Distributed AEC databases for collaborative design

The Architecture, Engineering and Construction (AEC) design process for a facility involves participation of many design specialists. These participants are architects, engineers (structural, mechanical and electrical) and contractors, who may be independent design professionals or design teams within an organization. From the viewpoint of information processing, two characteristic features distinguish the AEC design process from many other design domains. Firstly, there is a massive volume of design data involved in the design of each of its component specialties. Secondly, the specialization of the disciplines themselves warrant substantial autonomy. For design automation, this autonomy should be realized without sacrificing the collaborative nature of the multidisciplinary AEC design process. We propose autonomous AEC databases to deal with the first issue, and a global constraint maintenance mechanism for the second. Autonomous design databases can support the existing local applications in architectural, structural and mechanical engineering, and construction domains. However, a set of inter-disciplinary constraints needs to be enforced to ensure spatial and functional consistency of the design. A global constraint checking mechanism frees designers from the burden of keeping track of various design changes that may result in cross-functional conflicts. In this paper, we discuss the relevant issues for constraint management on distributed AEC databases. Although specific AEC examples will be used, the presentation is general enough to be applicable to other design domains, such as VLSI and manufacturing.     

一种基于约束管理的CSCW支撑平台结构模型

提出了一种新的基于约束的ＣＳＣＷ支撑系统结构模型，该模型构筑在现有的分布式系统之上，向上提供各种协同功能。现实世界中的各种协同要求从理论上均同象为分布对象之间的一组约束关系，所以可以通过一个″通过约束管理器″即可透明地定义各种对象事件之间的约束关系，形成－协同规则库，并通过该约束管理器的″约束条件触发″，″约束求解（推理）″，″冲突协调″机制便可满足不同层次的协同应用要求。该模型采用了适合于ＣＳＣ     

面向机床产品的协同设计支持环境的研究

对机床产品协同设计过程及其特点进行研究，采用UML统一建模语言中的泳道图表示机床协同设计过程，提出了面向机床产品的协同设计支持环境的层次结构，该协同设计支持环境主要由3个方面的内容组成：对机床产品设计开发活动的支持、对设计活动单元组织和管理的支持、对设计活动单元间协同的支持。采用分布式为主、集中式为辅的方式，建立了面向机床产品的协同设计支持环境的体系结构，并对实现该体系结构的任务规划、协同约束模型、冲突消解等关键技术进行了研究。在此基础上，开发了面向机床产品的协同设计支持环境的原型系统。     

基于UML的图书管理系统的建模过程

UML是一种建模语言,它取代软件界的众多分析和设计方法,已经成为被业界认可的标准建模语言,在软件领域和其他领域都起着举足轻重的作用。UML支持从需求分析、系统设计到具体实现的软件开发全过程。本文通过对图书管理系统的分析,介绍UML的基本概念和建模过程,从而说明UML在实际问题中的应用。     

基于UML的嵌入式软件建模研究

本文以某型嵌入式控制系统软件的设计建模为例,证明了以可视化面向对象的UML建模工具,能够有效克服传统嵌入式系统软件设计中出现的问题,为嵌入式系统软件开发人员提供了一种新的设计开发方法。     

Reasoning about UML/OCL class diagrams using constraint logic programming and formula

Model Driven Engineering promotes the use of models as the main artifacts in software and system development. Verification and validation of models are key activities to ensure the quality of the system under development. This paper presents a framework to reason about the satisfiability of class models described using the Unified Modeling Language (UML). The proposed framework allows us to identify possible design flaws as early as possible in the software development cycle. More specifically, we focus on UML Class Diagrams annotated with Object Constraint Language (OCL) invariants, which are considered to be the main artifacts in Object-Oriented analysis and design for representing the static structure of a system. We use the Constraint Logic programming (CLP) paradigm to reason about UML Class Diagrams modeling foundations. In particular, we use Formula as a model-finding and design space exploration tool. We also present an experimental Eclipse plug-in, which implements our UML model to Formula translation proposal following a Model Driven Architecture (MDA) approach. The proposed framework can be used to reason, validate, and verify UML Class Diagram software designs by checking correctness properties and generating model instances using the model exploration tool Formula.     

