软件协同开发活动管理的三个模型

本文就如何建立一个支持网络软件协同开发活动的环境和信息系统,如何在此系统中进行任务划分和协同管理等方面展开了讨论,提出了协同活动管理中对象性、关系性和任务性这3个方面的分析模型,并进行了较为深入的设计和讨论,它以软件组件对象为核心描述了对象模型;以"最后离开者关门原则"讨论了关系模型;以任务划分方法分析了任务模型。     

装备测试性建模与分析软件框架设计

现代装备的功能越来越先进,相应的结构和技术也越来越复杂。对于复杂设备的测试和诊断越来越重要。通过装备测试性建模与分析的方法来改善测试性设计,已经成为提高装备测试能力和测试总体优化,进而全面、快速、准确地感知装备技术状态的有效手段。在测试性设计等工作的基础上,设计了装备测试性建模与分析软件。软件结合已有的CARMES 6的FMECA、可靠性预计等模块功能,设计了包括测试性建模、测试性分析等模块,为装备测试性设计提供有力的软件工具支持。     

机载计算机测试性工作及改进方案研究

随着电子技术的飞速发展及电子产品的复杂化,多样化,设备维护和保障的成本会提高,对产品测试性设计水平的要求也越来越高。文章对测试性部分工作项目进行了介绍,利用测试性建模软件TADS对某型机电管理计算机进行了测试性建模和分析,结合故障诊断树提出了测试性改进原则,为测试性改进方案提供了依据。     

面向ATE的电路板测试性分析及评估方法研究

为了客观地评价TPS,保证ATE在电路板测试维修中发挥更大作用,给出了面向ATE的电路板测试性评估方法.通过ATE测试资源分析选择测试点,利用电路故障仿真,建立电路板的测试性模型、生成依赖矩阵,得出电路板故障检测率和隔离率;然后结合ATE测试的可靠性及费用分析,得到电路板平均故障隔离费用和平均故障隔离步数,实现了电路板测试性的综合评估.最后以某装备电路板为例,验证了方法的有效性.     

军用红外车载驾驶仪人机功效分析北大核心CSCD

提出了军用红外车载驾驶仪的人机功效关系模型,从驾驶视野性、视觉舒适性和操纵舒适性三个方面对军用红外车载驾驶仪的人机功效进行了研究。运用理论分析、模拟仿真及实验等方式,分析得出了军用红外车载驾驶仪人机功效的影响因素、评价重点内容及评价准则。研究成果能够为军用红外车载驾驶仪的人机系统设计提供依据,为其人机功效评价提供参考。     

领域变化性分类与控制机制研究

客观世界存在的变化性以及用户的个性化需求,要求软件系统具有足够的灵活性.本文提出了一个开放的变化性控制框架,从组织机构、功能、数据、表示和过程连接等五个维度讨论了变化性出现的根源、变化性表现形式、变化性控制机制和实现技术,提供了一个系统化的变化性解决方案.并以商业领域应用软件开发平台的实践为例,研究变化性控制在特定领域的应用.     

基于空间位置的增量式光电编码器误差检测系统

增量式光电编码器输出信号的正交性和均匀性是其重要技术指标之一,对增量式光电编码器的精度检测是编码器研制和生产过程中的重要环节。传统信号质量的检测是基于时间位置进行检测的,其检测准确度受转速均匀度影响,在高速、变速转动下对增量式光电编码器的动态性能检测并不准确。提出了一种基于空间位置的信号质量检测方法,并设计了相应的检测系统。检测系统采用直流无刷电机带动高精度角脉冲发生器和被检增量式编码器同轴旋转,并采集高精度角脉冲发生器在被检增量式编码器输出信号边沿时刻的数值,进行误差计算。该检测系统极大地减小了由于转速不均匀造成的测量不准确度。运用该检测系统对输出脉冲周期数为32 400的增量式编码器进行检测,并与时间位置检测法进行对比实验。实验结果表明:该检测系统检测结果不受电机转速变化的影响,可有效地提高检测精度及检测效率,能够实现动态检测。该系统的研制为批量生产增量式光电编码器提供了极大的便捷。     

