信息科学与电子工程专业英语课后答案

信息科学与电子工程专业英语课后答案 科技英语 课件 超市陈列培训课件免费下载搭石ppt课件免费下载公安保密教育课件下载病媒生物防治课件 可下载高中数学必修四课件打包下载 Exercises Unit 1 Exercises Unit 1 Exercises (1) Translate the following sentences into Chinese. (1) Translate the following sentences into Chinese. 1. As with series resonance, the greater the resistance in the circuit the lower the Q and, accordingly, the flatter and broader the resonance curve of either line current or circuit impedance. 对于串联谐振，电路中的电阻愈大Q值就愈低，相应 地线路电流或电路阻抗的谐振曲线也就愈平、愈宽。 2. A wire carrying a current looks exactly the same and weighs exactly the same as it does when it is not carrying a current. 一根带电的导线其外表与重量都与不带电导线完全一 样。 3. Click mouse on the waveform and drag it to change the pulse repetition rate, or directly enter a new value of the period in the provided dialogue box, while keeping the pulse width unchanged. 在波形上点击鼠标并拖动来改变脉冲重复频率，或者在 提供的对话框中直接输入新的周期值，而保持脉冲宽度 1 HMILYYLIMH 科技英语课件 Exercises 不变。 4. Electronics is the science and the technology of the passage of charged particles in a gas, in a vacuum, or in a semiconductor. Please note that particle motion confined within a metal only is not considered electronics. 电子学是一门有关带电粒子在气体、真空或半导体中运 动的科学技术。注意，在本书中粒子运动仅限于金属的 情况不属于电子学。 5. Hardware technologies have played vital roles in our ability to use electronic properties to process information, but software and data processing aspects have not developed at the same speed. 硬件技术在我们使用电子特性来处理信息的能力中一 直起着重要作用，而软件及数字处理方面却没能与硬件 同步发展。 6. However, in a properly designed DC amplifier the effect of transistor parameter variation, other than Ico, may be practically eliminated if the operation point of each stage is adjusted so that it remains in the linear operation range 2 HMILYYLIMH 科技英语课件 Exercises of the transistor as temperature varies. 然而在设计得当的直流放大器中，若调节每一级的工作 点使之在温度变化时保持在晶体管线性区，就能在实际 上消除Ico以外的晶体管参数变化所造成的影响。 Unit 2 Exercises Unit 2 Exercises (1) Translate the following sentences into Chinese. (1) Translate the following sentences into Chinese. 1. If analog signals are to be transmitted digitally, they first have to be sampled at a specified rate and further converted to discrete amplitude samples by quantization. 如果要以数字方式传输模拟信号，首先必须以一定的频 率对信号进行采样，然后通过量化进一步将它们转换为 离散的幅度样本。 2. Linear filters amplify or attenuate selected spatial frequencies, can achieve such effects as smoothing and sharpening, and usually form the basis of re-sampling and boundary detection algorithms. 线性滤波器放大或衰减选择的空间频率，能够实现像 平滑和锐化这些效果，通常是重采样和边缘检测算法 的基础。 3 HMILYYLIMH 科技英语课件 Exercises 3. Stability and repeatability are fundamental attributes of digital circuits, however, and the necessary accuracy can be obtained in a digital version of the modulator by an appropriate choice of word length to represent the signals. 不过稳定性和可重复性是数字电路的基本性质，在数字 式调制器中必要的精度可通过适当地选择代表信号的字 长而获得。 4. The first observation is made on the fundamental relationship between the nature of system and the periodicity of its frequency response: a continuous system has an aperiodic frequency response, while a discrete system has a periodic frequency response. 从系统性质和它频率响应的周期性之间的基本关系中 首先可以看到:连续系统有非周期性的频率响应，而离 散系统有周期性的频率响应。 5. The main function of the receiver is to extract the input message signal from the degraded version of the transmitted signal coming from the channel. 接收器的主要功能是从由信道传输来的退化了的信号中 提取出输入消息。 4 HMILYYLIMH 科技英语课件 Exercises Unit 3 Exercises (1) Translate the following sentences into Chinese. (1) Translate the following sentences into Chinese. 1. A very commonly used method of microwave measurements is based on the study of a standing wave pattern formed along the line because of the interference of incident and reflected waves. 一个很常用的微波测量方法是基于对驻波图型的研究， 这种驻波是由入射波和反射波之间的干涉而沿着传输 线形成的。 2. Computations show a reduction of 6dB in the EM field intensity with the distance doubled, and an increase of 3dB in the intensity with the transmitted power doubled. This result provides verification to the algorithm used. 计算表明，当距离增大一倍时，电磁场强度减小6分贝; 而发射功率增大一倍时，场强则增加3分贝。这一结果 验证了所用算法的正确性。 3. Like transfer of heat by conduction, convection and radiation, microwave heating can be considered as another mode of heat transfer, in which heat is produced directly at 5 HMILYYLIMH 科技英语课件 Exercises the location of the dielectric losses. 就像通过传导、对流、辐射来传递热量一样，微波加热 可以看作热传递的另一种方式，即热量直接产生于发生 介电损耗的地方。 4. Operation of the radar is based on the measurement of the time it takes for a pulse transmitted from an antenna to get reflected by the object to be detected and to return at the antenna and the receiver. 雷达的工作是基于对天线发出的脉冲被所要探测的目 标反射，(然后)回到天线和接收机所需时间的测量。 5. Other motivations for using CAD in circuit design includes the wish to acquire confidence in a design that was accomplished by other means, and, not least in importance, a sense of curiosity or perhaps a desire to discover the unexpected. 在电路设计中使用CAD的其它动机包括:想要验证用 别的方法设计出来的电路;满足好奇心或者可能是想发 现预想不到的现象。后一个动机并非是最不重要的。(取 得信心，并非最不重要，意料之外的事) 6 HMILYYLIMH 科技英语课件 Exercises 6. The spacing between the repeating amplifiers is a function of the cable attenuation and the system bandwidth so that the gain provided by these amplifiers compensates for the loss introduced by the cable. 中继放大器之间的间距是电缆衰减和系统带宽的函数， 以便这些放大器提供的增益补偿电缆引起的损耗。 7. When the cut-off frequency is no less than the maximal frequency of the original signal, nor is it greater than the difference between the sampling frequency and the maximal frequency, the original signal may be completely rebuilt. 当截止频率不小于原始信号的最高频率，也不大于采样 频率和最高频率之差，原始信号可以完整地重建。 8. While the politics of the last one hundred years centered around Industrial Age technology, the politics of the future will be based on Information Age concerns oriented towards the storage, protection and exchange of information. 尽管近百年来的政治活动是以工业时代的技术为中心 的，未来的政治活动将基于信息时代的事物，面向信息 7 HMILYYLIMH 科技英语课件 Exercises 的存储、保护和交换。 Unit 4 Exercises Unit 4 Exercises (1) Translate the following passages into Chinese. (1) Translate the following passages into Chinese. 1. Communication may be broadly defined as the transfer of information from one point to another. When the information is to be conveyed over any distance a communication system is usually required. Within a communication system the information transfer is frequently achieved by superimposing or modulating the information on to an electromagnetic wave which acts as a carrier for the information signal. This modulated carrier is then transmitted to the required destination where it is received and the original information signal is obtained by demodulation. Sophisticated techniques have been developed for this process by using electromagnetic carrier waves operating at radio frequencies as well as microwave and millimeter wave frequencies. However, communication may also be achieved by using an electromagnetic carrier that is selected from the optical range of frequencies. 