基于问题框架的视点集成

多视点需求工程方法采用独立、分散的方式标识，表示不同项目人员的需求信息。为生成一份统一的规格说明书，在该方法的后期必须对所有生成的视点进行集成。基于问题框架的思想和方法，该文讨论了视点的一致性、集成方式、集成过程等，提出了一种基于问题框架的视点集成方法。     

基于概念图的多视点需求模型

本文提出了一种以概念图为元表达语言的多视点需求建模方法.该模型提供了一种多视点中不同表示风格带来的问题的解决方法,该方法使用多视点进行需求获取,通过统一建模语言中的协作图简化了视点间的一致性检查,使多视点的集成更为简便.     

基于Viewpoint Agent的新型需求描述模型

需求工程是整个软件工程的关键部分，为了能清晰地得到软件规约，提出了一种新型的需求工程方法——基于多视点的需求代理模型。这个模型结合了多视点方法对分布式环境下的需求描述的能力和Agent的自治能力，从而能在分布式的开发环境下自动地得到软件规约。通过一个实例展示了Viewpoint Agent对基于多视点的需求描述自动进行规约的过程。     

视点间的不一致性检查和视点集成

需求定义人员常从同的观察角度来定义大型软件系统的需求,从而形成多个部分需求说明（视点）。由于视点之间的相对独立性,多视点的集成是需求工程中一项重要而又困难的研究课题。使用形式化方法来描述视点需求和视点间的关系将使视点集成能自动进行。在此,使用SFSM状态转换图来描述视点需求,并将视点间的关系用谓词的形式表示在状态图中状态转换的卫士条件中,同时在此基础上提出了一种自动合成视点的方法,需求定义人员可以根据状态等价关系与合成后状态图的冲突来检查和解决两个视点之间的不一致性。通过重复视点合成和检查、处理视点间的不一致性这一过程,多个视点可以被集成为整个软件系统的需求说明,应用了一个电话系统的例子说明了此视点需求表示和视点集成方法。使用此方法,视点集成过程可以自动完成,同时还可以在一定程度上引导需求定义人员检查和解决视点间的不一致性。     

基于问题域与视点代理的需求工程研究

在当前需求工程中有关多视点的研究基础上，本文提出了视点代理的概念，给出了代理模板的基本结构，并在此基础上简要介绍了关于模型转换及一致性检查等问题。最后给出如何将视点代理和问题域相结合形成新的需求工程开发方法。     

多视点需求工程中视点集成过程的研究

多视点需求工程方法以视点的形式,分散、独立地获取和表示不同项目相关人员的需求信息.为生成一份统一的规格说明,必须对所有相关的视点进行集成.讨论了以公共开发方式作为视点的集成方式,并基于范畴理论对集成过程进行建模.同时,以公共开发的选取为导向,提出了视点集成的两种优化策略,并证明了它们的有效性.此外,讨论了视点集成的结果与集成的顺序之间的关系.     

基于多视点的需求描述模型

本文提出了一个基于多视点的需求描述模型,该模型可通过视点模板来定义用户的需求,此外,本文也结合一个管理信息系统的实例,介绍了使用这一需求描述模型定义软件系统需求的全过程。     

多视点元模型间需求追踪性方法

以全面而统筹的眼光解决问题,则必须从局部分析不同的侧面,面向多视点的需求工程即为该理论的一个应用.多视点需求工程越来越受到重视,但是各视点间却缺少统一,这不仅不利于获取完整的系统需求,还导致需求变更困难等问题.为了解决以上问题,首先提出一个新的多视点建模过程框架,合理的建模框架有利于获取完整的系统需求.其次在多视点建模过程框架下建立追踪元模型,阐明系统需求在多视点元模型间的平稳过渡.最后结合需求追踪矩阵方法在追踪元模型间建立起追踪关系,进而通过计算变化追踪矩阵在需求变更时可以追踪到相关元素并进行更改,解决需求变更困难的问题.     

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。     

多视点中不一致性的处理：一种基于认知逻辑的方法

衡量一个软件系统是否成功,一个基本的要素就是看该软件系统是否满足了用户的要求。软件系统需求工程(RE)就是一个通过标识涉众及其需求并将其文档化以便于进行分析的过程。RE是一个跨学科,以人为中心的过程。多视点需求工程是需求工程的一个分支。多视点需求工程就是希望复杂系统中的不同参与者分别从自己的角度出发对预期系统进行描述,从而形成更完备的需求规约。由于多视点方法的这种特性,导致多个涉众有可能对同一问题进行描述,从而形成重叠的需求。这些重叠的需求就是涉众之间的公共知识,对公共知识的不同解释是导致需求规约中不一致问题的根源。不一致性是多视点需求工程中一个必须解决的问题。本文提出了基于问题域的多视点需求建模框架,并利用认知逻辑对该框架进行解释和推理,希望可以用形式化的方法来发现和解决存在于不同视点间的不一致性。     

Viewpoints: principles, problems and a practical approach to requirements engineering

The paper includes a survey and discussion of viewpoint‐oriented approaches to requirements engineering and a presentation of new work in this area which has been designed with practical application in mind. We describe the benefits of viewpoint‐oriented requirements engineering and describe the strengths and weaknesses of a number of viewpoint‐oriented methods. We discuss the practical problems of introducing viewpoint‐oriented requirements engineering into industrial software engineering practice and why these have prevented the widespread use of existing approaches. We then introduce a new model of viewpoints called Preview. Preview viewpoints are flexible, generic entities which can be used in different ways and in different application domains. We describe the novel characteristics of the Preview viewpoints model and the associated processes of requirements discovery, analysis and negotiation. Finally, we discuss how well this approach addresses some outstanding problems in requirements engineering (RE) and the practical industrial problems of introducing new requirements engineering methods.     

