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Wideband Beamforming for Multipath Signals Based on Frequency Invariant Transformation

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International Journal of Automation and computing 2012年第4期9卷 420-428页

作者： Wei Liu Communications Research Group,department of electronic & electrical {3.,University of Sheffield,Sheffield,S1 3.D,UK Communications Research Group Department of Electronic & Electrical Engineering University of Sheffield Sheffield UK

It is well known that the performance of conventional adaptive beamformers degrades severely due to the presence of coherent or correlated interferences(multipath propagation) and various techniques have been developed to improve the performance of the ***,most of the work in the past has been focused on the narrowband *** this paper,the wideband beamforming problem in the presence of multipath signals is addressed,with a novel approach proposed by employing a pre-processing stage based on the frequency invariant beamforming(FIB) *** this approach,the received wideband array signals are first processed by an FIB network,and then a traditional narrowband adaptive beamformer or an appropriate instantaneous blind source separation(BSS) algorithm can be applied to the network *** is shown that with the proposed structure,cancellation of the desired signal is reduced,leading to a significantly improved output signal to interference plus noise ratio(SINR).

关键词： Wideband beamforming multipath signals frequency invariant beamforming blind beamforming convolutive mixtures.

Improved performance of GaN-based light-emitting diodes by using short-period superlattice structures

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Progress in Natural Science:Materials International 2010年第1期20卷 70-75页

作者： Yi-jung LIU~1,Chien-chang HUANG~1,Tai-you CHEN~1,Chi-shiang HSU~1,Shiou-ying CHENG~2, Kun-wei LIN~3.Jian-kai LIOU~1,Wen-chau LIU~1 1.Institute of Microelectronics,department of electrical {3.,National Cheng-Kung University, Tainan 70101,Taiwan,China 2.department of electronic {3.,Nation Ilan University,I-Lan 26041,Taiwan,China 3.department and Graduate Institute of Computer Science and Information {3., Chaoyang University of Technology,Taichung 413.9,Taiwan,China Institute of Microelectronics Department of Electrical Engineering National Cheng-Kung University Tainan 70101 Taiwan China department of electronic engineering Nation Ilan University I-Lan 26041 Taiwan China department and Graduate Institute of Computer Science and Information engineering Chaoyang University of Technology Taichung 41349 Taiwan China

An InGaN/GaN multiple-quantum-well（MQW）light-emitting diode（LED）with a ten-period i（undoped）-InGaN/p（Mg doped）-GaN（2.5 nm/5.0 nm）superlattice（SL）structure,was *** SL structure that can be regarded as a confinement layer of holes to enhance the hole injection efficiency is inserted between MQW and p-GaN *** studied LED device exhibits better current spreading performance and an improved quality,compared with a conventional one without SL *** to the reduced contact resistance as well as more uniformity of carriers injection,the operation voltage at 20 mA is decreased from 3.3. to 3.14 V.A remarkably reduced reverse-biased leakage current(10-7-10-9A)and higher endurance of the reverse current pulse are *** measured output power and external quantum efficiency（EQE）of the studied LED are 13.6 mW and 24.8%,respectively. In addition,significant enhancement of 25.4%in output power as well as increment of 5%in EQE for the studied devices is observed, as the studied devices show superior current spreading ability and reduction in dislocations offered by the SL structure.

关键词： GaN superlattice(SL) current spreading hole confinement electrostatic discharge(ESD)

Morphology and electrical conductivity of PACS

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Journal of Environmental Sciences 2000年第3期12卷 319-324页

作者： GAO Bao\|yu\+1, LIU Zong\|gang\+2, YUE Qin\|yan\+3. ZHAO Hua\|zhang\+3.(1. department of Environmental engineering, Shandong University, Jinan 250100, China 2. Environmental Monitoring Station of Huaiyin, Jinan 250022, China 3. department of Environ 山东大学山东济南 2 50 1 0 0 山东济南市槐荫区环境监测山东济南 2 50 0 2 2

