基于MDA的模型转换研究与应用

模型驱动方法解决了软件开发的效率低、可移植性差等问题,其中的模型转换是开发基于模型驱动构架(MDA)应用工具的关键技术。为此,在模型驱动方法的基础上,提出基于模式的平台无关模型到平台相关模型的模型转换方法,并根据该转换方法确立转换规则,在一个MDA应用系统开发实例中进行验证,实现从平台无关层模型到J2EE平台相关层EJB模型的转换。     

QVT的模型转换方法的研究

模型转换是MDA中最重要的部分之一,其性能的好坏直接影响到软件开发工作的进行.介绍了模型、计算无关模型、平台无关模型、平台相关模型、模型转换和转换规则等的理论知识.其次通过对目前比较流行的直接转换方法、基于关系代数的转换方法和基于元模型间映射的转换方法等模型转换方法的研究,分析了其存在的不足之处,并且提出了QVT的模型转换方法.研究结果表明,文中提出的方法具有很大的性能优势.     

一种基于面向方面机制的模型转换方法

传统对象建模技术生成的PIM(Model Driven Architecture)一般是多重关注点混杂在一起的大型模型,该模型会导致PIM到PSM(Platform Specific Model)的模型转换工作较为困难.提出了一种基于面向方面机制的模型转换方法,该方法在模型层将系统横切关注点与核心关注点分离,单独建模为方面子模型,给出了方面PIM到方面PSM的转换规则,改进了对象建模生成的模型在转换中关注点混杂和对横切关注点管理的不足.     

基于MDA的UML模型转换:从功能模型到实现模型

MDA（Model Drive Architecture）是OMG（Object Management Group）提出的解决系统集成问题的新途径,它以UML、MOF、CWM为核心,定义软件开发过程中的模型组织管理框架。本文探讨了MDA框架下在元模型层定义模型转换的方法。引入模型转换规则描述语言,给出模型转换规则应遵循的部分原则。以CORBA平台为例说明在元模型层用既定语言定义模型转换规则,从功能模型到实现模型的模型转换方法。基于以上方法构建相应的工具原型。     

一种基于有限状态机的模型转换方法

为实现模型的自动转换，通过定义一个清晰的基于规则的模型转换框架，提出了一种基于有限状态机的模型转换方法，用有限状态机技术解决转换规则的实现问题，并定义了适合规则实现机制的形式表示法，然后结合UML模型到SQL模型转换的典型场景，通过一个模型转换示例说明模型转换方法的具体应用，结果表明了该方法的可行性和有效性。该方法适用于状态明显的模型之间的转换，促进了模型自动转换的应用和发展。     

模型驱动架构中的模型转换方法

模型驱动架构是OMG提出的一种新的软件开发方法，模型转换是模型驱动架构中最重要的部分。本文简要讨论了模型转换的概念，并把模型转换方法的结构概括为源模型、目标模型、转换规则库和转换流程控制器四个部分。本文对当前已有的模型转换方法进行了总结和分类，并综合介绍了当前几种主要的模型转换方法，最后对模型转换方法的发展前景做了展望。     

异构三维CAD模型集成转换及共享方法研究*

为解决异构CAD平台间的三维模型转换和共享问题,提出一种新的基于特征模型的集成转换和共享方法。该方法通过集成转换工具实现异构CAD平台的专用模型文件与共享中间文件的转换。首先建立特征模型,分析其信息构成及表达方法;研究了模型文件转换中的关键技术,提出基于CAD平台应用层的几何元素标志方法及标志转换方法;最后设计了集成转换工具的结构模型,并根据该模型编程验证了上述方法的可行性。     

基于有限状态机的模型转换方法的研究

模型转换是MDA框架中最重要的组成部分之一,因此,对模型转换方法的研究非常重要。为了促进MDA框架理论的发展以及探索更有效的模型转换机制,文中对模型转换方法做了较深入的研究。文中通过对有限状态机的分类和有限状态机的工作原理的介绍,并把有限状态机的理论应用到模型转换中,从而提出了基于有限状态机的模型转换方法。文中从以下几个方面对基于有限状态机的模型转换方法进行了较深入的分析与研究,主要包括转换元模型的定义、模型转换中的有限状态机的描述和可逆向操作的状态生成算法。文中提出的方法为有着比较明显的状态变化的模型之间的相互转换提供了一种比较方便的模型转换实施方案,同时对其它模型转换方法也有一定的参考价值。     

