PickHDB3 yards ( third-order high-density dual polarity yards) is the most commonly used in modern transmission system is one of the MaXing, is widely This study is based on the main content of the HDB3 yards encoder CPLD device First of HDB3 yards and CPLD application and research status were introduced, This paper used to MaxPlusII and VHDL language software, Finally HDB3 yards are analyzed in detail by VHDL language encoding principle and realization Based on the principle of coding HDB3 yards, the paper analyzes the design scheme of HDB3 code design mainly divided into three coder realized module ( insert V module, modeling and realize the modeling and realization, B module modeling and realize polarity transform module) After completion, the software design in the simulation, MaxPlus2 test results and the design idea of early, so right, completed based on simulation HDB3 code design of CPLD Keywords: HDB3, VHDL, Polarity transformation
HDB3 yards ( third-order high-density dual polarity yards) is the most commonly used in modern transmission system is one of the MaXing, is widely This study is based on the main content of the HDB3 yards encoder CPLD device First of HDB3 yards and CPLD application and research status were introduced, This paper used to MaxPlusII and VHDL language software, Finally HDB3 yards are analyzed in detail by VHDL language encoding principle and realization Based on the principle of coding HDB3 yards, the paper analyzes the design scheme of HDB3 code design mainly divided into three coder realized module ( insert V module, modeling and realize the modeling and realization, B module modeling and realize polarity transform module) After completion, the software design in the simulation, MaxPlus2 test results and the design idea of early, so right, completed based on simulation HDB3 code design of CPLD
summary"with computer network technology matures, computer networking applications has become an inevitable trend in the development of the Network technology to speed the development direction, broadband network has become an inevitable The computer network communication technology from the 1960s, has been greatly since birth, especially the development since 1990s have developed As is known to all, the computer network communication technology is to unexpected speed rapid development, network communication technology, the Internet also permeates gradually to people living and working in every The information superhighway has direct extends to the people, the desktop, alwin in its future study TuoFuLe transfer of power masterpiece, "said: in ancient times, the strength of a country's military strength, main farmar 200 years ago, humans into industrial society, the industrial productivity, and Jordan farmar into since the 1970s, a country with knowledge of the network access storage capacity has become an important measure of its overall The Clinton 11993 government announced in September, the national information highway NLL (1994), National1Information1Intrasture - global information highway After this, the world also has its own information highway planning, Each system in our country, and various business unit interior also raised one Internet construction Along with the computer network technology matures, computer networking applications has become an inevitable trend in the development of the Our government has recently proposed 12,000 years in the construction of the electronic government, the government plans to cross-century some office affairs in the Internet, improving people's government work, understand the supervision, People can inquire on the net himself about the state policies, laws and regulations, enhance the consciousness of the masses participating Although the traditional 10MBPS Ethernet satisfy the demand of users at many network to a certain extent, to solve the network information resources sharing and However, with the rapid increase of the CPU performance, workstations, user application software functions of information, network transmission of complexity and information, plus the sharp rise in the rapid development of multimedia technology in network applications, 10MBPS transmission bandwidth, already can't satisfy the development of computer technology, network transmission requirements to high-speed broadband network technology has become an inevitable trend in the development of The computer network in every field application, computer network communication technology, while the but for thirty years, but with human civilization has never existed before the power and speed in this world of rapid popularization, development, It is human civilization and any a kind of totem, machine, intercourse and survival of different rules is enormous, she seems to be working with echoes in the "information" fiber that create the future of the dominant force in The computer network will be broken, and age, economic region of cultural consumption ability, make the future society into a harmonious and unified show circle, human society will eventually into equal share of democracy, open Along with the computer network communication technology, the computer network, the development of social life in the fields of application, get more information becomes an indispensable part of the 摘要】随着计算机网络技术的日趋成熟，计算机的网络化应用已成为计算机发展的必然趋势。