ZigBee无线传感器网络管理的应用研究

无线网络技术和计算机科学技术的飞速发展,各种尖端技术被人们所关注。ZigBee是一种新兴的、自组织、低功耗、低数据速率的近程无线网络通信技术,随着ZigBee技术的不断改进、成熟,更显现出在学校管理系统中的强大优势。详细分析了ZigBee无线传感器网络技术以及在校园管理中的应用。     

基于NFC技术的巡更巡检管理系统的设计与实现

为解决传统电子巡更技术无法兼备便捷性和实时性的问题,设计并实现一种基于近距离通信(near filed communication,NFC)技术的巡更巡检管理系统。融合智能移动终端NFC技术和移动通信技术,通过Android终端触碰NFC标签采集巡更信息,使用移动通信技术上传巡更信息至Web后台。APP前端采用Google Android平台开发,Web后台采用Java Servlet与JSP开发,结合MySQL进行数据库管理。实例验证了NFC巡更巡检管理系统的可行性,为电子巡更系统兼备便捷性和实时性提供解决方案。     

基于近场通信的移动客户端防伪溯源系统设计

设计一个基于NFC技术的防伪溯源系统,该系统分为NFC防伪溯源标签、移动客户端和后台管理系统.通过介绍NFC技术的基本原理,给出了NFC技术的基础架构,得出在防伪溯源方面,NFC技术与传统防伪溯源系统相比的优势.然后研究了NFC在移动客户端的通信方式,结合加密算法来实现防伪溯源功能.后台管理系统则是为商家提供商品管理,物流信息查看等功能.该系统对当前的家禽、畜牧等产业有一定的应用价值.     

基于NFC技术的智能考勤管理系统设计与实现

针对目前高校教学考勤效率低、管理混乱的问题,设计并实现了一种近距离通信(NFC,near field communication)智能考勤管理系统.该系统基于智能移动终端的NFC技术,结合SQLite数据库,使用Google Android开发平台.分析了系统架构及功能模块具体设计,阐述了系统基于Android的实现方法.通过实验测试,得到系统平均读卡识别率约为99.89％.实验结果表明,NFC智能考勤管理系统可使考勤管理更为高效、准确.     

基于ZigBee技术的计算机机房监控系统

介绍一种基于无线传感器网络技术和校园局域网的高校机房远程监控管理系统。系统通过传感器对计算机机房环境数据进行采集,通过ZigBee网络和基于以太网的校园局域网将数据上传至监控中心,实现对机房环境状态的监测和管理,保障机房运行的可靠性。     

基于物联网技术的公共自行车租赁管理系统

随着公共自行车或为城市公共交通的重要组成部分,融合射频识别技术、无线通信、计算机网络等物联网技术,设计一种感应式公共自行车租赁系统,每个自行车租赁点都能提供24小时自助服务,降低了系统的建设和运营成本,提高了租借的效率,而且增强了自行车的安全管理。该系统主要分为车俩感知模块和业务管理系统模块两大部分,系统操作简单,方便了用户的使用。     

基于NFC技术的校园支付应用创新研究

首先讨论了移动支付的概念、发展历史以及应用形式,并对移动支付体系进行深度研究;其次,讲述了NFC技术的概念、发展现状和应用场景;最后,将NFC融入移动电子商务中的移动支付体系中,分析了NFC技术在校园支付中的应用,针对校园的特殊场景进行应用分析,以便为未来NFC技术在移动电子商务近距离支付的相关研究提供帮助与推进作用。     

基于GIS技术的校园设施管理系统

结合重庆邮电学院设施管理系统开发的实践经验，介绍了一种将GIS技术应用到校园设施管理系统中的方法。详细阐述了校园设施管理系统的体系结构、软硬件环境、功能结构及空间数据库的设计方法。     

基于ZigBee的学生智能管理系统设计与实现

针对传统有线校园智能管理系统存在的布线成本昂贵、无法在移动载体上读取,且虚拟局域网存在的安全性、灵活性等问题,比较现有的几种无线通信方式,提出一种基于ZigBee技术的校园智能管理实施方案．．洋细设计了以CC2430为核心的通信节点硬件电路和节点的软件流程,扩展了针对于校园管理的节点应用,完成了系统管理软件的开发。进行了点对点的节点通信实验,结果表明：增加了功率放大器和低噪声放大器的通信节点满足校园管理的信息传输需求设计,方案具有可行性。     

基于C#和ASP的校园公用自行车管理系统设计与实现

讲述了校园公用自行车管理系统的设计与实现过程,为高校公用自行车的管理提供一个有效的管理方法。系统基于C#和ASP开发,使用SQL Server数据库,实现了对自行车、学生和管理员信息的添加、删除、修改等基本操作。     

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).