资源预览内容
第1页 / 共14页
第2页 / 共14页
第3页 / 共14页
第4页 / 共14页
第5页 / 共14页
第6页 / 共14页
第7页 / 共14页
第8页 / 共14页
第9页 / 共14页
第10页 / 共14页
亲,该文档总共14页,到这儿已超出免费预览范围,如果喜欢就下载吧!
资源描述
第一章Electronic amplifiers are used mainly to increase the voltage , current ,or power of a signal . 电子放大器主要是用来增强电压,电流或信号(信号功率)的强度A linear amplifier provides signal amplification with little or no distortion , so that the output is proportional to the input .线性的放大器能几乎无失真地放大信号,从而使输出与输入相称 A nonlinear amplifier may produce a considerable change in the waveform of the signal .非线性放大器在信号的波形方面会产生相当大的变动 Linear amplifiers are used for audio and video signals , whereas nonlinear amplifier find use in oscillators , power electronics , modulators , mixers , logic circuits , and other applications where an amplitude cutoff is desired . 线性放大器用于音频信号,而非线性放大器用于振荡器,电力电子学,调节器,混音器,逻辑电路以及其他的要求振幅中断的器材Although vacuum tubes played a major role in amplifiers in the past , today either discrete transistor circuits or integrated circuits are mostly used .尽管真空管在过去的放大器中充当了主要的角色,而如今最常用的是离散的晶体管电路或集成电路第二章Configurable computing is still an extremely young field .可配置计算仍然是极年轻的领域 Although Gerald Estrin of the University of California at Los Angeles proposed configurable computing in the late 1960s , the first demonstrations did not occur until a few years ago , and current FPGAs ,with up to 100,000 logic elements , still do not come close to exploiting the full possibilities of the technique . 虽然可配置计算是由洛杉矶加州大学的杰拉尔德艾斯特林在1960年代末期提出的,但是在几年前才首次展示给世人,甚至,含有十万个逻辑元件的电流FPGA(现场可编程门阵列)仍未能开发出其技术的全部潜力Future FPGAs will be much larger , as with many other integrated circuits , the number of elements on a single FPGA has doubled roughly every 18 months . 正如许多其他的集成电路一样,未来的FPGA会(比目前的)大的多,单一的FPGA中的元件的数量约每隔一年半就会翻倍。 Before the decade is out , we expect to see FPGAs that have a million logic elements .十年之后,我们期盼着会出现含有一百万个逻辑元件的FPGA Such chips will have much broader application , including highly complex communications and signal-processing algorithms .这些芯片应用范围更广,包括应用于高度合成的通讯系统和信号加工算法。第三章Variable-length instructions are more difficult for a chip to process , though , and the longer CISC instructions are especially complex . 可变长度指令使芯片更难处理,而较长的CISC(复杂指令集计算)指令特别复杂。Nonetheless , to maintain software compatibility , modern chips such as Intels Pentium III and Advanced Micro Devices Inc.s Athlon must still work with all troublesome CISC instructions that were designed in the 1980s , even though their original advantage-memory conservation-isnt as important .尽管如此,为了维持软件兼容性,诸如英特尔奔腾3和AMD公司(高级微设备公司)的速龙这样的现代芯片,虽然它们最初的优势存储保护不是那么重要,但都还是用1980年代设计的令人费劲的CISC指令处理。第四章The TCP/IP (Transmission Control Protocol/Internet Protocol) protocol suite supports the Internet , the single largest computer network in the world .TCP/IP(传输控制协议/互联网协议)支持全世界单个最大计算机网络,也即是互联网。 The Internet is not a single network .Rather ,it is an internet consisting of many smaller networks .互联网不是单个的网络,而是由许许多多更小的网络组成的。The Internet (note the definite article and the capital “I”) is unique for it contains more than 11000 networks and a million hosts .互联网(注意定冠词和大写的“I”)是唯一的,因为它包括了11000多个网络和一百万个主机。 It is a multiprotocol internet , since protocol suites other than TCP/IP also are used .协议套房除了TCP / IP也使用,所以这是个多重协议的因特网 However , the TCP/IP protocol is by far the most widely used .但在目前最普遍使用的还是TCP/IP协议。第五章A number of biometric characteristics exist and are in use in various applications (see Figure 1) .许多的生物计量特征存在和正使用于各种各样的应用程序中。(详见图形1) Each biometric has its strengths and weaknesses , and the choice depends on the application .每个生物计量都有其各自的优劣势,这选择取决于它们的应用程序 No single biometric is expected to effectively meet the requirements of all the applications . 并非单个生物计量都能如愿且有效地满足所有应用程序的要求的。In other words , no biometric is “optimal” .换言之,没有生物计量是最理想的。 The match between a specific biometric and an application is determined depending upon the operational mode of the application and the properties of the biometric characteristic .决定某个特定的生物计量和某个应用程序间是否匹配取决于应用程序的运作模式和生物计量的性能。A brief introduction of the commonly used biometrics is given below .如下会给出常用生物统计学的简单介绍。第六章Ideally , humans can hear sounds that fall within a frequency range of 20 HZ to 20 kHZ . 理想上,人们能听到频率在20到20000赫兹之内的声音。 As we age , our ability to hear high-frequency sounds diminishes , so its fair to say that adults can hear sounds as high as 10 kHZ to 15 kHZ .当我们变老时,我们听高频声音的能力相应减弱,因此,说成人能听到10到15000赫兹间的声音是一点也不夸张的。 You might think that since we can only hear frequencies up to a certain frequency , a 22 kHZ sampling rate would be more than enough . The truth is , unfortunately , a little more complicated .你可能会认为既然我们只能听到某一定频率到某一特定频率(间的声音),那么22000赫兹的采样率是绰绰有余的。很遗憾,事实上是更复杂些。第七章The face retrieval problem , known as face detection , can be defined as follows :人脸检索问题也即人们常说的人脸检测可定义如下: given an arbitrary black and white , still image , find the location and size of every human face it contains . 考虑到这其中任意的黑白片静态影像,以及要寻找每张脸的拍摄场地和它们的尺寸大小。There are many applications in which human face detection plays a very important role :(就需要)很多程序在人脸检测方面发挥重要作用。 it represents the first step in a fully automat
网站客服QQ:2055934822
金锄头文库版权所有
经营许可证:蜀ICP备13022795号 | 川公网安备 51140202000112号