UML类图层次化自动布图算法

UML类图能够有效地帮助软件工程师理解大规模的软件系统,而优化图元的空间布局可以增强类图的可读性和可理解性.由于类图中继承关系具有明显的层次特性,因此类图自动布局大多采用层次化的布图算法.此外,类图布局需要考虑相关的领域知识以及绘制准则,因而通用嵌套有向图层次化布局算法不能直接用于类图的绘制,它们必须加以扩展.但是,已有的类图层次化方法并没有考虑类图中图元的嵌套关系,这将导致自动布局方法不能处理类图中包与类、接口之间的包含关系.在考虑图绘制美学、UML类图绘制以及软件可视化等相关知识的基础上,选取了一组布     

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。     

一种UML类图的复杂性和可复用性度量方法

UML类图描述了系统中的类及其相互之间的各种静态关系,为了对UML类图提供客观的评价,通过对典型度量方法的改进,文章采用一组度量从不同侧面来评价一个类图的复杂性和可复用性,并考虑了类图中属性和方法在公有、私有和受保护性质方面的区别。     

Using formal metamodels to check consistency of functional views in information systems specification

UML notations require adaptation for applications such as Information Systems (IS). Thus we have defined IS-UML. The purpose of this article is twofold. First, we propose an extension to this language to deal with functional aspects of IS. We use two views to specify IS transactions: the first one is defined as a combination of behavioural UML diagrams (collaboration and state diagrams), and the second one is based on the definition of specific classes of an extended class diagram. The final objective of the article is to consider consistency issues between the various diagrams of an IS-UML specification. In common with other UML languages, we use a metamodel to define IS-UML. We use class diagrams to summarize the metamodel structure and a formal language, B, for the full metamodel. This allows us to formally express consistency checks and mapping rules between specific metamodel concepts.     

基于动态切片和UML图的回归测试用例生成

针对基于UML设计的面向对象软件在修改后进行回归测试的情况,提出一种回归测试用例生成的新方法。获取软件修改后进行回归测试时必须重新测试的类和方法,分析与需要重测试类有关的UML顺序图,对顺序图中每个包含不等关系的条件断言生成与其有关的动态程序切片,根据该动态程序切片生成与其相应的回归测试用例。     

基于UML图和不同粒度切片的回归测试研究

针对面向对象软件回归测试的新特点,本文引入了基于UML图的不同粒度切片。首先,对描述类间关系的UML类图和描述状态变迁关系的UML状态图形式化定义。接着,对定义的图进行切片分析,其中类间测试提出一种基于UML类图的粗粒度切片工具;类内测试提出一种基于UML状态图细粒度切片的方法。最后,将其应用于销售订单系统,结果表明以上两种分析方法可以有效地提高回归测试效率。     

一种从UML模型到可靠性分析模型的转换方法

以构件化的软件开发方法为背景,提出了一种将UML模型自动地转换为可靠性分析模型Markov链的方法.该方法基于构件化的软件体系结构,从UML的用况图、顺序图、活动图和构件图出发,对其进行扩展,在模型中标注了可靠性分析所需的信息.在此基础上,通过构造一个称为构件转移图的中间模型,将标注了可靠性信息的UML模型转换为Markov链.该方法产生的结果能够直接作为现有可靠性相关的数学分析方法的输入,从而使可靠性分析工作变得更加方便、高效.     

Validating timed UML models by simulation and verification

This paper presents a technique and a tool for model-checking operational (design level) UML models based on a mapping to a model of communicating extended timed automata. The target language of the mapping is the IF format, for which existing model-checking and simulation tools can be used. Our approach takes into consideration most of the structural and behavioural features of UML, including object-oriented aspects. It handles the combination of operations, state machines, inheritance and polymorphism, with a particular semantic profile for communication and concurrency. We adopt a UML profile that includes extensions for expressing timing. The breadth of concepts covered by our mapping is an important point, as many previous approaches for applying formal validation to UML put much stronger limitations on the considered models. For expressing properties about models, a formalism called UML observers is defined in this paper. Observers reuse existing concepts like classes and state machines, and they allow expressing a significant class of linear temporal properties. The approach is implemented in a tool that imports UML models from an XMI repository, thus supporting several editors like Rational Rose, Rhapsody or Argo. The generated IF models may be simulated and verified via an interface that presents feedback in the vocabulary of the original UML model. This work has been partially supported by the OMEGA European Project (IST-33522). See also http://www-omega.imag.fr     

Synthesizing object life cycles from business process models

Unified modeling language (UML) activity diagrams can model the flow of stateful business objects among activities, implicitly specifying the life cycles of those objects. The actual object life cycles are typically expressed in UML state machines. The implicit life cycles in UML activity diagrams need to be discovered in order to derive the actual object life cycles or to check the consistency with an existing life cycle. This paper presents an automated approach for synthesizing a UML state machine modeling the life cycle of an object that occurs in different states in a UML activity diagram. The generated state machines can contain parallelism, loops, and cross-synchronization. The approach makes life cycles that have been modeled implicitly in activity diagrams explicit. The synthesis approach has been implemented using a graph transformation tool and has been applied in several case studies.     

信息系统UML建模研究

UML作为一种面向对象的标准建模语言,在信息管理系统的建模领域得到了广泛的应用.概述了UML中多种模型图的使用方法和适用范围,分析了UML系统建模的主要过程和特点,并以一个实验预约系统为例详细介绍了系统用例模型,静态模型和动态模型的设计过程,同时重点探讨了在一般信息系统建模过程中普遍适用的系统类筛选、动态方法定义等相关技术.     

