Petri网标记语言

Petri网标记语言(PNML)是一种基于XML语言的Petri网文件交换标准,用于实现Petri网工具的互操作性.综合介绍了 PNML标准化进程和PNML的核心支撑技术,详细阐述了PNML体系结构各个组成部分及元模型中各个组成对象,借助PNK工具实现一个P/T网模型实例,根据元模型分析对应的PNML文件中的库所、变迁和弧等对象标签的含义,最后分析了PNML在工作流模型与矢量图转换等领域的研究状况,指出了下一步研究方向.     

用于WCET静态分析的MIPS处理器建模方法研究

为获得安全而紧致的WCET估计,需要考虑执行程序的目标处理器的体系结构特征．Cache、流水线等用于提高性能的技术已经广泛地应用于现代处理器中,如果在静态分析过程中不考虑它们带来的影响,必然会导致WCET过估计．以Petri网作为模型工具,以WCET分析为应用目标构造MIPS处理器的体系结构模型,该方法讨论了各种RISC处理器中常见的体系结构特征的抽象以及它们在Petri网模型中的表示方法．通过实验验证,指令序列在Petri网模型上的模拟执行时间与指令序列在DLXView模拟器上的测试结果具有一致性,表明构建处理器的体系结构Petri网模型是一种有效的指令序列执行时间的静态分析方法．     

Petri网的符号ZBDD可达树分析技术

Petri网是一种适合于并发系统建模、分析和控制的图形工具.可达树是Petri网分析的典型技术之一,它通过标识向量集合表征系统的状态空间,组合复杂性严重制约了该分析技术可处理系统问题的规模.零压缩决策图(Zero-Suppressed Binary Decision Diagrams,ZBDD)是一种新型的数据结构,是表示和处理稀疏向量集合的一种有效技术.文章基于Petri网町达标识向量的稀疏特征,给出了Petri网分析的符号ZBDD技术,该技术通过对标识向量(状态)的布尔向量表示、可达标识向最(状态)的符号ZBDD生成,实现Petri网可达状态空间的高效符号操作和紧凑符号表示.实验表明,基于ZBDD的符号可达性分析算法能够有效处理较大规模Petri网问题.     

Petri网标记语言

Petri网标记语言（PNML）是一种基于XML语言的Petri网文件交换标准,用于实现Petri网工具的互操作性。综合介绍了PNML标准化进程和PNML的核心支撑技术,详细阐述了PNML体系结构各个组成部分及元模型中各个组成对象,借助PNK工具实现一个P／T网模型实例,根据元模型分析对应的PNML文件中的库所、变迁和弧等对象标签的含义,最后分析了PNML在工作流模型与矢量图转换等领域的研究状况,指出了下一步研究方向。     

基于XML的Petri网信息读写器研究

作为一种优秀的系统描述与分析的形式化工具,Petri网已经广泛应用于协议分析工程领域、人工智能以及软件工程、程序验证和柔性制造系统等各个领域。由于Petri网适合用来描述并发和分布式系统,就目前来说对Petri网的研究已经取得了较成熟的理论研究成果。同时在对Petri网研究的不断深入过程中,出现了多种Petri网类型、各种Petri网工具和Petri网的文件格式,因此不同Petri网工具之间信息交换功能成为一个急需解决的重要问题。     

Petri网的组合积网及性能分析

Petri网是一种系统描述和分析的工具 .Petri网组合是由小系统的性质获得大系统性质的一种有效的分析方法 .本文提出了 Petri网的组合积运算 ,包括 Petri网的 型组合积运算和 型组合积运算、Petri网的并积运算 ,讨论了保持网的结构性质的条件 ,为复杂大系统的分析提供了新途径     

基于可执行模型的体系结构验证评估方法

信息系统体系结构设计是系统开发过程中的一个关键环节,正确评估体系结构能够提高系统开发效率.基于可执行模型的体系结构验证评估方法是一种有效的验证体系结构评估方法.分析基于可执行模型的体系结构验证评估的特点,提出该方法的评估过程和评估内容.提出基于对象Petri网的可执行模型构建方法,并通过实例说明该方法的可行性.     

基于Petri网的自动售货机销售系统建模及验证

提出了一种层次Petri网建立多媒体自动售货机销售系统模型。首先给出了层次Petri网在该系统中的形式化定义及描述,运用分层设计、逐步细化的思想降低系统复杂度,使该系统设计直观、清晰。然后,利用SNOOPY仿真工具和Petri网可达图分别从定性和定量两个方面加以分析,验证了该模型的合理性和有效性。研究表明,层次Petri网是多媒体自动售货机销售系统建模的一种有效途径。     

基于Petri网的工作流建模在群体决策支持系统中的应用研究

Petri网作为一种图形化的建模工具,具有坚实的数学理论基础,是对工作流进行建模和分析的理想工具。通过对网络会商群体决策支持系统的描述,提出了一种基于Petri网的网络会商群体决策系统的工作流模型,并对该模型进行正确性验证,提高了决策支持系统的可靠性和高效性。     

可编程逻辑控制器的平行Petri网设计与实现方法

为了实现可编程逻辑控制器(PLC)的形式化设计, 定义了一种可以感知和执行的新型Petri网, 称为平行Petri 网. 将输入输出变量映射到库所结点上, 描述了PLC的Petri网模型的一般设计方法, 进而给出了其动态演化算法. 通 过C语言和TwinCAT联合编程, 使得Petri网与被控物理对象平行演化, 实现了Petri网对物理过程的平行感知和控制, 并完成了实验验证. 该方法可以缩短控制代码的开发周期, 简化程序复用的复杂性, 为平行系统在PLC工程中的应 用提供了有效工具.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。