、②或③","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929944252665857","title":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">某地区仅有甲、乙两个企业为销售同种电子产品竞争市场份额。甲企业有三种策略</span> A<span style=\"font-family:宋体\">、</span><span style=\"font-family:Times New Roman\">B</span><span style=\"font-family:宋体\">、</span><span style=\"font-family:Times New Roman\">C</span><span style=\"font-family:宋体\">，乙企业也有三种策略</span><span style=\"font-family:Times New Roman\">Ⅰ</span><span style=\"font-family:宋体\">、</span><span style=\"font-family:Times New Roman\">Ⅱ</span><span style=\"font-family:宋体\">、</span><span style=\"font-family:Times New Roman\">Ⅲ</span><span style=\"font-family:宋体\">。两企业分别独立地选择各种策略时，预计甲企业将增加的市场份额（百分点）见下表（负值表示乙企业将增加的市场份额）。若两企业都采纳稳妥的保守思想（从最坏处着想，争取最好的结果），则</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: "Times New Roman"; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span></span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: "Times New Roman"; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）</span></span></span><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">。</span></span><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\"><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/f738eb1137fc5aa6169ad644527ccdc4.png?x-oss-process=style/ruankaodaren\"/></span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.0000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">悲观主义准则也称为</span>“最大最小”原则，其决策原则是“小中取大”。决策者依次在决策表中的各个投资方案所对应的各个结果中选择出最小结果，并记录，最后再从这些结果中选出最大者，其所对应的方案就是应该采取的决策方案。</span><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.0000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">应用悲观主义准则进行决策，决策结果为：甲选</span>C<span style=\"font-family:宋体\">。因为</span><span style=\"font-family:Times New Roman\">C</span><span style=\"font-family:宋体\">在最差的情况，增长为</span><span style=\"font-family:Times New Roman\">0%</span><span style=\"font-family:宋体\">，而其它的都</span><span style=\"font-family:Times New Roman\">A</span><span style=\"font-family:宋体\">方案最差情况是降低</span><span style=\"font-family:Times New Roman\">1%</span><span style=\"font-family:宋体\">，</span><span style=\"font-family:Times New Roman\">B</span><span style=\"font-family:宋体\">方案最差降低</span><span style=\"font-family:Times New Roman\">5%</span><span style=\"font-family:宋体\">。</span></span><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">在乙企业决策时，注意一个问题，甲的增长即为乙的损失，所以</span>I<span style=\"font-family:宋体\">方案最多降低</span><span style=\"font-family:Times New Roman\">12%</span><span style=\"font-family:宋体\">，</span><span style=\"font-family:Times New Roman\">Ⅱ</span><span style=\"font-family:宋体\">方案最多降低</span><span style=\"font-family:Times New Roman\">10%</span><span style=\"font-family:宋体\">，</span><span style=\"font-family:Times New Roman\">Ⅲ</span><span style=\"font-family:宋体\">方案最多降低</span><span style=\"font-family:Times New Roman\">5%</span><span style=\"font-family:宋体\">，所以应选</span><span style=\"font-family:Times New Roman\">Ⅲ</span><span style=\"font-family:宋体\">。</span></span><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><span style=\"mso-spacerun:'yes';font-family:'Times New Roman';mso-fareast-font-family:黑体;font-size:10.5000pt;mso-font-kerning:1.0000pt;background:#7F7F7F;mso-shading:#7F7F7F;\"><span style=\"font-family:黑体\">参考答案： </span></span><span style=\"mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:'Times New Roman';mso-hansi-font-family:'Times New Roman';mso-bidi-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\">D</span><span style=\"mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:'Times New Roman';mso-hansi-font-family:'Times New Roman';mso-bidi-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929946211405825"],"itemList":[{"id":"794929946131714049","questionId":"794929944252665857","content":"甲选择策略B，乙选择策略Ⅲ","answer":0,"chooseValue":"A"},{"id":"794929946156879873","questionId":"794929944252665857","content":"甲选择策略A，乙选择策略Ⅱ","answer":0,"chooseValue":"B"},{"id":"794929946182045697","questionId":"794929944252665857","content":"甲选择策略B，乙选择策略Ⅱ","answer":0,"chooseValue":"C"},{"id":"794929946211405825","questionId":"794929944252665857","content":"甲选择策略C，乙选择策略Ⅲ","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929927307677697","title":"<p><span style=\"text-indent: 0pt; font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">流水线技术是通过并行硬件来提高系统性能的常用方法。对于一个</span>k段流水线，假设其各段的执行时间均相等（设为t），输入到流水线中的任务是连续的理想情况下，完成n个连续任务需要的总时间为（58）。</span><br/></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p>","analyze":"<p><span style=\"font-family:宋体\">流水线技术是通过并行硬件来提高系统性能的常用方法，它把一项任务分解为若干可以同时进行的并行工作。在任一时刻，任一任务只占其中一个操作部件，这样就可以实现多项任务的重叠执行。对于一个</span><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 21pt;\">k段流水线，假设其各段的执行时间均相等（设为t)，输入到流水线中的任务是连续的理想情况下，从流水线的输出端看，用k个时钟周期输出第一项任务，其余n-1个时钟周期，每个周期输出一项任务，因此完成n个连续任务需要的总时间为(k+n-l)*t。</span><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:宋体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">58）B </span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929929190920193"],"itemList":[{"id":"794929929174142977","questionId":"794929927307677697","content":"nkt","answer":0,"chooseValue":"A"},{"id":"794929929190920193","questionId":"794929927307677697","content":"(k+n-1)t","answer":1,"chooseValue":"B"},{"id":"794929929211891713","questionId":"794929927307677697","content":"(n-k)kt","answer":0,"chooseValue":"C"},{"id":"794929929224474625","questionId":"794929927307677697","content":"(k+n+1)t","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930021897621505","title":"<p><span style=\"font-family:宋体\">计算机系统的性能一般包括两个大的方面。一个方面是它的（</span><span style=\"font-family: 宋体; font-size: 12pt;\"> ），也就是计算机系统能正常工作的时间，其指标可以是能够持续工作的时间长度，也可以是在一段时间内，能正常工作的时间所占的百分比。</span></p>","analyze":"<p><span style=\"font-family: 宋体; font-size: 12pt;\">计算机系统的性能一般包括两个大的方面。一个方面是它的可靠性或可用性，也就是计算机系统能正常工作的时间，其指标可以是能够持续工作的时间长度（例如，平均无故障时间），也可以是在一段时间内，能正常工作的时间所占的百分比；另一个方面是它的处理能力或效率，这又可分为三类指标，第一类指标是吞吐率（例如，系统在单位时间内能处理正常作业的个数），第二类指标是响应时间（从系统得到输入到给出输出之间的时间），第三类指标是资源利用率，即在给定的时间区间中，各种部件（包括硬设备和软件系统）被使用的时间与整个时间之比。当然，不同的系统对性能指标的描述有所不同，例如，计算机网络系统常用的性能评估指标为信道传输速率、信道吞吐量和容量、信道利用率、传输延迟、响应时间和负载能力等。</span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930023772475393"],"itemList":[{"id":"794930023772475393","questionId":"794930021897621505","content":"可用性","answer":1,"chooseValue":"A"},{"id":"794930023793446913","questionId":"794930021897621505","content":"安全性","answer":0,"chooseValue":"B"},{"id":"794930023814418433","questionId":"794930021897621505","content":"健壮性","answer":0,"chooseValue":"C"},{"id":"794930023835389953","questionId":"794930021897621505","content":"可伸缩性","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930108149288961","title":"<p>三个可靠度R均为0.8的部件串联构成一个系统，如下图所示：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/7f4e82c85298d26200b35583ace0c195.jpg?x-oss-process=style/ruankaodaren\" title=\"7f4e82c85298d26200b35583ace0c195.jpg\" alt=\"1.jpg\"/></p><p>则该系统的可靠度为（）。</p>","analyze":"本题中由三个部件串联构成系统，三个部件中任何一个部件失效就足以使系统失效。串联系统的可靠度RS=R×R×R=0.8×0.8×0.8=0.512。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930110049308673"],"itemList":[{"id":"794930110028337153","questionId":"794930108149288961","content":"0.240","answer":0,"chooseValue":"A"},{"id":"794930110049308673","questionId":"794930108149288961","content":"0.512","answer":1,"chooseValue":"B"},{"id":"794930110066085889","questionId":"794930108149288961","content":"0.800","answer":0,"chooseValue":"C"},{"id":"794930110082863105","questionId":"794930108149288961","content":"0.992","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930211345944577","title":"CPU中的数据总线宽度会影响（ ）。","analyze":"CPU与其他部件交换数据时，用数据总线传输数据。数据总线宽度指同时传送的二进制位数，内存容量、指令系统中的指令数量和寄存器的位数与数据总线的宽度无关。数据总线宽度越大，单位时间内能进出CPU的数据就越多，系统的运算速度越快。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930213241769985"],"itemList":[{"id":"794930213216604161","questionId":"794930211345944577","content":"内存容量的大小","answer":0,"chooseValue":"A"},{"id":"794930213241769985","questionId":"794930211345944577","content":"系统的运算速度","answer":1,"chooseValue":"B"},{"id":"794930213266935809","questionId":"794930211345944577","content":"指令系统的指令数量","answer":0,"chooseValue":"C"},{"id":"794930213287907329","questionId":"794930211345944577","content":"寄存器的宽度","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930202789564417","title":"如果主存容量为16M字节，且按字节编址，表示该主存地址至少应需要（ ）位。 ","analyze":"用二进制编码表示地址，16M=2^24，因此最少需要24位。","multi":0,"questionType":1,"answer":"C","chooseItem":["794930204660224001"],"itemList":[{"id":"794930204618280961","questionId":"794930202789564417","content":"16","answer":0,"chooseValue":"A"},{"id":"794930204639252481","questionId":"794930202789564417","content":"20","answer":0,"chooseValue":"B"},{"id":"794930204660224001","questionId":"794930202789564417","content":"24","answer":1,"chooseValue":"C"},{"id":"794930204677001217","questionId":"794930202789564417","content":"32","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930125698256897","title":"某4级流水线如下图所示，若每3<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/5e197c16ae4f8ea536807e3fe584a09d.jpg?x-oss-process=style/ruankaodaren\" title=\"5e197c16ae4f8ea536807e3fe584a09d.jpg\" alt=\"1.jpg\"/>t向该流水线输入一个任务，连续输入4个，则该流水线的加速比为（）<br/><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/7cf00bb24a8e46c8ef6c0b64edf140fc.jpg?x-oss-process=style/ruankaodaren\" title=\"7cf00bb24a8e46c8ef6c0b64edf140fc.jpg\" alt=\"1.jpg\"/>","analyze":"<p>流水线的加速比定义为：为完成一批任务，不使用流水线所用的时间与使用流水线所用的时间之比称为流水线的速度比。</p><p>由于需要连续执行4次上图的处理过程，因此在不使用流水线时，所需的时间为<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/0d2206e74a595d8b7dfb36f865dbad58.jpg?x-oss-process=style/ruankaodaren\" title=\"0d2206e74a595d8b7dfb36f865dbad58.jpg\" alt=\"1.jpg\"/>，而使用流水</p><p>线所用的时间为<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/ad5ed5fea28f5907a41c99a7c35159e2.jpg?x-oss-process=style/ruankaodaren\" title=\"ad5ed5fea28f5907a41c99a7c35159e2.jpg\" alt=\"1.jpg\"/>，所以，加速比为：<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/a512475e690b9e6210dabf88b9b890c4.jpg?x-oss-process=style/ruankaodaren\" title=\"a512475e690b9e6210dabf88b9b890c4.jpg\" alt=\"2.jpg\"/></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930127677968385"],"itemList":[{"id":"794930127648608257","questionId":"794930125698256897","content":"4","answer":0,"chooseValue":"A"},{"id":"794930127677968385","questionId":"794930125698256897","content":"1.75","answer":1,"chooseValue":"B"},{"id":"794930127711522817","questionId":"794930125698256897","content":"1.5","answer":0,"chooseValue":"C"},{"id":"794930127740882945","questionId":"794930125698256897","content":"1","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929911050555393","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机系统性能评估中，</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>61）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">考虑了诸如</span>I/O结构、操作系统、编译程序的效率对系统性能的影响，可以较为准确评估计算机系统的实际性能。</span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机性能评估方法基本上分为两大类，分别是测量方法和模型方法。测量方法指通过一定的测量设备或测量程序，可以直接从系统中测得各项性能指标或与之密切的相关度量，然后，由它们经过一些简单的运算，求出相应的性能指标。模型方法的基本思想是，首先对要评估的系统建立适当模型，然后求出模型的性能指标，以便对系统进行性能评估。本试题考查的是测量方法中的经典评测方法的基本知识。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">测量方法中经典的性能评估方法有时钟频率法、指令执行速度法、等效指令速度法、数据处理速率法、综合理论性能法等。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">时钟频率法：计算机的时钟频率在一定程度上反映了机器速度，对于同一种机型的计算机，时钟频率越高，计算机的速度就越快，但是不同体系结构的计算机，相同频率下，其速度和性能可能会差别很大。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">指令执行速度法：计算机发展中，由于加法的指令速度大体上可反映出乘法、除法等其他算术运算的速度，而逻辑运算、转移指令等简单指令的执行时间往往设计成与加法指令相同，因此可以采用加法指令的运算速度来衡量计算机的速度。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">等效指令速度法：也称为吉普森或混合比例计算法，是通过各类指令在程序中所占的比例进行计算后得到的计算机运算速度。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">数据处理速率法</span>(ProcessingDataRate，PDR)：采用计算PDR值的方法来衡量机器性能，PDR值越大，机器性能越好。PDR与每条指令和每个操作数的平均位数以及每条指令的平均运算速度有关。PDR主要对CPU和主存储器的速度进行度量，不适合衡量机器的整体速度，不能全面反映计算机的性能，因为它没有涉及Cache、多功能部件等技术对性能的影响。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">综合理论性能法：该方法是首先计算出处理部件每个计算单元的有效计算率，再按不同字长加以调整，得出该计算单元的理论性能，所有组成该处理部件的计算单元的理论性能之和即为最终的计算机性能。<br/><br/> 基准程序法：把应用程序中用得最多、最频繁的那部分核心程序作为评估计算机系统性能的标准程序，称为基准测试程序（benchmark）。基准程序法是目前一致承认的测试系统性能的较好方法。<br/><br/></span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案:</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">(61) D</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> </span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929913059627009"],"itemList":[{"id":"794929912963158017","questionId":"794929911050555393","content":"时钟频率法","answer":0,"chooseValue":"A"},{"id":"794929913000906753","questionId":"794929911050555393","content":"等效指令速度法","answer":0,"chooseValue":"B"},{"id":"794929913030266881","questionId":"794929911050555393","content":"综合理论性能法","answer":0,"chooseValue":"C"},{"id":"794929913059627009","questionId":"794929911050555393","content":"基准程序法","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930250940174337","title":"<p>流水线的吞吐率是指流水线在单位时间里所完成的任务数或输出的结果数。设某流水线有5段，有1段的时间为2 n s，另外4段的每段时间为l n s，利用此流水线完成10个任务的吞吐率约为 （12） 个/s。</p>","analyze":"<p>10个任务所需要的时间为：</p><p>(2+1+1+1+1)+(10–1)*2=24（ns）</p><p>由于<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/137ff0c3223f5ce40f4416f310318494.png?x-oss-process=style/ruankaodaren\" title=\"137ff0c3223f5ce40f4416f310318494.png\" alt=\"image.png\" width=\"94\" height=\"25\"/>，所以每秒吞吐率为：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/f778e807eb5ce908b39ffe46eee51bae.png?x-oss-process=style/ruankaodaren\" title=\"f778e807eb5ce908b39ffe46eee51bae.png\" alt=\"image.png\"/><br/></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930252827611137"],"itemList":[{"id":"794930252798251009","questionId":"794930250940174337","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/1912dc19314263895c281144931d234d.png?x-oss-process=style/ruankaodaren\" title=\"1912dc19314263895c281144931d234d.png\" alt=\"image.png\"/>","answer":0,"chooseValue":"A"},{"id":"794930252810833921","questionId":"794930250940174337","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/ef677787edbe113f2d3f501e9e681fd2.png?x-oss-process=style/ruankaodaren\" title=\"ef677787edbe113f2d3f501e9e681fd2.png\" alt=\"image.png\"/>","answer":0,"chooseValue":"B"},{"id":"794930252827611137","questionId":"794930250940174337","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/c9615f32d42c1b9f3ea2899fde7eedac.png?x-oss-process=style/ruankaodaren\" title=\"c9615f32d42c1b9f3ea2899fde7eedac.png\" alt=\"image.png\"/>","answer":1,"chooseValue":"C"},{"id":"794930252844388353","questionId":"794930250940174337","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/94874ac81d2e2b66689e2341fa72adcb.png?x-oss-process=style/ruankaodaren\" title=\"94874ac81d2e2b66689e2341fa72adcb.png\" alt=\"image.png\"/>","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930259546886145","title":"JTAG是用来进行嵌入式处理器调试的标准化接口，下列描述中，正确的是（）。","analyze":"<p>本题考查嵌入式系统调试时候采用的JTAG方面的基础知识。</p><p>JTAG (Joint Test Action Group，联合测试工作组)是一种国际标准测试协议(IEEE 1149.1兼容)，主要用于芯片内部测试。现在多数的高级器件都支持JTAG协议，如DSP、FPGA器件等。标准的JTAG接口是4线：TMS、TCK、TDI、TDO，分别为模式选择、时钟、数据输入和数据输出线，有时还包含复位等信号。</p><p>JTAG最初是用来对芯片进行测试的，JTAG的基本原理是在器件内部定义一个TAP (Test Access Port，测试访问口)通过专用的JTAG测试工具对内部节点进行测试。JTAG测试允许多个器件通过JTAG接口串联在一起，形成一个JTAG链，能实现对各个器件分别测试。</p><p>当JTAG上面的时钟不正常时，访问CPU内部的寄存器时可能出现异常，JTAG可以用于多种功能，包括软件调试，系统芯片检测，除了可以访问CPU内部寄存器外，还可以访问CPU总线上面的设备状态等。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930261396574209"],"itemList":[{"id":"794930261396574209","questionId":"794930259546886145","content":"JTAG接口上一般包括模式选择、时钟、数据输入、数据输出、复位等信号","answer":1,"chooseValue":"A"},{"id":"794930261413351425","questionId":"794930259546886145","content":"当JTAG接口上面的时钟不正常时，也可以访问CPU内部的寄存器","answer":0,"chooseValue":"B"},{"id":"794930261434322945","questionId":"794930259546886145","content":"JTAG只能用于调试，而不能用于进行芯片问题的检测","answer":0,"chooseValue":"C"},{"id":"794930261446905857","questionId":"794930259546886145","content":"JTAG能够访问CPU内部的寄存器，而不能访问CPU总线上面的设备","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930019045494785","title":"<p><span style=\"font-family:宋体\">以下关于信息属性的描述，错误的是（</span><span style=\"font-family: 宋体; font-size: 12pt;\"> ）。</span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 12pt;\"><span style=\"font-family:宋体\">本题主要考查考生对信息这一概念的理解。信息是反应客观世界中各种事物特征和变化的知识，是数据加工的结果，信息是有用的数据。信息具有存在的普遍性；载体依附性；有序性；相对性；可度量性；可扩充性；可压缩性；可存储、传输与携带性；可替代性；可扩散性；可共享性；时效性等重要性质。</span> <span style=\"font-family:宋体\">信息具有真伪性，真实是信息的中心价值，不真实的信息价值可能为负。</span> <span style=\"font-family:宋体\">信息具有滞后性，信息是数据加工的结果，因此信息必然落后于数据，加工需要时间。</span> <span style=\"font-family:宋体\">信息的时效性是指信息的效用依赖于时间并有一定的期限，其价值的大小与提供信息的时间密切相关。实践证明，信息一经形成，所提供的速度越快，时间越早，其实现价值越大。</span> <span style=\"font-family:宋体\">信息的共享性是指信息作为一种资源，不同个体或群体在同一时间或不同时间均可使用这种资源。</span> <span style=\"font-family:宋体\">信息具有扩压性，信息和实物不同，它可以扩散也可以压缩。</span></span><span style=\"font-family: Calibri; font-size: 10.5pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">试题答案</span></span></strong><span style=\"font-family: 宋体; font-size: 12pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930020953903105"],"itemList":[{"id":"794930020899377153","questionId":"794930019045494785","content":"信息具有真伪性，真实是信息的中心价值，不真实的信息价值可能为负","answer":0,"chooseValue":"A"},{"id":"794930020920348673","questionId":"794930019045494785","content":"信息具有滞后性，信息是数据加工的结果，因此信息必然落后于数据，加工需要时间","answer":0,"chooseValue":"B"},{"id":"794930020937125889","questionId":"794930019045494785","content":"信息具有扩压性，信息和实物不同，它可以扩散也可以压缩","answer":0,"chooseValue":"C"},{"id":"794930020953903105","questionId":"794930019045494785","content":"信息具有完全性，我们能够获取客观真实的全部信息，从而进行判断","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930074896846849","title":"在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式（包括无条件传送与程序查询方式）、程序中断方式、DMA工作方式、通道方式、I/O处理机。（请作答此空）方式I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，并且只适用于简单的I/O控制。（ ）允许主存储器和I/O设备之间通过某种控制器直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。 （ ）在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入。（ ）指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。上述工作方式中，（）工作方式CPU与I/O设备是串行工作的。","analyze":"<p>在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式、程序中断方式、DMA工作方式、通道方式、I/O处理机。</p><p>1、程序控制方式</p><p>分为无条件查询和程序查询方式。</p><p> ① 无条件传送方式，I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，而cpu在需要时，随时直接利用I/O指令访问相应的I/O端口，实现与外设的数据交换。优点是软、硬件结构简单，缺点是对时序要求高，只适用于简单的I/O控制。</p><p>② 程序查询方式</p><p>程序查询方式也称为程序轮询方式，该方式采用用户程序直接控制主机与外部设备之间输入/输出操作。CPU必须不停地循环测试I/O设备的状态端口，当发现设备处于准备好(Ready)状态时，CPU就可以与I/O设备进行数据存取操作。这种方式下的CPU与I/O设备是串行工作的。</p><p>2、中断方式</p><p>当I/O设备结束(完成、特殊或异常)时，就会向CPU发出中断请求信号，CPU收到信号就可以采取相应措施。当某个进程要启动某个设备时，CPU就向相应的设备控制器发出一条设备I/O启动指令，然后CPU又返回做原来的工作。CPU与I/O设备可以并行工作，与程序查询方式相比，大大提高了CPU的利用率。</p><p>3、DMA(直接内存存取)方式</p><p>DMA方式也称为直接主存存取方式，其思想是：允许主存储器和I/O设备之间通过“DMA控制器(DMAC)”直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。</p><p>4、通道控制方式</p><p>在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入，使主机和外设并行工作程度更高。</p><p>5、I/O处理机</p><p>指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930076809449473"],"itemList":[{"id":"794930076775895041","questionId":"794930074896846849","content":"中断方式","answer":0,"chooseValue":"A"},{"id":"794930076792672257","questionId":"794930074896846849","content":"I/O处理机","answer":0,"chooseValue":"B"},{"id":"794930076809449473","questionId":"794930074896846849","content":"无条件传送","answer":1,"chooseValue":"C"},{"id":"794930076830420993","questionId":"794930074896846849","content":"程序查询","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930027673178113","title":"<p><span style=\"font-family:宋体\">（</span><span style=\"font-family: Calibri; font-size: 12pt;\"> </span><span style=\"font-family:宋体\">）标准的目标是制定一个开放的多媒体应用框架标准。</span><br/></p><p class=\"MsoNormal\" style=\"margin-bottom: 12pt;\"><br/></p><p class=\"p\"><br/></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">本题考查考生对各种多媒体相关的国际标准的了解情况。