基于语法和语义结合的源代码精确搜索方法

针对在编写软件、复用源代码的过程中仅依靠关键词无法精准搜索到适用源代码的问题,提出一种将语法和语义结合的源代码精准搜索方法。首先依据源代码语法语义的客观和唯一性,增加语法结构和\"输入/输出\"语义作为用户录入请求的一部分,并规范了具体的请求格式;然后在此基础上分别设计源代码语法匹配算法、\"输入/输出\"语义匹配算法、关键词兼容匹配,以及源代码搜索结果可信度计算算法;最后综合上述算法实现对源代码的精准搜索。测试结果表明：与单纯的关键词搜索相比,提出的方法对搜索的平均排序倒数（MRR）有超过62%的提升,有助于实现源代码的精准搜索。     

语义搜索：下一代搜索技术？

在目前的互联网应用中,搜索引擎肯定是排名前列的应用之一,几乎每一个上网的人都会使用搜索引擎。因此,围绕搜索引擎形成了一个贯穿行业上下游的产业链。而随着技术的发展,传统的关键词搜索已经逐渐不能满足人们的使用,于是,新一代的搜索技术——语义搜索开始被人们重视起来。     

基于语法与语义分析的代码搜索结果优化

通过示例代码学习简单算法的实现和具体API的使用方式是程序开发人员在软件开发中进行软件复用的高效手段,也是使用代码搜索引擎的主要目的.代码搜索引擎从网页搜索技术发展而来,提供对网络上源代码资源的检索功能,能够有效定位与搜索内容相关的代码,为程序开发人员提供帮助.但现有的代码搜索引擎没有在搜索结果中区别API的实现代码与使用代码,搜索结果存在冗余,导致用户无法快速有效地找到提供有用信息的代码片段.为了使用户更好更快地找到代码搜索目标,阐述了应用语法与语义分析技术从区分API实现代码和使用代码、相似代码聚类、搜索结果摘要3个方面对代码搜索结果进行优化的方法,给出了一个代码搜索引擎的实现,并在实例研究中展示了该方法的有效性.     

基于本体的语义搜索研究综述

基于本体的语义搜索将Web搜索带入一个新时代。它使我们能够在浩瀚的网页中更加快速准确地找到想要的信息。本体具有明确的概念描述,基于本体的搜索能够评测关键词之间的语义差异,从而在文档或者查询中找到更准确的结果。因为所选本体的不同,基于本体的语义搜索方法也会不同。该文总结了多种不同的研究方法,并根据搜索相关技术的分类标准进行了比较。最后通过这些比较,找到今后进一步研究的方向。     

一种语义增强的空间关键词搜索方法

空间关键词搜索立足于查找满足用户查询意图且空间距离相近的兴趣点(point of interest, POI),在地图搜索等领域有着广泛的应用.传统的空间关键词搜索方法仅考虑关键词与POI点在文本上的匹配程度,忽略了查询的语义信息,因而会导致相关结果丢失以及无关结果引入等问题.针对传统方法的局限,提出了语义增强的空间关键词搜索方法S3(semantic-enhanced spatial keyword search).该方法对查询关键词中包含的语义信息进行分析,并结合语义相关性和空间距离对POI点进行有效的排序.S3方法主要有以下2个技术挑战：1)如何对语义信息进行分析.为此,S3引入了知识库对POI数据进行语义扩充,并提出了一种基于图的语义距离度量方式.结合语义距离和空间距离,S3给出POI点的综合排序方案.2)如何在大规模数据上即时地返回top-k搜索结果.针对这一挑战,提出了一种新型的语义-空间混合索引结构GRTree(graph rectangle tree),并研究了有效的剪枝策略.在大规模真实数据集上的实验表明,S3不仅能够返回更为相关的结果,而且有着很好的效率和可扩展性.     

基于开源软件的软件工程实施系统研究

文章介绍了开源软件对软件工程实施各阶段提供的支持,并根据软件工程实施的实际需求,建立了一个基于开源软件的软件工程实施系统.系统采用了基于SOA模式的系统架构,并采用XML中间件实现异构数据的集成.     

