A method for the definition of integrity constraints in object-oriented conceptual modeling languages

We propose a new method that eases the definition of integrity constraints in object-oriented conceptual modeling languages. The essence of the method is to represent constraints by special operations that we call constraint operations. The formal specification of these operations is the definition of the corresponding constraints. The method allows the specialization of constraints and the definition of exceptions. The main application of the method is for static constraints. However, a variant of it can also be applied for creation-time and deletion-time constraints, two particular classes of temporal constraints. The method can be adapted to any object-oriented language, and we show its adaptation to the UML. We also show that our method has several advantages over existing methods.     

Enhancing the semantics of UML association redefinition

Association redefinition is a UML construct that permits us to define an association end more specifically in a particular context. Concretely, it allows specifying some additional participation and cardinality constraints on the association. Association refinements, which have been studied and used by many authors in conceptual modelling languages prior to UML, are closely related to association redefinitions. They also permit to refine the ends of an association adding participation and cardinality constraints. In this paper, we analyze and compare the semantics of both concepts and propose to extend the semantics of association redefinitions in UML to cover all the constraints that may be expressed by association refinements in other conceptual modelling languages. Additionally, we present how to integrate previous results on validation of association refinements to UML and how to generate code for a relational technology platform. Finally, we provide a prototype tool to verify the feasibility of the approach.     

A UML profile for multidimensional modeling in data warehouses

The multidimensional (MD) modeling, which is the foundation of data warehouses (DWs), MD databases, and On-Line Analytical Processing (OLAP) applications, is based on several properties different from those in traditional database modeling. In the past few years, there have been some proposals, providing their own formal and graphical notations, for representing the main MD properties at the conceptual level. However, unfortunately none of them has been accepted as a standard for conceptual MD modeling.

In this paper, we present an extension of the Unified Modeling Language (UML) using a UML profile. This profile is defined by a set of stereotypes, constraints and tagged values to elegantly represent main MD properties at the conceptual level. We make use of the Object Constraint Language (OCL) to specify the constraints attached to the defined stereotypes, thereby avoiding an arbitrary use of these stereotypes. We have based our proposal in UML for two main reasons: (i) UML is a well known standard modeling language known by most database designers, thereby designers can avoid learning a new notation, and (ii) UML can be easily extended so that it can be tailored for a specific domain with concrete peculiarities such as the multidimensional modeling for data warehouses. Moreover, our proposal is Model Driven Architecture (MDA) compliant and we use the Query View Transformation (QVT) approach for an automatic generation of the implementation in a target platform. Throughout the paper, we will describe how to easily accomplish the MD modeling of DWs at the conceptual level. Finally, we show how to use our extension in Rational Rose for MD modeling.     

面向方面的UML建模

为了解决软件开发中建模对于系统级关注点被忽略的问题,提出了面向方面的UML建模模型。对面向方面技术和UML进行全面介绍,使其了解它们的主要构成及参数,并基于AspectJ语言扩展UML中的特征文件(profile),来实现面向方面UML建模(AUML)。该扩展是UML体系的一种扩充,它既结合了UML面向对象的特点,又对面向方面横切关注点在语义和结构上进行了规范。最后就图书管理系统进行举例说明,总结了面向方面软件开发(AOSD)profile的参数。     

一种基于UML的实时工作流建模方法研究

实时系统由于其业务对时间要求的特殊性,使得传统工作流技术难以满足其需求.在传统工作流的基础上,针对实时系统提出了实时工作流的概念,并建立了实时工作流元模型.与传统的工作流相比,主要对工作流的时间约束和异常处理进行了考虑.在活动上扩展了启动时间和执行时间,在工作流过程上扩展了执行时间,在并发活动上扩展了并发时间约束等,此外,元模型中还考虑了活动的超时异常以及应用程序和活动之间的执行关系.为了能够利用实时工作流元模型进行实时工作流建模,通过扩展UML定义了一种实时工作流描述语言,并分别从设计要求、定义技术和profile三个方面对实时工作流描述语言进行了阐述,给出了实时工作流的建模规则.最后结合船舶指控系统的具体实例,对建模方法进行了说明.     