</span>H.264<span style=\"font-family:宋体\">是国际电信联盟（</span><span style=\"font-family:Calibri\">ITU</span><span style=\"font-family:宋体\">）制定的视频信号和音频信号的压缩编码标准：</span><span style=\"font-family:Calibri\">X3D</span><span style=\"font-family:宋体\">是由</span><span style=\"font-family:Calibri\">Web3D</span><span style=\"font-family:宋体\">联盟专为</span><span style=\"font-family:Calibri\">Internet</span><span style=\"font-family:宋体\">应用设计的三维图形标记语言，是</span><span style=\"font-family:Calibri\">VRML</span><span style=\"font-family:宋体\">标准的升级版本；</span><span style=\"font-family:Calibri\">MPEG-21</span><span style=\"font-family:宋体\">是</span><span style=\"font-family:Calibri\">ISO/IEC</span><span style=\"font-family:宋体\">制定为一个标准，致力于定义多媒体应用的一个开放框架。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">试题答案</span></span></strong><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span><span style=\"font-family: 宋体; font-size: 12pt;\">B</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930029535449089"],"itemList":[{"id":"794930029518671873","questionId":"794930027673178113","content":"H.264","answer":0,"chooseValue":"A"},{"id":"794930029535449089","questionId":"794930027673178113","content":"MPEG-21","answer":1,"chooseValue":"B"},{"id":"794930029552226305","questionId":"794930027673178113","content":"XML","answer":0,"chooseValue":"C"},{"id":"794930029569003521","questionId":"794930027673178113","content":"X3D","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929993380548609","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">属于</span></span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">CPU</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">中算术逻辑单元的部件是在</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">算术逻辑运算单元</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">ALU(Arithmetic and Logic Unit)ALU</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">主要完成对二进制数据的定点算术运算</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">(</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">加减乘除</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">、逻辑运算</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">(</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">与或非异或</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">以及移位操作。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">B</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929995247013889"],"itemList":[{"id":"794929995230236673","questionId":"794929993380548609","content":"程序计数器","answer":0,"chooseValue":"A"},{"id":"794929995247013889","questionId":"794929993380548609","content":"加法器","answer":1,"chooseValue":"B"},{"id":"794929995267985409","questionId":"794929993380548609","content":"指令寄存器","answer":0,"chooseValue":"C"},{"id":"794929995288956929","questionId":"794929993380548609","content":"指令译码器","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930113874513921","title":"CPU中的数据总线宽度会影响（）。","analyze":"CPU与其他部件交换数据时，用数据总线传输数据。数据总线宽度指同时传送的二进制位数，内存容量、指令系统中的指令数量和寄存器的位数与数据总线的宽度无关。数据总线宽度越大，单位时间内能进出CPU的数据就越多，系统的运算速度越快。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930115854225409"],"itemList":[{"id":"794930115837448193","questionId":"794930113874513921","content":"内存容量的大小","answer":0,"chooseValue":"A"},{"id":"794930115854225409","questionId":"794930113874513921","content":"系统的运算速度","answer":1,"chooseValue":"B"},{"id":"794930115866808321","questionId":"794930113874513921","content":"指令系统的指令数量","answer":0,"chooseValue":"C"},{"id":"794930115879391233","questionId":"794930113874513921","content":"寄存器的宽度","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930225543663617","title":"<p>属于CPU中算术逻辑单元的部件是在（）。</p>","analyze":"<p>算术逻辑运算单元ALU(Arithmetic and Logic Unit)ALU主要完成对二进制数据的定点算术运算(加减乘除)、逻辑运算(与或非异或)以及移位操作。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930227435294721"],"itemList":[{"id":"794930227418517505","questionId":"794930225543663617","content":"程序计数器","answer":0,"chooseValue":"A"},{"id":"794930227435294721","questionId":"794930225543663617","content":"加法器","answer":1,"chooseValue":"B"},{"id":"794930227460460545","questionId":"794930225543663617","content":"指令寄存器","answer":0,"chooseValue":"C"},{"id":"794930227481432065","questionId":"794930225543663617","content":"指令译码器","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930165514784769","title":"<p>若某计算机是由四个部件并串联构成，如下图所示。且每一部件的可靠度R都是0.9，则该计算机的可靠度为（13）。</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/425d0a6154a72014ffe6670c0cf74f51.jpg?x-oss-process=style/ruankaodaren\" title=\"425d0a6154a72014ffe6670c0cf74f51.jpg\" alt=\"1.jpg\"/></p><br/>","analyze":"并联系统的可靠度是0.99，串联的可靠度是0.98。","multi":0,"questionType":1,"answer":"A","chooseItem":["794930167368667137"],"itemList":[{"id":"794930167368667137","questionId":"794930165514784769","content":"0.980","answer":1,"chooseValue":"A"},{"id":"794930167393832961","questionId":"794930165514784769","content":"0.990","answer":0,"chooseValue":"B"},{"id":"794930167423193089","questionId":"794930165514784769","content":"0.995","answer":0,"chooseValue":"C"},{"id":"794930167448358913","questionId":"794930165514784769","content":"0.999","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930199975186433","title":"<p>前趋图(Precedence Graph) 是一个有向无环图,记为:→={(Pi,Pj)|Pi must complete before Pj may strat}，假设系统中进程P={P1，P2，P3，P4，P5，P6，P7，P8}，且进程的前趋图如下：<br/><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/bccc3cb85696acf1a8fd30d54e4f3194.jpg?x-oss-process=style/ruankaodaren\" title=\"bccc3cb85696acf1a8fd30d54e4f3194.jpg\" alt=\"1.jpg\"/></p>","analyze":"(Pi，Pj)表示前趋图的一个进程之间的逻辑关系，该图一共有12个逻辑关系。记为→={（P1，P2），（P1，P3），（P2，P3），（P2，P5），（P3，P4），（P3，P5），（P4，P6），（P5，P6），（P5，P7），（P5，P8），（P6，P8），（P7，P8）}","multi":0,"questionType":1,"answer":"C","chooseItem":["794930201854234625"],"itemList":[{"id":"794930201820680193","questionId":"794930199975186433","content":"→={（P1，P2），（P3，P1），（P4，P1），（P5，P2），（P5，P3），（P6，P4），（P7，P5），（P7，P6），（P5，P6），（P4，P5），（P6，P7），（P7，P6）}","answer":0,"chooseValue":"A"},{"id":"794930201837457409","questionId":"794930199975186433","content":"→={（P1，P2），（P1，P3），（P2，P5），（P2，P3），（P3，P4），（P3，P5），（P4，P5），（P5，P6），（P5，P7），（P8，P5），（P6，P7），（P7，P8）}","answer":0,"chooseValue":"B"},{"id":"794930201854234625","questionId":"794930199975186433","content":"→={（P1，P2），（P1，P3），（P2，P3），（P2，P5），（P3，P4），（P3，P5），（P4，P6），（P5，P6），（P5，P7），（P5，P8），（P6，P8），（P7，P8）}","answer":1,"chooseValue":"C"},{"id":"794930201866817537","questionId":"794930199975186433","content":"→={（P1，P2），（P1，P3），（P2，P3），（P2，P5），（P3，P6），（P3，P4），（P4，P7），（P5，P6），（P6，P7），（P6，P5），（P7，P5），（P7，P8）}","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929908202622977","title":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机系统性能评估中，</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>60）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">考虑了各类指令在程序中所占的比例。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">计算机性能评估方法基本上分为两大类，分别是测量方法和模型方法。测量方法指通过一定的测量设备或测量程序，可以直接从系统中测得各项性能指标或与之密切的相关度量，然后，由它们经过一些简单的运算，求出相应的性能指标。模型方法的基本思想是，首先对要评估的系统建立适当模型，然后求出模型的性能指标，以便对系统进行性能评估。本试题考查的是测量方法中的经典评测方法的基本知识。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">测量方法中经典的性能评估方法有时钟频率法、指令执行速度法、等效指令速度法、数据处理速率法、综合理论性能法等。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">时钟频率法：计算机的时钟频率在一定程度上反映了机器速度，对于同一种机型的计算机，时钟频率越高，计算机的速度就越快，但是不同体系结构的计算机，相同频率下，其速度和性能可能会差别很大。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">指令执行速度法：计算机发展中，由于加法的指令速度大体上可反映出乘法、除法等其他算术运算的速度，而逻辑运算、转移指令等简单指令的执行时间往往设计成与加法指令相同，因此可以采用加法指令的运算速度来衡量计算机的速度。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">等效指令速度法：也称为吉普森或混合比例计算法，是通过各类指令在程序中所占的比例进行计算后得到的计算机运算速度。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">数据处理速率法</span>(ProcessingDataRate，PDR)：采用计算PDR值的方法来衡量机器性能，PDR值越大，机器性能越好。PDR与每条指令和每个操作数的平均位数以及每条指令的平均运算速度有关。PDR主要对CPU和主存储器的速度进行度量，不适合衡量机器的整体速度，不能全面反映计算机的性能，因为它没有涉及Cache、多功能部件等技术对性能的影响。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">综合理论性能法：该方法是首先计算出处理部件每个计算单元的有效计算率，再按不同字长加以调整，得出该计算单元的理论性能，所有组成该处理部件的计算单元的理论性能之和即为最终的计算机性能。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">(60)B</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"> </span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929910085865473"],"itemList":[{"id":"794929910069088257","questionId":"794929908202622977","content":"时钟频率法","answer":0,"chooseValue":"A"},{"id":"794929910085865473","questionId":"794929908202622977","content":"等效指令速度法","answer":1,"chooseValue":"B"},{"id":"794929910102642689","questionId":"794929908202622977","content":"综合理论性能法","answer":0,"chooseValue":"C"},{"id":"794929910123614209","questionId":"794929908202622977","content":"基准程序法","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929947125764097","title":"<p><br/></p><p class=\"MsoNormal\" style=\"margin-left:0.0000pt;mso-para-margin-left:0.0000gd;text-indent:24.0000pt;mso-char-indent-count:2.0000;\"><span style=\"mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">在程序执行过程中，</span>Cache <span style=\"font-family:宋体\">与主存的地址映射是由（ </span></span><span style=\"mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">）完成的。</span></span><span style=\"mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\"><br/></p><p class=\"MsoNormal\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">Cache<span style=\"font-family:宋体\">与主存之间的映射由硬件实现，主存与辅存之间的交互是硬件与软件结合起来实现的。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">C</span></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794929949076115457"],"itemList":[{"id":"794929949017395201","questionId":"794929947125764097","content":"操作系统","answer":0,"chooseValue":"A"},{"id":"794929949050949633","questionId":"794929947125764097","content":"程序员调度","answer":0,"chooseValue":"B"},{"id":"794929949076115457","questionId":"794929947125764097","content":"硬件自动","answer":1,"chooseValue":"C"},{"id":"794929949101281281","questionId":"794929947125764097","content":"用户软件","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929938602938369","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"><span style=\"font-family:宋体\">以下压缩音频编码方法，（</span>62）编码使用了心理声学模型，从而实现了高效率的数字音频压缩。</span></p>","analyze":"<p><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 21pt;\">PCM通过抽样、量化、编码三个步骤将连续变化的模拟信号转换为数字编码。</span><br/></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 21pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">ADPCM编码在PCM脉冲编码调制的基础上引入了 “自适应”的思想。“自适应”是指根据输入信号幅度大小自动地改变量化阶的大小。</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 21pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">LPC是根据过去已有的几个采样值的模型的线性组合来推断现在的采样值，进而用实际采样值与预测采样值之差（预测误差）及线性预测系数进行编码。</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 20.7pt; line-height: 150%;\"><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\">MPEG音频编码方法使用了心理声学模型。</span><span style=\"mso-spacerun:'yes';font-family:宋体;line-height:150%;font-size:10.5000pt;mso-font-kerning:1.0000pt;\"></span></p><p class=\"MsoNormal\" style=\"margin-left: 0pt; text-indent: 0pt; line-height: 150%;\"><span style=\"font-family: 宋体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:宋体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">62）B </span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929940486180865"],"itemList":[{"id":"794929940473597953","questionId":"794929938602938369","content":"PCM","answer":0,"chooseValue":"A"},{"id":"794929940486180865","questionId":"794929938602938369","content":"MPEG音频","answer":1,"chooseValue":"B"},{"id":"794929940502958081","questionId":"794929938602938369","content":"ADPCM","answer":0,"chooseValue":"C"},{"id":"794929940519735297","questionId":"794929938602938369","content":"LPC","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930080605294593","title":"在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式（包括无条件传送与程序查询方式）、程序中断方式、DMA工作方式、通道方式、I/O处理机。（）方式I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，并且只适用于简单的I/O控制。（）允许主存储器和I/O设备之间通过某种控制器直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。 （请作答此空）在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入。（ ）指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。上述工作方式中，（ ）工作方式CPU与I/O设备是串行工作的。","analyze":"<p>在计算机中，I/O系统可以有5种不同的工作方式，分别是程序控制方式、程序中断方式、DMA工作方式、通道方式、I/O处理机。</p><p>1、程序控制方式</p><p>分为无条件查询和程序查询方式。</p><p> ① 无条件传送方式，I/O端口总是准备好接受主机的输出数据，或是总是准备好向主机输入数据，而cpu在需要时，随时直接利用I/O指令访问相应的I/O端口，实现与外设的数据交换。优点是软、硬件结构简单，缺点是对时序要求高，只适用于简单的I/O控制。</p><p>② 程序查询方式</p><p>程序查询方式也称为程序轮询方式，该方式采用用户程序直接控制主机与外部设备之间输入/输出操作。CPU必须不停地循环测试I/O设备的状态端口，当发现设备处于准备好(Ready)状态时，CPU就可以与I/O设备进行数据存取操作。这种方式下的CPU与I/O设备是串行工作的。</p><p>2、中断方式</p><p>当I/O设备结束(完成、特殊或异常)时，就会向CPU发出中断请求信号，CPU收到信号就可以采取相应措施。当某个进程要启动某个设备时，CPU就向相应的设备控制器发出一条设备I/O启动指令，然后CPU又返回做原来的工作。CPU与I/O设备可以并行工作，与程序查询方式相比，大大提高了CPU的利用率。</p><p>3、DMA(直接内存存取)方式</p><p>DMA方式也称为直接主存存取方式，其思想是：允许主存储器和I/O设备之间通过“DMA控制器(DMAC)”直接进行批量数据交换，除了在数据传输开始和结束时，整个过程无须CPU的干预。</p><p>4、通道控制方式</p><p>在一定的硬件基础上利用软件手段实现对I/O的控制和传送，更多地免去了cpu的接入，使主机和外设并行工作程度更高。</p><p>5、I/O处理机</p><p>指专门负责输入/输出的处理机。可以有独立的存储器、运算部件和指令控制部件。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930082496925697"],"itemList":[{"id":"794930082467565569","questionId":"794930080605294593","content":"I/O处理机","answer":0,"chooseValue":"A"},{"id":"794930082484342785","questionId":"794930080605294593","content":"DMA方式","answer":0,"chooseValue":"B"},{"id":"794930082496925697","questionId":"794930080605294593","content":"通道控制方式","answer":1,"chooseValue":"C"},{"id":"794930082513702913","questionId":"794930080605294593","content":"程序查询","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930016214339585","title":"<p><span style=\"font-family: 宋体; font-size: 10.5pt; text-indent: 20.7pt;\">C</span><span style=\"font-family:宋体\">程序中全局变量的存储空间在（</span><span style=\"font-family:Calibri\"> </span><span style=\"font-family:宋体\">）分配。</span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">本题考查程序设计语言内存分配知识点。一个由</span>c/c++<span style=\"font-family:宋体\">编译的程序占用的内存分为以下几个部分：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">1.<span style=\"font-family:宋体\">栈区（</span><span style=\"font-family:Calibri\">stack</span><span style=\"font-family:宋体\">）：由编译器自动分配释放，存放函数的参数值，局部变量的值等。其操作方式类似于数据结构中的栈。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">2.<span style=\"font-family:宋体\">堆区（</span><span style=\"font-family:Calibri\">heap</span><span style=\"font-family:宋体\">）：一般由程序员分配释放，若程序员不释放，程序结束时可能由</span><span style=\"font-family:Calibri\">OS</span><span style=\"font-family:宋体\">回收。注意它与数据结构中的堆是两回事，链表的数据空间必须采用堆存储分配策略。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">3.<span style=\"font-family:宋体\">全局区（静态区）（</span><span style=\"font-family:Calibri\">static</span><span style=\"font-family:宋体\">）：全局变量和静态变量的存储是放在这一块的。初始化的全局变量和静态变量在一块区域，未初始化的全局变量和未初始化的静态变量在相邻的另一块区域，程序结束后由系统释放。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">4.<span style=\"font-family:宋体\">文字常量区：常量字符串就是放在这里的，程序结束后由系统释放。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">5.<span style=\"font-family:宋体\">程序代码区：存放函数体的二进制代码。</span></span><span style=\"font-family: Calibri; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span><span style=\"font-family:Calibri\">B</span></span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930018084999169"],"itemList":[{"id":"794930018068221953","questionId":"794930016214339585","content":"代码区","answer":0,"chooseValue":"A"},{"id":"794930018084999169","questionId":"794930016214339585","content":"静态数据区","answer":1,"chooseValue":"B"},{"id":"794930018101776385","questionId":"794930016214339585","content":"栈区","answer":0,"chooseValue":"C"},{"id":"794930018118553601","questionId":"794930016214339585","content":"堆区","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930024837828609","title":"<p><span style=\"font-family: 宋体; font-size: 12pt;\">计算机系统的性能一般包括两个大的方面，</span><span style=\"font-family:宋体\">一个方面是处理能力，这又可分为三类指标，第一类指标是吞吐率，第二类指标是响应时间，第三类指标是（</span><span style=\"font-family: 宋体; font-size: 12pt;\"> ），即在给定时间区间中，各种部件被使用的时间与整个时间之比。</span><br/></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><br/></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\"><span style=\"mso-spacerun:'yes';font-family:宋体;font-size:12.0000pt;mso-font-kerning:0.0000pt;\">计算机系统的性能一般包括两个大的方面。一个方面是它的可靠性或可用性，也就是计算机系统能正常工作的时间，其指标可以是能够持续工作的时间长度（例如，平均无故障时间），也可以是在一段时间内，能正常工作的时间所占的百分比；另一个方面是它的处理能力或效率，这又可分为三类指标，第一类指标是吞吐率（例如，系统在单位时间内能处理正常作业的个数），第二类指标是响应时间（从系统得到输入到给出输出之间的时间），第三类指标是资源利用率，即在给定的时间区间中，各种部件（包括硬设备和软件系统）被使用的时间与整个时间之比。当然，不同的系统对性能指标的描述有所不同，例如，计算机网络系统常用的性能评估指标为信道传输速率、信道吞吐量和容量、信道利用率、传输延迟、响应时间和负载能力等。</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930026716876801"],"itemList":[{"id":"794930026695905281","questionId":"794930024837828609","content":"可靠性","answer":0,"chooseValue":"A"},{"id":"794930026716876801","questionId":"794930024837828609","content":"资源利用率","answer":1,"chooseValue":"B"},{"id":"794930026737848321","questionId":"794930024837828609","content":"系统负载","answer":0,"chooseValue":"C"},{"id":"794930026763014145","questionId":"794930024837828609","content":"吞吐量","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930171202260993","title":"<p>以下关于CISC/RISC 计算机的叙述中，不正确的是（15）。</p>","analyze":"<p>相比CISC，RISC计算机指精简指令集计算机，这种计算机有下列特点。</p><p>1.指令系统中只包含使用频率较高但不复杂的指令。</p><p>2.2.指令长度固定，指令格式少，寻址方式少。</p><p>3.只有存取数指令访问主存，其他指令都在寄存器之间运算。</p><p>4.大部分指令在一个机器周期内完成，采用流水技术。</p><p>5.CPU中增加了通用寄存器的数量。</p><p>6.硬联逻辑控制，不用微程序控制技术。</p><p>7.采用优化的编译，以有效地支持高级语言。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930173148418049"],"itemList":[{"id":"794930173093892097","questionId":"794930171202260993","content":"RISC 机器指令比 CISC 机器指令简单","answer":0,"chooseValue":"A"},{"id":"794930173110669313","questionId":"794930171202260993","content":"RISC 机器中通用寄存器比 CISC 多","answer":0,"chooseValue":"B"},{"id":"794930173131640833","questionId":"794930171202260993","content":"CISC 机器采用微程序比 RISC 多","answer":0,"chooseValue":"C"},{"id":"794930173148418049","questionId":"794930171202260993","content":"CISC 机器比 RISC机器可以更好地支持高级语言","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930205612331009","title":"<p>三个可靠度R均为0.8的部件串联构成一个系统，如下图所示：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/7f8363d7267e222e906f18d83297e6c2.jpg?x-oss-process=style/ruankaodaren\" title=\"7f8363d7267e222e906f18d83297e6c2.jpg\" alt=\"1.jpg\"/></p><p>则该系统的可靠度为（）。</p>","analyze":"本题中由三个部件串联构成系统，三个部件中任何一个部件失效就足以使系统失效。串联系统的可靠度RS=R×R×R=0.8×0.8×0.8=0.512。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930207487184897"],"itemList":[{"id":"794930207462019073","questionId":"794930205612331009","content":"0.240","answer":0,"chooseValue":"A"},{"id":"794930207487184897","questionId":"794930205612331009","content":"0.512","answer":1,"chooseValue":"B"},{"id":"794930207512350721","questionId":"794930205612331009","content":"0.800","answer":0,"chooseValue":"C"},{"id":"794930207533322241","questionId":"794930205612331009","content":"0.992","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930145700892673","title":"使用200dpi的扫描分辨率扫描一幅2×2.5英寸的黑白图像，可以得到一幅（7）像素的图像。","analyze":"在用扫描仪扫描图像时，通常要指定图像的分辨率，用每英寸多少点(dots per inch dpi)表示。用200dpi的扫描分辨率扫描一幅2×2.5英寸的黑白图像，就得到一幅400×500个像素的图像。","multi":0,"questionType":1,"answer":"C","chooseItem":["794930147579940865"],"itemList":[{"id":"794930147546386433","questionId":"794930145700892673","content":"200×2","answer":0,"chooseValue":"A"},{"id":"794930147563163649","questionId":"794930145700892673","content":"2×2.5","answer":0,"chooseValue":"B"},{"id":"794930147579940865","questionId":"794930145700892673","content":"400×500","answer":1,"chooseValue":"C"},{"id":"794930147600912385","questionId":"794930145700892673","content":"800×1000","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930137161289729","title":"内存按字节编址从A5000H到DCFFFH的区域其存储容量为（4）。","analyze":"DCFFFH-A5000H+1H=38000H=224KB","multi":0,"questionType":1,"answer":"D","chooseItem":["794930139086475265"],"itemList":[{"id":"794930139027755009","questionId":"794930137161289729","content":"123KB","answer":0,"chooseValue":"A"},{"id":"794930139048726529","questionId":"794930137161289729","content":"180KB","answer":0,"chooseValue":"B"},{"id":"794930139065503745","questionId":"794930137161289729","content":"223KB","answer":0,"chooseValue":"C"},{"id":"794930139086475265","questionId":"794930137161289729","content":"224KB","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929888220958721","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">Flynn分类法根据计算机在执行程序的过程中</span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>14）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">的不同组合，将计算机分为</span>4类。