From UML Models to Graph Transformation Systems

In this paper we present an approach that allows to validate properties of UML models. The approach is based on an integrated semantics for central parts of the UML. We formally cover UML use case, class, object, statechart, collaboration, and sequence diagrams. Additionally full OCL is supported in the common UML fashion. Our semantics is based on the translation of a UML model into a graph transformation system consisting of graph transformation rules and a working graph that represents the system state. By applying the rules on the working graph, the evolution of the modeled system is simulated.     

Towards an Integrated Graph Based Semantics for UML

Recently, we proposed an integrated formal semantics based on graph transformation for central aspects of UML class, object and state diagrams. In this paper, we explain the basic ideas of that approach and show how two more UML diagram types, sequence and collaboration diagrams, can be captured. For UML models consisting of a class diagram and particular state diagrams, a graph transformation system can be defined. Its graphs are associated with system states and its rules with operations in the class diagram and transitions in the state diagrams. Sequence and collaboration diagrams then characterize sequences of operation applications and therefore sequences of transformation rule applications. Thus valid sequence and collaboration diagrams correspond to derivations induced by the graph transformation system. Proceeding this way, it can be checked for example whether such an operation application sequence may be applied in a specific system state.     

Dynamic Meta Modeling with time: Specifying the semantics of multimedia sequence diagrams

The Unified Modeling Langugage (UML) offers different diagram types to model the behavior of software systems. In some domains like embedded real-time systems or multimedia systems, it is necessary to include specifications of time in behavioral models since the correctness of these applications depends on the fulfillment of temporal requirements in addition to functional requirements. UML thus already incorporates language features to model time and temporal constraints. Such model elements must have an equivalent in the semantic domain.We have proposed Dynamic Meta Modeling (DMM), an approach based on graph transformation, as a means for specifying operational semantics of dynamic UML diagrams. In this article, we extend this approach to also account for time by extending the semantic domain to timed graph transformation. This enables us to define the operational semantics of UML diagrams with time specifications. As an example, we provide semantics for special sequence diagrams from the domain of multimedia application modeling.     

VPM: A visual,precise and multilevel metamodeling framework for describing mathematical domains and UML (The Mathematics of Metamodeling is Metamodeling Mathematics)

As UML 2.0 is evolving into a family of languages with individually specified semantics, there is an increasing need for automated and provenly correct model transformations that (i) assure the integration of local views (different diagrams) of the system into a consistent global view, and, (ii) provide a well-founded mapping from UML models to different semantic domains (Petri nets, Kripke automaton, process algebras, etc.) for formal analysis purposes as foreseen, for instance, in submissions for the OMG RFP for Schedulability, Performance and Time. However, such transformations into different semantic domains typically require the deep understanding of the underlying mathematics, which hinders the use of formal specification techniques in industrial applications. In the paper, we propose a multilevel metamodeling technique with precise static and dynamic semantics (based on a refinement calculus and graph transformation) where the structure and operational semantics of mathematical models can be defined in a UML notation without cumbersome mathematical formulae.     

可视化语言技术在软件开发中的应用

可视化语言技术比一维文本语言在描述软件组成方面具有优越性.由于图表和图形概念在系统建模中的广泛使用,可视化语言可以应用于需求分析、设计、测试和维护等软件开发的各个阶段.除了具有直观易见的特点之外,图文法在计算机上的精确建模和验证能力,为设计可视化语言提供了一个坚实的理论基础.讨论了可视化语言的形式理论基础,回顾了相关的可视化图形编程环境.特别提出了一种空间图文法,并且用该图文法定义了统一建模语言的行为语义.基于空间图文法,开发了一种基于模式驱动的框架,以帮助软件架构与设计.     

