基于角色访问控制模型约束的OCL描述

基于角色的访问控制模型(RBAC)凭借其灵活的授权机制、强大的管理功能和完善的安全策略越来越引起人们的研究兴趣,随着研究的不断深入,面向对象的研究方法也逐渐应用到这个模型中,促进了它的迅速发展。UML作为一种强大的建模语言,不只是局限于支持面向对象的分析与设计,还支持从需求分析开始的软件开发的全过程,通过UML的描述可以使理论模型更加直观地应用到实际系统开发。该文使用UML的对象约束语言(OCL)来描述RBAC中的相关约束,使约束描述更加标准化,更有利于系统开发人员对模型的理解和促进RBAC模型的系统开发。     

From UML/OCL to SBVR specifications: A challenging transformation

UML is currently the most widely used modeling language for the specification of the conceptual schema (CS) of an information system (IS). However, UML falls short when it comes to allow business people to define in their own language (e.g. using their own terms in natural language) the policies and rules by which they run their business. To this purpose, the semantics of business vocabulary and business rules (SBVR) metamodel specification was proposed. SBVR is conceptualized optimally for business people and it is designed to be used for business purposes, independently of information systems designs.     

On OCL-based imperative languages

The Object Constraint Language (OCL) is a well-accepted ingredient in model-driven engineering and accompanying modeling languages such as UML (Unified Modeling Language) and EMF (Eclipse Modeling Framework) that support object-oriented software development. Among various possibilities, OCL offers the formulation of class invariants and operation contracts in form of pre- and postconditions, and side-effect free query operations. Much research has been done on OCL and various mature implementations are available for it. OCL is also used as the foundation for several modeling-specific programming and transformation languages. However, an intrusive way of embedding OCL into these language hampers us when we want to benefit from the existing achievements for OCL. In response to this shortcoming, we propose the language SOIL (Simple OCL-like Imperative Language), which we implemented in the UML and OCL modeling tool USE to amend its declarative model validation features. The expression sub-language of SOIL is identical to OCL. SOIL adds imperative constructs for programming in the domain of models. Thus by employing OCL and SOIL, it is possible to describe any operation in a declarative way and in an operational way on the modeling level without going into the details of a conventional programming language. In contrast to other similar approaches, the embedding of OCL into SOIL is done in a careful, non-intrusive way so that purity of OCL is preserved.     

UML/OCL工具的一致性检查研究

UML作为一种通用的可视化建模语言已被广泛应用,但UML模型的一致性问题一直限制着在软件开发中更有效地应用UML。本文阐述了UML模型一致性的相关概念,介绍了一种以OCL表示模型的一致性规则、并基于这些对模型进行一致性检查的方法。将此方法实现为一致性检查工具,提供了模型分析、语法检查和模型一致性检查等功能。     

Refinement and retrenchment for programming language data types

Refinement is a well-established and accepted technique for the systematic development of correct software systems. However, for the step from already refined specification to implementation, a correct refinement is often not possible because the data types used in the specification respectively the implementation language differ. In this paper, we discuss this problem and its consequences, using the integer data types of Java as an example, which do not correctly refine the mathematical integers ℤ. We present a solution, which can be seen as a generalisation of refinement and a variant of retrenchment. It has successfully been implemented as part of the KeY software verification system. Received November 2004 Revised July 2005 Accepted July 2005 by Eerke A. Boiten, John Derrick, Graeme Smith and Ian Hayes     

基于UML模型驱动的数据库设计与开发

面向对象的数据库开发框架对大型数据库应用的开发有重要作用 ,本文首先介绍了面向数据库开发框架的基本要求 ,然后介绍了UML对面向对象的数据库开发的支持 ,重点是介绍了OCL语言 ,最后用BorlandEco这样一个数据库开发框架开发了一个简易的模型 ,来显示UML模型驱动的数据库开发的巨大潜力。     

基于UML的本体表示方法研究

研究本体表示相关技术,并且从表达和推理能力等方面对当前本体表示方法进行分析和比较,总结各种表示方法的利弊。在此基础上提出一种基于统一建模语言（UML）和对象约束语言的本体表示方法,特别研究该表示方法的推理机制,并对这种表示方法进行应用。     

UML模型中并发对象的组合验证

本文在用层次自动机结构化表示UML Statecharts的基础上,定义了UML协同图中并发对象的同步合成,然后根据结构间的模拟关系,研究了对并发对象系统进行组合验证的方法和规则,使有可能在对UML协同图进行模型检验的过程中不必建立系统的全局状态图,以缓解状态爆炸问题。     

基于EMF和OCL的MDA软件工程方法研究

随着基于模型的软件工程方法的兴起,模型逐渐地变为软件工程中的重要元素,介绍了OMG规范MOF、XMI和OCL及在Eclipse软件工程环境下的相关实现EMF,说明了统一建模语言UML的使用方式和存在的问题,介绍了如何用EMF和OCL来设计建模语言,比较了基于EMF的建模语言和基于EBNF的计算机语言之间的区别与联系,给出了结合模板和OCL的模型转换方法,通过把UML类模型转换到O／R映射框架说明了此方法的有效性,分析了MDA软件工程方法的重用机制。     

OCL 1.4/5 vs. 2.0 Expressions Formal semantics and expressiveness

A type inference system and a big-step operational semantics for expressions of the Object Constraint Language (OCL), the declarative and navigational constraint language for the Unified Modeling Language (UML), are provided; the account is mainly based on OCL 1.4/5, but also includes the main features of OCL 2.0. The formal systems are parameterised in terms of UML static structures and UML object models, which are treated abstractly. It is proved that the operational semantics satisfies a subject reduction property with respect to the type inference system. Proceeding from the operational semantics and providing a denotational semantics, pure OCL 2.0 expressions are shown to exactly represent the primitive recursive functions, whereas pure OCL 1.4/5 expressions are Turing complete.     

