基于信誉度效益最优的网格调度算法研究

基于经济模型的网格调度算法是目前网格环境中非常重要的算法,而信誉度是经济模型的一个概念.文中将信誉度问题引入到网格资源分配中,通过信誉度与效益相结合,提出了基于信誉度的网格资源分配算法.将信誉度融入到网格资源调度中,用户可以选择信誉度高的资源,提高了资源的信誉度,同时使得网格资源的质量有所提高.通过实验对算法进行了验证.实验结果表明,在费用和时间限制相同的情况下,该算法在使网格资源获得效益上优于时间最优化算法和代价最优化算法,并且提高了资源调度的效率.     

一种新的经济网格计算任务调度控制模型

针对动态计算网格资源调度问题,基于多智能体协同技术和市场博弈机制,对计算网格资源分配技术进行了深入研究,提出了基于计算经济的网格资源调度模型,设计了消费者的效用函数,讨论了资源分配博弈中Nash 均衡解,设计了一种网格资源调度算法.仿真实验表明,资源调度算法能够为消费者的资源数量提供参考,规范消费者行为,从而使得整个资源的分配趋于合理,促进交易量.     

基于通信代价的网格资源调度算法

针对基于时间和预算限制的资源调度算法在调度数据密集型应用程序时存在的问题,提出一种新的基于通信代价的网格资源调度算法,综合考虑用户的时问限制和预算要求,根据用户作业的计算量与通信量选择具有一定计算能力,且通信代价较小的资源节点作为目标节点,通过减少此类程序提交到目标资源节点的通信代价,达到减少整个应用程序完成时间的目的。实验结果表明,该算法能够获得较好的性能。     

基于MAS市场机制的动态计算资源调度模型研究

针对动态计算网格资源调度问题,结合多Agent系统(multi agent syste,MAS)协同技术和市场竞价博弈机制,对计算网格资源分配技术进行了深入研究,提出了能够反映供求关系的基于市场经济的网格资源调度模型,该模型一方面能够充分利用消费者Agent的协商能力,另一方面能够充分考虑消费者的行为,使得消费者的资源申请和分配具有较高的合理性和有效性.同时,设计了消费者的效用函数,论证了资源分配博弈中Nash均衡点的存在性和惟一性以及Nash均衡解.基于所提资源调度模型,设计了一种网格资源调度算法.仿真实验表明,资源调度算法能够为消费者的资源数量提供参考,规范消费者竞价,从而使得整个资源的分配趋于合理.     

模糊选择消费代价函数动态资源分配算法研究

主要研究了资源分配基数,提出了一种新的基于选择消费代价网格资源分配算法。提出的方法首先采用模糊基数建立一个消费代价函数模型,给出了网络中带权值的多参数消费代价函数。实例验证表明,当用户需要从系统中获得资源时,采用该方法在网格规模非常大而且计算量较小的情况下,选择代价最小的方法给用户使用来分配资源,具有一定的实际应用价值。     

基于MAS协同的动态资源优化调度策略研究*

目前,围绕着网格中的资源调度方法,虽然已提出了各种调度算法,但是都不能很好地适应网格环境下的自治性、动态性、分布性和异构性等特征。针对动态计算网格资源调度问题,基于多智能体协同技术和市场博弈机制,对计算网格资源分配技术进行了深入研究,提出了能够反映供求关系的基于计算经济机制的网格资源调度模型,建立了消费者的效用函数,给出了资源调度的动态博弈算法。仿真实验说明资源利用率比传统算法好,整个资源的供需合理、负载均衡。     

基于竞争机制的网格资源分配方法

针对在网格环境下对资源进行有效管理和调度的复杂性问题,提出一个基于竞争机制的网格资源分配模型,其中包括用户层、代理层及资源层。在该模型的基础上给出资源分配策略及一种费用优化算法。模拟实验表明,该模型能够较好地适应网格环境的动态变化,调整供给和需求的平衡。     

一种基于市场机制的计算网格资源分配方法

针对计算网格提出了一种基于市场机制的资源分配方法，以一般均衡理论为基础，依靠市场机制，实现计算网格资源的优化分配，首先，描述了基于代理的资源分配框架，它包括3个 层次：资源层、代理层和用户层；接着，给出了计算网络资源分配的市场模型，其中效用函数用于刻画用户对给定资源的满意程度；然后定义了市场模型的均衡状态并证明了均衡状态撮优性，这意味着在均衡状态下资源分配不仅有效而且公平，最后引入了资源代理的迭代算法。     

异构蜂窝网络中功率和资源分配博弈算法研究

基于D2D和中继异构蜂窝网络进行资源复用可获得系统性能增益,但同时也使得网络中的干扰更加复杂。针对该问题,提出功率和资源分配博弈（PRAG）算法,通过功率控制和资源分配对D2D和中继异构蜂窝网络进行干扰协调。基于代价参数设定D2D和中继链路效用函数,确定最佳发射功率。在此基础上,将生成的效用值矩阵参与博弈,选择合适的蜂窝用户进行资源复用。仿真结果表明,与等功率分配随机（EPAR）算法相比,PRAG算法能够在消耗更少功率的基础上获得更大的系统吞吐量。     

计算网格资源分配研究

计算网格是一种新的技术,有很多内容都刚开始研究发展,还不成熟。由于网格资源的异构与时变,网格资源用户的不同需求,使网格资源分配成为一个重要问题。因而,网格资源分配技术也成为一种关键技术。给出了基于代理的网格资源分配策略和资源代理的迭代算法,从而实现了资源的协调分配。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.