UML的形式化描述语义

本文提出了一种新的定义UML形式化语义的方法。我们将建模语言的语义区分为描述语义和功能语义两个方面。描述语义定义哪些系统满足模型,功能语义定义模型中的基本概念。本文用一阶逻辑定义了UML的类图、交互图和状态图的描述语义,并介绍我们实现的将UML模型转换成逻辑系统的软件工具LAMBDES,该工具集成了定理证明器SPASS,可以对模型进行自动推理。我们成功地将此方法和工具应用于模型的一致性检查。     

Automated formal verification of visual modeling languages by model checking

Graph transformation has recently become more and more popular as a general, rule-based visual specification paradigm to formally capture (a) requirements or behavior of user models (on the model-level), and (b) the operational semantics of modeling languages (on the meta-level) as demonstrated by benchmark applications around the Unified Modeling Language (UML). The current paper focuses on the model checking-based automated formal verification of graph transformation systems used either on the model-level or meta-level. We present a general translation that inputs (i) a metamodel of an arbitrary visual modeling language, (ii) a set of graph transformation rules that defines a formal operational semantics for the language, and (iii) an arbitrary well-formed model instance of the language and generates a transitions system (TS) that serve as the underlying mathematical specification formalism of various model checker tools. The main theoretical benefit of our approach is an optimization technique that projects only the dynamic parts of the graph transformation system into the target transition system, which results in a drastical reduction in the state space. The main practical benefit is the use of existing back-end model checker tools, which directly provides formal verification facilities (without additional efforts required to implement an analysis tool) for many practical applications captured in a very high-level visual notation. The practical feasibility of the approach is demonstrated by modeling and analyzing the well-known verification benchmark of dining philosophers both on the model and meta-level.     

UML状态机的形式语义

许多大型系统在进行分析和设计时,均采用UML作为需求描述语言,尤其是一些对安全性要求较高的系统,更是广泛采用UML的动态行为描述机制--状态机来描述协议及控制机制.但是,由于UML没有形式化的动态语义,不利于对其所描述的需求进行形式化验证和证明.为了解决这一问题,采用以下方法为UML状态机构建形式语义.把UML状态机中的状态映射到一种项代数上,用归纳的状态项表示状态机的状态.然后,把状态项映射到一种加标记的变迁系统LTS上,LTS-状态是状态机的状态项,LTS-变迁是UML状态机的微步.最后,用Plotk     

A compositional semantics of UML-RSDS

This paper provides a semantics for the UML-RSDS (Reactive System Development Support) subset of UML, using the real-time action logic (RAL) formalism. We show how this semantics can be used to resolve some ambiguities and omissions in UML semantics, and to support reasoning about specifications using the B formal method and tools. We use ‘semantic profiles’ to provide precise semantics for different semantic variation points of UML. We also show how RAL can be used to give a semantics to notations for real-time specification in UML. Unlike other approaches to UML semantics, which concentrate on the class diagram notation, our semantic representation has behaviour as a central element, and can be used to define semantics for use cases, state machines and interactions, in addition to class diagrams.     

UML2．0类图的一种形式化描述方法

UML类图是根据系统中的类，以及各个类之间的关系来描述系统的静态视图。基于UML缺乏精确语义描述的不足，我们提出了基于时序逻辑语言XYZ／E来表示类图形式化语义的方法。通过对UML2．0类图元素及其特点的分析，找出类图元素的形式化描述规则，利用转换法实现了对UML2．0类图的XYZ／E形式化描述。     

UML状态机的模型检验方法

模型检验是一种确保设计规范正确性的形式化自动验证技术,本文提出了对UML状态机进行模型检验的方法。文中首先对UML状态机的语法和语义进行描述,然后基于语义中的RTC步给出生状态机全局可达状态迁移图的方法,方法的核心是在当前格局下根据使能条件确定所有的最大无冲突迁移集。文章最后给出算法以验证UML状态机是否满足用计算树逻辑（CTL）公式表示的性质。     

Dynamic Meta Modeling with Time: Specifying the Semantics of Multimedia Sequence Diagrams