通信可以广义地定义为从一处到另一处的信息传递。当 8 HMILYYLIMH 科技英语课件 Exercises 要将信息传输到任何距离以外时就需要有一个通信系 统。在通信系统内部，信息的传输经常通过将信息叠加 或调制到作为信号载体的电磁波上来实现。经调制的载 波然后被传送到要求的目的地，在那里被接收，原始信 号通过解调被恢复出来。为了实现这一过程，已经利用 工作在射频、微波以及毫米波频率上的电磁载波开发了 复杂的技术。不过通信也可以用光波频段上的电磁载波 来实现。 2. Electronic communications is the transfer and movement of data between locations through the use of computers. An electronic communication system includes the equipment needed to support the movement of information, the communication lines and media to carry the information, the computer software and programs to control the flow of information, the personnel to plan, implement, and operate communications, and the management of all these resources. Electronic communications establishes links between people as well as computers. 电子通信就是通过使用计算机在不同的地点之间传输 数据。一个电子通信系统包括:支持信息流动所需要的 设备，承载信息的通信线路和媒介，控制信息流的计算 9 HMILYYLIMH 科技英语课件 Exercises 机软件和程序，计划、实施、操作通信系统的人员，以 及对所有这些资源的管理。电子通信建立起人和人、计 算机和计算机之间的联系。 3. First generation communications systems can be characterized by the use of analog transmission techniques, and the use of simple multiplex access techniques such as frequency division multiple access (FDMA). They suffered from a low user capacity, and security problems due to the simple radio interface used. Second generation systems were introduced in the early 1990’s, and all use digital technology. This provided an increase in the user capacity of around three times, achieved by compressing the voice waveforms before transmission. Third generation systems are an extension on the complexity of second-generation systems and are to be introduced after the year 2000. The system capacity will be increased to over ten times original first generation systems, achieved by using complex multiplex access techniques such as code division multiplex access (CDMA), or an extension of TDMA, and by improving flexibility of services available. 第一代通信系统以模拟传输技术和简单复用技术如频 10 HMILYYLIMH 科技英语课件 Exercises 分复用为特征。这些系统用户容量低，而且因为使用简 单的无线电接口而存在安全问题。第二代通信系统于20 世纪90年代初开始引入，全部使用数字技术。通过在 传输前将话音波形压缩使得用户容量提高了三倍。第三 代通信系统是对第二代系统在复杂性方面的扩展，预计 于2000年以后启用。通过使用复杂的复用技术如CDMA 或TDMA的扩展，并提高服务的灵活性使得系统容量比 原来的第一代系统提高10倍。 4. For each combination of communication (modulation/detection) type, channel fading model, and diversity type, the average bit error rate (BER) and/or symbol error rate (SER) of the system is obtained and represented by an expression in a form that can readily be evaluated. All cases considered correspond to real practical channels, and in many instances the BER and SER expressions obtained can be evaluated numerically on a hand-held calculator. 对于通信(调制/检测)类型、信道衰落模型、分集类型 的每一种组合，得到系统的平均误码率(BER)和符号 错误率(SER)，并以容易求值的形式表示。所有考虑的 相应于实际信道的情况，以及许多情况下得到的BER和 11 HMILYYLIMH 科技英语课件 Exercises SER表达式均可用手持计算器来计算。 5. Modulation is the systematic variation of some attribute of a carrier waveform such as the amplitude, phase, or frequency in accordance with a function of the message signal. It is used in communication systems for matching signal characteristics to channel characteristics, for reducing noise and interference, for simultaneously transmitting several signals over a single channel, and for overcoming some equipment limitations. A considerable portion of this book is devoted to the study of how modulation schemes are deigned to achieve the above tasks. The success of a communication system depends to a large extent on the modulation. 调制是载波波形的某些属性，例如幅度、相位和频率， 根据消息信号的函数有规则的变化。它用于通信系统以 使信号特性匹配信道特性，减少噪声和干扰，在单个信 道上同时传输多个信号，并克服某些设备的限制。本书 相当大部分内容是研究如何设计调制 方案 气瓶 现场处置方案 .pdf气瓶 现场处置方案 .doc见习基地管理方案.doc关于群访事件的化解方案建筑工地扬尘治理专项方案下载 以实现上述 任务。一个通信系统的成功很大程度上依赖于调制。 12 HMILYYLIMH 科技英语课件 Exercises Unit 5 Exercises (1) Translate the following passage into Chinese. (1) Translate the following passage into Chinese. OFDM consists of a large number of subcarriers equally spaced in a frequency band, each may be digitally modulated by a same scheme such as PSK, QAM, etc., or by different schemes. A serially transmitted sequence is divided into a number of sections, each having N symbols, and the N symbols in each section are used to modulate N carriers for simultaneous transmission. Therefore OFDM is essentially a parallel modulation system. When the number of subcarriers is sufficiently large, the system can resist multipath interference. This is because that, in the time domain, a symbol duration longer than the multipath delay can be chosen, while in the frequency domain, each symbol only occupies a small portion of the channel’s frequency band. Thus, the effect of multipath fading spreads over many symbols, resulting in slight distortion to many symbols rather than complete destroy of a few symbols. In this way, correct demodulation is not affected so that the signal can be accurately recovered at the receiver. In an OFDM system, the principle of choosing the subcarrier interval is to make the subcarriers mutually orthogonal within 13 HMILYYLIMH 科技英语课件 Exercises the entire symbol period. Thus, even if spectral overlap exists between the subcarriers, the symbols can still be recovered without loss. In order to realize maximum spectral efficiency, the interval between subcarriers is usually chosen to equal the reciprocal of the symbol duration T. Therefore the subcarrier frequencies in the base band are f= n/T, (n = 0, 1, ... , N,1). n Denoting the n-th modulating symbol as X(n), the OFDM waveform within a symbol duration can be expressed as: N,1n,, (1) x(t),X(n)expj2,t,0,t,T,,,T,,n,0 Sampling this waveform at t = T/N yields N,1N,1kTnk,,,, (2) x(k),X(n)expj2,,X(n)expj2,,k,1,2,？,N,1,,,,,,NN,,,,n,0n,0 It is observed from the above expression that x(k) and X(n) form a discrete Fourier transform pair, therefore the baseband OFDM waveform can be generated from the discrete Fourier mtransform of N modulating symbols. When N=2 where m is an integer, the fast algorithm of IDFT is easy to implement. OFDM由大量在频率上等间隔的子载波构成。每个子载波 可用同样的方案，如PSK，QAM等，或者用不同的方案数字 调制。将串行传输的符号序列分成许多段，每一段有N个符 14 HMILYYLIMH 科技英语课件 Exercises 号，每段的N个符号被用来分别调制N个载波同时发送。