Empirical studies concerning the maintenance of UML diagrams and their use in the maintenance of code: A systematic mapping study

ContextThe Unified Modelling Language (UML) has, after ten years, become established as the de facto standard for the modelling of object-oriented software systems. It is therefore relevant to investigate whether its use is important as regards the costs involved in its implantation in industry being worthwhile.MethodWe have carried out a systematic mapping study to collect the empirical studies published in order to discover “What is the current existing empirical evidence with regard to the use of UML diagrams in source code maintenance and the maintenance of the UML diagrams themselves?ResultsWe found 38 papers, which contained 63 experiments and 3 case studies.ConclusionAlthough there is common belief that the use of UML is beneficial for source code maintenance, since the quality of the modifications is greater when UML diagrams are available, only 3 papers concerning this issue have been published. Most research (60 empirical studies) concerns the maintainability and comprehensibility of the UML diagrams themselves which form part of the system’s documentation, since it is assumed that they may influence source code maintainability, although this has not been empirically validated. Moreover, the generalizability of the majority of the experiments is questionable given the material, tasks and subjects used. There is thus a need for more experiments and case studies to be performed in industrial contexts, i.e., with real systems and using maintenance tasks conducted by practitioners under real conditions that truly show the utility of UML diagrams in maintaining code, and that the fact that a diagram is more comprehensible or modifiable influences the maintainability of the code itself. This utility should also be studied from the viewpoint of cost and productivity, and the consistent and simultaneous maintenance of diagrams and code must also be considered in future empirical studies.     

Visualizing Design Patterns in Their Applications and Compositions

Design patterns are generic design solutions that can be applied and composed in different applications where pattern-related information is generally implicit in the Unified Modeling Language (UML) diagrams of the applications. It is unclear in which pattern instances each modeling element, such as class, attribute, and operation, participates. It is hard for a designer to find the design patterns used in an application design. Consequently, the benefits of design patterns are compromised because designers cannot communicate with each other in terms of the design patterns they used and their design decisions and trade-offs. In this paper, we present a UML profile that defines new stereotypes, tagged values, and constraints for tracing design patterns in UML diagrams. These new stereotypes and tagged values are attached to a modeling element to explicitly represent the role the modeling element plays in a design pattern so that the user can identify the pattern in a UML diagram. Based on this profile, we also develop a Web service (tool) for explicitly visualizing design patterns in UML diagrams. With this service, users are able to visualize design patterns in their applications and compositions because pattern-related information can be dynamically displayed. A real-world case study and a comparative experiment with existing approaches are conducted to evaluate our approach.     

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.     

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.     

Automatic extraction of OWL ontologies from UML class diagrams: a semantics-preserving approach

Full implementation of the Semantic Web requires widespread availability of OWL ontologies. Manual ontology development using current OWL editors remains a tedious and cumbersome task that requires significant understanding of the new ontology language and can easily result in a knowledge acquisition bottleneck. On the other hand, abundant domain knowledge has been specified by existing database schemata such as UML class diagrams. Thus developing an automatic tool for extracting OWL ontologies from existing UML class diagrams is helpful to Web ontology development. In this paper we propose an automatic, semantics-preserving approach for extracting OWL ontologies from existing UML class diagrams. This approach establishes a precise conceptual correspondence between UML and OWL through a semantics-preserving schema translation algorithm. The experiments with our implemented prototype tool, UML2OWL, show that the proposed approach is effective and a fully automatic ontology extraction is achievable. The proposed approach and tool will facilitate the development of Web ontologies and the realization of semantic interoperations between existing Web database applications and the Semantic Web.     

Extending interaction overview diagrams with activity diagram constructs

UML2.0 introduced interaction overview diagrams (IODs) as a way of specifying relationships between UML interactions. IODs are a variant of activity diagrams that show control flow between a set of interactions. The nodes in an IOD are either inline interactions or references to an interaction. A number of recent papers have defined a formal semantics for IODs. These are restricted, however, to interactions that can be specified using basic sequence diagrams. This excludes the many rich modeling constructs available in activity diagrams such as interruptible regions, activity groups, concurrent node executions, and flow final nodes. It is non-trivial to allow such constructs in IODs because their meaning has to be interpreted in the context of interaction sequences rather than activities. In this paper, we consider how some of these activity diagram constructs can be used practically in IODs. We motivate the integration of these constructs into IODs using a NASA air traffic control subsystem and define a formal semantics for these constructs that builds on an existing semantics definition for IODs.     

UML模型驱动的划分测试用例生成方法研究

测试用例的自动生成是软件测试研究的主要方向之一。针对现有的UML模型驱动测试方法在测试数据生成方面存在低效、无目的性、冗余等问题,提出了基于UML活动图模型驱动的划分测试用例自动生成方法。该方法将测试场景归为五种类型,并为每种类型规划了测试数据取值范围和选择方法。构建了基于该方法的原型工具软件,提供被测软件原模型和数据约束即可生成测试用例。实验结果表明,该方法能够在不降低测试覆盖率的情况下,能生成数量少、针对性强的测试用例集。     

Graphic Language for Describing Constraints on Diagrams of UML Classes

A visual notation for specifying constraints on diagrams of UML classes by means of the UML collaboration diagrams is suggested. A formal semantics of the suggested notation is presented.     

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。     

UML状态图的测试用例自动生成

现有的研究在对UML状态图生成测试用例时,为简化问题而忽略了对伪状态的支持。针对这一问题,首先对UML状态图的伪状态概念进行分析,并讨论了其对相关测试用例生成算法的影响;改进了UMLstatechart语义对伪状态的定义,对伪状态进行适当的转换,同时扩充现有算法对伪状态的支持;提出了一套可以处理伪状态的UML状态图平坦化算法以及相应的测试用例生成方法,并对实际应用效果进行了验证。