Hybrid MARTE statecharts

The specification of modeling and analysis of real-time and embedded systems (MARTE) is an extension of the unified modeling language (UML) in the domain of real-time and embedded systems. Even though MARTE time model offers a support to describe both discrete and dense clocks, the biggest effort has been put so far on the specification and analysis of discrete MARTE models. To address hybrid real-time and embedded systems, we propose to extend statecharts using both MARTE and the theory of hybrid automata. We call this extension hybrid MARTE statecharts. It provides an improvement over the hybrid automata in that: the logical time variables and the chronometric time variables are unified. The formal syntax and semantics of hybrid MARTE statecharts are given based on labeled transition systems and live transition systems. As a case study, we model the behavior of a train control system with hybrid MARTE statecharts to demonstrate the benefit.     

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.     

基于MDA的MARTE模型形式化方法

针对嵌入式系统对可靠性和可预测性的要求,提出基于MDA对嵌入式系统的建模语言MARTE进行形式化描述的方法。建立Object-Z的元模型,定义了MARTE元模型与Object-Z元模型之间的模型转换关系,给出了MARTE模型到Object-Z模型的语义映射和语法转换的具体过程。该方法支持将MARTE模型形式化转换为Object-Z模型,有利于软件开发早期的检验和验证。     

UML活动图的操作语义

越来越多的系统采用UML（unified model language,统一建模语言）作为建模语言来进行系统分析和设计.UML活动图是UML语言中描述系统动态行为的一种方法,它广泛地运用于业务建模.由于UML活动图缺乏精确的动态语义,所以不利于对其所描述的系统进行形式化的分析、验证和确认.为解决这一问题,根据UML1.5语义文档,给出UML活动图的形式化操作语义.首先给出UML活动图的形式化的语法,然后详细地定义了活动图的格局和变迁,最后基于LTS给出了活动图的演绎规则.主要工作是：引入状态包的概念,使得描述更加清楚、完善;通过LTS定义活动图的操作语义,并详细阐述演绎规则,从而获得活动图的全局状态转移图,使定义的操作语义很容易地应用到形式化验证中.该语义覆盖了UML活动图的绝大部分特征,为对UML活动图进行模型检验奠定了基础.     

UML类图的形式化及分析

统一建模语言(UML)是一种通用的图形化建模语言,在面向对象系统的分析和设计中,它已成为事实上的工业标准。但是UML不是形式化的建模语言,缺乏精确的语义描述,因此会导致一些问题。Z是一种广泛使用的形式化规约语言,Z适合用来精确地表示模型的语法和语义。文章采用Z符号来表示UML类图的组成元素的语法和语义及其映射关系,最后对UML类图的一些性质进行分析和验证。     

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.     

Timing consistency checking for UML/MARTE behavioral models

UML/MARTE model-driven development approaches are gaining attention in developing real-time embedded software (RTES). UML behavioral models with MARTE annotations are used to describe timing behaviors and timing characteristics of RTES. Particularly, state machine, sequence, and timing diagrams with MARTE annotations are appropriate to understand and analyze timing behaviors of RTES. However, to guarantee software correctness and safety, timing inconsistencies in UML/MARTE should be identified in the design phase of RTES. UML/MARTE timing inconsistencies are related to modeling errors and can be hazards throughout the lifecycle of RTES. We propose a systematic approach to check timing consistency of state machine, sequence, and timing diagrams with MARTE annotations for RTES. First, we present how state machine, sequence, and timing diagrams with MARTE annotations specify the behaviors of RTES. To overcome informal semantics of UML/MARTE models, we provide formal definitions of state machine, sequence, and timing diagrams with MARTE annotations. Second, we present the timing consistency checking approach that consists of a rule-based and a model checking-based timing consistency checking. In the rule-based timing consistency checking, we validate well formedness of UML/MARTE behavioral models in timing aspects. In the model checking-based timing consistency checking, we verify whether timing behaviors of sequence and timing diagrams with MARTE annotations are consistent with the timing behaviors of state machine diagrams with MARTE annotations. We support an automated timing consistency checking tool UML/MARTE timing Consistency Analyzer for a seamless approach. We demonstrate the effectiveness and the practicality of the proposed approach by two case studies using cruise control system software and guidance and control unit software.     

基于MDE的异构模型转换:从MARTE模型到FIACRE模型

通过研究一个具有代表性的UML/MARTE(unified modeling language/modeling and analysis of real timeand embedded systems)模型向FIACRE(intermediate format for the architectures of embedded distributed components)形式模型的转换实例,探讨了异构模型之间在语义和语法层的相互转换问题.在语义层,通过模型转换技术构造语义映射规则,实现元语言之间的转换;在语法层,通过构造元模型的具体语法,反映元语言的语法规则,从而产生目标模型的程序实体.基于此实例研究,探讨了通用转换途径的相关框架和关键技术,并讨论了转换工作的优缺点和实 用性.     

UML活动图描述工作流模型的执行语义

UML是软件工程中广泛应用的建模语言,但其主要问题是缺少严格的形式化语义,因而描述的模型容易产生歧义．根据UML活动图的语法和工作流系统的特点,为UML活动图定义了一种执行语义．基于时间转变系统模型,将工作流系统的执行描述为时间转变和数据转变两个交替进行的过程．时间转变描述时间的前进,数据转变修改工作流案例的状态,这种语义比层次状态图具有更强的描述并行的能力,比Petri网和进程代数更适合描述工作流模型．     

模型驱动的嵌入式系统设计安全性验证方法研究

基于模型的嵌入式系统安全性分析与验证方法是近年来在安全攸关系统工程领域中出现的一个重要研究热点。提出一种基于模型驱动架构的面向SysML/MARTE状态机的系统安全性验证方法,具体包括:构建了具备SysML/MARTE扩展语义的状态机元模型,以及安全性建模与分析语言AltaRica的语义模型GTS的元模型;然后建立了从SysML/MARTE状态机模型分别到时间自动机模型以及AltaRica模型的语义映射模型转换规则,并基于AMMA平台和时间自动机验证工具UPPAAL设计实现了对SysML/MARTE状态机的模型转换与系统安全性形式化验证的框架。最后给出了一个飞机着陆控制系统设计模型的安全性验证实例分析。     

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.     