因此，OFDM本质上是一个并行调制系统，当载波数足够大时，这种系统具有抗多径干扰的能力。这是因为在时域上符号周期能选取得比多径延迟时间长，而在频域上每个符号只占整个信道带宽的一小部分，因此多径衰落的影响被分散到许多符号上，其结果是许多符号都发生轻度的畸变，而不是使某些符号被完全破坏。这样，不影响正确的解调，信号能在接收器中准确地恢复。 在OFDM系统中，选择子载波间隔的原则是使子载波在整个符号周期内相互正交，这样。即使在子载波间存在频谱部分重叠，符号仍能无损失地恢复。为了实现最大的频谱效率，子载波之间的间隔通常选取为符号周期的倒数。因此基带子载波频率为f= n/T, (n = 0, 1, ... , N,1)，第n个调制符号记为n X(n)，在一个符号周期内的OFDM波形可表示: N,1n,, (1) x(t),X(n)expj2,t,0,t,T,,,T,,n,0 在t = T/N 时刻采样这个波形得到: N,1N,1kTnk,,,, (2) x(k),X(n)expj2,,X(n)expj2,,k,1,2,？,N,1,,,,,,NN,,,,n,0n,0 从上面的表示中可以看到，x(k) 和X(n)构成了一对离散傅里叶变换，因此基带OFDM波形可根据N个调制符号的离散 15 HMILYYLIMH 科技英语课件 Exercises m傅里叶变换来生成。当N=2，其中m为整数，IDFT的快速算 法很容易实现。 Unit 6 Exercises (1) Translate the following sentences into Chinese. (1) Translate the following sentences into Chinese. 1. Communication is the transmission of information from one point to another. This transmission requires the ability to vary signals with time in a manner which is unpredictable to the receiver. 通信就是信息从一点传送到另一点。这种传送要求信号 随时间发生的变化不能在接收端预测。 2. It is true of any communication system that the shape and amplitude of the transmitted signal will be continuously degraded by the introduction of noise, and the attenuation along the transmission path. 传输的信号会不断地被噪声的引入和线路上的衰减所损 伤，对任何通信系统都是如此。 3. Since the very beginning, communications systems have consisted of three major parts, namely, the equipment, the medium, and the protocol. It is still the case today. 16 HMILYYLIMH 科技英语课件 Exercises However, the close link of telecommunications with the computer technology has brought about tremendous changes in communications, from the concepts, to the contents and the methods. 从一开始通信系统就由设备、媒介和协议三个要素组成。 至今依然如此。然而电信与计算机技术的紧密联系使得 通信从概念到内容和手段都发生了重大的变化。 4. The availability of such a large collection of system performance curves in a single compilation allows the researcher or system designer to perform trade-off studies among the various communication type/fading channel/diversity combinations so as to determine the optimum choice in the face of his or her available constraints. 在一本书中提供如此大量的系统性能曲线，使研究者或 系统设计者能在各种通信类型、衰落信道、分集组合之 间进行比较研究，从而在他或她所面临的限制之下做出 最佳的选择。 5. The channel provides the electrical connection between the information source and the user. The channel can have many different forms such as a microwave radio link over 17 HMILYYLIMH 科技英语课件 Exercises free space, a pair of wires, or an optical fiber. 信道提供信息源和用户之间的电路联接。信道可以有许 多不同的形式，比如自由空间里的微波联接，一对电线， 或者一根光纤。 6. The degradation of the transmitted signal is a result of signal distortion due to imperfect response of the channel and due to undesirable electrical signals (noise) and interference. Noise and signal distortion are two basic problems of electrical communication. 传输信号的退化是信号失真的结果，而这种失真又是由 信道的非理想响应及不想要的电信号(噪声)和干扰引 起的。噪声和信号畸变是电子通信的两个基本问题。 Unit 8 Exercises (1) Translate the following sentences into Chinese. (1) Translate the following sentences into Chinese. 1. Early in the twentieth century, it was found that light could cause atoms to emit electrons and that, when light released an electron from an atom, the energy possessed by the electron very greatly exceeded that which the atom could, according to the electromagnetic wave theory, have received. 18 HMILYYLIMH 科技英语课件 Exercises 在二十世纪早期，人们发现光能够使原子放出电子，而 且当光从原子中释放一个电子时，电子所包含的能量大 大超过由电磁波理论得到的原子所接收的能量。 2. Pulse broadening determines the minimum separation between adjacent pulses, which in turn determines the maximum information-carrying capacity of the optical fiber. 脉冲的展宽决定了相邻脉冲之间的最小间隔，这一间隔 进而又决定了光纤的最大信息容量。 3. If one were to transmit such information without impressing it on an optical carrier but instead on a radio frequency (RF) carrier a bit higher than the maximum rate, the transmission wavelength of the RF carrier would be centimeters or larger. 如果传输这样的信息不是将它加载到光纤上，而是加载 在略高于最大速率的射频载波上，则此射频载波就会是 厘米波或是波长更长一些的波。 4. The smallness of the optical wavelength, therefore, allows for the miniaturization of transmit and receive modules, which should allow considerable reduction in size, weight, and cost of optical communication systems with respect to 19 HMILYYLIMH 科技英语课件 Exercises microwave/radio wave counterparts. 光波波长之小使发射和接收模块得以小型化，这就使光 通信系统的尺寸、重量以至价格与相应的微波、无线电 波通信系统相比都大为降低。 5. Although all the advantages of coherent optical communication systems have yet to be brought to fruition, another property of optical radiation has made today’s optical communication systems not desirable for applications. 虽然相干光通信系统的所有优点还有待于落实在具体成 果中，光辐射的另一性质却使目前的光通信系统不利于 应用。 6. When coupled with light’s short wavelength which allows for miniature sources and detectors and micron-sized waveguides, direct detection schemes have allowed for small, lightweight, high bandwidth systems which are competitive in many areas, most notably to the present telecommunications transmission, although a myriad of other applications are continually opening up. 光的波长很小，可以使用小型的光源和检测器以及微米 级的波导，于是用直接检测方案可实现在许多领域具有 20 HMILYYLIMH 科技英语课件 Exercises 竞争力的小巧的宽带系统，这些领域中特别引人注目的 是当前电信传输中的应用，尽管无数其他应用也在不断 涌现出来。 7. As mentioned previously, these applications have tended to open up more slowly than originally predicted, as cost was really not much of a consideration in telecommunications, where equipment costs are swamped by other considerations. 如前所述，(线路)成本并非电信系统中真正重要的考虑 因素，通信设备的成本主要受到其他因素的制约，因此 这些应用比预料的出现得慢。 8. As wavelengths decrease to approach the size of circuit components, circuit elements are no longer lumped as such, and leads can act as reflective components and/or antennas and lumped elements as electromagnetic resonators. 随着波长减小到接近于电路元件的尺寸，电路 单元 初级会计实务单元训练题天津单元检测卷六年级下册数学单元教学设计框架单元教学设计的基本步骤主题单元教学设计 就不 再是集总的，导线可起到反射元件以及(或)天线的作 用，集总单元则成为电磁谐振器。 21 HMILYYLIMH 科技英语课件 Exercises UNIT 10 1.The principles which underlie almost all digital audio applications and devices, be they digital synthesis, sampling, digital recording or CD or iPod playback, are based on the basic concepts which follow in this chapter. New forms of playback, file formats, compression and storage of data are all changing on a seemingly daily basis, but the underlying mechanisms for converting real-world sound into digital values, manipulating those data and finally converting them back into real-world sound has not varied much since Max Mathews developed MUSIC I in 1957 at Bell Labs. 所有的数字音频应用程序和设备是在数字合成、采样、数字 录音或CD或iPod播放的基础上，都是基于最基本的概念, 遵循在这一章的原则。新形式的播放,文件格式,压缩和存储 的数据都在一个看似每天改变，但是这种联系的潜在机制转 换为现实世界的声音转化为数字值,操纵这些数据,最后将他 们转化成真实世界的声音没有变化多少，因为马克斯?