基于Matlab的光纤电流传感器温度补偿研究

针对光纤电流传感器存在温度稳定性的问题,文章提出了一种基于Matlab的光纤传感器温度补偿的设计方案。该方案根据光纤电流传感器的输出偏差值,结合Matlab的曲线拟合功能,进行最小二乘法四次多项式拟合,找出温度补偿因子,从而建立温度补偿方程。实验结果表明,该光纤电流传感器测得的电流值的最大误差由温度补偿前的13.35%降低到温度补偿后的0.3%,大大提高了光纤电流传感器的精度和温度稳定性。     

光纤传感器桥式补偿技术的实用性研究

本文对桥式补偿结构在光纤传感器中的应用进行了深入的研究，其补偿效果的优劣主要取决于补偿结构的稳定性，用这种补偿技术的光纤压力传感器系统计量油罐贮量得到优于０．２％的长期稳定性，把这种结构使用在激光雷达光纤传感器系统中同样取得显著的补偿效果。     

分布式光纤拉曼测温系统信噪比优化研究

针对分布式光纤拉曼测温系统(ROTDR)信噪比较低的问题,在传统累加平均算法的基础上,提出利用小波包去噪以及埃尔米特插值算法对后向拉曼散射信号进行处理来提升系统信噪比。该方法首先在数据采集端对散射信号进行累加平均去噪,然后使用埃尔米特插值算法进行色散补偿,最后选取sym6小波基对散射信号进行小波包去噪处理。实验表明,该方法将系统信噪比由27.6159 dB提升至32.6988 dB,而且有效补偿了系统的色散效应。选取8 km光纤进行实验,光纤全程温度波动范围从0.65℃~1.15℃降低至0.36℃~0.75℃,不同温度的测量误差中位数小于0.5℃。综上,本文提出的信号处理方案可有效提升系统信噪比及降低系统测温误差。     

不同调制技术下光纤链路色散与补偿方案分析

该文首先对色散进行了较全面的概述,提出并分析各项光纤参数对通信系统的影响。简单的说明了色散补偿的原理,介绍了不同调制技术下光纤链路色散补偿技术,进而将该方法进行多方面的比较分析,展望色散补偿研究前景。     

具有闭环系统的法拉第电流传感器

利用法拉第效应建立了一种偏振结构的电流传感器，它具有闭环反馈系统，从输出端反馈的电流信号驱动偏振调制螺线管产生补偿信号使传感器工作在正交状态，这样就有效地消除了费德尔常数变化给传感器带来的误差．该传感器线性测量范围是：1mA～6．5A。     

应变和温度同时测量光纤光栅传感器的研究

光纤光栅的出现给一直停滞不前的光纤传感领域带来了新的生机 ,但解决应变、温度的交叉敏感问题 ,实现应变、温度的同时测量一直是光纤光栅传感器的关键问题。从其产生机理出发 ,分析讨论了国内外解决此问题的最新进展 ,并提出了一种新颖的应变、温度光纤光栅传感器系统     

基于MAX1457的传感器智能化温度补偿的实现

MAX1457是一种专用传感器信号处理器,它可以补偿硅压阻式传感器的温度误差和非线性误差,使传感器总的重复性精度达到0．2％以内。MAX1457对传感器进行温度补偿时需要经过一系列操作步骤和参数的选择计算。本文分析了MAX1457的工作原理和补偿过程。在此基础上开发的温度补偿软件,可以实现参数的自动计算,自动调整,补偿的每一个操作步骤均辅以向导式的提示。该系统的使用使得MAX1457对传感器的温度补偿过程大为简化。     

微型航姿系统中磁传感器温度漂移补偿研究

研究了微型航姿系统中地磁传感器的温度特性,根据地磁传感器噪声的频谱特性,设计了带阻数字滤波器;基于地磁传感器测量原理分析传感器输出电压随温度变化的规律,利用多项式相消的方法建立磁传感器温度漂移误差的实时补偿模型,并应用于微型航姿系统的磁航向解算。多次试验结果表明:地磁传感器零偏模型具有良好的重复性,实时温度漂移误差补偿模型可以有效地补偿地磁传感器引起的温度漂移误差;缩短了系统的预热时间,提高了系统输出的磁航向精度。     

常规光纤非线性对色散补偿光纤位置的影响

通过数值计算的方法分析了色散、自相位调制和激光器啁啾等因素对１０Ｇｂ／ｓ１００ｋｍＧ．６５２光纤通信系统的综合效应。对１０Ｇｂ／ｓＧ．６５２光纤系统中用色散补偿光纤（Ｄｉｓｐｅｒｓｉｏｎ Ｃｏｍｐｅｎｓａｔｉｏｎ Ｆｉｂｅｒ,即ＤＳＦ）的两种方案进行了比较,然后简单讨论了色散补偿光纤在密集波分复用（ＤＷＤＭ）中的应用,最后给出通过以上分析得出的结论。     

应变和温度同时测量光纤光栅传感器的研究

光纤光栅的出现给一直停滞不前的光纤传感领域带来了新的生机,但解决应变、温度的交叉敏感问题,实现应变、温度的同时测量一直是光纤光栅传感器的关键问题.从其产生机理出发,分析讨论了国内外解决此问题的最新进展,并提出了一种新颖的应变、温度光纤光栅传感器系统.     

