基于UML实时系统的分析和设计

介绍了统一建模语言的最新版本UML2及应用UML2进行实时系统设计的作用及意义.探讨了UML2中用在实时系统设计中的概念.结合一个使用UML2为家庭安全系统设计的例子,着重分析了系统的静态结构和动态行为,通过类图、顺序图、状态图等UML图描述系统的方法从整体上对系统建模,说明实时系统分析与设计过程.使用UML分析和设计系统能够提高软件设计的效率和质量增强软件的维护性和复用性.     

基于UML实时系统设计方法的分析与比较

总结了目前UML在实时系统设计中应用的现状,介绍了UML实时扩展的各种技术和方法,通过对实时系统可调度性、可预测性、安全性等实时性能的描述,比较了各种常用的技术和方法的优缺点,并对现有方法的局限性提出了UML实时扩展中尚待解决的问题及新的研究方向,对UML实时系统的应用设计提出了参考建议。     

基于UML和μC/OS-Ⅱ的嵌入式系统设计

将UML用于μC／OS-Ⅱ的结构描述，进而用于以μC／OS-Ⅱ为实时操作平台的嵌入式系统设计。文中首先建立了μC／OS-Ⅱ的UMI。静态模型，并给出其类图描述的详细分析；然后，以嵌入式文件系统设计为实例，详细分析了利用UML开发基于μC／OS-Ⅱ嵌入式系统的整个过程。实验结果表明：采用UML对于以RTOS为操作平台的32位嵌入式系统复杂设计，是一种构造清晰，易于修改的有效途径。     

基于UML的学生管理信息系统的研究与设计

文章以学生管理信息系统为例,运用UML中视图对系统设计各阶段进行描述,介绍了UML在系统设计中的应用。     

UML嵌入式系统设计

UML是当今最流行的标准建模语言,嵌入式系统是以应用为中心、以计算机技术为基础的专用计算机系统,是软件和硬件的综合体;而嵌入式系统设计的好坏是数字商品成功荫关键。本文重点讨论UML建模中重要的概念,以及如何在嵌入式系统设计中使用UML OOD建模技术,并结合实例“微波炉小灯”演示采用UML的嵌入式系统设计过程。     

使用UML对μC/OS-II建模与分析

使用统一建模语言（UML）对嵌入式实时操作系统C/OS-II做静态建模和动态建模,进而利用UML的可视化模型来描述和分析C/OS-II的系统结构和工作机理。通过UML静态建模,为基于C/OS-II的嵌入式系统设计,提供了一个运用面向对象技术的框架;通过UML动态建模,详细分析了嵌入式实时操作系统（ERTOS）的关键方面,包括实时内核的调度机理、优先级反转问题及其解决办法等。     

UML嵌入式系统设计

UML是当今最流行的标准建模语言,嵌入式系统是以应用为中心、以计算机技术为基础的专用计算机系统,是软件和硬件的综合体;而嵌入式系统设计的好坏是数字商品成功的关键。本文重点讨论UML建模中重要的概念,以及如何在嵌入式系统设计中使用UMLOOD建模技术,并结合实例微波炉小灯演示采用UML的嵌入式系统设计过程。     

UML在嵌入式系统设计中的应用

介绍了UML及将UML应用于嵌入式系统设计中的作用和意义;分析了在嵌入式系统设计中应用UML的基本步骤和难点;结合车载GPS终端系统的设计,描述了一个UML的具体应用过程。     

使用UML对μC/OS-Ⅱ建模与分析

使用统一建模语言(UML)对嵌入式实时操作系统μC/OS-Ⅱ做静态建模和动态建模,进而利用UML的可视化模型来描述和分析μC/OS-Ⅱ的系统结构和工作机理.通过UML静态建模,为基于μC/OS-Ⅱ的嵌入式系统设计,提供了一个运用面向对象技术的框架;通过UML动态建模,详细分析了嵌入式实时操作系统(ERTOS)的关键方面,包括实时内核的调度机理、优先级反转问题及其解决办法等.     

基于UML的嵌入式建模方法改进策略研究

统一建模语言UML(unified modeling language)在嵌入式系统设计建模中已经获得了广泛的承认,有很多成功的应用.但UML在嵌入式建模中存在时间约束描述能力不强和所建模型形式化复杂、验证难及模型重用性不高等问题.针对这些问题提出了一种改进策略:定义实时语义和映射规则,建立实时描述模式模板,使用模板中实时描述模式描述时间约束信息.改进后的方法能可视化地分析模型、纠正错误和简单地进行形式化转换,能利用支撑工具对模型进行验证,较好地解决了UML在嵌入式系统建模中存在的问题.     

Towards UML-based formal specifications of component-based real-time software

UML-RT is achieving increasing popularity as a modeling language for real-time applications. Unfortunately UML-RT is not formally well defined and it is not well suited for supporting the specification stage: e.g., it does not provide native constructs to represent time and non-determinism. UML+ is an extension of UML that is formally well defined and suitable for expressing the specifications of real-time systems (e.g., the properties of a UML+ model can be formally verified). However, UML+ does not support design and development. This article addresses the translation of UML+ into UML-RT, thus posing the basis for a development framework where UML+ and UML-RT are used together, in order to remove each other’s limitations. Specifications are written using UML+, they are automatically verified by means of formal methods, and are then converted – through a semi-automatic process – in an equivalent UML-RT model that becomes the starting point for the implementation.     

