可复用MOF元建模框架的研究*

在MDA场景下,元模型是实现平台无关模型和平台相关模型转换的核心。提出通过元层模型和模型层模型的DownUp机制给出可复用的MOF元建模框架。元建模框架由MOF BootStrap模型自举,并且内置MOF Model,此框架可在任意多层元建模中复用。此外,给出了模型工程模型和模型迁移剪枝算法,并提出了采用模型工程统一对象空间实现模型实例复用的方法。此框架的研究对于指导具体建模工具的实现有重要意义。     

基于构件技术的应用框架元模型的研究

从应用框架构造和组成的角度,使用UML(unified modeling language,统一建模语言)符号体系,提出了框架元模型,给出了框架内部组成元素的语义,特别是对扩展点的表示和实现机制进行了详细的讨论.最后以电信综合营业系统框架为例,给出了框架元模型的一个实例,并给出了应用框架的复用方法.     

基于元元模型的多维元数据管理研究与实现

分析了目前元数据管理的研究现状和存在的问题;按照OMG的MOF规范,建立了统一的MOF元元模型,对不同领域的元模型进行统一描述;提出了一个高度可集成可扩展的元数据管理框架和元模型建模规范;介绍了主题与元模型的相容约束规则以及主题与元数据的访问约束规则;通过采用对元数据按主题进行动态分类的方式,实现了对元数据的多维管理.     

UML模型到N层Web模型的模型驱动转换

模型驱动架构(MDA)是由对象管理组织(OMG)提出的应用模型技术进行软件开发的方法和标准体系,其核心理念是平台无关模型建模和平台特定模型转换。通过编程实现基于元对象机制2.0(MOF2.0)查询/视图/转换(QVT)标准定义开发的框架,该框架可以将元模型转换为特定N层应用程序类,实现主要程序功能,从而大大提高开发效率。验证了通过编程实现模型驱动转换的灵活性和功能实现的多样性,包括XML文件对模型规范的描述以及生成代码的完整性。     

支持CMMI的软件过程元模型的研究与实现

为解决软件组织在软件项目开发过程中难以实施CMMI(capability maturity model integration)过程改进的问题,基于模型驱动架构的思想和技术,提出了一种"裁剪+重型扩展+轻型扩展"的元模型建模策略.给出了该建模策略下的具体实施步骤和方法,实现了一种支持CMMI过程改进的软件过程元建模,同时给出了基于该元模型的建模实例.实验结果表明,该元模型有助于软件组织建立体现其组织特征并有效支持符合CMMI框架的软件过程用户模型.     

ERP系统的组件化模型研究

对ERP系统的组件化进行了研究，提出了ERP系统的组件化模型框架，该模型框架由企业视图层、系统构架层、生命周期层3个维度组成。企业视图维给出了组件化的企业对象，系统构架维给出了ERP系统的组件化层次，生命周期维给出了组件化的实施过程。从软件复用的角度对模型框架进行了详细阐述。     

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。     

基于MDA的设计模式建模与模型转换

MDA(model driven architecture)的一个重要意图是将模型作为软件开发的基本单元,以进一步提高软件开发的抽象层次.为此,MDA划分了3种抽象级的模型,并通过建立高抽象级的模型和向低抽象级模型及代码的转换来构造可运行的应用程序.在MDA的框架下,将设计模式作为一种独立的建模和转换单元能够在较高的抽象层次上充分支持复用并提高建模粒度,从而进一步发挥设计模式的优点,提高软件开发效率、降低生产成本.然而,要在MDA的框架下将设计模式作为完整的开发单元来使用,必须解决以模式为单元的建模及转换两个具体问题.针对单元化模式建模的问题,通过扩展MOF(meta object facility)的方式定义了模式单元元模型,并提供了基于此元模型的单元化建模支撑机制,以分离业务模型与模式模型的方式解决了该问题.针对单元化模式模型转换问题,在模式单元元模型的基础上定义了向EJB平台的转换规则.该转换规则使用QVT标准描述,支持单元化的模式模型转换,并具有良好的复用性.     

面向服务的本体元建模理论与方法研究

为实现互联网上异种异构的复杂信息资源有序化组织和互操作性服务与共享的目标。文章研究了语义服务的元计算问题。提出了本体元建模理论和方法．首先定义了本体UML承诺、提倡本体UML表达。给出了本体的元机制;论述了元建模中的“元”概念。给出了元层次停止准则、模型转换机制;然后提出了本体建模和MOF元模型设施相融合的体系结构,给出了以用户为中心的复杂信息资源服务应用模式SCDL为本体元建模方法的体系化提供了基础．还介绍了作者在国际ISO SC32标准MMFI for Ontology Registry研究中的应用成果．最后给出了HL7领域本体与元模型设计的应用．本体元建模为语义服务计算的实现。提供了一条可行的路径．     

