一种分布式混合预约多址(DHRMA)协议的研究

本文在D-PRMA协议的基础上对其进行改进,提出一种分布式混合预约多址(DHRMA)协议。DHRMA协议采用混合式预约机制,并配合使用时隙表,来减小业务竞争所造成的碰撞的概率,解决隐藏终端和暴露终端问题,从而改善系统的性能并提高系统的吞吐量;同时赋予实时业务较高的优先级以满足其服务质量(QoS)的要求。另外,本文还采用了一种互同步技术,用以解决网络中节点之间的同步问题。     

谐和与随机噪声作用下二阶参激系统的Lyapunov指数

研究了二阶线性系统在谐和与随机噪声联合作用下的主共振响应和稳定性问题。用多尺度法分离了系统的快变项，讨论了系统的阻尼项、随机项等对系统响应的影响。用路径积分法求出了系统的稳态概率密度，从而求出了系统的最大Lyapunov指数，由最大Lyapunov指数可得系统几乎必然稳定的充分必要条件。数值模拟表明文中提出的方法是有效的。     

一种基于概率密度的多基阵声测被动定位算法

研究了基于概率密度分析的多基阵声测被动定位方法，并对定位算法和误差进行了理论分析和数值仿真。该方法将单基阵估计的目标方位看成是满足一定概率分布的一种可能的目标位置测量子集，根据每个单基阵得到的目标位置概率，计算目标位置在整个空间的概率密度分布，将概率密度最大点作为目标位置。研究结果表明，该声测被动定位方法的定位精度明显优于几何交叉定位法，具有重要的实用价值，它不仅可直接用于空中运动目标的探测和定位，而且也适用于地面运动目标的探测与定位。     

缝洞型碳酸盐岩油藏开发早期合理采油速度模型

对于缝洞型碳酸盐岩油藏，衰竭式开发是最合理的开采方式。对于衰竭式开采，在制定开发方案时，确定合理采油速度尤为重要。研究中根据其他相同类型油田的成功开采实例，选取尽可能多的影响因素，采用多元逐步回归分析方法。得到了一个缝洞型碳酸盐岩油藏开发早期合理采油速度模型。此模型包含了流体性质和地层参数，与关于固有地质情况对采油速度影响的物理概念并不矛盾，并且适应面广，可对衰竭式开发早期缝洞型碳酸盐岩油藏的合理采油速度做出初步结论。用数值模拟方法证明，这个模型可用于现场实际。     

基于CDMA技术的多水印算法

将码分多址（CDMA）思想引入水印系统以实现多水印方案。在水印嵌入过程中，每一用户以自己的密钥作为种子生成一个伪随机分布的地址码，并用该地址码将自己的欲嵌入信息调制为载波信号，然后以相加的方式把载波信号叠加入载体。在提取时，该用户使用相同的地址码，通过计算地址码和载体之间的相关系数，从载体中提取自己的嵌入信息。实验证明该算法可以实现多个用户独立嵌入和检测自己的水印信息，完全能满足多水印的要求。     

气象多数据源数据融合模型研究

在总结现有数据融合技术的基础上，对目前的通用多传感器数据融合技术进行了分析。基于气象网络研究领域的多数据源融合问题，提出了气象网络中多数据源的数据融合模型及其采用的主要技术思想，为气象网络中数据信息的多样化和网络结构的异构化带来的复杂的数据融合提供了参考。     

A high‐luminous‐efficacy PDP having multi‐anodes for reduction of ionic effect (MARI)

Abstract— We propose a PDP having a new structure and driving scheme. An auxiliary electrode was inserted between X and Y electrodes. Driving and discharge stability was determined using a test panel. A 42‐in. SD (852 × 480) panel and a 42‐in. HD (1366 × 768) panel were also made having this new structure, and we verified the increase in luminous efficacy and the reduction of ionic losses. We achieved a luminous efficacy of 2.35 lm/W in an SD panel and 1.97 lm/W in a HD panel. Finally, we investigated the characteristics and merits of the new structure.     

Real-time multiple people tracking using competitive condensation

The CONDENSATION (Conditional Density Propagation) algorithm has a robust tracking performance and suitability for real-time implementation. However, the CONDENSATION tracker has some difficulties with real-time implementation for multiple people tracking since it requires very complicated shape modelling and a large number of samples for precise tracking performance. Further, it shows a poor tracking performance in the case of close or partially occluded people. To overcome these difficulties, we present three improvements: First, we construct effective templates of people's shapes using the SOM (Self-Organizing Map). Second, we take the discrete HMM (Hidden Markov Modelling) for an accurate dynamical model of the people's shape transition. Third, we use the competition rule to separate close or partially occluded people effectively. Simulation results shows that the proposed CONDENSATION algorithm can achieve robust and real-time tracking in the image sequences of a crowd of people.     