</span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">Flynn于1972年提出计算平台分类法主要根据指令流和数据流来分类，分为四类：</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">①单指令流单数据流机器(SISD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">SISD机器是一种传统的串行计算机，其硬件不支持任何形式的并行计算，所有的指令都是串行执行，并且在某个时钟周期内，CPU只能处理一个数据流。早期的计算机都是SISD机器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">②单指令流多数据流机器(SIMD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">SIMD是采用一个指令流处理多个数据流。这类机器在数字信号处理、图像处理，以及多媒体信息处理等领域非常有效。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">Intel处理器实现的MMXTM、SSE(StreamingSIMDExtensions)、SSE2及SSE3扩展指令集，都能在单个时钟周期内处理多个数据单元。也就是说人们现在用的单核计算机基本上都属于SIMD机器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">③多指令流单数据流机器(MISD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MISD是采用多个指令流来处理单个数据流。在实际情况中，采用多指令流处理多数据流才是更有效的方法，因此MISD只是作为理论模型出现，没有实际应用。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\">④多指令流多数据流机器(MIMD)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">MIMD机器可以同时执行多个指令流，这些指令流分别对不同数据流进行操作。最新的多核计算平台就属于MIMD的范畴，例如Intel和AMD的双核处理器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：（</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">14）</span><span style=\"font-family: 宋体; font-size: 10.5pt;\">A</span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929890083229697"],"itemList":[{"id":"794929890083229697","questionId":"794929888220958721","content":"指令流和数据流","answer":1,"chooseValue":"A"},{"id":"794929890095812609","questionId":"794929888220958721","content":"数据流和控制流","answer":0,"chooseValue":"B"},{"id":"794929890108395521","questionId":"794929888220958721","content":"指令流和控制流","answer":0,"chooseValue":"C"},{"id":"794929890125172737","questionId":"794929888220958721","content":"数据流和总线带宽","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929952830017537","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">内存按字节编址。若用存储容量为</span> 32Kx8bit <span style=\"font-family:宋体\">的存储器芯片构成地址从 </span><span style=\"font-family:Calibri\">A</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\">0000</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\">H <span style=\"font-family:宋体\">到 </span><span style=\"font-family:Calibri\">DFFFFH</span><span style=\"font-family:宋体\">的内存，则至少需要（ </span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">）片芯片。</span></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">存储器的字节数</span>=DFFFFH-A0000H+1=40000H=262144<span style=\"font-family:宋体\">，用</span><span style=\"font-family:Calibri\">32Kx8bit </span><span style=\"font-family:宋体\">的存储器芯片需要</span><span style=\"font-family:Calibri\">262144/32=8192/1024=8</span><span style=\"font-family:宋体\">片。</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">B</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929954692288513"],"itemList":[{"id":"794929954675511297","questionId":"794929952830017537","content":"4","answer":0,"chooseValue":"A"},{"id":"794929954692288513","questionId":"794929952830017537","content":"8","answer":1,"chooseValue":"B"},{"id":"794929954704871425","questionId":"794929952830017537","content":"16","answer":0,"chooseValue":"C"},{"id":"794929954725842945","questionId":"794929952830017537","content":"32","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929935784366081","title":"<p><span style=\"font-family: 宋体;\">总线规范会详细描述总线各方面的特性，</span><span style=\"text-indent: 0pt; font-family: 宋体; font-size: 10.5pt;\">总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总周期中并行传输4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为（61）MBps。</span></p>","analyze":"<p><span style=\"font-family: 宋体;\">总线规范会详细描述总线各方面的特性，其中物理特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总线周期中并行传输</span><span style=\"text-indent: 21pt; font-family: 宋体; font-size: 10.5pt;\">4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为 (4/2)x10=20 MBps。</span><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%; text-indent: 0pt; margin-left: 0pt;\"><span style=\"background: #7F7F7F; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family: 宋体;\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family: 宋体;\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">(61) A </span><span style=\"font-family: 宋体; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929937642442753"],"itemList":[{"id":"794929937642442753","questionId":"794929935784366081","content":"20","answer":1,"chooseValue":"A"},{"id":"794929937659219969","questionId":"794929935784366081","content":"40","answer":0,"chooseValue":"B"},{"id":"794929937675997185","questionId":"794929935784366081","content":"60","answer":0,"chooseValue":"C"},{"id":"794929937692774401","questionId":"794929935784366081","content":"80","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929996199120897","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">内存按字节编址从</span></span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">A5000H</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">到</span></span><span style=\"text-indent: 20.7pt; font-family: Courier; font-size: 10.5pt;\">DCFFFH</span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">的区域其存储容量为</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: Courier; font-size: 10.5pt;\">DCFFFH-A5000H+1H=38000H=224KB,记住，1000H=4K，10000H=64K 38000H=3*64K+8*4K=224K</span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794929998090752001"],"itemList":[{"id":"794929998044614657","questionId":"794929996199120897","content":"123KB","answer":0,"chooseValue":"A"},{"id":"794929998061391873","questionId":"794929996199120897","content":"180KB","answer":0,"chooseValue":"B"},{"id":"794929998078169089","questionId":"794929996199120897","content":"223KB","answer":0,"chooseValue":"C"},{"id":"794929998090752001","questionId":"794929996199120897","content":"224KB","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930013395767297","title":"<p><span style=\"font-size: 12pt; font-family: Calibri;\"><span style=\"font-family:宋体\">为配合防疫部门对</span>H1N1<span style=\"font-family:宋体\">流感的防控，某机场拟建设旅客体温监测系统，对每位出入机场的乘客进行体温测量并根据阈值报警，评价该系统最重要的指标是</span><span style=\"font-family:Calibri\">__</span></span><span style=\"font-size: 12pt; font-family: Calibri;\">__<span style=\"font-family:宋体\">。</span></span></p>","analyze":"<p><br/></p><p class=\"p\"><span style=\"font-family: 宋体; font-size: 12pt;\">一般情况下，正常体温范围的旅客数据不用保存，存储容量不是系统评价的重要指标。因为系统部署在机场，为了避免拥挤，系统的响应时间应尽可能地短。对于这种公众类系统，成本收益难以准确衡量，同时也不是评价该系统的重要指标。而这类系统对精确性的要求并不高，系统误差也不是重要指标。</span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">答案</span></span></strong><strong><span class=\"15\" style=\"font-family: 宋体;\">：</span></strong><span style=\"font-family: Calibri; font-size: 12pt;\">D</span></p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930015308369921"],"itemList":[{"id":"794930015253843969","questionId":"794930013395767297","content":"存储容量","answer":0,"chooseValue":"A"},{"id":"794930015270621185","questionId":"794930013395767297","content":"成本收益","answer":0,"chooseValue":"B"},{"id":"794930015287398401","questionId":"794930013395767297","content":"系统误差","answer":0,"chooseValue":"C"},{"id":"794930015308369921","questionId":"794930013395767297","content":"响应速度","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929987760181249","title":"<p><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">三总线结构的计算机总线系统由</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（ </span><span style=\"font-family:宋体\">）</span></span><span style=\"text-indent: 20.7pt; font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">组成。</span></span></p><p class=\"MsoNormal\" style=\"text-indent:20.7000pt;\"><br/></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">总线线路都可以被归为三类：即数据总线、地址总线和控制总线。</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"text-indent: 20.7pt;\"><span style=\"font-family: 黑体; font-size: 10.5pt; background: #7F7F7F;\"><span style=\"font-family:黑体\">参考答案</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">：</span></span><span style=\"font-family: Courier; font-size: 10.5pt;\">B</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929989622452225"],"itemList":[{"id":"794929989605675009","questionId":"794929987760181249","content":"CPU总线、内存总线和IO总线","answer":0,"chooseValue":"A"},{"id":"794929989622452225","questionId":"794929987760181249","content":"数据总线、地址总线和控制总线","answer":1,"chooseValue":"B"},{"id":"794929989635035137","questionId":"794929987760181249","content":"系统总线、内部总线和外部总线","answer":0,"chooseValue":"C"},{"id":"794929989647618049","questionId":"794929987760181249","content":"串行总线、并行总线和PCI总线","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930228395790337","title":"<p>内存按字节编址从A5000H到DCFFFH的区域其存储容量为（）。</p>","analyze":"<p>DCFFFH-A5000H+1H=38000H=224KB</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930230274838529"],"itemList":[{"id":"794930230232895489","questionId":"794930228395790337","content":"123KB","answer":0,"chooseValue":"A"},{"id":"794930230245478401","questionId":"794930228395790337","content":"180KB","answer":0,"chooseValue":"B"},{"id":"794930230262255617","questionId":"794930228395790337","content":"223KB","answer":0,"chooseValue":"C"},{"id":"794930230274838529","questionId":"794930228395790337","content":"224KB","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930099613880321","title":"如果主存容量为16M字节，且按字节编址，表示该主存地址至少应需要（）位。","analyze":"<p>根据主存容量或是芯片的规格求地址的位数或是数据线的数量，这种题型在软考中经常出现，只要知道规则就很容易解题。求地址线只要把主存的容量写成2的N次方的形式，这个N就是地址的位数，如题目中的16M=2^24B，所以表示该主存地址至少需要24位。其实这种规律也是从实践过程中总结出来的，我们来看几个简单的例子：</p><p>如果地址线有1根，则可以表示两种地址，即地址0和地址1，刚好满足：2^1=2；</p><p>如果地址线有2根，则可以表示四种地址，即地址00，01，10，11，满足：2^2=4；</p><p>如果地址线有3根，则可以表示八种地址，也满足：2^3=8；</p><p>依此类推，就把规律总结出来了。</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930101509705729"],"itemList":[{"id":"794930101463568385","questionId":"794930099613880321","content":"16","answer":0,"chooseValue":"A"},{"id":"794930101484539905","questionId":"794930099613880321","content":"20","answer":0,"chooseValue":"B"},{"id":"794930101509705729","questionId":"794930099613880321","content":"24","answer":1,"chooseValue":"C"},{"id":"794930101530677249","questionId":"794930099613880321","content":"32","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930267218268161","title":"使用200dpi的扫描分辨率扫描一幅2×2.5英寸的黑白图像，可以得到一幅（）像素的图像。","analyze":"在用扫描仪扫描图像时，通常要指定图像的分辨率，用每英寸多少点(dots per inch dpi)表示。用200dpi的扫描分辨率扫描一幅2×2.5英寸的黑白图像，就得到一幅400×500个像素的图像。","multi":0,"questionType":1,"answer":"C","chooseItem":["794930269097316353"],"itemList":[{"id":"794930269063761921","questionId":"794930267218268161","content":"00×2","answer":0,"chooseValue":"A"},{"id":"794930269076344833","questionId":"794930267218268161","content":"2×2.5","answer":0,"chooseValue":"B"},{"id":"794930269097316353","questionId":"794930267218268161","content":"400×500","answer":1,"chooseValue":"C"},{"id":"794930269109899265","questionId":"794930267218268161","content":"800×1000","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930177091063809","title":"在显存中，表示黑白自像的像素点最少需（63）个二进制位。","analyze":"0表黑，1表白，仅需一位。","multi":0,"questionType":1,"answer":"A","chooseItem":["794930178953334785"],"itemList":[{"id":"794930178953334785","questionId":"794930177091063809","content":"1","answer":1,"chooseValue":"A"},{"id":"794930178986889217","questionId":"794930177091063809","content":"2","answer":0,"chooseValue":"B"},{"id":"794930179028832257","questionId":"794930177091063809","content":"8","answer":0,"chooseValue":"C"},{"id":"794930179066580993","questionId":"794930177091063809","content":"16","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930134309163009","title":"属于CPU中算术逻辑单元的部件是在 （3） 。","analyze":"算术逻辑运算单元ALU(Arithmetic and Logic Unit)ALU主要完成对二进制数据的定点算术运算(加减乘除)、逻辑运算(与或非异或)以及移位操作。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930136200794113"],"itemList":[{"id":"794930136179822593","questionId":"794930134309163009","content":"程序计数器","answer":0,"chooseValue":"A"},{"id":"794930136200794113","questionId":"794930134309163009","content":"加法器","answer":1,"chooseValue":"B"},{"id":"794930136217571329","questionId":"794930134309163009","content":"指令寄存器","answer":0,"chooseValue":"C"},{"id":"794930136238542849","questionId":"794930134309163009","content":"指令译码器","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929975445704705","title":"<p><span style=\"font-family: Calibri; font-size: 12pt;\">JPEG</span><span style=\"font-family:宋体\">压缩编码算法中，</span><span style=\"font-family:Calibri\">____</span><span style=\"font-family:宋体\">是错误的。</span></p>","analyze":"<p><span style=\"font-family: Calibri; font-size: 12pt;\">JPEG</span><span style=\"font-family:宋体\">标准是一个适用于彩色和单色多灰度或连续色调静止数字图像的压缩标准，它包括基于</span><span style=\"font-family:Calibri\">DPCM</span><span style=\"font-family:宋体\">（差分脉冲编码调制）和</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">（离散余弦变换）的无损压缩算法，以及基于</span><span style=\"font-family:Calibri\">Huffman</span><span style=\"font-family:宋体\">编码的有损压缩算法两个部分。前者不会产生失真，但压缩比很小；后一种算法进行图像压缩时信息虽有损失，但压缩比可以很大，例如，压缩</span><span style=\"font-family:Calibri\">20</span><span style=\"font-family:宋体\">倍左右时，人眼基本上看不出失真。</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">标准实际上有三个范畴。</span><br/></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>1<span style=\"font-family:宋体\">）基本顺序过程（</span><span style=\"font-family:Calibri\">Baseline Sequential Processes</span><span style=\"font-family:宋体\">）实现有损图像压缩，重建图像质量达到人眼难以观察出来的要求。采用的是</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">像素自适应</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">算法、量化及</span><span style=\"font-family:Calibri\">Huffman</span><span style=\"font-family:宋体\">型的熵编码器。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>2<span style=\"font-family:宋体\">）基于</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">的扩展过程（</span><span style=\"font-family:Calibri\">Extended DCT Based Process</span><span style=\"font-family:宋体\">）使用累进工作方式，采用自适应算术编码过程。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>3<span style=\"font-family:宋体\">）无失真过程（</span><span style=\"font-family:Calibri\">Lossless Process</span><span style=\"font-family:宋体\">）采用预测编码及</span><span style=\"font-family:Calibri\">Huffman</span><span style=\"font-family:宋体\">编码（或算术编码），可保证重建图像数据与原始图像数据完全相同。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">其中的基本顺序过程是</span>JPEG<span style=\"font-family:宋体\">最基本的压缩过程，符合</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">标准的硬软件编码</span><span style=\"font-family:Calibri\">/</span><span style=\"font-family:宋体\">解码器都必须支持和实现这个过程。另两个过程是可选扩展，对一些特定的应用项目有很大实用价值。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>1<span style=\"font-family:宋体\">）</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">算法。基本</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">算法操作可分成以下三个步骤：通过离散余弦变换（</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">）去除数据冗余；使用量化表对</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">系数进行量化，量化表是根据人类视觉系统和压缩图像类型的特点进行优化的量化系数矩阵；对量化后的</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">系数进行编码使其熵达到最小，熵编码采用</span><span style=\"font-family:Calibri\">Huffman</span><span style=\"font-family:宋体\">可变字长编码。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>2<span style=\"font-family:宋体\">）离散余弦变换。</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">采用</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">子块的二维离散余弦变换算法。在编码器的输入端，把原始图像（对彩色图像是每个颜色成分）顺序地分割成一系列</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">的子块。在</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">图像块中，像素值一般变化较平缓，因此具有较低的空间频率。实施二维</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">离散余弦变换可以将图像块的能量集中在极少数系数上，其他系数的值与这些系数相比，绝对值要小得多。与</span><span style=\"font-family:Calibri\">Fourier</span><span style=\"font-family:宋体\">变换类似，对于高度相关的图像数据进行这样变换的效果使能量高度集中，便于后续的压缩处理。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>3<span style=\"font-family:宋体\">）量化。为了达到压缩数据的目的，对</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">系数需做量化处理。量化的作用是在保持一定质量前提下，丢弃图像中对视觉效果影响不大的信息。量化是多对一映射，是造成</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">编码信息损失的根源。</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">标准中采用线性均匀量化器，量化过程为对</span><span style=\"font-family:Calibri\">64</span><span style=\"font-family:宋体\">个</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">系数除以量化步长并四舍五入取整，量化步长由量化表决定。量化表元素因</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">系数位置和彩色分量的不同而取不同值。量化表为</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">矩阵，与</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">变换系数一一对应。量化表一般由用户规定</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">标准中给出参考值，并作为编码器的一个输入。量化表中元素为</span><span style=\"font-family:Calibri\">1</span><span style=\"font-family:宋体\">到</span><span style=\"font-family:Calibri\">255</span><span style=\"font-family:宋体\">之间的任意整数，其值规定了其所对应</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">系数的量化步长。</span><span style=\"font-family:Calibri\">DCT</span><span style=\"font-family:宋体\">变换系数除以量化表中对应位置的量化步长并舍去小数部分后多数变为零，从而达到了压缩的目的。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>4<span style=\"font-family:宋体\">）行程长度编码（</span><span style=\"font-family:Calibri\">RLE</span><span style=\"font-family:宋体\">）。</span><span style=\"font-family:Calibri\">64</span><span style=\"font-family:宋体\">个变换系数经量化后，左上角系数是直流分量（</span><span style=\"font-family:Calibri\">DC</span><span style=\"font-family:宋体\">系数），即空间域中</span><span style=\"font-family:Calibri\">64</span><span style=\"font-family:宋体\">个图像采样值的均值。相邻</span><span style=\"font-family:Calibri\">8*8</span><span style=\"font-family:宋体\">块之间的</span><span style=\"font-family:Calibri\">DC</span><span style=\"font-family:宋体\">系数一般有很强的相关性，</span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">标准对</span><span style=\"font-family:Calibri\">DC</span><span style=\"font-family:宋体\">系数采用</span><span style=\"font-family:Calibri\">DPCM</span><span style=\"font-family:宋体\">编码方法，即对相邻像素块之间的</span><span style=\"font-family:Calibri\">L</span><span style=\"font-family:宋体\">系数的差值进行编码。其余</span><span style=\"font-family:Calibri\">63</span><span style=\"font-family:宋体\">个交流分量（</span><span style=\"font-family:Calibri\">AC</span><span style=\"font-family:宋体\">系数）使用</span><span style=\"font-family:Calibri\">RLE</span><span style=\"font-family:宋体\">编码，从左上角开始沿对角线方向，以</span><span style=\"font-family:Calibri\">Z</span><span style=\"font-family:宋体\">字形（</span><span style=\"font-family:Calibri\">Zig-Zag</span><span style=\"font-family:宋体\">）进行扫描直至结束。量化后的</span><span style=\"font-family:Calibri\">AC</span><span style=\"font-family:宋体\">系数通常会有许多零值，以</span><span style=\"font-family:Calibri\">Z</span><span style=\"font-family:宋体\">字形路径进行游程编码有效地增加了连续出现的零值个数。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"><span style=\"font-family:宋体\">（</span>5<span style=\"font-family:宋体\">）熵编码。为了进一步压缩数据，对</span><span style=\"font-family:Calibri\">DC</span><span style=\"font-family:宋体\">码和</span><span style=\"font-family:Calibri\">AC</span><span style=\"font-family:宋体\">行程编码的码字再做基于统计特性的熵编码。 </span><span style=\"font-family:Calibri\">JPEG</span><span style=\"font-family:宋体\">标准建议使用的熵编码方法有</span><span style=\"font-family:Calibri\">Huffman</span><span style=\"font-family:宋体\">编码和自适应二进制算术编码。</span></span><span style=\"mso-spacerun:'yes';font-family:Calibri;mso-fareast-font-family:宋体;mso-bidi-font-family:'Times New Roman';font-size:12.0000pt;mso-font-kerning:0.0000pt;\"></span></p><p class=\"p\"><strong><span class=\"15\" style=\"font-family: "Times New Roman";\"><span style=\"font-family:宋体\">答案</span></span></strong><span style=\"font-family: Calibri; font-size: 12pt;\">B</span></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794929977370890241"],"itemList":[{"id":"794929977349918721","questionId":"794929975445704705","content":"JPEG算法与图像的彩色空间无关","answer":0,"chooseValue":"A"},{"id":"794929977370890241","questionId":"794929975445704705","content":"对变换后的系数进行量化是一种无损压缩过程","answer":1,"chooseValue":"B"},{"id":"794929977387667457","questionId":"794929975445704705","content":"量化后的交流系数（AC）使用行程长度编码（RLE）方法","answer":0,"chooseValue":"C"},{"id":"794929977404444673","questionId":"794929975445704705","content":"量化后的直流系数（DC）使用差分脉冲调制编码（DPCM）方法","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929919661461505","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt; mso-spacerun: "yes"; mso-font-kerning: 1.0000pt;\"><span style=\"font-family: 宋体;\">使用多处理机系统的主要目的是实现</span></span><span style=\"text-decoration: underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family: 宋体;\">（</span>14）</span></span><span style=\"font-family: 宋体; font-size: 10.5pt; mso-spacerun: "yes"; mso-font-kerning: 1.0000pt;\"><span style=\"font-family: 宋体;\">代码的并行性。