Evolving assembly programs: how games help microprocessor validation

Core War is a game where two or more programs, called warriors, are executed in the same memory area by a time-sharing processor. The final goal of each warrior is to crash the others by overwriting them with illegal instructions. The game was popularized by A. K. Dewdney in his Scientific American column in the mid-1980s. In order to automatically devise strong warriors, /spl mu/GP, a test program generation algorithm, was extended with the ability to assimilate existing code and to detect clones; furthermore, a new selection mechanism for promoting diversity independent from fitness calculations was added. The evolved warriors are the first machine-written programs ever able to become King of the Hill (champion) in all four main international Tiny Hills. This paper shows how playing Core War may help generate effective test programs for validation and test of microprocessors. Tackling a more mundane problem, the described techniques are currently being exploited for the automatic completion and refinement of existing test programs. Preliminary experimental results are reported.     

Artificial neural networks as multi-networks automated test oracle

One of the important issues in software testing is to provide an automated test oracle. Test oracles are reliable sources of how the software under test must operate. In particular, they are used to evaluate the actual results produced by the software. However, in order to generate an automated test oracle, it is necessary to map the input domain to the output domain automatically. In this paper, Multi-Networks Oracles based on Artificial Neural Networks are introduced to handle the mapping automatically. They are an enhanced version of previous ANN-Based Oracles. The proposed model was evaluated by a framework provided by mutation testing and applied to test two industry-sized case studies. In particular, a mutated version of each case study was provided and injected with some faults. Then, a fault-free version of it was developed as a Golden Version to evaluate the capability of the proposed oracle finding the injected faults. Meanwhile, the quality of the proposed oracle is measured by assessing its accuracy, precision, misclassification error and recall. Furthermore, the results of the proposed oracle are compared with former ANN-based Oracles. Accuracy of the proposed oracle was up to 98.93%, and the oracle detected up to 98% of the injected faults. The results of the study show the proposed oracle has better quality and applicability than the previous model.     

新型落锤冲击试验系统研制

针对现有落锤冲击试验系统无法低成本、高精度地获取冲击全过程中试样的力、位移等参数的技术难题,提出一种新型落锤冲击试验系统。该试验系统采用磁栅尺和动态力传感器直接精确测量被测试件的力与位移数据,通过电磁铁与电动绞盘实现锤头的提升与释放,并利用虚拟仪器LabVIEW实现对冲击试验系统的数字化控制和数据采集分析功能。以304不锈钢圆管为测试样件,通过冲击试验与ABAQUS有限元冲击仿真试验进行对比,结果表明,冲击实测数据与仿真数据吻合较好,证实所设计冲击试验台具有较高的可靠性。     

An experimental comparison of the effectiveness of branch testingand data flow testing

An experiment comparing the effectiveness of the all-uses and all-edges test data adequacy criteria is discussed. The experiment was designed to overcome some of the deficiencies of previous software testing experiments. A large number of test sets was randomly generated for each of nine subject programs with subtle errors. For each test set, the percentages of executable edges and definition-use associations covered were measured, and it was determined whether the test set exposed an error. Hypothesis testing was used to investigate whether all-uses adequate test sets are more likely to expose errors than are all-edges adequate test sets. Logistic regression analysis was used to investigate whether the probability that a test set exposes an error increases as the percentage of definition-use associations or edges covered by it increases. Error exposing ability was shown to be strongly positively correlated to percentage of covered definition-use associations in only four of the nine subjects. Error exposing ability was also shown to be positively correlated to the percentage of covered edges in four different subjects, but the relationship was weaker     

An Experimental Evaluation of Data Flow and Mutation Testing

Two experimental comparisons of data flow and mutation testing are presented. These techniques are widely considered to be effective for unit-level software testing, but can only be analytically compared to a limited extent. We compare the techniques by evaluating the effectiveness of test data developed for each. We develop ten independent sets of test data for a number of programs: five to satisfy the mutation criterion and five to satisfy the all-uses data-flow criterion. These test sets are developed using automated tools, in a manner consistent with the way a test engineer might be expected to generate test data in practice. We use these test sets in two separate experiments. First we measure the effectiveness of the test data that was developed for one technique in terms of the other. Second, we investigate the ability of the test sets to find faults. We place a number of faults into each of our subject programs, and measure the number of faults that are detected by the test sets. Our results indicate that while both techniques are effective, mutation-adequate test sets are closer to satisfying the data flow criterion, and detect more faults.     

