基于结构无竞争Petri网的DEDS的状态可达性可控性及其控制

本文给出了依靠代数递推计算判断结构无竞争Ｐｅｔｒｉ网的状态可达性的一种方法；提出了动态子网的概念，提高了判断速度；研究了结构无竞争Ｐｅｔｒｉ网的可达状态控制问题，给出了控制序列的设计方法。     

时序逻辑电路的Petri网分析方法

本文应用带抑止弧的增广Ｐｅｔｒｉ网，建立了基本门电路和常用触发器的Ｐｅｔｒｉ网模型，讨论了运用该模型描述同步和异步时序逻辑电路，给出了增广Ｐｅｔｒｉ网的矩阵描述和状态转移方程，在此基础上提出了同步和异步时序逻辑电路统一分析的Ｐｅｔｒｉ网方法。     

离散事件系统的协调反馈控制

本文探讨以Ｐｅｔｒｉ网为模型的离散事件系统（ＤＥＳ）的某种禁止状态避免问题，提出了以Ｐｅｔｒｉ网Ｎ为基网，设计具有外部输入位置Ｐｅｔｒｉ网（ＰＮＩＰ），对Ｎ进行协调反馈控制的方法。由Ｎ现行状态反馈决定的ＰＮＩＰ的控制状态，既保证Ｎ避免禁止状态，又使Ｎ具有最大自由度。     

模糊Petri网的反馈控制研究

本文首先将模拟技术应用于Ｐｅｔｒｉ网中，得到模糊Ｐｅｔｒｉ网模型，然后基于Ｐｅｔｒｉ网中的库所湾量的概念，在普通Ｐｅｔｒｉ网的反馈控制基础上提出了一种模型Ｐｅｔｒｉ网的反馈控制方法。该方法使得对复杂系统的模糊Ｐｅｔｒｉ多控制器的系统设计成为可能。     

基于Petri网模型的主动对象研究

本文分析了Ｐｅｔｒｉ网及其动态行为特性，扩充了事件、条件、动作等成份的内涵，引入了基于Ｐｅｔｒｉ网事件驱动的主动对象模型，并分析了该主动对象的性质，介绍了主动对象的实现     

基于Retri网的市场需求预测模型研究

市场需求预测问题具有多因素、离散、动态和并发等特点，尤其是并发性始终影响预测结果的稳定性和精度。本文利用Ｐｅｔｒｉ网良好的离散事件动态表达和计算能力以及图形表示的直观性，建立市场需求预测问题的Ｐｅｔｒｉ网模型，并对模型的动态、并发问题进行分析     

模糊Petri网及知识表示

在建造专家系统中虽然有很多种知识表示方法，但都有不尽人意的地方，本文试图用一种新的方法－Ｐｅｔｒｉ网模型来表示知识。本文给出了Ｆｕｚｚｚｙ Ｐｅｔｒｉ网和广义Ｆｕｚｚｙ Ｐｅｔｒｉ网两种模型，并给出了相应的推理算法，一旦专家知识用Ｐｅｔｒｉ网表示后，根据Ｐｅｔｒｉ网固有的特性，我们就能处理专家系统中并行推理、无回溯推理，反向推理等问题。     

计算机网络的Petri网建模及性能指标平估

本文提出了用户广义随机Ｐｅｔｒｉ网理论对计算机网络进行性能指标评估建模的具体规则，并给出了其相应的广义随机Ｐｅｔｒｉ网图，导出了依据广义随机Ｐｅｔｒｉ网模型对计算机网络中几个主要性能指标直接进行计算的议程，克服了以往在建模过程中的盲目性和无规则性。     

双总线结构工业控制计算机网性能指标评估

本文对双总线结构工业控制计算机网给出了其Ｐｅｔｒｉ网和高级Ｐｅｔｒｉ网的建模及性能指标评估方法。文中考虑了信包缓冲区容量有限、信包最大允许服务时间有限、不同的站点优先级和系统总线故障率等因素影响下的网络性能指标评估问题。克服了以往对网络性能评估的某些局限。本文讨论了带计数禁止弧的高级随机Ｐｅｔｒｉ网（ＨＤＳＰＮ）的特性，并对给出的ＤＳＰＮ模型进行了仿真计算，对影响网络性能的系统指标进行了讨论。     

多媒体系统中基于Petri网的同步模型

本文主要介绍了多媒体系统中的媒体同步技术和基于Ｐｅｔｒｉ网的多种同步模型,并讨论了交互式同步模型ＩＳＰＮ。该模型支持用户交互的多媒体同步关系描述,是一种灵活的动态规范。     

C＋＋的this指针和C#的this引用

this在C＋＋中称为this指针，它代表了当前实例的内存地址；在C#中称为this引用：使用this可以在类中方便地访问到本类的当前实例，也可以将本类的当前实例方便地传送到另一个类中去。通过多个例子，说明了在C＋＋和C#中显示或隐含使用this的方法．这些方法是编辑中的常用技巧．     

The Survival of the Fittest and the Reign of the Most Robust: In Biology and Elsewhere

Darwin’s insight that species are mutable, and descent, and origin by means of natural selection is one of the most widely acknowledged strategies for the origin of species and their survival in nature. In his famous contribution, however, Darwin also writes that he is convinced that “... Natural Selection has been the main but not exclusive means of modification” (Darwin in The origin of species. Oxford Univeristy Press, Oxford, p. 7, 1996). This research suggests robustness as another fundamental strategy for survival in nature. The paper does not contradict the popular view, which usually sees robustness as a feature making systems fault-tolerant, thereby focusing on the identification of strategies and techniques for making systems robust (i.e., how to achieve robustness). The paper rather extends this view with an interpretation resting on the question—WHY is robustness omnipresent in the world around us? From this point of view, robustness is interpreted as a fundamental mechanism that is in place because of another fundamental feature in nature—the design and use of sub-optimal systems. The paper argues that, in a sense, nature under-specifies systems but compensates for this by providing systems with various degrees of robustness. We believe that this interpretation may lead to fundamentally new design approaches and insights in several fields.     

