Stopping Criteria for Anisotropic PDEs in Image Processing

A number of nonlinear diffusion-like equations have been proposed for filtering noise, removing blurring and other applications. These equations are usually developed as time independent equations. An artificial time is introduced to change these equations to parabolic type equations which are then marched to a steady state. In practice the time iteration is stopped before the steady state is reached. The time when to stop the iteration is usually determined manually for each case. In this study we develop a more automatic procedure for stopping the time integration.     

Timing Models and Local Stopping Criteria for Asynchronous Iterative Algorithms

Asynchronous iterative algorithms can reduce much of the data dependencies associated with synchronization barriers. The reported study investigates the potentials of asynchronous iterative algorithms by quantifying the critical parallel processing factors. Specifically, a time complexity-based analysis method is used to understand the inherent interdependencies between computing and communication overheads for the parallel asynchronous algorithm. The results show, not only that the computational experiments closely match the analytical results, but also that the use of asynchronous iterative algorithms can be beneficial for a vast number of parallel processing environments. The choice of local stopping criteria that is critically important to the overall system performance is investigated in depth.     

Hierarchical Test Sequencing for Complex Systems

Testing complex systems, such as the ASML TWINSCAN lithographic machine, is expensive and time consuming. In a previous work, a test sequencing method to calculate time-optimal test sequences has been developed. Because complex systems are composed of several subsystems, which are again composed of several modules, there exists a need to hierarchically model test sequencing problems. Such a hierarchical test sequencing problem consists of a high-level model that describes a test sequencing problem at the system level, and one or more low-level models that describe the test sequencing problems at the subsystem or module level. The tests at the system level correspond to the solutions of low-level problems. This paper describes a hierarchical test sequencing model and proposes two algorithms to compute an optimal test sequence. The benefits of hierarchically modeling a problem are less computational effort and less modeling effort, because not all relations are needed. This is illustrated by a small example. The industrial relevance of this method is illustrated on a case study related to a manufacturing testing phase of a lithographic machine.     

Integration and Test Sequencing for Complex Systems

The integration and test phase of complex manufacturing machines, like an ASML lithographic manufacturing system, is expensive and time consuming. The tests that can be performed at a certain point in time during the integration phase depend on the modules that are integrated and, therefore, on the preceding integration sequence. In this paper, we introduce a mathematical model to describe an overall integration and test sequencing problem, and we propose an algorithm to solve this problem. The method is a combination of integration sequencing and test sequencing. Furthermore, we introduce several strategies that determine when test phases should start. With a case study within the development of a software release that is used to control an ASML lithographic machine, we show that the described method and strategies can be used to solve real-life problems.      

一种新的测试集简化的测试覆盖准则

在回归测试过程中,测试集的规模不断的变大增加了测试的成本.结合某种测试准则利用测试简化法对测试集中冗余的测试用例进行删除是一种有效的解决方法.但是用此方法得到的简化测试集,其错误检测能力往往被减弱.因此提出了一种新颖的测试覆盖准则,即二级变量串联覆盖准则和二级变量并联覆盖准则.这两种准则主要考虑了变量间的串、并联关系对程序的影响.用此准则与其它测试覆盖准则相组合,利用HGS测试集简化法对测试集进行选择,既简单高效又保证了最小化测试集的错误检测能力.针对文献[3]中的具体应用实例,验证了该测试覆盖准则的有效性.     

基于蚁群算法的系统级序贯测试优化研究

针对系统故障诊断中的序贯测试优化问题,文章采用蚁群算法,把系统级测试序列优化问题转换为蚁群建立最小完备测试序列的问题;通过构建蚁群的状态转移规则和信息素反馈机制,实现对系统级测试序列的优化;实例证明此算法具有良好的性能和可行性,有效地解决了系统级的序贯测试优化问题.     

计算网格中基于风险的模糊策略

针对计算网格的动态性特点,提出一种基于风险的模糊策略,实现对网格资源更灵活有效的分配．首先,研究了基于连续双向拍卖的网格资源分配框架．然后分析了Risk-Based策略,并将模糊理论与Risk-Based策略相结合,提出了基于风险的模糊策略．实验表明,在动态环境中,基于风险的模糊策略优于其他代理策略,能够实现较高的市场效率,市场效率超过99%,并且交易价格快速收敛于市场均衡价格．     

基于蚁群算法的雷达系统测试序列优化研究

随着微电子技术的发展,电子装备结构、功能日趋复杂,电子装备的保障面临的困难也越来越大。文章以多信号模型为基础,以提高电子装备故障诊断能力为目的,开展了测试性分析和基于蚁群算法的测试序列优化研究。最后通过实例证实了算法的可行性和有效性,为雷达系统的测试诊断和功能验证提供了一种新的方法。     

Program Testing Complexity and Test Criteria

This paper explores the testing complexity of several classes of programs, where the testing complexity is measured in terms of the number of test data required for demonstrating program correctness by testing. It is shown that even for very restrictive classes of programs, none of the commonly used test criteria, namely, having every statement, branch, and path executed at least once, is nearly sufficient to guarantee absence of errors.     

