应用于大规模ASIC的线长驱动的合法化算法

总体布局完成之后的核心任务就是单元位置的合法化,即在将所有的单元安放到布局区并且与合理位置(site)对齐的同时,消除单元间的重叠.为了高效地实现大规模ASIC(Application Specific Integrated Circuit,专用集成电路)的布局过程,提出一种基于线长驱动的合法化算法.它以电路总线长为优化目标,同时考虑单元布局合理位置的约束和预布障碍.在ISPD' 11和DAC' 12竞赛例子上进行的测试结果表明了算法在线长保护及优化方面的效果.这些测试用例都是来源于现代工业ASIC设计的实例,由此说明了算法可以稳定有效地解决工业器中大规模ASIC多种特征电路的布局合法化问题.     

Using meta‐modeling in design and implementation of component‐based systems: the SOFA case study

To allow efficient and user‐friendly development of a component‐based application, component systems have to provide a rather complex development infrastructure, including a tool for component composition, component repository, and a run‐time infrastructure. In this paper, we present and evaluate benefits of using meta‐modeling during the process of defining a component system and also during creation of the development and run‐time infrastructures. Most of the presented arguments are based on a broad practical experience with designing the component systems SOFA and SOFA 2; the former designed in a classical ad hoc ‘manual’ way, whereas the latter with the help of meta‐modeling. Copyright © 2010 John Wiley & Sons, Ltd.     

A framework for developing home automation systems: From requirements to code

This article presents an integrated framework for the development of home automation systems following the model-driven approach. By executing model transformations the environment allows developers to generate executable code for specific platforms. The tools presented in this work help developers to model home automation systems by means of a domain specific language which is later transformed into code for home automation specific platforms. These transformations have been defined by means of graph grammars and template engines extended with traceability capabilities. Our framework also allows the models to be reused for different applications since a catalogue of requirements is provided. This framework enables the development of home automation applications with techniques for improving the quality of both the process and the models obtained. In order to evaluate the benefits of the approach, we conducted a survey among developers that used the framework. The analysis of the outcome of this survey shows which conditions should be fulfilled in order to increase reusability.     

混合监测技术在并行与分布式性能监测中的应用

主要介绍了混合监测技术在并行与分布式系统性能分析评价中的应用。分析比较了常用的几种监测技术,给出了各自的优缺点,介绍了混合监测中的事件的定义,自动装备的过程。事件的采集和分析这向个关键步骤,提出装备的层交化。最后提出了混合监测中会遇到一些问题并给出了相应的解决方法。     

“任务驱动法”在信息技术教学中的运用

"任务驱动法"是建立在建构主义教学理论基础上的教学法,作为建构者——教师,仅是学习的指导者、辅助者、咨询者、导航者,而学生才是教与学活动中的主体,在具体教学过程中,我们应将大量时间留给学生带着驱动"任务"进行研究性学习。目前,我国中学信息技术课程中普遍采用这一教学法,即在具体教学过程中,我们应尽量压缩教师讲授内容的时间,而将大量的时间留给学生进行研究性学习。本文就如何优化信息技术课程谈几点思考。     

Realizing quality improvement through test driven development: results and experiences of four industrial teams

Test-driven development (TDD) is a software development practice that has been used sporadically for decades. With this practice, a software engineer cycles minute-by-minute between writing failing unit tests and writing implementation code to pass those tests. Test-driven development has recently re-emerged as a critical enabling practice of agile software development methodologies. However, little empirical evidence supports or refutes the utility of this practice in an industrial context. Case studies were conducted with three development teams at Microsoft and one at IBM that have adopted TDD. The results of the case studies indicate that the pre-release defect density of the four products decreased between 40% and 90% relative to similar projects that did not use the TDD practice. Subjectively, the teams experienced a 15–35% increase in initial development time after adopting TDD.

Industry evaluation of the Requirements Abstraction Model

Software requirements are often formulated on different levels and hence they are difficult to compare to each other. To address this issue, a model that allows for placing requirements on different levels has been developed. The model supports both abstraction and refinement of requirements, and hence requirements can both be compared with each other and to product strategies. Comparison between requirements will allow for prioritization of requirements, which in many cases is impossible if the requirements are described on different abstraction levels. Comparison to product strategies will enable early and systematic acceptance or dismissal of requirements, minimizing the risk for overloading. This paper presents an industrial evaluation of the model. It has been evaluated in two different companies, and the experiences and findings are presented. It is concluded that the requirements abstraction model provides helpful improvements to the industrial requirements engineering process.

实现事件驱动用户界面规范

本文讨论基于扩充的着色网的事件驱动用户界面规范的实例问题。我们使用扩充的着色网作为对话模型表达互软件的人机交互行为。文中简述了扩充的着色网对话模型,给出 其对象一联系模型及核心算法,最后给出产将扩充的着色网表达的事件驱动用户界面规范转换成可视编程环境的语言程序的方法。     

基于分层递增验证的可信管理软件构造方法

为了保证管理软件在整个生命周期内都具有可信性,在ICEMDA架构基础上融入可信性理论与方 法,提出了一种可信管理软件的模型驱动构造参考方法．通过分析国内外的研究现状,明确界定了管理软件 可信性概念,给出可信性判定问题描述．结果表明该方法以ICEMDA各层次上的构造体为中心,逐层进行可 信模型描述、可信指标度量、可信性判定与优化,借助ICEMDA的模型语义保持技术实现各层间可信性的保 持与传递,并以业务构件PSM模型的可信性判定为例简要介绍了该体系的具体实施机制     

混合关键度驱动的实时调度研究

针对当前运行于不可预测开放环境下的嵌入式多使命复杂关键型系统,需要减少运行成本和处理不可预测工作负载情况的问题,文章提出一种混合关键度驱动的非对称式过载保护最小空闲调度策略。系统过载时,为共享同一处理器的不同关键度任务提供非对称式保护,禁止低关键度任务干扰高关键度任务,完全避免了传统的"关键度反转"问题。在恢复暂时阻塞的不同关键度任务时,在速率单调调度的基础上,引入关键度主导的截止期驱动动态调度策略,可使潜在处理器利用率达到100%。实验结果表明,这种新算法的综合性能优于当前已有的混合关键度任务调度算法。