面向软件缺陷预测的网络嵌入特征研究

已有研究根据软件的代码依赖、修改历史、协同开发关系等,建立网络模型来预测软件的缺陷;近年来,网络嵌入技术广泛用于软件网络分析,显著提升了缺陷预测效果.本研究发现不同软件关联网络和网络嵌入算法的组合将影响缺陷预测性能.具体地,本文针对3种软件关联网络(类依赖网络、文件耦合网络和开发者贡献网络),并应用6类网络嵌入方法,分...     

复杂软件系统的软件网络结点影响分析

目前一些研究利用复杂网络理论揭示了软件网络的特性,为人们从系统的角度了解软件的结构提供了方法.但这些研究的一些结论却与软件的实际表现有着较大的差异.分析了软件网络结点的特性,揭示了产生上述差距的部分原因;并提出一种加权软件网络模型,以更准确地描述软件网络结点间的依赖关系;在这个加权软件网络模型的基础上,分析了软件的实际依赖关系及几个统计特性;分析了各统计特性与软件网络结点影响的关系;进一步提出了软件网络关键结点的概念;同时,在分析各种结点影响的基础上,提出了4 个合理的假设;最后,通过对两款软件的实验来验证这4 个假设的有效性.     

开源软件供应链安全问题研究

当前,开源已经成为软件开发的重要模式之一。由于开源开发模式具有代码来源多样、依赖关系复杂等特点,使得开源软件面临代码漏洞风险、供应链攻击风险、知识产权风险、可持续维护风险等供应链安全问题,且问题呈现出快速增长态势。本文基于对开源软件供应链中的安全风险分析,提出从开源软件安全漏洞检测、软件成分分析、许可证冲突检测、开源生态可持续治理四个方面进行安全治理的方法,指出构建安全软件供应链面临依赖关系复杂、结构脆弱等挑战,对软件成分分析、供应链构建等未来研究方向进行了展望。     

基于版本间克隆映射的演化模式识别及谱系构建

针对当前克隆谱系的构建方法较为复杂、演化模式亟需扩充等问题,提出了新的克隆代码演化模式,并根据软件版本间的克隆代码映射关系自动构建了克隆谱系。首先,针对软件每一版本进行克隆检测并利用潜在狄利克雷分配（LDA）抽取克隆代码的主题信息;然后,根据克隆代码主题的相似度确定版本间克隆代码的映射关系;进而,根据已有的映射关系为克隆代码添加演化模式并分析演化特征;最终,结合映射信息与演化模式信息完成克隆谱系的构建。针对4款开源软件进行了克隆谱系的构建实验,实验结果表明所提克隆谱系构建方法可行,证实了新提出的演化模式在克隆代码演化过程中确实存在。实验发现约90%的克隆代码在软件演化过程中比较稳定,约67%的克隆群经历的发布版本数不超过发布版本总数的一半。实验结论及理论分析将为克隆代码的后续研究及克隆代码的维护与管理提供有力支持。     

基于分组的代码克隆增量检测方法

代码克隆是指软件程序中一组相同或相近的代码片段,它广泛存在于软件中,因此如何发现代码克隆成为软件维护的一个重要问题。目前已有的克隆检测工具大多针对单一版本进行完整的克隆检测,然而对于大规模、复杂软件系统而言,在软件演化过程中随着代码的改变,不断重新检测代码克隆将花费较高的代价。针对这一问题,提出了一种基于分组的增量克隆检测方法。该方法根据前后两个版本的差异将源代码分为发生变化和未发生变化的两组,通过组内和组间的克隆分析实现增量的克隆检测。基于所提出的方法,在克隆检测工具CCFinderX的基础上实现了一个名为ICDBG（incremental clone detector based on grouping）的原型工具。实验证明,在变更较小时,该方法能够在保证正确性的同时显著减少克隆检测时间。     

代码坏味对软件演化影响的实证研究

代码坏味是指程序设计中存在的不良设计模式或设计缺陷.坏味的存在,被认为会阻碍软件的演化与维护.近年来,研究人员致力于探究坏味产生的影响以及坏味与软件演化之间的关系.已有研究表明,代码坏味会随着软件的演化而不断发生变化.通常,软件的演化将涉及源文件的增加、修改与删除这3类具体操作,了解代码坏味与软件演化中源文件操作的关系,将有助于开发者更好地计划软件开发过程和重构软件代码.因此,针对13种常见的坏味,在8个Java项目共计104个版本中进行了系统的实证研究.研究发现,随着软件版本的演化,含代码坏味的文件在整个项目中的占比在不同的项目中呈现出不同的特征.另外,包含代码坏味的文件更倾向于被修改,而坏味本身与文件的添加或者删除并没有太大的关联.更进一步地,在探究的所有坏味中,有几种特定的坏味对文件的修改产生了显著的影响,且这些坏味文件间存在着明显的重叠.这些发现有助于开发人员更好地了解代码坏味,以便于更好地对软件进行维护.     