一种基于行为的多视点需求描述方法

传统多视点方法存在着诸多不足之处。本文在此基础上提出了一种基于行为的多视点需求描述方法（BVORA）,从行为的角度对需求进行了描述,提出了以场景对视点进行划分的方法,给出了视点的定义以及视点表达,定义了视点间的关系。     

场景与视点结合的需求获取方法及应用分析

需求获取是软件开发的一个重要环节。文章对现有的几种主流的需求获取方法进行了归纳分析,提出了一种将场景和视点结合的需求获取方法。利用该方法能够采集到系统的需求并将其描述清晰。通过一个实例验证了该方法的有效性。     

Formal Analysis of Memory Requirements

Shared memory provides a convenient programming model for parallel applications. However, such a model is provided on physically distributed memory systems at the expense of efficiency of execution of the applications. For this reason, applications can give minimum consistency requirements on the memory system, thus allowing alternatives to the shared memory model to be used which exploit the underlying machine more efficiently. To be effective, these requirements need to be specified in a precise way and to be amenable to formal analysis. Most approaches to formally specifying consistency conditions on memory systems have been from the viewpoint of the machine rather than from the application domain.  In this paper we show how requirements on memory systems can be given from the viewpoint of the application domain formally in a first-order theory MemReq, to improve the requirements engineering process for such systems. We show the general use of MemReq in expressing major classes of requirements for memory systems and conduct a case study of the use of MemReq in a real-life parallel system out of which the formalism arose.     

Non-Single Viewpoint Catadioptric Cameras: Geometry and Analysis

Conventional vision systems and algorithms assume the imaging system to have a single viewpoint. However, these imaging systems need not always maintain a single viewpoint. For instance, an incorrectly aligned catadioptric system could cause non-single viewpoints. Moreover, a lot of flexibility in imaging system design can be achieved by relaxing the need for imaging systems to have a single viewpoint. Thus, imaging systems with non-single viewpoints can be designed for specific imaging tasks, or image characteristics such as field of view and resolution. The viewpoint locus of such imaging systems is called a caustic. In this paper, we present an in-depth analysis of caustics of catadioptric cameras with conic reflectors. We use a simple parametric model for both, the reflector and the imaging system, to derive an analytic solution for the caustic surface. This model completely describes the imaging system and provides a map from pixels in the image to their corresponding viewpoints and viewing direction. We use the model to analyze the imaging system's properties such as field of view, resolution and other geometric properties of the caustic itself. In addition, we present a simple technique to calibrate the class of conic catadioptric cameras and estimate their caustics from known camera motion. The analysis and results we present in this paper are general and can be applied to any catadioptric imaging system whose reflector has a parametric form.     

诱导维修中的局部视点优选方法

在诱导维修过程中,为了使维修者能够快速准确地找到待维修目标区域,并提供一个最佳的观察视角来提高对维修目标和场景的认知,需要构建视点规划模型.为此提出一种诱导维修中局部视点的优选方法,在目标区域周围建立候选视点区域,根据约束条件,从目标的可见性、观察质量及视点舒适度几个方面来制定视点评价函数,通过离散寻优的方式进行了视点优选.实验结果表明,应用该方法所选出的最优视点比其他视点观察质量更好,对比结果论证了方法的有效性.     

User viewpoint modelling: understanding and representing user viewpoints during requirements definition

There has been increasing awareness of the impact of the early stages of systems development on the quality of information systems. A critical early activity is requirements definition, when the requirements for an information system are determined. Traditional requirements capture techniques do not support the collaborative nature of requirements definition or the emergent nature of requirements themselves. This paper focuses on viewpoint development as a means of resolving some of the difficulties of requirements definition. It proposes a user viewpoint model for capturing and representing the viewpoints of users during requirements acquisition. The model can facilitate communication and interaction between analysts and users and help build a shared understanding of requirements. It can be used to structure the requirements acquisition process. The model provides for evaluation of requirements acquisition techniques to guide the selection of appropriate techniques for developing user viewpoint models. The paper reports a multiple-case study of requirements definition efforts that examined user viewpoint development in practice and used the cases to validate empirically the concepts of the user viewpoint model. The implications of the case study findings for requirements definition practice are discussed, and some areas for future research are identified.     

基于视点纠正的鱼眼图像场景化漫游方法

针对鱼眼图像畸变大、表示的场景信息不直观等特点,本文提出了一种 基于视点纠正的鱼眼图像场景化漫游方法。该方法以鱼眼图像所表示的半球空间为观察对 象,通过视点的转移在半球空间进行漫游,以对不同区域内的场景信息进行直观的观察。采 用鱼眼图像校正算法为基础建立鱼眼镜头的球面映射模型,通过映射关系对以视点为中心的 观察区域进行实时校正,当视点变化时对校正后的可视区域进行实时显示从而实现漫游。实 验结果表明,通过本文算法能够实现鱼眼图像所表示半球空间的实时漫游,且漫游时显示的 校正图像满足直线约束标准。