复杂语义可搜索加密研究

可搜索加密是一种支持用户在密文上进行关键词检索的密码学原语,能够为用户节省大量的网络和计算开销.进一步地,复杂语义可搜索加密,主要包括通配符可搜索加密、模糊关键词可搜索加密和多关键词可搜索加密,能够支持用户对密文进行各种形式多样化的搜索,而不局限于完整的单关键词搜索,更切合用户的实际搜索情形.本文主要从上述三类复杂语义可搜索加密的研究现状、典型构造、三者关系等方面展开研究,提出一种新的关键词特征提取方式,使得通配符可搜索加密可转化为一般的多关键词可搜索加密,最后讨论了现阶段复杂语义可搜索加密需要解决的问题及未来的研究思路.     

对垂直搜索技术的分析

垂直搜索是针对某一个行业的专业搜索引擎,是搜索引擎的细分和延伸,是对网页库中的某类专门的信息进行一次整合．定向分字段抽取出需要的数据进行处理后再以某种形式返回给用户。相对通用搜索引擎的信息量大、查询不准确、深度不够等提出来的新的搜索引擎服务模式。通过针对某一特定领域、某一特定人群或某一特定需求提供的有一定价值的信息和相关服务。     

基于Petri网可达分析的代码搜索方法

复用已有高质量源代码可提高软件开发效率及软件质量.当前,基于用户提供的输入/输出对的匹配判断是代码语义搜索的主要方法之一,但该方法难以刻画完整代码行为,且仅能处理单输入类型.提出一种针对多种形式类型匹配的代码语义搜索方法.首先将代码集内各个代码片段中数据对象个数及类型的加工过程转换为Petri网模型;其次根据用户查询中...     

触摸语义搜索的脉搏

以关键词为主的第二代搜索逐渐暴露出它的软肋,那么,以基于语义搜索为特征的第三代搜索,是否将迎来属于它的春天？     

Reliability analysis and optimal version-updating for open source software

Context

Although reliability is a major concern of most open source projects, research on this problem has attracted attention only recently. In addition, the optimal version-dating for open source software considering its special properties is not yet discussed.

Objective

In this paper, the reliability analysis and optimal version-updating for open source software are studied.

Method

A modified non-homogeneous Poisson process model is developed for open source software reliability modeling and analysis. Based on this model, optimal version-updating for open source software is investigated as well. In the decision process, the rapid release strategy and the level of reliability are the two most important factors. However, they are essentially contradicting with each other. In order to consider these two conflicting factors simultaneously, a new decision model based on multi-attribute utility theory is proposed.

Results

Our models are tested on the real world data sets from two famous open source projects: Apache and GNOME. It is found that traditional software reliability models provide overestimations of the reliability of open source software. In addition, the proposed decision model can help management to make a rational decision on the optimal version-updating for open source software.

Conclusion

Empirical results reveal that the proposed model for open source software reliability can describe the failure process more accurately. Furthermore, it can be seen that the proposed decision model can assist management to appropriately determine the optimal version-update time for open source software.     

Empirical analysis of search based algorithms to identify change prone classes of open source software

There are numerous reasons leading to change in software such as changing requirements, changing technology, increasing customer demands, fixing of defects etc. Thus, identifying and analyzing the change-prone classes of the software during software evolution is gaining wide importance in the field of software engineering. This would help software developers to judiciously allocate the resources used for testing and maintenance. Software metrics can be used for constructing various classification models which can be used for timely identification of change prone classes. Search based algorithms which form a subset of machine learning algorithms can be utilized for constructing prediction models to identify change prone classes of software. Search based algorithms use a fitness function to find the best optimal solution among all the possible solutions. In this work, we analyze the effectiveness of hybridized search based algorithms for change prediction. In other words, the aim of this work is to find whether search based algorithms are capable for accurate model construction to predict change prone classes. We have also constructed models using machine learning techniques and compared the performance of these models with the models constructed using Search Based Algorithms. The validation is carried out on two open source Apache projects, Rave and Commons Math. The results prove the effectiveness of hybridized search based algorithms in predicting change prone classes of software. Thus, they can be utilized by the software developers to produce an efficient and better developed software.     

化学信息学与开源软件

化学信息学研究需要性能强大而又能随时修订的、开放性的软件工具。通过回顾自由软件到开源软件的发展历史,展示开源式程序开发的丰富成就,包括操作系统如Linux、社区如SourceForge和我国的共创软件联盟等,澄清与copyright针锋相对的copyleft式版权概念,介绍并比较多种软件许可证,对开源软件的发展机制进行简要分析,认为开源软件是满足化学信息学要求的最佳选择。     

Runtime analysis of search heuristics on software engineering problems

Many software engineering tasks can potentially be automated using search heuristics. However, much work is needed in designing and evaluating search heuristics before this approach can be routinely applied to a software engineering problem. Experimental methodology should be complemented with theoretical analysis to achieve this goal. Recently, there have been significant theoretical advances in the runtime analysis of evolutionary algorithms (EAs) and other search heuristics in other problem domains. We suggest that these methods could be transferred and adapted to gain insight into the behaviour of search heuristics on software engineering problems while automating software engineering.     

