多核体系下的并行任务构建

基于多核体系下的系统运行效率越来越受到各行业的关注,一个系统往往是由若干软件子模块构成的.一个完整的系统可以由Tomcat,Httpd以及Lucene这3个软件模块构成.这些软件本身均进行了一定的优化,各自运行效率都良好,可是如果将它们整合成一个系统,其效率的提高仍需要从整体多方面考虑.从不同软件的子任务之间的关系入手,通过分析它们的特点,提出苦干提高整体性能的方案.研究贡献在于以下3个方面:1)线程间同步操作的消除;2)通过多任务重排提高并行度;3)系统调用的单线程化.结果表明系统整体性能得到了提高,同时,每个子任务完成的功能更加清晰明了.     

红霉素肟贝克曼重排反应中的构型异构化

碱性条件下红霉素肟容易由E构型转化为Z构型从而达到平衡。但发现同样是在碱性条件下的贝克曼重排反应后,E构型产物的质量分数相对于原料中E肟的质量分数而言提高了,而Z构型产物的质量分数相应降低了,说明在贝克曼重排反应过程中Z构型异构化为了E构型。该异构化现象的发现为控制阿奇霉素生产条件,从而降低产物中由红霉素Z肟重排得到的副产物的质量分数,提高最终产品阿奇霉素的产率提供了参考,对异构化机理也进行了探讨。     

基于抽象语法树的代码味道识别工具的分析与设计

介绍了如何利用面向对象软件度量方法来识别代码味道,同时提出了以抽象语法树为中间表示形式来设计面向自动化重构的代码味道识别工具,并介绍了该识别工具各个模块的功能与特点.     

基于兴趣区域的图像检索方法的研究

目前大多数基于内容的图像检索(CBIR)技术都依赖于图像的全局特征(例如颜色、纹理直方图等)，这样图像的空间布局特征被忽略了。由此提出的图像检索方法克服了这个问题，它是基于如下原则：用户应最有资格指定查询”内容”，而不是计算机，该方法使得用户能够选择多个”感兴趣区域”并且在检索过程中指定它们的空间布局相关性。     

高速网络环境下内容审计系统的研究与实现

The paper presents a content audit system on high speed network. A new algorithm is provided for load balancing and data distribution which is based on application protocol and session states. A fast text searching approach is also introduced for string matching which includes chars and chinese characters.     

面向对象软件度量技术

提出了OO度量评价规则和标识一组OO度量套件的方法，一组切实可行的OO度量套件及其形式化描述方法，评价OO关键概念和结构特性。质量度量模型是软件质量评价体系中的关键技术，采用层次结构的度量模型。通过质量度量模型，就建立了软件内部属性和外部属性间的客观的定量的联系。OO软件度量框架用以规范化地帮助评测软件产品质量的过程。     

Cultivation and engineering of a software metrics program

Abstract. This paper reports from a case study of an organization that implements a software metrics program to measure the effects of its improvement efforts. The program measures key indicators of all completed projects and summarizes progress information in a quarterly management report. The implementation turns out to be long and complex, as the organization is confronted with dilemmas based on contradictory demands and value conflicts. The process is interpreted as a combination of a rational engineering process in which a metrics program is constructed and put into use, and an evolutionary cultivation process in which basic values of the software organization are confronted and transformed. The analysis exemplifies the difficulties and challenges that software organizations face when bringing known principles for software metrics programs into practical use. The article discusses the insights gained from the case in six lessons that may be used by Software Process Improvement managers in implementing a successful metrics program.     

Software Process and Product Improvement: A Historical Perspective

In this paper, a historical overview of significant attempts to get over the software crisis is presented. In particular, we trace the development of lifecycle models and information systems development methodologies during the last four decades. Finally, we explore the role of measurements and outline current and future works leading to process and product improvement.     

Analogy-Based Practical Classification Rules for Software Quality Estimation

Software metrics-based quality estimation models can be effective tools for identifying which modules are likely to be fault-prone or not fault-prone. The use of such models prior to system deployment can considerably reduce the likelihood of faults discovered during operations, hence improving system reliability. A software quality classification model is calibrated using metrics from a past release or similar project, and is then applied to modules currently under development. Subsequently, a timely prediction of which modules are likely to have faults can be obtained. However, software quality classification models used in practice may not provide a useful balance between the two misclassification rates, especially when there are very few faulty modules in the system being modeled.This paper presents, in the context of case-based reasoning, two practical classification rules that allow appropriate emphasis on each type of misclassification as per the project requirements. The suggested techniques are especially useful for high-assurance systems where faulty modules are rare. The proposed generalized classification methods emphasize on the costs of misclassifications, and the unbalanced distribution of the faulty program modules. We illustrate the proposed techniques with a case study that consists of software measurements and fault data collected over multiple releases of a large-scale legacy telecommunication system. In addition to investigating the two classification methods, a brief relative comparison of the techniques is also presented. It is indicated that the level of classification accuracy and model-robustness observed for the case study would be beneficial in achieving high software reliability of its subsequent system releases. Similar observations are made from our empirical studies with other case studies.     

基于特征串的大规模中文网页快速去重算法研究

网页检索结果中,用户经常会得到内容相同的冗余页面,其中大量是由于网站之间的转载造成。它们不但浪费了存储资源,并给用户的检索带来诸多不便。本文依据冗余网页的特点引入模糊匹配的思想,利用网页文本的内容、结构信息,提出了基于特征串的中文网页的快速去重算法,同时对算法进行了优化处理。实验结果表明该算法是有效的,大规模开放测试的重复网页召回率达97.3% ,去重正确率达99.5%。