INTRODUCTION TO THE SPECIAL ISSUE ON CASE-BASED REASONING IN THE HEALTH SCIENCES

There has been an explosion of interest in health sciences applications of case-based reasoning (CBR), not only in the traditional CBR in medicine domain, but also in bioinformatics, enabling home health-care technologies, CBR integration, and synergies between CBR and knowledge discovery. This special issue features the best papers from the third workshop on CBR in the health sciences, held at ICCBR-05 in Madrid. It is the third in a series of exciting workshops, the first two of which were held at ICCBR-03, in Trondheim, Norway, and at ECCBR-04, in Madrid, Spain. The nine high-quality papers introduced here represent the research and experience of twenty-two authors working in eight different countries on a wide range of problems and projects. These papers illustrate some of the major trends of current research in CBR in the health sciences, and represent overall an excellent sample of the most recent advances of CBR in the health sciences.     

The Old-Age Healthy Dependency Ratio in Europe

The aim of this study is to answer the question of whether improvements in the health of the elderly in European countries could compensate for population ageing on the supply side of the labour market. We propose a state-of-health-specific (additive) decomposition of the old-age dependency ratio into an old-age healthy dependency ratio and an old-age unhealthy dependency ratio in order to participate in a discussion of the significance of changes in population health to compensate for the ageing of the labour force. Applying the proposed indicators to the Eurostat's population projection for the years 2010-2050, and assuming there will be equal improvements in life expectancy and healthy life expectancy at birth, we discuss various scenarios concerning future of the European labour force. While improvements in population health are anticipated during the years 2010-2050, the growth in the number of elderly people in Europe may be expected to lead to a rise in both healthy and unhealthy dependency ratios. The healthy dependency ratio is, however, projected to make up the greater part of the old-age dependency ratio. In the European countries in 2006, the value of the old-age dependency ratio was 25. But in the year 2050, with a positive migration balance over the years 2010-2050, there would be 18 elderly people in poor health plus 34 in good health per 100 people in the current working age range of 15-64. In the scenarios developed in this study, we demonstrate that improvements in health and progress in preventing disability will not, by themselves, compensate for the ageing of the workforce. However, coupled with a positive migration balance, at the level and with the age structure assumed in the Eurostat's population projections, these developments could ease the effect of population ageing on the supply side of the European labour market.     

Stability of nonlinear hybrid dynamical systems with time delay via sum of squares decomposition

Considering an infinite number of eigenvalues for time delay systems, it is difficult to determine their stability. We have developed a new approach for the stability test of time delay nonlinear hybrid systems. Construction of Lyapunov functions for hybrid systems is generally a difficult task, but once these functions are found, stability’s analysis of the system is straight-forward. In this paper both delay-independent and delay-dependent stability tests are proposed, based on the construction of appropriate Lyapunov-Krasovskii functionals. The methodology is based on the sum of squares decomposition of multivariate polynomials and the algorithmic construction is achieved through the use of semidefinite programming. The reduction techniques provide numerical solution of large-scale instances; otherwise they will be computationally infeasible to solve. The introduced method can be used for hybrid systems with linear or nonlinear vector fields. Finally simulation results show the correctness and validity of the designed method. Recommended by Editorial Board member Young Soo Suh under the direction of Editor Jae Weon Choi. The authors wish to express their thanks to Dr. A. Papachristodoulou and Dr. M. Peet for their helpful comments and suggestions. Mohammad Ali Badamchizadeh was born in Tabriz, Iran, in December 1975. He received the B.S. degree in Electrical Engineering from University of Tabriz in 1998 and the M.Sc. degree in Control Engineering from University of Tabriz in 2001. He received the Ph.D. degree in Control Engineering from University of Tabriz in 2007. He is now an Assistant Professor in the Faculty of Electrical and Computer Engineering at University of Tabriz. His research interests include Hybrid dynamical systems, Stability of systems, Time delay systems, Robot path planning. Sohrab Khanmohammadi received the B.S. degree in Industrial Engineering from Sharif University, Iran in 1977 and the M.Sc. degree in Automatic from University Paul Sabatie, France in 1980 and the Ph.D. degree in Automatic from National University, ENSAE, France in 1983. He is now a Professor of Electrical Engineering at University of Tabriz. His research interests are Fuzzy control, Artificial Intelligence applications in control and simulation on industrial systems and human behavior. Gasem Alizadeh was born in Tabriz, Iran in 1967. He received the B.S. degree in Electrical Engineering from Sharif University, Iran in 1990 and the M.Sc. degree from Khajeh Nasir Toosi University, Iran in 1993 and the Ph.D. degree in Electrical Engineering from Tarbiat Modarres University, Iran in 1998. From 1998, he is a Member of University of Tabriz in Iran. His research interests are robust and optimal control, guidance, navigation and adaptive control. Ali Aghagolzadeh was born in Babol, Iran. He received the B.S. degree in Electrical Engineering in 1985 from University of Tabriz, Tabriz, Iran, and the M.Sc. degree in Electrical Engineering in 1988 from the Illinois Institute of Technology, Chicago, IL. He also attended the School of Electrical Engineering at Purdue University in August 1998 where he was also employed as a part-time research assistant and received the Ph.D. degree in 1991. He is currently an Associate Professor of Electrical Engineering at University of Tabriz, Tabriz, Iran. His research interests include digital signal and image processing, image coding and communication, computer vision, and image analysis.     

