模型驱动的嵌入式仿真系统设计

为解决嵌入式系统仿真应用需求多样性的问题并提高系统的开发效率,设计一种通用嵌入式仿真系统。该系统在Matlab/Simulink开发环境的基础上,采用模型驱动的方法设计仿真模型并构建仿真组件库,实现了仿真系统模型的快速建立。同时设计了多接口、可扩展的仿真器硬件结构,解决了嵌入式系统接口的多样性问题。该仿真系统具有良好的可重用性和可移植性等特点,可用于多种嵌入式软件的开发,具有现实意义。     

Generating blogs out of product catalogues: An MDE approach

Blogs can be used as a conduit for customer opinions and, in so doing, building communities around products. We attempt to realise this vision by building blogs out of product catalogues. Unfortunately, the immaturity of blog engines makes this endeavour risky. This paper presents a model-driven approach to face this drawback. This implies the introduction of (meta)models: the catalogue model, based on the standard Open Catalog Format, and blog models, that elaborate on the use of blogs as conduits for virtual communities. Blog models end up being realised through blog engines. Specifically, we focus on two types of engines: a hosted blog platform and a standalone blog platform, both in Blojsom. However, the lack of standards in a broad and constantly evolving blog-engine space, hinders both the portability and the maintainability of the solution. Hence, we resort to the notion of “abstract platform” as a way to depart from the peculiarities of specific blog engines. Additionally, the paper measures the reuse gains brought by MDE in comparison with the manual coding of blogs.     

基于MDA的代码生成器设计与实现

针对如何将业务模型转换为程序代码的问题,提出一种代码生成器设计方案,用以实现模型驱动架构中代码的自动生成。介绍采用XML描述的面向业务对象的平台无关模型,在此基础上设计实现代码生成器,完成从平台无关模型到代码的自动转换,以支持在业务模型变化后系统行为的快速变化和代码的自动生成,通过实例演示该代码生成器的应用。     

基于面向方面MDA的实时系统开发方法

实时系统有许多难以处理的横切整个系统的非功能需求。针对以上问题,提出基于面向方面模型驱动架构的实时系统开发方法。该方法在设计阶段将系统的非功能需求从功能需求中分离出,以降低系统开发的复杂性,提高系统的可重用性、可维护性和横切关注点的模块化程度。通过应用实例证明该方法是有效的。     

Cooperative and competitive concurrency in scientific computing. A full open-source upgrade of the program for dynamical calculations of RHEED intensity oscillations

A computational model is a computer program, which attempts to simulate an abstract model of a particular system. Computational models use enormous calculations and often require supercomputer speed. As personal computers are becoming more and more powerful, more laboratory experiments can be converted into computer models that can be interactively examined by scientists and students without the risk and cost of the actual experiments. The future of programming is concurrent programming. The threaded programming model provides application programmers with a useful abstraction of concurrent execution of multiple tasks. The objective of this release is to address the design of architecture for scientific application, which may execute as multiple threads execution, as well as implementations of the related shared data structures.

New version program summary

Program title: GrowthCPCatalogue identifier: ADVL_v4_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVL_v4_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 32 269No. of bytes in distributed program, including test data, etc.: 8 234 229Distribution format: tar.gzProgramming language: Free Object PascalComputer: multi-core x64-based PCOperating system: Windows XP, Vista, 7Has the code been vectorised or parallelized?: NoRAM: More than 1 GB. The program requires a 32-bit or 64-bit processor to run the generated code. Memory is addressed using 32-bit (on 32-bit processors) or 64-bit (on 64-bit processors with 64-bit addressing) pointers. The amount of addressed memory is limited only by the available amount of virtual memory.Supplementary material: The figures mentioned in the “Summary of revisions” section can be obtained here.Classification: 4.3, 7.2, 6.2, 8, 14External routines: Lazarus [1]Catalogue identifier of previous version: ADVL_v3_0Journal reference of previous version: Comput. Phys. Comm. 181 (2010) 709Does the new version supersede the previous version?: YesNature of problem: Reflection high-energy electron diffraction (RHEED) is an important in-situ analysis technique, which is capable of giving quantitative information about the growth process of thin layers and its control. It can be used to calibrate growth rate, analyze surface morphology, calibrate surface temperature, monitor the arrangement of the surface atoms, and provide information about growth kinetics. Such control allows the development of structures where the electrons can be confined in space, giving quantum wells or even quantum dots. In order to determine the atomic positions of atoms in the first few layers, the RHEED intensity must be measured as a function of the scattering angles and then compared with dynamic calculations. The objective of this release is to address the design of architecture for application that simulates the rocking curves RHEED intensities during hetero-epitaxial growth process of thin films.Solution method: The GrowthCP is a complex numerical model that uses multiple threads for simulation of epitaxial growth of thin layers. This model consists of two transactional parts. The first part is a mathematical model being based on the Runge–Kutta method with adaptive step-size control. The second part represents first-principles of the one-dimensional RHEED computational model. This model is based on solving a one-dimensional Schrödinger equation. Several problems can arise when applications contain a mixture of data access code, numerical code, and presentation code. Such applications are difficult to maintain, because interdependencies between all the components cause strong ripple effects whenever a change is made anywhere. Adding new data views often requires reimplementing a numerical code, which then requires maintenance in multiple places. In order to solve problems of this type, the computational and threading layers of the project have been implemented in the form of one design pattern as a part of Model-View-Controller architecture.Reasons for new version: Responding to the users? feedback the Growth09 project has been upgraded to a standard that allows the carrying out of sample computations of the RHEED intensities for a disordered surface for a wide range of single- and epitaxial hetero-structures. The design pattern on which the project is based has also been improved. It is shown that this model can be effectively used for multithreaded growth simulations of thin epitaxial layers and corresponding RHEED intensities for a wide range of single- and hetero-structures. Responding to the users? feedback the present release has been implemented using a well-documented free compiler [1] not requiring the special configuration and installation additional libraries.Summary of revisions:

• 1. 