马修 斯在贝尔实验室于开发了音乐于20世纪60年代。 22 HMILYYLIMH 科技英语课件 Exercises 2.Sound is created by vibrations, such as those produced by a guitar string, vocal cords or a speaker cone. These vibrations move the air molecules near them, forcing molecules together, as a result raising the air pressure slightly. The air molecules that are under pressure then push on air molecules surrounding them, which push on the next set of air molecules, and so forth, causing a wave of high pressure to move through the air; as high pressure waves move through the air, they leave low pressure areas behind them. When these pressure lows and highs – or waves – reach us, they vibrate the receptors in our ears, and we hear the vibrations as sound. 声音是由振动产生的,如制作的吉他弦,声带或扬声器锥。这 些振动移动附近的空气分子，使分子连接在一起，因此提高 空气压力略。这是在压力下将空气分子周围的空气分子，从 而推动下一组空气分子等等,导致一波高压进入空气; 高压 力波通过空气移动,他们身后留下低压区域。当这些压力低点 和高点——或波动——到达我们,他们在我们的耳朵振动接 收,我们听到时发出的震动声。 23 HMILYYLIMH 科技英语课件 Exercises 3.Unlike analog storage media such as magnetic tape and vinyl records, computers store audio information digitally as a series of zeros and ones. In digital storage, the original waveform is broken up into individual samples. This is know as digitizing or sampling the audio, and is sometimes called analog-to-digital conversion. The sampling rate defines how often a sample is taken. For example, CD-quality sound has 44.100 samples for each second of a waveform. 不像模拟存储媒体如磁带和唱片,计算机存储音频信息数字 化是一系列由0和1组成。在数字存储,原始波形分解成单独 的采样。众所周知作为数字化或抽样音频,有时被称为模拟数 字转换。采样率定义频率取样时。例如,cd品质的声音有每 秒钟44.100采样波形。 4.The higher the sampling rate, the closer the shape of the digital waveform will be to the original analog waveform. Low sampling rates limit the range of frequencies that can be recorded, which can result in a recording that poorly represents the original sound. 24 HMILYYLIMH 科技英语课件 Exercises 采样率越高，数字波形的形状越接近原来的模拟波形。低采 样率限制频率的记录范围，从而导致记录不充分，难以表示 原始的声音。 5.The sampling rate limit the frequency range of the audio file; to reproduce a given frequency, the sampling rate must be at least twice that frequency. For example, if the audio contains audible frequencies as high as 8,000 Hz, your need a sample rate of 16,000 samples per second to reproduce this audio accurately in digital form. This calculation comes from the Nyquist Theorem, and the highest frequency that can be reproduced by a given sample rate is known as the Nyquist Frequency. CDs have a sampling rate of 44,100 samples per second that allows samples up to 22,050 Hz, which is higher than the limit of human hearing, 20,000Hz. 25 HMILYYLIMH 科技英语课件 Exercises 采样率限制的音频文件的频率范围从而复制一个给定的频 率，采样率必须至少两倍的采样频率。例如,如果音频包含声 音频率高达8000赫兹, 你需要一个采样率为每秒16000个 样本复制本音频准确数字形式。这个计算来自于奈奎斯特定 理,和最高的频率可以复制出一个给定的采样率是众所周知 的奈奎斯特频率。cd有一个采样率的每秒44100个样本,允 许样本22050赫兹,这是高于人类听觉的极限,20000赫兹。 Uint 11 1.They are transmitting high-resolution full color images at the rate of 30 images per second, a transfer speed that enables full size full quality image viewing in real time. 他们在以30帧每秒的速率传输高分辨率全彩色图像，传输 速度能使全尺寸的完整的图像质量实时查看。 2.An image is a 2-dimensional distribution of energy, typically of visible electromagnetic radiation (light) but can also be of x-rays, ultraviolet, infrared or other radiation: electrons, acoustic waves or even nuclear particles. 26 HMILYYLIMH 科技英语课件 Exercises 图像是一个能量的二维分布，通常是可见的电磁辐射(光) 也可以是X射线，紫外线，红外线或其它辐射:电子，声波 甚至核粒子。 3.High resolution and full color are important for such examinations of standard prepared specimens, but resolution and colors may be reduced for freeze section service as these specimens are low in details and growth pattern is the prevailing feature analyzed. 高分辨率、全彩色是重要的对于这样的考试 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 制备试样, 但分辨率和颜色可降低标准冷冻切片服务，这些标本是低的 细节，增长模式是被分析过的流行特征。 4.Image discontinuities, on the other hand, usually correspond directly to object surface discontinuities (e.g., edges), since the other factors tend not to be discontinuous. Image discontinuities are generally consistent geometrically (i.e., in shape) even when not consistent photometrically. 27 HMILYYLIMH 科技英语课件 Exercises 图像的不连续性，另一方面，通常直接对应于物体表面的不 连续性(例如，边缘)，由于其他因素往往不间断。图像的 不连续性通常包括是几何图形(即，几何形)即使不一致的 光度测定。 5.In a television scanning generator using a pair of free-running relaxation oscillators, free-running frequencies of the oscillators are set slightly below the horizontal and vertical pulse rates, and the stripped pulses are used to trigger the oscillators prematurely and thus to synchronize them to the line and half-frame rates. 在采用一对自由张弛振荡器的电视扫描发生器中，振荡器的 自由频率被设置得略低于水平和垂直(扫描)频率，分离出 来的脉冲被用来提前触发振荡器从而使它们与行频和半帧 频(场频)同步。 6.The need for individual treatment of images makes strong demands on the methodology, but the fact that different features are important in different applications also opens new possibilities regarding data reduction. 28 HMILYYLIMH 科技英语课件 Exercises 用于图像处理的需要使得个体方法论的强烈需求，但事实 上，不同的功能在不同的应用程序也很重要，对于减少数据 打开新的可能性。 UNIT 12 1.Although some native speakers have problems in pronouncing some sounds they are perceived as native speakers based on their prosody and vocabulary. 尽管一些母语在发音上有问题，一些基于他们的韵律和词汇 的语言被视为母语。 2.A more adaptable technique is edge finding, which detects the regions of high rate of change of tone in an image, on the basis that these are likely to indicate edges of objects or ROI. 检测高清图像中的色调变化率最适合的技术是边缘检测，基 于此，这些可能表明物体或区域的边缘。 29 HMILYYLIMH 科技英语课件 Exercises 3.Many of these early systems had advantages that seemed exciting and intuitive when demonstrated with “toy” programs, but ran into difficult problems when attempts were made to extend them to more realistically-sized programs. 这些早期的系统优势，似乎令人兴奋的和直观的表现与“玩 具”的项目，但遇到困难的问题时，曾试图扩大他们更多的 实际程序的大小。。 4.Referring to the figure, we see that signal processing techniques are needed for preprocessing, pattern recognition techniques are needed for segmentation, feature extraction, and classification, and artificial intelligence techniques are needed for structure analysis, knowledge-acquisition and representation (world model), and control structure (interaction among the blocks). 参考图，我们看到信号处理技术是预处理所需要的，模式识 别技术是分割、特征提取以及分类所需要的，而人工智能技 术则是结构分析、知识获取及表示(世界模型)以及控制结 构(块间交互)所需要的。 30 HMILYYLIMH 科技英语课件 Exercises 5.The picture elements across a line are converted to the video signal and low-pass filtered with an electrical filter. This smoothing removes the discrete structure in the horizontal dimension. 沿着一条直线的图像像素被转换成视频信号，然后由一个电 子滤波器进行低通滤波。这一平滑处理可消除水平方向的离 散结构。 