</span></span></p>","analyze":"<p>在多处理机系统中，提高程序并行性的关键，是把任务分解成足够多的可同时操作的进程，即实现作业级和任务级的并行。</p><p><br/></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794929921553092609"],"itemList":[{"id":"794929921523732481","questionId":"794929919661461505","content":"操作级和指令级 <br/>","answer":0,"chooseValue":"A"},{"id":"794929921540509697","questionId":"794929919661461505","content":"指令级和作业级 <br/>","answer":0,"chooseValue":"B"},{"id":"794929921553092609","questionId":"794929919661461505","content":"作业级和任务级 <br/> <br/>","answer":1,"chooseValue":"C"},{"id":"794929921574064129","questionId":"794929919661461505","content":"任务级和指令级 <br/>","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929902548701185","title":"<p><br/></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">当用户开机按下</span>PC机电源开关对，PC机首先执行的是</span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>46）</span></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">BIOS引导程序是固化在ROM芯片上的，每当开机时自动执行BIOS引导程序。它主要执行如下任务：</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•标识和配置所有的即插即用设备。如果系统有即插即用设备的BIOS，系统将搜索和测试所有安装的即插即用设备，并为它们分配DMA通道、IRQ及它们需要的其他设备。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•完成加电自检(POST)。加电自检主要检测和测试内存、端口、键盘、视频适配器、磁盘驱动器等基本设备。有一些新版本的系统还支持CD-ROM驱动器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•对引导驱动器可引导分区定位。在CMOS中，用户可以设置系统的引导顺序，以便对引导驱动器的可引导分区重新定位。大多数系统的引导顺序是软件驱动，然后是硬件驱动，其次是CD-ROM驱动器。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">•加载主引导记录及引导驱动器的分区表，执行主引导记录MBR。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">主引导记录在硬盘上找到可引导分区后，将其分区引导记录装入内存，并将控制权交给分区引导记录。由分区引导记录定位根目录，再装入操作系统。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\"><span style=\"font-family: 宋体; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：</span></span><span style=\"font-family: 宋体; font-size: 10.5pt;\">(46)</span><span style=\"font-family: 宋体; font-size: 10.5pt;\">C</span></p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794929904444526593"],"itemList":[{"id":"794929904410972161","questionId":"794929902548701185","content":"硬盘上主引导记录","answer":0,"chooseValue":"A"},{"id":"794929904427749377","questionId":"794929902548701185","content":"硬盘上分区引导记录","answer":0,"chooseValue":"B"},{"id":"794929904444526593","questionId":"794929902548701185","content":"主板上的BIOS引导程序","answer":1,"chooseValue":"C"},{"id":"794929904461303809","questionId":"794929902548701185","content":"软盘上的引导记录","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794929894059429889","title":"<p><br/></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">下列关于虚拟存储器的叙述中，正确的是</span></span><span style=\"text-decoration:underline;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">（</span>16）</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">。</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","analyze":"<p><br/></p><p class=\"MsoNormal\" style=\"text-indent: 21pt; line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">所有的存储器设备按照一定的层次逻辑关系通过软硬件连接起来，并进行有效的管理，就形成了存储体系。一般计算机系统中主要有两种存储体系：</span>Cache存储体系(由Cache和主存储器构成，主要目的是提高存储器访问速度(和虚拟存储体系(由主存储器和在线磁盘存储器构成，主要目的是扩大存储器容量(。其中Cache存储体系对系统程序员以上均透明，而虚拟存储体系对应用程序员透明，对系统程序员不透明。</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p><p class=\"MsoNormal\" style=\"line-height: 150%;\"><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"><span style=\"font-family:宋体\">参考答案：（</span></span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">16）</span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\">A </span><span style=\"font-family: 宋体; line-height: 150%; font-size: 10.5pt;\"></span></p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794929895904923649"],"itemList":[{"id":"794929895904923649","questionId":"794929894059429889","content":"对应用程序员透明，对系统程序员不透明","answer":1,"chooseValue":"A"},{"id":"794929895921700865","questionId":"794929894059429889","content":"对应用程序员不透明，对系统程序员透明","answer":0,"chooseValue":"B"},{"id":"794929895942672385","questionId":"794929894059429889","content":"对应用程序员、系统程序员都不透明","answer":0,"chooseValue":"C"},{"id":"794929895959449601","questionId":"794929894059429889","content":"对应用程序员、系统程序员都透明","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930057586954241","title":"<p>CPU的频率有主频、倍频和外频。某处理器外频是200 MHz，倍频是13，该款处理器的主频是（ ）。</p>","analyze":"<p>CPU的工作频率（主频）= 外频倍频。</p><p>外频就是外部频率，指的是系统总线频率。</p><p>倍频的全称是“倍频系数”，是指CPU主频与外频之间的相对比例关系。最初CPU主频和系统总线速度是一样的，但CPU的速度越来越快，倍频技术也就相应产生。它的作用是使系统总线工作在相对较低的频率上，而CPU速度可以通过倍频来提升。</p><p>本题中外频200 MHz，倍频13，所以主频=200 MHz13=2.6 GHz。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930059616997377"],"itemList":[{"id":"794930059616997377","questionId":"794930057586954241","content":"2.6 GHz","answer":1,"chooseValue":"A"},{"id":"794930059642163201","questionId":"794930057586954241","content":"1300 MHz","answer":0,"chooseValue":"B"},{"id":"794930059658940417","questionId":"794930057586954241","content":"15.38 MHz","answer":0,"chooseValue":"C"},{"id":"794930059684106241","questionId":"794930057586954241","content":"200 MHz","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930182916952065","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>在磁盘上存储数据的排列方式会影响IO服务的总时间。假设每个磁道被划分成10个物理块，每个物理块存放1个逻辑记录。逻辑记录R1, R2,.....,R10存放在同一个磁道上，记录的排列顺序如下表所示。</p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/d85965115d163a4161c2708f1b093361.png?x-oss-process=style/ruankaodaren\" title=\"d85965115d163a4161c2708f1b093361.png\" alt=\"image.png\"/><br/><p>假定磁盘的旋转速度为10ms/周，磁头当前处在R1的开始处。若系统顺序处理这些记录，使用单缓冲区，每个记录处理时间为2ms,则处理这10个记录的最长时间为( ) ;若对存储数据的排列顺序进行优化，处理10个记录的最少时间为( )。</p>","analyze":"<p>磁头当前处于R1 处，读取出R1的时间为10ms/10=1ms，然后的使用单缓冲区处理，花费2ms。R1处理完毕后磁头此时已处于R4处，若是顺序读和处理R2则需要再等待8ms，R2的读取与处理时间与R1相同，当R2处理完毕再读取 R3 仍然需要再等待8 ms......依次类推，10个记录读完处理完毕的时间一共是102ms（要转10圈，所以是10*10=100ms，在加上最后一个读取花费的2ms，一共是100ms+2ms=102ms）。若对存储数据的排列顺序进行优化，即在原先存放R4处，存放R2，则十个记录的处理时间会缩短至30ms（一圈顺序处理4个，2圈半就处理完了，2圈半花费的时间=3*10=30ms）。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930184808583169"],"itemList":[{"id":"794930184766640129","questionId":"794930182916952065","content":"30ms","answer":0,"chooseValue":"A"},{"id":"794930184779223041","questionId":"794930182916952065","content":"60ms","answer":0,"chooseValue":"B"},{"id":"794930184796000257","questionId":"794930182916952065","content":"94ms","answer":0,"chooseValue":"C"},{"id":"794930184808583169","questionId":"794930182916952065","content":"102ms","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930159831502849","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p>在计算机的浮点数表示中，主要影响数值表示范围的是 （11），影响计算精度的是 （12）。","analyze":"<p>在计算机中浮点数的表示形式是：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/492146023efb5393735a90bf41ed5262.jpg?x-oss-process=style/ruankaodaren\" title=\"492146023efb5393735a90bf41ed5262.jpg\" alt=\"1.jpg\"/></p><p>其中F是浮点数的尾数，E为浮点数的阶码。影响数值表示范围的是阶码的位数，尾数的位数影响计算的精度。<br/></p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930161697968129"],"itemList":[{"id":"794930161676996609","questionId":"794930159831502849","content":"尾数的位数","answer":0,"chooseValue":"A"},{"id":"794930161697968129","questionId":"794930159831502849","content":"阶码的位数","answer":1,"chooseValue":"B"},{"id":"794930161727328257","questionId":"794930159831502849","content":"规格化的方法","answer":0,"chooseValue":"C"},{"id":"794930161756688385","questionId":"794930159831502849","content":"尾数下溢的处理","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930234024546305","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>以下媒体中（）是表示媒体，（）是表现媒体。</p>","analyze":"<p>表示媒体是为了加工、处理和传输感觉媒体而人为研究、构造出来的一种媒体，它有各种编码方式，如：文本编码、图像编码和声音编码等。</p><p>表现媒体是指进行信息输入和输出的媒体，如：键盘、鼠标、扫捕仪、话筒和摄像机等输入媒体以及显示器、打印机和扬声器等输出媒体。</p><p>感觉媒体是指直接作用于人的感觉器官，使人产生直接感觉的媒体，如：引起听觉反应的声音，引起视觉反应的文本、图形和图像等。</p><p>存储媒体是指用于存储表示媒体的物理介质，如：硬盘、软盘、光盘和胶卷等。</p><p>传输媒体是指用于存储表示媒体的物理介质，如：电缆和光缆等。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930235895205889"],"itemList":[{"id":"794930235874234369","questionId":"794930234024546305","content":"声音","answer":0,"chooseValue":"A"},{"id":"794930235895205889","questionId":"794930234024546305","content":"声音编码","answer":1,"chooseValue":"B"},{"id":"794930235911983105","questionId":"794930234024546305","content":"超声波","answer":0,"chooseValue":"C"},{"id":"794930235932954625","questionId":"794930234024546305","content":"喇叭","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930148511076353","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p>以下媒体中（8）是表示媒体，（9）是表现媒体。","analyze":"<p>表示媒体是为了加工、处理和传输感觉媒体而人为研究、构造出来的一种媒体，它有各种编码方式，如：文本编码、图像编码和声音编码等。</p><p>表现媒体是指进行信息输入和输出的媒体，如：键盘、鼠标、扫捕仪、话筒和摄像机等输入媒体以及显示器、打印机和扬声器等输出媒体。</p><p>感觉媒体是指直接作用于人的感觉器官，使人产生直接感觉的媒体，如：引起听觉反应的声音，引起视觉反应的文本、图形和图像等。</p><p>存储媒体是指用于存储表示媒体的物理介质，如：硬盘、软盘、光盘和胶卷等。</p><p>传输媒体是指用于存储表示媒体的物理介质，如：电缆和光缆等。</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930150394318849"],"itemList":[{"id":"794930150373347329","questionId":"794930148511076353","content":"声音","answer":0,"chooseValue":"A"},{"id":"794930150394318849","questionId":"794930148511076353","content":"声音编码","answer":1,"chooseValue":"B"},{"id":"794930150415290369","questionId":"794930148511076353","content":"超声波","answer":0,"chooseValue":"C"},{"id":"794930150444650497","questionId":"794930148511076353","content":"喇叭","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930139988250625","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>数据存储在磁盘上的排列方式会影响I/O服务的总时间。假设每磁道划分成10个物理块，每块存放1个逻辑记录。逻辑记录R1，R2，…，R10存放在同一个磁道上，记录的安排顺序如下表所示：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/db843643c00efdb0b99b3d7a5f492d6a.jpg?x-oss-process=style/ruankaodaren\" title=\"db843643c00efdb0b99b3d7a5f492d6a.jpg\" alt=\"1.jpg\"/><br/>假定磁盘的旋转速度为20ms/周，磁头当前处在R1的开始处。若系统顺序处理这些记录，使用单缓冲区，每个记录处理时间为4ms，则处理这10个记录的最长时间为（）；若对信息存储进行优化分布后，处理10个记录的最少时间为（）。</p>","analyze":"<p>系统读记录的时间为20/10=2ms。系统读出并处理记录R1之后，磁头已经转到记录R4的开始处，所以为了读出记录R2，磁盘必须再转一圈，需要2ms(读记录)加20ms(转一圈)的时间。这样，处理10个记录的总时间应为处理前9个记录(即R1， R2，…，R9)的总时间再加上读R10和处理时间(9×22ms+6ms=204ms)。</p><p>对于第二种情况，若对信息进行分布优化的结果如下所示：<br/><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/cdce85d0ea703daab306be55ac2cfbe3.jpg?x-oss-process=style/ruankaodaren\" title=\"cdce85d0ea703daab306be55ac2cfbe3.jpg\" alt=\"1.jpg\"/></p><p>从上图可以看出，当读出记录R1并处理结束后，磁头刚好转至R2记录的开始处，立即就可以读出并处理，因此处理10个记录的总时间为：</p><p>10×(2ms(读记录)+4ms(处理记录))=10×6ms=60ms</p>","multi":0,"questionType":1,"answer":"C","chooseItem":["794930141917630465"],"itemList":[{"id":"794930141858910209","questionId":"794930139988250625","content":"180ms","answer":0,"chooseValue":"A"},{"id":"794930141888270337","questionId":"794930139988250625","content":"200ms","answer":0,"chooseValue":"B"},{"id":"794930141917630465","questionId":"794930139988250625","content":"204ms","answer":1,"chooseValue":"C"},{"id":"794930141946990593","questionId":"794930139988250625","content":"220ms","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930154164998145","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>某计算机系统的CPU主频为2.8GHz。某应用程序包括3类指令，各类指令的CPI（执行每条指令所需要的时钟周期数）及指令比例如下表所示。执行该应用程序时的平均CPI为（2）；运算速度用MIPS 表示，约为（3）。</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/09534555a2705875621ccd5a5e198cb0.jpg?x-oss-process=style/ruankaodaren\" title=\"09534555a2705875621ccd5a5e198cb0.jpg\" alt=\"1.jpg\"/></p><br/>","analyze":"<p>平均执行周期数（Cycle Per Instruction，CPI ）是指CPU每执行一条指令所需的时钟周期数。</p><p>本题已经给出了三条指令的CPI，那么平均CPI为：4*35%+3*45%+6*20%=4</p><p>每秒百万级指令执行数量（Million Instructions Per Second，MIPS）＝指令条数/（执行时间×106）＝主频/CPI=2.8G/4=700MIPS。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930156060823553"],"itemList":[{"id":"794930156010491905","questionId":"794930154164998145","content":"25","answer":0,"chooseValue":"A"},{"id":"794930156027269121","questionId":"794930154164998145","content":"3","answer":0,"chooseValue":"B"},{"id":"794930156044046337","questionId":"794930154164998145","content":"3.5","answer":0,"chooseValue":"C"},{"id":"794930156060823553","questionId":"794930154164998145","content":"4","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930272851218433","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks, RAID）机制中共分 （8） 级别， RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中， （9） 是由单一的磁盘负责冗余和数据校验； （10） 由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用； （11） 兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。","analyze":"<p>RAID等级分为8个级别。RAID 0是无冗余和无校验的数据分块；RAID 1每一个工作盘都有其对应的镜像盘，磁盘空间利用率为50%；RAID3由单一的独立磁盘负责冗余和数据校验；RAID5由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用；RAID 10采用RAID0和RAID1组合而成，兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。</p><p>参考答案：（8）B；（9）D；（10）D；（11）A</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930274776403969"],"itemList":[{"id":"794930274751238145","questionId":"794930272851218433","content":"7个","answer":0,"chooseValue":"A"},{"id":"794930274776403969","questionId":"794930272851218433","content":"8个","answer":1,"chooseValue":"B"},{"id":"794930274801569793","questionId":"794930272851218433","content":"6个","answer":0,"chooseValue":"C"},{"id":"794930274826735617","questionId":"794930272851218433","content":"9个","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930284880482305","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>给定关系模式R<U,F>，其中：属性集U={A,B,C,D,E,G}，函数依赖集F={A→BD，C→A，AE→G}。因为 （15） =U，且满足最小性，所以其为R的候选码；若将R分解为如下两个关系模式 （16） ，则分解后的关系模式保持函数依赖。</p>","analyze":"<p>CE只在函数依赖集F的左部，且能推出属性集U。所以<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/52800ed1933731041eee308c90fa187a.png?x-oss-process=style/ruankaodaren\" title=\"52800ed1933731041eee308c90fa187a.png\" alt=\"image.png\" width=\"74\" height=\"18\"/>，CE必为R的候选码。</p><p>A选项中，R1(A,B,C)和R2（D,E,G）分别得到函数依赖集F1=｛A→B,C→A｝、F2=φ，F1+F2≠F，则分解后的关系模式不能保持函数依赖。</p><p>B选项中，R1(B,C,D,E)和R2（A,E,G）分别得到函数依赖集F1=φ、F2=｛AE→G｝，F1+F2≠F，则分解后的关系模式不能保持函数依赖。</p><p>C选项中，R1(B,C,D)和R2（A,E,G）分别得到函数依赖集F1=φ、F2=｛AE→G｝，F1+F2≠F，则分解后的关系模式不能保持函数依赖。</p><p>D选项中，R1(A,B,C,D)和R2（A,E,G）分别得到函数依赖集F1=｛A→B,A→D,C→A｝、F2=｛AE→G｝，F1+F2=F，则分解后的关系模式能保持函数依赖。</p><p>参考答案：（15）D；（16）D</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930287162183681"],"itemList":[{"id":"794930287090880513","questionId":"794930284880482305","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/291b731569dc327d58d77247e3edc63b.png?x-oss-process=style/ruankaodaren\" title=\"291b731569dc327d58d77247e3edc63b.png\" alt=\"image.png\"/><br/>","answer":0,"chooseValue":"A"},{"id":"794930287116046337","questionId":"794930284880482305","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/3671436a03af4292b3da055a5d044328.png?x-oss-process=style/ruankaodaren\" title=\"3671436a03af4292b3da055a5d044328.png\" alt=\"image.png\"/>","answer":0,"chooseValue":"B"},{"id":"794930287137017857","questionId":"794930284880482305","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/647d959c3d62b324a67cef7fb8a49cee.png?x-oss-process=style/ruankaodaren\" title=\"647d959c3d62b324a67cef7fb8a49cee.png\" alt=\"image.png\"/>","answer":0,"chooseValue":"C"},{"id":"794930287162183681","questionId":"794930284880482305","content":"<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/1aa5e69e1cfb2198bf5e3258c85a5e41.png?x-oss-process=style/ruankaodaren\" title=\"1aa5e69e1cfb2198bf5e3258c85a5e41.png\" alt=\"image.png\"/>","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930188549902337","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>为了优化系统的性能，有时需要对系统进行调整。对于不同的系统，其调整参数也不尽相同。例如，对于数据库系统，主要包括 CPU/内存使用状况、（56）、进程/线程使用状态、日志文件大小等。对于应用系统，主要包括应用系统的可用性、响应时间、（57）、特定应用资源占用等。</p>","analyze":"<p>为了优化系统性能，有时需要对系统进行调整。对于数据库系统，性能调整主要包括 CPU／内存使用状 况、优化数据库设计、优化数据库管理以及进程/线程状态、硬盘剩余空间、日志文件大小等；对于应用系统， 性能调整主要包括应用系统的可用性、响应时间、并发用户数以及特定应用的系统资源占用等。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930190445727745"],"itemList":[{"id":"794930190395396097","questionId":"794930188549902337","content":"数据丢包率","answer":0,"chooseValue":"A"},{"id":"794930190412173313","questionId":"794930188549902337","content":"端口吞吐量","answer":0,"chooseValue":"B"},{"id":"794930190428950529","questionId":"794930188549902337","content":"数据处理速率","answer":0,"chooseValue":"C"},{"id":"794930190445727745","questionId":"794930188549902337","content":"查询语句性能","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930245256892417","title":"<p><strong>请作答第<span style=\"color: red\">1</span>空。</strong></p><p>计算机系统中， （10） 方式是根据所访问的内容来决定要访问的存储单元，常用在 （11） 存储器中。</p>","analyze":"相联存取是一种随机存取，但是选择某一单元进行读写是取决于其内容而不是其地址。与普通的随机存取方式一样，每个单元都有自己的读写装置，读写时间也是一个常数。使用相联存取方式，可以对所有的存储单元的特定位进行比较，选择符合条件的单元进行访问。为了提高地址映射的速度，Cache采取相联存取的方式。","multi":0,"questionType":1,"answer":"C","chooseItem":["794930247190466561"],"itemList":[{"id":"794930247156912129","questionId":"794930245256892417","content":"顺序存取","answer":0,"chooseValue":"A"},{"id":"794930247173689345","questionId":"794930245256892417","content":"直接存取","answer":0,"chooseValue":"B"},{"id":"794930247190466561","questionId":"794930245256892417","content":"相联存取","answer":1,"chooseValue":"C"},{"id":"794930247211438081","questionId":"794930245256892417","content":"零存整取","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930191355891713","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>为了优化系统的性能，有时需要对系统进行调整。对于不同的系统，其调整参数也不尽相同。例如，对于数据库系统，主要包括 CPU/内存使用状况、（56）、进程/线程使用状态、日志文件大小等。对于应用系统，主要包括应用系统的可用性、响应时间、（57）、特定应用资源占用等。</p>","analyze":"<p>为了优化系统性能，有时需要对系统进行调整。对于数据库系统，性能调整主要包括 CPU／内存使用状 况、优化数据库设计、优化数据库管理以及进程/线程状态、硬盘剩余空间、日志文件大小等；对于应用系统， 性能调整主要包括应用系统的可用性、响应时间、并发用户数以及特定应用的系统资源占用等。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930193230745601"],"itemList":[{"id":"794930193230745601","questionId":"794930191355891713","content":"并发用户数","answer":1,"chooseValue":"A"},{"id":"794930193247522817","questionId":"794930191355891713","content":"支持协议和标准","answer":0,"chooseValue":"B"},{"id":"794930193264300033","questionId":"794930191355891713","content":"最大连接数","answer":0,"chooseValue":"C"},{"id":"794930193285271553","questionId":"794930191355891713","content":"时延抖动","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930185718747137","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>在磁盘上存储数据的排列方式会影响IO服务的总时间。假设每个磁道被划分成10个物理块，每个物理块存放1个逻辑记录。逻辑记录R1, R2,.....,R10存放在同一个磁道上，记录的排列顺序如下表所示。</p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/d85965115d163a4161c2708f1b093361.png?x-oss-process=style/ruankaodaren\" title=\"d85965115d163a4161c2708f1b093361.png\" alt=\"image.png\"/><br/><p>假定磁盘的旋转速度为10ms/周，磁头当前处在R1的开始处。若系统顺序处理这些记录，使用单缓冲区，每个记录处理时间为2ms,则处理这10个记录的最长时间为( ) ;若对存储数据的排列顺序进行优化，处理10个记录的最少时间为( )。</p>","analyze":"<p>磁头当前处于R1 处，读取出R1的时间为10ms/10=1ms，然后的使用单缓冲区处理，花费2ms。R1处理完毕后磁头此时已处于R4处，若是顺序读和处理R2则需要再等待8ms，R2的读取与处理时间与R1相同，当R2处理完毕再读取 R3 仍然需要再等待8 ms......依次类推，10个记录读完处理完毕的时间一共是102ms。若对存储数据的排列顺序进行优化，即在原先存放R4处，存放R2，则十个记录的处理时间会缩短至30ms。 </p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930187572629505"],"itemList":[{"id":"794930187572629505","questionId":"794930185718747137","content":"30ms","answer":1,"chooseValue":"A"},{"id":"794930187593601025","questionId":"794930185718747137","content":"60ms","answer":0,"chooseValue":"B"},{"id":"794930187614572545","questionId":"794930185718747137","content":"94ms","answer":0,"chooseValue":"C"},{"id":"794930187635544065","questionId":"794930185718747137","content":"102ms","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930142869737473","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>数据存储在磁盘上的排列方式会影响I/O服务的总时间。假设每磁道划分成10个物理块，每块存放1个逻辑记录。逻辑记录R1，R2，…，R10存放在同一个磁道上，记录的安排顺序如下表所示：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/db843643c00efdb0b99b3d7a5f492d6a.jpg?x-oss-process=style/ruankaodaren\" title=\"db843643c00efdb0b99b3d7a5f492d6a.jpg\" alt=\"1.jpg\"/><br/>假定磁盘的旋转速度为20ms/周，磁头当前处在R1的开始处。