扩展Java元模型以实现诠释的可视化建模

诠释（annotation）是JavaSE5引入的一种新的编程语言成分，目前得到广泛关注。但从可视化建模来看，已有的Java元模型和UML2元模型并不支持诠释规范，这导致诠释的语义特征在高层抽象中难以体现，也不能实现诠释的可视化、规范化建模。本文扩展已有的Java元模型，以支持诠释的可视化建模。文章提出了诠释的4个重要特征，添加了3个元类以扩展Java元模型，使其能反映诠释特征，并给出2个图符以支持诠释的可视化建模。新的Java元模型符合MOF规范，设计简单，方便实现以支持MDA及相关工具的开发。     

A Meta-Modeling Approach for Autonomous Driving Scenario Based on STTD

In the current autonomous driving scenario modeling and simulation field, autonomous driving modeling driven by Spatio-Temporal Trajectory Data (STTD) is a key problem, which is significant to improve the safety of the system. In recent years, great progress has been achieved in the modeling and application of STTD, and the application of this data in specific fields has attracted wide attention. However, because STTD has diversity and complexity as well as massive, heterogeneous, dynamic characteristics, the research in the safety-critical field modeling still faces challenges, including unified metadata of spatio-temporal trajectories, meta-modeling methods based on STTD, data processing based on the data analysis of spatio-temporal trajectories, and data quality evaluation. In view of the modeling requirements in the field of autonomous driving, a meta-modeling approach is proposed to construct spatio-temporal trajectory metadata based on Meta Object Facility (MOF) meta-modeling system. According to the characteristics of spatio-temporal trajectory data and autonomous driving domain knowledge, a meta-model of spatio-temporal trajectory data is constructed. Then, we study the modeling approach of autonomous driving safety-critical scenarios based on the spatio-temporal trajectory data meta-modeling technology system, use the modeling language ADSML for automatic instantiation of safety-critical scenarios, and construct a library of safety-critical scenarios, aiming to provide a feasible approach for the modeling of such safety-critical scenarios. Combined with the scenarios of lane changing and overtaking, the effectiveness of the meta-modeling method for autonomous driving safety scenarios driven by spatio-temporal trajectory data is demonstrated, which lays a solid foundation for the construction, simulation, and analysis of the model.     

A recommendation system for meta-modeling: A meta-learning based approach

Various meta-modeling techniques have been developed to replace computationally expensive simulation models. The performance of these meta-modeling techniques on different models is varied which makes existing model selection/recommendation approaches (e.g., trial-and-error, ensemble) problematic. To address these research gaps, we propose a general meta-modeling recommendation system using meta-learning which can automate the meta-modeling recommendation process by intelligently adapting the learning bias to problem characterizations. The proposed intelligent recommendation system includes four modules: (1) problem module, (2) meta-feature module which includes a comprehensive set of meta-features to characterize the geometrical properties of problems, (3) meta-learner module which compares the performance of instance-based and model-based learning approaches for optimal framework design, and (4) performance evaluation module which introduces two criteria, Spearman's ranking correlation coefficient and hit ratio, to evaluate the system on the accuracy of model ranking prediction and the precision of the best model recommendation, respectively. To further improve the performance of meta-learning for meta-modeling recommendation, different types of feature reduction techniques, including singular value decomposition, stepwise regression and ReliefF, are studied. Experiments show that our proposed framework is able to achieve 94% correlation on model rankings, and a 91% hit ratio on best model recommendation. Moreover, the computational cost of meta-modeling recommendation is significantly reduced from an order of minutes to seconds compared to traditional trial-and-error and ensemble process. The proposed framework can significantly advance the research in meta-modeling recommendation, and can be applied for data-driven system modeling.     

Resampling methods for meta-model validation with recommendations for evolutionary computation

Meta-modeling has become a crucial tool in solving expensive optimization problems. Much of the work in the past has focused on finding a good regression method to model the fitness function. Examples include classical linear regression, splines, neural networks, Kriging and support vector regression. This paper specifically draws attention to the fact that assessing model accuracy is a crucial aspect in the meta-modeling framework. Resampling strategies such as cross-validation, subsampling, bootstrapping, and nested resampling are prominent methods for model validation and are systematically discussed with respect to possible pitfalls, shortcomings, and specific features. A survey of meta-modeling techniques within evolutionary optimization is provided. In addition, practical examples illustrating some of the pitfalls associated with model selection and performance assessment are presented. Finally, recommendations are given for choosing a model validation technique for a particular setting.     