Constraint meta-object: a new object model for distributedcollaborative designing

Object databases have been recognized as providing rich data modeling capabilities for the next-generation applications, especially CAD/CAM, software engineering, and multimedia. The core object model consisting of objects, messages and inheritance, however, is not adequate to tackle all the requirements of these applications. Since collaborative activity is one of the key features of next-generation applications, it is essential that the basic object model be extended to support collaborative activity. We propose an object model for collaborative designing based on objects and constraint meta-objects. Each design object has an associated constraint space consisting of one or more constraint meta-objects. The object/constraint meta-object separation achieves a clear distinction between design object and its associated design environment and provides a framework for supporting collaboration among members of a design team. Collaboration is modeled as dependencies among multiple constraint spaces on different nodes, and collaborative activity as design transactions satisfying local constraints and propagating constraints among interrelated constraint spaces. We propose language extensions to C++ for capturing the object/constraint meta-object paradigm. The extensions are implemented using filters, a special mechanism for capturing messages sent to an object. Our model has been applied to the case of a mechanical CAD problem     

Validation of static properties in unified modeling language models for cyber physical systems

Cyber physical systems (CPSs) can be found nowadays in various fields of activity. The increased interest for these systems as evidenced by the large number of applications led to complex research regarding the most suitable methods for design and development. A promising solution for specification, visualization, and documentation of CPSs uses the Object Management Group (OMG) unified modeling language (UML). UML models allow an intuitive approach for embedded systems design, helping end-users to specify the requirements. However, the UML models are represented in an informal language. Therefore, it is difficult to verify the correctness and completeness of a system design. The object constraint language (OCL) was defined to add constraints to UML, but it is deficient in strict notations of mathematics and logic that permits rigorous analysis and reasoning about the specifications. In this paper, we investigated how CPS applications modeled using UML deployment diagrams could be formally expressed and verified. We used Z language constructs and prototype verification system (PVS) as formal verification tools. Considering some relevant case studies presented in the literature, we investigated the opportunity of using this approach for validation of static properties in CPS UML models.     

A distributed and interactive system to integrated design and simulation for collaborative product development

The goal of applying collaborative product development in industry has raised the need to develop software tools supporting system integration and group collaboration. Current methods and tools mainly focus on the collaborative creation of design components and assemblies. However, few of them support the collaborative work in developing simulation models so that proposed design concepts and solutions can be evaluated by integrating expertise from several disciplines. The purpose of this research is to develop a distributed and interactive system on which designers and experts can work together to create, integrate and run simulations for engineering design. To develop such a system, a number of issues, e.g. effectiveness and efficiency of modeling work, the re-use of models, interaction and cooperation, accuracy of simulation, collaborative operation on models, etc., need to be addressed. This paper describes an open architecture to developing simulations for engineering design in a distributed and collaborative environment, identifies a set of key issues raised in this architecture, and presents the techniques employed in our solution.     

Object analysis patterns for embedded systems

Some of the most challenging tasks in building a software system are capturing, refining, and analyzing requirements. How well these tasks are performed significantly impacts the quality of the developed software system. The difficulty of these tasks is greatly exacerbated for the software of embedded systems as these systems are commonly used for critical applications, have to operate reliably for long periods of time, and usually have a high degree of complexity. Current embedded systems software development practice, however, often deals with the (requirements) analysis phase in a superficial manner, instead emphasizing design and implementation. This research investigates how an approach similar to the well-known design patterns, termed object analysis patterns, can be applied in the analysis phase of embedded systems development, prior to design and coding. Specifically, our research explores how object-oriented modeling notations, such as the Unified Modeling Language (UML), can be used to represent structural and behavioral information as part of commonly occurring object analysis patterns. This work also investigates how UML-based conceptual models of embedded systems, based on the diagram templates in the object analysis patterns, can be automatically analyzed using the Spin model checker for adherence to properties specified in linear-time temporal logic (LTL) using a previously developed UML formalization framework. We have applied these patterns to several embedded systems applications obtained from the automotive industry. This paper describes one of our case studies and illustrates how our approach facilitates the construction of UML-based conceptual models of embedded systems and the analysis of these models for adherence to functional requirements.     

