XML文档访问控制研究

针对XML文档访问控制过程中,更新操作引起的重复DTD验证以及DOM树解析、标记问题,提出操作类型的概念。根据操作类型区分不同的更新访问请求,过滤掉不具权限的请求,以节省验证以及标记过程所耗费的内存等系统资源。通过实例证明该方法在更新请求频繁的情况下,性能优于现有的访问控制技术。     

一种目标驱动的移动业务流程的分析方法

随着移动互联网的发展,如何改进现有的业务流程来更好地满足用户的需求成为企业普遍面临的问题。然而,对于企业中哪些业务需要移动化以及如何移动化,目前仍然缺乏相应的分析方法。针对该问题,提出一种基于目标的移动业务流程分析方法。该方法认为企业的各个业务流程都是为了满足一定的用户需求,因此提出建立企业业务流程模型与用户需求模型之间的对应关系,然后通过识别移动环境下用户需求的变化来改进企业的业务流程。以一个医院的业务流程为案例说明了所提方法的可行性。     

功能需求到测试用例的可追溯性研究

软件开发主要由需求收集、设计、实现、测试和维护等几个阶段构成,其中维护始终是主要开销。在维护阶段,开发人员必须理解程序才能定位缺陷,而系统的需求和源代码、测试用例等之间的可追溯性连接能帮助减少开发人员在理解程序时的工作量。研究现有的功能定位技术和可追溯性方法,通过对现有方法的改进,提出了一种集成动态执行信息和IR技术的方案来建立需求到测试用例的可追溯性连接,用以辅助开发人员在维护阶段的工作。     

基于DES加解密技术的电子文档访问控制方法

电子文档的在线阅览已经非常普遍.付费用户可以下载文档或在线阅读文档的全部内容,而普通用户则只允许预览有限的内容.通过这种方式可以在一定程度上实现对电子文档使用范围的控制.但该方式的不足在于,付费用户下载文档后,可以随意将下载的文档转发给他人.因而,如何在文档被下载后依然能对其使用范围进行限制,从而更好地实现版权保护,值得研究和摸索.本课题重点研究电子文档的线上线下访问控制方法：通过对注册用户权限的限制实现电子文档的线上访问控制,基于DES加解密等技术控制下载文档的线下使用范围.实验结果表明,本文所提出的基于DES加解密技术的电子文档线上线下访问控制方法,能够更加有效地对电子文档的访问权限进行控制,具有更强的版权保护力度.     

A semantics for Behavior Trees using CSP with specification commands

In this paper we give a formal definition of the requirements translation language Behavior Trees. This language has been used with success in industry to systematically translate large, complex, and often erroneous requirements documents into a structured model of the system. It contains a mixture of state-based manipulations, synchronisation, message passing, and parallel, conditional, and iterative control structures. The formal semantics of a Behavior Tree is given via a translation to a version of Hoare’s process algebra CSP, extended with state-based constructs such as guards and updates, and a message passing facility similar to that used in publish/subscribe protocols. We first provide the extension of CSP and its operational semantics, which preserves the meaning of the original CSP operators, and then the Behavior Tree notation and its translation into the extended version of CSP.     

面向行为的需求建模研究及实现

需求建模是需求工程中的重要步骤。提出了一种面向行为的需求建模方法,首先将目标系统问题域划分成多个子问题域,然后在子问题域里建立多个视点,在每个视点内,根据需求建立多个场景。对于每个场景,用行为描述语言建立场景行为模型,视点内所有场景的行为模型组合构成视点行为模型,目标系统所有视点的行为模型组合构成系统行为模型。在行为模型的基础上,提出了一系列特性以及其验证方法,用于验证行为模型的正确性以及系统特性。基于以上方法,设计和实现了面向行为的需求建模工具BRMT),以辅助开发人员从行为的角度进行需求建模。     

An Experimental Investigation into the Effectiveness of OOA for Specifying Requirements

The application of object oriented concepts (OO) to the requirements phase of information systems (IS) and software development has been adopted by many proponents of IS and software development methodologies. Although many claims have been made about the effectiveness of OO techniques for improving requirements analysis, very few experimental studies have been done to substantiate these claims. This paper addresses this gap in the literature by conducting an experimental study that attempts to validate the effectiveness of object-oriented analysis (OOA) by comparing it to structured analysis (SA) for producing requirements. We argue that the quality of the requirements specification can be measured and that measurement can be used to compare the effectiveness of OOA and SA. We present an overview of the basic models and principles associated with OOA and SA, a discussion of quality in requirements definition, and a detailed discussion of the research methodology used. A review of relevant research is also presented and directions for further research are suggested. Our findings suggest that the OOA methodology does not necessarily produce better requirements statements.     

Linguistic Problems with Requirements and Knowledge Elicitation

Human and conversational aspects of requirements and knowledge identification are employed to show that requirements ‘engineering’ is not the same as civil engineering or scientific problem solving. Not only can requirements not be made fully explicit at the start of a project, they cannot be made fully explicit at all. A need is identified to enhance computer-based information systems (CBIS) development methods to accommodate: plurality of incommensurable perspectives, languages and agendas; dynamic representations of system features that can be experienced rather than abstracted and forced into an abstract paper-based representation; recognition that CBIS development is in general a continuous process where users changing their minds is a natural and necessary indication or organisational vitality.  It is suggested that prototyping and rapid application development go some way to addressing these requirements but that they require further development in the light of the theoretical light thrown on the nature of the problem.     

数据库的图象处理方法

随着电脑应用的深入和普及,在计算机人事信息管理过程中,多媒体信息的处理方法和手段已经成为计算机信息处理的一个热门话题。该文探讨了数据库图像存储、处理以及在程序设计中如何还原和再现的一系列问题,对于学习数据库编程具有非常重要的参考和借鉴意义。     

Model-driven assessment of system dependability

Designers of complex real-time systems need to address dependability requirements early on in the development process. This paper presents a model-based approach that allows developers to analyse the dependability of use cases and to discover more reliable and safe ways of designing the interactions of the system with the environment. The hardware design and the dependability of the hardware to be used also needs to be considered. We use a probabilistic extension of statecharts to formally model the interaction requirements defined in the use cases. The model is then evaluated analytically based on the success and failure probabilities of events. The analysis may lead to further refinement of the use cases by introducing detection and recovery measures to ensure dependable system interaction. A visual modelling environment for our extended statecharts formalism supporting automatic probability analysis has been implemented in AToM³, A Tool for Multi-formalism and Meta-Modelling. Our approach is illustrated with an elevator control system case study.