在探讨D2D 对通信技术未来发展的导向作用基础上，明确了影响D2D 系统设计的多个因素，即D2D 设
备发现、资源分配、缓存技术、D2D-MIMO。从而勾画出基于D2D 技术的光纤前传和软件定义网络实现数据/控制分离的扁平化5G 架构，提出负责接入的下层宏/小基站蜂窝网和负责管理的上层网络云的管理机制。将D2D技术、SDN 技术、边缘计算和物联网技术等关键技术引入未来移动通信网络已经成为研究领域的热点，针对与之相关的、未来大规模网络的移动性、QoS 和大数据特性进行了讨论。
On the basis of discussing the guiding role of D2D in the future development of communication technology, this paper makes clear the factors influencing the design of D2D system, namely D2D hypothesis Standby discovery, resource allocation, caching techniques, d2d-mimo.Thus, the flat 5G architecture for data/control separation is outlined based on D2D technology of optical fiber prepreel and software-defined network, and the management mechanism of the lower macro/small base station cellular network responsible for access and the upper network cloud responsible for management is proposed.The introduction of D2D technology, SDN technology, edge computing and Internet of things into the future mobile communication network has become a hot topic in the research field. (2020-03-10, PDF, 592KB, 下载9次)
书名：计算机网络（第五版）
作者: 谢希仁
出版社: 电子工业
《计算机网络(第5版)》自1989年首次出版以来，于1994年、1999年和2003年分别出了修订版。2006年8月本教材通过了教育部的评审，被纳入普通高等教育“十一五”国家级规划教材。《计算机网络》的第5版，在内容和结构方面都有了很大的修改。
全书分为10章，比较全面系统地介绍了计算机网络的发展和原理体系结构、物理层、数据链路层、网络层、运输层、应用层、网络安全、因特网上的音频/视频服务、无线网络和下一代因特网等内容。各章均附有练习题。此外，附录A给出了部分习题的答案和提示。随书配套的光盘中，有全书课件和作者教学中经常遇到的150多个问题及解答，计算机网络最基本概念的演示（PowerPoint文件），以及《计算机网络(第5版)》引用的全部RFC文档等，供读者参阅。
Title: Computer Network (fifth edition)
Author: Xie Xiren
Publisher: Electronics Industry
Computer network (5th edition) since it is first published in 1989, in 1994, 1999 and 2003, respectively, it is corrected and republished. In August 2006, the textbooks is incorporated into the regular higher education "Eleventh Five-Year" national planning materials. In the 5th edition of the "computer network", there had been substantial changes in content and structure.
The book is divided into 10 chapters, more comprehensive and systematic introduction to the development of computer networks and principles of architecture, physical layer, data link layer, network layer, transport layer, application layer, network security, audio/video services on the Internet, wireless networks and next-generation Internet content. The various chapters are accompanied by exercises. In addition, Appendix A gives some answer to the exercises and tips. (2012-07-08, PDF, 17693KB, 下载17次)
利用Voronoi图及其对偶Delaunay三角网研究平面离散点集拓扑邻近稳定区域的计算方法，给出拓扑邻近稳定区域的概念，证明点的拓扑邻近稳定区域必须满足的两个条件，给出点的拓扑邻近稳定区域定量计算模型，并通过试验证明其正确性。
A method to maintain the neighboring relations between each two points in discrete points set is studied based on the delaunay triangulation or the Voronoi diagram. A new concept of the topology stable area is put forward firstly, then the two conditions which the points in the topology stable area should be met are proved by the empty circle rule of the delaunay triangulation, A novel calculation model of the topology stable area of the plane discrete points based on the Voronoi diagram is presented and it’s correctness is proved by the experiment. (2012-03-12, PDF, 1699KB, 下载6次)
协同视频会议系统解决方案
视频会议系统由服务器端软件、客户端软件组成。
视频会议系统是纯软件的解决方案，可运行于互联网、专网、VPN 等多种类型的网
络中，支持B/S 和C/S 架构，方便与企业网站、OA、ERP 等系统无缝整合；支持多台服
务器级联，均衡系统带宽的使用；支持更多用户并发，实现运营级视频会议的应用；实
现远程协同办公、多方视频会议等应用，方便用户部署和使用；除支持桌面终端和大型
会场终端外，还支持VOIP 和标准协议的硬件终端接入，可满足大型会场视频会议、个
人商务视频会议等多种形式会议需求。
Collaborative video conferencing solutions (2011-11-30, PDF, 4123KB, 下载15次)
无线通信网络的发展趋势之一是将各种不同无线接入技术进行融合。多接入选择作为无线资源管理中的关键技术是目前异构网融合的研究热点之一。从用户的利益出发，充分考虑预接入网络的费用、QoS 和稳定性；假定不同的网络运营商之间是彼此竞争的，即没有达成统一的协议，提出了一种结合目标代价函数与层次分析法的动态多接入选择算法。通过对影响因素进行分析和二次判断，建立了网络选择决策模型，仿真结果验证了该算法的正确性与有效性。