6.These products use commercially available speech toolkits, such as the IBM’s ViaVoice, Dragon’s Naturally Speaking, or L&H’s VoiceXpress, which were created for building voice-enabled applications for native speakers rather than for teaching foreigners. 这些产品使用市售的语音工具包，如IBM的一款声控软件， 现代月刊的自然演讲，或L&H的威狗论坛动漫游戏杂志，分 别建立语音创建启用的应用程序，这款程序为学习母语的人 而不是为了教外国人。 31 HMILYYLIMH 科技英语课件 Exercises 7.The three major forms of electronic documents mentioned above have a significant impact on the ways in which users select to manage the documents’ life cycle comprising creation or reception from an outside entity, processing, storage, retrieval and publishing. 电子文件上面提到的三种主要形式有关于如何在用户选择 的文件管理，文件管理的生命周期包括产生或接收从外部实 体，处理，存储，检索和发布。 8.Unfortunately in most applications scene shading is such that objects cannot be separated from background by any threshold, and even when an appropriate threshold value exists in principle it is notoriously difficult to find it automatically. 不幸的是，在大多数应用中场景阴影的物体不能被任何阈值 从背景分离，甚至当一个合适的阈值原则存在但是难以自动 找到它。 UNIT 13 32 HMILYYLIMH 科技英语课件 Exercises 1.A solid network design is crucial for maintaining a secure network. From perimeter firewalls to locking down endpoint devices and controlling user access, these resources help you build a secure layered network and identify vulnerabilities to prevent attacks. 一个坚实的网络设计是维护网络安全的关键。从防火墙来锁 定终端设备和用户访问控制，这些资源帮助你建立一个安全 的分层网络，找出漏洞以防止攻击。 2.Intrusion management is more than a tool or a person — it is also a process. These resources arm you with the knowledge you need to implement and maintain an intrusion management life cycle. 入侵管理不仅仅是一种工具或一个人，它也是一个过程。这 些资源为您提供你需要实现和维护一个入侵管理生命周期。 3.Several classes of human error have been identified and studied, and conditions that increase the likelihood of error can be specified in advance. 33 HMILYYLIMH 科技英语课件 Exercises 几类人类的错误已经被识别和研究和条件,增加错误的可能 性可以事先指定。 4.Similar attempts in other industries have failed because their reports were submitted through a chain of authority that included the person’s supervisor or plant management ( people who have biases to sanitize the report or to form negative judgments of the reporter. 在其他行业类似的尝试都失败了因为他们的报告是通过一 连串的权威，包括职员的主管或公司管理(一些对报告有偏见 或形成的不良报道的记者。 5.The preceding chapters have described how the automatic computer performs, but have not described how the automatic computer can be put to use to do data handling work to serve an organization, nor why such work is done in the way that it is. 前面的章节讲述了自动计算机是如何工作的，但没有讲述自 动计算机如何能用于数据处理工作以服务于一个机构，也没 有讲述这种工作为什么用这种方法实现。 34 HMILYYLIMH 科技英语课件 Exercises 6.The sources of the information are often reports in the media, reports that are incomplete, usually written before all relevant information is gathered, and subject to other sources of inaccuracies and biases. 这些资料的来源通常是媒体报道,由于报告不完整,通常在写 之前进行相关信息收集,并受其他来源的错误和偏见。 7.The threat is also placed in a theoretical political context by examining how it relates to paradigm- shifting technologies of the past, what its attractions and deterrents are, and how it would be analyzed and addressed within traditional realist/liberal national security schools. 威胁也看它涉及范式转换的过去的技术放在一个理论的政 治背景下，它的吸引力和威胁是什么，以及它将如何分析和 在传统的现实主义/自由国家安全学校解决。 35 HMILYYLIMH 科技英语课件 Exercises 8.While the subject of coding often carries with it an air of secrecy, a more important motive in many coding systems is the improved efficiency in conveying information. 如果说编码这一主题常带有一种秘密的色彩，那么许多编码 系统的一个更重要的目的则是为了提高信息传递的效率。 UNIT 14 1.Telemedicine has proven to be effective as a disaster response, a meaningful aid for the third world, care for the elderly and chronically ill in their homes, as well as a provider of health care to remote or isolated areas. 远程医疗系统已经被证明是个灾难响应有效的作为之一，一 个有意义的援助第三世界,照顾老年人和慢性病患者在他们 的家园,以及医疗保健提供商远程或偏远地区。 36 HMILYYLIMH 科技英语课件 Exercises 2.The continued surgical procedure is in certain cases dependent on this type of pathology service, and hospitals without access to frozen section service cannot treat such patients, but has to refer them to another hospital. 在某些情况下持续的外科手术是依赖于这种类型的病理服 务，医院没有进入冰冻切片服务时是不能治疗这类病人,但他 们求助于另一个医院。 3.The importance of early brain development in setting the foundations for language is apparent in babies younger than 6 months. 大脑的早期发展对于奠定语言基础的重要性在六个月以下 的婴儿中是显而易见的。 4.These are typical cases where use of telediagnostics would strongly benefit the patients, and at the same time reduce costs and free medical resources. 37 HMILYYLIMH 科技英语课件 Exercises 这些都是典型的情况下，使用电子诊断获益的患者，同时降 低成本和免费的医疗资源。 5.Whether telemedicine will be a general success will to a large extent depend on whether or not one manages to meet the real challenge ( to make such systems work as close to the standard methods as possible, employing telecommunication systems available on a general basis, and with acceptable quality and costs。 远程医疗能否取得一般性的成功，将在很大程度上取决于是 否能够满足真正的挑战(使这样的系统接近尽可能的标准方 法，在可用的通用原则以及可接受的质量和成本上尽可能采 用电信系统。 6.A telediagnostic approach would require approximately 20 randomly selected images with standard resolution in black and white (512(512 pixels with 8 bit resolution per pixel) which can be transferred over a standard ISDN channel within less than six minutes. 38 HMILYYLIMH 科技英语课件 Exercises 一种电子诊断方法将需要约20个随机选择的图像与标准分 辨率在黑色和白色(512*512像素分表率在8位/像素)可以 到一个标准的ISDN通道在不到六分钟。 Unit 15 Because digital image processing does encompass such a wide variety of techniques and mathematical tools, each application involves a sequence of processing steps. These steps are modules that can be arranged in an enormous number of different sequences, and each module generally admits the specification of parameter values that further expand the range of possible manipulation schemes to achieve the desired results. The major advantages of digital images as compared with analog (i.e. film) images are the quality of the data and the accessibility of that data to computer manipulation. The quality advantage is really an aggregate of two advantages: 39 HMILYYLIMH 科技英语课件 Exercises Dynamic range: up to 128 or more gray levels can be present on digital images whereas only 15(30 discernible on film products. Reproducibility: a copy of a copy of a copy of a digital image contains exactly the same data as the original, whereas a forth-generation photographic product is substantially degraded in comparison with the original. Although these are advantages, the compelling advantage for the applications community derives from the accessibility of the data to computer manipulation. To generate a general-purpose film product is essentially to choose a compromise among competing requirements from agronomists, hydrologists, foresters, geologists, urban planners, and other user groups; it is not optimized for any one. Digital images lend themselves to custom tailoring by the user for his or her application in a way that film products cannot. 