信息处理单元测试系统并行测试技术研究

针对信息处理单元测试的功能需求,设计实现了基于PXIe总线的测试系统,系统包括测控单元、供电单元和接口单元三个组成部分,并完成了测试系统的软件设计;根据信息处理单元测试系统实际的测试流程和所需资源的使用情况,将并行测试技术引入到系统中,重新对相互独立的测试任务进行了并行化分析,构建了该测试系统的任务调度数学模型,提出了一种改进的自适应遗传算法(即IAGA算法),解决了并行测试模块中复杂且难以优化的任务调度问题;对任务调度模型进行了算法仿真验证和实验结果分析,验证了所得解的全局性,所得出的执行序列与串行测试相比,测试效率提高了43.57%,并与其他算法进行了对比,验证了IAGA算法的可行性与优越性;最后将IAGA算法嵌入到了测试系统的软件当中,实现了该优化策略的实际工程应用。     

A numerical study of occupant responses and injuries in vehicular crashes into roadside barriers based on finite element simulations

Occupant responses and injuries are important considerations in the design and assessment of roadside safety devices such as barriers. Although incorporating occupant responses and injuries into the design of safety devices is highly recommended by the current safety regulations, there are limited studies that directly consider occupant responses and injuries. Crash test dummies are seldom equipped in the state-of-the-art crash testing of roadside barriers and thus occupant responses and injury risks are evaluated primarily based on vehicle responses. In the present work, occupant responses and injuries in automotive crash events were investigated by incorporating crash test dummies into the vehicle model that was used in the finite element (FE) simulations of roadside crashes. The FE models of a Ford F250 pickup truck and a Hybrid III 50th percentile crash test dummy were employed and a passive restraint system was developed in the FE model. The FE model was validated using existing experiments including a sled test and a full-frontal impact test. Simulations of the Ford F250 impacting a concrete barrier and a W-beam guardrail were conducted and the occupant responses were analyzed. Furthermore, occupant injuries were quantitatively estimated using occupant injury criteria based directly on dummy responses and compared to those based solely on vehicle responses. The correlations between vehicle responses and occupant injuries were studied.     

综合模块化航空电子平台网络故障注入策略

综合模块化航空电子（IMA）平台网络通信结构复杂，在进行故障注入测试时，存在难以选取合适的测试路径及等效、无效故障注入较多的问题。根据IMA平台网络通信结构特点，提出一种新的故障注入策略。首先，根据IMA平台网络对实时性和确定性的要求，提出一种基于通信链路的测试路径优化算法，生成最优测试路径，实现对IMA平台网络测试任务的有序覆盖；然后，在确定测试路径之后，采用有色Petri网（CPN）建模方法搭建测试案例自动生成模型，排除等效与无效故障，精简测路径中每个测试任务所需的测试案例。仿真结果表明，所提方法在测试次数与测试时间等方面均少于传统的故障注入策略，能够克服传统策略中的无序性及盲目性的缺点，降低测试的时间成本。     

Empirical evaluations on the cost-effectiveness of state-based testing: An industrial case study