Trends in wireless communication network is one of a variety of different wireless access technologies will be integrated. Multi-access radio resource management in selection as the key technology is the integration of heterogeneous networks of research focus. From the user' s interests fully into account the cost of pre-access networks, QoS and stability assumed between different network operators are competing with each other, that did not reach uniform agreement, proposed a combination of objective cost function and level analysis of dynamic multi-access selection algorithm. Through analysis of the factors affecting the judge and the second, the establishment of a network selection decision-making model, simulation results verify the correctness and validity of the algorithm. (2011-07-06, PDF, 2793KB, 下载108次)
针对BP神经网络存在的缺点，本文利用遗传算法能够收敛到全局最优解而
且遗传算法鲁棒性强的特点将遗传算法同神经网络结合起来，不仅能发挥神经网
络的泛化映射能力，而且使神经网络具有很快的收敛性以及较强的学习能力。为
了验证遗传算法优化BP神经网络的有效性，本文将此算法应用到直线一级倒立
摆的稳定控制中，同时利用UbVIEW语言界面开发能力强，并且数据输入、网
络通信、硬件控制简单的优点，制作了倒立摆的仿真控制和实时控制软件。仿真
研究表明，遗传算法优化BP神经网络的控制器设计是可行的，可以很好的实现倒
立摆的稳定控制。
BP neural network for the shortcomings, this paper genetic algorithm can converge to global optimal solution and
And genetic algorithm robustness characteristics of the genetic algorithm combined with neural networks, neural networks can not only play
The generalization ability of network mapping, and the neural network with fast convergence and a strong ability to learn. As
The validation of genetic algorithm to optimize the effectiveness of BP neural network, this algorithm is applied to this line a handstand
Put stability control, and interface development using UbVIEW language ability, and data entry, network
Network communications, hardware, the advantages of simple control, produced a simulation of the inverted pendulum control and real-time control software. Simulation
Studies have shown that genetic algorithm BP neural network controller design is feasible, can achieve a good fall
Li put stability control.
(2011-06-19, PDF, 4684KB, 下载17次)
提出了一种基于广义随即petri网的自动制造系统的性能评估实用模型并用来仿真
Generalized stochastic Petri net (GSPN) modules are used
as basic building blocks to model and analyze complex manufacturing
ystems. This modular approach facilitates an easy model construction
and helps manage the complexity
of modeling large manufacturing
ystems. The structural analysis ensures that the model is live and
bounded, which guarantees that the equivalent Markov chain (MC) will
be ergodic. The temporal analysis is used to derive performance mea-
ures such as average production rates and average in-process invento-
ies. The main advantage
of Petri nets (PN!ˉs) overMC!ˉs is that the
number
of places and transitions only increases slightly as the manufac-
uring system complexity increases, whereas the number of states
in the (2011-03-10, PDF, 1676KB, 下载3次)
在城域网交换机日常维护中经常会发现，一些申告有丢包、大延时甚至瞬间
中断的以太网专线接入故障中都是因为交换机端口设置不规范，将速率和双工模
式设成了自动协商，如果光电收发器和用户端口也都设置为这一状态，那么会导
致使用设置为10Mbps/100Mbps 自适应的光收发器和用户端网卡用户，实际接入
速率为全双工100Mbps，这样的话该用户的实际吞吐能力可达到200Mbps；另一
方面，因有些光收发器或用户端设备不具备自协商功能或被设置为10Mbps
(100Mbps) 全双工， 从而导致交换机端口于用户端设备自协商到10Mbps
（100Mbps）半双工，进而导致接入链路延时大、丢包乃至瞬间中断。
MAN switch in the routine maintenance is often found that some declaration have packet loss, delay or even big moment
Ethernet Private Line Access interrupted because of failure in the switch port settings are not standardized, the speed and duplex mode
Type set into auto-negotiation, if the optical transceiver and the user ports are also set to this state, will lead
To use the set to 10Mbps/100Mbps adaptive optical transceivers and client card users, the actual access
Rate full-duplex 100Mbps, so the actual throughput of the user can achieve 200Mbps another