Facial expression recognition based on Haar-like feature detection

In this paper we propose a novel approach for facial feature detection in color image sequences using Haar-like classifiers. The feature extraction is initialized without manual input and has the capability to fulfill the real time requirement. For facial expression recognition, we use geometrical measurement and simple texture analysis in detecting facial regions based on the prior detected facial feature points. For expression classification we used a three layer feed forward artificial neural network. The efficiency of the suggested approach is demonstrated under real world conditions. The text was submitted by the authors in English. Axel Panning was born in Magdeburg, Germany, in 1980. He received his Masters Degree (Dipl.-Ing.) in Computer Science at the University of Magdeburg, Germany, in 2006. He is currently working on a PhD thesis focusing on image processing, tracking, and pattern recognition. Ayoub K. Al-Hamadi was born in Yemen in 1970. He received his Masters Degree (Dipl.-Ing.) in Electrical Engineering and Information Technology in 1997 and his PhD in Technical Computer Science at the Ottovon-Guericke-University of Magdeburg, Germany, in 2001. Since 2002 he has been Assistant Professor and Junior-Research-Group-Leader at the Institute for Electronics, Signal Processing, and Communications at the Otto-von-Guericke-University Magdeburg. His research work concentrates on the field of image processing, tracking analysis, pattern recognition, and artificial neural networks. Dr. Al-Hamadi is the author of more than 60 articles. Robert Niese was born in Halberstadt, Germany, in 1977. He received his Masters Degree (Dipl.-Ing.) with distinction in computer science at the Otto-von-Guericke-University Magdeburg, Germany, in 2004. He gathered broad experience in several international internship investigations on medical image and data analysis, including MRI, CT, and EEG. He is currently working at Magdeburg University on his PhD thesis, which focuses on 3D, image processing, tracking, and pattern recognition. Robert Niese is the author of more than 15 publications. Bernd Michaelis was born in Magdeburg, Germany, in 1947. He received a Masters Degree in Electronic Engineering from the Technische Hochschule Magdeburg in 1971 and his first PhD in 1974. Between 1974 and 1980 he worked at the Technische Hochschule Magdeburg and was granted a second doctoral degree in 1980. In 1993 he became Professor of Technical Computer Science at the Otto-von-Guericke University Magdeburg. His research work concentrates on the field of image processing, artificial neural networks, pattern recognition, processor architectures, and microcomputers. Professor Michaelis is the author of more than 200 papers.     

在结构与随机扰动下的大系统的稳定性

在本文中,我们给出了在结构与随机扰动下的动态大系统的稳定性分析,建立了这类大系统的依概率吸引性,依概率一致有界性,依概率大范围渐近稳定性,p吸引性,一致p有界性,和大范围渐近p稳定性的结论。这些结论的假设是由孤立子系统和与其联系的李亚普诺夫函数,受扰系统的结构和作用在子系统上的随机扰动表出的。     

Cultural differences in social networking site use: A comparative study of China and the United States

