形式化语言B与UML/OCL的比较

该文介绍了形式化方法中B语言和UML/OCL语言,从软件开发生命周期的角度对B语言和OCL语言进行了比较,归纳了这两种形式化语言的异同和各自的适用范围。     

OCL数据类型到B形式化规约的转换

研究了UML模型到B形式化规约的转换。提出了一套从OCL数据类型及定义在这些数据类型上的操作到BAMN的转换规则。OCL的Boolean类型和Integer类型分别对应于B中的BOOL类型和Z类型;OCL中的String类型需用B抽象机器重新定义新的数据类型Char_TYPE和String_TYPE来进行规约;OCL中的REAL类型采用B中的记录表达式进行近似模拟;OCL中的Collection类型（包括Set,Orderedset,Bag,Sequence）用B语言中的set,sequence,tree等进行近似模拟。     

OCL与Object-Z作为UML约束语言的分析比较

UML是目前广泛使用的标准的面向对象建模语言。为了提高建模的精确性,UML模型可以用对象约束语言OCL或者是用Object-Z规格说明语言加以补充说明。本文从多个方面分析比较了这两种语言的特点,并提出建模人员应充分利用这两种语言的特点,对系统进行精确的建模。     

基于B的UML形式化需求分析

为了消除软件需求中存在的不完整性、二义性和不一致性,可以用形式化方法描述软件需求;但是,形式化描述需要很强的专业知识,这样严重阻碍其广泛应用。为了使形式化描述简单、易行,提出了一种从UML试图转化为B形式化需求的一种新的实现方法,该方法通过在实际的项目中应用,取得了一定的效果。     

基于B的UML形式化需求分析

为了消除软件需求中存在的不完整性、二义性和不一致性,可以用形式化方法描述软件需求;但是,形式化描述需要很强的专业知识,这样严重阻碍其广泛应用。为了使形式化描述简单、易行,提出了一种从UML试图转化为B形式化需求的一种新的实现方法,该方法通过在实际的项目中应用,取得了一定的效果。     

基于B语言的UML形式化方法

分析了目前主要的UML形式化方法及特点,提出了基于B语言的转换方法B2F(B-Based Formalization),通过将UML模型转化为B抽象机描述实现UML的形式化描述和验证,并详细分析了基于B2F方法的UML类图的形式化,证明了该方法的可行性。     

基于Petri网和B语言集成的形式化方法

本文中提出了一种能够描述分布式系统和实时系统的形式化方法-Petri-B 网，Petri-B 网是集成了 Petri 网理论 和 B 语言的形式化方法，它不仅具有了 Petri 网的特点，还具备了 B 语言的长处。本文定义了 Petri-B 网并用它来描述一个座位预 订系统。     

B语言和方法与Z、VDM的比较

1 引言形式化方法是建立在严格数学基础上的软件开发方法。软件开发的全过程中,从需求分析、规格说明、设计、编程、系统集成、测试、文档生成直至维护各阶段,凡是采用严格的数学语言、具有精确的数学语义的方法都称为形式化方法。形式化方法的一个重要研究内容是形式规格说明,即用具有精确语义的形式化语言书写的程序功能描述,它是论证程序是否正确的依据。形式化方法需要形式规格说明语言的支持,也可以说形式化方法的关键在于形式规格说明语言。形式规格说明语言提供了一个称为语法域的记号系统和一个称为语义域的目标集合,以及一组精确地定义哪些目标系统满足哪个规格说明的规则。根据对目标软件系统进行说明的方式分三种规格说明语言:     

集成CCS和B语言的形式化方法

本文尝试集成通信系统演算（CCS）和B语言,以扩展CCS在数据和操作定义方面的能力,以及B方法在描述并发系统方面的能力。集成后的形式化模型BCCS可以描述和分析系统的不同方面（结构、控制、数据和功能）和不同类型的系统（顺序、并发和分布式）。     

形式化方法Designware、B的比较

用形式化方法开发软件是提高软件可靠性和开发效率的革命性途径。Designware、B是两种支持软件开发全过程的形式化方法。对它们的规约描述方法、规约求精方式、开发步骤进行比较,最后分析这两种方法各自的优缺点。     

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。     

带OCL约束条件的类图到Object-Z规格说明的转换

如何提高软件的可靠性是目前软件研究领域的一个热点。将形式化方法和主流的软件开发方法相结合是一个可行的方法。本文研究UML语言和Object-Z语言相结合的方法,为主流的软件开发人员所使用的图形化规格说明技术与形式方法提供的精确的分析和验证技术架起了一座桥梁。本文定义如何将带0CL约束条件的类图转换到Object-Z规格说明的方法。这样不仅可以通过支持Object-Z语言的工具采对UML语言描述的系统性质进行验证和确认,而且能够帮助规格说明人员方便地构造Object-Z规格说明。     

形式语言B与RSL的比较

本文介绍了形式化方法中B方法和RAISE方法,从软件开发生命周期的角度对B语言和RSL进行了比较,归纳了这两种形式化语言的异同和各自的适用范围。     

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.     

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.     

Incremental integrity checking of UML/OCL conceptual schemas

Integrity constraints play a key role in the specification and development of software systems since they state conditions that must always be satisfied by the system at runtime. Therefore, software systems must include some kind of integrity checking component that ensures that all constraints still hold after the execution of any operation that modifies the system state. Integrity checking must be as efficient as possible not to seriously slow down the system performance at runtime. In this sense, this paper proposes a set of techniques to facilitate the efficient integrity checking of UML-based software specifications, usually complemented with a set of integrity constraints defined in Object Constraint Language (OCL) to express all rules that cannot be graphically defined. In particular, our techniques are able to determine, at design-time, when and how each constraint must be checked at runtime to avoid irrelevant verifications. We refer to these techniques as incremental because they minimize the subset of the system state that needs to be checked after each change by assuming that the system was initially in a consistent state and just reevaluating the elements that may have been affected by that change. We also show how the techniques can be integrated in a model-driven development framework to automatically generate a final implementation that automatically checks all constraints in an incremental way.     

A feedback technique for unsatisfiable UML/OCL class diagrams

In Model‐Driven Development (MDD), detection of model defects is necessary for correct model transformations. Formal verification tools and techniques can to some extent verify models. However, scalability is a serious issue in relation to verification of complex UML/OCL class diagrams. We have proposed a model slicing technique that slices the original model into submodels to address the scalability issue. A submodel can be detected as unsatisfiable if there are no valid values for one or more attributes of an object in the diagram or if the submodel provides inconsistent conditions on the number of objects of a given type. In this paper, we propose a novel feedback technique through model slicing that detects unsatisfiable submodels and their integrity constraints among the complex hierarchy of an entire UML/OCL class diagram. The software developers can therefore focus their revision efforts on the incorrect submodels while ignoring the rest of the model. Copyright © 2013 John Wiley & Sons, Ltd.     

Refactoring OCL annotated UML class diagrams

Refactoring of UML class diagrams is an emerging research topic and heavily inspired by refactoring of program code written in object-oriented implementation languages. Current class diagram refactoring techniques concentrate on the diagrammatic part but neglect OCL constraints that might become syntactically incorrect by changing the underlying class diagram. This paper formalizes the most important refactoring rules for class diagrams and classifies them with respect to their impact on attached OCL constraints. For refactoring rules that have an impact on OCL constraints, we formalize the necessary changes of the attached constraints. Our refactoring rules are specified in a graph-grammar inspired formalism. They have been implemented as QVT transformation rules. We finally discuss for our refactoring rules the problem of syntax preservation and show, by using the KeY-system, how this can be resolved.