Reliability Optimization in Telephone Switching Systems Design

In the design of telephone switching systems, the sequence of reliability design functions can be stated as 1) the formation of reliability objectives, 2) the allocation of these objectives, and 3) the modeling to verify the reliability obtained. Optimization techniques can be used in both reliability allocation and reliability modeling. This paper discusses the formation of reliability objectives and the methods of reliability goal allocation. Modeling examples are presented of a component-level reliability vs. cost trade-off and a system-level reliability analysis.     

优化固定电话交换网络的几点思考

根据全省固定网现状,分别从合理选用机型、优化组建县内交换网络组织两方面,阐述了优化发展固定交换网的方法,并提出了本地网网络优化的几点看法。     

基于鱼群算法的全终端网络可靠性优化设计

鱼群算法是一种新型群智能优化方法,在分析鱼群算法实现原理的基础之上,将其与全终端网络可靠性优化问题有机融合,给出了求解全终端网络可靠性优化问题的鱼群算法设计.通过实例仿真比较,鱼群算法能够得到比遗传算法更满意的结果,从而验证了算法的可行性和有效性.     

Reliability Optimization in Multiloop Communication Networks

The rapidly growing interest in loop communication systems is accompanied by an increasing need to improve their reliability and reduce their vulnerability. This paper analyzes the reliability of multistage loop networks. Analytical expressions for topologies exhibiting maximum availability are obtained in terms of key-component down-time ratios. These optimal topologies are expressed in terms of terminal connections per subloop and subloops per higher level loops. The availability performance of these optimal topologies is investigated. Finally, the availability improvement obtainable by going to higher stage loop networks is investigated.     

ZXPCS无线市话(小灵通)系统的网络规划与优化

介绍了ZXPCS系统网络规划和优化的必要性、网络规划的方法和步骤、网络优化的目的和要求，以及网络优化中基站调整的原则等。     

PIC单片机在楼宇对讲系统的应用

文章介绍了一种采用PIC16C84作为微处理芯片的中档楼宇对讲系统 ,PIC16C80所带的EEPROM数据存储器可以简化系统组成 ,提高可靠性 ,降低成本 ,系统具有较好的应用前景     

语音型电话自动计费器的设计及实现

文章介绍了一种采用AT89C5 1单片机和ISD142 0语音芯片作为主要器件设计的电话自动计费器 ,对其硬件电路和软件的设计进行了详细说明。     

Reliability Assessment Of Computer System Design

This paper is intended to introduce a general purpose software and hardware design reliability assessment methodology based on the analysis of failure occurrence trend previous to modeling of failure processes. The failure data is collected at test phases and during the system operating life time. The maintenance requirement is used to qualify the Tropico R switching system, according to both hardware components and design failures.     

抑制浪涌电流用NTCR可靠性研究

研究了造粒、烧结工艺、原材料、配方组成对抑制浪涌电流用NTCR可靠性的影响。通过合理选择造粒颗粒和烧结温度、选用高质量的原材料,并在配方中添加微量SiO2、CrO3、Sb2O3作为玻璃料可使抑制浪涌电流NTCR的失效率从100ppm降为8ppm.     

A Model for Telephone Networks and Its Use for Routing Optimization Purposes

The problem studied here concerns the modeling of call blocking in telephone networks. From the usual assumptions such as exponential arrivals and holding time, lost call cleared, the state of the network is described by a finite Markov chain. From the transition probabilities of this process are derived the differential equations associated with the average occupancy of all trunk groups. These traffic equations are simplified by considering independence of blocking for trunk groups in series. The blocking probabilities are estimated using fictitious offered traffic and the Erlang B formula. Such representation takes into account peaky or smooth traffic characteristics. We develop this one-moment model for routing policies such as load sharing and overflow routing. Performances of the model are given in comparison to the solution of the exact Markov chain model or the results of Monte Carlo simulation. Finally, an application to routing optimization and network dimensioning is treated.     

SRAM在定时器设计中的应用

文章介绍了SRAM作定时信号存储器件的高精度定时器的设计方法 ;介绍了一种 2 4小时内任意定时的多路输出定时器的设计方法。该定时器定时精度高 ,时间设定方便 ,可任意设置和随时调整定时时间 ,通用性强     

微型机器人足球系统中的通信子系统设计

文章介绍采用RFM公司的RX50 0 0和TX50 0 0系列短距离高频无线收发器 ,实现微型机器人足球系统中的通信子系统的方法。     

企业IP电话网络

论述了IP电话技术及其在企业中的应用提出了基于企业虚拟专用网系统的企业IP电话网络的构建方案,同时对IP电话网络应用的扩展问题做了分析与探讨.     

荆州市本地网优化方案

荆州市本地网优化方案龙平（湖北省荆州市邮电局４３４０００）收稿日期：１９９７１０２７一、概述荆州市扩大本地网于１９９６年建成。扩大本地电话网的建成带来了明显的社会效益和经济效益，同时也提高了网路的运行效率。通信大发展之后必然有一个研究、调整、巩固...     

级联遗传算法优化设计前向神经网络

文章提出了一种新的用遗传算法优化设计前向神经网络结构和权重矢量的方法。这种算法采用二进制与浮点数混合编码 ,对神经网络结构用二进制编码 ,对神经网络权重矢量用浮点数编码 ,并设计了与混合编码相对应的交叉、变异、选择算子 ,既保留二进制编码简单、易操作的优点 ,又具有浮点数编码搜索空间大、精度高、稳定性好、运算速度快的优点。优化算法包括两级级联的遗传算法。第一级遗传算法实现快速的局部寻优 ,而第二级遗传算法提高全局寻优能力。     

The Reliability of Redundant Multiple-Line Networks

This paper develops a procedure for determining a lower bound to the reliability of multiple-line redundant networks. The procedure is general in that there are no restrictions on the interconnection pattern between the functions of the network, and it allows, within limitations, different parts of the network to take on different orders of redundancy. The approximation to reliability is very good if the reliabilities of the circuits in the network are close to unity.     

Error Compensation Of Current Transformers Used In High Voltage Networks

An error compensation technique for measuring current transformers is described. It uses only passive components. An example is shown for current transformers installed in I50 kV switching devices. Initial ratio errors in the order of 4% and phase shifts around 20 min were reduced to 0.1% and 6 min after the compensation. The transformer with the compensation fulfils class 0.2 according to IEC standards.     

WDM光网络广义无阻塞组播通信

文章讨论了一系列典型拓扑 (线阵列、环和网格 )WDM光网络的组播通信 ,并在常规路由算法下 ,导出了WDM网广义无阻塞组播通信时需求最小波长数的充要条件     

Reliability Indices for Topological Design of Computer Communication Networks

Incorporating network reliability parameter in the design of reliable computer communication networks makes the computations prohibitive. Interdependence among network topological parameters does not permit the design of a maximally reliable network using any one of the parameters and thus, there arises a real need for a composite reliability index which gives a more realistic assessment of network reliability. After discussing experimental results regarding the effects of various topological parameters on network reliability, we present two heuristic reliability indices which give a fair indication of overall reliability. A design procedure for reliable computer communication network based on local search technique incorporating these reliability indices is suggested. Having only one composite reliability index which is very simple to evaluate saves computation while designing maximally reliable computer networks as compared to the existing techniques based on several reliability measures.