若系统顺序处理这些记录，使用单缓冲区，每个记录处理时间为4ms，则处理这10个记录的最长时间为（）；若对信息存储进行优化分布后，处理10个记录的最少时间为（）。</p>","analyze":"<p>系统读记录的时间为20/10=2ms。系统读出并处理记录R1之后，磁头已经转到记录R4的开始处，所以为了读出记录R2，磁盘必须再转一圈，需要2ms(读记录)加20ms(转一圈)的时间。这样，处理10个记录的总时间应为处理前9个记录(即R1， R2，…，R9)的总时间再加上读R10和处理时间(9×22ms+6ms=204ms)。</p><p>对于第二种情况，若对信息进行分布优化的结果如下所示：<br/><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/cdce85d0ea703daab306be55ac2cfbe3.jpg?x-oss-process=style/ruankaodaren\" title=\"cdce85d0ea703daab306be55ac2cfbe3.jpg\" alt=\"1.jpg\"/></p><p>从上图可以看出，当读出记录R1并处理结束后，磁头刚好转至R2记录的开始处，立即就可以读出并处理，因此处理10个记录的总时间为：</p><p>10×(2ms(读记录)+4ms(处理记录))=10×6ms=60ms</p>","multi":0,"questionType":1,"answer":"B","chooseItem":["794930144752979969"],"itemList":[{"id":"794930144736202753","questionId":"794930142869737473","content":"40ms","answer":0,"chooseValue":"A"},{"id":"794930144752979969","questionId":"794930142869737473","content":"60ms","answer":1,"chooseValue":"B"},{"id":"794930144773951489","questionId":"794930142869737473","content":"100ms","answer":0,"chooseValue":"C"},{"id":"794930144790728705","questionId":"794930142869737473","content":"160ms","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930288198176769","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>给定关系模式R<U,F>，其中：属性集U={A,B,C,D,E,G}，函数依赖集F={A→BD，C→A，AE→G}。因为 （15） =U，且满足最小性，所以其为R的候选码；若将R分解为如下两个关系模式 （16） ，则分解后的关系模式保持函数依赖。</p>","analyze":"<p>CE只在函数依赖集F的左部，且能推出属性集U。所以<img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/9a23bfc66d53279790cc9c6c134e1930.png?x-oss-process=style/ruankaodaren\" title=\"9a23bfc66d53279790cc9c6c134e1930.png\" alt=\"image.png\" width=\"87\" height=\"19\"/>，CE必为R的候选码。</p><p>A选项中，R1(A,B,C)和R2（D,E,G）分别得到函数依赖集F1=｛A→B,C→A｝、F2=φ，F1+F2≠F，则分解后的关系模式不能保持函数依赖。</p><p>B选项中，R1(B,C,D,E)和R2（A,E,G）分别得到函数依赖集F1=φ、F2=｛AE→G｝，F1+F2≠F，则分解后的关系模式不能保持函数依赖。</p><p>C选项中，R1(B,C,D)和R2（A,E,G）分别得到函数依赖集F1=φ、F2=｛AE→G｝，F1+F2≠F，则分解后的关系模式不能保持函数依赖。</p><p>D选项中，R1(A,B,C,D)和R2（A,E,G）分别得到函数依赖集F1=｛A→B,A→D,C→A｝、F2=｛AE→G｝，F1+F2=F，则分解后的关系模式能保持函数依赖。</p><p>参考答案：（15）D；（16）D</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930290454712321"],"itemList":[{"id":"794930290408574977","questionId":"794930288198176769","content":"R1(A,B,C)和R2(D,E,G)","answer":0,"chooseValue":"A"},{"id":"794930290425352193","questionId":"794930288198176769","content":"R1(B,C,D,E)和R2(A,E,G)","answer":0,"chooseValue":"B"},{"id":"794930290442129409","questionId":"794930288198176769","content":"R1(B,C,D)和R2(A,E,G)","answer":0,"chooseValue":"C"},{"id":"794930290454712321","questionId":"794930288198176769","content":"R1(A,B,C,D)和R2(A,E,G)","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930236843118593","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>以下媒体中（）是表示媒体，（）是表现媒体。</p>","analyze":"<p>表示媒体是为了加工、处理和传输感觉媒体而人为研究、构造出来的一种媒体，它有各种编码方式，如：文本编码、图像编码和声音编码等。</p><p>表现媒体是指进行信息输入和输出的媒体，如：键盘、鼠标、扫捕仪、话筒和摄像机等输入媒体以及显示器、打印机和扬声器等输出媒体。</p><p>感觉媒体是指直接作用于人的感觉器官，使人产生直接感觉的媒体，如：引起听觉反应的声音，引起视觉反应的文本、图形和图像等。</p><p>存储媒体是指用于存储表示媒体的物理介质，如：硬盘、软盘、光盘和胶卷等。</p><p>传输媒体是指用于存储表示媒体的物理介质，如：电缆和光缆等。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930238734749697"],"itemList":[{"id":"794930238684418049","questionId":"794930236843118593","content":"声音","answer":0,"chooseValue":"A"},{"id":"794930238701195265","questionId":"794930236843118593","content":"声音编码","answer":0,"chooseValue":"B"},{"id":"794930238717972481","questionId":"794930236843118593","content":"超声波","answer":0,"chooseValue":"C"},{"id":"794930238734749697","questionId":"794930236843118593","content":"喇叭","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930275732705281","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks, RAID）机制中共分 （8） 级别， RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中， （9） 是由单一的磁盘负责冗余和数据校验； （10） 由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用； （11） 兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。","analyze":"<p>RAID等级分为8个级别。RAID 0是无冗余和无校验的数据分块；RAID 1每一个工作盘都有其对应的镜像盘，磁盘空间利用率为50%；RAID3由单一的独立磁盘负责冗余和数据校验；RAID5由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用；RAID 10采用RAID0和RAID1组合而成，兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。</p><p>参考答案：（8）B；（9）D；（10）D；（11）A</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930277666279425"],"itemList":[{"id":"794930277624336385","questionId":"794930275732705281","content":"RAID 0级","answer":0,"chooseValue":"A"},{"id":"794930277636919297","questionId":"794930275732705281","content":"RAID 1 级","answer":0,"chooseValue":"B"},{"id":"794930277653696513","questionId":"794930275732705281","content":"RAID 2 级","answer":0,"chooseValue":"C"},{"id":"794930277666279425","questionId":"794930275732705281","content":"RAID 3 级","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930156975181825","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>某计算机系统的CPU主频为2.8GHz。某应用程序包括3类指令，各类指令的CPI（执行每条指令所需要的时钟周期数）及指令比例如下表所示。执行该应用程序时的平均CPI为（2）；运算速度用MIPS 表示，约为（3）。</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/09534555a2705875621ccd5a5e198cb0.jpg?x-oss-process=style/ruankaodaren\" title=\"09534555a2705875621ccd5a5e198cb0.jpg\" alt=\"1.jpg\"/></p><br/>","analyze":"<p>平均执行周期数（Cycle Per Instruction，CPI ）是指CPU每执行一条指令所需的时钟周期数。</p><p>本题已经给出了三条指令的CPI，那么平均CPI为：4*35%+3*45%+6*20%=4</p><p>每秒百万级指令执行数量（Million Instructions Per Second，MIPS）＝指令条数/（执行时间×106）＝主频/CPI=2.8G/4=700MIPS。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930158829064193"],"itemList":[{"id":"794930158829064193","questionId":"794930156975181825","content":"700","answer":1,"chooseValue":"A"},{"id":"794930158854230017","questionId":"794930156975181825","content":"800","answer":0,"chooseValue":"B"},{"id":"794930158883590145","questionId":"794930156975181825","content":"930","answer":0,"chooseValue":"C"},{"id":"794930158908755969","questionId":"794930156975181825","content":"1100","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930248125796353","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p><p>计算机系统中， （10） 方式是根据所访问的内容来决定要访问的存储单元，常用在 （11） 存储器中。</p>","analyze":"相联存取是一种随机存取，但是选择某一单元进行读写是取决于其内容而不是其地址。与普通的随机存取方式一样，每个单元都有自己的读写装置，读写时间也是一个常数。使用相联存取方式，可以对所有的存储单元的特定位进行比较，选择符合条件的单元进行访问。为了提高地址映射的速度，Cache采取相联存取的方式。","multi":0,"questionType":1,"answer":"B","chooseItem":["794930250004844545"],"itemList":[{"id":"794930249988067329","questionId":"794930248125796353","content":"DRAM","answer":0,"chooseValue":"A"},{"id":"794930250004844545","questionId":"794930248125796353","content":"Cache","answer":1,"chooseValue":"B"},{"id":"794930250021621761","questionId":"794930248125796353","content":"Flash","answer":0,"chooseValue":"C"},{"id":"794930250038398977","questionId":"794930248125796353","content":"CD-ROM","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930162696212481","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p>在计算机的浮点数表示中，主要影响数值表示范围的是 （11），影响计算精度的是 （12）。","analyze":"<p>在计算机中浮点数的表示形式是：</p><p><img style=\"max-width:100%;height:auto\" src=\"https://image.chaiding.com/ruankao/492146023efb5393735a90bf41ed5262.jpg?x-oss-process=style/ruankaodaren\" title=\"492146023efb5393735a90bf41ed5262.jpg\" alt=\"1.jpg\"/></p><p>其中F是浮点数的尾数，E为浮点数的阶码。影响数值表示范围的是阶码的位数，尾数的位数影响计算的精度。</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930164554289153"],"itemList":[{"id":"794930164554289153","questionId":"794930162696212481","content":"尾数的位数","answer":1,"chooseValue":"A"},{"id":"794930164571066369","questionId":"794930162696212481","content":"规格化的方法","answer":0,"chooseValue":"B"},{"id":"794930164587843585","questionId":"794930162696212481","content":"阶码的位数","answer":0,"chooseValue":"C"},{"id":"794930164604620801","questionId":"794930162696212481","content":"尾数下溢的处理","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930151371591681","title":"<p><strong>请作答第<span style=\"color: red\">2</span>空。</strong></p>以下媒体中（8）是表示媒体，（9）是表现媒体。","analyze":"<p>表示媒体是为了加工、处理和传输感觉媒体而人为研究、构造出来的一种媒体，它有各种编码方式，如：文本编码、图像编码和声音编码等。</p><p>表现媒体是指进行信息输入和输出的媒体，如：键盘、鼠标、扫捕仪、话筒和摄像机等输入媒体以及显示器、打印机和扬声器等输出媒体。</p><p>感觉媒体是指直接作用于人的感觉器官，使人产生直接感觉的媒体，如：引起听觉反应的声音，引起视觉反应的文本、图形和图像等。</p><p>存储媒体是指用于存储表示媒体的物理介质，如：硬盘、软盘、光盘和胶卷等。</p><p>传输媒体是指用于存储表示媒体的物理介质，如：电缆和光缆等。</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930153259028481"],"itemList":[{"id":"794930153212891137","questionId":"794930151371591681","content":"声音","answer":0,"chooseValue":"A"},{"id":"794930153229668353","questionId":"794930151371591681","content":"超声波","answer":0,"chooseValue":"B"},{"id":"794930153246445569","questionId":"794930151371591681","content":"声音编码","answer":0,"chooseValue":"C"},{"id":"794930153259028481","questionId":"794930151371591681","content":"喇叭","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930278584832001","title":"<p><strong>请作答第<span style=\"color: red\">3</span>空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks, RAID）机制中共分 （8） 级别， RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中， （9） 是由单一的磁盘负责冗余和数据校验； （10） 由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用； （11） 兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。","analyze":"<p>RAID等级分为8个级别。RAID 0是无冗余和无校验的数据分块；RAID 1每一个工作盘都有其对应的镜像盘，磁盘空间利用率为50%；RAID3由单一的独立磁盘负责冗余和数据校验；RAID5由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用；RAID 10采用RAID0和RAID1组合而成，兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。</p><p>参考答案：（8）B；（9）D；（10）D；（11）A</p>","multi":0,"questionType":1,"answer":"D","chooseItem":["794930280489046017"],"itemList":[{"id":"794930280438714369","questionId":"794930278584832001","content":"RAID 4级","answer":0,"chooseValue":"A"},{"id":"794930280455491585","questionId":"794930278584832001","content":"RAID 1 级","answer":0,"chooseValue":"B"},{"id":"794930280472268801","questionId":"794930278584832001","content":"RAID 3 级","answer":0,"chooseValue":"C"},{"id":"794930280489046017","questionId":"794930278584832001","content":"RAID 5级","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"794930281550204929","title":"<p><strong>请作答第<span style=\"color: red\">4</span>空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks, RAID）机制中共分 （8） 级别， RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中， （9） 是由单一的磁盘负责冗余和数据校验； （10） 由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用； （11） 兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。","analyze":"<p>RAID等级分为8个级别。RAID 0是无冗余和无校验的数据分块；RAID 1每一个工作盘都有其对应的镜像盘，磁盘空间利用率为50%；RAID3由单一的独立磁盘负责冗余和数据校验；RAID5由每个磁盘轮流负责数据校验，有良好的读写性能和容错能力，因此得到了广泛应用；RAID 10采用RAID0和RAID1组合而成，兼顾了冗余备份与极高的读写性能，磁盘数量为4的倍数。</p><p>参考答案：（8）B；（9）D；（10）D；（11）A</p>","multi":0,"questionType":1,"answer":"A","chooseItem":["794930283752214529"],"itemList":[{"id":"794930283752214529","questionId":"794930281550204929","content":"RAID 10级","answer":1,"chooseValue":"A"},{"id":"794930283768991745","questionId":"794930281550204929","content":"RAID 5 级","answer":0,"chooseValue":"B"},{"id":"794930283785768961","questionId":"794930281550204929","content":"RAID 4 级","answer":0,"chooseValue":"C"},{"id":"794930283802546177","questionId":"794930281550204929","content":"RAID 3 级","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237167100710913","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>Flynn分类法根据计算机在执行程序的过程中（14）的不同组合，将计算机分为4类。当前主流的多核计算机属于（15）计算机。","analyze":"本题考查计算机系统基础知识。<br>Flynn于1972年提出计算平台分类法主要根据指令流和数据流来分类，分为四类：<br>①单指令流单数据流机器(SISD)<br>SISD机器是一种传统的串行计算机，其硬件不支持任何形式的并行计算，所有的指令都是串行执行，并且在某个时钟周期内，CPU只能处理一个数据流。早期的计算机都是SISD机器。<br>②单指令流多数据流机器(SIMD)<br>SIMD是采用一个指令流处理多个数据流。这类机器在数字信号处理、图像处理，以及多媒体信息处理等领域非常有效。<br>Intel处理器实现的MMXTM、SSE(StreamingSIMDExtensions)、SSE2及SSE3扩展指令集，都能在单个时钟周期内处理多个数据单元。也就是说人们现在用的单核计算机基本上都属于SIMD机器。<br>③多指令流单数据流机器(MISD)<br>MISD是采用多个指令流来处理单个数据流。在实际情况中，采用多指令流处理多数据流才是更有效的方法，因此MISD只是作为理论模型出现，没有实际应用。<br>④多指令流多数据流机器(MIMD)<br>MIMD机器可以同时执行多个指令流，这些指令流分别对不同数据流进行操作。最新的多核计算平台就属于MIMD的范畴，例如Intel和AMD的双核处理器。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237168048623617"],"itemList":[{"id":"796237168048623617","questionId":"796237167100710913","content":" 指令流和数据流","answer":1,"chooseValue":"A"},{"id":"796237168077983745","questionId":"796237167100710913","content":" 数据流和控制流","answer":0,"chooseValue":"B"},{"id":"796237168094760961","questionId":"796237167100710913","content":" 指令流和控制流","answer":0,"chooseValue":"C"},{"id":"796237168107343873","questionId":"796237167100710913","content":" 数据流和总线带宽","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237266757373953","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>某计算机系统采用4级流水线结构执行指令，设每条指令的执行由取指令<img src=\"https://image.chaiding.com/ruankao/14f1055fa09d0d235bae62f442a30fa2.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">分析指令<img src=\"https://image.chaiding.com/ruankao/73e04bdbd38cafd3d228396dd4dd5356.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">、取操作数<img src=\"https://image.chaiding.com/ruankao/8f312edec0fb803bf3e62c4069395889.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">、运算并保存结果<img src=\"https://image.chaiding.com/ruankao/00b1f67e1f9f0b52a437d82ed4fd91e6.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">组成（注：括号中是指令执行周期），并分别用4个子部件完成，该流水线的最大吞吐率为（14）；若连续向流水线输入5条指令，则该流水线的加速比为（15）。","analyze":"本题考查计算机系统中流水线基础知识。<br>流水线的吞吐率（ThoughtPut rate, TP)是指单位时间内流水线所完成的任务数量或输出的结果数量。计算流水线吞吐率TP的基本公式为：<br> <input height=\"39\" src=\"https://image.chaiding.com/ruankao/2d990b8531a37c8311be857dffb90fed.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"55\" longdesc=\"undefined\"><br>其中n是任务数，<input height=\"22\" src=\"https://image.chaiding.com/ruankao/3c68569d15edd462a28f9bd2449ac938.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"20\">是处理完n个任务所用的时间。<br>当流水线各段执行时间均相等（为<input height=\"17\" src=\"https://image.chaiding.com/ruankao/485f4523a6323575d938c7a02c09e428.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"20\" longdesc=\"undefined\">),输入连续n个任务的一条k段线性流水线<br>的实际吞吐率为<input height=\"19\" src=\"https://image.chaiding.com/ruankao/6b7850b6682eb066b331e339576426b3.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"65\">，最大吞吐率为<input height=\"28\" src=\"https://image.chaiding.com/ruankao/910a8c3912321515651b966c2601df1f.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"55\">。<br>当流水线中各个流水段的执行时间不完全相等时，流水线的最大吞吐率与实际吞吐率主要是由流水线中执行时间最长的那个流水段来决定的，这个流水段就成了整个流水线的“瓶颈”。根据题目说明，这种情况下的最大吞吐率<input height=\"28\" src=\"https://image.chaiding.com/ruankao/ed523b560b13cc4e5e80fb00568489ce.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"55\">。<br>流水线的加速比定义为完成一批任务不使用流水线所用的时间与使用流水线所用的时间之比。<br>对于本问题，不使用流水线完成5条指令的时间为<input height=\"20\" src=\"https://image.chaiding.com/ruankao/0ef2d462a4da76aef9785079f75f06fc.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"45\">，使用流水线所用的时间为<input height=\"13\" src=\"https://image.chaiding.com/ruankao/b3d0acce0d0bb29c64aea8807d7f6924.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"55\">，，因此加速比为2:1。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237267755618305"],"itemList":[{"id":"796237267709480961","questionId":"796237266757373953","content":" 1","answer":0,"chooseValue":"A"},{"id":"796237267730452481","questionId":"796237266757373953","content":" <img alt=\"\" width=\"29\" height=\"42\" src=\"https://image.chaiding.com/ruankao/b95bac4af37ae14b944a72c3f08945bc.jpg?x-oss-process=style/ruankaodaren\">","answer":0,"chooseValue":"B"},{"id":"796237267755618305","questionId":"796237266757373953","content":" <img alt=\"\" width=\"37\" height=\"40\" src=\"https://image.chaiding.com/ruankao/284d3ac1d7528befba635d5425e4c3f2.jpg?x-oss-process=style/ruankaodaren\">","answer":1,"chooseValue":"C"},{"id":"796237267780784129","questionId":"796237266757373953","content":" <img alt=\"\" width=\"30\" height=\"38\" src=\"https://image.chaiding.com/ruankao/cf0b257d39cd51ccd9615f857b27d032.jpg?x-oss-process=style/ruankaodaren\">","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237314203340801","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>设每条指令由取指、分析、执行3个子部件完成，并且每个子部件的执行时间均为△t。若采用常规标量单流水线处理机（即该处理机的度为1），连续执行16条指令，则共耗时（14） △t。若采用度为4的超标量流水线处理机，连续执行上述16条指令，则共耗时（15）△t。","analyze":"本题考查系统流水线知识。<br>采用常规标量单流水线处理机（即该处理机的度m=l)，连续执行16条指令的时空图如下图所示，从中可以看出，连续执行16条指令所需时间为18At。<br><img alt=\"\" width=\"471\" height=\"151\" src=\"https://image.chaiding.com/ruankao/b63f94a4d36b00abc07e97ec759d48d5.jpg?x-oss-process=style/ruankaodaren\"><br>当釆用度m为4的超标量流水线处理机，连续执行上述16条指令时，时空图如下所示。从中可以看出，连续执行16条指令所需时间为6At。<br><img width=\"316\" height=\"305\" alt=\"\" src=\"https://image.chaiding.com/ruankao/79aac6657ff483be5bc3baa69095f949.jpg?x-oss-process=style/ruankaodaren\">","multi":0,"questionType":1,"answer":"C","chooseItem":["796237315126087681"],"itemList":[{"id":"796237315096727553","questionId":"796237314203340801","content":" 4","answer":0,"chooseValue":"A"},{"id":"796237315113504769","questionId":"796237314203340801","content":" 5","answer":0,"chooseValue":"B"},{"id":"796237315126087681","questionId":"796237314203340801","content":" 6","answer":1,"chooseValue":"C"},{"id":"796237315142864897","questionId":"796237314203340801","content":" 8","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237164114366465","title":"DMA工作方式是在（17）之间建立直接的数据通路。","analyze":"本题考査计算机系统基础知识。<br>DMA方式（Direct Memory Access，也称为成组数据传送方式)，有时也称为直接内存操作。一个设备接口试图通过总线直接向另一个设备发送数据(一般是大批量的数据），它会先向CPU发送DMA请求信号，向CPU提出接管总线控制权的总线请求，CPU收到该信号后，在当前的总线周期结束后，会按DMA信号的优先级和提出DMA请求的先后顺序响应DMA信号。CPU对某个设备接口响应DMA请求时，会让出总线控制权，于是在DMA控制器的管理下，外设和存储器直接进行数据交换，而不需CPU干预。数据传送完毕后，设备接口会向CPU发送DMA结束信号，交还总线控制权。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237165087444993"],"itemList":[{"id":"796237165037113345","questionId":"796237164114366465","content":" CPU与外设","answer":0,"chooseValue":"A"},{"id":"796237165058084865","questionId":"796237164114366465","content":" CPU与主存","answer":0,"chooseValue":"B"},{"id":"796237165087444993","questionId":"796237164114366465","content":" 主存与外设","answer":1,"chooseValue":"C"},{"id":"796237165112610817","questionId":"796237164114366465","content":" 外设与外设","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237250349256705","title":"按照Cache地址映像的块冲突概率，从高到低排列的是（15）。","analyze":"本题考查计算机系统基础知识。<br>直接映像是指在进行映像的工作时，规定各区中的某一信息块只能映像到Cache中的一个固定的信息块中，即主存中的第0块映像到Cache的第0个块，第1块映像到Cache 的第1块，以此类推。<br>全相联映像是指主存中的每一个字块可映像到Cache任何一个字块位置上。<br>组相联映像方式是直接映像和全相联映像的一种折衷方案。这种方法将存储空间分为若干组，各组之间是直接映像，而组内各块之间则是全相联映像。<br>显然，进行地址映像时，直接映像方式下冲突概率最高，全相联映像方式下冲突概率最低。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237251427192833"],"itemList":[{"id":"796237251406221313","questionId":"796237250349256705","content":" 全相联映像→直接映像→组相联映像","answer":0,"chooseValue":"A"},{"id":"796237251427192833","questionId":"796237250349256705","content":" 直接映像→组相联映像→全相联映像","answer":1,"chooseValue":"B"},{"id":"796237251448164353","questionId":"796237250349256705","content":" 组相联映像→全相联映像→直接映像","answer":0,"chooseValue":"C"},{"id":"796237251464941569","questionId":"796237250349256705","content":" 直接映像→全相联映像→组相联映像","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237216627052545","title":"关于大规模并行处理器MPP，以下说法不正确的是（）。","analyze":"本题考查计算机系统基础知识。<br>大规模并行处理MPP(Massively Parallel Processing)系统是指使用专用通信网络构成的大型多机系统。每个节点都是一个完全独立的计算机，节点间采用分布式存储器结构，节点间通信采用消息机制，可包容多处理器系统。<br>大多数MPP系统使用标准的CPU作为它们的处理器，常用的有Intel Pentium系列、Sun UltraSPARC和IBM PowerPC等。MPP系统使用高性能的定制的高速互连网络及网络接口，可以在低延迟和高带宽的条件下传递消息。MPP是一种异步的分布式存储器结构的MIMD系统，它的程序有多个进程，分布在各个微处理器上，每个进程有自己独立的地址空间，进程之间以消息传递进行相互通信。大规模的MPP系统使用特殊的硬件和软件来监控系统、检测错误并从错误中平滑地恢复。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237217616908289"],"itemList":[{"id":"796237217562382337","questionId":"796237216627052545","content":" 大多数MPP系统使用标准的CPU作为它们的处理器","answer":0,"chooseValue":"A"},{"id":"796237217616908289","questionId":"796237216627052545","content":" 其互连网络通常采用商用的以太网实现","answer":1,"chooseValue":"B"},{"id":"796237217663045633","questionId":"796237216627052545","content":" 是一种异步的分布式存储器结构的MIMD系统","answer":0,"chooseValue":"C"},{"id":"796237217684017153","questionId":"796237216627052545","content":" 使用特殊的硬件和软件来监控系统、检测错误并从错误中平滑地恢复","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237311317659649","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>设每条指令由取指、分析、执行3个子部件完成，并且每个子部件的执行时间均为△t。若采用常规标量单流水线处理机（即该处理机的度为1），连续执行16条指令，则共耗时（14） △t。若采用度为4的超标量流水线处理机，连续执行上述16条指令，则共耗时（15）△t。","analyze":"本题考查系统流水线知识。