基于天牛须搜索的软件测试数据扩增方法

为使原测试用例集满足软件演化后新版本程序的测试需求,提出一种基于天牛须搜索算法的软件测试数据扩增方法。静态分析新旧版本程序,获取调用图和程序执行信息并得到所需测试的目标方法集,通过计算目标方法包含错误的影响度获得有序目标方法集。根据原测试用例集的覆盖信息选取部分测试用例作为初始的进化种群,基于分支距离和分支嵌套深度设计适应度函数,采用改进的天牛须搜索算法对有序目标方法集实现测试数据扩增。实验结果表明,与基于遗传算法和粒子群优化算法的测试数据扩增方法相比,该方法的测试数据扩增效率约平均提升49.91%和24.76%,且有效降低了回归测试成本。     

基于自适应粒子群优化算法的测试数据扩增方法

针对在回归测试中原有测试数据集往往难以满足新版本软件测试需求的问题,提出一种基于自适应粒子群算法（APSO）的测试数据扩增方法。首先,根据原有测试数据在新版本程序上的穿越路径与目标路径的相似度,在原有的测试数据集中选择合适的测试数据,作为初始种群的进化个体;然后,利用初始测试数据的穿越路径与目标路径的不同子路径,确定造成两者路径偏离的输入分量;最后,根据路径相似度构建适应度函数,利用APSO操作输入分量,生成新的测试数据。该方法针对四个基准程序与基于遗传算法（GA）和随机法的测试数据扩增方法相比,测试数据扩增效率分别平均提高了约56%和81%。实验结果表明,所提方法在回归测试方面有效地提高了测试数据扩增的效率,增强了其稳定性。     

基于路径引导的回归测试用例集扩增方法

为了全面测试演化软件,回归测试通常需要生成新的测试用例。concolic测试是一种沿着具体执行路径进行符号执行的软件验证技术,通过生成测试数据来执行程序的所有可行路径。回归测试中,由于concolic测试关注于程序本身,没有利用已有测试用例和软件演化信息,导致生成大量无效测试数据,浪费资源和时间。为解决此问题,提出一种基于路径引导的回归测试用例集扩增方法。该方法将目标路径作为引导,根据软件演化信息选择有利于覆盖目标路径的测试用例,利用已有测试用例跳过重叠初始子路径,对后续目标子路径进行concolic测试并生成覆盖目标路径的测试数据。案例分析表明,本文方法相比传统concolic测试,本方法在覆盖程序可行路径的同时,可有效减少concolic测试路径,提高测试数据生成效率。     

基于分支覆盖的回归测试路径选择

回归测试是迭代式软件开发的重要环节,测试数据生成是回归测试的前提.传统的回归测试方法,从已有的测试数据中选择部分测试数据,并生成一些新的测试数据,以验证程序的正确性.但是,该方法容易生成冗余的测试数据,从而降低了回归测试的效率.研究了回归测试的分支覆盖问题,通过利用已有测试数据的路径覆盖信息,并选择一定个数的路径,以覆盖所有的目标分支.首先,以若干路径形成的集合作为决策变量,以路径最少、覆盖的分支最多以及包含的未覆盖路径最少为目标,建立路径选择问题的3目标优化模型;然后,采用遗传算法求解上述模型时,设计了基于目标重要性的个体评价策略;最后,基于已有的测试数据与选择的路径之间的覆盖关系,确定需要生成的测试数据.将所提方法应用于6个基准工业程序测试中,并与其他方法比较.实验结果表明,采用该方法选择的路径,能够覆盖更多的分支,需要生成的测试数据更少,回归测试消耗的时间更短.     

回归测试数据进化生成

采用遗传算法生成回归测试数据近年来得到普遍关注,该方法高效生成测试数据的前提是合理利用已有的测试数据形成初始进化种群,并设计有针对性的遗传操作.但是,到目前为止,相关的研究成果尚不多见.文中研究采用遗传算法生成回归测试数据以覆盖目标路径时,已有测试数据的利用问题,提出一种新的回归测试数据进化生成方法.该方法根据已有测试数据穿越的路径与目标路径的相似度,选择合适的测试数据,作为初始进化种群的部分个体.进一步,根据已有测试数据穿越的路径与目标路径不相同子路径的节点对应的输入分量,确定对进化个体实施遗传操作的位置.理论分析表明,所提方法可以有效提高测试数据生成效率.将所提方法应用于典型基准和工业程序的测试,并与已有方法比较,实验结果证实了所提方法的优越性.     

