检索结果-内蒙古大学图书馆

Two-stage adaptive PMD compensation in 40-Gb/s OTDM optical communication system

Chinese Optics Letters 2004年第6期2卷 316-319页

作者：张晓光席丽霞于丽周光涛张建忠张娜吴斌苑铁成陈林张洪明陈硕姚敏玉杨伯君 Department of Physics School of Science. Beijing University of Pouts and Telecommunications. Beijing 100876 Department of Electronic Engineering. Tsinghua University Beijing 100084 Department of Physics School of Science. Beijing University of Posts and Tclecommunications Beijing 100876n experiment of two-stage adaptive compensation for polarization mode dispersion (PMD) iu a 40-Gb/s optical time-division multiplexed communication system is reported. The PMD monitoring technique based on degree of polarization was adopted. The particle swarm optimization (PSO) algorithm was introduced in adaptive PMD compensation. The comparison was made to estimate the effectiveness between PSO algorithms with global neighborhood structure (GPSO) and with local neighborhood structure (LPSO). The LPSO algorithm is shown to be more effective to search global optimum for PMD compensation than GPSO algorithm. The two-stage PMD compensator is shown to be effective for both first- and second-order PMD and he compensator is shown to be bit rate independent. The optimum searching time is within one huudred milliseconds.

An experiment of two-stage adaptive compensation for polarization mode dispersion (PMD) iu a 40-Gb/s optical time-division multiplexed communication system is reported. The PMD monitoring technique based on degree of polarization was adopted. The particle swarm optimization (PSO) algorithm was introduced in adaptive PMD compensation. The comparison was made to estimate the effectiveness between PSO algorithms with global neighborhood structure (GPSO) and with local neighborhood structure (LPSO). The LPSO algorithm is shown to be more effective to search global optimum for PMD compensation than GPSO algorithm. The two-stage PMD compensator is shown to be effective for both first- and second-order PMD, and he compensator is shown to be bit rate independent. The optimum searching time is within one huudred milliseconds.

关键词： PMD Two-stage adaptive PMD compensation in 40-Gb/s OTDM optical communication system OTDM DOP

来源：评论

学校读者我要写书评

暂无评论

An ROI image coding based on switching wavelet transform

An ROI image coding based on switching wavelet transform

引用

IEEE International Symposium on Circuits and systems (ISCAS)

作者： S. Fukuma S. Ikuta M. Ito S. Nishimura M. Nawate Department of Electronic and Control System Engineering Shimane University Matsue Shimane JAPAN

We propose a region-of-interest (ROI) image coding based on the switching wavelet transform. In order to relax the restriction for the allocation of information quantity between ROI and region-of-non-interest (non-ROI), we employ a wavelet transform with shorter length basis for ROI, and a longer length wavelet with better compression performance for non-ROI. Moreover, we present a method of allocation of information quantity for the switching wavelet that can control the ratio of the restored image quality for ROI to that for non-ROI under a given total information quantity. Our method can avoid information loss for non-ROI at lower bitrate in JPEG-2000, therefore subjective image quality for the whole of the restored image is improved, maintaining the quality of ROI to be higher than that of non-ROI.

关键词： Image coding Wavelet transforms Image restoration Image quality Bit rate Wavelet coefficients Shape Indium tin oxide control systems systems engineering and theory

来源：评论

学校读者我要写书评

暂无评论

Improved algorithms for reducing estimated error produced by sample quantization and additional noise

Improved algorithms for reducing estimated error produced by...

引用

SICE Annual Conference

作者： H. Kubota K. Watanabe K. Kubo Postgraduate course of Electronic System Engineering Oyama National College of Technology Japan Department of Electronic Control Engineering Oyama National College of Technology Japan

Prony's method and binary method are evaluated for estimating sine-wave frequency, and are investigated from standpoints of error behavior in the frequency estimate. Since these methods are based on samples of sine-wave, the estimation is influenced by quantization. New technique is proposed to reduce the estimation error influenced both by the quantization and by additional noise in samples. By implementing this technique, higher accuracy in frequency estimation is achieved.