对象约束语言及其在精化PIM中的应用

为了应用精确、完备的PIM自动进行模型转换、校验及编译,分析了OCL元模型与UML元模型间的关系,在此基础上对OCL在精确化平台无关模型(PIM)方面的应用进行了研究,指出OCL面临的挑战,并对OCL的研究方向提出了几点建议。对象约束语言OCL可以对模型中的元素进行约束和查询,可以在MOF的任意一层上定义模型语言,还可以通过各种方法定义模型的转换规则。     

元建模在电子商务开发平台中的研究与应用

为了提高电子商务系统开发效率,通过元建模机制提出一种电子商务开发的建模语言——EBP建模语言。EBP建模语言在UML上进行扩展,添加了MVC模式的电子商务元数据及SQL建模结构,实现了元数据的支撑框架,适用于支持模型驱动的网站开发和数据库应用。开发人员通过建模和设置元数据值,可获得应用框架与程序代码,快速有效地构建电子商务系统。     

时空轨迹数据驱动的自动驾驶场景元建模方法

时空轨迹数据驱动的汽车自动驾驶场景建模,是当前汽车自动驾驶领域中驾驶场景建模、仿真所面临的关键问题,对于提高系统的安全性具有重要研究意义.近年来,随着时空轨迹数据建模及应用研究的快速发展,时空轨迹数据应用于特定领域建模的研究引起人们的广泛关注.但由于时空轨迹数据所反映现实世界的多元性和复杂性以及时空轨迹数据的海量、异构、动态等特点,基于时空轨迹数据驱动的安全攸关场景建模的研究仍面临着挑战,包括：统一的时空轨迹数据元模型、基于时空轨迹数据的元建模方法、基于数据分析技术的时空轨迹数据处理、数据质量评价等.针对汽车自动驾驶领域的场景建模需求,我们提出一种基于MOF元建模体系构建时空轨迹数据的元建模方法,根据时空轨迹数据的特征及自动驾驶的领域知识,构建了面向汽车自动驾驶的时空轨迹数据元模型;并基于此,提出基于时空轨迹数据元建模技术体系的自动驾驶安全场景建模方法,并使用场景建模语言ADSML实例化安全场景,构建安全场景库,旨在为此类系统的安全关键场景建模提供一种可行的方案.结合变道超车场景的案例,展示了时空轨迹数据驱动的自动驾驶安全场景元建模方法的可用性,为场景模型的构建、仿真、分析奠定了基础.     

Web应用开发平台的元建模研究

传统的Web应用开发方法面临系统复杂度增加、需求不断变更等挑战，导致开发效率低下，系统难重用。本文基于MDA方法学，采用标准建模语言UML和元建模语言MOF，定义了针对Web应用的面向对象建模语言UML-EBP。通过分析UML-EBP元模型结构、语义以及相关模型实例的表述，表明UML-EBP元模型可以很好地应用于Web应用系统开发过程，从而快捷简便地实现Web应用系统开发，并使得系统容易扩展、复用。     

An algebraic semantics for MOF

In model-driven development, software artifacts are represented as models in order to improve productivity, quality, and cost effectiveness. In this area, the meta-object facility (MOF) standard plays a crucial role as a generic framework within which a wide range of modeling languages can be defined. The MOF standard aims at offering a good basis for model-driven development, providing some of the building concepts that are needed: what is a model, what is a metamodel, what is reflection in the MOF framework, and so on. However, most of these concepts are not yet fully formally defined in the current MOF standard. In this paper we define a reflective, algebraic, executable framework for precise metamodeling based on membership equational logic (mel) that supports the MOF standard. Our framework provides a formal semantics of the following notions: metamodel, model, and conformance of a model to its metamodel. Furthermore, by using the Maude language, which directly supports mel specifications, this formal semantics is executable. This executable semantics has been integrated within the Eclipse modeling framework as a plugin tool called MOMENT2. In this way, formal analyses, such as semantic consistency checks, model checking of invariants and LTL model checking, become available within Eclipse to provide formal support for model-driven development processes.     

The OsMoSys approach to multi-formalism modeling of systems

Analysis and simulation of complex systems are facilitated by the availability of appropriate modeling formalisms and tools. In many cases, no single analysis and modeling method can successfully cope with all aspects of a complex system: a multi-formalism multi-solution approach is very appealing, since it offers the possibility of applying the most suitable formalisms and solution techniques to model and analyze different components or aspects of a system. Another important feature that a successfull modeling approach should include is the possibility of reusing (sub)models: by composing parameterized submodels and then instantiating the parameters, complete models of different scenarios can be obtained and analyzed.This paper introduces an innovative approach to multi-formalism modeling of systems that is part of the OsMoSys (Object-based multi-formaliSm MOdeling of SYStems) framework. OsMoSys uses the proposed modeling approach to build multi-formalism models, and workflow management to achieve multi-solution. Our modeling approach is based on meta-modeling, allowing to easily define and integrate different formalisms, and on some concepts from object orientation. Its main objectives are the interoperability of different formalisms and the definition of mechanisms to guarantee the flexibility and the scalability of the modeling framework.