版本管理与代码走查系统设计与实现

为优化软件项目管理,解决软件版本管理混乱、人工代码走查过程负责和结果难于控制的问题,研究了软件版本管理工具和代码走查工具,介绍了版本管理工具和代码走查工具在软件项目管理中应用。根据实践中软件项目管理的需求,提供了一种版本管理工具Subversion与代码走查工具Reviewboard相结合的系统的实现方法,介绍了版本管理工具和代码走查工具的安装部署,给出了一种基于该系统的软件开发应用流程。     

结合可达性分析的代码片段推荐

为满足日益复杂的软件需求,开发人员需要通过代码提示工具来辅助完成开发任务,但现有代码提示工具在推荐包含静态方法的代码片段时存在空间爆炸问题。为此,提出一种基于程序环境信息的代码片段推荐方法。结合可达性分析进行推荐能够有效削减静态方法入口点,在避免空间爆炸的同时,还可以准确、有效地描述程序环境信息。基于该方法实现在Eclipse中的代码推荐插件,并对Tomcat源码进行实验验证。实验结果表明,该方法可实现静态方法的代码片段推荐,与Eclipse Code Recommenders插件中的推荐方法相比,能获得更准确的推荐结果。     

软件库依赖图谱的复杂性度量方法及其潜在应用

在软件开发过程中,软件库可以减少开发时间和节约成本而被广泛使用,因此现代软件项目包含多种不同来源的代码而使得系统具有更高的复杂性和多样性.软件库在使用的过程中常常伴随着各种风险,如低质量或安全漏洞,从而严重影响软件项目的质量.通过分析与软件库的耦合强度,来量化由软件库的依赖关系而引入客户代码的复杂性和多样性.首先,根据客户代码与软件库之间方法的调用关系建立软件边界图模型,区分开客户代码和软件库的代码边界;进而基于此提出一套软件库依赖图谱的复杂性度量指标RMS,用以量化不同来源软件之间的耦合强度.在实验过程中,挖掘Apache开源社区中10个流行软件所有历史版本数据,最终收集到7 857个真实项目间依赖缺陷问题.在上述真实数据基础上,结合所提出的复杂性度量指标RMS,利用假设验证方法开展实证调查研究来探讨:H1:风险因子更高的边界节点是否更容易引入更多数量的项目间依赖缺陷; H2:风险因子更高的边界节点会是否更容易引入严重等级高的项目间依赖缺陷; H3:RMS度量指标数值多大程度地影响了引入项目间依赖缺陷数量和严重等级.实验结果表明,根据RMS度量指标评估,与软件库耦合度更高的边界节点容...     

第三方库依赖冲突问题研究综述

软件开发过程中, 开发人员通过大量使用第三方库来实现代码复用. 不同第三方库之间存在依赖关系, 第三方库间的不兼容会导致第三方库的安装、加载、调用时出现错误, 进而导致系统异常, 这类问题称之为第三方库依赖冲突问题. 依赖冲突的根本原因是加载的第三方库无法覆盖软件引用的必需特性(例如: 方法). 依赖冲突问题会在第三方库的下载安装, 项目编译和运行时中出现, 且定位困难. 依赖冲突问题的修复要求开发人员对使用的第三方库版本间差别具有准确的理解, 并且第三方库之间复杂的依赖关系增加了修复难度. 为了能够在软件运行前, 发现软件中存在的依赖冲突, 并且能够响应和处理运行过程中由依赖冲突引发的系统异常, 国内外学者展开了各种针对依赖冲突问题的研究. 从依赖冲突问题的4个方面, 对当前已有研究工作进行了梳理, 包括: 第三方库的使用实证分析、依赖冲突原因分析、依赖冲突检测方法以及依赖冲突常用修复方式. 最后对该领域未来值得关注的研究问题进行了展望.     

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.