  The logical structure of the Growth09 program has been modified according to the scheme showed in Fig. 1.1 The class diagram in Fig. 11 is a static view of the main platform-specific elements of the GrowthCP architecture. Fig. 21 provides a dynamic view by showing the creation and destruction simplistic sequence diagram for the process.

• 2. 

  The program requires the user to provide the appropriate parameters in the form of a knowledge base for the crystal structures under investigation. These parameters are loaded from the parameters.ini files at run-time. Instructions to prepare the .ini files can be found in the new distribution.

• 3. 

  The program enables carrying out different growth models and one-dimensional dynamical RHEED calculations for the fcc lattice with basis of three-atoms, fcc lattice with basis of two-atoms, fcc lattice with single atom basis, Zinc-Blende, Sodium Chloride, and Wurtzite crystalline structures and hetero-structures, but yet the Fourier component of the scattering potential in the TRHEEDCalculations.crystPotUgXXX() procedure can be modified and implemented according to users? specific application requirements. The Fourier component of the scattering potential of the whole crystalline hetero-structures can be determined as a sum of contributions coming from all thin slices of individual atomic layers. To carry out one-dimensional calculations of the scattering potentials, the program uses properly constructed self-consistent procedures.

• 4. 

  Each component of the system shown in Figs. 11 and 21 is fully extendable and can easily be adapted to new changeable requirements. Two essential logical elements of the system, i.e. TGrowthTransaction and TRHEEDCalculations classes, were designed and implemented in this way for them to pass the information to themselves without the need to use the data-exchange files given. In consequence each of them can be independently modified and/or extended. Implementing other types of differential equations and the different algorithm for solving them in the TGrowthTransaction class does not require another implementation of the TRHEEDCalculations class. Similarly, implementing other forms of scattering potential and different algorithm for RHEED calculation stays without the influence on the TGrowthTransaction class construction.

Unusual features: The program is distributed in the form of main project GrowthCP.lpr, with associated files, and should be compiled using Lazarus IDE. The program should be compiled with English/USA regional and language options.Running time: The typical running time is machine and user-parameters dependent.References:

• [1] 

  http://sourceforge.net/projects/lazarus/files/.

     

模型驱动体系结构浅析*

以模型驱动体系结构（ModelDriven Architecture,MDA）的基本概念为切入点,对基于MDA的应用开发过程、MDA的优点、不足及未来作了深入的探讨和思考。     

Lightweight and static verification of UML executable models

Executable models play a key role in many software development methods by facilitating the (semi)automatic implementation/execution of the software system under development. This is possible because executable models promote a complete and fine-grained specification of the system behaviour. In this context, where models are the basis of the whole development process, the quality of the models has a high impact on the final quality of software systems derived from them. Therefore, the existence of methods to verify the correctness of executable models is crucial. Otherwise, the quality of the executable models (and in turn the quality of the final system generated from them) will be compromised. In this paper a lightweight and static verification method to assess the correctness of executable models is proposed. This method allows us to check whether the operations defined as part of the behavioural model are able to be executed without breaking the integrity of the structural model and returns a meaningful feedback that helps repairing the detected inconsistencies.     

一种随机化的软件模型生成方法

模型转换是模型驱动开发的核心技术. 当要把模型转换用于工业生产时, 其性能成为影响这一技术成败的关键因素之一. 为了测试模型转换程序的性能, 需要能够快速地生成一组具有较大规模的模型数据用于作为测试的输入数据. 本文提出一种随机化的模型生成方法. 该方法能够根据元模型的定义以及用户输入的约束条件随机、正确地生成模型文件. 实验结果也表明, 本方法和其它方法相比具有更好的生成效率, 从而更加适合支持模型转换的性能测试.     

Taking context into account in conceptual models using a Model Driven Engineering approach

Context

In public transport, travelers (considered as information systems users) do not have the same objectives and/or concerns at the same time. For this reason it is not always easy to provide them with the right information at the right time. If personalizing the information to the user allows to do this to some extend it is not enough since the information could also depend on the use of the context and the environment (e.g., place, time, etc.).

Objective

This paper proposes a solution allowing the context to be managed inside an application’s conceptual models in order to provide more flexible web applications from the user’s point of view.

Method

Our work is based on a modeling method using the Model Driven Engineering (MDE) approach and on practical field experiences permitting us to validate our solution. Our domain of application is personalized transport information.

Results

Introducing the notion of context into rules and decision trees that are used inside conceptual models allowed us to incorporate context as important information for personalizing web applications.

Conclusion

The context should be integrated into an application during the modeling phase to allow a smooth integration inside the application and to facilitate the evolution over time. Our solution offers a better user’s experience through an extended personalization of web applications.     

模型驱动的测试用例自动生成框架

提出一个基于模型驱动架构(MDA)的测试用例生成框架,其中,平台无关的系统模型通过水平转换成平台无关的测试模型,平台无关的测试模型通过竖直转换生成相应的测试用例。利用MDA转换工具ATL和MOFScript制定相应的转换规则作用于元模型,使测试者只须提供源模型和测试数据即可生成相应的测试用例。