一种基于J2EE的网络电子期刊系统的设计与实现

文章从分布式多层应用系统的体系结构入手。介绍了一种基于J2EE的网络电子期刊系统的设计思想与实现方法。该方法采用了客户端、应用服务器、数据库服务器的三层体系结构。对网络电子期刊从作者投递到最终稿件发布进行了探讨。     

基于中间件的学生信息检索平台及其Java／Servlet实现

文章介绍了分布式信息检索系统的设计与实现，提出了基于CORBA中间件和Java Servlet的5层Web数据库应用体系结构，实现了基于该体系结构的高校学生信息检索系统CSIRS，并给出了接口定义、Web服务器、CORBA服务器等几个部分的具体设计步骤。     

面向对象建筑工程管理系统的设计与实现

针对建筑工程管理的现实需求和未来发展要求,介绍了一种建筑工程管理系统的设计与实现方法,采用面向对象的软件分析与设计方法,使用UML设计对象,并采用多层体系结构,是面向对象在信息管理系统中的应用.重点介绍系统的解决方案、各模块设计及系统特点.并用JSP和Oracle数据库技术实现了基于分布式体系结构的建筑工程管理系统.     

分布式异构空间数据共享研究

在构建防震减灾WebGIS体系的过程中,引入GML来描述空间数据,设计了空间数据库系统,以实现多源异构数据的共享。系统基于客户层、服务器层和数据库服务器三层体系结构来建造。客户层实现图形用户界面并完成数据的表示。服务器包括Web服务器和GIS应用服务器,前者主要用以客户端通信、后者则要实现对数据库服务器的访问,多源空间数据的获取、转换和输出标准的GML文件等。数据库服务器用来存放本地数据和链接分布式异构数据库。系统采用Java Servlet来完成Web服务器和GIS应用服务器的功能开发,通过Java applet实现客户端、并利用SVG来实现GML数据的可视化。     

带传动远程设计系统的数据流处理方法

针对带传动远程设计系统的开发需求,研究了远程CAD系统中的数据流处理方法.以ASP页面、ADO数据库访问等技术为基础,采用浏览器/服务器/数据库(BWD)的三层体系结构,详细地讨论了带传动远程设计系统中数据输入、输出处理和控制的关键技术及其程序化设计方法.带传动远程设计系统的实现证明本文的方法是可行的,为基于Web的CAD系统提供了有效的数据流处理方法和理论.     

基于.NET仓库管理系统的设计及应用

文中基于.NET平台设计了一个将实现标准库存管理和仓库业务流程的仓库管理系统,实现对捐赠物资、应急物资的数字化、网络化管理.本文阐述了系统的研究目标,及功能架构.并根据研究目标提出设计方案,其中包括系统的结构、硬件的部署和数据库的设计.随后,进行软件的设计和开发.软件主要包括:客户端应用程序开发和服务器端开发.软件开发完成后就系统采用的C/S和B/S两种体系结构,配置服务器,并将程序部署到服务器.最后,系统进行了现场的应用及操作,运行结果表明,系统安全可靠,大大减少了仓库管理的人力物力、和财力,实现了对物资的数字化管理.     

基于SOA的高校人事管理系统的研究

在面向服务体系结构SOA(Service-Oriented Architecture)理念的基础上,设计了基于SOA的高校人事管理系统的体系结构,实现业务层与数据层的多层复用.以业务流程为导向,在分析高校人事管理业务流程的基础上进行服务粒度的设计.最后对该人事系统的Web应用程序的实现进行分析,提出应用JSP和EJB工具,基于MVC模式的实现框架.     

基于嵌入式IP技术的智能监控系统研究

提出了一种通用的基于工业控制、视频和管理自动化相结合的嵌入式远程数字监控系统的设计与实现方法,同时采用高性能服务器管理,网络化的集中监控管理、客户机/服务器体系结构,分布式数据存储和集中的系统管理.介绍了系统结构、软件和硬件构成,其嵌入式结构保证了各种环境及条件下系统的稳定和可靠性,完全是用于各种不同场合的需要.     

变电站综合自动化系统设计

针对变电站的实际运行,设计了基于Web平台上的变电站综合自动化系统三层体系结构.站控层监控主机对变电站进行动态全过程自动监视调节,OPC技术作为监控主机与上层应用程序的通信接口,实现变电站运行设备和数据库服务器之间的数据传输和交换.Web服务器和后台实时数据库实现了变电站运行信息的在线查询和报表处理.     

校园一卡通网络机房系统的设计与实现

本文介绍利用局域网的客户端-服务器数据库操作模式,设计校园一卡通的子系统:网络机房记费与管理系统.该系统充分利用了数据库的远程通信与管理技术,搭建了三层服务器、客户端管理层次模型:客户端-服务器(客户端)-服务器(数据库).介绍了校园一卡通的设计思路,机房管理子系统的开发原理,系统的详细构造,以及数据库系统的维护等.同时分析了在系统实现过程中的一些关键问题,并对此提供了相应的解决方案.     

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。     

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.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).