基于梯度博弈的RFID室内定位算法

随着普适计算的不断发展,室内定位技术成为了当今研究的热点问题。室内空间的复杂性使得室内空间的定位精度一直无法满足应用的需求。为了获得更加高效稳定的算法,提出了一种基于梯度和博弈论的室内定位算法,其能够较为有效地提高室内空间的定位精度。在算法中,提出了一种室内的符号划分方法,并利用其对室内空间进行了分割以辅助定位算法。最后以室内为实验环境对算法进行了验证,分析结果表明,该算法拥有良好的定位效果,并且相对于现有算法更稳定。     

基于感知规则集策略的约束空间RFID室内符号定位算法

随着普适计算的不断发展,室内定位技术的研究也成为当今研究的热点问题。室内定位技术的不断进步使得RFID也开始部署到各种各样的室内场景。为了提高室内空间中的定位精度,提出了一种基于感知规则集策略的约束空间RFID室内符号定位方法。算法基于室内空间中的符号,通过定义感知情况来确立定位规则,使得算法具有良好的室内空间适应性,且使用少量的阅读器即可实现较高精度的定位。为了提高定位精度,引入了感知规则集的概念,对场景中的情况抽象提取,进一步增加算法定位精度。最后,以约束空间中的室内场景作为实验环境对算法进行验证,分析结果表明,在室内空间中算法的定位精度及抗干扰能力优于现有算法。     

基于改进支持向量机的Wi-Fi室内定位算法

针对室内复杂环境下无线信号不稳定、传统支持向量机定位算法计算复杂度高等难题,为了提高室内的定位精度,提出一种改进支持向量机的Wi-Fi室内定位算法。采用核主成分分析对特征进行降维处理,提取有用信息、降低计算量,采用支持向量机构建定位特征与物理位置的非线性映射模型,并采用粒子群算法对模型参数进行优化,进行了仿真实验。结果表明,该算法提高了室内定位精度和效率。     

三维空间RFID定位系统方法及其应用研究

为了提高室内定位系统的性能, 提出了一种三维空间内利用RFID技术定位目标物体的算法。算法通过接收信号强度获得天线和目标标签之间的距离, 然后采用梯度下降法计算得到目标电子标签的位置。仓库定位网络实验结果显示, 所建立的算法可以逐步逼近目标标签的真实位置, 有效提高了三维空间内目标的定位精度, 在仓库管理等室内定位系统中具有较强的实用性。     

基于权重参数实时更新的室内定位算法

为了提高室内节点的定位精度,提出一种基于权值参数实时更新的室内定位算法。选择3个最能反映待定位点信息的访问接入点,实时获取测距模型的参数,并采用最小二乘支持向量机对测距进行补偿,得到距离权重,三边定位算法根据权重对节点进行定位,并对计算中的距离进行加权处理,采用卡尔曼滤波法对定位误差的进行校正。实验结果表明,该算法可以较好地降低环境变化和测量误差对定位的不利影响,提高了室内节点的定位精度。     

基于无线传感器网络的自适应声源定位算法

基于声源能量的无线传感器网络（ WSNs）最大似然定位算法抗噪声干扰能力强,定位精度高,同时适用于多个目标定位,但是计算量大,不适用于实时定位。针对现有算法的缺点,提出了一种基于自适应迭代的最大似然定位算法。该算法将代价函数作为目标函数,在给定的梯度误差范围内自适应地搜索目标位置。为了提高算法的收敛速度和定位精度,提出了基于Sigmoid函数的变步长的搜索算法。仿真实验结果表明：与最大似然定位算法相比,自适应迭代算法运算量小,定位精度高,能满足对目标定位精度和速度要求较高的场合,具有一定的实际应用意义。     

基于XGBoost的客户所在店铺WiFi定位技术研究

为了减小室内复杂环境等因素对WiFi定位的影响,降低定位成本,提高定位精度并缩小定位区域,通过对室内定位系统和相关机器学习算法进行深入分析和探讨,提出了一种基于XGBoost的WiFi室内定位算法。根据WiFi信号强度分布不均匀的特点,此算法通过提取WiFi强度特征,并利用XGBoost分类器对信号来源进行定位。实验结果表明,该定位算法在WiFi强度特征可检测时达到了87.72%的定位精度,达到预期的定位效果,同时定位时间较短,稳定性较好,可以基本满足实时定位的要求。     

一种改进的室内无线定位算法

为提高室内无线定位精度并降低算法复杂度,提出一种改进的室内无线定位算法,包含2种分支算法。以视距路径数为标准,将室内无线环境划分为非视距污染较轻和较重2种环境。对污染较轻的环境,采用改进的Fang-Taylor级联算法;对污染较重的环境,采用新的迭代定位算法。仿真实验结果表明,该算法能达到甚至超过同类算法的定位精度,且适应多种室内无线环境,提高对环境的鲁棒性。     

信号强度与运动传感器融合的智能手机室内定位算法

利用智能手机传感器实现高精度跟踪定位已经成为一个研究热点,本文针对室内定位中由于手机的运动引起采集信号强度不稳定造成的定位误差大的问题,提出了基于信号强度与加速度梯度融合综合的新的测距算法,结合手机方向信息、地图信息、信号强度的分布信息,利用测距信息与地图匹配算法,实现对智能手机的精确定位。在实验测试中,该算法平均定位精度为1.2m, 3.5m以下定位精度达95%。本算法有效的提高了智能手机的室内定位精度,并且相比指纹库定位算法减少了搜索次数,提高了定位速度。     

基于UWB的LSM-Taylor级联车辆定位算法

为了满足智能车在室内的高精度定位要求,针对室内的伪三维定位场景,提出了一种基于超宽带(Ultra Wideband,UWB)的LSM-Taylor级联车辆定位算法.该算法以到达时间差(Time Difference of Ar-rival,TDOA)为定位方式,以多基站最小二乘法(Least Square Method,LSM)定位算法的计算结果为初始值,通过Taylor级数迭代估计车辆的精确位置.该算法主要解决多径效应和非视距产生的测量误差对定位精度的影响,从而提高定位精度.在仿真结果中,相比LSM定位算法,LSM-Taylor级联定位算法的定位结果分布更加紧密,定位精度更高.实际测试结果表明,该定位算法的均方根误差(Root Mean Squared Error,RMSE)在10 cm以下,能满足智能驾驶中的室内定位要求,验证了该方法的有效性.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.