面向软件动态演化的需求建模及其模型规范化

针对目前需求工程阶段对软件动态演化考虑不足的现状,在分析软件动态演化面临的挑战的基础上,设计了面向动态演化的需求元模型(dynamic-evolution-orientedrequi rements meta-model,DERM)。该元模型以特征为基本部件,按特征组合的方式建立需求模型,需求模型由行为特征和属性特征组成。行为特征被区分为计算行为特征和交互行为特征,以实现计算和交互的相对隔离;属性特征通过其作用域,指定其在行为特征模型中的作用范围,从而将行为特征模型和属性特征模型统一为需求模型。在此基础上,讨论了需求模型的参照完整性、依赖一致性和互斥一致性,并进一步把需求模型规范化为需求模型第一范式到第三范式,需求模型规范化的过程提供了一种保证需求模型一致性的方法。最后通过案例研究,表明了该方法的可行性及其对软件动态演化的有效支持。     

基于进程代数规约生成软件体系结构模型的方法

需求规约到软件体系结构(SA)模型的转换是软件工程领域的一个研究热点,UML-RT广泛用于实时系统软件体系结构建模,然而基于自然语言规约建立的UML-RT模型往往是不精确的,存在二义性,为了解决这一问题,需要赋予UML-RT模型形式化语义.进程代数是一种用来解决并发系统通信问题的形式化方法,具有精确的语法和语义,并且便于机器自动检验与验证.TCSP是进程代数CSP的实时扩展,适合于规约实时系统带有时间约束的行为.提出一种基于进程代数规约生成SA模型的方法.首先建立了自然语言规约到SA模型的转换框架;然后使用时间通信顺序进程(TCSP)描述实时系统需求规约,通过建立TCSP到UML-RT的转换机制,从而实现进程代数规约到SA模型的转换;最后通过一个实例来验证该方法在实时软件建模过程中的有效性.实验分析表明通过该方法建立的UML-RT模型能够从整体上提高实时系统SA设计的可信性.     

一种软件需求模型到设计模型的转换方法

针对复杂软件开发过程中需求模型到设计模型转换的问题,讨论了在软件设计过程中如何将数据流图转换为结构图。首先,根据软件设计方法提出了从需求模型到设计模型的项目背景。其次,对本项目的需求进行了分析,着重介绍了本项目绘图输入模块的设计方法。最后,描述并给出了实验结果。实验结果表明该文提出的数据流图到结构图的转换方法的正确性和有效性。     

网上电子交易中的谈判协商模型

本文讨论网上交易中买卖双方的谈判协商模型。详细研究了电子商务的谈判协商模型中的商品多属性量化模型和报价函数。提出了进行买卖双方商品需求匹配的距离函数,并讨论了一个为达到利益最大化而得到最佳报价的方法。     

云环境下主客观协同的信任模型研究

近年来云环境的信任问题一直是学术界和工业界讨论的热点问题,也成为阻碍云计算发展的主要因素。为此,提出了基于理想点法(Technique for Order Preference by Similarity to Ideal Solution,TOPSIS)的主客观协同信任模型(SOCTM)。SOCTM提取了主观与客观特征属性,根据主客观特征属性值构建特征矩阵,从而将主观与客观信任结合起来。对于部分用语言术语描述的特征属性值,使用模糊集将其转换为具体的数值。同时,SOCTM使用用户主观赋权重的方法,对于不同特征属性,用户可根据自己的需求,赋予不同的权重,这样最终选择出的云服务提供商(CSP)将更加符合用户需求。TOPSIS被应用到信任值的计算中,根据排序后的计算结果,选出最优的CSP。     

关系模型到ER模型的转换研究

论文结合具体事例,分析了数据库领域内最常用的ER模型和关系模型,并详细介绍了从关系模型到ER模型的转换算法。算法的关键是通过牺牲时间复杂度的代价,遵循特定的转换顺序,将关系数据库中的各种关系以及关系之间的外键属性转换成ER模型中的各种实体与属性。经过研究表明,本文介绍算法对未来的计算机程序进行自动化转换有重要的指导意义。     

基于辩论的多商品谈判模型研究*

旨在对一组商品的多agent谈判进行研究,这组商品具有共同的性质,能满足买方特定需求。通过分析一组商品的属性特征,将商品的属性分为主属性和非主属性,用辩论方法构建多商品谈判机制,提出基于辩论的多商品谈判模型,并通过原型系统实验验证了模型的正确性和有效性。提出的模型将一组商品的多agent谈判统一到一个过程中,有利于达成谈判协议,提高谈判效率。     

非线性NARMAX模型的ARMAX模型全局构造

给出一种复杂的、模型未知的非线性系统的全局线性化方法。该方法用时变的ARMAX模型近似描述一个非线性NARMAX模型。讨论了这一线性化方法的有界性并给出了相应线性化构造方法。仿真结果说明了该线性化方法的有效性。     

Computable Models

We investigate mathematical modelling with theories of datatypes. We provide a formal setting for the formulation of suchtheories (TPL) and use it to introduce the notion of a computationalmodel. We explore the notion and provide several case studies.     