Organizational adoption of open source software

Organizations and individuals can use open source software (OSS) for free, they can study its internal workings, and they can even fix it or modify it to make it suit their particular needs. These attributes make OSS an enticing technological choice for a company. Unfortunately, because most enterprises view technology as a proprietary differentiating element of their operation, little is known about the extent of OSS adoption in industry and the key drivers behind adoption decisions. In this article we examine factors and behaviors associated with the adoption of OSS and provide empirical findings through data gathered from the US Fortune-1000 companies. The data come from each company's web browsing and serving activities, gathered by sifting through more than 278 million web server log records and analyzing the results of thousands of network probes. We show that the adoption of OSS in large US companies is significant and is increasing over time through a low-churn transition, advancing from applications to platforms. Its adoption is a pragmatic decision influenced by network effects. It is likelier in larger organizations and those with many less productive employees, and is associated with IT and knowledge-intensive work and operating efficiencies.     

User acceptance model of open source software

The development and implementation of open source software (OSS) is one of the most current topics within the academic, business and political environments. Traditionally, research in OSS has focused on identifying individual personal motives for participating in the development of an OSS project, analyzing specific OSS solutions, or the OSS movement, itself. Nevertheless, user acceptance towards this type of technology has received very little attention. For this reason, the main purpose of the current study is to identify the variables and factors that have a direct effect on individual attitude towards OSS adoption. Therefore, we have developed a technological acceptance model on behalf of the users towards a solution based on OSS. For this development, we have considered the technology acceptance model. Findings show that OSS is a viable solution for information management for organizations.     

化学信息学开源软件的集成与复用

软件集成与复用是提高开发效率和质量的重要途径,而开发标准是实现集成与复用的重要因素。通过分析InChI、Jmol和BALL等实例,提出了化学信息学开源软件开发的数据通信标准、界面标准和模块标准问题。在此基础上,以作者进行的分子相似性与差异性研究为例,展示了对开源科学计算软件SciLab的主成分分析(PCA)模块进行改进、集成和复用的情况,说明对开源软件应采取扬弃态度,保障集成、复用的成效。     

In search for a widely applicable and accepted software quality model for software quality engineering

Software Quality Engineering is an emerging discipline that is concerned with improving the approach to software quality. It is important that this discipline be firmly rooted in a quality model satisfying its needs. In order to define the needs of this discipline, the meaning of quality is broadly defined by reviewing the literature on the subject. Software Quality Engineering needs a quality model that is usable throughout the software lifecycle and that it embraces all the perspectives of quality. The goal of this paper is to propose the characteristics of a quality model suitable for such a purpose, through the comparative evaluation of existing quality models and their respective support for Software Quality Engineering.     

The attraction of contributors in free and open source software projects

As firms increasingly sanction an open sourcing strategy, the question of which open source project to undertake remains tentative. The lack of established metrics makes it difficult to formulate such strategy. While many projects have been formed and created, only a few managed to remain active. With the majority of these projects failing, firms need a reliable set of criteria to assess what makes a project appealing not only to developers but also to visitors, users and commercial sponsors. In this paper, we develop a theoretical model to explore the contextual and causal factors of project attractiveness in inducing activities such as source code contribution, software maintenance, and usage. We test our model with data derived from more than 4000 projects spanning 4 years. Our main findings include that projects’ set of conditions such as license restrictiveness and their available resources provide the context that directly influence the amount of work activities observed in the projects. It was also found that indirect and unintended contributions such as recommending software, despite of being non-technical, cannot be ignored for project activeness, diffusion and sustainability. Finally, our analysis provide evidence that higher attractiveness leads to more code-related activities with the downside of slowing down responsiveness to address projects’ tasks, such as the implementation of new features and bug fixes. Our model underscores the significance of the reinforcing effects of attractiveness and work activities in open source projects, giving us the opportunity to discuss strategies to manage common traps such as the liability of newness. We conclude by discussing the applicability of the research model to other user-led initiatives.