检索结果-内蒙古大学图书馆

EMC'98 ROMA International Symposium on Electromagnetic Compatibility

作者： F. Rachidi M. Rubinstein P. Zweiacker M. Ianoz B. Braendli A. Kaelin University of Toronto Dept. of Electrical and Computer Engineering Canada. Montena EMC CH-1728 Rossens Switzerland. Swisscom R&D CH-3000 Bern Switzerland. Swiss Federal Institute of Technology Power Systems Laboratory CH-1015 Lausanne Switzerland. Swiss Defense Procurement Agency NEMP Labor AC Zentrum CH-3700 Spiez Switzerland.

ISBN: (纸本)9798331500016

The aim of this paper is to quantify the lightning-induced disturbances on short overhead lines. An experimental study was carried out in Camp Blanding in 1995 in which the current induced on a short structure by artificially-initiated lightning was measured. For the considered electrically-short structures, is that the induced signals can be predicted with reasonable accuracy using a simple quasistatic approach. Further experiences conducted in a high voltage laboratory allowed us to propose protective solutions.

关键词： Lightning Current measurement Magnetic fields Telephone sets Circuits Magnetic field measurement Wire Cables Voltage measurement Protection

来源：评论

学校读者我要写书评

暂无评论

A Region-Based Representation of Images in MARS

引用

Journal of VLSI Signal Processing systems for Signal, Image, and Video technology 1998年第1-2期20卷 137-150页

作者： Servetto, Sergio D. Rui, Yong Ramchandran, Kannan Huang, Thomas S. Beckman Inst. Adv. Sci. and Technol. Univ. Illinois at Urbana-Champaign Urbana IL 61801 United States Universidad Nacional de La Plata Argentina Univ. Illinois at Urbana-Champaign United States Comp. Res. Adv. Applications Group IBM Argentina Argentina Image Formation and Processing Group Beckman Institute UIUC United States Department of Computer Science UNLP Argentina Dept. of Elec. and Comp. Engineering UIUC United States Multimedia Commun. Res. Department Bell Laboratories Murray Hill NJ United States Info. Sciences Research Department AT and T Labs. Florham Park NJ United States Department of Computer Science UIUC United States Southeast University China Tsinghua University China University of Illinois Urbana-Champaign IL United States Image Formation and Processing Group Beckman Inst. Advance Sci. Technol. UIUC United States Vis. Technol. Grp. of Microsoft Res. Redmond WA United States City College of New York United States Columbia University United States AT and T Bell Labs. United States Ctr. for Telecommunications Research Columbia University United States Elec. and Comp. Eng. Department United States Beckman Institute Coordinated Science Laboratory IL United States IEEE Signal Processing Society United States IEEE IMDSP Technical Committee United States IEEE Transactions on Image Proc. United States National Taiwan University Taipei Taiwan Massachusetts Inst. of Technology Cambridge MA United States Department of Electrical Engineering MIT United States School of Electrical Engineering United States Lab. for Info. and Signal Processing Purdue University United States Dept. of Elec. and Comp. Engineering United States Coordinated Science Laboratory United States Image Formation and Processing Group Beckman Inst. Adv. Sci. and Technol. United States MIT Lincoln Laboratory IBM Thomas J. Watson Research Center Rheinishes Landes Museum Bonn Germany Swiss Institutes of Technology Zurich Switzerland Swiss Institutes of Technology Lausanne S

We study the problem of representing images within a multimedia Database Management System (DBMS), in order to support fast retrieval operations without compromising storage efficiency. To achieve this goal, we propose new image coding techniques which combine a wavelet representation, embedded coding of the wavelet coefficients, and segmentation of image-domain regions in the wavelet domain. A bitstream is generated in which each image region is encoded independently of other regions, without having to explicitly store information describing the regions. Simulation results show that our proposed algorithms achieve coding performance which compares favorably, both perceptually and objectively, to that achieved using state-of-the-art image/video coding techniques while additionally providing region-based support.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Ion implanted GaAs/InGaAs lateral injection ridge QW laser for OEICs: Study of operation mechanisms 24

Ion implanted GaAs/InGaAs lateral injection ridge QW laser f...

引用

24th IEEE International Symposium on Compound Semiconductors, ISCS 1997

作者： Tager, A.A. Gaska, R. Avrutsky, L.A. Fay, M. Chik, H. Springthorpe, A. Husain, Z. Xu, J.M. Shur, M. University of Toronto Dept. of Electrical and Computer Engineering TorontoONM5S1A4 Canada University of Virginia Dept. of Electrical Engineering CharlottesvilleVA United States APA Optics Inc. MN United States Nortel Technology NepeanON Canada Rensselaer Polytechnic Institute Dept. Electrical Computer and Systems Engineering TroyNY United States

ISBN: (纸本)0780338839

We have fabricated and characterized lateral current injection (LCI) ridge-waveguide lasers with implanted contacts. Comprehensive optical and electrical measurements have been performed over a wide temperature range (10 K to 300 K) on two sets of lasers with differing ridge widths and active region structures. Several new phenomena unique to the LCI mechanism have been observed and explained, including a positive differential resistance kink at threshold, and an inverse temperature-dependence of quantum efficiency and threshold current at cryogenic values. Electron/hole mobility disparity, local carrier nonpinning above threshold due to photon-assisted carrier diffusion, and intrinsically higher current densities have been experimentally identified as the major factors governing LCI laser characteristics. The results have important implications for optimum LCI laser design and ultimate performance. © 1998 IEEE.