40 HMILYYLIMH 科技英语课件 Exercises 数字图像处理包括了多种多样的技术和数学工具，每一项应用都涉及到一系列的处理步骤。这些步骤是以大量不同次序排列的各种模块，每一模块通常容许一些参数值的技术指标，从而进一步扩大了为获得预期结果而可能采取的处理方案的选择范围。与模拟图像(即胶片)相比，数字图像的主要优点在于数据的质量和数据可供计算机进行处理这两方面。 质量方面的优越性实际上是以下两种优越性的综合:动态范围:数字图像可表现128级或更多的灰度，而胶片产品只能分辨15至30级; 重现性:一幅数字图像多次复制后仍与原件包含完全相同的信息，而一幅第四代的照片与原件相比却大大地退化(损伤)了。 虽然这些是优点,引人注目的优势应用社区来源于计算机处理的数据的可访问性。生成一个通用的电影的产品基本上是妥协在选择相互竞争的要求，从农艺学家，水文学家，地质学家，林业，城市规划者，和其他用户组;它不是优于任何一个。数字图像自身能够由用户定制裁缝为他或她的应用程序的方式,但是电影产品不能。 41 HMILYYLIMH 科技英语课件 Exercises Unit 16 1.Another group of commercial visual programming environments (VPEs) are the Computer-Aided Software Engineering (CASE) tools that support visual specification (for example, using diagrams) of relationships among program modules in automatic code generation of composition code. 另一组商业可视化编程环境(VPEs)是计算机辅助软件工程 (CASE)工具,支持视觉 规范 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 (例如,使用图)的程序模块之间的 关系在自动代码生成的代码组成。 2.In recent years, there has been a tremendous increase in the use of digital computers and special-purpose digital circuitry for performing varied signal processing functions that were originally achieved with analog equipment. 42 HMILYYLIMH 科技英语课件 Exercises 近年来为实现各种信号处理功能，数字计算机和专用数字电 路的使用有了巨大的增长，这些处理功能原先都是用模拟设 备实现的。 3.In the beginning, computers were used to process only numerical information, but majority of our information is non-numerical in nature and very little is known about its description and processing. 一开始计算机只是被用来处理数值信息，而我们的大多 数信息都是非数值性质的，而且人们对这些信息的描述和处 理所知甚少。 4.In this approach, straightforward visual techniques were widely incorporated into programming environments that support textual programming languages, to replace cumbersome textual specification of GUI layout, to support electronic forms of software engineering diagrams for creating and/or visualizing relationships among data structures, and to visually combine textually-programmed units to build new programs. 43 HMILYYLIMH 科技英语课件 Exercises 在这种方法中，简单的视觉技术被广泛纳入的编程环境，支 持文本的编程语言，代替繁琐的GUI布局文本规范，支持电 子形式的软件工程图创建和/或可视化数据结构之间的关系, 以及视觉结合文本编程单元来构建新项目。。 5.The ACM could take the lead in establishing some positive, constructive actions to elevate the human side of computing to a level of concern and respectability equal to that of the physical and symbolic side. ACM可以率先建立了一些积极的，建设性的行动来提高人 的计算到关注和尊重平等的物理和象征性的方面的一个程 度。 6.Until now the human race has undergone two great waves of change, each one largely obliterating earlier cultures or civilizations and replacing them with ways of life inconceivable to those who came before. 44 HMILYYLIMH 科技英语课件 Exercises 直到现在,人类经历了两次大的变革浪潮,每一种文化或文明 很大程度上清除的早些时候,代之以生活方式不可想象的那 些之前。 Unit 17 1.For the first time ever the landscape is changing, as high volume personal computer multimedia applications proliferate. First affected were monitors, which for some time have offered higher-than-broadcast speed and resolution. One can expect cameras to follow, with high-speed, high-resolution devices driven by consumer digital still camera technology and lower-resolution, ultra low cost units driven by entertainment, internet conferencing, and perceptual user interface applications. 随着大量个人计算机多媒体应用的急剧增加，情况首次发生 了变化。最早受到影响的是显示器，相当长时间以来它已经 能够提供比广播级更高的分辨率和速度。人们可期待照相机 /摄像机也随之跟上，包括由民用数字照相机所推动的高速 度、高分辨率器件，娱乐业、互联网远程会议和用户视觉界 面应用所推动的低分辨率和极低价格的设备。 45 HMILYYLIMH 科技英语课件 Exercises 2.If you already have the fastest CPU in a particular family and still want more performance, then it may be more cost-effective to add system RAM or cache RAM than to put in a processor from a different family. Adding system memory can bring significant performance increases at a relatively low cost, assuming you configure the memory correctly. In addition to added cache and system RAM, a faster and larger hard drive can save you time when running applications dependent on heavy drive access and data throughput. Adding a graphics accelerator card can help, too, especially if you are looking for a way to stay awake while your system redraws images. 如果你已经有了某一系列中最快的CPU而还想要更多的性 能，那么增加系统RAM或高速缓存RAM也许比插入一枚另 一系列的处理器更合算。特别是如果你是一名Windows用 户，假设你正确地配置内存，则增加系统内存可以较低的代 价带来可观的性能提高。除了增加高速缓存或系统RAM， 一个更快和更大的硬盘可在运行依赖于大量读写硬盘和有 大量数据吞吐时节省你的时间。增加一个图形加速器也是有 益的，如果你使用Windows，而且发现你在寻找某种途径使 你在系统重显图象时能保持“清醒”，则尤其是如此。 46 HMILYYLIMH 科技英语课件 Exercises 3.In university environments, MATLAB has become the standard instructional tool for introductory courses in applied linear algebra, as well as advanced courses in other areas. In industrial settings, MATLAB is used for research and to solve practical engineering and mathematical problems. Typical uses include general purpose numerical computation, algorithm prototyping, and special purpose problem solving with matrix formulations that arise in disciplines such as automatic control theory, statistics, and digital signal processing (time-series analysis). 在大学环境里，它已成为应用线性代数导论以及其他领域中 许多高级课程的标准教学工具。在工业界，MATLAB被用于 研究和解决实际的工程和数学问题。典型的应用包括通用数 值计算、算法原型测试以及使用矩阵公式的专门问题的解 决，这些问题是在自动控制理论、统计、数字信号处理(时 间序列分析)等学科中提出来的。 47 HMILYYLIMH 科技英语课件 Exercises 4.Multimedia is a generic term for “multimedia computing” or “interactive multimedia”. The computer and software are used to control and navigate through the communications links, not only one at the time, but several simultaneously. Computer systems have been most developed in using vision and hearing to interface between the digital and analogue worlds, e.g., still and moving images, text and graphics use the visual senses, and audio uses hearing. Multimedia is defined as visual, audio and textual information which can be presented, separately or simultaneously, to convey and present information interactively to users. It is technically easy to digitize the analogue forms of these common media and handled by computers now widely available and inexpensive to be accessible to most users. 48 HMILYYLIMH 科技英语课件 Exercises 多媒体是表示“多媒体计算”或“交互式多媒体”的一般术语。计算机和软件被用于控制并通过不止一条通信链接同时进行浏览。在利用视觉和听觉在数字和模拟世界之间进行交互方面，计算机系统已得到极大的发展，例如对静止和活动图像、文本和图形使用视觉，对音频使用听觉。多媒体被定义为可以分别或同时展现的视频、音频、文本信息，用以交互式地将信息传递和展示给用户。技术上很容易将这些普通媒体的模拟形式用计算机实现数字化并加以处理，计算机现在已十分普遍，其价格便宜，大多数用户都能使用。 