TD-LTE与TD-SCDMA切换判决机制的探究与仿真

不同网络之间的切换问题是网络间互操作的重要组成部分,尤其是当前备受关注的TD-LTE与TD-SCDMA的切换问题。该文在对常规切换机制剖析的基础上,通过详尽的理论分析,根据现有切换机制的不足,提出了新的切换判决算法机制。新机制中结合了多属性切换判决中的层次分析算法和二维函数收益法,考虑了移动用户的业务喜好,并使用Matlab搭建了网络模型着重针对数据业务进行仿真,根据不同的网络收益值来实现切换的选择,验证了数据业务切换判决算法的有效性。     

A representation and the norm of Toeplitz operators

The Toeplitz operator has been used in system and control theory for quite a long time. Recently, it played a conspoicuous in H_∞-control theory. One of the important properties of the Toeplitz operator is that its norm is identical to the norm of the Laurent operator with the same symbol. The original proof of this property relies on some advanced tools in operator theory. In this paper, for Toeplitz operators with symbols consisting of an infinite-dimensional stable part and a finite-dimensional unstable part, an elementary and self-contained proof of this property is given. Our proof is based on a representation of the Toeplitz operator presented in this paper and the well known fact that an inner matrix defines an isometry. The representation presented in this paper gives insight into the structure of the Toeplitz operator. A further application of this representation is also presented.     

TINA and the Software Infrastructure of the Telecom Network of the Future

The overall goal of the TelecommunicationsInformation Networking Architecture (TINA) is to defineand specify a software architecture for thetelecommunications infrastructure which encompassesnetworking, network services, and operations, to handle theincreasingly distributed nature of software in networks.The purpose of this paper is to describe how TINA may bepositioned in the software infrastructure of future telecommunications networks, with thefocus on the infrastructures of Public TelecommunicationOperators (PTOs). An architecture for a new PTO networkinfrastructure is proposed and the needs that this architecture satisfies are discussed.The concept of the programmable network isintroduced to satisfy the PTO need to quickly trial anddeploy new services. Five aspects of this targetarchitecture are discussed, namely: a client/serverarchitecture, a service creation architecture, anapplication architecture, a PTO federation architecture,and a new management architecture. The potential role of TINA in each aspect is described, and thepotential benefits of TINA to PTOs aresummarized.     

一种改进的可区分矩阵与求核方法

本文针对Hu方法存在的问题,提出了一种改进的可区分矩阵与求核方法,并证明了该方法的正确性。该方法不仅克服了Hu方法的不足,而且指出了Hu方法出错的根本原因。     

Revisiting the Anatomy and Physiology of the Grid

A domain-specific software architecture (DSSA) represents an effective, generalized, reusable solution to constructing software systems within a given application domain. In this paper, we revisit the widely cited DSSA for the domain of grid computing. We have studied systems in this domain over the last ten years. During this time, we have repeatedly observed that, while individual grid systems are widely used and deemed successful, the grid DSSA is actually underspecified to the point where providing a precise answer regarding what makes a software system a grid system is nearly impossible. Moreover, every one of the existing purported grid technologies actually violates the published grid DSSA. In response to this, based on an analysis of the source code, documentation, and usage of eighteen of the most pervasive grid technologies, we have significantly refined the original grid DSSA. We demonstrate that this DSSA much more closely matches the grid technologies studied. Our refinements allow us to more definitively identify a software system as a grid technology, and distinguish it from software libraries, middleware, and frameworks.     

基于FPGA的压制性干扰源的研究与设计

提出了一种新型压制系统的设计方案,基于现场可编程门阵列作主控,通过直接数字频率合成技术实现中频信号,通过混频的方式进行频谱搬移。系统具有宽带阻塞式、瞄准式和扫频式三种压制方式,且压制带宽和中心频率步进可调。实测结果表明,系统设计符合要求,能够满足实际需要。     

提高频率域可分级视频信源编码效率的研究

在ＭＰＥＧ－２视频编码标准的框架基础上，本文引入了一种提高频率域可分级视频编码效率的方法。通过在８×８ＤＣＴ块中合理地分割系数及尽量减少在低分辨率层中所必需传送的块结束码（ＥＯＢ）的数量，使为获得频率域可分级性所付出的代价明显减小。计算机模拟实验证实了采用该方法可提高编码效率     

CAD与CAE集成过程的分析与建模

文章较详细地分析了CAD产品设计与CAE产品工程分析的集成过程,用 IDEF0对该 CAD设计和CAE工程分析的集成过程进行了建模,所建立的IDEF0模型是建立 CAD、CAE集成信息模型的基础。