ContextTest models describe the expected behavior of the software under test and provide the basis for test case and oracle generation. When test models are expressed as UML state machines, this is typically referred to as state-based testing (SBT). Despite the importance of being systematic while testing, all testing activities are limited by resource constraints. Thus, reducing the cost of testing while ensuring sufficient fault detection is a common goal in software development. No rigorous industrial case studies of SBT have yet been published.ObjectiveIn this paper, we evaluate the cost-effectiveness of SBT on actual control software by studying the combined influence of four testing aspects: coverage criterion, test oracle, test model and unspecified behavior (sneak paths).MethodAn industrial case study was used to investigate the cost-effectiveness of SBT. To enable the evaluation of SBT techniques, a model-based testing tool was configured and used to automatically generate test suites. The test suites were evaluated using 26 real faults collected in a field study.ResultsResults show that the more detailed and rigorous the test model and oracle, the higher the fault-detection ability of SBT. A less precise oracle achieved 67% fault detection, but the overall cost reduction of 13% was not enough to make the loss an acceptable trade-off. Removing details from the test model significantly reduced the cost by 85%. Interestingly, only a 24–37% reduction in fault detection was observed. Testing for sneak paths killed the remaining eleven mutants that could not be killed by the conformance test strategies.ConclusionsEach of the studied testing aspects influences cost-effectiveness and must be carefully considered in context when selecting strategies. Regardless of these choices, sneak-path testing is a necessary step in SBT since sneak paths are common while also undetectable by conformance testing.     

基于优化编码的LFSR重播种测试压缩方案

大规模高密度集成电路测试中存在测试数据量大、测试功耗高等问题.提出了一种先通过编码优化测试集,再使用线性反馈移位寄存器(linear feedback shift register,LFSR)重播种的内建自测试方案.该方案通过自动测试模式生成工具得到被测电路的确定测试集,再压缩为种子集存储在片上ROM中.压缩测试集的过程中,首先以降低测试功耗为目标,用少量确定位编码测试集中的部分测试立方,来增强解码后测试模式相邻位之间的一致性;然后以提高压缩率同时降低LFSR级数为目标,将测试立方编码为确定位含量更少的分段相容码(CBC),最后将以CBC编码的测试立方集压缩为LFSR种子集.实验证明所提出的方案在不影响故障覆盖率的前提下大量降低了测试功耗,并且具有更高的测试数据压缩率.     

基于虚拟仪器技术的机载产品测试系统研制

为保证某型飞机机上飞控系统的供电安全性,针对某型机载产品的测试特点及其测试需求,研制一种基于LabVIEW开发平台的某型飞机机载产品专用测试系统,重点对测试系统硬件与软件选型进行分析与设计,通过软件开发和系统功能测试验证。结果表明：该系统的运行可靠稳定,可以满足该型机载产品各项性能的测试需求。     

基于DSP的自旋弹姿态存储测试方法

本文针对姿态信息测试仪的低精度、体积大、抗过载能力差等问题,提出了一种基于DSP的姿态存储测试方法,选用陀螺和地磁传感器组合测试,用DSP来控制,并在DSP内部设计卡尔曼滤波器解算姿态信息并存储。通过仿真和转台实验得出数据分析,验证了此方法的可靠性和可行性,达到了高测试精度的要求,同时还对所设计的记录仪进行了抗过载实验,结果表明完全可以用于高过载下的姿态测试试验,为以后的弹载姿态信息测试提供了新的方法。     

IPv6基本首部的Petri网建模及测试生成

使用渐增式建模的方法,建立了IPv6基本协议中基本首部的Petri网模型,并开发自动测试生成工具ATSG,得到的IPv6基本描述协议一致性测试套,该测试套可用于实际测试。最后以基本首部的下一个首部字段为例,给出了TTCN测试例。     

针对规则更新操作的测试数据包选取算法*

防火墙规则集中存在的配置错误主要来源于规则的添加、删除等更新操作。因此进行规则更新时,需要使用测试算法判断更新操作的正确性。现有的测试算法仅从被添加或被删除规则的顶点选取测试数据包,不能检测出所有因规则冲突而导致的配置错误。基于此,提出了一种针对规则更新操作的测试数据包选取算法PCRU。该算法从两处选取测试数据包,即被添加或者被删除的规则的顶点和规则冲突区域。理论分析和仿真实验表明,与现有测试算法相比,在进行规则更新时,PCRU算法只需使用少量的测试数据包,即可检测出所有因规则冲突而导致的配置错误。     