This research compared social networking site (SNS) use in a collectivistic culture, China, and an individualistic culture, the United States (US). Over 400 college student participants from a Southwestern University in Chongqing, China, and 490 college participants from a Midwestern University in the US completed a survey about their use of SNSs – time spent, importance and motives for use. They then rated themselves on a variety of personal characteristics, namely the Big Five Personality factors, Loneliness, Shyness and Life Satisfaction. Results revealed cultural differences in SNS use. US participants spent more time in SNS, considered them to be more important and had more friends in SNSs than did Chinese participants. Self-ratings of personal characteristics also differed in the two cultures as did the personal characteristics that predicted SNS use. In general, personal characteristics were less effective in predicting SNS use in China than in the US. Findings suggest that in collectivistic cultures the importance of the family, friends and one’s groups may be partly responsible for Chinese participants’ lesser use of SNSs, whereas in individualistic cultures the importance of self and having more but less close and enduring friendships may be partly responsible for US participants’ greater use of SNSs. Personal characteristics predicted SNS use in both cultures but were stronger predictors in an individualistic culture than in a collectivistic, consistent with the emphasis on self in the former and on family, friends and one’s groups in the latter. Future research is needed to identify whether cultural values always take precedence over personal characteristics and motives in determining behavior in the virtual world.     

关于烟气在线监测装置SO2周期性异常的分析与处理

本文针对目前电厂脱硫烟气连续排放监测系统（CEMS）中SO2数据周期性波动,通过对历史数据曲线分析排查,发现取样探头温控仪故障导致取样探头加热器无法加热,烟气中水分遇冷凝结在管壁,管壁中的水分平时吸收烟气中的SO2,导致测量值偏低,待水珠汇聚变大流入下面带加热的取样管中后,水中溶解SO2的集中释放,导致数据在短期急剧上升,蒸发释放完后回归到原来的水平,形成这样一个周期性吸收和集中释放的过程。可见烟气取样管道温度保护环节在烟气测量中的作用非常重要。     

Are My Neighbours Ageing Yet? Local Dimensions of Demographic Change in German Cities

Among the highly developed countries, demographic ageing is particularly advanced in Germany. Accentuated by migration, there is great regional variation in the progress of demographic change. Within urban areas, residential neighbourhoods differ considerably in their demographic composition and perspectives. Based on municipal data, this paper examines regional variability in the diversity and pace of neighbourhood-level ageing. Focusing on the Rhine-Ruhr conurbation in North Rhine-Westphalia, the analysis outlines at what pace ageing proceeds in a variety of neighbourhoods, which attract no constant influx of working-age migrants. After decades of suburbanisation, in the period from 1998 to 2008 regional migration concentrated on the central districts of large cities. More profoundly in the most prosperous cities growing in population than in other cities, childless working-age adults separate from other age groups and family types in selected central city quarters. The findings suggest that spatial differentials in ageing are likely to affect future location decisions and, thereby, regional and local prosperity.     

The application of IT in organisations: Some trends and issues

Abstract

This paper describes some trends and issues in the application of information technology in organisations. Technology trends are outlined in the areas of computing power, telecommunications, networking, software and standards. Some trends in the applications of IT are described with respect to developments in information systems and office automation. Some differences in the likely role of IT in the industrialised and developing countries are discussed. The second half of the paper deals with issues in the management of IT applications in organisations, and issues are identified as being political, organisational and social in nature in addition to technical. A social systems framework is proposed for the analysis of these issues. Some specific IT issues are then discussed involving alternative stakeholder perspectives, the analysis of decision making processes, the process of consultation and communication and the organisational impacts of IT applications.     

A layered approach to learning coordination knowledge in multiagent environments

Multiagent learning involves acquisition of cooperative behavior among intelligent agents in order to satisfy the joint goals. Reinforcement Learning (RL) is a promising unsupervised machine learning technique inspired from the earlier studies in animal learning. In this paper, we propose a new RL technique called the Two Level Reinforcement Learning with Communication (2LRL) method to provide cooperative action selection in a multiagent environment. In 2LRL, learning takes place in two hierarchical levels; in the first level agents learn to select their target and then they select the action directed to their target in the second level. The agents communicate their perception to their neighbors and use the communication information in their decision-making. We applied 2LRL method in a hunter-prey environment and observed a satisfactory cooperative behavior. Guray Erus received the B.S. degree in computer engineering in 1999, and the M.S. degree in cognitive sciences, in 2002, from Middle East Technical University (METU), Ankara, Turkey. He is currently a teaching and research assistant in Rene“ Descartes University, Paris, France, where he prepares a doctoral dissertation on object detection on satellite images, as a member of the intelligent perception systems group (SIP-CRIP5). His research interests include multi-agent systems and image understanding. Faruk Polat is a professor in the Department of Computer Engineering of Middle East Technical University, Ankara, Turkey. He received his B.Sc. in computer engineering from the Middle East Technical University, Ankara, in 1987 and his M.S. and Ph.D. degrees in computer engineering from Bilkent University, Ankara, in 1989 and 1993, respectively. He conducted research as a visiting NATO science scholar at Computer Science Department of University of Minnesota, Minneapolis in 1992–93. His research interests include artificial intelligence, multi-agent systems and object oriented data models.