检索结果-内蒙古大学图书馆

Annual Conference of Industrial electronics Society

作者： Ching-Shan Leu F.C. Lee J.H. Liang Center for Power Electronics System The Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg VA USA Skynet Electronic Company Limited Taipei Taiwan

Employing the transformer leakage inductance, one cross-coupled capacitor, one clamped diode and two switches, an advanced Integrated Filter Converter (IFC) with two-switch forward configuration is proposed. By adding two extra diodes, it provides a comprehensive solution to perform core-reset, input filter, voltage-clamped and voltage-sharing functions. Consequently, non-pulsating input current, low voltage stress and high efficiency performance can be achieved. In this paper, the circuit operation is illustrated by PSpice simulation waveforms, and an experimental circuit of a 100 kHz, 10V/20A is described.

关键词： Filters Diodes Circuits Inductance Capacitors Switches Switching converters Transformer cores Low voltage Stress

来源：评论

学校读者我要写书评

暂无评论

PN code tracking for STBC transmit diversity RAKE receivers in closely spaced multipath environments

PN code tracking for STBC transmit diversity RAKE receivers ...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： B.S. Nugroho R.D. Balakrishnan H.M. Kwon D.H. Kang Department of Electrical and Computer Engineering Wichita State University Wichita KS USA IMT-2000 System R&D Team IT Center Samsung Electronics Company Limited Suwon Gyeonggi South Korea

Conventional early-late-gate (ELG) pseudo-noise (PN) code tracking shows poor performance in closely spaced multi-path environments where multiple path separation is less than 1.5 times PN chip interval for example. Fock et al. (Dec. 2001) proposed an efficient PN code tracking scheme for a RAKE receiver with a single transmit antenna and a single receive antenna by canceling the self-interference coming from the closely spaced adjacent multipaths. However, a general trend for 3G or future wireless communication system development is to employ multiple transmit and multiple receive antennas instead of a single transmit antenna. The space time block code (STBC) in S. Alamouti (Oct. 1998) is one of popular transmit antenna diversity schemes. In this paper we propose a PN code tracking algorithm for the STBC transmit diversity system under 3GPP specifications, extending the work by Fock et al. (Dec. 2001). Channel estimation for the transmit diversity system is provided with the aid of primary common pilot channel (P-CPICH) pattern. Simulations show that the proposed algorithm can eliminate the effects of the adjacent paths and can make an improvement in the root mean square (RMS) of the timing error compared to system without transmit diversity, e.g., 2 dB in chip-energy-to-noise-density ratio E/sub c//N/sub 0/ at RMS = 0.1.

关键词： Fading Multipath channels Transmitting antennas Receiving antennas Channel estimation Timing Delay estimation Interference cancellation Diversity methods Research and development

来源：评论

学校读者我要写书评

暂无评论

Field emission characteristics of nodular carbon nanotubes

Journal of Vacuum Science & Technology B: Microelectronics a...

引用

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena 2003年第4期21卷 1684-1687页

作者： Qiong Li Jingfang Xu Ke Yu Ziqiang Zhu Tao Feng Xi Wang Xianghuai Liu W. P. Kang J. L. Davidson Department of Electronics Science and Technology East China Normal University Shanghai 200062 China Ion Beam Laboratory Shanghai Institute of Micro-system and Information Technology Chinese Academy of Science Shanghai 200050 China Department of Electrical and Computer Engineering Vanderbilt University Nashville Tennessee 37235

A configuration of carbon nanotubes (CNTs) whose surfaces were fully covered with nanoscale nodes was developed in our laboratory. We named this material nodular CNTs or NCNTs. A hydrogen plasma process was used to turn common CNTs into NCNTs. Combined with this process, a technique has been developed to make planar NCNTs field emitters. Field emission experiments showed that planar NCNTs emitters had superior field emission characteristics. Specifically, the emission site density was increased by the order of 106/cm2. A suggestion was given to interpret the formation of NCNTs and a simple model was also proposed to explain the improvement of field emission properties. This technique was found to be an easy way to change the geometric character of CNTs in large quantities and will be useful for creating planar field emitters used in field emitter light sources or display devices.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A new adaptive algorithm for MSNR beamforming in WCDMA system

A new adaptive algorithm for MSNR beamforming in WCDMA syste...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： F. Alam Donghee Shim B.D. Woerner Department of Computer Science and Engineering North South University Banani Dhaka-1213 Bangladesh Standardization & System Research Group LG Electronics Inc. Anyang Kyoungki Korea Bradley Dept. of Elec. & Comp. Engineering Virginia Polytechnic Institute and State University Blacksburg VA USA

In a code division multiple access (CDMA) system, the optimum weight vector of an adaptive antenna array is the principal eigenvector (eigenvector corresponding to the maximum eigenvalue) of the covariance matrix of the received signal at the output of the despreader [S. Choi & D. Yun, Sept. 1997]. Consequently the weight vector can be computed by solving a simple eigenvalue problem (SE) [F. Alam et al., May 2002]. In this paper we develop a new adaptive algorithm based on the Lagrange multiplier technique to solve the SE. The computational complexity of the proposed algorithm is linear with the number of antenna elements. We investigate different aspects like the convergence and tracking property of the proposed algorithm. We employ a beamformer-RAKE [A. F. Naguib, Aug. 1996] receiver at the uplink of a wideband CDMA (WCDMA) [UMTS, 3G TS 25.213 V3.2.0 (2000-03)], [UMTS, 3G TS 25.211 V3.2.0 (2000-03)] system to test the performance of the adaptive algorithm. We compare the proposed algorithm with another Lagrange multiplier based algorithm [S. Choi & D. Shim, Sept. 2000] in terms of computational complexity, rate of convergence and bit error rate (BER) performance of the beamformer-RAKE receiver in multipath environment.