<br>采用常规标量单流水线处理机（即该处理机的度m=l)，连续执行16条指令的时空图如下图所示，从中可以看出，连续执行16条指令所需时间为18At。<br><img alt=\"\" width=\"471\" height=\"151\" src=\"https://image.chaiding.com/ruankao/e74d9823b885b719dbeb2ba49ec4d20e.jpg?x-oss-process=style/ruankaodaren\"><br>当釆用度m为4的超标量流水线处理机，连续执行上述16条指令时，时空图如下所示。从中可以看出，连续执行16条指令所需时间为6At。<br><img alt=\"\" width=\"316\" height=\"305\" src=\"https://image.chaiding.com/ruankao/fb140acff0fbf81b20ca74f60b2e047b.jpg?x-oss-process=style/ruankaodaren\">","multi":0,"questionType":1,"answer":"B","chooseItem":["796237312240406529"],"itemList":[{"id":"796237312215240705","questionId":"796237311317659649","content":" 16","answer":0,"chooseValue":"A"},{"id":"796237312240406529","questionId":"796237311317659649","content":" 18","answer":1,"chooseValue":"B"},{"id":"796237312265572353","questionId":"796237311317659649","content":" 32","answer":0,"chooseValue":"C"},{"id":"796237312286543873","questionId":"796237311317659649","content":" 48","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237260835016705","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>某计算机系统的结构如下图所示，按照弗林（Michael J.Flynn）提出的分类法，它属于（17），其中，PU<sub>i</sub>(i=1,…,n)为处理单元，CU为控制部件，MM<sub>j</sub>(j=1,…,n)为存储部件。该计算机（18）。<br><img alt=\"\" width=\"274\" height=\"176\" src=\"https://image.chaiding.com/ruankao/5b1f4b86e51ed3980e4ce0cf35e4ef39.jpg?x-oss-process=style/ruankaodaren\">","analyze":" 本题考查计算机系统结构的基本概念。<br> 1966年，MJ.Flynn根据指令流(Instruction Stream机器执行指令序列）、数据流(Data Stream指令流调用的数据序列）、多倍性（Multiplicity在系统结构的流程瓶颈上同时执行的指令或数据可能最大个数）将系统结构分成单指令流单数据流（SISD）、单指令流多数据流（SIMD）、多指令流单数据流（MISD)、多指令流多数据流（MIMD）。计算机系统中开发并行性的方法有资源重复、时间重叠和资源共享3种基本途径。题中的计算机有一个控制单元，所以是单指令流；多个处理和存储部件，是多数据流，因此，属于单指令流多数据流计算机（SIMD）。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237261774540801"],"itemList":[{"id":"796237261753569281","questionId":"796237260835016705","content":" 单指令流单数据流计算机(SISD)","answer":0,"chooseValue":"A"},{"id":"796237261774540801","questionId":"796237260835016705","content":" 单指令流多数据流计算机(SIMD)","answer":1,"chooseValue":"B"},{"id":"796237261795512321","questionId":"796237260835016705","content":" 多指令流单数据流计算机(MISD)","answer":0,"chooseValue":"C"},{"id":"796237261820678145","questionId":"796237260835016705","content":" 多指令流多数据流计算机(MIMD)","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237269798244353","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>某计算机系统采用4级流水线结构执行指令，设每条指令的执行由取指令<img src=\"https://image.chaiding.com/ruankao/14f1055fa09d0d235bae62f442a30fa2.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">分析指令<img src=\"https://image.chaiding.com/ruankao/73e04bdbd38cafd3d228396dd4dd5356.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">、取操作数<img src=\"https://image.chaiding.com/ruankao/8f312edec0fb803bf3e62c4069395889.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">、运算并保存结果<img src=\"https://image.chaiding.com/ruankao/00b1f67e1f9f0b52a437d82ed4fd91e6.jpg?x-oss-process=style/ruankaodaren\" width=\"45\">组成（注：括号中是指令执行周期），并分别用4个子部件完成，该流水线的最大吞吐率为（14）；若连续向流水线输入5条指令，则该流水线的加速比为（15）。","analyze":"本题考查计算机系统中流水线基础知识。<br>流水线的吞吐率（ThoughtPut rate, TP)是指单位时间内流水线所完成的任务数量或输出的结果数量。计算流水线吞吐率TP的基本公式为：<br><input height=\"39\" src=\"https://image.chaiding.com/ruankao/312041a6f6ccbcbf32f976aeb60e0017.jpg?x-oss-process=style/ruankaodaren\" type=\"image\" width=\"60\" longdesc=\"undefined\"><br>其中n是任务数，是处理完n个任务所用的时间。<br>当流水线各段执行时间均相等（为<img alt=\"\" width=\"20\" height=\"19\" src=\"https://image.chaiding.com/ruankao/240f99b662c6f97263768de3434a0abd.jpg?x-oss-process=style/ruankaodaren\">),输入连续n个任务的一条k段线性流水线<br>的实际吞吐率为<img alt=\"\" width=\"65\" height=\"19\" src=\"https://image.chaiding.com/ruankao/198733f54c6479235e405bc33c2c65bb.jpg?x-oss-process=style/ruankaodaren\">，最大吞吐率为<img alt=\"\" width=\"50\" height=\"25\" src=\"https://image.chaiding.com/ruankao/e44ada073c27e1883687c8874f7949f2.jpg?x-oss-process=style/ruankaodaren\">。<br>当流水线中各个流水段的执行时间不完全相等时，流水线的最大吞吐率与实际吞吐率主要是由流水线中执行时间最长的那个流水段来决定的，这个流水段就成了整个流水线的“瓶颈”。根据题目说明，这种情况下的最大吞吐率。<br>流水线的加速比定义为完成一批任务不使用流水线所用的时间与使用流水线所用的时间之比。<br>对于本问题，不使用流水线完成5条指令的时间为<img alt=\"\" width=\"35\" height=\"17\" src=\"https://image.chaiding.com/ruankao/82d63c8c443f01f8dbd403b85aff2dfd.jpg?x-oss-process=style/ruankaodaren\">，使用流水线所用的时间为<img alt=\"\" width=\"55\" height=\"17\" src=\"https://image.chaiding.com/ruankao/8e5f83746b21158a0955983d56a12f14.jpg?x-oss-process=style/ruankaodaren\">，因此加速比为2:1。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237270771322881"],"itemList":[{"id":"796237270750351361","questionId":"796237269798244353","content":" 1:1","answer":0,"chooseValue":"A"},{"id":"796237270771322881","questionId":"796237269798244353","content":" 2:1","answer":1,"chooseValue":"B"},{"id":"796237270788100097","questionId":"796237269798244353","content":" 8:3","answer":0,"chooseValue":"C"},{"id":"796237270809071617","questionId":"796237269798244353","content":" 3:8","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237222603935745","title":"在Cache-主存层次结构中，主存单元到Cache单元的地址转换由(17)完成。","analyze":"本题考查存储系统知识。<br>在由Cache-主存构成的层次式存储系统中，为了提高地址转换速度，主存单元到Cache单元的地址转换采用硬件完成。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237223501516801"],"itemList":[{"id":"796237223501516801","questionId":"796237222603935745","content":" 硬件","answer":1,"chooseValue":"A"},{"id":"796237223518294017","questionId":"796237222603935745","content":" 寻址方式","answer":0,"chooseValue":"B"},{"id":"796237223535071233","questionId":"796237222603935745","content":" 软件和少量的辅助硬件","answer":0,"chooseValue":"C"},{"id":"796237223547654145","questionId":"796237222603935745","content":" 微程序","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237205457620993","title":"使用多处理机系统的主要目的是实现（14）代码的并行性。","analyze":"本题考查计算机系统基础知识。<br>广义上说，使用多台计算机协同工作来完成所要求的任务的计算机系统都是多处理机系统。传统的狭义多处理机系统是指利用系统内的多个CPU并行执行用户多个程序，以提高系统的吞吐量或用来进行冗余操作以提高系统的可靠性。<br>在多处理机系统中，提高程序并行性的关键，是把任务分解成足够多的可同时操作的进程。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237206430699521"],"itemList":[{"id":"796237206367784961","questionId":"796237205457620993","content":" 操作级和指令级","answer":0,"chooseValue":"A"},{"id":"796237206401339393","questionId":"796237205457620993","content":" 指令级和作业级","answer":0,"chooseValue":"B"},{"id":"796237206430699521","questionId":"796237205457620993","content":" 作业级和任务级","answer":1,"chooseValue":"C"},{"id":"796237206460059649","questionId":"796237205457620993","content":" 任务级和指令级","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237236914900993","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>在计算机系统中，若一个存储单元被访问，这个存储单元有可能很快会再被访问，该特性被称为（16）；这个存储单元及其邻近的存储单元有可能很快会再被访问，该特性被称为（17）。","analyze":"局部性原理是指在指定时间内，程序趋于在有限的内存区域内重复访问。通常将局部性分为空间局部性和时间局部性。空间局部性是指已访问过的内存地址附近的位置很可能被连续访问。时间局部性是指已访问过的内存地址在较短的时间内还可能被多次访问。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237237879590913"],"itemList":[{"id":"796237237854425089","questionId":"796237236914900993","content":" 程序局部性","answer":0,"chooseValue":"A"},{"id":"796237237879590913","questionId":"796237236914900993","content":" 空间局部性","answer":1,"chooseValue":"B"},{"id":"796237237904756737","questionId":"796237236914900993","content":" 时间局部性","answer":0,"chooseValue":"C"},{"id":"796237237925728257","questionId":"796237236914900993","content":" 数据局部性","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237228475961345","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>在磁盘调度管理中，应先进行移臂调度，再进行旋转调度。若磁盘移动臂位于22号柱面上，进程的请求序列如下表所示。若采用最短移臂调度算法，则系统的响应序列应为（47）,其平均移臂距离为（48）。<br><img alt=\"\" width=\"412\" height=\"220\" src=\"https://image.chaiding.com/ruankao/153edb40acdf6fccc34403fb4633c4d1.jpg?x-oss-process=style/ruankaodaren\">","analyze":"平均移臂距离等于移臂总距离除移臂次数，即<br>平均移臂距离=((25-22)+(25-18)+(40-18)+(45-40))/9≈4.11","multi":0,"questionType":1,"answer":"A","chooseItem":["796237229436456961"],"itemList":[{"id":"796237229436456961","questionId":"796237228475961345","content":" 4.11","answer":1,"chooseValue":"A"},{"id":"796237229478400001","questionId":"796237228475961345","content":" 5.56","answer":0,"chooseValue":"B"},{"id":"796237229516148737","questionId":"796237228475961345","content":" 12.5","answer":0,"chooseValue":"C"},{"id":"796237229549703169","questionId":"796237228475961345","content":" 13.22","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237272801366017","title":"某计算机系统采用集中式总线仲裁方式，各个主设备得到总线使用权的机会基本相等，则该系统采用的总线仲裁方式（）。<br>①菊花链式查询方式 ②计数器定时查询（轮询）方式 ③独立请求方式","analyze":"本题考查计算机系统基础知识。<br>共享总线上允许有多个主设备和从设备，可能会有多个主设备同时要求使用总线的情况(执行操作都是由主设备发起的(，为了防止总线竞争，共享总线上某一时刻只允许-个主设备使用总线。这就需要总线仲裁。集中式仲裁釆用一个中央总线仲裁器(总线控制器)，由它来决定总线上同时提出使用请求的主设备谁可以获得总线使用权，主要有三种方案：菊花链式查询方式，计数器定时查询(轮询(方式和独立请求方式。<br>菊花链式查询方式中，设备的先后连接顺序决定了其优先级。而计数器定时查询(轮询(方式及独立请求方式中，可以做到各个主设备得到总线使用权的机会基本相等。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237273736695809"],"itemList":[{"id":"796237273707335681","questionId":"796237272801366017","content":" 可能是③，不可能是①或②","answer":0,"chooseValue":"A"},{"id":"796237273736695809","questionId":"796237272801366017","content":" 可能是②或③，不可能是①","answer":1,"chooseValue":"B"},{"id":"796237273766055937","questionId":"796237272801366017","content":" 可能是②，不可能是①或③","answer":0,"chooseValue":"C"},{"id":"796237273791221761","questionId":"796237272801366017","content":" 可能是①、②或③","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237170057695233","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>Flynn分类法根据计算机在执行程序的过程中（14）的不同组合，将计算机分为4类。当前主流的多核计算机属于（15）计算机。","analyze":"本题考查计算机系统基础知识。<br>Flynn于1972年提出计算平台分类法主要根据指令流和数据流来分类，分为四类：<br>①单指令流单数据流机器(SISD)<br>SISD机器是一种传统的串行计算机，其硬件不支持任何形式的并行计算，所有的指令都是串行执行，并且在某个时钟周期内，CPU只能处理一个数据流。早期的计算机都是SISD机器。<br>②单指令流多数据流机器(SIMD)<br>SIMD是采用一个指令流处理多个数据流。这类机器在数字信号处理、图像处理，以及多媒体信息处理等领域非常有效。<br>Intel处理器实现的MMXTM、SSE(Streaming SIMD Extensions)、SSE2及SSE3扩展指令集，都能在单个时钟周期内处理多个数据单元。也就是说人们现在用的单核计算机基本上都属于SIMD机器。<br>③多指令流单数据流机器(MISD)<br>MISD是采用多个指令流来处理单个数据流。在实际情况中，采用多指令流处理多数据流才是更有效的方法，因此MISD只是作为理论模型出现，没有实际应用。<br>④多指令流多数据流机器(MIMD)<br>MIMD机器可以同时执行多个指令流，这些指令流分别对不同数据流进行操作。最新的多核计算平台就属于MIMD的范畴，例如Intel和AMD的双核处理器。","multi":0,"questionType":1,"answer":"D","chooseItem":["796237171060133889"],"itemList":[{"id":"796237170980442113","questionId":"796237170057695233","content":" SISD","answer":0,"chooseValue":"A"},{"id":"796237171009802241","questionId":"796237170057695233","content":" SIMD","answer":0,"chooseValue":"B"},{"id":"796237171034968065","questionId":"796237170057695233","content":" MISD","answer":0,"chooseValue":"C"},{"id":"796237171060133889","questionId":"796237170057695233","content":" MIMD","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237188009316353","title":"以下关于在I/O设备与主机间交换数据的叙述中，错误的是（16）。","analyze":"本题考查计算机系统基础知识。<br>常用的I/O设备和CPU之间数据传送控制方式有4种，分别为程序直接控制方式、中断控制方式、DMA方式和通道方式。<br>程序直接控制方式和中断控制方式都只适用于简单的、外设很少的计算机系统，因为程序直接控制方式耗费大量的CPU时间，而且无法检测发现设备或其他硬件产生的错误，设备与CPU、设备与设备只能串行工作。中断控制方式虽然在某种程度上解决了上述问题，但由于中断次数多，因而CPU仍需要花费较多的时间处理中断，而且能够并行操作的设备台数也受到中断处理时间的限制，中断次数增多也导致数据丢失。DMA方式和通道方式较好地解决了上述问题。这两种方式采用了外设和内存直接交换数据的方 式。只有在一段数据传送结束时，才发出中断信号要求CPU做善后处理，从而大大减少了CPU的工作负担。DMA方式与通道控制方式的区别是，DMA方式要求CPU执行设备驱动程序来启动设备，给出存放数据的内存起始地址以及操作方式和传送字节长度等； 而通道控制方式则是在CPU发出I/O启动命令之后，由通道指令来完成这些工作。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237189015949313"],"itemList":[{"id":"796237188965617665","questionId":"796237188009316353","content":" 中断方式下，CPU需要执行程序来实现数据传送","answer":0,"chooseValue":"A"},{"id":"796237188990783489","questionId":"796237188009316353","content":" 中断方式和DMA方式下，CPU与I/O设备都可同步工作","answer":0,"chooseValue":"B"},{"id":"796237189015949313","questionId":"796237188009316353","content":" 中断方式和DMA方式相比，快速I/O设备更适合釆用中断方式传递数据","answer":1,"chooseValue":"C"},{"id":"796237189036920833","questionId":"796237188009316353","content":" 若同时接到DMA请求和中断请求，CPU优先响应DMA请求","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237175413821441","title":"RISC (精简指令系统计算机）的技术思想是当代计算机设计的基础技术之一，(18) 不是RISC的特点。","analyze":"本题考查计算机系统结构的基础知识。<br>RISC结构的设计思想可归纳为：大多数指令是单周期完成的;采用Load/Store结构:硬连线控制；较少的指令数量和寻址方式；固定的指令格式；注重编译的优化等。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237176508534785"],"itemList":[{"id":"796237176454008833","questionId":"796237175413821441","content":" 指令长度固定，指令种类尽量少","answer":0,"chooseValue":"A"},{"id":"796237176483368961","questionId":"796237175413821441","content":" 增加寄存器数目，以减少访存次数","answer":0,"chooseValue":"B"},{"id":"796237176508534785","questionId":"796237175413821441","content":" 寻址方式丰富，指令功能尽可能强","answer":1,"chooseValue":"C"},{"id":"796237176533700609","questionId":"796237175413821441","content":" 用硬布线电路实现指令解码，以尽快对指令译码","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237279248011265","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>流水线技术是通过并行硬件来提高系统性能的常用方法。对于一个k段流水线，假设其各段的执行时间均相等（设为t），输入到流水线中的任务是连续的理想情况下，完成n个连续任务需要的总时间为（58）。若某流水线浮点加法运算器分为5段，所需要的时间分别是6ns、7ns、8ns、9ns和6ns，则其最大加速比为（59）。","analyze":"本题主要考查流水线技术的相关基础知识与计算。<br>流水线技术是通过并行硬件来提高系统性能的常用方法，它把一项任务分解为若干可以同时进行的并行工作。在任一时刻，任一任务只占其中一个操作部件，这样就可以实现多项任务的重叠执行。对于一个k段流水线，假设其各段的执行时间均相等（设为t)，输入到流水线中的任务是连续的理想情况下，从流水线的输出端看，用k个时钟周期输出第一项任务，其余n-1个时钟周期，每个周期输出一项任务，因此完成n个连续任务需要的总时间为(k+n-l)xt。加速比定义为顺序执行时间与流水线执行时间的比值，根据题干假设，顺序执行时间为6+7+8+9+6=36,在流水线中的执行时间为5+5-1=9，因此加速比为36/9=4。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237280233672705"],"itemList":[{"id":"796237280233672705","questionId":"796237279248011265","content":" 4","answer":1,"chooseValue":"A"},{"id":"796237280279810049","questionId":"796237279248011265","content":" 5","answer":0,"chooseValue":"B"},{"id":"796237280321753089","questionId":"796237279248011265","content":" 6","answer":0,"chooseValue":"C"},{"id":"796237280351113217","questionId":"796237279248011265","content":" 7","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237245005713409","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>总线规范会详细描述总线各方面的特性，其中（60）特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总周期中并行传输4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为（61）Mbps。","analyze":"本题主要考查考生对于计算机系统总线部分的性能分析与评估基础知识的理解与常握。总线规范会详细描述总线各方面的特性，其中物理特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总线周期中并行传输4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为 (4/2)x10=20 Mbps。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237245907488769"],"itemList":[{"id":"796237245907488769","questionId":"796237245005713409","content":" 20","answer":1,"chooseValue":"A"},{"id":"796237245932654593","questionId":"796237245005713409","content":" 40","answer":0,"chooseValue":"B"},{"id":"796237245962014721","questionId":"796237245005713409","content":" 60","answer":0,"chooseValue":"C"},{"id":"796237245987180545","questionId":"796237245005713409","content":" 80","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237219672117249","title":"在Cache-主存两级存储体系中，关于Cache的叙述，错误的是（15）。","analyze":"本题考查高速缓存的相关知识。<br>为解决高速CPU与低速内存之间的速度差异，最经济、有效的方法是在两者之间插入容量不大但操作速度很高的存储器高速缓存（Cache),起到缓冲作用，使CPU既可以以较快速度存取Cache中的数据，又不使系统成本过高。<br>与主存相比，Cache的容量很小，它保存的只是一部分主存内容的一个副本，且Cache与主存的数据交换是以块为单位。<br>地址映射即是应用某种方法把主存地址定位到Cache中，有全相联方式、直接方式和组相联方式三种方式。<br>(1)直接映射方式。<br>这是一种最简单而又直接的映射方法，指主存中每个块只能映射到Cache的一个特定的块。在该方法中，Cache块地址j和主存块地址i的关系为：<br>j=i mod C<sub>b<br></sub>其中C<sub>b</sub>是Cache的块数。这样，整个Cache地址与主存地址的低位部分完全相同。直接映射法的优点是所需硬件简单，只需要容量较小的按地址访问的区号标志表存储器和少量比较电路；缺点是Cache块冲突概率较高，只要有两个或两个以上经常使用的块恰好被映射到Cache中的同一个块位置时，就会使Cache命中率急剧下降。<br>(2)全相联映射方式。<br>这种映射方式允许主存的每一块信息可以存到Cache的任何一个块空间，也允许从已被占满的Cache中替换掉任何一块信息。全相联映射的优点是块冲突概率低：其缺点是访问速度慢，并且成本太高。<br>(3)组相联映射方式。<br>这种方式是前两种方式的折衷方案。这种映射方式在组间是直接映射，而组内是全相联映射，其性能和复杂性介于直接映射和全相联映射之间。<br>CPU在访问内存时，首先判断所要访问的内容是否在Cache中，如果在，就称为“命中”，此时CPU直接从Cache中调用该内容；否则，就称为“不命中”。一般来说，Cache的存储容量比主存的容量小得多，但不能太小，太小会使命中率太低；也没有必要过大，过大不仅会增加成本，而且当容量超过一定值后，命中率随容量的增加将不会有明显地增长。","multi":0,"questionType":1,"answer":"D","chooseItem":["796237220657778689"],"itemList":[{"id":"796237220594864129","questionId":"796237219672117249","content":" Cache设计的主要目标是在成本允许的情况下达到较高的命中率，使存储系统具有最短的平均访问时间","answer":0,"chooseValue":"A"},{"id":"796237220611641345","questionId":"796237219672117249","content":" Cache设计的一个重要原则是在争取获得较快的存取速度和花费较低的存储成本之间达到合理的折衷","answer":0,"chooseValue":"B"},{"id":"796237220636807169","questionId":"796237219672117249","content":" 除了Cache容量和块的大小，地址相联方式和替换策略也会影响Cache的命中率","answer":0,"chooseValue":"C"},{"id":"796237220657778689","questionId":"796237219672117249","content":" 在速度要求较高的场合采用直接映像，在速度要求较低的场合采用组相联或全相联","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237275775127553","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>流水线技术是通过并行硬件来提高系统性能的常用方法。对于一个k段流水线，假设其各段的执行时间均相等（设为t），输入到流水线中的任务是连续的理想情况下，完成n个连续任务需要的总时间为（58）。若某流水线浮点加法运算器分为5段，所需要的时间分别是6ns、7ns、8ns、9ns和6ns，则其最大加速比为（59）。","analyze":"本题主要考查流水线技术的相关基础知识与计算。<br>流水线技术是通过并行硬件来提高系统性能的常用方法，它把一项任务分解为若干可以同时进行的并行工作。在任一时刻，任一任务只占其中一个操作部件，这样就可以实现多项任务的重叠执行。对于一个k段流水线，假设其各段的执行时间均相等（设为t)，输入到流水线中的任务是连续的理想情况下，从流水线的输出端看，用k个时钟周期输出第一项任务，其余n-1个时钟周期，每个周期输出一项任务，因此完成n个连续任务需要的总时间为(k+n-l)xt。加速比定义为顺序执行时间与流水线执行时间的比值，根据题干假设，顺序执行时间为6+7+8+9+6=36,在流水线中的执行时间为5+5-1=9，因此加速比为36/9=4。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237277104721921"],"itemList":[{"id":"796237277075361793","questionId":"796237275775127553","content":" nkt","answer":0,"chooseValue":"A"},{"id":"796237277104721921","questionId":"796237275775127553","content":" (k+n-1)t","answer":1,"chooseValue":"B"},{"id":"796237277142470657","questionId":"796237275775127553","content":" (n-k)kt","answer":0,"chooseValue":"C"},{"id":"796237277171830785","questionId":"796237275775127553","content":" (k+n+1)t","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237284616720385","title":"浮点数在机器中的表示形式如下所示，若阶码的长度为e，尾数的长度为m，则以下关于浮点表示的叙述中，正确的是（18）。<br><img alt=\"\" width=\"594\" height=\"40\" src=\"https://image.chaiding.com/ruankao/1b9b420bd8c75a33886c561bea46d2d9.jpg?x-oss-process=style/ruankaodaren\"><br>①e的值影响浮点数的范围，e越大，所表示的浮点数值范围越大<br>②e的值影响浮点数的精度，e越大，所表示的浮点数精度越高<br>③m的值影响浮点数的范围，m越大，所表示的浮点数范围越大<br>④m的值影响浮点数的精度，m越大，所表示的浮点数精度越高","analyze":"本题考查计算机系统基础知识。<br>在浮点表示方式下，浮点数的精度由尾数部分来确定，范围则取决于阶码的长度，因此阶码e越大，所表示的浮点数值范围越大，尾数的位数m越大，所表示的浮点数精度越高。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237285682073601"],"itemList":[{"id":"796237285606576129","questionId":"796237284616720385","content":" ①③","answer":0,"chooseValue":"A"},{"id":"796237285640130561","questionId":"796237284616720385","content":" ②③","answer":0,"chooseValue":"B"},{"id":"796237285682073601","questionId":"796237284616720385","content":" ①④","answer":1,"chooseValue":"C"},{"id":"796237285719822337","questionId":"796237284616720385","content":" ②④","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237242052923393","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>总线规范会详细描述总线各方面的特性，其中（60）特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总周期中并行传输4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为（61）Mbps。","analyze":"本题主要考查考生对于计算机系统总线部分的性能分析与评估基础知识的理解与常握。总线规范会详细描述总线各方面的特性，其中物理特性规定了总线的线数，以及总线的插头、插座的形状、尺寸和信号线的排列方式等要素。总线带宽定义为总线的最大数据传输速率，即每秒传输的字节数。假设某系统总线在一个总线周期中并行传输4B信息，一个总线周期占用2个时钟周期，总线时钟频率为10MHz，则总线带宽为 (4/2)x10=20 Mbps。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237242971475969"],"itemList":[{"id":"796237242971475969","questionId":"796237242052923393","content":" 物理","answer":1,"chooseValue":"A"},{"id":"796237242996641793","questionId":"796237242052923393","content":" 电气","answer":0,"chooseValue":"B"},{"id":"796237243026001921","questionId":"796237242052923393","content":" 功能","answer":0,"chooseValue":"C"},{"id":"796237243046973441","questionId":"796237242052923393","content":" 时间","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237233697869825","title":"在计算机系统中，对构成内存的半导体存储器进行自检的方法有许多种，其中对(14)一般采用对其内容求累加和进行自检的方法。","analyze":"一般来讲，RAM类存储器通过写入OxAA，0x55等数字再读出的方式进行自检；ROM类存储器通过累加和校验进行自检。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237234796777473"],"itemList":[{"id":"796237234796777473","questionId":"796237233697869825","content":" ROM","answer":1,"chooseValue":"A"},{"id":"796237234821943297","questionId":"796237233697869825","content":" DRAM","answer":0,"chooseValue":"B"},{"id":"796237234847109121","questionId":"796237233697869825","content":" SDRAM","answer":0,"chooseValue":"C"},{"id":"796237234868080641","questionId":"796237233697869825","content":" DDR SDRAM","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237263796195329","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>某计算机系统的结构如下图所示，按照弗林（Michael J.Flynn）提出的分类法，它属于（17），其中，PU<sub>i</sub>(i=1,…,n)为处理单元，CU为控制部件，MM<sub>j</sub>(j=1,…,n)为存储部件。