Maintaining constraints of UML models in distributed collaborative environments

Constraint maintenance plays an important role in keeping the integrity and validity of UML models in embedded software design. While constraint maintenance capabilities are reasonably adequate in existing UML modeling applications, little work has been done to address the distributed constraint maintenance issue in multi-user collaborative modeling environments. The nature of the issue is to maintain constraint consistently across distributed sites in a collaborative modeling environment in the face of concurrency. In this paper, we propose a novel solution to this issue, which can retain the effects of all concurrent modeling operations even though they may cause constraint violations. We further contribute a distributed constraint maintenance framework in which the solution is encapsulated as a generic engine that can be mounted in a variety of single-user UML modeling applications to support collaborative UML modeling and distributed constraint maintenance in embedded software design processes. This framework has been implemented in a prototype distributed collaborative UML modeling application CoRSA.     

基于UML的彩色建模技术的研究与应用

建模技术是进行业务系统设计的关键技术。彩色建模技术是在UML建模的基础上,运用色彩进行的可视化建模技术。文中对彩色建模技术进行了介绍和研究,并针对专家在线咨询系统的设计过程,运用彩色建模技术进行了建模的研究工作。介绍了彩色建模的4种常用的模型原型及相应的色彩着色方案,给出了在实践中运用彩色建模技术的实现策略。对于在实践中运用彩色建模技术进行业务系统建模工作具有指导意义。     

An investigation into applying UML to the Zachman framework

The Zachman framework is considered to be the most referenced framework for the purpose of enterprise architecture. It is commonplace to compare other frameworks with this basic one in order to show correctness and usability of those frameworks. However, this is more than a fashion, the Zachman framework is actually the best one. Despite of its popularity, the Zachman framework could be a challengeable one in practical situations because there are not enough well-known methods and tools covering all of its aspects. Three major challenges in using this framework, are discussed in this article. These challenges are lack of a methodology, a well-defined repository and a popular modeling notation. Focus of this article is on solving the last problem with the help of notations in UML (Unified Modeling Language) and UML Business Profile. At the first glance the topic seems to be already researched by others, but there are some major distinctions between this work and the others', which make it a unique one. Most of the other work tried to cover the framework using multiple class diagrams stereotyped in different ways. This work tries to cover the Zachman framework using all of the UML features, especially those, which are convenient in common modeling tools as well as ignoring unfamiliar symobls as it is used by some authors. A case study is used upon which we show how to apply the selected notation on a sample enterprise to develop cells in second and third rows of the framework. Models are tested to consider if they are supporting Zachman rules governing the framework. Furthermore, in order to see if they could be convincing enough, a statistical study is employed. Although results of these tests are relatively acceptable, the problem of inventing new modeling notations is mentioned as an open problem.     

基于UML的面向对象建模研究

本文介绍了UML的基本概念和主要内容,以及UML的建模机制,并结合实例描述了基于UML的面向对象建模过程。     

UML时间顺序图的可达性分析

对于实时系统来说,UML顺序图描述了对象之间的交互。对象之间的交互展现了系统行为的场景。本文中,我们针对描述多场景的UML顺序图组合中的可达性问题进行研究。尽管这个问题可以转换为相应的时间自动机,然后进行处理,但其转化为之后,状态空间巨大,解决的开销比较大,效率不高。针对部分可达性问题,本文采用更为高效的基于线性规划的解决方案,其思想如下:首先遍历所有到达给定节点的简单路径片断来验证可达性,随后遍历到达给定节点的并且包含所有循环至多一次的路径片断来验证可达性。由于我们并没有遍历所有路径片断,因此用本文的方法判定给定节点的可达性的时候,结果会有三种:可达,不可达和不确定。由于有些循环与可达性是无关的,我们进一步通过识别哪些循环与可达性无关,对算法进行改进。     

What do the pictures mean? Guidelines for experimental evaluation of representation fidelity in diagrammatical conceptual modeling techniques

It is important to articulate the objectives and underlying assumptions behind a growing body of experimental research in conceptual modeling. We provide four guidelines for developing materials for experiments that evaluate conceptual modeling techniques, under the assumption that a primary purpose of conceptual modeling is to facilitate communication between analysts and users in validating domain knowledge during systems development. These guidelines assist in developing experimental materials that support meaningful tests of domain semantics. We present empirical evidence indicating the value of two of the guidelines. We also evaluate selected recent experiments on conceptual modeling with respect to the guidelines.     