Test Synthesis from UML Models of Distributed Software

The object-oriented software development process is increasingly used for the construction of complex distributed systems. In this context, behavior models have long been recognized as the basis for systematic approaches to requirements capture, specification, design, simulation, code generation, testing, and verification. Two complementary approaches for modeling behavior have proven useful in practice: interaction-based modeling (e.g., UML sequence diagrams) and state-based modeling (e.g., UML statecharts). Building on formal V&V techniques, in this article we present a method and a tool for automated synthesis of test cases from scenarios and a state-based design model of the application, remaining entirely within the UML framework. The underlying "on the fly" test synthesis algorithms are based on the input/output labeled transition system formalism, which is particularly appropriate for modeling applications involving asynchronous communication. The method is eminently compatible with classical OO development processes since it can be used to synthesize test cases from the scenarios used in early development stages to model global interactions between actors and components, instead of these test cases being derived manually. We illustrate the system test synthesis process using an air traffic control software example     

On the verification of UML/OCL class diagrams using constraint programming

Assessment of the correctness of software models is a key issue to ensure the quality of the final application. To this end, this paper presents an automatic method for the verification of UML class diagrams extended with OCL constraints. Our method checks compliance of the diagram with respect to several correctness properties including weak and strong satisfiability or absence of constraint redundancies among others. The method works by translating the UML/OCL model into a Constraint Satisfaction Problem (CSP) that is evaluated using state-of-the-art constraint solvers to determine the correctness of the initial model. Our approach is particularly relevant to current MDA and MDD methods where software models are the primary artifacts of the development process and the basis for the (semi-)automatic code-generation of the final application.     

面向方面的时间特性建模

基于面向方面软件设计方法,分离出分布式式系统的时间特性作为一个方面单独建模,将时间子方面思想应用到统一建模语言(UML)建模中,利用随机实时时序逻辑和模糊时间Petri网扩展UML约束。实例证明,该建模方法可解决UML语义问题,使建模更准确,且为日后代码织入、自动生成和测试提供方便。     

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.     

基于UML的嵌入式系统建模及模型验证机制研究

统一建模语言UML在嵌入式系统设计建模中已经获得了广泛的认可,并有很多成功的应用,但UML存在时间约束描述能力不强和所建模型形式化复杂、验证难的问题。针对上述问题,本文提出了使用UML扩展机制对UML状态图进行时间扩展,建立系统状态一约束一事件矩阵来对模型进行形式化描述的方法。该方法解决了UML在嵌入式系统建模时存在的问题。应用实例和实验结果验证了该方法的可行性和有效性。     

Model transformations in the UPES/UPSoC development process for embedded systems

Model-based development (MBD) aims at combining modeling languages with model transformers and code generators. Modeling languages, like profiles of the Unified Modeling Language (UML), are increasingly being adopted for specific domains of interest to alleviate the complexity of platforms and express domain concepts effectively. Moreover, system development processes based on automatic model transformations are widely required to improve the productivity and quality of the developed systems. In this paper, we show how MBD principles and automatic model transformations provide the basis for the unified process for embedded systems (UPES) development process and its unified process for system-on-chip (SoC) (UPSoC) subprocess. They have been defined to foster in a systematic and seamless manner a model-based design methodology based on the UML2 and UML profiles for the C/SystemC programming languages, which we developed to improve the current industrial system design flow in the embedded systems and system-on-chip area. This work is supported in part by the project Model-driven methodologies and techniques for embedded systems design and analysis based on UML, Abstract State Machines, and SystemC at STMicroelectronics, AST R&I of Agrate Brianza (MI), Italy.     

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.     

面向并行程序设计的扩展UML建模

为了解决并行软件开发复杂及维护困难的问题,提出一种并行软件建模的方法。利用统一建模语言(UML)的扩展机制建立了一系列模型,描述了分布式共享内存的基本程序结构建模,通过组合这些基本模型,创建新的模型来适应具体应用。该建模方法保留了UML易理解、易扩展和易于指导工程实践的特点,便于从串行建模扩展到并行建模。通过对一个并行应用的描述,表明该方法对实际的并行程序设计具有指导意义。     

基于UML的SoC建模设计方法研究

随着集成电路制造工艺的发展,嵌入式计算机应用向着SoC的方向发展。为了适应制造工艺对SoC设计能力的要求,提高SoC的设计效率,成为了很紧迫的必要任务。采用统一的SoC系统级建模语言SystemC、软/硬件协同设计技术、基于IP核复用等技术的SoC设计流程,在一定程度上满足了SoC设计要求。在现有SoC设计流程基础上,结合UML的模型驱动框架（MDA）设计方法,在当前的SoC设计流程的系统需求规约描述、硬件实时反应式系统建模、软件模块设计实现中采用UML针对SoC的轻量型扩展特性,可以很大程度地改进提高SoC的设计流程效率。