Compact Models

Development of approximation techniques for highly detailed surfaces is one of the challenges faced today. We introduce a new mesh structure that allows dense triangular meshes of arbitrary topology to be approximated. The structure is constructed from the information gathered during a simplification process. Each vertex of the simplified model collects a neighbourhood of input vertices. Then, each neighbourhood is fitted by a set of local surfaces taking into account the sharp features detected. The simplified model plus the parameters of these local surfaces, conveniently stored in a file, is what we call Compact Model (CM). The input model can be approximated from its CM by refining each triangle of the simplified model. The main feature of our approach is that each triangle is refined by blending the local surfaces at its vertices, which can be done independently of the others. Consequently, adaptive reconstructions are possible, local shape deformations can be incorporated and the whole approximation process can be completely parallelized.     

Inflatable Models

A physically-based model is presented for the simulation of a new type of deformable objects-inflatable objects, such as shaped balloons, which consist of pressurized air enclosed by an elastic surface. These objects have properties inherent in both 3D and 2D elastic bodies, as they demonstrate the behaviour of 3D shapes using 2D formulations. As there is no internal structure in them, their behaviour is substantially different from the behaviour of deformable solid objects. We use one of the few available models for deformable surfaces, and enhance it to include the forces of internal and external pressure. These pressure forces may also incorporate buoyancy forces, to allow objects filled with a low density gas to float in denser media. The obtained models demonstrate rich dynamic behaviour, such as bouncing, floating, deflation and inflation.     

Hypermedia Models

This survey deals with questions of the organization and structuring of information. Hypermedia models of three basic categories are considered: (1) models of data structures, in which information is laid; (2) models of processes, which describe the semantics of the linking and browsing; and (3) combinational models that include structural and behavioral aspects of hypermedia.     

非线性NARMAX模型的ARMAX模型全局线性化

提出了基于NARMAX模型的非线性系统的全局线性化方法.该方法用时变的 ARMAX模型近似描述非线性NARMAX模型.证明了这一线性化方法的有界性,并给出了 相应的实现方法.仿真结果说明了该方法的有效性.     

利用现有模型修复不完整三维模型

针对通过扫描得到的三维模型经常不完整的问题,提出一种利用现有模型修复不完整扫描模型的方法.首先构建三维源模型库,将现有模型经过选取特征点等处理作为模型库中的源模型;然后选取待修复模型的特征点,通过比较源模型特征点和待修复模型特征点的一致程度,选择出合适的源模型;最后,通过匹配、变形、合并等步骤自动修复不完整模型,得到完整的三维扫描模型.实验结果表明,该方法能很好地修复不完整模型,得到的修复结果是既包含待修复模型的所有组成部分,又对其残缺部分进行合理修复的完整三维模型.     

SD Models: Super‐Deformed Character Models

Super‐deformed, SD, is a specific artistic style for Japanese manga and anime which exaggerates characters in the goal of appearing cute and funny. The SD style characters are widely used, and can be seen in many anime, CG movies, or games. However, to create an SD model often requires professional skills and considerable time and effort. In this paper, we present a novel technique to generate an SD style counterpart of a normal 3D character model. Our approach uses an optimization guided by a number of constraints that can capture the properties of the SD style. Users can also customize the results by specifying a small set of parameters related to the body proportions and the emphasis of the signature characteristics. With our technique, even a novel user can generate visually pleasing SD models in seconds.     

Integrating Software Models and Platform Models for Performance Analysis

System performance is a key factor to take into account throughout the software life cycle of modern computer systems, mostly due to their typical characteristics such as distributed deployment, code mobility, and platform heterogeneity. An open challenge in this direction is to integrate the performance validation as a transparent and efficient activity in the system development process. Several methodologies have been proposed to automate the transformation of software/hardware models into performance models. In this paper, we do not take a transformational approach; rather, we present a framework to integrate a software model with a platform model in order to build a performance model. Performance indices are obtained from simulation of the resulting performance model. Our framework provides a library of predefined resource models, model annotation and integration procedures, and simulation support that makes the performance analysis a much easier activity. We present the results obtained from two different industrial case studies that show the maturity and the stability of our approach     

Semantic Vector Models and Functional Models for Pregroup Grammars

We show that vector space semantics and functional semantics in two-sorted first order logic are equivalent for pregroup grammars. We present an algorithm that translates functional expressions to vector expressions and vice-versa. The semantics is compositional, variable free and invariant under change of order or multiplicity. It includes the semantic vector models of Information Retrieval Systems and has an interior logic admitting a comprehension schema. A sentence is true in the interior logic if and only if the ‘usual’ first order formula translating the sentence holds. The examples include negation, universal quantifiers and relative pronouns.