49 HMILYYLIMH 科技英语课件 Exercises 5.The essential capability of any multimedia computer system is the ability to convert the analogue signal to a digital format and to compress this information using standard algorithms. The power of the CPU will determine whether this process can be carried out in real-time or whether it has to be done off-line. Originally this power only existed in UNIX systems, but more recently it has become available in PCs and Macintosh. The compression process is necessary otherwise the quantity of data to be stored and transmitted would be excessive. Most PCs have until recently depended upon hardware encoding/decoding systems, but the speed of current processors is such that software compression systems have been developed. The advantage of the software systems is that the compatibility and interoperability issues can be handled more easily, and the cost of the equipment is not raised by the need to purchase expensive hardware devices. 50 HMILYYLIMH 科技英语课件 Exercises 任何多媒体计算机的基本功能是将模拟信号转换成数字格式，并用标准算法将此信息压缩的能力。CPU处理能力将决定是否能实时完成此过程还是必须离线执行。原先只有UNIX系统才有这种实时能力，但近年来PC和Macintosh也能胜任(有这种能力)了。压缩是必须的，否则要存储和传送的数据量太大。直到不久前大多数PC还依赖硬件编解码系统，而目前的处理器速度已使软件编解码系统的开发成为可能。软件系统的优点在于可更方便地处理兼容性和协同工作问题，而且不会因购置昂贵的硬件而提高设备成本。 UNIT18 1.The Third Wave We are now at the start of the so-called third wave of civilization development. 51 HMILYYLIMH 科技英语课件 Exercises The first-wave civilization lasted until 1700 and was based on agriculture. Majority of the population worked on the land or were employed in activities associated with food production. Only a small minority belonged to a merchant class who were associated with trade and manufacturing. The first wave society was characterized by low mobility, slow rates of change and local organizations. 第三波 现在，我们处于文明发展的所谓的第三波的开端。 第一波文明延续至公元前1700年，它是以农业为基础。那 时，大多数人在田间工作或从事与食品生产有关的活动。只 有一小部分人属于与贸易和制造业有关的商人阶级。第一波 社会的特点具有低的移动性，变化的速度缓慢和地方组织。 52 HMILYYLIMH 科技英语课件 Exercises 2.The second wave includes the industrial revolution and the period up to the recent time. Most of the people were no longer required to work on the land for food production. Industry grew and became the largest employer; cities expanded rapidly and the need for information and communication increased dramatically. Consumption of goods became separated from the production of goods and society became polarized into the two groups of producer and consumer. 第二波包括从工业革命时期到近代。大部分的人不再需要为 了粮食生产而工作田间。城市迅速的扩张，信息和通信的需 求急剧增加，工业的增长，成为最大的雇主。消费品变从商 品和社会的生产中分离出来，并分化为两组，即生产者和消 费者。 53 HMILYYLIMH 科技英语课件 Exercises 3.There are many factors causing the second wave of industrial development to come to an end, among which are two major events: the end to an apparently unlimited supply of cheap energy and the increasing concern over the effects of industrial exploitation and environmental pollution. However, perhaps the most important factor is the development of modern electronics, computer technology, and telecommunications. 引起工业发展的第二波结束的因素很多，其中主要有两个事 件:很明显，应结束无限制的廉价的能源供应，以及工业开 发和环境污染的影响也增加人们的担忧。然而，或许这最重 要的因素是由于现代电子技术、计算机技术和电信的发展。 54 HMILYYLIMH 科技英语课件 Exercises 4.The third-wave development began in the late 1950s. It was characterized by the development of new industries such as computers and data processing, aerospace, semiconductors and advanced communications. These new industries are markedly different from their predecessors in that they avoid the use of high-energy inputs and pollution, and tend to employ highly skilled workforces. It is expected that the third wave will bring the world to an unprecedented bright future. 第三波的发展始于20世纪50年代末。它的特点是新的产业， 如计算机和数据处理、航天技术、半导体和先进的通信的发 展。这些新产业明显不同于他们的前者，他们避免高能量输 入和污染的使用，并倾向于雇佣高技能劳动力。预计第三波 会把世界带到前所未有的光明的未来。 5.Moore’s Law 55 HMILYYLIMH 科技英语课件 Exercises Moore, one of the founders of Intel, observed in an article in the April 19, 1965 issue of Electronics magazine that innovations in technology would allow a doubling of the number of transistors in a given space every year (in an update article in 1975, Moore adjusted the rate to every two years to account for the growing complexity of chips), and that the speed of those transistors would increase. What is less well-known is that Moore also stated that manufacturing costs would dramatically drop as the technology advanced. 摩尔定律 摩尔是英特尔的创始人之一，他在1965年4月19日的电子 杂志观察到一篇文章，关于技术创新方面将允许在一个给定 的空间使每一年的晶体管数量增加了一倍(在1975年更新 的文章中，由于日益复杂的芯片的原因，摩尔调整了速率改 为每两年)，并且对于那些晶体管的速度还会增加。少为人 知的是，摩尔还表示，由于技术先进，晶体管生产成本仍将 大幅下降。 56 HMILYYLIMH 科技英语课件 Exercises 6.Moore’s prediction, now popularly known as Moore’s Law, had some startling implications, predicting that computing technology would increase in value at the same time it would actually decrease in cost. This was an unusual idea at the time since, in a typical industry, building a faster, better widget with twice the functionality also usually means doubling the widget’s cost. However, in the case of solid-state electronics, the opposite is true: Each time transistor size shrinks, integrated circuits (ICs) become cheaper and perform better. 摩尔的预测，现在被称为摩尔定律，它具有惊人的影响，他 预测计算机技术在增加价值的同时，实际上也会降低成本。 自当时以来，在这个典型的产业，这是一个不寻常的思想， 在构建一个更快的和具有两倍的功能更好的部件也通常意 味着加倍的部件的成本。然而，在固态电子学的情况下，事 实恰恰相反的:每次晶体管的尺寸和集成电路(IC)缩小， 它们都变得更加便宜和具有更好的性能。 57 HMILYYLIMH 科技英语课件 Exercises 7.In 1965, a single transistor cost more than a dollar. By 1975, the cost of a transistor had dropped to less than a penny, while transistor size allowed for almost 100,000 transistors on a single die. From 1979 to 1989, to 1999, processor performance went from about 1.5 million instructions per second (MIPS), to almost 50 MIPS on the i486?, to over 1,000 MIPS on the Intel? Pentium? III. Today’s Intel? processors, some topping out at well above 1 billion transistors, run at 3.2 GHz and higher, deliver over 10,000 MIPS, and can be manufactured in high volumes with transistors that cost less than 1/10,000th of a cent. 在20世纪70年代，一个单晶体管的成本超过一美元。到 1975年，一个晶体管的成本已经下降到不到一分钱，而晶 体管尺寸允许在一个单模有近100000晶体管。从1979年 到1989年，再到1999年，在i486处理器上，处理器的性 能就从约每秒150万条指令(每秒百万条指令)，到近每秒5 千万条指令，再到在英特尔奔腾III处理器运行超过每秒10 亿条指令。今天的英特尔处理器，有些超出了10亿以上的 晶体管，其运行在3.2 GHz或高于3.2 GHz，其传送指令超 过每秒10亿条，在制造大量的晶体管，成本却不到一美分 万分之一。 