网络技术向高速，宽带方向发展已成为网络发展的必然趋势。 计算机网络通讯技术从20世纪60年代诞生至今，得到了极大的发展，尤其是进入20世纪90年代以来得到了飞速的发展。众所周知，计算机网络通讯技术正在以人们意想不到的速度迅速发展着，网络通讯技术日新月异，Internet也逐渐渗透到人们生活和工作的每一个角落。信息高速公路已经直接延伸到了人们的桌面上，阿尔文·托夫勒在其未来学名著《权力的转移》中说：在古代，衡量一个国家国力的主要砝码是军事实力，200年前，人类进入工业社会以后，这一砝码变为工业生产力，而从本世纪70年代开始，一个国家拥有的存储与访问知识的网络能力已开始成为衡量其综合国力的重要指标。美国克林顿政府11993年9月公布了国家信息高速公路计划。（NLL-National1Information1Intrasture），1994年提出全球信息高速公路计划。在此之后，世界各国也先后推出了自己的信息高速公路计划；在我国各系统，各企事业单位内部也掀起了一股Internet建设的热潮。随着计算机网络技术的日趋成熟，计算机的网络化应用已成为计算机发展的必然趋势。我国政府最近又提出了在12000年建设网上电子政府的跨世纪计划，政府的一些办公事务在网上进行，提高人民群众对政府工作的监督，了解；群众可以在网上查询自己关心的国家的政策，法律法规，增强人民群众参政议政的意识。虽然传统的10MBPS以太网满足了当时许多用户的网络需求，一定程度上解决了网络资源信息和外围的共享问题。但是，随着CPU性能的迅速提高，工作站数量的增加，用户应用软件功能的不断增强，网络传输信息的日益复杂化和信息量的急剧提高，再加上迅速发展起来的多媒体技术在网络上的应用，10MBPS的传输带宽，已远远不能满足日益发展的计算机技术对网络的传输要求，网络技术向高速，宽带方向发展已成为网络发展的必然趋势。计算机网络在社会各个领域中的应用，计算机网络通讯技术虽然从诞生至今不过三十几年的时间，却以人类文明史上从未存在过的力量和速度在这世界得到迅速的普及，发展；它与人类文明史上的任何一种图腾，机器，交往方式甚至生存规则都有着巨大的不同——她似乎正用激荡在光纤中的“信息比特”预示出创造未来社会进步的主导力量。计算机网络将彻底打破地域，年龄，经济能力等对文化消费的禁锢，使未来社会展现成一个和谐统一的文化圈，人类社会将最终进入平等开放，共享民主的时代。随着计算机网络通讯技术的日益发展，计算机网络在社会生活中的各个领域得到越来越多的应用，成为信息经济时代不可缺少的一部分。
1、到学校的图书馆，找到相关书籍，应该有前言或者介绍，如果有英汉对应的话 就如你所愿了2、从学校入口进中国学术期刊全文数据库（这样可免费），在里面搜索相关论文，论文后面肯定有英文参考文献，你就按上面提供的名称找吧~~3、把“基于单片机控制的直流恒流源的设计”翻译成英文，然后在 尽情的找吧4、求助你的指导老师，他知道你的论文嘛，肯定有这方面的资料的如果可以的话，晚上我帮你找找~~现在么资源利用~~呵
自己去百度文库找！什么资料都有！
B2B eMarketplaceAnnouncements and Shareholder WealthThe advent of the Internet as an instrument for business commerce has fundamentally altered the economy by ushering in increased efficiencies and more transparent Since businesses started conducting Internet transactions in 1995,the growth has been Forrester Research estimates that worldwide electronic commerce(e-commerce)revenues were about$650 billion in 2000 and projects they will grow to$8 trillion by The greatest impact is in the businessto-business(B2B)sector,where new supply chain models within electronic marketplaces (eMarketplaces)enable companies to significantly lower procurement costs and increase operating B2B eMarketplaces streamline the supply chain by making better use of more The time it takes to match buyers and sellers can be radically reduced,precautionary inventory levels can be lowered,and the range of potential suppliers and distribution outlets can be expanded as geographic boundaries Projections of online B2B revenues differ vastly,primarily because defining what counts and how to count it varies But despite these differences,forecasters agree that online B2B trade will grow B2B e-commerce is generally believed to account for about 80 to 90 percent of total e-commerce Forecasts typically project USline B2B revenues of about$2 trillion by 2003,up from roughly$336 billion in B2B e-commerce is expected to impact the USy Brookes and Wahhaj(2000)argue that the rapid growth of B2B e-commerce will have an economic impact over and above that of the normal process of innovation and productivity They suggest that as a result of B2B e-commerce,annual GDP growth in the large industrialized countries should rise an average 25 percent for the next ten years—with the level of GDP eventually 5 percent higher than it would otherwise have Brookes and Wahhaj conclude that the dominant long-run effect of B2B e-commerce will be on output and equity markets,rather than on inflation and bond 全文内容省略Investors should respond favorably to announcements of new B2B e-commerce initiatives,as long as they believe these moves will ultimately result in higher profits and increased productivity without fueling We examine the potential impact of B2B e-commerce initiatives on the New Economy paradigm using the efficient markets hypothesis(Fama et 1969),which implies stock prices reflect all available information about individual companies and about the economy as a Information is the key So in efficient capital markets,prices will immediately adjust to reflect any new Thus,B2B e-commerce announcements should immediately raise stock prices if investors believe a firm’s value will be increased by higher net future cash flows resulting from higher productivity,lower costs, or higher
我刚好也这专业的我记得有一个什么论文网 全是PDF格式的论文 好像新注册可以免费下载5篇的 毕竟久了 记不太清什么网你慢慢找吧 那里文献很多
在上面找到的都是你自己可以完成的，建议还是直接找别人写一篇比较保险！我和我同学找的是脚印代写论文写的，用支付宝担保交易很有保障，并且现在论文过了，所以才推荐给你，建议去看看，百度一下就知道了
你可以在google 学术里去搜索你要的论文，你可以把你想要搜的关键词翻译成英文的，然后在google学术里搜索，有些是可以下载的！因为我经常用!希望被采纳！
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T DONT NO