扩展UML活动图在工作流建模中的应用*

针对UML对数据和信息流描述缺乏充分表达业务工作流程的问题,借助新创建的活动图,提出了基于扩展UML活动图的工作流过程建模方法。应用实例表明,扩展的UML活动图对工作流程的语义表达更丰富,更准确地描述工作流建模所需表达的内容,以满足工作流过程建模的要求。     

Consistency checking and querying in probabilistic databases under integrity constraints

We address the issue of incorporating a particular yet expressive form of integrity constraints (namely, denial constraints) into probabilistic databases. To this aim, we move away from the common way of giving semantics to probabilistic databases, which relies on considering a unique interpretation of the data, and address two fundamental problems: consistency checking and query evaluation. The former consists in verifying whether there is an interpretation which conforms to both the marginal probabilities of the tuples and the integrity constraints. The latter is the problem of answering queries under a “cautious” paradigm, taking into account all interpretations of the data in accordance with the constraints. In this setting, we investigate the complexity of the above-mentioned problems, and identify several tractable cases of practical relevance.     

UML技术在软件可靠性测试中的应用

软件操作剖面的建立是进行软件可靠性测试的基础.介绍了使用UML技术建立软件操作剖面的方法,并结合具体应用实例说明了使用该技术构建软件操作剖面的过程.     

UML及其在图书管理系统中的应用

UML是面向对象的标准化的建模语言,它融入了软件工程领域的新思想、新方法和新技术。文章介绍了UML的主要内容,并以图书管理系统为实例,探讨了基于UML的建模过程。     

带时间约束的UML序列图的分析工具

统一建模语言(UML)是一种多用途的可视化建模语言,它可用于软件系统的规约、可视化的构造和建档.UML序列图描述了交互对象间的协作,如在实时和分布式系统中通讯实体间的信息交互.与其它的规约和设计过程类似,UML序列图的规约也易出错,所以对它进行分析是很有必要的.文章描述了一个对带时间约束的UML序列图进行分析的工具.     

基于UML的MIS开发方法研究

本文对UML的建模机制作了系统的概述,然后以MIS的开发为背景,探索了基于UML的特定应用领域的系统开发方法及UML各图形之间的内在联系,说明了基于UML的系统开发过程是以用例为中心的开发方式。     

扩展UML建模环境中对象关系的模型转换

大量的应用程序采用面向对象的结构,并需要在一个持久化的存储机构———关系数据库中存放和取回数据。面向对象和关系数据库这两种技术存在着阻抗不匹配,使用UML对两种模型进行转换可以减少这种不匹配。但UML对两者的模型转换存在着不足,文中提出了在UML建模环境中引入扩展对象图描述对象和关系的模型转换,简化了模型转换的步骤,使得模型转换的自动化程度更高。     

扩展UML用于面向方面的建模

面向方面编程(AOP)向用户提供了把贯穿特性模块化和编排的能力，以便获得最大的代码重用以及解决代码混乱的问题。然而，目前还没有合适的对AOP的建模语言。文中讨论了一种扩展UML用于面向方面的建模的方法，并通过一个例子来说明这种方法的应用。     

基于UML的概念模型的Petri网映射算法研究

概念模型的动态部分由于其复杂性不易通过阅读式的审查实施验证,针对采用统一建模语言(UML)描述的概念模型,通过UML时序图模型向Petri网模型的映射,可建立Petri网可执行模型,再对其进行验证.在深入分析UML时序图特点的基础上,针对已有映射方法存在的缺点,提出了基于消息的模型映射算法,并对时序图中的特殊结构(可选、条件、并行、循环),分别提出了其相应的映射算法,并验证了映射的正确性.方法有利于检查模型映射前后的一致性,同时具有可扩展的优点.