该计算机（18）。<br><img alt=\"\" width=\"274\" height=\"176\" src=\"https://image.chaiding.com/ruankao/33fcf4f9873d57cac7761a283b5caef4.jpg?x-oss-process=style/ruankaodaren\">","analyze":"显然，该计算机将大量重复设置的处理单元按一定方式互连成阵列，在单一控制部件CU(Control Unit)控制下对各自所分配的不同数据并行执行同一指令规定的操作，是操作并行的SIMD计算机。因此，采用了资源重复的措施开发并行性。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237264748302337"],"itemList":[{"id":"796237264727330817","questionId":"796237263796195329","content":" 通过时间重叠实现并行性","answer":0,"chooseValue":"A"},{"id":"796237264748302337","questionId":"796237263796195329","content":" 通过资源重复实现并行性","answer":1,"chooseValue":"B"},{"id":"796237264773468161","questionId":"796237263796195329","content":" 通过资源共享实现并行性","answer":0,"chooseValue":"C"},{"id":"796237264798633985","questionId":"796237263796195329","content":" 通过精简指令系统实现并行性","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237255625691137","title":"某4级流水线如下图所示，若每3△t向该流水线输入一个任务，连续输入4个，则该流水线的加速比为(18)。<br><img alt=\"\" width=\"362\" height=\"59\" src=\"https://image.chaiding.com/ruankao/379182b825dc4a297cb9970e62d03c35.jpg?x-oss-process=style/ruankaodaren\">","analyze":"本题考査流水线知识。<br>流水线的加速比定义如下：为完成一批任务，不使用流水线所用的时间与使用流水线所用的时间之比称为流水线的加速比。<br>因此，该流水线的加速比为28△t:16△t，即7:4=1.75。","multi":0,"questionType":1,"answer":"B","chooseItem":["796237256586186753"],"itemList":[{"id":"796237256552632321","questionId":"796237255625691137","content":" 4","answer":0,"chooseValue":"A"},{"id":"796237256586186753","questionId":"796237255625691137","content":" 1.75","answer":1,"chooseValue":"B"},{"id":"796237256619741185","questionId":"796237255625691137","content":" 1.5","answer":0,"chooseValue":"C"},{"id":"796237256649101313","questionId":"796237255625691137","content":" 1","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237182862905345","title":"下列关于虚拟存储器的叙述中，正确的是（）。","analyze":"本题考查计算机系统基础知识。<br>所有的存储器设备按照一定的层次逻辑关系通过软硬件连接起来，并进行有效的管理，就形成了存储体系。一般计算机系统中主要有两种存储体系：Cache存储体系(由Cache和主存储器构成，主要目的是提高存储器访问速度(和虚拟存储体系(由主存储器和在线磁盘存储器构成，主要目的是扩大存储器容量(。其中Cache存储体系对系统程序员以上均透明，而虚拟存储体系对应用程序员透明，对系统程序员不透明。","multi":0,"questionType":1,"answer":"A","chooseItem":["796237183781457921"],"itemList":[{"id":"796237183781457921","questionId":"796237182862905345","content":" 对应用程序员透明，对系统程序员不透明","answer":1,"chooseValue":"A"},{"id":"796237183806623745","questionId":"796237182862905345","content":" 对应用程序员不透明，对系统程序员透明","answer":0,"chooseValue":"B"},{"id":"796237183831789569","questionId":"796237182862905345","content":" 对应用程序员、系统程序员都不透明","answer":0,"chooseValue":"C"},{"id":"796237183856955393","questionId":"796237182862905345","content":" 对应用程序员、系统程序员都透明","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237158758240257","title":"(15)不是复杂指令系统计算机CISC的特征。","analyze":"RISC技术通过简化计算机指令功能，使指令的平均执行周期减少，从而提高计算机的工作主频，同时大量使用通用寄存器来提高子程序执行的速度。相反，设置多种指令格式、采用丰富的寻址方式和长度可变的指令等则是复杂指令系统计算机CISC的特点。","multi":0,"questionType":1,"answer":"D","chooseItem":["796237159882313729"],"itemList":[{"id":"796237159823593473","questionId":"796237158758240257","content":" 丰富的寻址方式","answer":0,"chooseValue":"A"},{"id":"796237159844564993","questionId":"796237158758240257","content":" 多种指令格式","answer":0,"chooseValue":"B"},{"id":"796237159865536513","questionId":"796237158758240257","content":" 指令长度可变","answer":0,"chooseValue":"C"},{"id":"796237159882313729","questionId":"796237158758240257","content":" 设置大量通用寄存器","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237193285750785","title":"以下关于复杂指令集计算机（Complex Instruction Set Computer, CISC)弊端的叙述中，错误的是（15）。","analyze":"本题考查指令系统知识。<br>RISC和CISC是目前设计制造微处理器的两种典型技术，虽然它们都试图在体系结构、操作运行、软件硬件、编译时间和运行时间等诸多因素中做出某种平衡，以求达到高效的目的，但采用的方法不同，主要区别有：<br>①指令系统：RISC设计者把主要精力放在那些经常使用的指令上，尽量使它们具有简单高效的特色。对不常用的功能，常通过组合指令来完成。因此，在RISC机器上实现特殊功能时，效率可能较低。但可以利用流水技术和超标量技术加以改进和弥补。<br>而CISC计算机的指令系统比较丰富，有专用指令来完成特定的功能。因此，处理特殊任务效率较高。<br>②存储器操作：RISC对存储器操作有限制，使控制简单化；而CISC机器的存储器操作指令多，操作直接。<br>③程序：RISC汇编语言程序一般需要较大的内存空间，实现特殊功能时程序复杂， 不易设计；而CISC汇编语言程序编程相对简单，科学计算及复杂操作的程序设计相对容易，效率较高。<br>④中断：RISC机器在一条指令执行的适当地方可以响应中断；而CISC机器是在一条指令执行结束后响应中断。<br>⑤CPU: RISC的CPU包含有较少的单元电路，因而面积小、功耗低；而CISC CPU包含有丰富的电路单元，因而功能强、面积大、功耗大。<br>⑥设计周期：RISC微处理器结构简单，布局紧凑，设计周期短，且易于采用最新技术；CISC微处理器结构复杂，设计周期长<br>⑦用户使用：RISC微处理器结构简单，指令规整，性能容易把握，易学易用；CISC微处理器结构复杂，功能强大，实现特殊功能容易。<br>⑧应用范围：由于RISC指令系统的确定与特定的应用领域有关，故RISC机器更<br>适合于专用机；而CISC机器则更适合于通用机。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237194388852737"],"itemList":[{"id":"796237194342715393","questionId":"796237193285750785","content":" 指令集过分庞杂","answer":0,"chooseValue":"A"},{"id":"796237194367881217","questionId":"796237193285750785","content":" 每条复杂指令需要占用过多的CPU周期","answer":0,"chooseValue":"B"},{"id":"796237194388852737","questionId":"796237193285750785","content":" CPU中的寄存器过多，利用率低","answer":1,"chooseValue":"C"},{"id":"796237194409824257","questionId":"796237193285750785","content":" 强调数据控制，导致设计复杂，研制周期长","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237210566283265","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>假设某磁盘的每个磁道划分成11个物理块，每块存放1个逻辑记录。逻辑记录R0, R1，…，R9, R10存放在同一个磁道上，记录的存放顺序如下表所示：<br><img alt=\"\" width=\"537\" height=\"45\" src=\"https://image.chaiding.com/ruankao/73b71b0827fb9eed68909c82c6c96412.jpg?x-oss-process=style/ruankaodaren\"><br>如果磁盘的旋转周期为33ms，磁头当前处在R0的开始处。若系统使用单缓冲区顺序处理这些记录，每个记录处理时间为3ms，则处理这11个记录的最长时间为（48）：若对信息存储进行优化分布后，处理11个记录的最少时间为（49）。","analyze":"本题考查操作系统磁盘优化方面的基础知识。<br>试题（48）分析：系统读记录的时间为33/ll=3ms，对第一种情况：系统读出并处理记录R0之后，将转到记录R2的开始处，所以为了读出记录R1，磁盘必须再转一圈，需要33ms (转一圈）的时间。这样，处理11个记录的总时间应为366ms，因为处理前10个记录（即R0, Rl，R2,…，R9)的时间为10x(33+3) ms=360ms,读记录R10及处理记录R10时间为6ms，所以处理11个记录的总时间为360ms+6ms=366ms。","multi":0,"questionType":1,"answer":"C","chooseItem":["796237211623247873"],"itemList":[{"id":"796237211526778881","questionId":"796237210566283265","content":" 3ms","answer":0,"chooseValue":"A"},{"id":"796237211581304833","questionId":"796237210566283265","content":" 336ms","answer":0,"chooseValue":"B"},{"id":"796237211623247873","questionId":"796237210566283265","content":" 366ms","answer":1,"chooseValue":"C"},{"id":"796237211644219393","questionId":"796237210566283265","content":" 376ms","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237225481228289","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>在磁盘调度管理中，应先进行移臂调度，再进行旋转调度。若磁盘移动臂位于22号柱面上，进程的请求序列如下表所示。若采用最短移臂调度算法，则系统的响应序列应为（47）,其平均移臂距离为（48）。<br><img alt=\"\" width=\"412\" height=\"220\" src=\"https://image.chaiding.com/ruankao/5d1e6b7b941507af14a8a36a19bdc192.jpg?x-oss-process=style/ruankaodaren\">","analyze":"当进程请求读磁盘时，操作系统先进行移臂调度，再进行旋转调度。由于移动臂位于22号柱面上，按照最短寻道时间优先的响应柱面序列为25—18—40—45。按照旋转调度的原则分析如下：<br>进程在25号柱面上的响应序列为②一⑧一③，因为进程访问的是不同磁道上的不同编号的扇区，旋转调度总是让首先到达读写磁头位置下的扇区先进行传送操作。<br>进程在18号柱面上的响应序列为⑤一⑦一①，或⑤一①一⑦。对于①和⑦可以任选一个进行读写，因为进程访问的是不同磁道上具有相同编号的扇区，旋转调度可以任选一个读写磁头位置下的扇区进行传送操作。<br>进程在40号柱面上的响应序列为④一⑥；由于⑨在45号柱面上，故响应最后响应。从上面的分析中可以得出按照最短寻道时间优先的响应序列为②⑧③⑤⑦①","multi":0,"questionType":1,"answer":"B","chooseItem":["796237226412363777"],"itemList":[{"id":"796237226383003649","questionId":"796237225481228289","content":" ②⑧③④⑤①⑦⑥⑨","answer":0,"chooseValue":"A"},{"id":"796237226412363777","questionId":"796237225481228289","content":" ②⑧③⑤⑦①④⑥⑨","answer":1,"chooseValue":"B"},{"id":"796237226445918209","questionId":"796237225481228289","content":" ①②③④⑤⑥⑦⑧⑨","answer":0,"chooseValue":"C"},{"id":"796237226471084033","questionId":"796237225481228289","content":" ②③⑧④⑥⑨①⑤⑦","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237299015766017","title":"计算机系统中主机与外设间的输入输出控制方式有多种，其中占用主机CPU时间最多的是（17）方式。","analyze":"本题考查计算机系统的基础知识。<br>程序查询方式是主机通过程序直接控制输入输出设备的工作，此方式下进行主机和外设间的数据交换时，主机CPU要不断查询外设状态、控制数据传送过程而不进行其他操作。<br>在中断方式下，主机向输入输出设备发出数据传送的命令后，仍可以进行其他操作， 外设在完成发送或接收数据的准备工作后，向主机发出中断请求，进行数据传送。在此方式下，外设的准备工作可独立进行，主机在此期间进行其他操作，但输入输出的数据传送操作仍在主机CPU控制下进行。<br>在DMA方式下，输入输出设备与内存储器直接相连，数据传送由DMA控制器而不是主机CPU控制。CPU除了传送开始和终了时进行必要的处理外，不参与数据传送的过程。<br>输入输出通道实际上是一种专用处理机。进行输入输出操作时，通道取出并执行保存在主机主存储器中的程序，控制输入输出设备与主存储器之间的数据交换。这种方式下CPU只需进行少量的处理就实现了并行操作。","multi":0,"questionType":1,"answer":"D","chooseItem":["796237300152422401"],"itemList":[{"id":"796237300089507841","questionId":"796237299015766017","content":" 通道方式","answer":0,"chooseValue":"A"},{"id":"796237300110479361","questionId":"796237299015766017","content":" DMA","answer":0,"chooseValue":"B"},{"id":"796237300131450881","questionId":"796237299015766017","content":" 中断","answer":0,"chooseValue":"C"},{"id":"796237300152422401","questionId":"796237299015766017","content":" 程序查询","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796237213602959361","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>假设某磁盘的每个磁道划分成11个物理块，每块存放1个逻辑记录。逻辑记录R0, R1，…，R9, R10存放在同一个磁道上，记录的存放顺序如下表所示：<br><img alt=\"\" width=\"537\" height=\"45\" src=\"https://image.chaiding.com/ruankao/c1c2109dd4edab7d6f3ec3fcd75c07d0.jpg?x-oss-process=style/ruankaodaren\"><br>如果磁盘的旋转周期为33ms，磁头当前处在R0的开始处。若系统使用单缓冲区顺序处理这些记录，每个记录处理时间为3ms，则处理这11个记录的最长时间为（48）：若对信息存储进行优化分布后，处理11个记录的最少时间为（49）。","analyze":"试题（49）分析：对于第二种情况，若对信息进行分布优化，结果如下:<br><img alt=\"\" width=\"534\" height=\"43\" src=\"https://image.chaiding.com/ruankao/d86377bb04f8c268b947f33ec30dd618.jpg?x-oss-process=style/ruankaodaren\"><br>从中可以看出，当读出记录R0并处理结束后，磁头刚好转至R1记录的开始处，立即就可以读出R1并处理，因此处理11个记录的总时间为：<br>11*(3ms(读记录)+3ms(处理记录))=11*6ms=66ms ","multi":0,"questionType":1,"answer":"B","chooseItem":["796237214529900545"],"itemList":[{"id":"796237214508929025","questionId":"796237213602959361","content":" 33ms","answer":0,"chooseValue":"A"},{"id":"796237214529900545","questionId":"796237213602959361","content":" 66ms","answer":1,"chooseValue":"B"},{"id":"796237214550872065","questionId":"796237213602959361","content":" 86ms","answer":0,"chooseValue":"C"},{"id":"796237214571843585","questionId":"796237213602959361","content":" 93ms","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234561716506625","title":"雷达设计人员在设计数字信号处理单元时，其处理器普遍采用DSP芯片(比如：TI公司的TMS320C63xx)，通常DSP芯片采用哈佛(HarVard)体系结构，以下关于哈佛结构特征的描述，不正确的是（ ）。","analyze":"哈佛结构是一种将程序指令存储和数据存储分开的存储器结构。哈佛结构是一种并行体系结构，它的主要特点是将程序和数据存储在不同的存储空间中，即程序存储器和数据存储器是两个独立的存储器，每个存储器独立编址、独立访问。 与两个存储器相对应的是系统的4条总线：程序和数据的数据总线与地址总线。这种分离的程序总线和数据总线可允许在一个机器周期内同时获得指令字（来自程序存储器）和操作数（来自数据存储器），从而提高了执行速度，提高了数据的吞吐率。又由于程序和数据存储在两个分开的物理空间中，因此取址和执行能完全重叠。中央处理器首先到程序指令存储器中读取程序指令内容，解码后得到数据地址，再到相应的数据存储器中读取数据，并进行下一步的操作（通常是执行）。程序指令存储和数据存储分开，可以使指令和数据有不同的数据宽度。 哈佛结构能在一个机器周期内同时获取指令字与操作数，但做不到一个机器周期内多次访问存储器\n","multi":0,"questionType":1,"answer":"B","chooseItem":["796234562752499713"],"itemList":[{"id":"796234562723139585","questionId":"796234561716506625","content":" 程序和数据具有独立的存储空间，允许同时取指令和取操作数，并允许在程序空间或数据空间之间互传数据","answer":0,"chooseValue":"A"},{"id":"796234562752499713","questionId":"796234561716506625","content":" 处理器内部采用多总线结构，保证了在一个机器周期内可以多次访问程序空间和数据空间","answer":1,"chooseValue":"B"},{"id":"796234562781859841","questionId":"796234561716506625","content":" 哈佛体系结构强调的是多功能，适合多种不同的环境和任务，强调兼容性","answer":0,"chooseValue":"C"},{"id":"796234562802831361","questionId":"796234561716506625","content":" 处理器内部采用多处理单元，可以在一个指令周期内同时进行运算","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234318195216385","title":"RISC-V是基于精简指令集计算原理建立的开放指令集架构，以下关于RISC-V的说法中，不正确的是( )。","analyze":"本题考查处理器体系结构的基础知识。<br> RISC(Reduced Instruction Set Computer)是精简指令集计算机的简称。RISC起源于20世纪80年代的MIPS处理器。RISC-V是一种基于精简指令集（RISC)原则的开源指令架构 (ISA)，RISC-V指令集可以自由地用于任何目的，允许任何人设计、制造和销售RISC-V芯片和软件。其主要特征是完全开源、架构简单、易于移植、模块化设计和具备完善的工具链等。而ARM处理器的架构是基于RISC架构设计的，因此RISC-V与ARM的架构属于同一种。RISC-V架构不仅短小精悍，而且其不同的部分还能以模块化的方式组织在一起，从而试图通过一套统一的架构满足各种不同的应用场景、RISC-V基础指令集中只有40多条指令，加上其他模块化扩展指令总共也就几十条指令、RISC-V1SA可以免费使用，允许任何人设计、制造和销售RISC-V芯片和软件都是RISC-V的基本特征，RISC-V也是X86架构的一种，它和ARM架构之间存在很大区别是错误的说法，其正确描述应该是RISC-V是ARM架构的一种，二者整体架构类似，但与X86架构存在很大区别。","multi":0,"questionType":1,"answer":"D","chooseItem":["796234319134740481"],"itemList":[{"id":"796234319101186049","questionId":"796234318195216385","content":" RISC-V架构不仅短小精悍，而且其不同的部分还能以模块化的方式组织在一起，从而试图通过一套统一的架构满足各种不同的应用场景","answer":0,"chooseValue":"A"},{"id":"796234319113768961","questionId":"796234318195216385","content":" RISC-V基础指令集中只有40多条指令，加上其他模块化扩展指令总共也就几十条指令","answer":0,"chooseValue":"B"},{"id":"796234319122157569","questionId":"796234318195216385","content":" RISC-V1SA可以免费使用，允许任何人设计、制造和销售RISC-V芯片和软件","answer":0,"chooseValue":"C"},{"id":"796234319134740481","questionId":"796234318195216385","content":" RISC-V也是X86架构的一种，它和ARM架构之间存在很大区别","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234801416785921","title":"以下关于CPU和GPU的叙述中，错误的是（ ）。","analyze":"本题考查计算机系统知识。<br>CPU是指计算机系统中的中央处理器，GPU是指图形处理单元，它们的设计目标不同，因此针对不同的应用场景。CPU需要很强的通用性来处理各种不同的数据类型，同时需要进行逻辑判断，会引入大量的分支跳转和中断的处理，这些都使得CPU的内部结构异常复杂。相对而言，计算能力只是CPU很小的一部分。GPU采用了数量众多的计算单元和超长的流水线，但只有非常简单的控制逻辑并省去了高速缓存（Cache)，采用的是单指令流多数据流（SIMD)架构，用于处理类型高度统一且相互无依赖的大规模数据和不需要被打断的纯净的计算环境。","multi":0,"questionType":1,"answer":"C","chooseItem":["796234802595385345"],"itemList":[{"id":"796234802549248001","questionId":"796234801416785921","content":" CPU适合于需要处理各种不同的数据类型、大量的分支跳转及中断等场合","answer":0,"chooseValue":"A"},{"id":"796234802574413825","questionId":"796234801416785921","content":" CPU利用较高的主频、高速缓存（Cache）和分支预测等技术来执行指令","answer":0,"chooseValue":"B"},{"id":"796234802595385345","questionId":"796234801416785921","content":" GPU采用MISD（Multiple Instruction Single Data）并行计算架构","answer":1,"chooseValue":"C"},{"id":"796234802624745473","questionId":"796234801416785921","content":" GPU的特点是比CPU包含更多的计算单元和更简单的控制单元","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235043059027969","title":"执行CPU指令时，在一个指令周期的过程中，首先需从内存读取要执行的指令，此时先要将指令的地址即（ ）的内容送到地址总线上。","analyze":"本题考查计算机系统基础知识。<br>CPU中通常设置多个寄存器，其中一些寄存器有固定的用途。指令被执行时，首先需要将指令从内存读取出来，指令的地址则放在程序计数器（PC)中，取得的指令则暂存在指令寄存器中。状态寄存器保存指令执行过程中的状态及控制信息（例如，溢出、结果为负或者为0等)，通用寄存器则常用来暂存数据或作其他用途。","multi":0,"questionType":1,"answer":"C","chooseItem":["796235044053078017"],"itemList":[{"id":"796235043985969153","questionId":"796235043059027969","content":" 指令寄存器(IR)","answer":0,"chooseValue":"A"},{"id":"796235044023717889","questionId":"796235043059027969","content":" 通用寄存器(GR)","answer":0,"chooseValue":"B"},{"id":"796235044053078017","questionId":"796235043059027969","content":" 程序计数器(PC)","answer":1,"chooseValue":"C"},{"id":"796235044090826753","questionId":"796235043059027969","content":" 状态寄存器 (PSW)","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234804793200641","title":"计算机系统是一个硬件和软件综合体，位于硬联逻辑层上面的微程序是用微指令编写的。以下叙述中，正确的是（ ）。","analyze":"本题考查计算机系统硬件知识。<br>微程序是指实现指令系统中指令功能的程序，显然是由硬件直接解释执行的。","multi":0,"questionType":1,"answer":"A","chooseItem":["796234806013743105"],"itemList":[{"id":"796234806013743105","questionId":"796234804793200641","content":" 微程序一般由硬件执行","answer":1,"chooseValue":"A"},{"id":"796234806030520321","questionId":"796234804793200641","content":" 微程序一般是由操作系统来调度和执行","answer":0,"chooseValue":"B"},{"id":"796234806055686145","questionId":"796234804793200641","content":" 微程序一般用高级语言构造的编译器翻译后来执行","answer":0,"chooseValue":"C"},{"id":"796234806072463361","questionId":"796234804793200641","content":" 微程序一般用高级语言构造的解释器件来解释执行","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235278816661505","title":"某浮点数格式如下：7位阶码（包含一个符号位），9位尾数（包含一个符号位）。若阶码用移码、尾数用规格化的补码表示，则浮点数所能表示数的范围是（15）。","analyze":"本题考查计算机系统数据表示基础知识。<br>用浮点格式表示数N时，形式为：N=2<sup>E</sup>×F，其中E称为阶码，F为尾数。<br>如果浮点数的阶码（包括1位阶符）用R位的移码表示，尾数（包括1位数符）用M位的补码表示，则这种浮点数所能表示的数值范围如下。<br><img alt=\"\" width=\"399\" height=\"24\" src=\"https://image.chaiding.com/ruankao/9643d601296cccecb3cdc148289d8a1f.jpg?x-oss-process=style/ruankaodaren\">","multi":0,"questionType":1,"answer":"A","chooseItem":["796235279781351425"],"itemList":[{"id":"796235279781351425","questionId":"796235278816661505","content":" -2<sup>63</sup>～(1-2<sup>-8</sup>)×2<sup>63</sup>","answer":1,"chooseValue":"A"},{"id":"796235279810711553","questionId":"796235278816661505","content":" -2<sup>64</sup>～(1-2<sup>-7</sup>)×2<sup>64</sup>","answer":0,"chooseValue":"B"},{"id":"796235279844265985","questionId":"796235278816661505","content":" -(1-2<sup>-8</sup>)×2<sup>63</sup>～2<sup>63</sup>","answer":0,"chooseValue":"C"},{"id":"796235279873626113","questionId":"796235278816661505","content":" -(1-2<sup>-7</sup>)×2<sup>64</sup>～(1-2<sup>-8</sup>)×2<sup>63</sup>","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234564933537793","title":"某16位AD芯片中标注电压范围是-5V～＋5V,请问该款AD芯片的分辨率是（ ）。","analyze":"AD芯片是模拟与数字信号的转换芯片，其主要功能是将外部模拟信号通过AD芯片转换成计算机可以处理的数字信号。AD芯片的分辨率是指AD转换器对输入信号的分辨能力。通常，AD转换的分辨率=参考电压/(总元素-1)，而总元素是指AD位数所能表示的最大数值，如：8位AD，其总元素是256。所以，16位AD的分辨率=(10V)/(65536-1)=0.01526mV。","multi":0,"questionType":1,"answer":"C","chooseItem":["796234565998891009"],"itemList":[{"id":"796234565948559361","questionId":"796234564933537793","content":" 10V","answer":0,"chooseValue":"A"},{"id":"796234565973725185","questionId":"796234564933537793","content":" 0.0763mV","answer":0,"chooseValue":"B"},{"id":"796234565998891009","questionId":"796234564933537793","content":" 0.1526mV","answer":1,"chooseValue":"C"},{"id":"796234566024056833","questionId":"796234564933537793","content":" 0.3052mV","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234321177366529","title":"IEEE-1394总线采用菊花链的拓扑结构时，可最多支持63个节点。当1394总线支持1023条桥接总线时，最多可以采用菊花链的拓扑结构互连( )个节点。","analyze":"本题考査计算机总线设计的基础知识。<br> IEEE-1394串行总线是当前计算机系统设计中普遍采用的高速数据传输总线，相比USB总线，它具有速度快、距离远和传输稳定等特征。IEEE-1394通常可以树形或菊花链形拓扑结构连接63台设备。每个1394设备是一个节点，设备地址有64bit。其中段ID占lObit，节点ID占6bit，其余的48bit是存储器地址。如果在一个复杂的系统中使用菊花链形拓扑结构，那么，lObit的总线ID就可表示1023个总线段，因此，1394总线支持1023条桥接总线时，最多可以互连1023X63=64449个节点。","multi":0,"questionType":1,"answer":"C","chooseItem":["796234322322411521"],"itemList":[{"id":"796234322263691265","questionId":"796234321177366529","content":" 1023","answer":0,"chooseValue":"A"},{"id":"796234322288857089","questionId":"796234321177366529","content":" 1086","answer":0,"chooseValue":"B"},{"id":"796234322322411521","questionId":"796234321177366529","content":" 64449","answer":1,"chooseValue":"C"},{"id":"796234322343383041","questionId":"796234321177366529","content":" 645535","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234567957630977","title":"以下关于多核处理器的说法中，不正确的是（ ）。","analyze":"SMP是一种对称型多核处理系统结构，MP是一种非对称型多处理器系统结构，而BMP是一种介于对称、非对称之间的多核处理系统结构。多核处理器可降低计算机体积与功耗，多核处理器与多处理器的不同之处就在于将两个以上的独立CPU集成到一个硅片（电路）中，在多核处理系统中，进程可以同时运行在不同处理器核上，真正实现操作系统线程的并行执行。<br> 由于SMP、BMP和MP的结构与硬件结构有着紧密关系，硬件的结构决定着采用哪种多核使用方式。以上所述，SMP、BMP和MP是多核处理器系统通常采用的三种结构，采用哪种结构与应用场景相关，而无须考虑硬件的组成差异的说法是不正确的。","multi":0,"questionType":1,"answer":"B","chooseItem":["796234568981041153"],"itemList":[{"id":"796234568960069633","questionId":"796234567957630977","content":" 采用多核处理器可以降低计算机系统的功耗和体积","answer":0,"chooseValue":"A"},{"id":"796234568981041153","questionId":"796234567957630977","content":" SMP、BMP和MP是多核处理器系统通常采用的三种结构，采用哪种结构与应用场景相关，而无须考虑硬件的组成差异","answer":1,"chooseValue":"B"},{"id":"796234569006206977","questionId":"796234567957630977","content":" 在多核处理器中，计算机可以同时执行多个进程，而操作系统中的多个线程也可以并行执行","answer":0,"chooseValue":"C"},{"id":"796234569027178497","questionId":"796234567957630977","content":" 多核处理器是将两个或更多的独立处理器封装在一起，集成在一个电路中","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234324272762881","title":"在计算机体系结构设计时，通常在CPU和内存之间设置小容量的Cache机制，以提高CPU数据输入输出速率。通常当Cache已存满数据后，新数据必须替换（淘汰）Cache中的 某些旧数据。常用的数据替换算法包括（16）。","analyze":"本题考査计算机体系结构设计的基础知识。<br> 计算机设计中，Cache机制是提高计算机运行速度的基本机制之一，它是CPU与内存之间能够快速交换数据的一种设计方法，Cache的命中率高低是衡量设计优劣的一种标准。在Cache新旧数据替换过程中，好的Cache替换算法可以产生较高的命中率。目前比较流行的算法包括：<br> ①随机算法（RAND):若当前Cache被填满，则随机选择一块进行替换。<br> ②先进先出算法（FIFO):遵循先入先出原则，若当前Cache被填满，则替换最早进入Cache的块。<br> ③先进后出算法（FILO):遵循先入后出原则，若当前Cache被填满，则替换最晚进入Cache的块。<br> ④近期最少使用算法（LRU):若当前Cache被填满，则将最近最少使用的内容替换出Cache。<br> ⑤最近最常使用算法（MRU):与LRU类似，差别在于它是按使用的频率来排序，最少使用的数据最先被替换。<br> 先进后出算法（FILO)不适合Cache替换，它会降低Cache的命中率；轮询调度（RRS)不是Cache替换算法，主要以轮叫的方式依次请求调度不同的服务器适用于服务器调度；近期最少使用（LRU) 和最近最常使用（MRU)是两种互斥的算法，最常用的还是LRU。","multi":0,"questionType":1,"answer":"A","chooseItem":["796234325166149633"],"itemList":[{"id":"796234325166149633","questionId":"796234324272762881","content":" 随机算法、先进先出（FIFO)和近期最少使用（LRU)","answer":1,"chooseValue":"A"},{"id":"796234325199704065","questionId":"796234324272762881","content":" 随机算法、先进后出（FILO)和近期最少使用（LRU)","answer":0,"chooseValue":"B"},{"id":"796234325229064193","questionId":"796234324272762881","content":" 轮询调度(RRS)、先进先出(FIFO)和近期最少使用（LRU)","answer":0,"chooseValue":"C"},{"id":"796234325245841409","questionId":"796234324272762881","content":" 先进先出（FIFO)、近期最少使用（LRU)和最近最常使用（MRU)","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234808094117889","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>计算机系统中，（16）方式是根据所访问的内容来决定要访问的存储单元，常用在（17）存储器中。","analyze":"本题考查计算机系统知识。