基于聚合体的联盟管理服务的实现技术

与传统的分布式仿真运行支撑平台不同,StarLink＋采用层次式体系结构的实现方法。由于层次式体系结构中需要多个RTI服务器在网络上协调一致地为大规模仿真提供服务,因而其实现较其它结构的RTI软件要复杂得多。为降低StarLink＋系统管理的复杂性,支持大规模仿真盟员的加入,论文提出了基于”聚合体”的联盟管理服务的实现思想,并基于该方法具体地描述了各个服务的实现算法。该技术能够大大地降低系统管理的复杂性,从而相应地提高仿真系统的执行效率。     

层次式RTI服务器的设计与实现

提出了基于互操作协议的层次式RTI服务器的设计思想，给出了层次式RTI服务器YH—mRTI的体系结构，在此基础上介绍了YH—mRTI各管理服务的实现技术．由于YH—mRTI中多个RTI可以并行执行，因而可大大提高广域网上大规模仿真的效率．     

层次式RTI中所有权管理的研究与实现

层次式RTI为大规模分布式仿真提供了有效的支撑平台.层次式RTI体系结构中的所有权管理服务,由于其体系结构的复杂性,需要在保证整个系统所有权状态正确一致的前提下,尽量减少局部RTI（LRTI）之间的消息流量,以尽可能快地实现所有权转移.针对以上问题论文提出了各LRTI服务器所有权状态信息的弱一致性思想,即每个LRTI维持的所有权状态信息在LRTI层次上（即属性所有权属于哪个LRTI）保持一致,而在盟员层次上（即属性所有权属于哪个盟员）却可能不一致（以盟员所在的LRTI为准）.这种弱一致性既可以从全局的角度保持所有权状态的正确性, 又可以减少LRTI之间的通信量,高效地实现所有权转移.该思想已应用到层次式RTI软件StarLink＋的实现中,测试表明达到了预期的效果.     

基于兴趣层次的RTI拥塞控制研究

大规模分布式仿真造成数据的爆炸性增长,极大地限制了仿真的规模化和持续性.因为高层体系结构HLA(high level architecture)体系本身固有的缺乏对数据要求级别的定义,RTI(runtime infrastructure)不能充分利用仿真应用的特点进行拥塞控制.兴趣层次描述了不同的接收者对数据的需求差异,提供了一种引入QoS(quality of service)、拥塞控制和层次化数据分发管理DDM(data distribution management)等技术的基础.将兴趣层次理论应用到RTI的运行机制,提出了一种基于兴趣层次的相位过滤算法以进行运行时支撑环境RTI的拥塞控制.实验表明,基于兴趣层次的相位过滤算法对于控制RTI拥塞状况是有效的,同时具有关键数据和传输稳定性的保障.     

HLA/RTI的执行结构与实现研究

高层体系结构(HLA)是新一代计算机仿真的标准,运行支撑环境(RTI)是HLA仿真体系的核心组件,已成为仿真界研究的热点。为了揭示基于HLA/RTI的仿真应用的开发具体实现,了解RTI的本质和精髓,提出了RTI的执行结构框架,揭示了RTI开发的三个对象要素与RTI的六大服务间的关系,并总结出了RTI的三种实现方式,包括集中式、分布式和层次式,对它们各自的特点进行了阐述。     

基于VPN的HLA/RTI交互方案在广域网上的实现

以HLA/RTI为标准的分布仿真网络通信采用多播方式，在广域网环境下，以RTI为通信传输机制的仿真节点间的分布交互难以实现。利用VPN技术在广域网上构建“网上网”，实现广域网条件下仿真节点问的分布交互。同时编程测试了该分布交互方案，结果表明在广域网环境下，使用该方案实现仿真节点间的分布交互是可行的。     

面向服务的高层体系结构研究

针对传统的高层体系结构(HLA)在解决大规模仿真问题所存在的系统的局限性问题,为解决HLA的跨广域网互操作以及联邦成员的动态运行的联接,将面向服务的体系结构(SOA)的思想与HLA相结合,设计了面向服务的运行支撑框架(RTI)分层体系结构,对涉及Web服务提供组件、联邦成员设计等关键技术给出了解决方案,提出了采用语义Web服务的动态建模仿真方法。在实验室环境下通过一个仿真实例进行了测试,结果表明,能够实现HLA向广域网的扩展,并有效支撑仿真服务的动态发现与执行,对于SOA与HLA的结合研究具有一定的参考价值。     

基于网格技术的仿真系统互联与互操作

当前国内基于HLA/RTI开发的大多数仿真系统都是在局域网内构建单联邦,实现联邦内各联邦成员之间的互联与互操作。该文将网格技术与HLA/RTI相结合,实现广域网内多个仿真系统之间的互联与互操作,完成联邦级或系统级的功能共享和重用,并对基于网格技术互联的系统体系结构及关键技术进行了介绍。     

集中式RTI中时间管理的不必要性

本文研究HLA/RTI实现的结构和时间管理之间的关系。当前,人们在为不同的应用构造联盟的过程中设计实现了各种各样的RTI,例如网络多人游戏应用的集中式RTI、国防应用的分布式RTI等。现在,在开发RTI软件的过程中,为了满足IEEE标准且获得所有HLA特征,人们通常在所有RTI中都需要完成时间管理。首先,本文展示了集中式RTI和层次式RTI的结构,解释了时间管理需求的原因。然后,基于基本的结构分析,得出在集中式RTI中并不需要时间管理的结论。最后,本文列举了一些推论,例如层次式RTI的时间管理。     

基于MOM的HLA/RTI管理盟员的设计与实现

为了在仿真运行过程中对联盟、盟员以及RTI进行监控，HLA中引入了管理对象模型(MOM)，该模型是HLA／RTI架构中的重要组成部分。该文介绍了IEEEl516规范中定义的MOM，并在此基础上对其进行了扩展。结合我们StarLink RTI的开发实践，提出了通过代理盟员实现MOM的设计方案，在该RTI中实现了对MOM的支持。最后在此基础上，设计并实现了管理盟员StarFM。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.