面向J2EE主流框架的MDA模型转换研究

提出一种基于元模型和UML Profile的模型转换方法。利用UML Profile来描述基于SSH整合框架系统的PIM和PSM,解决了基本的建模语言不能完整地描述出J2EE主流框架下的平台相关模型的问题。提出了一个能适合SSH整合框架的Web应用层次结构作为PIM元模型,解决元模型间映射规则的复杂、难以匹配的问题。利用基于元模型的模型转换方法制定PIM元模型到PSM元模型的转换规则,间接实现PIM到PSM的模型转换。     

一种支持MDA的模型转换方法

平台无关模型(PIM)到平台有关模型(PSM)的转换是模型驱动体系结构(MDA)中的关键技术，但目前还没有针对该转换的有效的解决方案。从软件工程的实施出发，以抽象代数理论为基础，同时考虑建模元素的语法结构和语义特性，该文提出了一种基于体系结构映射的、可支持模型间自动转换的方法。该方法充分利用软件体系结构在软件开发各阶段间保持的良好可追踪性，使其同时成为系统分析和模型转换的基础。以J2EE目标平台为例说明了该方法的应用。     

Specification-driven model transformation testing

Testing model transformations poses several challenges, among them the automatic generation of appropriate input test models and the specification of oracle functions. Most approaches for the generation of input models ensure a certain coverage of the source meta-model or the transformation implementation code, whereas oracle functions are frequently defined using query or graph languages. However, these two tasks are usually performed independently regardless of their common purpose, and sometimes, there is a gap between the properties exhibited by the generated input models and those considered by the transformations. Recently, we proposed a formal specification language for the declarative formulation of transformation properties (by means of invariants, pre-, and postconditions) from which we generated partial oracle functions used for transformation testing. Here, we extend the usage of our specification language for the automated generation of input test models by SAT solving. The testing process becomes more intentional because the generated models ensure a certain coverage of the transformation requirements. Moreover, we use the same specification to consistently derive both the input test models and the oracle functions. A set of experiments is presented, aimed at measuring the efficacy of our technique.     

一种面向方面的模型转换语言AOMTL*

针对面向方面的PIM到面向方面的PSM的转换,提出了一种面向方面的模型转换语言AOMTL。首先建立方面模型的转换框架;然后根据此框架建立AOMTL的元模型,设计AOMTL的具体语法;最后使用AOMTL完成方面模型转换。该方法为形式化及自动化方面模型转换的描述与实现提供了一种有效的解决办法。     

Search-based model transformation by example

Model transformation (MT) has become an important concern in software engineering. In addition to its role in model-driven development, it is useful in many other situations such as measurement, refactoring, and test-case generation. Roughly speaking, MT aims to derive a target model from a source model by following some rules or principles. So far, the contributions in MT have mostly relied on defining languages to express transformation rules. However, the task of defining, expressing, and maintaining these rules can be difficult, especially for proprietary and non-widely used formalisms. In some situations, companies have accumulated examples from past experiences. Our work starts from these observations to view the transformation problem as one to solve with fragmentary knowledge, i.e. with only examples of source-to-target MTs. Our approach has two main advantages: (1) it always proposes a transformation for a source model, even when rule induction is impossible or difficult to achieve; (2) it is independent from the source and target formalisms; aside from the examples, no extra information is needed. In this context, we propose an optimization-based approach that consists of finding in the examples combinations of transformation fragments that best cover the source model. To that end, we use two strategies based on two search-based algorithms: particle swarm optimization and simulated annealing. The results of validating our approach on industrial projects show that the obtained models are accurate.     

Consistency of model transformation contracts

Model-driven development is a generative software development process with increasing relevance both in industry and academia. Model transformations are the generative components in a model-driven development process. As such, their analysis is an important task. We have been developing a technique to specify, validate and implement model transformations. Our technique is based on the concept of transformation contracts, a specification that relates two modeling languages and declares properties that must be fulfilled in such a relation. Since a transformation contract is a model, the verification and validation of a transformation contract use the same techniques that are used to verify and validate any given model. This paper describes our technique, discusses consistency of model transformations and reports on its application to a non-trivial model transformation from access control models to Java security.     