光纤带的操作属性与试验

简要的阐述了光纤带的结构 ,讨论了光纤带的各种操作属性及其试验方法。以三种用不同材料和结构的光纤带为例 ,介绍了试验结果 ,从而说明了光纤带的各项操作属性与光纤带设计之间的关系     

基于节点拓扑结构的复杂网络抗毁性评价方法

复杂网络抗毁性分析主要是实证分析与仿真分析,测度方法存在争议,难以定量描述网络拓扑的抗毁性.分析了当前复杂网络抗毁性的测度方法,提出使用跳面节点方法(Jump node method)衡量网络拓扑的可靠性和抗毁性,为复杂网络拓扑抗毁性比较和"核心节点"评估提供了基础.     

插入Kerr介质的CO_2激光器的动力学行为的理论分析

建立了单模环腔CO_2激光器的数学物理模型。线性稳定性分析的结果表明,当Kerr介质的Debye弛豫速率远远大于激光工作原子的纵向弛豫速率时,系统将在低光强区出现动力学不稳定性。数值计算的结果表明,在恒定泵浦下,激光输出为一系列脉冲,基本上追随倍周期分岔的道路通向混沌。     

Failure-mechanism models for conductive-filament formation

This tutorial illustrates design and qualification situations where conductive filament formation, a failure mechanism that can occur in laminates, can affect product performance. Empirical models to design against this failure mechanism are presented in this paper. Examples illustrate the use of these models for design and qualification tests in electronic packaging     

A communications-based technique for interdisciplinary design teammanagement

A technique for interdisciplinary design team management that focuses on information processing and communication between team members is presented. A cognitive model of communication-related failure mechanisms of design groups is developed. Strategies for defining and assigning subtasks among individuals or subgroups that are based on the communications model are described. A technique for evaluating the expected effectiveness of a design team configuration is also presented. The cognitive model and task definition and assignment strategies are integrated into a tool which is traditionally used to evaluate only the physical design artifact itself, failure modes and effects analysis (FMEA). By determining communication failure mechanisms and how they can affect the design artifact, the authors are able to develop strategies that minimize their impact and an analytic tool to determine design team effectiveness. An illustrative application to the problem of designing a program for computer-assisted instruction is presented     

一款数字信号处理器的失效分析研究

集成电路在实际应用中,经常会出现工作异常甚至失效的情况。当电路发生失效时,需要采用各种手段尽快定位问题所在,在本地复现相关现象,明确问题原因,进而提出针对性的解决方案。介绍一款数字信号处理器电路的失效分析过程。包括问题的出现,现场确认,失效现象复现,借助Latch-up、EMMI设备分析问题,提出改版方案。     

Reliability design of current stress in LSI interconnects using the estimation of failure rate due to electromigration

A method for the flexible and systematic design of the current stress level is proposed to assure reliability concerning electromigration open failure in aluminum interconnects of LSI. The proposed design rule can satisfy reliability requirements without excess restrictions on LSI performance. The required reliability is quantitatively defined using the failure rate and lifetime. The requirements for interconnects are hierarchically decided from LSI reliability design.The equation used in the design is induced using the acceleration factor of the testing condition to the operating condition considering the statistical difference between a test sample and an LSI, and consists of three terms corresponding to reliability requirements, parameters of circuit design and the EM failure resistance of the interconnect technology used.The interconnects in an LSI are classified into those for power use and those for signal use. The solution for each use is represented using a map that follows allowable areas of design parameters. The map makes it easy to change the designed parameters for the purpose of high performance within the reliability requirement limit.The error of the reliability estimation is analyzed as a function of the parameters used in the equations. To avoid optimistic estimations, a safety factor is introduced in relation to the standard deviation of the error.     

