全相联异构数据集成系统的研究和设计

本文介绍了在建设出入境人员健康状况实时监测网络采用的基于Web Services的全相联异构数据集成方案,该方案利用Web Services的跨平台等特点,综合了数据仓库和虚拟数据库在异构数据集成中的优点,通过设计领域字典表及字段、量纲等映射表,有效地解决了异构数据集成中的环境异构和数据异构等问题,并从异构数据转化、全局查询等方面阐述了该方案的实现过程。实践表明,该方案对了分布式异构数据的共享问题解决具有可行性和高效性。     

Web Services在电力企业信息集成中的应用

分析了电力企业信息化过程中存在的平台系统异构和信息共享困难的问题,介绍了Web Services的核心技术,并结合电力企业生产特殊性和信息管理系统多样性及分散性的特点,提出了一种基于Web Services的电力企业信息集成方案,给出了信息集成构架和三层的信息集成平台结构.该集成方案克服了传统企业应用集成方法的不足,提高了系统的可扩展性和使用性.     

基于Web Services的语义异构数据集成设计与实现

高校在信息化建设过程中积累了大量异构、异质的数据源,如何将这些异构数据源中相关的数据资源进行有效整合是当前急需解决的问题.为此,提出了一种新的基于Web Services的异构数据集成解决方案,利用Web Services技术在异构数据集成中的优势,采用虚拟数据库法设计思想,通过设计领域字典表及字段映射表,有效地解决了异构数据集成中最难解决的语义异构问题,并从数据模型转换、全局查询等方面阐述了该方案的可行性.实验结果表明,该方案具有可用性和高效性.     

基于CORBA 和Web Services 的异构数据源集成研究

为解决信息孤岛问题,提出一个基于CORBA 和Web Servuces 的异构数据源集成的解决方案。讨论了基于CORBA 和Web Services 封装数据源,详细说明了异构数据源集成框架,并介绍了该解决方案的一个应用。     

基于Web Services的企业应用集成模型

Web Services面向服务的体系结构和低成本开发优势使得它的应用变得越来越普及。相对于传统的企业应用集成解决方案,基于Web Services的集成方案能够敏捷和快速地实现异构系统的企业应用集成,它已经成为目前EAI领域的主流。提出了一个基于Web Services的企业应用集成模型,它实现了企业内部、跨互联网的企业间异构系统的松耦合集成。     

基于Web Services的企业应用集成模型

Web Services面向服务的体系结构和低成本开发优势使得它的应用变得越来越普及。相对于传统的企业应用集成解决方案，基于Web Services的集成方案能够敏捷和快速地实现异构系统的企业应用集成，它已经成为目前EAI领域的主流。提出了一个基于Web Services的企业应用集成模型，它实现了企业内部、跨互联网的企业间异构系统的松耦合集成。     

基于Web Services的电子口岸信息系统的集成研究

Web Services是一种面向服务的体系结构，其突出优点是实现了真正意义上的平台独立性和语言独立性。本文系统地分析了Web Services的体系结构和各项关键技术后，提出了以Web Services信息总线为基础的电子口岸信息系统集成方案，并对工作原理进行了研究。该方案可以方便地用于各种已有的口岸异构系统以及新开发的Web Services应用的集成。     

基于Web Services的异构空间信息共享

异构集成技术正日益成为信息资源管理的一个热点技术。以地理信息共享的应用为背景,提出了基于Web Services的异构空间信息共享体系结构。通过引入Web Services技术架构,设计了一个异构空间信息共享系统。该系统可提供各信息源灵活、动态发布自身服务的功能,从而为快速构建异构集成系统提供了性能保证。     

基于Web Services的供应链管理信息集成

介绍了在当前供应链的环境下,成员信息集成交互的重要性,指出了传统的一些分布式信息集成技术的不足,给出了在Web Services技术下供应链信息集成的框架、方案,并指出Web服务的技术优势,在实现异构平台的企业间信息交互的可行性和优点。该方案可以有效的满足供应链信息集成的要求。     

异构组件互操作研究

目前工业级的分布式组件模型有:DCOM,CORBA以及EJB.不同组件模型间缺乏统一的互操作标准,形成了企业内部应用集成和跨企业应用互操作的瓶颈,总结了目前实现异构组件互操作的主要方法并分析了其不足.Web Services的出现为实现异构组件互操作提供了新的契机,提出了基于Web Services的异构组件互操作方案,并以CORBA为例,说明了分布式组件与Web Services的集成.     

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).