关键词： Adaptive algorithm Array signal processing Multiaccess communication Adaptive arrays Eigenvalues and eigenfunctions Lagrangian functions Computational complexity Convergence 3G mobile communication Bit error rate

来源：评论

学校读者我要写书评

暂无评论

A combined test structure with ring oscillator and inverter chain for evaluating optimum high-speed/low-power operation

A combined test structure with ring oscillator and inverter ...

引用

IEEE International Conference on Microelectronic Test Structures

作者： T. Matsuda H. Iwata T. Ohzone K. Yamashita N. Koike K. Tatsuuma Department of Electronics and Informatics Toyama Prefectural University Imizu Toyama Japan Faculty of Computer Science and System Engineering Okayama Prefectural University Soja Okayama Japan WLSI Process Technology Development Center Semiconductor Company Matsushita Elecrric Indusrrial Company Limited Minami Kyoto Japan

A test structure combined with a ring oscillator, an inverter chain and an embedded monitor inverter, which allows accurate internal node access, is proposed. V/sub dd/ and well-bias dependence of gate delay and supply current measured by both ring oscillator and inverter chain scheme. V/sub T/ control method by well biasing, particularly to forward direction, is effective for high speed operation under low supply voltage. The new test structure can be utilized to evaluate optimum conditions for high-speed/low-power operations as well as high-reliability operations.

关键词： Ring oscillators Inverters Circuit testing MOSFET circuits Threshold voltage Voltage control Circuit optimization Electronic equipment testing Delay CMOS process

来源：评论

学校读者我要写书评

暂无评论

Human systems integration and advanced technology in engineering department workload and manpower reduction

引用

NAVAL ENGINEERS JOURNAL 2003年第1期115卷 57-65页

作者： Lively, KA Seman, AJ Kirkpatrick, M KENNETH A. LIVELY graduated from the University of Colorado with a BS in applied mathematics and an MS in mathematics in 1976 and from the Massachusetts Institute of Technology with an MS in electrical engineering and the degree ocean engineer in naval architecture and marine engineering in 1984. He retired from the U.S. Navy in 1989 after 23 years of service. Assignments included electrical officer on the USS Constellation (CV 64) project engineer for the DDG 51 machinery control system (NAVSEA) and DDG 51 Technical Director (NAVSEA). He was vice president of the PDI Division of Bird-Johnson Company from July 1989 to November 1998 where he managed various gas turbine and machinery controls related development projects. He joined Anteon Corporation's Systems Engineering Group as senior controls engineer in December 1998 where he provided technical support to the integrated power systems program (NAVSEA PMS 510) and managed the Office of Naval Research Afloat Laboratory. DR. MARK KIRKPATRICK is currently an independent consultant in human factors and work-load/manning analysis and modeling. He holds a Ph.D. degree in experimental psychology from The Ohio State University and has 34 years of experience in applied human factors. From 1982 through 2000 Dr. Kirkpatrick served as the senior vice president of Carlow International. Prior to joining Carlow in 1982 Dr. Kirkpatrick served as a member of the technical staff at North American Rockwell's Missiles Division and as a project director and vice president for Essex Corporation. His areas of expertise include workload simulation task analysis operator-in-the-loop simulation human performance experimentation statistical analysis and human factors T&E. He has directed and/or participated in human factors projects for the U.S. Navy U.S. Army NASA Department of Transportation the U.S. Nuclear Regulatory Commission and private industry. ANTHONY J. SEMAN III is the technical manager for the reduced ship's crew by virtual presence (RSVP) advanced technology d

Aboard current ships, such as the DDG 51, engineering control and damage control activities are manpower intensive. It is anticipated that, for future combatants, the workload demand arising from operation of systems under conditions of normal steaming and during casualty response will need to be markedly reduced via automated monitoring, autonomous control, and other technology initiatives. Current DDG 51 class ships can be considered as a manpower baseline and under Condition III typical engineering control involves seven to eight watchstanders at manned stations in the Central Control Station, the engine rooms and other machinery spaces. In contrast to this manning level, initiatives such as DD 21 and the integrated engineering plant (IEP) envision a partnership between the operator and the automation system, with more and more of the operator's functions being shifted to the automation system as manning levels decrease. This paper describes some human systems integration studies of workload demand reduction and, consequently, manning reduction that can be achieved due to application of several advanced technology concepts. Advanced system concept studies in relation to workload demand are described and reviewed including. Piecemeal applications of diverse automation and remote control technology concepts to selected high driver tasks in current DDG 51 activities. Development of the reduced ship's crew by virtual presence system that will provide automated monitoring and display to operators of machinery health, compartment conditions, and personnel health. The IEP envisions the machinery control system as a provider of resources that are used by various consumers around the ship. Resource needs and consumer priorities are at all times dependent upon the ship's current mission and the availability of equipment pawnbrokers.