From model transformation to incremental bidirectional model synchronization

The model-driven software development paradigm requires that appropriate model transformations are applicable in different stages of the development process. The transformations have to consistently propagate changes between the different involved models and thus ensure a proper model synchronization. However, most approaches today do not fully support the requirements for model synchronization and focus only on classical one-way batch-oriented transformations. In this paper, we present our approach for an incremental model transformation which supports model synchronization. Our approach employs the visual, formal, and bidirectional transformation technique of triple graph grammars. Using this declarative specification formalism, we focus on the efficient execution of the transformation rules and how to achieve an incremental model transformation for synchronization purposes. We present an evaluation of our approach and demonstrate that due to the speedup for the incremental processing in the average case even larger models can be tackled.

Graph and model transformation tools for model migration

We describe the results of the Transformation Tool Contest 2010 workshop, in which nine graph and model transformation tools were compared for specifying model migration. The model migration problem—migration of UML activity diagrams from version 1.4 to version 2.2—is non-trivial and practically relevant. The solutions have been compared with respect to several criteria: correctness, conciseness, understandability, appropriateness, maturity and support for extensions to the core migration task. We describe in detail the comparison method, and discuss the strengths and weaknesses of the solutions with a special focus on the differences between graph and model transformation for model migration. The comparison results demonstrate tool and language features that strongly impact the efficacy of solutions, such as support for retyping of model elements. The results are used to motivate an agenda for future model migration research (including suggestions for areas in which the tools need to be further improved).     

基于Atlas语言的数据库模型转换方法的研究

为了减少需求变更对软件开发的影响,提高软件开发效率和系统的可维护性,针对面向对象的数据库建设环节,在MDA思想的基础上,提出了基于元模型的UML模型到数据库模型的自动转换,建立了平台无关模型和平台相关模型的元模型,分析了Atlas的转换语言及其特点.以Web信息管理系统为例,说明了在模型转换中自动化地生成目标模型,并在一定程度上验证了MDA在软件开发中的可行性.     

Incremental execution of rule-based model transformation

When model transformations are used to implement consistency relations between very large models, incrementality plays a cornerstone role in detecting and resolving inconsistencies efficiently when models are updated. Given a directed consistency relation between two models, the problem studied in this work consists in propagating model changes from a source model to a target model in order to ensure consistency while minimizing computational costs. The mechanism that enforces such consistency is called consistency maintainer and, in this context, its scalability is a required non-functional requirement. State-of-the-art model transformation engines with support for incrementality normally rely on an observer pattern for linking model changes, also known as deltas, to the application of model transformation rules, in so-called dependencies, at run time. These model changes can then be propagated along an already executed model transformation. Only a few approaches to model transformation provide domain-specific languages for representing and storing model changes in order to enable their use in asynchronous, event-based execution environments. The principal contribution of this work is the design of a forward change propagation mechanism for incremental execution of model transformations, which decouples dependency tracking from change propagation using two innovations. First, the observer pattern-based model is replaced with dependency injection, decoupling domain models from consistency maintainers. Second, a standardized representation of model changes is reused, enabling interoperability with EMF-compliant tools, both for defining model changes and for processing them asynchronously. This procedure has been implemented in a model transformation engine, whose performance has been evaluated experimentally using the VIATRA CPS benchmark. In the experiments performed, the new transformation engine shows gains in the form of several orders of magnitude in the initial phase of the incremental execution of the benchmark model transformation and change propagation is performed in real time for those model sizes that are processable by other tools and, in addition, is able to process much larger models.

     

结合灰度变换的Chan-Vese模型

幂变换和负片变换是图像增强中频繁使用的两种基本的灰度变换。该文把这两种灰度变换与Chan-Vese模型进行结合,以提高Chan-Vese模型的分割速度和效果。实验表明：该方案大大提高了Chan-Vese模型的收敛速度,而且也使Chan-Vese模型具有较好的处理直线和尖角的能力。