关键词： Quantization Noise reduction Frequency estimation Sampling methods Educational institutions Signal to noise ratio systems engineering and theory Testing FAA

来源：评论

学校读者我要写书评

暂无评论

Single switch DC-DC converter operating in CC and DC modes

Single switch DC-DC converter operating in CC and DC modes

引用

SICE Annual Conference

作者： K. Tripipatpornchai Y. Rungruengphalanggul A. Chaisawadi Department of Electrical and Electronic Engineering Faculty of Engineering Rangsit University Pathum Thani Thailand Department of Control System and Instrumentation Engineering Faculty of Engineering King Mongkut''s University of Technology Thonburi Bangkok Thailand

ISBN: (纸本)0780383524

This paper proposes a direct current buck converter which provides two independent regulated direct current output voltages using only single control switch. The first converter operation is based upon the use of continuous conduction mode (CCM) to regulate output voltage by controlling the duty cycle of the switch, while the second converter operation is based upon the use of discontinuous conduction mode (DCM) to regulate output voltage by controlling the duty cycle and changing the switching frequency. The system's operation is verified by results from computer simulation and experimentation from the prototype in this experiment, the switching frequency range is from 4 kHz to 90 kHz and the duty cycle range is from 20% to 42%. The overall efficiency of this converter is approximately 83% at full load.

关键词： Switches DC-DC power converters Switching converters Buck converters Inductors Voltage control Equations Switching frequency Circuits control systems

来源：评论

学校读者我要写书评

暂无评论

Obstacle classification by a line-crawling robot: A rough neurocomputing approach 3rd

Obstacle classification by a line-crawling robot: A rough ne...

引用

3rd International Conference on Rough Sets and Current Trends in Computing, RSCTC 2002

作者： Peters, James F. Ahn, T.C. Borkowski, Maciej Department of Electrical and Computer Engineering University of Manitoba WinnipegMBR3T5V6 Canada Intelligent Information Control ann System Lab School of Electrical and Electronic Engineering Won-Kwang University 344-2 Shinyong-Dong Iksan Chon-Buk570-749 Korea Republic of

ISBN: (纸本)9783540442745

This article considers a rough neurocomputing approach to the design of the classify layer of a Brooks architecture for a robot control system. In the case of the line-crawling robot (LCR) described in this article, rough neurocomputing is used to classify sometimes noisy signals from sensors. The LCR is a robot designed to crawl along high-voltage transmission lines where noisy sensor signals are common because of the electromagnetic field surrounding conductors. In rough neurocomputing, training a network of neurons is defined by algorithms for adjusting parameters in the approximation space of each neuron. Learning in a rough neural network is defined relative to local parameter adjustments. Input to a sensor signal classifier is in the form of clusters of similar sensor signal values. This article gives a very brief description of a LCR that has been developed over the past three years as part of a Manitoba Hydro research project. This robot is useful in solving maintenance problems in power systems. A description of the basic features of the LCR control system and basic architecture of a rough neurocomputing system for robot navigation are given. A sample LCR sensor signal classification experiment is also given. © Springer-Verlag Berlin Heidelberg 2002.

关键词： Electromagnetic fields

来源：评论

学校读者我要写书评

暂无评论

Stochastic modelling and AI techniques for power system reinforcements in a competitive energy market

Stochastic modelling and AI techniques for power system rein...

