无回溯并行多路径搜索测试向量生成算法

无回溯并行多路径搜索算法（NBMP）在生成测试向量过程中生成基于原始输入端奇异立方和与原始输出端关联的传输立方,并利用生成的奇异立方和传输立方生成测试向量。算法在实现过程采用无须回溯和多路径探索策略。通过分析和实验结果证明算法时间复杂度近似为线性。算法对ISCAS85基准电路中规模最大的8个电路进行实验,将实验结果与传统算法进行比较,结果表明NBMP算法故障覆盖率优于传统算法。     

数模混合电路测试与故障诊断方法研究

随着数模混合电路的广泛应用以及对可靠性要求的日益提高,测试与故障诊断成为其设计和维护的两个重要方面;由于数字电路和模拟电路测试与故障诊断的理论基础不同、电路响应的特征不同,因此如何建立模拟电路与数字电路故障诊断的统一模型,如何进行统一测试是混合电路故障诊断的核心问题之一;以解决上述问题为目的,对现有的方法进行了研究和总结,结合最新的研究成果,对混合电路故障诊断的发展趋势进行了展望.     

Cultural algorithm for minimization of binary decision diagram and its application in crosstalk fault detection

The binary decision diagrams (BDDs) can give canonical representation to Boolean functions; they have wide applications in the design and verification of digital systems. A new method based on cultural algorithms for minimizing the size of BDDs is presented in this paper. First of all, the coding of an individual representing a BDDs is given, and the fitness of an individual is defined. The population is built by a set of the individuals. Second, the implementations based on cultural algorithms for the minimization of BDDs, i.e., the designs of belief space and population space, and the designs of acceptance function and influence function, are given in detail. Third, the fault detection approaches using BDDs for digital circuits are studied. A new method for the detection of crosstalk faults by using BDDs is presented. Experimental results on a number of digital circuits show that the BDDs with small number of nodes can be obtained by the method proposed in this paper, and all test vectors of a fault in digital circuits can also be produced.     

基于模型的软件接口故障注入测试平台技术

针对软件接口类型多、接口故障注入自动控制复杂的困难以及目前缺少有效的软件接口故障注入工具现状,对软件故障注入中的交联接口故障注入技术展开研究,提出了一种基于模型的软件接口故障注入测试平台技术。通过交联接口测试可视化建模和接口故障注入算子设计,自动生成XML 格式的测试用例,并且通过基于XSLT的脚本自动化生成与执行技术实现测试的控制与执行。故障注入测试主机与接口故障注入器网络连接,接口故障注入器将接口故障数据转换成以太网、串口或CAN网络数据注入到被测软件中,并返回被测件输出数据到测试主机实现测试数据收集与判断。基于模型的软件接口故障注入测试平台具有较强的通用性与易用性,提高了接口故障注入测试的效率,降低了接口测试的成本。     

Physically accurate nonlinear models for fault detection and diagnosis: the case of a power plant

This paper deals with two main contributions. The first is the definition of an accurate nonlinear model of a section of a real 320 MW power plant. Within the framework of this global method, the second contribution is the modelling of the most common faults that may occur in plants like the one considered in the paper. All these models allow the simulation of the system both under normal working conditions and under anomalous conditions due to the occurrence of one of the faults modelled. The simulated model can be integrated with the automation system of the plant and used in real time, thus providing the plant technicians with crucial information on the plant behaviour, for instance, fault detection and diagnosis can be accomplished in a natural way. Simulation results and comparisons with real data show the effectiveness of the proposed approach.     