多属性决策问题的交互线性分式规划算法

基于决策者的线性效用函数提出了一种求解多属性决策问题的交互线性分式规划算法.     

MIMO Channel Characterization for Short Range Fixed Wireless Propagation Environments

This paper reports results from wideband MIMO measurements performed in short range fixed wireless environments at 5.2 GHz. The objective is to provide MIMO channel characterization results for the measured environments and contribute to the limited available similar studies. Two kinds of propagation scenarios are investigated, rooftop to rooftop and street to rooftop, at three different sites always under LOS propagation conditions. The analysis of measurement data is performed in the context of non physical modeling, providing insight into the statistics of the measured channels. In particular, the slow time varying nature of the channel is studied and the narrow Doppler spectrum shape is approximated. Furthermore, frequency correlation results are obtained and the typical delay dispersion measures are extracted. Then, the antenna correlation is studied and the error of the Kronecker product approximation is evaluated. Finally, capacity results are provided and the channel measurements are characterized in terms of spatial multiplexing quality and multipath richness through condition number analysis. Nikolaos D. Skentos received his Diploma in Electrical and Computer Engineering from the National Technical University of Athens (NTUA), Greece in October 2000. Since January 2001 he has been a research associate at the Mobile Radio Communications Laboratory at the NTUA, and he is currently working towards the Ph.D. degree. His research interests include channel measurements, MIMO channel characterization, MIMO algorithms and space time processing. He has been active in the IST STINGRAY project, the COST 273 Action and the ACE Network of Excellence. He is also a member of the National Technical Chamber of Greece since 2001. Athanasios G. Kanatas received the Diploma in Electrical Engineering from the National Technical University of Athens, Greece, in 1991, the M.Sc. degree in Satellite Communication Engineering from the University of Surrey, Surrey, UK in 1992, and the Ph.D. degree in Mobile Satellite Communications from the National Technical University of Athens, Greece in February 1997. From 1993 to 1994 he was with National Documentation Center of National Research Institute. In 1995 he joined SPACETEC Ltd. where he was Technical Project Manager for VISA/EMEA VSAT Project in Greece. In 1996 he joined the Mobile Radio Communications Laboratory as a research associate. From 1999 to 2002 he was with the Institute of Communication & Computer Systems. In 2000 he became a member of the Board of Directors of OTESAT S.A. He is an Assistant Professor in the Department of Technology Education and Digital Systems at University of Piraeus. His current research interests include channel characterization and estimation, simulation and modeling for mobile, mobile satellite, and future wireless communication systems. He has been a Senior Member of IEEE since 2002, and is also a member of the Technical Chamber of Greece. In 1999 he was elected Chairman of the Communications Society of the Greek IEEE Section. Panagiotis I. Dallas was born 1967 in Thessaloniki, Greece. He obtained his diploma and Ph.D. degree from the Electrical and Computer Engineering Department of Aristotle University of Thessaloniki, Greece, in 1990 and 1997, respectively. Since 1998 he joined with INTRACOM where he currently is Section Manager of Advanced Communications Technologies branch of Emerging Technologies & Markets department, leading the next generation of broadband wireless access systems for internal and EU projects. He runs the relevant standardization activities (IEEE 802.16 and ETSI/BRAN HIPERMAN) in INTRACOM and he represents the company in WiMAX forum. Finally, he has over 30 publications in international journals and conferences. Philip Constantinou received the Diploma in Physics from the National University of Athens in 1972, the Master of Applied Science in Electrical Engineering from the University of Ottawa, Ontario, Canada in 1976, and the Ph.D. degree in Electrical Engineering in 1983 from Carleton University, Ottawa, Ontario, Canada. From 1976 to 1979 he was with Telesat Canada as a Communications System Engineer. In 1980 he joined the Ministry of Communications in Ottawa, Canada where he was engaged in the area of Mobile Communication. From 1984 to 1989 he was with the National Research Center Demokritos in Athens, Greece where he was involved in several research projects in the area of Mobile Communications. In 1989 he joined the National Technical University of Athens where he is currently a Professor and Director of the Mobile Radio Communications Laboratory. His current research interests include Personal Communications, Mobile Satellite Communications, and Interference Problems on Digital Communications Systems.