高性能的异步复制系统的设计

为了提高整个远程复制系统的性能,对卷复制系统进行了优化.采用了多线程并行处理技术和流水线技术,设计了一种高性能的日志和位图,采用了网络自适应的复制协议和高效的请求合并策略.实验结果表明,该优化策略减少了应用等待的时间,降低了网络发送的时间开销,合理利用了有限的复制带宽,提高了复制效率.     

基于Oracle的邮件系统的存储优化

本文分析了Oracle中大对象(LOB)的存储机理,探讨了LOB字段存储参数的正确配置,提供了多种监控方法,对基于Oracle的邮件系统进行了优化,使数据库存储空间的分配更加合理,提高了系统性能.     

基于SnmpSharpNet的网络管理系统的研究

简单分析了SNMP协议,介绍了SNMP编程原理,构造了一个基于B/S架构的网管系统模型,结合C#编写的SNMP开发包SnmpSharpNet,运用流行的WEB技术,给出了一个网络管理系统实现的基本方法。     

实现可管理的安全--基于风险管理的电力系统安全监控中心的研究

本文简要介绍了风险管理的方法,描述了基于风险管理电力系统安全监控中心的组成部分,讨论了其三级应急响应流程。该监控中心以资产为基础,对安全事件进行了关联分析,能快速准确地定位故障,提高了安全防护体系的效率,实现了可管理的安全。     

基于Labview的发电机组监控系统的设计

综合运用计算机测控技术和检测技术,设计了基于Labview的发电机组的监控系统,介绍了该系统的工作原理、硬件、软件构成及实现方法.该系统利用Labview作为上位机监控软件,采用PLC可编程控制器对现场进行控制,通过OPC接口实现了设备的数据通信,降低了系统开发难度,缩短了开发周期,简化了开发过程.该系统达到了精确、可靠控制的目的.     

基于认证的产生式系统模型的研究

文中在描述了认证和产生式系统的重要性之后,对通常用于专家系统的产生式系统组织进行了叙述。根据用于认证的产生式系统的特殊性,建立了其模型图,叙述了工作原理,讨论该产生式系统的组成。最后,解释了其安全性能。     

树的数据结构的改进研究

本文首先简单介绍了树的原理,然后在分析目录树的基础上给出了一种改进后的树存储数据结构,它在维护大量数据的同时,降低了数据冗余度。在建立树的经典数据结构的基础上提出了一种基于哈希算法的树构建数据结构。通过分析它们的时间复杂度,均较改进前有了较大减少。     

基于SNMP的网络拓扑算法的研究

介绍了在SNMP协议支持下网络的拓扑发现方法,用Java语言定义了数据结构,设计了一种网络拓扑算法,并对该算法进行了分析.     

基于ASP的电子商务系统的研究

电子商务系统改变了当前社会的交易模式,使传统的商业模式转移到互联网上,提高了买卖双方的效率.文章首先对电子商务系统的需求进行了详细分析,其次从功能和数据库两方面对系统进行了设计,最后给出了系统的部分实现.对软件开发人员和电子商务服务人员都具有一定的积极意义.     

基于内容的图像检索系统的最新进展

该文在分析现有的基于内容的图像检索系统结构的基础上,探讨了系统中的关键技术和当前主要优化方法,介绍了目前的系统应用情况,着重归纳了图像检索系统研究的最新进展,并详细阐明了当前研究中存在的问题,最后指出了今后进一步研究的方向。     

基于UML描述的“4＋1”视图模型及应用

由于软件体系结构的描述方法多种多样,各种工具不仅涉及不同领域,而且描述方法不尽相同,给系统选择一种合适工具描述体系结构带来了难度。统一建模语言The Unified Modeling Language（UML）是一种被广泛采纳的可视化建模语言,它对系统结构的共同特征用相关语义、符号、图形加以描述。本文以UML描述为基础,建立软件体系结构“4 1”视图模型,从系统的多个视图描述软件体系结构出发以后提高软件开发效率、平均软件质量与开发周期的矛盾。本文结合“4 1”视图模型给出“综合报警系统”在ROSE2000中的部分实现过程。     

“UML软件建模”的课程教学改革实践

针对传统教学模式在"UML软件建模"课程教学中遇到的问题,本文在"项目驱动法"的基础上,提出了一种基于"翻转课堂"的新型教学模式:该教学方法围绕软件工程中的具体的软件设计案例,强调在线教学平台的设计与使用,强调课前学习,强调课上的在教师引导下的分组讨论。实践表明,该教学方法大大提高了学生的学习主动性和参与意识,有效地解决了该课程因的高综合性和概念抽象性而容易导致学生学习困难的问题。     

基于UML的“4+1”视图软件体系结构描述研究

提出一种基于统一建模语言(UML),用"4+1"的视图模型来描述一个具体系统的体系结构。这种方法包括逻辑视图、教程视图、开发视图和物理视图四种视图,以及场景。通过对一个实例系统的描述,表明这是一个有效而且实用的方法,这种方法涵括了不同的干系人(或者成为"客户")从不同角度所关心的主要的系统结构。     

嵌入式建模中带有时间扩展的UML状态图的形式化方法

面向对象建模语言UML(Unified Modeling Language)已广泛用于嵌入式系统建模,但它在嵌入式实时系统建模时存在概念模型形式化复杂和状态图对时间约束方面的建模功能不强的问题,针对这些问题,提出一种对UML状态图进行时间扩展的方法,并提出利用"可执行UML"对带有时间扩展的UML状态图形式化的方法.     