搜索引擎系统：UML/OCL模型驱动开发

介绍一个搜索引擎系统的开发。运用UML用例图做系统的需求分析,运用UML类图、状态图、包图进行系统设计。以OCL表达式丰富状态图。使用C#语言和ASP.NET编程,SQL Server存储信息,系统运行在微软.NET环境上。遵循面向对象方法,如逐步求精和模块化,建立UML/OCL模型、组织程序,将系统逐层分解成具有特定功能的模块。系统由收集器、索引器、检索器三大部分组成,分别负责数据收集、数据分析和索引构建、用户检索接口。论文报告系统分析、设计和实现的思想和过程。     

Maintaining constraints of UML models in distributed collaborative environments

Constraint maintenance plays an important role in keeping the integrity and validity of UML models in embedded software design. While constraint maintenance capabilities are reasonably adequate in existing UML modeling applications, little work has been done to address the distributed constraint maintenance issue in multi-user collaborative modeling environments. The nature of the issue is to maintain constraint consistently across distributed sites in a collaborative modeling environment in the face of concurrency. In this paper, we propose a novel solution to this issue, which can retain the effects of all concurrent modeling operations even though they may cause constraint violations. We further contribute a distributed constraint maintenance framework in which the solution is encapsulated as a generic engine that can be mounted in a variety of single-user UML modeling applications to support collaborative UML modeling and distributed constraint maintenance in embedded software design processes. This framework has been implemented in a prototype distributed collaborative UML modeling application CoRSA.     

基于UML的适应调度知识系统开发

对复杂制造系统进行有效的适应调度,构建性能优良的知识系统是基础和核心。采用统一建模语言对适应调度知识系统的分析、设计和实现进行描述,建立了反映知识系统静态结构和动态行为的各种视图,使用对象约束语言对在系统设计中出现的类对象进行精确语义约束。使用这种建模技术减小了对领域知识专家的严重依赖,提高了知识系统开发的质量和效率。最后给出了应用实例验证该方法的可行性。     

基于本体的领域分析

软件复用被认为是改善软件质量和提高软件生产力最有希望的技术。为了支持复用,软件开发过程必须考虑两个方面的问题:为复用开发和用复用开发。本体逐渐成为构建信息系统、提供知识共享和复用的重要机制。领域分析是软件复用工程中最重要的工作。本课题利用本体的概念,讨论了领域分析技术中的领域本体的概念、领域本体的形式化描述,本体模型的UML表达,并给出基于本体的领域分析过程,以期对软件复用工程的领域分析过程有所改进。     

基于本体的领域分析

软件复用被认为是改善软件质量和提高软件生产力最有希望的技术。为了支持复用，软件开发过程必须考虑两个方面的问题：为复用开发和用复用开发。本体逐渐成为构建信息系统、提供知识共享和复用的重要机制。领域分析是软件复用工程中最重要的工作。本课题利用本体的概念．讨论了领域分析技术中的领域本体的概念、领域本体的形式化描述，本体模型的UML表达，并给出基于本体的领域分析过程．以期对软件复用工程的领域分析过程有所改进。     

Automatic software model checking via constraint logic

This paper proposes the use of constraint logic to perform model checking of imperative, infinite-state programs. We present a semantics-preserving translation from an imperative language with recursive procedures and heap-allocated mutable data structures into constraint logic. The constraint logic formulation provides a clean way to reason about the behavior and correctness of the original program. In addition, it enables the use of existing constraint logic implementations to perform bounded software model checking, using a combination of symbolic reasoning and explicit path exploration.     

PIM到关系PSM的转换方法研究

针对模型驱动体系结构中的模型转换问题,提出一种从PIM关系类图到SQL关系PSM的二步转换法,通过依赖、泛化、关联 3类关系的初步转换,使其脱离关系线,得到仅与属性类型相关的PIM类图,并对不同类型的属性制定相应的转换规则,利用一个具体示例展示了转换过程及其结果。实验结果表明,与简单的关联关系转换相比,该方法更全面,能够完整实现模型转换。     

An approach to test-driven development of conceptual schemas

Test-Driven Development (TDD) is an extreme programming development method in which a software system is developed in short iterations. In this paper we present the Test-Driven Conceptual Modeling (TDCM) method, which is an application of TDD for conceptual modeling, and we show how to develop a conceptual schema using it. In TDCM, a system's conceptual schema is incrementally obtained by performing three kinds of tasks: (1) Write a test the system should pass; (2) Change the schema to pass the test; and (3) Refactor the schema to improve its qualities. We also describe an integration approach of TDCM into a broad set of software development methodologies, including the Unified Process development methodology, the MDD-based approaches, the storytest-driven agile methods and the goal and scenario-oriented requirements engineering methods. We deal with schemas written in UML/OCL, but the TDCM method could be adapted to the development of schemas in other languages.