<br>相联存储器是一种按内容访问的存储器。其工作原理就是把数据或数据的某一部分作为关键字，按顺序写入信息，读出时并行地将该关键字与存储器中的每一单元进行比较，找出存储器中所有与关键字相同的数据字，特别适合于信息的检索和更新，因此，相联存取方式是根据所访问的内容来决定要访问的存储单元。<br>相联存储器可用在高速缓冲存储器（Cache)中，在虚拟存储器中用来作为段表、页表或快表存储器，以及用在数据库和知识库中。","multi":0,"questionType":1,"answer":"D","chooseItem":["796234809100750849"],"itemList":[{"id":"796234809012670465","questionId":"796234808094117889","content":" 顺序存取","answer":0,"chooseValue":"A"},{"id":"796234809046224897","questionId":"796234808094117889","content":" 直接存取","answer":0,"chooseValue":"B"},{"id":"796234809075585025","questionId":"796234808094117889","content":" 随机存取","answer":0,"chooseValue":"C"},{"id":"796234809100750849","questionId":"796234808094117889","content":" 相联存取","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235281819783169","title":"Cache的替换算法中，（16）算法计数器位数多，实现困难。","analyze":"本题考查计算机系统存储系统基础知识。<br>FIFO（First In First Out）遵循先入先出原则，若当前Cache被填满，则替换最早进入Cache的那个块。它的优点是比较容易实现，能够利用主存储器中页面调度情况的历史信息，但是没有反映程序的局部性。因为最先调入主存的页面，很可能也是经常要使用的页面。<br>LFU（Lease Frequently Used）算法将访问次数最少的内容替换出Cache。显然，这是一种非常合理的算法，因为到目前为止最少使用的页面，很可能也是将来最少访问的页面。该算法既充分利用了主存中页面调度情况的历史信息，又正确反映了程序的局部性。但是，这种算法实现起来非常困难，它要为每个页面设置一个很长的计数器，并且要选择一个固定的时钟为每个计数器定时计数。在选择被替换页面时，要从所有计数器中找出一个计数值最大的计数器。<br>LRU（Least Recently Used）算法是将最近最少使用的内容替换出Cache。该算法把LFU算法中要记录数量上的“多”与“少”简化成判断“有”与“无”，因此，实现起来比较容易。<br>RAND算法（Random algorithm）。利用软件或硬件的随机数发生器来确定主存储器中被替换的页面。这种算法最简单，而且容易实现。但是，这种算法完全没有利用主存储器中页面调度情况的历史信息，也没有反映程序的局部性，所以命中率比较低。","multi":0,"questionType":1,"answer":"B","chooseItem":["796235282776084481"],"itemList":[{"id":"796235282738335745","questionId":"796235281819783169","content":" FIFO","answer":0,"chooseValue":"A"},{"id":"796235282776084481","questionId":"796235281819783169","content":" LFU","answer":1,"chooseValue":"B"},{"id":"796235282809638913","questionId":"796235281819783169","content":" LRU","answer":0,"chooseValue":"C"},{"id":"796235282847387649","questionId":"796235281819783169","content":" RAND","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235046036983809","title":"流水线的吞吐率是指流水线在单位时间里所完成的任务数或输出的结果数。设某流水线有5段，有1段的时间为2ns ，另外4 段的每段时间为1ns，利用此流水线完成100个任务的吞吐率约为（ ）个/s 。","analyze":"本题考查计算机系统基础知识。<br>此流水线上完成100个任务的时间为2+4+2*99=204ns，完成100个任务的吞吐率为：(100/204)*10<sup>9</sup>=490*10<sup>6<br></sup>","multi":0,"questionType":1,"answer":"B","chooseItem":["796235047022645249"],"itemList":[{"id":"796235047010062337","questionId":"796235046036983809","content":" 500×10<sup>6</sup>","answer":0,"chooseValue":"A"},{"id":"796235047022645249","questionId":"796235046036983809","content":" 490×10<sup>6</sup>","answer":1,"chooseValue":"B"},{"id":"796235047031033857","questionId":"796235046036983809","content":" 250×10<sup>6</sup>","answer":0,"chooseValue":"C"},{"id":"796235047043616769","questionId":"796235046036983809","content":" 167×10<sup>6</sup>","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796233846386348033","title":"由于处理器芯片在不同领域应用时，需要考虑对环境的适应性。通常，我们把芯片分为民用级、工业级和军用级。（）分别是民用级、工业级和军用级芯片的标准工作温度范围。","analyze":"商业级0~+70℃；工业级-40~+85℃；汽车级-40~+125℃；军用级-55~+155℃","multi":0,"questionType":1,"answer":"C","chooseItem":["796233847510421505"],"itemList":[{"id":"796233847455895553","questionId":"796233846386348033","content":" -10℃ ~+70℃ 、-40℃~+80℃ 、-50℃+150℃","answer":0,"chooseValue":"A"},{"id":"796233847485255681","questionId":"796233846386348033","content":" 0℃~+70℃、-30℃~+85℃、-60℃~+150℃","answer":0,"chooseValue":"B"},{"id":"796233847510421505","questionId":"796233846386348033","content":" 0℃~+70℃、-40℃~+85℃、-55℃~+150℃","answer":1,"chooseValue":"C"},{"id":"796233847543975937","questionId":"796233846386348033","content":" 10℃~+60℃、-40℃~+90℃、 -55℃~+150℃","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234811097239553","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>计算机系统中，（16）方式是根据所访问的内容来决定要访问的存储单元，常用在（17）存储器中。","analyze":"本题考查计算机系统知识。<br>相联存储器是一种按内容访问的存储器。其工作原理就是把数据或数据的某一部分作为关键字，按顺序写入信息，读出时并行地将该关键字与存储器中的每一单元进行比较，找出存储器中所有与关键字相同的数据字，特别适合于信息的检索和更新，因此，相联存取方式是根据所访问的内容来决定要访问的存储单元。<br>相联存储器可用在高速缓冲存储器（Cache)中，在虚拟存储器中用来作为段表、页表或快表存储器，以及用在数据库和知识库中。","multi":0,"questionType":1,"answer":"B","chooseItem":["796234812061929473"],"itemList":[{"id":"796234812019986433","questionId":"796234811097239553","content":" DRAM","answer":0,"chooseValue":"A"},{"id":"796234812061929473","questionId":"796234811097239553","content":" Cache","answer":1,"chooseValue":"B"},{"id":"796234812082900993","questionId":"796234811097239553","content":" EEPROM","answer":0,"chooseValue":"C"},{"id":"796234812103872513","questionId":"796234811097239553","content":" CD-ROM","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235049270792193","title":"以下关于复杂指令集计算机(Complex Instruction Set Computer,CISC) 的叙述中，正确的是( )。","analyze":"本题考查计算机系统基础知识。<br>复杂指令集计算机（Complex Instruction Set Computer, CISC)与精简指令计算机(Reduced Instruction Set Computing, RISC)处理器的两种架构。<br>计算机性能提高的一种途径是通过增加硬件的复杂性来获得。随着集成电路技术，特别是VLSI (超大规模集成电路）技术的迅速发展，为了使软件编程更方便以及提高程序的运行速度，硬件工程师采用的办法是不断增加可实现复杂功能的指令和多种灵活的编址方式，甚至某些指令可支持将高级编程语言的语句归类后的复杂操作，致使硬件越来越复杂，造价也相应提高。为了实现复杂操作，微处理器除向程序员提供哥存器和机器指令功能外，还通过保存于只读存储器（ROM)中的微程序来实现其极强的功能，微处理器分析每一条指令之后执行一系列初级指令运算来完成所需的功能，这种设计的计算机被称为复杂指令集计算机（CISC)结构，一般CISC计算机所含的指令数目至少300条以上，有的甚至超过500条。<br>CISC存在许多缺点。在这种计算机中，各种指令的使用率相差悬殊。据统计，个典型程序的运算过程所使用的80%指令，只占一个处理器指令系统的20%。事实上最频繁使用的指令是取、存和加等最简单的指令，因此，长期致力于复杂指令系统的设计, 实际上是在设计一种难得在实践中用得上的指令系统的处理器。同时，复杂的指令系统必然带来结构的复杂性，既增加了设计时间与成本还容易造成设计失误。<br>针对CISC的这些弊病，帕特逊等人提出了精简指令的设想即指令系统应当只包含那些使用频率很高的少量指令，并提供一些必要的指令以支持操作系统和高级语言。按照这个原则发展的计算机被称为精简指令集计算机（RISC)结构。CISC与RISC正在逐步走向融合。","multi":0,"questionType":1,"answer":"D","chooseItem":["796235050298396673"],"itemList":[{"id":"796235050197733377","questionId":"796235049270792193","content":" 只设置使用频度高的一些简单指令，不同指令执行时间差别很小","answer":0,"chooseValue":"A"},{"id":"796235050243870721","questionId":"796235049270792193","content":" CPU中设置大量寄存器，利用率低","answer":0,"chooseValue":"B"},{"id":"796235050269036545","questionId":"796235049270792193","content":" 常采用执行速度更快的组合逻辑实现控制器","answer":0,"chooseValue":"C"},{"id":"796235050298396673","questionId":"796235049270792193","content":" 指令长度不固定，指令格式和寻址方式多","answer":1,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235284822904833","title":"以下关于总线的说法中，正确的是（17）。","analyze":"本题考查计算机系统基础知识。<br>串行总线将数据一位一位传输，数据线只需要一根（如果支持双向需要2根），并行总线是将数据的多位同时传输（4位，8位，甚至64位，128位），显然，并行总线的传输速度快，在长距离情况下成本高，串行传输的速度慢，但是远距离传输时串行成本低。<br>单总线结构在一个总线上适应不同种类的设备，通用性强，但是无法达到高的性能要求，而专用总线则可以与连接设备实现最佳匹配。<br>半双工通信是指数据可以沿两个方向传送，但同一时刻一个半双工总线结构，信道只允许单方向传送，因此又被称为双向交替通信。","multi":0,"questionType":1,"answer":"C","chooseItem":["796235285875675137"],"itemList":[{"id":"796235285812760577","questionId":"796235284822904833","content":" 串行总线适合近距离高速数据传输，但线间串扰会导致速率受限","answer":0,"chooseValue":"A"},{"id":"796235285842120705","questionId":"796235284822904833","content":" 并行总线适合长距离数据传输，易提高通信时钟频率来实现高速数据传输","answer":0,"chooseValue":"B"},{"id":"796235285875675137","questionId":"796235284822904833","content":" 单总线结构在一个总线上适应不同种类的设备，设计复杂导致性能降低","answer":1,"chooseValue":"C"},{"id":"796235285900840961","questionId":"796235284822904833","content":" 半双工总线只能在一个方向上传输信息","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235052215193601","title":"在高速缓存 (Cache) -主存储器构成的存储系统中，（ ）。","analyze":"本题考查计算机系统基础知识。<br>高速缓存（Cache)是随着CPU与主存之间性能见的差距不断增大而引入的，其速度比主存快得多，所存储的内容是CPU近期可能会需要的信息，是主存内容的副本，因此CPU需要访问数据和读取指令时要先访问Cache,若命中则直接访问，若不命中再去访问主存。CPU是按照访问主存的方式给出地址的，这就需要由硬件快速地将主存地址转换为Cache地址。","multi":0,"questionType":1,"answer":"A","chooseItem":["796235053142134785"],"itemList":[{"id":"796235053142134785","questionId":"796235052215193601","content":" 主存地址到Cache地址的变换由硬件完成，以提高速度","answer":1,"chooseValue":"A"},{"id":"796235053171494913","questionId":"796235052215193601","content":" 主存地址到Cache地址的变换由软件完成，以提高灵活性","answer":0,"chooseValue":"B"},{"id":"796235053196660737","questionId":"796235052215193601","content":" Cache 的命中率随其容量增大线性地提高","answer":0,"chooseValue":"C"},{"id":"796235053226020865","questionId":"796235052215193601","content":" Cache 的内容在任意时刻与主存内容完全一致","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234814108749825","title":"RISC指令系统的特点包括（ ）。<br>①指令数量少<br>②寻址方式多<br>③指令格式种类少<br>④指令长度固定","analyze":"本题考査计算机系统硬件知识。<br>RISC(Reduced Instruction Set Computer,精简指令集计算机）的基本思想赴通过减少指令总数和简化指令功能降低硬件设计的复杂度，使指令能单周期执行，并通过优化编译，提高指令的执行速度，采用硬布线控制逻辑优化编译程序等。<br>RISC的关键技术有重叠寄存器窗口技术、优化编译技术、超流水及超标量技术，将硬布线逻辑与微程序相结合在微程序技术中。","multi":0,"questionType":1,"answer":"C","chooseItem":["796234815098605569"],"itemList":[{"id":"796234815035691009","questionId":"796234814108749825","content":" ①②③","answer":0,"chooseValue":"A"},{"id":"796234815069245441","questionId":"796234814108749825","content":" ①②④","answer":0,"chooseValue":"B"},{"id":"796234815098605569","questionId":"796234814108749825","content":" ①③④","answer":1,"chooseValue":"C"},{"id":"796234815136354305","questionId":"796234814108749825","content":" ②③④","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235287947661313","title":"计算机系统中有多种实现数据输入和输出的控制方式，其中占用CPU时间最多的是（18）。","analyze":"本题考查计算机系统基础知识。<br>通过CPU执行程序来查询外设的状态，判断外设是否准备好接收数据或准备好了向CPU输入数据。根据这种状态，CPU有针对性地为外设的输入输出服务。该方式的缺点在于CPU必须等待I/O系统完成数据传输任务，在此期间CPU需定期地查询I/O系统的状态，以确认传输是否完成。因此，整个系统的性能严重下降。<br>当I/O系统与外设交换数据时，CPU无须等待也不必去查询I/O的状态，而可以抽身出来处理其他任务。当I/O系统准备好以后，则发出中断请求信号通知CPU，CPU接到中断请求信号后，保存正在执行程序的现场，转入I/O中断服务程序的执行，完成与I/O系统的数据交换，然后再返回被打断的程序继续执行。与程序控制方式相比，中断方式因为CPU无须等待而提高了效率。<br>DMA方式是指数据在内存与I/O设备间的直接成块传送，即在内存与I/O设备间传送-个数据块的过程中，不需要CPU的任何干涉，只需要CPU在过程开始启动（即向设备发出“传送一块数据”的命令）与过程结束（CPU通过轮询或中断得知过程是否结束和下次操作是否准备就绪）时的处理，数据传输处理由DMA硬件直接执行完成，CPU在此传送过程中可执行其他任务。<br>缓冲方式的说法比较笼统，是无效选项。","multi":0,"questionType":1,"answer":"A","chooseItem":["796235288874602497"],"itemList":[{"id":"796235288874602497","questionId":"796235287947661313","content":" 程序查询方式","answer":1,"chooseValue":"A"},{"id":"796235288895574017","questionId":"796235287947661313","content":" 中断方式","answer":0,"chooseValue":"B"},{"id":"796235288920739841","questionId":"796235287947661313","content":" DMA方式","answer":0,"chooseValue":"C"},{"id":"796235288945905665","questionId":"796235287947661313","content":" 缓冲方式","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235420483473409","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>使用Cache改善系统性能的依据是程序的局部性原理。程序中大部分指令是（60）的。设某计算机主存的读／写时间为100ns，有一个指令和数据合一的Cache，已知该Cache的读／写时间为10ns，取指令的命中率为98%，取数的命中率为95%。在执行某类程序时，约有1/5指令需要额外存／取一个操作数。假设指令流水线在任何时候都不阻塞，则设置Cache后，每条指令的平均读取时间约为（61）ns。","analyze":"在设计和开发系统程序和应用程序时，程序员通常采用模块化的程序设计方法。某一模块的程序，往往集中在存储器逻辑地址空间中很小的一块范围内，且程序地址分布是连续的。也就是说，CPU在一段较短的时间内，是对连续地址的一段很小的主存空间频繁地进行访问，而对此范围以外地址的访问甚少，这种现象称为程序访问的局部性=<br>基于程序访问的局部性原理，增加Cache使得要访问的数据绝大多数都可以在Cache中找到，这样才能在性能上使主存的平均读出时间尽可能接近Cache的读出时间。Cache的T作效率通常用“命中率”来表示。<br>命中率指的是CPU要访问的信息在Cache中的概率，Cache的命中率越高，CPU访问主存的速度就越接近访问Cache的速度。通常Cache的容量越大，存储的块也越多，CPU的命中率就越高。但是，当Cache的容量达到一定值时，命中率并不会随着容量的增大而增加，而且Cache容量的增大将导致成本的增加，所以，Cache的容量一般是命中率与成本价格的折衷。<br>在一个程序执行期间，设N<sub>c</sub>表示Cache完成存取的总次数，N<sub>m</sub>表示主存完成存取的总次数，h定义为命中率，则有<br><img alt=\"\" width=\"118\" height=\"53\" src=\"https://image.chaiding.com/ruankao/187a2f8ba7e9b0df0cbd89c7aedbaffc.jpg?x-oss-process=style/ruankaodaren\"><br>若t<sub>c</sub>表示命中时的Cache访问时间，t<sub>m</sub>表示未命中时的主存访问时间，1-h表示未命中率，则Cache—主存系统的平均访问时间t<sub>a</sub>为：<br>t<sub>a</sub>=ht<sub>c</sub>+（1-h）t<sub>m</sub><br></br>（100*2%+10*98%）+（100*5%+10*95%）*20%=14.7","multi":0,"questionType":1,"answer":"A","chooseItem":["796235421456551937"],"itemList":[{"id":"796235421456551937","questionId":"796235420483473409","content":" 顺序存储、顺序执行","answer":1,"chooseValue":"A"},{"id":"796235421490106369","questionId":"796235420483473409","content":" 随机存储、顺序执行","answer":0,"chooseValue":"B"},{"id":"796235421519466497","questionId":"796235420483473409","content":" 顺序存储、随机执行","answer":0,"chooseValue":"C"},{"id":"796235421548826625","questionId":"796235420483473409","content":" 随机存储、随机执行","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796235423566286849","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>使用Cache改善系统性能的依据是程序的局部性原理。程序中大部分指令是（60）的。设某计算机主存的读／写时间为100ns，有一个指令和数据合一的Cache，已知该Cache的读／写时间为10ns，取指令的命中率为98%，取数的命中率为95%。在执行某类程序时，约有1/5指令需要额外存／取一个操作数。假设指令流水线在任何时候都不阻塞，则设置Cache后，每条指令的平均读取时间约为（61）ns。","analyze":"在设计和开发系统程序和应用程序时，程序员通常采用模块化的程序设计方法。某一模块的程序，往往集中在存储器逻辑地址空间中很小的一块范围内，且程序地址分布是连续的。也就是说，CPU在一段较短的时间内，是对连续地址的一段很小的主存空间频繁地进行访问，而对此范围以外地址的访问甚少，这种现象称为程序访问的局部性=<br>基于程序访问的局部性原理，增加Cache使得要访问的数据绝大多数都可以在Cache中找到，这样才能在性能上使主存的平均读出时间尽可能接近Cache的读出时间。Cache的T作效率通常用“命中率”来表示。<br>命中率指的是CPU要访问的信息在Cache中的概率，Cache的命中率越高，CPU访问主存的速度就越接近访问Cache的速度。通常Cache的容量越大，存储的块也越多，CPU的命中率就越高。但是，当Cache的容量达到一定值时，命中率并不会随着容量的增大而增加，而且Cache容量的增大将导致成本的增加，所以，Cache的容量一般是命中率与成本价格的折衷。<br>在一个程序执行期间，设N<sub>c</sub>表示Cache完成存取的总次数，N<sub>m</sub>表示主存完成存取的总次数，h定义为命中率，则有<br><img alt=\"\" width=\"118\" height=\"53\" src=\"https://image.chaiding.com/ruankao/9394772ce0b23e004ba7e0f7a7614c7d.jpg?x-oss-process=style/ruankaodaren\"><br>若t<sub>c</sub>表示命中时的Cache访问时间，t<sub>m</sub>表示未命中时的主存访问时间，1-h表示未命中率，则Cache—主存系统的平均访问时间t<sub>a</sub>为：<br>t<sub>a</sub>=ht<sub>c</sub>+（1-h）t<sub>m</sub><br></br>（100*2%+10*98%）+（100*5%+10*95%）*20%=14.7","multi":0,"questionType":1,"answer":"B","chooseItem":["796235424522588161"],"itemList":[{"id":"796235424493228033","questionId":"796235423566286849","content":" 12.3","answer":0,"chooseValue":"A"},{"id":"796235424522588161","questionId":"796235423566286849","content":" 14.7","answer":1,"chooseValue":"B"},{"id":"796235424547753985","questionId":"796235423566286849","content":" 23.4","answer":0,"chooseValue":"C"},{"id":"796235424577114113","questionId":"796235423566286849","content":" 26.3","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234467910897665","title":"<p><strong>请作答第<span style=\"color: red\">1</span>个空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks，RAID)机制中共分（61）级别，RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中，(62)是无冗余和无校验的数据分块：(63)由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘空间利用率只有50%；(64)是具有独立的数据硬盘与两个独立的分布式校验方案。","analyze":"本题考查磁盘冗余阵列的相关知识。<br> 廉价磁盘冗余阵列简称硬盘阵列，其基本思想就是把多个相对便宜的硬盘组合起来，成为一个硬盘阵列组，使性能达到甚至超过一个价格昂贵、容量巨大的硬盘。根据选择的版本不同，RAID比单颗硬盘具有的好处是：增强资料整合度，增强容错功能，增加处理量或容量。RAID把多个硬盘组合成为一个逻辑磁区，因此，操作系统只会把它当作一个硬盘。也就是说，磁盘阵列对于电脑来说，看起来就像一个单独的硬盘或逻辑存储单元。FAID分为不同的等级，包括RAID 0, RAID1, RAID 1E, RAID 5, RAID 6, RAID 7, RAID 10, RAID 50。每种等级都有其理论上的优缺点，不同的等级在两个目标间取得平衡，分别是增加资料可靠性以及增加存储器（群）读写效能。<br> RAID 0级是无冗余和无校验的数据分块；RAID 1级由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘交间利用率只有50%; RAID 6级是具有独立的数据硬盘与两个独立的分布式校验方案。","multi":0,"questionType":1,"answer":"B","chooseItem":["796234469001416705"],"itemList":[{"id":"796234468959473665","questionId":"796234467910897665","content":" 7个","answer":0,"chooseValue":"A"},{"id":"796234469001416705","questionId":"796234467910897665","content":" 8个","answer":1,"chooseValue":"B"},{"id":"796234469047554049","questionId":"796234467910897665","content":" 6个","answer":0,"chooseValue":"C"},{"id":"796234469068525569","questionId":"796234467910897665","content":" 9个","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234472222642177","title":"<p><strong>请作答第<span style=\"color: red\">2</span>个空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks，RAID)机制中共分（61）级别，RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中，(62)是无冗余和无校验的数据分块：(63)由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘空间利用率只有50%；(64)是具有独立的数据硬盘与两个独立的分布式校验方案。","analyze":"本题考查磁盘冗余阵列的相关知识。<br> 廉价磁盘冗余阵列简称硬盘阵列，其基本思想就是把多个相对便宜的硬盘组合起来，成为一个硬盘阵列组，使性能达到甚至超过一个价格昂贵、容量巨大的硬盘。根据选择的版本不同，RAID比单颗硬盘具有的好处是：增强资料整合度，增强容错功能，增加处理量或容量。RAID把多个硬盘组合成为一个逻辑磁区，因此，操作系统只会把它当作一个硬盘。也就是说，磁盘阵列对于电脑来说，看起来就像一个单独的硬盘或逻辑存储单元。FAID分为不同的等级，包括RAID 0, RAID1, RAID 1E, RAID 5, RAID 6, RAID 7, RAID 10, RAID 50。每种等级都有其理论上的优缺点，不同的等级在两个目标间取得平衡，分别是增加资料可靠性以及增加存储器（群）读写效能。<br> RAID 0级是无冗余和无校验的数据分块；RAID 1级由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘交间利用率只有50%; RAID 6级是具有独立的数据硬盘与两个独立的分布式校验方案。","multi":0,"questionType":1,"answer":"A","chooseItem":["796234473376075777"],"itemList":[{"id":"796234473376075777","questionId":"796234472222642177","content":" RAID 0级","answer":1,"chooseValue":"A"},{"id":"796234473422213121","questionId":"796234472222642177","content":" RAID 1级","answer":0,"chooseValue":"B"},{"id":"796234473464156161","questionId":"796234472222642177","content":" RAID 2级","answer":0,"chooseValue":"C"},{"id":"796234473485127681","questionId":"796234472222642177","content":" RAID 3级","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234475540336641","title":"<p><strong>请作答第<span style=\"color: red\">3</span>个空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks，RAID)机制中共分（61）级别，RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中，(62)是无冗余和无校验的数据分块：(63)由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘空间利用率只有50%；(64)是具有独立的数据硬盘与两个独立的分布式校验方案。","analyze":"本题考查磁盘冗余阵列的相关知识。<br> 廉价磁盘冗余阵列简称硬盘阵列，其基本思想就是把多个相对便宜的硬盘组合起来，成为一个硬盘阵列组，使性能达到甚至超过一个价格昂贵、容量巨大的硬盘。根据选择的版本不同，RAID比单颗硬盘具有的好处是：增强资料整合度，增强容错功能，增加处理量或容量。RAID把多个硬盘组合成为一个逻辑磁区，因此，操作系统只会把它当作一个硬盘。也就是说，磁盘阵列对于电脑来说，看起来就像一个单独的硬盘或逻辑存储单元。FAID分为不同的等级，包括RAID 0, RAID1, RAID 1E, RAID 5, RAID 6, RAID 7, RAID 10, RAID 50。每种等级都有其理论上的优缺点，不同的等级在两个目标间取得平衡，分别是增加资料可靠性以及增加存储器（群）读写效能。<br> RAID 0级是无冗余和无校验的数据分块；RAID 1级由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘交间利用率只有50%; RAID 6级是具有独立的数据硬盘与两个独立的分布式校验方案。","multi":0,"questionType":1,"answer":"B","chooseItem":["796234476500832257"],"itemList":[{"id":"796234476484055041","questionId":"796234475540336641","content":" RAID 4级","answer":0,"chooseValue":"A"},{"id":"796234476500832257","questionId":"796234475540336641","content":" RAID 1级","answer":1,"chooseValue":"B"},{"id":"796234476525998081","questionId":"796234475540336641","content":" RAID 3级","answer":0,"chooseValue":"C"},{"id":"796234476546969601","questionId":"796234475540336641","content":" RAID 2级","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234478514098177","title":"<p><strong>请作答第<span style=\"color: red\">4</span>个空。</strong></p>磁盘冗余阵列（Redundant Array of Inexpensive Disks，RAID)机制中共分（61）级别，RAID应用的主要技术有分块技术、交叉技术和重聚技术。其中，(62)是无冗余和无校验的数据分块：(63)由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘空间利用率只有50%；(64)是具有独立的数据硬盘与两个独立的分布式校验方案。","analyze":"本题考查磁盘冗余阵列的相关知识。<br> 廉价磁盘冗余阵列简称硬盘阵列，其基本思想就是把多个相对便宜的硬盘组合起来，成为一个硬盘阵列组，使性能达到甚至超过一个价格昂贵、容量巨大的硬盘。根据选择的版本不同，RAID比单颗硬盘具有的好处是：增强资料整合度，增强容错功能，增加处理量或容量。RAID把多个硬盘组合成为一个逻辑磁区，因此，操作系统只会把它当作一个硬盘。也就是说，磁盘阵列对于电脑来说，看起来就像一个单独的硬盘或逻辑存储单元。FAID分为不同的等级，包括RAID 0, RAID1, RAID 1E, RAID 5, RAID 6, RAID 7, RAID 10, RAID 50。每种等级都有其理论上的优缺点，不同的等级在两个目标间取得平衡，分别是增加资料可靠性以及增加存储器（群）读写效能。<br> RAID 0级是无冗余和无校验的数据分块；RAID 1级由磁盘对组成，每一个工作盘都有其对应的镜像盘，上面保存着与工作盘完全相同的数据拷贝，具有最高的安全性，但磁盘交间利用率只有50%; RAID 6级是具有独立的数据硬盘与两个独立的分布式校验方案。","multi":0,"questionType":1,"answer":"A","chooseItem":["796234479512342529"],"itemList":[{"id":"796234479512342529","questionId":"796234478514098177","content":" RAID 6级","answer":1,"chooseValue":"A"},{"id":"796234479550091265","questionId":"796234478514098177","content":" RAID 5级","answer":0,"chooseValue":"B"},{"id":"796234479579451393","questionId":"796234478514098177","content":" RAID 4级","answer":0,"chooseValue":"C"},{"id":"796234479613005825","questionId":"796234478514098177","content":" RAID 3级","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null},{"id":"796234972536000513","title":"假如有3块80T的硬盘，采用RAID5的容量是（ ）。","analyze":"本试题考查RAID存储。<br>3块80T的硬盘，2块用作备份，1块用作冗余，故容量为160T。","multi":0,"questionType":1,"answer":"C","chooseItem":["796234973559410689"],"itemList":[{"id":"796234973496496129","questionId":"796234972536000513","content":" 40T","answer":0,"chooseValue":"A"},{"id":"796234973525856257","questionId":"796234972536000513","content":" 80T","answer":0,"chooseValue":"B"},{"id":"796234973559410689","questionId":"796234972536000513","content":" 160T","answer":1,"chooseValue":"C"},{"id":"796234973588770817","questionId":"796234972536000513","content":" 240T","answer":0,"chooseValue":"D"}],"userAnswer":null,"userChooseItem":null,"answerCorrect":null,"userCollect":null}]}}