浅谈MOSFET产品失效分析及改善措施

阐述了MOSFET产品的应用前景，说明了其封装工艺流程及注意事项，通过对MOSFET电路常见失效现象的分析验证，探讨MOSFET产品的失效机理及其影响，对相应的失效现象制定合理的失效分析方案，确保有效查找失效的具体原因，并对失效原因从设计、工艺和材料选用等方面提出改善措施。     

军用集成电路失效分析

随着科学技术的发展,集成电路在我国军用武器装备上的应用越来越广泛,其可靠性成为制约我国武器装备质量的一项重要因素,失效分析是集成电路可靠性及质量保证的重要环节,本文从失效分析的流程、方法、技术及发展入手,对军用集成电路的失效模式及失效机理进行了详细的讲解,随着元器件设计与制造技术的不断提高及失效分析技术和工具的逐步完善,失效分析工作将在集成电路质量控制方面发挥更大的作用.     

一种FIFO器件的失效模式分析

异步FIFO常应用于在异步时钟域之间进行数据传输。本文根据应用过程中数据帧头重复首字节的异常现象,对FIFO器件M67024的一种失效模式进行分析和说明。进而分析FIFO因设计原理而存在的共性使用要求,并提出针对该类型FIFO失效模式,电路设计人员应当注意的设计规则。     

Application of coupled electro-thermal and physics-of-failure-based analysis to the design of accelerated life tests for power modules

In the reliability theme a central activity is to investigate, characterize and understand the contributory wear-out and overstress mechanisms to meet through-life reliability targets. For power modules, it is critical to understand the response of typical wear-out mechanisms, for example wire-bond lifting and solder degradation, to in-service environmental and load-induced thermal cycling. This paper presents the use of a reduced-order thermal model coupled with physics-of-failure-based life models to quantify the wear-out rates and life consumption for the dominant failure mechanisms under prospective in-service and qualification test conditions. When applied in the design of accelerated life and qualification tests it can be used to design tests that separate the failure mechanisms (e.g. wire-bond and substrate-solder) and provide predictions of conditions that yield a minimum elapsed test time. The combined approach provides a useful tool for reliability assessment and estimation of remaining useful life which can be used at the design stage or in-service. An example case study shows that it is possible to determine the actual power cycling frequency for which failure occurs in the shortest elapsed time. The results demonstrate that bond-wire degradation is the dominant failure mechanism for all power cycling conditions whereas substrate-solder failure dominates for externally applied (ambient or passive) thermal cycling.     

集成电路可靠性应用技术

本文主要论述集成电路加速寿命测试理论方法和IC常见失效模式.加速寿命测试包括定性高加速寿命HALT测试技术和定量加速寿命测试Arrhenius model等,该测试技术主要应用于IC设计前端识别失效模式和IC设计定型阶段估算IC正常使用条件下的寿命信息,及时有效的评估IC设计平均寿命;在电子产品制造系统中,常常有两种失效模式:ESD静电损伤和LATCH-UP失效现象,对以上可靠性指标和理论作简要的论述.     

Fault-tree analysis for system design, development, modification,and verification

A methodology that uses fault-tree analysis (FTA) techniques to assess the weaknesses of a new chemical/process design at any time during system development is presented. FTA provides a cost-effective means of improving or verifying the reliability and efficiency of chemical/process design. It evaluates the consequences of conceivable failure to indicate where improvements are justified. FTA techniques were used to model the failure modes of an existing control-room heating, ventilation, and air-conditioning (HVAC) system of a large production facility. The fault-tree reduction revealed 129 single-, 434 double-, and 442 triple-failure combinations, any of which could cause system failure. Single failures and double failures consisting of an equipment malfunction and an operator failure error were targeted for design and/or procedural modifications. These modifications were then incorporated into the operating system design to enhance system availability. In an iterative fashion, FTA techniques were reapplied to the modified design and used to verify the adequacy of the proposed revisions prior to implementation. This resulted in a thorough review of system vulnerabilities and a clear understanding of how to correct them