On the Analysis of the Virtual Waiting Time in Open Queueing Networks

The model of an open queueing network in heavy traffic has been developed. These models are mathematical models of computer networks in heavy traffic. A limit theorem has been presented for the virtual waiting time of a customer in heavy traffic in open queueing networks. Finally, we present an application of the theorem—a reliability model from computer network practice.     

Barlow-wu continuum systems: A discussion on the model

Summary Barlow-Wu continuum structure functions have been introduced in the past as one particularly interesting family of continuum structure functions. In this paper we provide an alternative characterization for such continuum structure functions, showing other interesting properties. Research supported by Dirección General de Investigación Científica y Técnica (DGICYT), national grants number PB91-0389 and number BE91-225.     

BGA焊点的形态预测及可靠性优化设计

制定了BGA(球栅阵列)焊点的形态预测以及可靠性分析优化设计方案，对完全分布和四边分布的两种BGA元件，通过改变下焊盘的尺寸得到不同钎料量的焊点，并对其形态进行了预测，建立了可靠性分析的三维力学模型。采用有限元方法分析了元件和焊点在热循环条件下的应力应变分布特征，预测了不同种类和不同形态的BGA焊点的热疲劳寿命，由此给出了最佳的上下焊盘比例范围。     

Redundant paths and reliability bounds in gamma networks

Multistage Interconnection Networks (MINs) are network systems providing fast and efficient communications at a reasonable cost. A gamma network is a specific class of MINs, which provides redundant paths in the system. In a gamma network, information from source nodes is transmitted through a specific set of routes to destination nodes. Reliability of an MIN is used as a measure of system’s ability to transform information from input to output devices. Due to the complexity of network configuration and availability of redundant paths, reliability bounds to estimate the exact reliability of a gamma network is proposed. A numerical example of an 8 × 8 gamma network is presented to demonstrate the accuracy of the reliability bounds. When the lower bound reliability provides sufficient assurance that the system will be operational at some specified time and closely approximates the exact reliability, then no further effort for obtaining the exact reliability expression is necessary.     

网格状网络的设计探讨

网格状网络正日益成为核心传送网首选的建网方式。着重介绍了网格状网络的特点和优势，构建网格状网络需考虑的因素及步骤。     

QJ48型比较电桥检定QJ36型电桥方法

提出了利用QJ48电桥对QJ36检定的新方法,结合整体检定的方便与元件检定的准确,实现不开盖对QJ36进行元件检定。     

均匀设计在研究C/Cu复合材料耐磨损设计准则中的应用

本文用均匀设计安排 Ｃ／ Ｃｕ 复合材料的磨损试验，用逐步回归方法建立了可靠度与载荷ｐ、速度ｖ 的回归方程，它有助于对 Ｃ／ Ｃｕ 复合材料磨损性能设计准则进行研究     

HL-2M 装置烘烤系统管路应力的仿真分析与优化

根据 HL-2M 装置烘烤系统管路设计,建立烘烤系统的管道应力计算模型。对烘烤系统管路作初始 支架设计,并采用系统内的最高温度分布,对烘烤系统进行热应力计算,分析管道应力及设备管口载荷。以热应 力计算结果为依据,对管路布置进行优化,并改善支架的设计,对烘烤系统进行应力校核计算,完成烘烤系统可 靠性验证计算,完成了管口位移量计算。     

关于G.657光纤的一些关键问题

根据ITU-TG.657最新版本介绍了G.657光纤的最新要求的变化,并根据ITU-TSG15会议的最新文稿介绍了国际上对G.657光纤可靠性和寿命的最新研究成果。     

基于Credence Gemini500的内嵌式AD转换器测试方法研究

本文中应用Credence公司的Gemini500测试系统对某一SoC芯片内嵌模数转换器进行了测试。根据芯片功能分析和封装形式,对测试板进行了优化设计。根据内嵌式ADC的时序特点进行了测试向量的设计。