引用

2002 Fifth International Conference on Power system Management and control Conf. Publ. No. 488)

作者： T. Sangpetch K.L. Lo Division of System Control and Operation Electricity Generating Authority of Thailand Thailand Department of Electronic and Electrical Engineering University of Strathclyde UK

来源：评论

学校读者我要写书评

暂无评论

Software quality knowledge discovery: a rough set approach

Software quality knowledge discovery: a rough set approach

引用

IEEE Annual International Computer Software and Applications Conference (COMPSAC)

作者： S. Ramanna J.F. Peters T. Ahn Department of Business Computing University of Winnipeg Winnipeg MAN Canada Department of Electrical and Computer Engineering University of Manitoba Winnipeg MAN Canada Intelligent Information Control & System Lab School of Electrical & Electronic Engineering Wonkwang University Iksan South Korea

This paper presents a practical knowledge discovery approach to software quality and resource allocation that incorporated recent advances in rough set theory, parameterized approximation spaces and rough neural computing. In addition, this research utilizes the results of recent studies of software quality measurement and prediction. A software quality measure quantifies the extent, to which some specific attribute is present in a system. Such measurements are considered in the context of rough sets. This research provides a framework for making resource allocation decisions based on evaluation of various measurements of the complexity of software. Knowledge about software quality is gained when preprocessing during which, software measurements are analyzed using discretization techniques, genetic algorithms in deriving reducts, and in the derivation of training and testing sets, especially in the context of the rough sets exploration system (RSES) developed by the logic group at the Institute of Mathematics at Warsaw University. Experiments show that both RSES and rough neural network models are effective in classifying software modules.

关键词： Software quality Software measurement Resource management Rough sets Logic testing Set theory Algorithm design and analysis Genetic algorithms Software testing system testing

来源：评论

学校读者我要写书评

暂无评论

High Speed Indoor Navigation of Mobile Robots Using Hybrid Dynamic control Approach

引用

IFAC Proceedings Volumes 2001年第4期34卷 257-262页

作者： Mee-Seub Lim Sang-Rok Oh Joonhong Lim Dept. of Mechatronics Kyonggi Institute of Technology Intelligent System Control Research Center Korea Institute of Science and Technology Department of Electronic Engineering Hanyang University

In this paper, we propose a new approach to the high-speed navigation of the indoor environments for wheeled mobile robots using hybrid dynamic control approach. The proposed hybrid system consists of the discrete state system as the high-level process and the continuous state system as the low-level process. In discrete state system, the di crete states are defined by the user-defined constraints and the abstracted motions specify the reference motion commands of mobile robots. The experimental results show that hybrid system approach is an effective method for the autonomous navigation and highspeed maneuvering.

关键词： Mobile Robot High-Speed Indoor Navigation Hybrid Dynamic control

来源：评论

学校读者我要写书评

暂无评论

New development on tracking algorithm with derivation measurement

New development on tracking algorithm with derivation measur...

引用

IEEE International Conference on systems, Man and Cybernetics

作者： Yaping Dai Guanghui Yu Kotaro Hirasawa Department of Electrical and Electronic System Engineering Graduate School of Information Science and Electrical Engineering Kyushu University Japan Department of Automatic Control Beijing Institute of Technology China

We present a new observation model to improve the state estimation and prediction in a target tracking problems. There are two distinguished points in this approach. First, the measurement equation is set up in the polar coordinate and even combines the derivation measurement (range rate, azimuth rate, and elevation rate) with the usual position measurements (range, azimuth angle, and elevation angle). Next, the observation noise of sensor data is considered as a colored one and is being set up as a model of AR(1), by means of a pseudo measurement equation, and the requirement of Kalman filter can be satisfied. As a result, the accuracy of both the observation and prediction is increased.

关键词： Noise measurement Equations Coordinate measuring machines Colored noise Position measurement Target tracking Azimuth Radar tracking White noise Electric variables measurement

来源：评论

学校读者我要写书评

暂无评论

Table-comparison prefetching in VIA-based parallel file system

Table-comparison prefetching in VIA-based parallel file syst...

引用

Annual IEEE Symposium on Foundations of Computer Science

作者： Yoon-Young Lee Chei-Yol Kim Dae-Wha Seo Department of Electronic Engineering Kyungpook National University Daegu South Korea Computer System Research Department Electronics and Telecommunications Research Institute Daejeon South Korea

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：