基于Java/CORBA的Web数据库访问方案

Ｉｎｔｒａｎｅｔ应用程序中,数据库访问技术直接影响到程序的效率,传统的ＣＧＩ和ＡＳＰ技术难以实现高效率的跨平台访问。文章描述了一种基于ＪａｖａＣＯＲＢＡ的分布式Ｗｅｂ数据库访问方案,并以医院信息系统为应用背景,设计实现了基于ａｖａ／ＣＯＲＢＡ的预约挂号Ｗｅｂ数据库访问方案。     

WEB与数据库的连接技术

介绍有关建立Ｗｅｂ数据库的技术,ＣＧＩ,Ｗｅｂ,ＡＰＩ,ＲＡＤ和Ｊａｖａ／ＪＤＢＣ四大类,分析了各类技术的长处和不足。     

WWW与数据库系统信息集成技术

本文讨论了基于ＣＧＩ／ＯＤＢＣ和ＪＡＶＡ／ＪＤＢＣ的数据库访问方法,指出了两种方法的优缺点,并介绍了三大数据库厂商的Ｗｅｂ解决方案。     

基于JDBC的Web数据库应用实现

本文在比较和分析了当前基于 Ｊ Ｄ Ｂ Ｃ 的 Ｗｅｂ 数据库存取方案的基础上,提出了一种自动生成基于 Ｊ Ｄ Ｂ Ｃ 访问数据库的 Ｊａｖａ 小应用程序的思想,设计并实现了基于ｊ Ｃｏｎｎｅｃｔ 的原型系统 Ｄ Ｂ Ａ Ｊ Ａ Ｇ。生成的 Ｊａｖａ 小应用程序使 Ｗｅｂ 浏览器可通过 Ｊ Ｄ Ｂ Ｃ 直接访问数据库,达到较高的效率。     

基于Java技术的Web环境下分布式数据库互操作性的实现

本文首先简要介绍了Ｊａｖａ技术和ＪＤＢＣ和ＲＭＩ机制的工作原理,讨论了如何应用ＪＤＢＣ实现在Ｗｅｂ环境下对异种数据库进行透明访问,如何采用ＲＭＩ机制消除Ｊａｖａ对Ａｐｐｌｅｔ程序的安全性限制,实现Ｗｅｂ环境下分布式数据库的互操作,最后给出了一个我们基于Ｊａｖａ技术设计和实现的Ｗｅｂ环境下Ｎ层Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒ结构分布式数据库应用系统的模型。     

基于Java技术的Web环境下分布式数据库互操作性的实现

应用ＪＤＢＣ在Ｗｅｂ环境下实现对异种数据库进行透明访问及采用ＲＭＩ机制消除Ｊａｖａ对Ａｐｐｌｅｔ程序的安全性限制,实现Ｗｅｂ环境下分布式数据库的互操作,给出了一个基于Ｊａｖａ技术设计实现的Ｗｅｂ环境下Ｎ层Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒ结构分布式数据库应用系统的模型。     

基于Web的分布式计算

随着计算机技术和Ｉｎｔｅｒｎｅｔ／Ｉｎｔｒａｎｅｔ的迅速发展,计算模式发展到Ｗｅｂ上的分布式计算结构,ＷＥＢ技术由静态页面、动态页面发展到实时事务处理,原有的ＣＧＩ、服务器专用ＡＰＩ、ＪＤＢＣ等技术已不能满足要求。提出在ＷＥＢ中引入分布式对象技术,运用ＣＯＲＢＡ、Ｊａｖａ和ＯＯＯＤＢＳ构建一代的Ｗｅｂ的分布式计算体系。     

基于CORBA的PDMS中Web客户端实现

ＰＤＭＳ的发展促使把客户端构架在Ｗｅｂ上。介绍了ＣＯＲＢＡ与ＷＷＷ结合的技术构架;讨论了Ｊａｖａ在ＣＯＲＢＡ与ＷＷＷ结合中的地位和作用。在Ｖｉｓｉｂｒｏｋｅｒ提供的平台上,讨论了Ｗｅｂ客户端的实现方式,并以文档管理为例,描述了Ｗｅｂ客户端具体实现步骤。     

VJ＋＋中DAO的使用

１引言 ＤＡＯ（ＤａｔａＡｃｃｅｓｓＯｂｊｅｃｔ）是Ｊｅｔ数据库引擎的程序设计接口, Ｊｅｔ 引擎是 ＭＳ ＡＣＣＥＳＳ的基础,它也作为 ＯＤＢＣ（ＯｐｅｎＤａｔａＢａｓｅ Ｃｏｎｎｅｃｔｉｏｎ）数据源的数据库驱动程序,同时是一种 ＣＯＭ（Ｃｏｍｐｏｎｅｎｔ Ｏｂｊｅｃｔ　 Ｍｏｄｅｌ）组件。在 ＶＪ＋＋中利用ＤＡＯ可以建立Ｊａｖａ与数据库的连接,并实现对数据库的各种操作ｓ。下面结合例子介绍其原理及实现过程。２实例分析 在开发“基于Ｗｅｂ的编译智能计算机辅助教学系统”的过程中,涉及到对编译领域文法的各种操作…     

应用ASP／ADO技术快速开发动态数据库网页

１引言 高性能的动态网页都离不开后台数据库的支持,无需修改页面设计,网页上发布的信息可随着数据库内容的更新而自动更新。利用 ＡＤＯ （ＡｃｔｉｖｅＸ Ｄａｔａ Ｏｂｊｅｃｔ） 可访问多种支持 ＯＤＢＣ的数据库如 Ｏｒａｃｌｅ、 ＳＱＬ Ｓｅｒｖｅｒ、 Ａｃｃｅｓｓ、 Ｉｎｆｏｒｍｉｘ等。ＡＤＯ集成在ＰＷＳ或ＩＩＳ等操作平台中,执行速度快,易使用,扩展性好。ＡＤＯ与ＡＳＰ结合起来是一种完全的Ｗｅｂ数据库解决方案。 文中首先对ＡＳＰ／ＡＤＱ的工作方式作了简要说明,继而介绍了如何应用 ＡＳＰ／ ＡＤＯ技术快速开发动…     

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).