基于地铁制动系统的测试装置研究与开发

详细分析了地铁车辆电空制动系统的工作原理,提出了基于地铁制动系统的测试装置的设计方案。通过硬件设计及上、下位机软件程序设计,实现了对制动电子控制装置性能的检测。制动测试装置输出控制信号给工控机,接收信号处理单元采集的外部待测试设备脉冲信号。运行在工控机的上位机软件,负责人机交互。根据测试规程要求,对制动电子控制装置进行一系列自动测试,对测试结果评判后生成测试记录文件,成功实现对列车制动系统性能的现场测试。结果表明,该装置准确、可靠,具有重要的应用价值。     

基于测试需求的互操作性测试用例生成方法

网络化应用将成为未来软件技术发展的主导模式。为了保证网络化应用之间能够有效地协同工作,必须对其进行互操作性测试。互操作性测试具有测试需求复杂易变、测试用例设计困难的特点,因而需要消耗大量成本。为此,提出一种基于测试需求的互操作性测试用例生成方法。该方法采用模型驱动的测试思想,以测试需求模型描述互操作性测试需求,以状态图描述各被测应用的规格说明,通过两者的结合生成满足测试需求的测试用例。     

A closed-loop data based test for robust performance improvement in iterative identification and control redesigns

In robust iterative identification and control redesign techniques, a stabilizing controller connected in a closed loop is normally replaced by an alternative attractive stabilizing controller to improve robustness and performance of the closed-loop system. In this paper, novel test methods are proposed to check whether a new stabilizing controller improves performance or not when the existing controller is replaced by this new controller in the closed loop. The proposed tests are based on closed-loop data and no plant model, and can be used for both the SISO and MIMO linear time-invariant systems. For the proposed tests, the plant dynamics is assumed to be unknown whereas the existing and new controller transfer function matrices are known to the designer. These assumptions are common in iterative identification and control redesign techniques. The performance improvement test methods proposed in this paper build on the experimental set-up proposed in Dehghani, Lecchini, Lanzon, and Anderson (2009) which was used to only check whether controllers ensure internal stability of a feedback interconnection or not. In this paper, new test methods are proposed to ascertain robust performance improvement that cannot be obtained from test results of Dehghani et al. (2009). A numerical example is illustrated to show effectiveness of the proposed test methods.     

A new microcomputer-based approach for pilot differential protection of transmission lines

This paper presents a theoretical and experimental study of a new technique for pilot differential protection of transmission lines. The difference currents obtained from post- and pre-fault line currents, adjusted by calculated charging currents, are used to minimize the desensitizing effect of load and line charging currents. The experimental results are from a laboratory 16-bit microcomputer-based relay that was developed to test some of the features of this new approach. Off-line test results for various types of faults on a lumped parameter long transmission line model and real-time test results for a short transmission line model are presented.     

On the use of a similarity function for test case selection in the context of model‐based testing

Test case selection in model‐based testing is discussed focusing on the use of a similarity function. Automatically generated test suites usually have redundant test cases. The reason is that test generation algorithms are usually based on structural coverage criteria that are applied exhaustively. These criteria may not be helpful to detect redundant test cases as well as the suites are usually impractical due to the huge number of test cases that can be generated. Both problems are addressed by applying a similarity function. The idea is to keep in the suite the less similar test cases according to a goal that is defined in terms of the intended size of the test suite. The strategy presented is compared with random selection by considering transition‐based and fault‐based coverage. The results show that, in most of the cases, similarity‐based selection can be more effective than random selection when applied to automatically generated test suites. Copyright © 2009 John Wiley & Sons, Ltd.