Leveraging annotation-based modeling with <Emphasis Type="SmallCaps">Jump</Emphasis>

The capability of UML profiles to serve as annotation mechanism has been recognized in both research and industry. Today’s modeling tools offer profiles specific to platforms, such as Java, as they facilitate model-based engineering approaches. However, considering the large number of possible annotations in Java, manually developing the corresponding profiles would only be achievable by huge development and maintenance efforts. Thus, leveraging annotation-based modeling requires an automated approach capable of generating platform-specific profiles from Java libraries. To address this challenge, we present the fully automated transformation chain realized by Jump, thereby continuing existing mapping efforts between Java and UML by emphasizing on annotations and profiles. The evaluation of Jump shows that it scales for large Java libraries and generates profiles of equal or even improved quality compared to profiles currently used in practice. Furthermore, we demonstrate the practical value of Jump by contributing profiles that facilitate reverse engineering and forward engineering processes for the Java platform by applying it to a modernization scenario.     

Towards an ontology-based retrieval of UML Class Diagrams

Context

Software Reuse has always been an important area amongst software companies in order to increase their productivity and the quality of their products, but code reuse is not the only answer for this. Nowadays, reuse techniques proposals include software designs or even software specifications. Therefore, this research focuses on software design, specifically on UML Class Diagrams. A semantic technology has been applied to facilitate the retrieval process for an effective reuse.

Objective

This research proposes an ontology-based retrieval technique by semantic similarity in order to support effective retrieval process for UML Class Diagrams. Since UML Class Diagrams are a de facto standard in the design stages of a Software Development Process, a good technique is needed to reuse them, i.e. reusing during the design stage instead of just the coding stages.

Method

An application ontology modeled using UML specifications was designed to compare UML Class Diagram element types. To measure their similarity, a survey was conducted amongst UML experts. Query expansion was improved by a domain ontology supporting the retrieval phase. The calculus of minimal distances in ontologies was solved using a shortest path algorithm.

Results

The case study shows the domain ontology importance in the UML Class Diagram retrieval process as well as the importance of an element type expansion method, such as an application ontology. A correlation between the query complexity and retrieved elements has been identified, by analyzing results. Finally, a positive Return of Investment (ROI) was estimated using Poulin’s Model.

Conclusion

Because Software Reuse has not to be limited to the coding stage, approaches to reuse design stage must be developed, i.e. UML Class Diagrams reuse. This approach proposes a technique for UML Class Diagrams retrieval, which is one important step towards reuse. Semantic technology combined with information retrieval improves the retrieval results.     

一种DEVS原子模型向UML状态图映射方法研究

离散事件仿真规范DEVS形式化的一个重要不足在于它缺乏一种标准的、图形化的描述形式。该文研究提出了一种将DEVS的原子模型与复合模型分别映射到UML的状态图和组件图的方法,并用形式化的数学方法对DEVS原子模型向UML状态图的映射过程进行了描述与构造。这种映射将DEVS规范融入到了UML的描述形式当中,将DEVS的抽象化描述与UML的表示能力、计算机处理能力结合起来,为两种建模形式的统一提供了一个可行的思路。该文研究的成果在C^4ISR系统总体方案规范化建模中得到了逐步的应用。     

Meaningful modeling: what's the semantics of "semantics"?

The Unified Modeling Language (UML) is a complex collection of mostly diagrammatic notations for software modeling, and its standardization has prompted an animated discussion about UML's semantics and how to represent it. We have thus set out to clarify some of the notions involved in defining modeling languages, with an eye toward the particular difficulties arising in defining UML. We are primarily interested in distinguishing a language's notation, or syntax, from its meaning, or semantics, as well as recognizing the differences between variants of syntax and semantics in their nature, purpose, style, and use.     

Scenario-based verification in presence of variability using a synchronous approach

This paper presents a new model of scenarios, dedicated to the specification and verification of system be- haviours in the context of software product lines （SPL）. We draw our inspiration from some techniques that are mostly used in the hardware community, and we show how they could be applied to the verification of software components. We point out the benefits of synchronous languages and mod- els to bridge the gap between both worlds.     

A cognitive semantics for the association construct

The unified modelling language (UML), besides its traditional use in describing software artifacts, is increasingly being used for conceptual modelling, the activity of describing an application domain. For models to be clear and unambiguous, every construct of the modelling language must have well-defined semantics, which is its mapping to elements of the semantic domain. When used for conceptual modelling, the semantic domain of UML is the application domain, as perceived by the modeller. Modellers perceive and structure their perceptions using cognitive concepts. This paper proposes a mapping of the UML association construct to those concepts. Implications for the use of the association construct for conceptual modelling are derived, a UML profile for conceptual modelling is presented, along with the results of a case study using the semantics and profile.