Polyaluminium chlorides with sulfate ion(PACS) were prepared by using AlCl 3.6H 2O, Al(SO 4) 3.18H 2O and Na 2CO 3.as raw materials. The effects of basicity ( r ), Al 3. /SO 4 2- molar ratio and aging time on the morphology of PACS were observed by transmission electrical microscope. The influence of aging time on charge neutralization and coagulation effect of PACS was studied. The effects of basicity ( r ), Al 3. /SO 4 2- molar ratio and aging time on the electrical conductivity of PACS solution were also investigated. The experimental results show that the degree of polymerization of polyaluminium chloride(PAC) increases when SO 4 2- ion is added. The higher the basicity( r ) and the longer the aging time, the larger the size of polymer PACS. The ability of PACS neutralizing the charge on Kaolinite decreases with the increase of aging time. The electrical conductivity of PACS solution(the concentration of Al 3. ion is 0.18 mol/L) with different aging time is the function of the basicity and Al 3. /SO 4 2- molar ratios and has its maximum at r =0.5 and Al 3. /SO 4 2- =12.

关键词： coagulant PACS morphology transmission electron microscope electrical conductivity coagulation

A new method for adaptive color image filtering

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Chinese Science Bulletin 2000年第13期45卷 1230-1235页

作者： JIANG Gangyi, YU Mei & YU Bokang1. department, of Information & electronic engineering, Hang/hou University of Commerce, Hangzhou 3.003., China 2. department, of electronic engineering, Hangzhou institute of electronics engineering, Hangzhou 3.003., China 3. State Key Laboratory on Machine Perception, Peking University, Beijing 100871, China Correspondence should be addressed to Yu Mei department of Information & electronic engineering Hangzhou University of Commerce Hangzhou China State Key Laboratory on Machine Perception Peking University Beijing China department of electronic engineering Hangzhou Institute of Electronics Engineering Hangzhou China

An adaptive color image filter (ACIF) is proposed in this note. Through analyzing noise corruption of color image, efficient locally adaptive filters are chosen for image enhancement. The proposed adaptive color image filter combines advantages of both nonlinear vector filters and linear filters, it attenuates noise and preserves edges and details very well. Experimental results show that the proposed filter performs better than vector median filter, directional-distance filter, directional-magnitude vector filter, adaptive nearest-neighbor filter, and α-trimmed mean filter.

关键词： color image noise analysis locally adaptive filters adaptive color image filter (ACIF).

Research on dual-stator winding multi-phase high-speed induction generator with rectifier load

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Science China(Technological Sciences) 2008年第6期51卷 683-692页

作者： WANG XiangHeng1 & WU XinZhen2 1 department of electrical engineering, Tsinghua University, Beijing 100084, China 2 department of electrical engineering, Qingdao University, Qingdao 266071, China department of electrical engineering Tsinghua University Beijing China department of electrical engineering Qingdao University Qingdao China

Based on analysis and calculation of the relation between current harmonics and MMF harmonics in the dual-stator winding multi-phase high-speed induction gen-erator with a rectifier load, a new idea, which divides the generator system into two sub-systems to be analyzed individually, is presented. For the sub-system of the 12-phase power winding with a rectifier load, the loop current method is used to establish network equation set in terms of the network graph theory. The numerical stability problem is solved by alternating use of fixed time-step and varied time-step, and the voltage and current with their fundamental components of the power winding are obtained. For the other sub-system of the induction generator with dual-stator winding and solid cage rotor, the electromagnetic field analysis method and the multi-variable optimization approach are combined to get the con-trol winding current and stator frequency. Calculated results well match experiment results, indicating that the new proposed method is of effectiveness and high ac-curacy.

关键词： dual-stator winding induction generator rectifier load MMF analysis loop current method finite element method optimization approach

FUZZY ALGORITHM FOR RADAR SIGNAL PROCESSING

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国防科技大学学报 1995年第3期17卷 59-64,80页

作者： Zhuang Zhaowen Guo Guirong(department of electronic engineering, NUDT, Changsha, 410073.

