High-frequency, at-speed scan testing

The authors describe new strategies where at-speed scan tests can be applied with internal PLL. They present techniques for optimizing ATPG across multiple clock domains and methodologies to combine both stuck-at-fault and delay-test vectors into an effective test suite.     

A loop-based apparatus for at-speed self-testing

At-speed testing using external tester requires an expensive equipment,thus built-in self-test(BIST) is an alternative technique due to its ability to perform on-chip at-speed self-testing.The main issue in BIST for at-speed testing is to obtain high delay fault coverage with a low hardware overhead.This paper presents an improved loop-based BIST scheme,in which a configurable MISR (multiple-input signature register)is used to generate test-pair sequences.The structure and operation modes of the BIST scheme are described.The topological properties of the state-transition-graph of the proposed BIST scheme are analyzed.Based on it ,an approach to design and efficiently implement the proposed BIST scheme is developed.Experimental results on academic benchmark circuits are presented to demonstrate the effectiveness of the proposed BIST scheme as well as the design approach.     

A polygraph test for trustworthy structural similarity

Do similarity or distance measures ever go wrong? The inherent subjectivity in similarity discernment has long supported the view that all judgements of similarity are equally valid, and that any selected similarity measure may only be considered more effective in some chosen domain. This article presents evidence that such a view is incorrect for the specific case of relative structural similarity. In this context, similarity and distance measures occasionally do go wrong, producing judgements that can be considered as errors in judgement. This claim is supported by a novel method for assessing the quality of structural similarity and distance functions, which is based on relative scale of similarity with respect to chosen reference objects. The method may be applied either with synthetic graph datasets or with graphs representing objects in an application domain of interest. This work demonstrates the method over synthetic datasets with common measures of structural similarity in graphs. Finally, the article identifies three distinct kinds of relative similarity judgement errors, and shows how the distribution of these errors is related to graph properties under common similarity measures.     

QPSO在结构测试数据生成中的应用研究

针对目前进化算法生成结构测试数据方法存在搜索速度慢、设置参数复杂、易陷入局部最优解等缺陷,提出了一种基于量子粒子群算法的结构测试数据生成方法。该方法采用分支函数叠加法构造适应值函数,将测试数据自动生成问题转化为函数的最优化问题,同时在粒子群算法基础上引入量子理论的思想,提高了算法的收敛性能和全局搜索能力。将其与标准粒子群算法实现结构测试数据自动生成方法进行比较,实验结果表明,该方法能更快生成测试数据。     

The structural complexity of software an experimental test

This research examines the structural complexity of software and, specifically, the potential interaction of the two dominant dimensions of structural complexity, coupling and cohesion. Analysis based on an information processing view of developer cognition results in a theoretically driven model with cohesion as a moderator for a main effect of coupling on effort. An empirical test of the model was devised in a software maintenance context utilizing both procedural and object-oriented tasks, with professional software engineers as participants. The results support the model in that there was a significant interaction effect between coupling and cohesion on effort, even though there was no main effect for either coupling or cohesion. The implication of this result is that, when designing, implementing, and maintaining software to control complexity, both coupling and cohesion should be considered jointly, instead of independently. By providing guidance on structuring software for software professionals and researchers, these results enable software to continue as the solution of choice for a wider range of richer, more complex problems.     

新的结构化测试数据自动生成方法

针对模拟退火算法,遗传算法应用于测试数据的自动生成的局限性,提出了一种基于GEMGA(基因表达散乱遗传算法)的结构化测试数据的自动生成的方法.讨论了路径的选择,提出了将控制流图与数据流图结合起来生成测试路径,通过TriType的分析结果说明了该方法的可行性.根据得到的测试路径将GEMGA应用到测试数据的自动生成,TdType的实验结果表明,GEMGA能生成更高质量的数据,并适用于较大规模的程序.     

结构性自动软件测试的设计方法与实现

阐述了一种自动生成结构性测试用例的设计方法与实现过程.采用广义表数据结构作为源程序的中间表示,在辅助实现结构性测试主要功能的同时,兼顾程序结构可视化.讨论了怎样以适当代价尽量高效全面地生成测试用例,并且提供较易用的使用界面.已经在一个可视化集成开发环境中的程序测试模块得到应用.     

Achieving Quality Outsourcing

As a process that must be planned, managed, and controlled, outsourcing presents quality challenges in the areas of vendor selection and products and services received. Achieving success in the first area depends on establishing procedures to thoroughly assess the vendor's competency and process discipline; in the second, quality is ensured through the requirements definition process, implementation of a formal change management system, and the linking of outsourcer milestones with quality reviews.     

基于演化算法的结构测试数据自动生成方法评述

结构测试数据自动生成是结构测试结构测试数据自动生成方法后,重点对基于演化算法的结构测试数据自动生成方法加以评述.归纳了该方法的基本思想和基本流程,按照适应度函数构造方式的不同将其划分为面向覆盖法、面向距离法和综合法三大类,并结合相关文献分析了这三类方法各自的技术特点,比较了各自的优劣.最后,指出了存在的不足,探讨了发展方向.     