58 HMILYYLIMH 科技英语课件 Exercises 8.Intel’s innovations in shrinking transistor size while dramatically improving performance mean that advanced technology can be delivered for almost every industry, from computing and communications, to agriculture, mechanics, and medicine. Today’s microprocessors power the economy, fuel the growth of the Internet, and run everything from toys to traffic lights. That in turn has touched billions of lives, and transformed the world and the human experience. 英特尔的创新缩小晶体管的尺寸，同时极大地提高了性能， 它意味着先进的技术可以提供几乎所有的行业使用，从计算 和通讯，到农业、机械和医药。今天的微处理器激励着经济， 推动互联网的发展，并运行一切从玩具到交通灯。反过来那 些处理器也触摸着亿万人的生活，并改变了世界和人类的体 验。 Unit 19 59 HMILYYLIMH 科技英语课件 Exercises 1.Artificial Intelligence is a branch of science that helps machines find solutions to complex problems in a human-like fashion. This generally involves borrowing characteristics from human intelligence, and applying them as algorithms in a computer friendly way. Computers are fundamentally well suited to performing mechanical computations using fixed rules. This allows machines to perform simple monotonous tasks efficiently and reliably, which humans are not suited to. Unlike humans, however, computers have trouble in understanding specific situations, and adapting to new situations. Artificial Intelligence aims to improve machine behavior in tackling such complex tasks. Humans have an interesting approach to problem-solving, based on abstract thought, high-level reasoning and pattern recognition. Artificial Intelligence can help us understand this process by recreating it, then potentially enabling us to enhance it beyond our current capabilities. 60 HMILYYLIMH 科技英语课件 Exercises 人工智能是一个科学分支，它可以帮助机器找到像人那样解决复杂问题的解。这通常包括从人的智能中借用一些特征，应用这些特征开发出便于计算机实现的算法。计算机原则上适合于按照固定的编程规则进行机械性的计算，这使得机器能够有效而可靠地执行简单单调的任务，这正是人所不擅长的。然而不同于人，计算机难以理解特定的情形，适应的新情况。人工智能的目标就是改进机器的性能以对付这种复杂的任务。人类具有一种解决问题的有趣能力，这种能力是基于抽象思维、高级推理和模式识别的。人工智能可以通过重建这一过程来帮助我们理解它，进而使我们的能力有可能超越当前的水平。 61 HMILYYLIMH 科技英语课件 Exercises 2.An expert system is a computer application that performs a task that would otherwise be performed by a human expert. For example, there are expert systems that can diagnose human illnesses, make financial forecasts, and schedule routes for delivery vehicles. Some expert systems are designed to take the place of human experts, while others are designed to aid them. Expert systems are part of a general category of computer applications known as artificial intelligence. To design an expert system, one needs a knowledge engineer, an individual who studies how human experts make decisions and translates the rules into terms that a computer can understand. 专家系统是一个计算机执行任务的应用程序，否则将被人类 专家执行。例如，有的专家系统，可以诊断人的疾病，可以 进行财务预测，还可以安排运载工具的路线。有些专家系统 的设计，而另一些设计，以帮助他们来代替人类专家。专家 系统是被称为人工智能计算机应用的总体的一部分。要设计 一个专家系统，需要知识工程师——一个研究人类专家是如 何做出决定并转化成一台计算机可以理解的条款规则的个 体。 62 HMILYYLIMH 科技英语课件 Exercises 3.The history of AI, like that of any other science, is one that is filled with surprises, false events, and occasional successes. Probably the most important lesson to date from research in AI is that problems that were thought to be easy (i.e., the ones that a two-year-old can handle effortlessly ( e.g., recognizing faces) are extremely difficult to mechanize (given the current state of art). Problems that were thought to be hard (i.e., the ones that require years of formal training ( e.g., proving theorems in mathematics) are embarrassingly easy to mechanize. Is it really the case that cognition can be fully understood in terms of computation? Are cold logic and rationality sufficient for intelligence? Are they necessary? Do we need anything else? If so, what? AI research meshes with some of the most exciting philosophical questions. It also offers tremendous scientific and technological challenges. 63 HMILYYLIMH 科技英语课件 Exercises 人工智能的历史，就像任何其他的科学，是一个充满了惊喜，虚假事件，以及偶尔的成功。也许最重要的教训是，在人工智能的研究中，迄今为止被认为是容易的(即，一个两三岁的孩子可以毫不费力地处理,例如，面部识别)问题是非常难以实现机械化(鉴于目前艺术状态)。被认为很麻烦的问题是，戏剧性地(即，那些需要多年的正规培训,例如，证明数学定理)易于实现机械化。认知真的可以被充分理解和计算吗,冷逻辑和理性，足够的智慧吗,他们有必要吗,我们需要什么吗,如果是这样，是什么, 人工智能研究与一些最令人兴奋的哲学问题交织在一起。它还提供了巨大的科学和技术挑战。 Unit 20 64 HMILYYLIMH 科技英语课件 Exercises 1.At level 4, the system responds to program edits as in level 3, and to other events as well such as system clock ticks and mouse clicks over time, ensuring that all data on display accurately reflects the current state of the system as computations continue to evolve. 在第4级中系统响应程序编辑就像在第3级一样，和其他事 件，如系统时钟的滴答声和鼠标点击，随着时间的推移，确 保所有显示的数据，当计算持续进行的时候，准确地反映了 当前的系统状态，。 2.For important issues, several different representations are often provided to let students think about the same problem or view the same phenomenon from different perspectives. In this way the impression of the learner is effectively enhanced and the teaching results improved. 对于重要的问题，有几个不同的陈述，往往让学生思考同样 的问题，或从不同的角度看待同样的现象。这样学习者的印 象就能有效地提高，改进教学效果。 65 HMILYYLIMH 科技英语课件 Exercises 3.His invention allowed for the mass distribution of information, permitting common men to possess otherwise scarce texts like the Bible。 他的发明使得信息成批分发，允许普通人拥有其他稀缺的文 本，比如“圣经”。 4.It is rare that the optimization will be achieved in only one step, and usually many iterations around the analysis-error-adjustment loop will be required for obtaining a satisfactory result. 只经过一步就达到优化的情况是罕见的，为了得到满意的结 果通常要围绕“分析,误差,调节”的循环进行多次迭代。 5.To take the argument even further, author Kevin Kelly argues that cultural advances, like the printing press “prepared a possibility space that allowed human minds and bodies to shift so that some of what it once did biologically would afterwards be done culturally.” 66 HMILYYLIMH 科技英语课件 Exercises 为了进一步采取论点，作者凯文?凯利认为，文化的进步， 像印钞机“准备一个可能性的空间，使人类的思想和身体移 位，使得这一次也没有什么生物上的变化，在之后有一些文 化上的变化。” 6.Our reliance on computer technology and our quick transition into a knowledge-based economy have left us vulnerable to attack, and that vulnerability creates difficult political dilemmas that must be dealt with should we wish to continue following the currents of the Third Wave. 我们对计算机技术的依赖和我们要成为一个以知识为基础 的经济体系的快速转型已经让我们非常容易受到攻击，该漏 洞制造的了必须要处理的政治困境，我们希望继续按照第三 波浪潮。 7.Several of these structures may be deemed as too complex to implement in practice; nevertheless, their performances serve as benchmarks against which many suboptimum but practical structures will be compared later. 67 HMILYYLIMH 科技英语课件 Exercises 这几个结构可以被视为过于复杂，以至于难以在实践中实 现;然而，与许多次优但实际结构将被进行比较后的相比， 他们的表现可以当作基准。 8.Similarities to historical technological developments need to be explored and contrasted with new technology to develop hypotheses regarding the future strategic impacts that these new technologies will have. 与历史的技术发展相似点需要被探索，基于未来的战略影 响，这些新技术将会和新技术发展的假说进行对比。 68 HMILYYLIMH