A dependability profile within MARTE

The importance of assessing software non-functional properties (NFP) beside the functional ones is well accepted in the software engineering community. In particular, dependability is a NFP that should be assessed early in the software life-cycle by evaluating the system behaviour under different fault assumptions. Dependability-specific modeling and analysis techniques include for example Failure Mode and Effect Analysis for qualitative evaluation, stochastic Petri nets for quantitative evaluation, and fault trees for both forms of evaluation. Unified Modeling Language (UML) may be specialized for different domains by using the profile mechanism. For example, the MARTE profile extends UML with concepts for modeling and quantitative analysis of real-time and embedded systems (more specifically, for schedulability and performance analysis). This paper proposes to add to MARTE a profile for dependability analysis and modeling (DAM). A case study of an intrusion-tolerant message service will offer insight on how the MARTE-DAM profile can be used to derive a stochastic Petri net model for performance and dependability assessment.     

将UML模型转换成SDL模型的方法

提出了一种将UML模型转换成SDL模型的方法.UML是一种优秀的建模语言,使用UML可以为协议建立模型带来很多方便.但是,UML缺乏形式化语义,因此不能满足协议精确性的要求.SDL是一种用于通信软件规格的标准语言,它拥有形式化语义,而且有很多商业软件都支持它.在协议设计和开发中,将UML模型转换成SDL模型可以克服这样的缺点.通过为UML制作适当的profile,并制定严格的转换规则可以实现模型的转换.     

MARTE顺序图到TTS4SD的转换

MARTE对UML的顺序图进行了扩充,使其适用于实时系统的建模阶段,但它不能直接用于正确性验证阶段。对象管理组织提出用模型转换的方法将依照MARTE构造的顺序图(记为A)转换成具有完备的验证方法和工具的形式化模型(记为B)。用B表示A的语义可以保证B能够完整且准确地模拟A的行为。提出了形式化模型——TTS4SD,用来描述MARTE顺序图的形式语义,并在此基础上展开了验证。首先给出顺序图的形式定义,把时间变迁系统(TTS)扩充成TTS4SD;然后用TTS4SD描述顺序图的形式语义,并给出从顺序图到TTS4SD的转换算法;最后对TTS4SD展开分析。通过一个实例说明了从顺序图到TTS4SD的转化过程以及基于TTS4SD的验证方法。     

The UML as a formal modeling notation

The Unified Modeling Language (UML) is an Object Management Group (OMG) object-oriented (OO) modeling notation standard. It consists of a set of notations for modeling systems from a variety of views and at varying levels of abstraction. While the UML reflects some of the best OO modeling experiences available, it suffers from a lack of precise semantics that is necessary if one is to use the notations to precisely model systems and to rigorously reason about the models. In this paper we discuss some of the problems with the current UML semantic document and present the approach that the precise UML group (pUML) group is using to develop a precise semantics for the UML. The approach utilizes mathematical techniques to explore and gain insights into appropriate semantics for UML modeling concepts. The insights and formal expressions will then be used to develop a UML semantics document written in natural language that defines the semantics in a precise, consistent, and understandable manner.     

Safe design of high-performance embedded systems in an MDE framework

In this paper, we use the UML MARTE profile to model high-performance embedded systems (HPES) in the GASPARD2 framework. We address the design correctness issue on the UML model by using the formal validation tools associated with synchronous languages, i.e., the SIGALI model checker, etc. This modeling and validation approach benefits from the advantages of UML as a standard, and from the number of validation tools built around synchronous languages. In our context, model transformations act as a bridge between UML and the chosen validation technologies. They are implemented according to a model-driven engineering approach. The modeling and validation are illustrated using the multimedia functionality of a new-generation cellular phone.     

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     

基于MDA的实时软件资源建模与模型转换的方法

模型驱动体系结构(MDA)是一种以模型为中心的软件开发框架,其本质是元建模与模型转换。提出了一种基于MDA的实时软件资源建模与模型转换的方法。首先通过元建模抽象出包含资源信息的MARTS元模型以及价格时间自动机的元模型;然后利用模型转换语言ATL对MARTS元模型和价格时间自动机元模型构造转换规则,通过将对应的实例模型进行相互转换,实现在MDA下MAR"I'E模型到价格时间自动机模型的转换;最后通过形式化工具UPPAAL对模型转换结果进行形式化验证。实例分析表明了该方法的可行性与有效性,它能够提高实时软件资源建模的可信性。     

基于Object—Z的UML对象模型的形式化

1 引言 UML作为面向对象的可视化建模语言,己被对象管理集团(OMG)作为面向对象分析和设计的标准,获得了众多工具的支持。UML提供了不同抽象层次的描述以支持面向对象的分析、设计和实施,它从不同的视图描述软件系统,减少了建模的复杂度,更为重要的是建立了基于元模型的体系结构,提供了较为灵活的扩充机制,使开发人员可以根据不同的领域需求定制UML,也易于加入新的建模概念。