This article described the three directions (before, left, right) ultrasonic ranging system is to understand the front of the robot, left and right environment to provide a movement away from the (Similar to GPS Positioning System) A principle of ultrasonic distance measurement 1, the principle of piezoelectric ultrasonic generator Piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to Ultrasonic generator, the internal structure as shown in Figure 1, it has two piezoelectric chip and a resonance When it's two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is Conversely, if the two are not inter-electrode voltage, when the board received ultrasonic resonance, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, then it becomes the ultrasonic 2, the principle of ultrasonic distance measurement Ultrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiver immediately stop the Ultrasound in the air as the propagation velocity of 340m / s, according to the timer records the time t, we can calculate the distance between the launch distance barrier (s), that is: s = 340t / 2 Ultrasonic Ranging System for the Second Circuit Design System is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 8751, economic-to-use, and the chip has 4K of ROM, to facilitate Circuit schematic diagram shown in Figure Draw only the front range of the circuit wiring diagram, left and right in front of Ranging Ranging circuits and the same circuit, it is 1,40 kHz ultrasonic pulse generated with the launch Ranging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to puzel: mov 14h, # 12h; ultrasonic firing continued 200ms here: cpl 0; output 40kHz square wave nop; nop; nop; djnz 14h, here; ret Ranging in front of single-chip termination circuit P0 input port, single chip implementation of the above procedure, the P0 port in a 40kHz pulse output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of Ranging the right and the left side of the circuit, respectively, then input port P1 and P2, the working principle and circuit in front of the same 2, reception and processing of ultrasonic Used to receive the first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC IC2 is locked loop with audio decoder chip LM567, internal voltage-controlled oscillator center frequency of f0 = 1/1R8C3, capacitor C4 determine their target R8-conditioning in the launch of the carrier frequency on the LM567 input signal is greater than 25mV, the output from the high jump 8 feet into a low-level, as interrupt request signals to the single-chip Ranging in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with output gate IC3A access INT1 port single-chip, while single-chip P3 and P 4 received input IC3A, interrupted by the process to identify the source of inquiry to deal with, interrupt priority level for the first left right Part of the source code is as follows: receive1: push psw push acc clr ex1; related external interrupt 1 jnb 1, right; P1 pin to 0, ranging from right to interrupt service routine circuit jnb 2, left; P2 pin to 0, to the left ranging circuit interrupt service routine return: SETB EX1; open external interrupt 1 pop? acc pop? psw reti right: ?; right location entrance circuit interrupt service routine ? Ajmp? Return left: ; left Ranging entrance circuit interrupt service routine ? Ajmp? Return 4, the calculation of ultrasonic propagation time When you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received When you receive the ultrasonic reflected wave, the receiver circuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance Some of its source code is as follows: RECEIVE0: PUSH PSW PUSH ACC CLR EX0; related external interrupt 0 ? MOV R7, TH0; read the time value MOV R6, TL0? CLR C MOV A, R6 SUBB A, # 0BBH; calculate the time difference MOV 31H, A; storage results MOV A, R7 SUBB A, # 3CH MOV 30H, A? SETB EX0; open external interrupt 0 POP ACC? POP PSW RETI Fourth, the ultrasonic ranging system software design Software is divided into two parts, the main program and interrupt service routine, shown in Figure 3 (a) (b) (c) Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving Interrupt service routines from time to time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to read the value of completion time, distance calculation, the results of the output and so V CONCLUSIONS Required measuring range of 30cm ~ 200cm objects inside the plane to do a number of measurements found that the maximum error is 5cm, and good Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement Therefore, it can be used not only for mobile robot can be used in other detection Thoughts: As for why the receiver do not have the transistor amplifier circuit, because the magnification well, CX20106 integrated amplifier, but also with automatic gain control level, magnification to 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency
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该刊期刊级别是CSCD、北大核心、科技统计源核心。它的任务是反映我国电子科学与信息技术的最新研究成果和技术进展。