Respect, because some optical transceiver or CPE does not have auto-negotiation function or set to 10Mbps
(100Mbps) full duplex, leading to a switch port on the CPE from the negotiation to 10Mbps
(100Mbps) half duplex, which led to major access link delay, packet loss and even the moment interrupted. (2011-01-17, PDF, 61KB, 下载3次)
问题：通过CP343-1模块，如何实现2套S7-300之间的以太网通讯？
解答：
我们首先搭建一套测试设备，设备的结构图如下：
2套S7-300系统由PS307电源、CPU314C-2DP、CPU314C-2PTP、CP343-1、CP343-1 IT、PC、CP5611、STEP7组成，PLC系统概貌如下图：
Question: by CP343-1 module, how to implement two sets of S7-300 Ethernet Communication between? Answer: We first build a set of test equipment, equipment chart is as follows: 2 sets of S7-300 systems by the PS307 power supply, CPU314C-2DP, CPU314C-2PTP, CP343-1, CP343-1 IT, PC, CP5611, STEP7 composition PLC system overview as shown below: (2010-09-02, PDF, 1410KB, 下载173次)
该文件是“通讯系统”的电路图实例，本电路图注重于USB2.0、RS232、以太网的连接方法以及外围电路设计，为读者朋友提供一个完整的电路实例。而C6713电路部分，只涉及C6713与三个器件的连接关系，至于C6713的其他部分（如SDRAM、FLASH等）都略去,读者可参考另外相关的章节。
The document is " communication system" circuit instance, the diagram focuses on USB2.0, RS232, Ethernet connection method and the external circuit design, the reader will provide an example of a complete circuit. The C6713 circuit part, only involves the C6713 and the connection of the three devices, as in other parts of C6713 (such as SDRAM, FLASH, etc.) are omitted, the reader may refer to other relevant chapters. (2010-06-24, PDF, 73KB, 下载6次)
自主虚拟人技术在虚拟空间中对人类的形态、运动、行为和认知方式进行模
拟，其目的是使虚拟人能够在没有外界干预的条件下，根据外在与内在的条件进
行自主的行为选择与控制。随着虚拟人角色越来越多地出现在虚拟训练、工业设
计、娱乐等各种应用中，人们对虚拟人的智能化和自主程度提出了更高的要求，
使得自主虚拟人成为了虚拟人研究中的热点问题之一。针对目前自主虚拟人控制
技术中存在的问题，本文对运动控制、感知、路径规划和行为控制等关键性技术
进行了研究。
The technology of autonomous virtual human simulates the figure, motion,
behavior and cognitive style of human beings in virtual environment. The research
aim is to enable the characters to choose and control own behaviors according to the
internal and external conditions without user intervention. With more and more virtual
characters appearing in the applications of virtual training, industry designing and
entertainment, people bring up higher requirements to the intelligence and autonomy
of virtual human.Therefore, the autonomous virtual human has become a hotspot in
the research field of virtual human. To solving the problems in the control of
autonomous virtual human, this paper studied on some key technologies, such as
motion control, perception, path plan and behavior control.
(2010-06-21, PDF, 1848KB, 下载16次)
描述了因特网和IP的主要特征，包括包丢失和时延抖动，并让读者了解数字信号处理器(DSP)和语音编码器在VoIP中所扮演的角色。本书还为读者讲述了如何通过ISDN、xDSL、HFC本地环路或其他途径建立与业务提供商之间的通路，以及目前主要的IP电话协议
Describes the main features of the Internet and IP, including packet loss and delay jitter, and to allow readers to understand the digital signal processor (DSP) and voice coder in the role of VoIP. The book also tells the reader how to ISDN, xDSL, HFC, or other means to establish a local loop between the suppliers and business access, and the current major IP telephony protocol (2010-01-27, PDF, 19055KB, 下载6次)
工业网络协议的设计是网络控制系统分析和设计的重要内容. 网络诱导的延时值越小, 则越有利于系统的稳定和控制
算法的设计. 在工业以太网络通信协议( IECP) 模型中, 工业通信协议一般建立在传输层或是应用层. 通过工业通信模式、数据
报和IECP 通信程序, 详细介绍了IECP 的设计. 提出了网络协议的性能指标,
Industrial network protocol is designed to network control systems analysis and design of important content. The smaller the value of network-induced delay, the more conducive to stability of the system and control algorithm design. In the industrial Ethernet network communication protocol (IECP) model industrial communication protocol generally based on the transport layer or application layer. through industrial communication mode, data reporting and IECP communication program, described in detail IECP design. proposed network protocol performance indicators, (2009-11-17, PDF, 443KB, 下载103次)