关键词： Injection lasers

来源：评论

学校读者我要写书评

暂无评论

Optimal edge detection under difficult imaging conditions 3rd

Optimal edge detection under difficult imaging conditions

引用

3rd Asian Conference on computer Vision, ACCV 1998

作者： Bhuiyan, Md. Shoaib Iwahori, Yuji Iwata, Akira Educational Center for Information Processing Nagoya Institute of Technology Nagoya466-8555 Japan Dept. Electrical and Computer Engineering Nagoya Institute of Technology Nagoya466-8555 Japan

ISBN: (纸本)3540639314

This paper incrementally extends the energy minimization techniques for image analysis developed by [Koch et al. 1986]. Our application is edge extraction and we use the duM intensity and line processes introduced by [Geman and Geman~ 1984]. The approach seeks to minimize a global energy functional that explicitly incorporates image properties to be minimized into weighted terms of the energy functionM. Our specific contribution is modifying the weighting of terms in the energy functional that were previously independent of spatiM gray level change to explicitly include spatial change in the weighting. Wre argue that the weighting used in previous implementations resulted in a reduced contribution from the edge components due to a dominance of the spatial intensity difference term as that spatial difference increases in size. Our specific modification compensates for this effect by scaling the edge process weighting factors by the spatial difference value (to the second order), thus, maintaining the same relative effect as the spatial difference increases. We found that the proposed algorithm works significantly better as compared to Koch et al. because of this modification. © 1997, Springer Verlag. All rights reserved.

关键词： Edge detection

来源：评论

学校读者我要写书评

暂无评论

Incorporating contextual information in white blood cell identification 97

Incorporating contextual information in white blood cell ide...

引用

Proceedings of the 11th International Conference on Neural Information Processing systems

作者： Xubo Song Yaser Abu-Mostafa Joseph Sill Department of Electrical Engineering California Institute of Technology Pasadena CA Dept. of Electrical Engineering and Dept. of Computer Science California Institute of Technology Pasadena CA Computation and Neural Systems Program California Institute of Technology Pasadena CA

In this paper we propose a technique to incorporate contextual information into object classification. In the real world there are cases where the identity of an object is ambiguous due to the noise in the measurements based on which the classification should be made. It is helpful to reduce the ambiguity by utilizing extra information referred to as context, which in our case is the identities of the accompanying objects. This technique is applied to white blood cell classification. Comparisons are made against "no context" approach, which demonstrates the superior classification performance achieved by using context. In our particular application, it significantly reduces false alarm rate and thus greatly reduces the cost due to expensive clinical tests.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A PLZT-based dynamic diffractive optical element for high speed, random-access beam steering

A PLZT-based dynamic diffractive optical element for high sp...

引用

Conference on Optical Scanning systems - Design and Applications

作者： Thomas, JA Lasher, M Fainman, Y Soltan, P Dept. of Electrical and Computer Engineering MC 0407 University of California at San Diego San Diego CA 92093-5003 9500 Gilman Drive United States Naval Command Control and Ocean Surveillance Center Research Development Test and Evaluation Division Advanced Technology Branch San Diego CA 92152-5732 53490 Dow Street United States

ISBN: (纸本)0819425532

A novel type of electro-optic diffractive element is presented which can satisfy the requirements for a high space-time bandwidth deflector while providing for two-dimensional random access beam steering control. The basic device consists of a multichannel array of phase modulators fabricated using Lanthanum-modified Lead Zirconate Titanate (PLZT) operating as a programmable diffractive optical element. Two-dimensional deflection control can be readily obtained by crossing two one-dimensional arrays. This device is useful for wavelengths in the Visible to Mid-IR range and is based on PLZT ceramic materials which can be readily mass-produced. It possesses the versatility and multifunctionality of liquid crystal based optical phased array systems while allowing for very fast switching speeds with good thermal stability. We present a brief comparison of this novel deflector with other scanning technologies and outline the benefits and trade-offs of the PLZT-based device. Experiments on 16- and 32-channel arrays with fullwave voltages less than 400 volts demonstrate continuous lateral beam steering control of a HeNe laser beam. We also demonstrate full deflection control with a minimum number of control lines using a modified deflector arrangement. And we present measurements showing sub-microsecond switching speeds from such PLZT-based phase modulators. Mature versions of this type of scanner will find use in a wide variety of applications including 2-D and 3-D laser displays, laser communications, and LIDAR systems.