Automatic test case generation for structural testing of function block diagrams

ContextFunction Block Diagram (FBD) is increasingly used in safety-critical applications. Test coverage issues for FBDs are frequently raised by regulators and users. However, there is little work at this aspect on testing FBD at model level. Our previous study has designed a new data-flow test coverage criterion, FB-Path Complete Condition Test Coverage (FPCC), that can directly test FBD structures and effectively detect function mutation errors. Nevertheless, because FPCC scheme involves several data-flow concepts and thus it is somewhat complicated to comprehend and to generate FPCC-complied test cases. An automatic test suite generator for FPCC is highly desirable.ObjectiveThis study designs an automatic test case generator, FPCCTestGen, for FPCC so as to enhance the practicability and acceptance of the FPCC approach.MethodFirst, a supporting infrastructure for performing automatic FBD-to-UPPAAL-for-FPCC transformation is designed. The supporting infrastructure includes templates, declarations, and functions as building blocks for transformation. Then, for each input FBD, represented in PLCopen XML format, FPCCTestGen performs parsing and converts FBD components into corresponding UPPAAL model components using aforementioned building blocks. After that, queries related to FPCC characteristics are submitted to UPPAAL model checker for verification. Finally, the verification traces are analyzed to obtain a FPCC-complied test suite.ResultsA safety injection system is used as a case study. Preliminary results show that the generated test suite achieves the highest FPCC percentage with a near optimal number of test cases.ConclusionThis automatic test case generation tool is effective and thus, can promote the use of the new test coverage criterion. Methodology used in FPCCTestGen is generic and can be applied to test suite generation for other test criteria on data-flow programs.     

Achieving Diagnosis by Consensus

This paper provides an analysis of the collaborative work conducted at a multidisciplinary medical team meeting, where a patient’s definitive diagnosis is agreed, by consensus. The features that distinguish this process of diagnostic work by consensus are examined in depth. The current use of technology to support this collaborative activity is described, and experienced deficiencies are identified. Emphasis is placed on the visual and perceptual difficulty for individual specialities in making interpretations, and on how, through collaboration in discussion, definitive diagnosis is actually achieved. The challenge for providing adequate support for the multidisciplinary team at their meeting is outlined, given the multifaceted nature of the setting, i.e. patient management, educational, organizational and social functions, that need to be satisfied.

Achieving higher SEI levels

Two years or more can pass between formal SEI (Software Engineering Institute) assessments using the Capability Maturity Model (CMM). An organization seeking to monitor its progress to a higher SEI level needs a method for internally conducting incremental assessments. The author provides one that has proven successful at Motorola. A method was developed for assessing progress to higher SEI levels that lets engineers and managers evaluate an organization's current status relative to the CMM and identify weak areas for immediate attention and improvement. This method serves as an effective means to ensure continuous process improvement as well as grassroots participation and support in achieving higher maturity levels. This progress-assessment process is not intended as a replacement for any formal assessment instruments developed by the SEI, but rather as an internal tool to help organizations prepare for a formal SEI assessment. Although the author provides examples in terms of CMM version 1.1, both the self-evaluation instrument and the progress-assessment process are generic enough for use with any (similar) later version of the SEI CMM by updating the worksheets and charts used     

Achieving Global Strategic Advantage

Competitive advantage through global integration can be achieved by firms of modest size and those that have been limited in their geographic scope. The keys to success are strategic partnerships, effective communications and information systems, and a facilitative culture.     

A relation-based method combining functional and structural testing for test case generation

Specification-based (or functional) testing enables us to detect errors in the implementation of functions defined in specifications, but since specifications are often incomplete in practice for some reasons (e.g., lack of ideas, no time to write), it is unlikely to be sufficient for testing all parts of corresponding programs. On the other hand, implementation-based (or structural) testing focuses on the examination of program structures, which allows us to test all parts of the programs, but may not be effective to show whether the programs properly implement the corresponding specifications. To perform a comprehensive testing of a program in practice, it is important to adopt both specification-based and implementation-based testing. In this paper we describe a relation-based test method that combines the specification-based and the implementation-based testing approaches. We establish a set of relations for test case generation, illustrate how the method is used with an example, and investigate the effectiveness and weakness of the method through an experiment on testing a software tool system.     

Harmony search-based test data generation for branch coverage in software structural testing

Test data generation is always a key task in the field of software testing. In recent years, meta-heuristic search techniques have been considered as an effective way to assist test data generation in software structural testing. In this way, some representative test cases with high-coverage capability can be picked out from program input space. Harmony search (HS) is a recently developed algorithm and has been vigorously applied to various optimization problems. In the paper, we attempt to apply harmony search algorithm to generate test data satisfying branch coverage. At the preprocessing stage, the probes used for gathering coverage information are inserted into all branches via program static analysis. At the same time, the encoding and decoding styles between a test case and a harmony are also determined in advance. At the stage of test data searching, the subset of test data that has much stronger covering ability is stored in harmony memory. During the evolution process, one part of test suite is selected and adjusted from the harmony memory, and the other part is randomly generated from input space. Once a test suite is yielded after one-round search, its coverage can be measured by fitness function in our search algorithm. In our work, a new fitness function for branch coverage is constructed by comprehensively considering branch distance and branch weight. Here, the branch weight is determined by branch information in program, that is, the nesting level of a specific branch and the predicate types in it. Subsequently, the computed coverage metric is used for updating the test suite in the next round of searching. In order to validate the effectiveness of our proposed method, eight well-known programs are used for experimental evaluation. Experimental results show that the coverage of HS-based method is usually higher than those of other search algorithms, such as simulated annealing (SA) and genetic algorithm (GA). Meanwhile, HS demonstrates greater stability than SA and GA when varying the population size or performing repeated trials. That is to say, music-inspired HS algorithm is more suitable to generate test data for branch coverage in software structural testing.     

The range error test in the structural identification of linear multivariable systems

Among the approaches that have been proposed in recent years for the identification of discrete-time linear multivariable systems, very efficient procedures are based on the introduction of a set of input-output canonical models and on the separate determination of the process structure (structural identification) and parameters (parametric identification). This paper introduces a new simple test which allows us to perform the structural identification without the drawbacks usually associated with singularity tests. The proposed test gives an a priori prediction of the model performance in order to avoid trial and error procedures in the determination of a suitable structure for the process to be identified.