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关键词：雷达模糊算法信号处理

Self-Organizing Tunnel Peers

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计算机工程 2002年第S1期28卷 7-12页

作者： CHEN Maoke , LI Xing (department of electronic engineering, Tsinghua University, Beijing 100084,China ) department of electronic engineering Tsinghua University Beijing 100084China

Tunneling is an important approach in IPv6 transition techniques. The tunnel broker model provides a way to build virtual IPv6 networks without manual ***, neither it adapts performance variation on the IPv4 infrastructure, norit is a scalable solution for a wide-area IPv6 networking environment. In this paper, a self-organizing tunnel peer (SOTP) model is *** peers are clustered in the SOTP system so that optimization is scalable. Four primitive operations related to --cluster constructionarrest,release,division and deathendow the system with the nature of self-organization. Occurrence and behavior of the operations are decided by criteria on the IPv4 end-to-end performance; hence measurement is an indispensable component of the system. The metabolism of cluster relaxes the requirement to accuracy of measurement and optimization.

关键词： S elf-organizationTunnelingEnd-to-end measurementIPv6

Spatial continuity incorporated multi-attribute fuzzy clustering algorithm for blood vessels segmentation

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Science China(Information Sciences) 2010年第4期53卷 752-759页

作者： HAO JuTao1*, ZHAO JingJing2 & LI MingLu3.1School of Optical-electrical and Computer engineering, University of Shanghai for Science and Technology, Shanghai 200093. China 2department of electrical engineering, Shanghai University of Electric Power, Shanghai 200090, China 3.2} of Computer Science and engineering, Shanghai Jiaotong University, Shanghai 200240, China School of Optical-electrical and Computer engineering University of Shanghai for Science and Technology Shanghai China department of electrical engineering Shanghai University of Electric Power Shanghai China department of Computer Science and engineering Shanghai Jiaotong University Shanghai China

A three-dimensional representation of vasculature can be extremely important in image-guided neurosurgery, pre-surgical planning. In this paper, a spatial continuity incorporated multi-attribute fuzzy clustering algorithm (MAFCM S) is proposed to segment entire blood vessels from TOF MRA images. This clustering method takes both the intensity information and the geometrical information into account, while most of the cur- rent clustering methods only deal with the former. In this method, a new dissimilarity measure, which integrates the intensity and the geometry shape dissimilarity, is introduced. Because of the presence of the geometrical information, the new measure is able to differentiate the pixels with similar intensity values within different geometrical shape structures. Experimental results show that the new algorithm can get better segmentation.

关键词： fuzzy c-means clustering scale space analysis spatial continuity blood vessel segmentation multi-attribute fuzzy clustering

Comparison study of trapped water in human erythrocytes by EPC and DSC method and its application

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Science China(Technological Sciences) 2004年第3期47卷 343-351页

作者： ZHAO Gang1, HE Liqun1, GUO Xiaojie2, LIU Zhong3. LUO Dawei1,3.& GAO Dayong1,3.1. Cryobiomedical engineering Research Institute, department of Thermal Science and Energy engineering, University of Science and Technology of China, Hefei 23.027, China 2. Red Cross Blood Center of Hefei, Hefei 23.022, China 3. department of Mechanical engineering, University of Kentucky, Lexington, KY 40506-0108, USA Cryobiomedical engineering Research Institute Department of Thermal Science and Energy Engineering University of Science and Technology of China Hefei 230027 China Red Cross Blood Center of Hefel Hefei 230022 China department of Mechanical engineering University of Kentucky Lexington KY 40506-0108 United States

The novel differential scanning calorimetry method for determining trapped water volume of human red blood cell during freezing process has been reexamined. Results show that the final erythrocyte volume is 53. of its isotonic volume after freezing to -40℃. An electronic particle counter (MultisizerTM III, Beckman Coulter Inc., USA) was used to measure cell volume changes in response to hypertonic solution. Using this approach, when extracellular solution was 3.86 mOsm, the equilibrium cell volume was found to be 57% of its isotonic value. Both results indicate that 3.%—40% of intracellular water is trapped and cannot respond to osmotic difference between intra- and extracellular solution. These findings are consistent with the published data: at least 20%—3.% of the isotonic cell water volume is retained within RBCs during freezing. Some applications of the values of trapped water are addressed.

关键词： differential scanning calorimeter/DSC, electronic particle counter/EPC, cell volumetric change, red blood cell/RBC/erythrocyte