关键词： Naval warfare

来源：评论

学校读者我要写书评

暂无评论

Affecting the accuracy of an active vision head 2nd

引用

2nd Hellenic Conference on Artificial Intelligence, SETN 2002

作者： Gasteratos, Antonios Sandini, Giulio Laboratory of Electronics Section of Electronics and Information Systems Technology Department of Electrical and Computer Engineering Democritus University of Thrace XanthiGR-671 00 Greece Laboratory for Integrated Advanced Robotics Department of Communication Computer and System Sciences University of Genoa Viale Causa 13 GenoaI-16145 Italy

ISBN: (纸本)3540434720

In any measuring system the categorization of the error generation factors leads to simplification of complex error problems and to higher suppression of the error. In this paper we categorize, quantify and analyze the errors that affect a binocular active vision head. Simulations have been made and experimental results on a high resolution pan-tilt-vergence mechanism are also proposed. As a conclusion it can be said that the system performs optimal when it is initialized so that the two cameras are perfectly aligned and perpendicular to the baseline. Small variations in the vergence angle or small horizontal deviations of the principal point alters the measurement dramatically. On the other hand, variations in pan and tilt and vertical deviations of the principal point, affect the measurement insignificantly. © Springer-Verlag Berlin Heidelberg 2002.

关键词： Errors

来源：评论

学校读者我要写书评

暂无评论

Non-adiabatic losses in fused fiber couplers-experimental findings

Non-adiabatic losses in fused fiber couplers-experimental fi...

引用

2002 5th IEEE International Conference on Semiconductor electronics, ICSE 2002

作者： Shaarj, Ahmad Zaki Abdullah, Mohd. Khazani Shaarj, Sahbudin Photonics Technology Laboratory Department of Electrical Electronics and System Engineering Universit i Kebangsaan Malaysia 43600 UKM Bangi Selangor Malaysia Photonics Laboratoiy Department of Computer and Communication Systems Engineering Universiti Putra Malaysia 43400 UPM Serdang Selangor Malaysia

ISBN: (纸本)0780375785

Bi-conically tapered single-mode couplers are fabricated using a fiber fusion coupler workstation. Losses found during fabrication are analyzed for a range of elongation. It is found that longer elongations will lower the losses. Theoretically, the losses are due to the taper paths crossing delineating curves. These losses which occur during tapering process are not really adiabatic if part of the signal power is not guided at the end of tapering process. In other words, taper path will not be inside adiabatic region of cladding guidance. It will cross from core-guidance region into lossy region or non-adiabatic region of cladding guidance.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A primary-side-assisted zero-voltage and zero-current switching three-level DC-DC converter with phase-shift control

A primary-side-assisted zero-voltage and zero-current switch...

引用

Annual IEEE Conference on Applied Power electronics Conference and Exposition (APEC)

作者： S.J. Jeon F. Canales P.M. Barbosa F.C. Lee Center for Power Electronics System (CPES) Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg VA USA

ISBN: (纸本)0780374045

A new primary-side-assisted zero-voltage and zero-current switching (ZVZCS) three-level DC-DC converter with phase-shift control is proposed. Three-level converters show promise for use in high-voltage applications, and ZVZCS is a very effective means for reducing switching losses. The proposed DC-DC converter uses only one auxiliary transformer and two diodes to achieve ZCS for the inner leg. It has a simple and robust structure, and offers soft-switching capability even in short-circuited conditions. The proposed converter was verified by experiments using a 6 kW prototype designed for communication applications and operating at 100 kHz.

关键词： Zero current switching DC-DC power converters Switching converters Switches Zero voltage switching Circuits Inductors Capacitors Diodes Pulse transformers

来源：评论

学校读者我要写书评

暂无评论

Sensorless indirect field-oriented control of induction motors, based on high gain speed estimation

Sensorless indirect field-oriented control of induction moto...

引用

Annual Conference of Industrial electronics Society

作者： S. Peresada M. Montanari A. Tilli S. Kovbasa Department of Electrical Engineering Kiev Politechnical Institute National Technical University Kiev Ukraine Department of Electronics Computer and System Sciences (DEIS) University of Bologna Bologna Italy

A novel speed sensorless control algorithm for IM with analytically proven local asymptotic stability properties is presented. It provides asymptotic speed tracking and flux regulation under condition of constant load torque. Conditions of persistency of excitation are defined; they coincide with the well-known nonzero excitation frequency of IM. Intensive experimental study demonstrates performance suitable for wide spectrum of technological applications.

关键词： Sensorless control Induction motors Torque control Asymptotic stability Mechanical sensors Stators Sliding mode control Algorithm design and analysis Frequency Rotors

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：