实时UML及其在月球车实时软件开发中的应用

实时UML(UML-RT)是统一建模语言(Unified Modeling Language,UML)在实时系统的扩展和应用,其简洁清晰的面向对象可视化建模方法可以有效解决实时系统中的复杂建模问题;分析了应用实时UML概念和原理进行实时系统可视化建模的问题和方法,并以包含多个子系统的复杂实时系统-月球车系统为例,论述了应用实时UML进行实际软件设计的过程和问题;使用实时UML使得设计过程形象和易于组织,同时方便了项目成员间的交流,大大加快了软件开发的进程。     

QoS-oriented design of embedded systems with specification PEARL

Only recently have methodical tools adequate to design real-time systems been formally introduced in design methodologies. Naturally, they were present from the beginning, but due to the large diversity of embedded systems’ areas of deployment, specially dedicated formalisms have been developed and used. High-level language programming and integration of modeling formalisms into design methods eased the development of more complex real-time applications. With the emerging object-oriented programming languages and design methods, their integration into larger information systems has become more transparent. It was the UML methodology, however, which eventually merged also the design methods and concepts of real-time systems into a consistent whole. It took a large consortium and a long process to persuade industry of the benefits the new integral methodology can offer. On the other hand, there are some trade-offs, and there are some features not completely covered, yet. Here, a different, more straightforward approach to program and design (embedded) real-time systems is presented. Since it emerged from the real-time community, it includes most features relevant there. Independent of the UML profile for schedulability, performance and time specification, a profile was devised for use in PEARL-oriented UML design. The strengths of the mentioned language and design methods for QoS-oriented design of (embedded) real-time systems are emphasised throughout this article.     

Clock constraint specification language: specifying clock constraints with UML/MARTE

The Object Management Group (OMG) unified modeling language (UML) profile for modeling and analysis of real-time and embedded systems (MARTE) aims at using the general-purpose modeling language UML in the domain of real-time and embedded (RTE) systems. To achieve this goal, it is absolutely required to introduce inside the mainly untimed UML an unambiguous time structure which MARTE model elements can rely on to build precise models amenable to formal analysis. The MARTE Time model has defined such a structure. We have also defined a non-normative concrete syntax called the clock constraint specification language (CCSL) to demonstrate what can be done based on this structure. This paper gives a brief overview of this syntax and its formal semantics, and shows how existing UML model elements can be used to apply this syntax in a graphical way and benefit from the semantics.     

Modeling distributed real-time applications with specification PEARL

The methodology of hardware/software co-design of embedded control systems with Specification PEARL is presented. Hardware and software are modeled with the language Specification~PEARL, which has its origins in standard Multiprocessor~PEARL. Its usefulness is enhanced for modeling hierarchical and asymmetrical multiprocessor systems, and by additional parameters for schedulability analysis. Graphical symbols are introduced for its constructs to enable graphical modeling while maintaining the semantical background. It is meant to be a superlayer for programs, based on the PEARL programming model. To model program tasks, Timed State Transition Diagrams have been defined. The model of a co-designed system is verified for feasibility with co-simulation. The resulting information should be used when considering changes in a current design with the goal of producing a temporally feasible model. To support dynamic re-configurations, configuration management is introduced into the models. Since UML is becoming a de facto standard also for designing embedded control systems, and since Timed State Transition Diagrams and State Chart Diagrams share great similarity, an interface of the methodology to UML 2 is defined, using UML's extension mechanisms.     

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.     

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.     

A generic framework for modeling heterogeneous real-time systems

Complex real-time systems usually consist of heterogeneous components. These components interact with different semantics. Modeling these systems normally need integrating several domain-specific tools such as UML, Simulink. But interchanging data between these tools is very difficult. UML is a standard modeling language for object-oriented software development, used more and more in real-time domain. It provides several extensibility mechanisms to allow modeling special domains. This paper presents a generic framework, which is based on UML notations and metamodels, for heterogeneous modeling real-time systems. So engineers from different domains can work together on a unified platform.     

Performance modeling and analysis of message-oriented event-driven systems

Message-oriented event-driven systems are becoming increasingly ubiquitous in many industry domains including telecommunications, transportation and supply chain management. Applications in these areas typically have stringent requirements for performance and scalability. To guarantee adequate quality-of-service, systems must be subjected to a rigorous performance and scalability analysis before they are put into production. In this paper, we present a comprehensive modeling methodology for message-oriented event-driven systems in the context of a case study of a representative application in the supply chain management domain. The methodology, which is based on queueing Petri nets, provides a basis for performance analysis and capacity planning. We study a deployment of the SPECjms2007 standard benchmark on a leading commercial middleware platform. A detailed system model is built in a step-by-step fashion and then used to predict the system performance under various workload and configuration scenarios. After the case study, we present a set of generic performance modeling patterns that can be used as building blocks when modeling message-oriented event-driven systems. The results demonstrate the effectiveness, practicality and accuracy of the proposed modeling and prediction approach.     

用UML描述组件规格说明

在基于组件的软件开放方式（CBD）下，软件系统是一些盯互联系的可重用组件的集合，因此需要对系统的每一个组件以及组件之间的相互关系有很好的理解。UML作为一种标准建模语言，不仅可以支持面向对象的分析与设计，而且能够有力地支持从需求分析开始的软件开发全过程。但是UML对组件建模的支持并不理想，这就需要开发一种能很好支持组件建模的方法。本文提出一种用UML描述组件规格说明的方法。将组件规格说明分解成组件接口规格说明。通过对组件的每个接口和组件接口之间的相互关系加以形式描述，从而达到组件规格说明的清晰性和精确性。