存储器测试算法的实现

存储器测试算法的选择以及测试的实现方法是存储器测试的关键。本文在对存储器的故障模型分析的基础上,对具有代表性的测试算法进行了深入的研究,并采用软件实现法将一些典型的测试图形在我所的BDS-9110测试论断系统上进行了实现,生成了存储器检测图形库。利用该图形库作者对980JX系统的存储器模块980/164进行了测试。在研究和实验的基础上,对O(N)类的跨步算法进行了优化。     

扫描链故障确定性诊断向量生成算法

扫描技术是一种广泛采用的结构化可测试性设计方法,是提高测试质量的有效手段.但由于扫描链及其控制逻辑可能会占到整个芯片面积的30%,因此扫描链故障导致的失效可能会达到失效总数的50%.提出一种扫描链故障确定性诊断向量生成算法:首先建立了诊断扫描链故障的电路模型,利用该模型可以采用现有固定型故障测试生成工具产生扫描链诊断向量;然后提出一种故障响应分析方法,以有效地降低候选故障对的数量,从而在保障诊断质量的前提下减少诊断向量数目,缩短了诊断过程的时间.实验结果表明,在测试诊断精确度、故障分辨率和向量生成时间方面,该算法均优于已有的扫描链诊断向量生成方法.     

针对串扰引起的时延故障的测试产生

串扰的出现可能会导致电路出现逻辑错误和时延故障．因此,超深亚微米工艺下,在设计验证、测试阶段需要对串扰问题给予认真对待．由于电路中较长的通路具有较短的松弛时间,因此容易因为串扰问题产生时延故障．针对这类故障给出了一个考虑较长通路上串扰现象的时延故障测试产生算法,该算法采用了波形敏化技术．实验结果表明,采用文中的技术可以对一定规模的电路的串扰时延故障进行测试产生．     

含存储器数字电路系统的自动测试生成

已有的数字电路自动测试生成(ATPG)软件没有存储器的结构模型，不支持对存储器电路的自动测试生成。该文分析了2类存储器的功能特征，提出了面向测试的ROM和RAM结构模型的建立方法，其中，ROM根据所储存的数据等效成组合电路模型， RAM利用新建立的RAMBIT基元等效成利于测试的时序电路模型。将其应用于ATPG软件中，解决了含存储器数字电路的自动测试生成问题。     

基于MAF模型的串扰时延故障的测试矢量生成

随着深亚微米技术,串扰噪声问题越来越严重。利用MAF模型的基本思想,探讨了一种串扰时延最大化算法,并且利用被修改的FAN算法,生成测试矢量。对于一条敏化通路,利用被修改的FAN算法适当地激活相应的攻击线和受害线,使电路在最恶劣情况下引起最大通路时延,从而实现更有效的时延测试。在标准电路ISCAS’85上进行实验验证,结果表明:该算法对于多攻击线的串扰时延故障的测试矢量产生是有效的。     

An extended systematic literature review on provision of evidence for safety certification

ContextCritical systems in domains such as aviation, railway, and automotive are often subject to a formal process of safety certification. The goal of this process is to ensure that these systems will operate safely without posing undue risks to the user, the public, or the environment. Safety is typically ensured via complying with safety standards. Demonstrating compliance to these standards involves providing evidence to show that the safety criteria of the standards are met.ObjectiveIn order to cope with the complexity of large critical systems and subsequently the plethora of evidence information required for achieving compliance, safety professionals need in-depth knowledge to assist them in classifying different types of evidence, and in structuring and assessing the evidence. This paper is a step towards developing such a body of knowledge that is derived from a large-scale empirically rigorous literature review.MethodWe use a Systematic Literature Review (SLR) as the basis for our work. The SLR builds on 218 peer-reviewed studies, selected through a multi-stage process, from 4963 studies published between 1990 and 2012.ResultsWe develop a taxonomy that classifies the information and artefacts considered as evidence for safety. We review the existing techniques for safety evidence structuring and assessment, and further study the relevant challenges that have been the target of investigation in the academic literature. We analyse commonalities in the results among different application domains and discuss implications of the results for both research and practice.ConclusionThe paper is, to our knowledge, the largest existing study on the topic of safety evidence. The results are particularly relevant to practitioners seeking a better grasp on evidence requirements as well as to researchers in the area of system safety. As a major finding of the review, the results strongly suggest the need for more practitioner-oriented and industry-driven empirical studies in the area of safety certification.