哈代是20世纪最优秀的数学思想家，同仁公认他是“真正的数学家是纯粹中最纯粹的”。这篇“自白”是他数学创造力衰退时写下的心酸文字。
在哈代的笔下，数学远远不仅是一门科学，还是艺术，是娱乐，是真善美。
本书刚出版，就被誉为堪与亨利·詹姆斯的笔记媲美的对“创造性艺术家的最佳描述”。
C·P·斯诺的长篇前言满含深情地回顾了哈代的一生，栩栩如生地讲述了他的学术生活和有趣的业余爱好。
Hardy in the 20th century' s best mathematical thinker, colleagues recognized him as " a true mathematician is purely the most pure." This " confession" is his mathematical creativity to write a sad word recession. In Thomas Hardy' s novels, mathematics goes far beyond a science, or art, entertainment, the most sublime. This book just published, praised as worthy of Henry James' s notes comparable to " the best description of the creative artist." C · P · Snow' s lengthy preamble laden with deep feeling reviewed Hardy' s life, vividly recounted his academic life and interesting hobby. (2009-10-15, PDF, 577KB, 下载13次)
摘 要:本文分析了在限幅噪声和高斯噪声环境下,在HFC 网中混合传输AM/ OFDM信号时的误
码特性,并与单载波AM/ QAM系统进行比较,结果表明OFDM系统由于多个子通道的稀释作用,其
抗限幅噪声性能比单载波系统好。
关键词:正交频分复用 HFC 网 限幅噪声 误码率
Abstract :Theoretical analysis is presented for the BER performance of hybrid AM/ OFDM system in the pres2
ence of clipping impulse and Gaussian noise ,and the OFDMBER has been compared with that of the single2car2
rier AM/ QAM system1It is found that ,due to the dilution effect of the subchannels ,OFDM is better than single2
carrier QAM in terms of the ability to resist chipping impulse noise interference1
Key words :OFDM HFC network clipping noise BER (2009-05-28, PDF, 147KB, 下载22次)
本书系统地介绍了数据通信和计算机网络领域的基本内容。在第1版的基础上，修改和增加了新的内容，包括无线和卫星通信、有线电视电缆调制解调器、压缩技术、密码技术、防病毒、100 Mbps以太网、NetWare 4.0、边界网关协议、域名系统、IPv6、异步传送模式 、使用客户/服务器模式来实现文件传送协议及开发Web网页等。在内容和结构安排上，注意理论与实际应用的结合，每章后面既有复习题，又有练习题。本书适合作为计算机科学专业本科生的教材，也可供教师和从事该领域设计或应用的研究人员用做参考书。
err (2008-08-29, PDF, 11520KB, 下载15次)
数据库技术是一门历史弥坚的学科，不像其它的计算机技术会随着时间的推移而变得越来越没有声息。考虑其原因，则是因为信息的爆炸对数据库技术的要求只增不减。在互联网日益发展、壮大的背景下，在因特网普及浪潮持续高涨的情况下，如何让原来在单机中使用的数据库可供多机使用，也成了必然的趋势。
database technology is a historical time; disciplines, Unlike other computer technology will be with the passage of time and become less and less quietly. Its causes, it is because the information explosion of database technology requires only unchanged. The Internet growing, the growth of the background, the Internet wave continued rising popularity of the circumstances, how the original single in the use of the database for the use of multi-machine, has become an inevitable trend. (2007-04-15, PDF, 97KB, 下载38次)
：ARM Linux 在AT91RM9200 平台上的移植，步骤包括下载安装内核源码、建立交叉编译环境及以压缩或非压缩方式配置和编译内核。其文件系统的建立及程序开发均在宿主机上完成，再通过串口、网口或者JTAG口烧写至目标板。
: AT91RM9200 ARM Linux platform in the transplant, steps include download and install the kernel source code, the establishment of cross-compiler environment and to reduce non-compressed mode and kernel configuration. Its file system and the establishment of procedures for the development of both the hosts completed, and through the serial port. JTAG net mouth or mouth-burning target board. (2007-01-24, PDF, 279KB, 下载1186次)
《神经网络设计》的电子版，主要介绍了神经网络的基本结构和学习规则，重点是对这些神经网络的数学分析、训练方法和神经网络在模式识别、信号处理以及控制系统等工程实践问题中的应用。
"neural network design," The electronic version, introduced a neural network to learn the basic structure and rules, the focus is on neural network analysis, training methods and neural networks in pattern recognition, signal processing and control system engineering practices in the application. (2005-12-15, PDF, 6540KB, 下载496次)
华为公司内部资料，硬件工程师必读的，尤其对刚毕业没有任何开发经验的人，它可以带你登堂入室，给你一个良好的开发习惯。
Huawei internal information, hardware engineers required reading, especially right after graduation without any experience in the development, it can take you tap, you develop a good habit. (2005-03-22, PDF, 767KB, 下载4229次)