UML offers different diagram types to model behavior and dynamics of software systems. In some domains like embedded real-time systems or multimedia systems, it is necessary to include specifications of time since the correctness of these applications depends on the fulfillment of temporal requirements in addition to functional requirements. UML thus already incorporates language features to model time and temporal constraints. Such model elements must have an equivalent in the semantic domain. We have proposed Dynamic Meta Modeling (DMM) as a means for the specification of the formal operational semantics of UML models by applying graph transformation to the meta modeling of dynamic behavior. Within this paper, we extend this approach to also account for time by building on timed graph transformations. We apply these concepts to the domain of multimedia application modeling in which we adopt UML sequence diagrams. The DMM rules with time then specify an interpreter that can be used to analyze or test a model of multimedia sequence diagrams.     

UML2.0顺序图的形式化研究

在UML2.0规范中顺序图的语义仍然是以自然语言的形式描述的,为实现对顺序图的自动化分析和验证,必须为顺序图定义一种形式化的语义模型.为此首先给出了UML顺序图的一种符合BNF范式的形式化语法,然后为该语法中的非终止符定义转换规则,将UML顺序图中的基本动作转换为加标Petri网组件,最后定义了各种合成操作,利用这些合成操作可以将UML顺序图的加标Petri网组件转换为加标Petni网.     

Automated transformations from UML behavior models to contracts

In model driven architecture （MDA）, system requirements are first captured by UML （unified mod- eling language） use cases with sequence diagrams to describe their intended use and implemented by classes of objected-oriented languages in the subsequent design stages. It is important that the dynamic behavior specified by the sequence diagrams is in full compliance with the implementation classes. This paper proposes an auto- matic approach and tool support for generating class contracts, which define a precondition and a postcondition for each operation of the class. The former serves as a guard to ensure invocations of the operations respect the semantics introduced by the sequence diagrams, and the latter places the system in a legal state to facilitate the succeeding operation calls. The contracts can be easily mapped to code of an object-oriented language such as Java. Thus, the approach helps to bridge the gap between the requirements and design stages of system development process. We use our model transformation tool to first generate a UML protocol state machine from the sequence diagrams, and then derive the contracts for a controller class. The transformations take into account the concurrency and critical constructs of the respective UML diagrams.     

Towards a Formal Semantics for UML/MARTE State Machines Based on Hierarchical Timed Automata

UML is a widely-used,general purpose modeling language.But its lack of a rigorous semantics forbids the thorough analysis of designed solution,and thus precludes the discovery of significant problems at design time.To bridge the gap,the paper investigates the underlying semantics of UML state machine diagrams,along with the time-related modeling elements of MARTE,the profile for modeling and analysis of real-time embedded systems,and proposes a formal operational semantics based on extended hierarchical timed automata.The approach is exemplified on a simple example taken from the automotive domain.Verification is accomplished by translating designed models into the input language of the UPPAAL model checker.     

Concurrency and Refinement in the Unified Modeling Language

This paper defines a formal semantics for a subset of the Unified Modeling Language (UML). It shows how suitable combinations of class, object, state, and sequence diagrams can be associated with patterns of interaction, expressed in the event notation of Communicating Sequential Processes (CSP). The diagram semantics is then extended to give a meaning to complete models – suitable combinations of diagrams – and thus a concurrency semantics for object models written in UML. This model semantics is in turn used to define a theory of refinement, based upon existing notions of data and process refinement.     

UML活动图的时序逻辑语义

UML活动图可以表示不同抽象级的控制流,很适合用于对系统的行为建模．但是缺乏精确的语义使得难以对它所表示的系统行为进行分析．XYZ／E是一可执行线性时序逻辑语言,既可描述系统的动态行为又可表示程序性质,用它对活动图形式化后,就可在统一的逻辑框架下分析活动图的性质．定义了一个有向图结构用以表示UML活动图,再给出其XYZ／E语义,并用一个例子说明活动图到XYZ／E的语义转换,为进一步的分析提供形式化基础．