融合变异测试的路径覆盖测试数据进化生成方法

针对检测缺陷的测试数据生成效率低下问题,提出变异测试和路径覆盖测试技术结合的测试数据生成方法。首先,采用变异测试技术生成的变异分支融入程序,生成新的被测程序;然后,在原路径集中挑选目标路径,通过分析变异分支与路径关联关系,将变异分支融入路径。最后,基于遗传算法生成覆盖路径的测试数据。实验结果表明,多种群遗传算法生成测试数据的时间,比单种群遗传算法节约了41.15%。由此可见,对于覆盖多路径测试数据生成,多种群遗传算法的效率比单种群遗传算法高。     

基于维持种群多样性的测试数据生成算法的研究

测试数据自动化生成技术尝试寻找一个相对小的数据集来满足测试充分性标准,以降低软件测试的成本,提高测试效率.当测试项的数据集大小超过其上限时,算法会使用淘汰算法把差异性较小的测试数据从集合中淘汰掉,把差异性较大的测试数据留下来,以维持种群的多样性.针对此问题,提出一种基于维持种群多样性的演化算法来求解测试数据集,算法利用启发信息迭代地选择一个条件?判定语句作为子目标,通过演化算法生成数据以覆盖目标.在此算法框架内,利用一种新的计算评估值的方法计算数据与测试项的距离信息;以及利用归一的曼哈顿距离计算测试数据差异性,通过淘汰策略把差异性较小的测试数据淘汰掉.在实验中,对14个计算机科学基础算法的基准函数进行了测试,并与现有文献中的测试数据生成方法进行对比,验证了算法有效提高了条件?判定覆盖率,并且减少了测试数据的生成数量,提高了测试性能.     

一种新的数据流覆盖测试数据进化生成方法

数据流覆盖可有效地检测软件中的缺陷与错误.针对该覆盖准则中存在的插装监测开销庞大和测试数据生成效率不高的问题,提出一种新的基于定值-引用对覆盖的测试数据进化生成方法.该方法主要分为两部分,首先,通过约减测试目标来减少插装开销,提出的包含关系算法可找到一个定值—引用对子集,使得覆盖该子集就能保证所有测试目标被覆盖;然后,采用遗传算法为所有测试目标生成测试数据,设计的适应度函数综合考虑个体实际执行的路径与每个测试目标的定义明确路径的匹配程度.将该方法用于8个基准程序的测试数据生成,并与其他方法比较,结果显示其可有效提高程序覆盖率和测试数据生成效率.     

基于变异粒子群算法的字符串型测试数据生成

基于搜索的算法在以路径覆盖为目标的测试数据生成中应用广泛。然而对于字符串型测试数据的生成,现有方法效率不高。为了高效地生成字符串型测试数据,提出了一种基于变异粒子群算法的字符串型测试数据自动生成方法。在随机生成初始种群后,采用粒子群算法使种群在趋近最优个体的过程中实现进化,并以一定的概率对种群中的个体进行变异操作,以避免进化过程陷入局部最优。为了有效地指导种群进化过程,对经典适应度函数中分支距离的计算方法进行改进,使其适用于含有字符串型参数的程序。实验结果表明,该方法具有较高的成功率和稳定性,且能明显提升测试数据生成效率。     

基于复杂系统遗传算法的多路径覆盖测试用例生成方法

针对目前复杂系统多路径覆盖测试用例生成方法较少的问题,提出一种新的基于复杂系统的多路径覆盖测试用例生成方法。首先改进遗传算法,在种群进化中对父代选择、个体进化的学习能力和种群的自适应更新方法进行改进,以有效避免算法收敛过慢或者"早熟"现象。然后根据多路径覆盖测试的特点与要求,设计基于路径匹配的适应度函数,使得运行一次算法便可生成覆盖多条目标路径的多个测试用例。最后将该方法用于几个基准程序。实验结果表明,与已有方法比较,此方法的测试用例生成效率显著提高。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.