基于块的测试充分性度量准则及其测试复杂性度量

1 引言近年来,计算机已广泛应用于银行、证券、工业控制、医疗、交通、航空、航天等领域。在这样的应用领域中,软件的正确性往往关系到人民生命财产和生态环境的安危。一旦软件发生故障,就可能造成生命财产的巨大损失和生态环境的极大破坏。所以,设计人员和使用人员都希望在将软件系统投入运行之前,能得到系统正确性的保证,或能将系统正确性提高到比较高的程度。以软件测试为中心的软件质量保障技术在软件生产实践中得到了迅速的发展,软件测试已成为软件生产中必不可少的质量保障手段。     

Test of Inseparability Criteria for Squeezed Number States of the Radiation Field

We investigate the efficiency of inseparability criteria in detecting the entanglement properties of two-mode non-Gaussian states of the electromagnetic field. We focus our study on the relevant class of two-mode squeezed number states. These states combine the entangling capability of two-mode squeezers with the non-Gaussian character (nonclassicality) of number states. They allow for some exact analytical treatments, and include as a particular case the two-mode Gaussian squeezed vacuum. We show that the generalized PPT criterion recently proposed by Shchukin and Vogel, based on higher order statistical moments, is very efficient in detecting the entanglement for this class of non-Gaussian states.     

常用的基于控制流的测试充分性准则

本文介绍了几种在软件测试中常用的基于控制流的测试充分性评价准则。这些测试充分性准则适用于用过程式语言、面向对象语言编写的程序。测试人员可用这些准则判断究竟测试了多少代码,还有多少代码未测试到。     

数据流测试准则之间关系的研究

软件测试充分性准则是决定一个软件系统能否被充分测试的规则,而测试充分性的关键问题是其检测故障的能力。该文首先分析了数据流测试基本概念,然后讨论了数据流测试准则之间的关系,最后针对测试准则C1和C2,提出了二者的关系R。R(C1,C2)可保证在特定的错误检测度量方法下,C1比C2具有更好的检错能力。     

Stopping criteria for statistical testing

The decision to stop testing can be based on a number of criteria, such as (1) the confidence in a reliability estimate; (2) the degree to which testing experience has converged to the expected use of the software; and (3) model coverage criteria based on a degree of state, arc, or path coverage during crafted and random testing. In practice it is best to use multiple stopping criteria. For example, further evaluation of the testing performed is needed if the measure of correspondence between testing experience and expected use of the software indicates that the testing experience closely matches the expected use of the software, yet the variance of the reliability estimate is unacceptably large. One test of equality of testing experience and expected use is the Kullback discriminant from the usage chain to the testing chain. A new measure of “approximate equality” is introduced here for use in conjunction with the Kullback discriminant.     

基于风险的PKI交叉认证模型研究

探讨了传统的公钥体系结构(PublicKeyInfrastructure,PKI)的缺陷,从信任管理角度,在基于风险的数字证书认证框架基础上,提出了PKI交叉认证的实现模型。模型包括基于风险的信任管理体系结构,终端证书的信任值计算方法及其实现算法,以及证书信任策略。     

基于测试充分性准则的非死锁并发缺陷定位方法

并发程序的非确定性使得其调试工作异常困难。基于程序谱的软件缺陷定位方法虽然能够缓解该情况,但其定位结果依赖于调试信息。针对在此过程中难以获得调试信息及如何选择利用调试信息的问题,提出了一种基于测试充分性准则的缺陷定位方法,该方法包括3个部分:预测满足测试充分性准则的条件;制定相应的测试方案;将收集到的调试信息用于缺陷定位分析。依据此方法,用C#语言实现了缺陷定位工具——ConFinder。在含有实际并发缺陷的程序上进行实验,结果表明该方法可以有效找出引起程序失效的原因并且所得结果具有很好的稳定性。     

程序交互执行流程图及其测试覆盖准则

文章提出一种程序交互执行流程图PIEF(program interactive execution flow chart),用于描述一个交互式软件的各种可能的交互执行过程.基于被测程序的交互执行流程图,进一步提出了功能测试的若干基本的测试覆盖准则、测试用例生成策略及其自动化方法.     

基于事件约束的分布式程序正确性测试

由于并发的存在和不确定性,在以规约为基础来测试分布式程序的正确性时,必须考虑程序 执行时的内部状态.这些内部状态通过端口显示为事件序列,程序规约需要对序列中各事件间 的依赖关系作约定,即定义事件约束集.该文提出了E-CSPE(extended-constraints on suc ceeding and preceding events),以形式化描述这类事件约束,它由3个基本描述规则组成, 分别对应于3种不同类型的事件约束.通过判断程序执行时所产生的事件序 列集同这些事件约束集的一致性以及对约束集覆盖程     

A New Learning Algorithm for Optimal Stopping

A linear programming formulation of the optimal stopping problem for Markov decision processes is approximated using linear function approximation. Using this formulation, a reinforcement learning scheme based on a primal-dual method and incorporating a sampling device called ‘split sampling’ is proposed and analyzed. An illustrative example from option pricing is also included.