关键词： Light modulators

来源：评论

学校读者我要写书评

暂无评论

Fault-Tolerant Model Based Predictive Control with Application to Boiler systems

引用

IFAC Proceedings Volumes 1997年第18期30卷 1231-1236页

作者： Won-Kee Son Oh-Kyu Kwon M.E. Lee Laboratory for Control and Instrumentation Systems School of Electrical and Computer Engineering Inha University Inchon 402-751 Koreo Tel: +82-32-860-7395 Fax: +82-32-863-5822 Dept. of Information and Communication Engineering Koreo Institute of Technology and Education Chonan Chungnam 333-860 Korea

This paper deals with the fault-tolerant control problem under nonlinear boiler systems with noise and disturbance. MCMBPC (Multivariable Constrained Model-Based Predictive Controller) proposed by Wilkinson et al . is used and modified in this paper in order to be applied to nonlinear boiler systems. Fault-tolerant control scheme combining MCMBPC with a fault detection method based on the unknown input observer is proposed. The fault-tolerant controller proposed is shown, via simulation, to have acceptable tracking performance even under some faults of input valves in the boiler system.

关键词： Fault-tolerant fault detection model-based predictive control boiler systems

来源：评论

学校读者我要写书评

暂无评论

Covering radius and discrete Chebyshev polynomials

Covering radius and discrete Chebyshev polynomials

引用

IEEE International Symposium on Information Theory

作者： I. Honkala T. Laihonen S. Litsyn Dept. of Math. Turku Univ. Finland Turku Center for Computer Science Turku Finland Department of Mathematics University of Turku Turku Finland Department of Electrical Engineering-Systems Tel-Aviv University Israel

We derive a new upper bound on the covering radius of a code as a function of its dual distance. This bound improves on the bound proved previously (Honkala et al., 1995) and in a certain interval it is also better th... 详细信息

关键词： Chebyshev approximation Polynomials Upper bound Mathematics computer science Data compression Error correction codes Decoding Linear code Hydrogen

来源：评论

学校读者我要写书评

暂无评论

Optimized aluminum back surface field techniques for silicon solar cells

Optimized aluminum back surface field techniques for silicon...

引用

Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997

作者： S. Narasinha A. Rohatgi Dept. of Electr. & Comput. Eng. Georgia Inst. of Technol. Atlanta GA USA Department of Electrical and Computer Engineering Georgia Institute of Technology University Center of Excellence for Photovoltaics Research and Education Atlanta GA USA

Screen-printed Al and rapid thermal alloying have been combined in order to achieve an Al back surface field (Al-BSF) which lowers the effective back surface recombination velocity to 200 cm/s on 2.3 /spl Omega/cm Si. This Al-BSF process has been integrated into a high-efficiency, laboratory fabrication sequence as well as a high-throughput, industrial-type process in order to achieve solar cell efficiencies in excess of 19.0% and 17.0%, respectively, on 2.3 /spl Omega/cm FZ Si. For both process sequences, the efficiency values are 1-2 absolute percentage points higher than cells made with unoptimized Al-BSFs. The critical process requirements for optimal Al-BSF formation are: (1) the use of a fast ramp rate to reach the alloying temperature; and (2) thick film Al deposition prior to alloying.

关键词： Aluminum Silicon Alloying Rapid thermal processing Laboratories Fabrication Textile industry Photovoltaic cells Temperature Thick films

来源：评论

学校读者我要写书评

暂无评论

Effects of Cr2O3 or Y2O3 doping in barium ferrite thin-film medium for high-density recording

引用

JOURNAL OF APPLIED PHYSICS 1996年第8期79卷 4878-4880页

作者： Chen, YJ Kryder, MH Data Storage Systems Center Dept. of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh Pennsylvania 15213

The effects of Cr2O3 or Y2O3 doping on the surface morphology and magnetic properties in barium ferrite thin films have been studied. Thin films were deposited by co-sputtering a barium ferrite target with a Cr2O3 or Y2O3 target. The deposited amorphous films were homogenized at a temperature of 600 degrees C for over 10 h followed by annealing at 800 degrees C in a tube furnace. It was observed that, whereas stoichiometric barium ferrite shows 5000 Angstrom x500 Angstrom acicular grainlike features, films doped with Cr2O3 or Y2O3 had equiaxed topographic features with an average size of 500 Angstrom. Magnetic studies showed that the coercivity of the doped films was over 3500 Oe and was larger than that of stoichiometric films. A weak magnetostatic interaction was found in all the films. Studies of the magnetic after effect indicated excellent thermal stability in all the films. (C) 1996 American Institute of Physics.

关键词：

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：