检索结果-内蒙古大学图书馆

Pan Tao Ti Hsueh Pao/Chinese Journal of Semiconductors 2008年第5期29卷 998-1002页

作者： Shi, Yunfen Shi, Yunbo Sun, Mojie Feng, Qiaohua School of Chemical Engineering Northeast Dianli University Jilin 132012 China College of Measure-Control Technology and Communication Engineering Harbin University of Science and Technology Harbin 150080 China

Aimed at the problem of quickly detecting phosphorus-containing toxic gas, we used home-made hybrid PdPc-PANI as the material for sensitive film and designed a binary channel SAW sensor. We expound the basic principle of the sensor and deduce that when using organic film as the intermediate medium of channel, different frequency output Δf was superimposed by a mathematical model using the two mechanisms of physical chemistry adsorption. According to the conditions of sound wave oscillation, we designed a signal gathering circuit whose oscillation frequency is 146 ± 5 MHz. Using lithium tantalate as piezoelectric substrate, through MEMS micro-fabrication we made finger-cross electrodes couple and hot film. We adopted vacuum deposition technology to make material of sensitive film into film, which modified the center of the SAW channel to compose the SAW sensor. The testing result indicates that when material has the best sensitivity, the mixture ratio is PdPc0.35PANI0.65. When the chip is heated to 60-80C, it can increase the performance, the responsive time is less than or equal to 30 s;The gas concentration of output and testing is consistent with that in the mathematic model, and is the N-style linear relation of linear change rate -110 kHz (mg/m3). The SAW sensor counteracts the interference of gasoline oil and carbon dioxide and so on;Through the checking of stability for 80 days, Δf is less than or equal to +0.1 kHz, which meets the requirement for practical use.

关键词： Phosphorus

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Pulse injection testing for LD chip LIV characteristics

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Dalian Haishi Daxue Xuebao/Journal of Dalian Maritime University 2008年第3期34卷 38-42页

作者： Fan, Xian-Guang Tang, Wen-Yan Xu, Wen-Hai Department of Automatic Measurement and Control Harbin Institute of Technology Harbin 150001 China College of Information Engineering Dalian Maritime University Dalian 116026 China

A method based on pulse injection was put forward to test the light-current-voltage (LIV) characteristics of laser diode (LD), and a new type of pulse measurement system was developed. The system provided pulsed current with continuously adjustable pulse width, pulse cycle and pulse amplitude to the measured LD, and collected the data generated from forward current, terminal voltage, backlight current and optical power of LDs under automatic power control or automatic current control, and then the LIV characteristics curves of LD were plotted based on above data, and the performance of LD was deduced. The pulsed current with low duty ratio effectively inhibited the temperature increasing in the active region of LD, which guaranteed the accuracy and reliability of the tests. Experimental results show that the stability of forward pulse current can reach 10-4, which meet the requirements for the LIV testing system, and its performance is superior to the DC testing system.

关键词： Power control

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Video Key Frame Extraction Based on Spatial-Temporal Color Distribution

Video Key Frame Extraction Based on Spatial-Temporal Color D...

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International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIHMSP)

作者： Zhonghua Sun Kebin Jia Hexin Chen College of Electronic Information & Control Engineering Beijing University of Technology China Communication Engineering College Jilin University China

Video key frame extraction is a type of video abstraction, which is one of the key problems in video content indexing and retrieval. Key frame extraction aims at finding a small collection of salient images extracted from a video sequence for visual content summarization. In this paper we propose a video key frame extraction method based on spatial-temporal color distribution. First we construct a temporally maximum occurrence frame which considers the spatial and temporal distribution of the pixels throughout the video shot. Then a weighted distance is computed between frames in the shot and the constructed reference frame. Key frames are extracted at the peaks of the distance curve and can achieve high compression ratio and high fidelity.

关键词： Distance measurement Pixel Histograms Image color analysis Data mining Streaming media Equations

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An adaptive observer-based nonlinear control for chaos synchronization

An adaptive observer-based nonlinear control for chaos synch...

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International Symposium on Systems and control in Aerospace and Astronautics (ISSCAA)

作者： Lilian Huang Qitian Yin Guanghui Sun Linyu Wang Yongqing Fu College of Information and Communication Engineering Harbin Engineering of Technology Harbin China Space Control and Inertial Technology Research Center Harbin Engineering of Technology Harbin China

This paper presents a control scheme for the synchronization of chaotic systems when the same chaotic system with the different initial conditions. For a given chaotic system, an adaptive observer-based response can be constructed to synchronize the drive system. Moreover this scheme uses the nonlinear controller which is achieved the global synchronization and the proposed controller doesnpsilat need the nonlinear function satisfies the Lipschitz condition. Theoretical analysis and numerical simulation on Chen system show the effectiveness and efficiency of the proposed scheme.

关键词： Programmable control Adaptive control Chaos Chaotic communication control systems communication system control Nonlinear control systems Paper technology Adaptive systems Sliding mode control

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Blind Separation Algorithm for Audio Signal Based on Genetic Algorithm and Neural Network

Blind Separation Algorithm for Audio Signal Based on Genetic...

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International Symposium on Information Science and engineering, ISISE

作者： Dahui Li Ming Diao Xuefeng Dai Compute and Control Engineering Institute Qiqihar University Qiqihar Heilongjiang China College of Information and Communication Engineering Harbin Engineering of Technology Harbin Heilongjiang China

The blind separation of audio signal is an important application of blind signal separation technology. The traditional separation algorithm based on neural network is analyzed first in this article. The shortage of it is easy to fall into local minimum, and it causes the limitation of convergence slowly and separation results inaccurate. Then, a separation algorithm is designed with genetic algorithm and neural network. The algorithm will optimize the initial value of the weight of separation, in order to control the sample by select operation, or cross operation, or mutation operation in the entire search space. Experiments show that it can obtain optimal values for separation matrix, and the speed of audio signal blind separation is quick and effective obviously.

关键词： Genetic algorithms Neural networks Signal processing algorithms Algorithm design and analysis Backpropagation algorithms Genetic engineering Blind source separation Radar signal processing Convergence Source separation

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Adaptive synchronization of different dimensional chaotic systems with unknown parameters

Adaptive synchronization of different dimensional chaotic sy...

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International Symposium on Systems and control in Aerospace and Astronautics (ISSCAA)

作者： Guanghui Sun Mao Wang Lilian Huang Space Control and Inertial Technology Research Center Harbin Institute of Technology Harbin Heilongjiang China College of Information and Communication Engineering Harbin Engineering University 150001 Heilongjiang Province China

This work presents the adaptive synchronization between two different order chaotic systems with unknown parameters. Based on Lyapunov stability theory, a novel adaptive control law and a parameter update rule for unknown parameters are proposed. The proposed scheme can successfully synchronize some typical chaotic systems, such as the hyperchaotic Chen system and the Duffing equation. Numerical Simulation results verify the proposed schemepsilas effectiveness. Furthermore, the estimated values of the parameters are not identical to the real values under our discussions.

关键词： Chaos Lyapunov method Adaptive control Equations Numerical simulation

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A Care communication System with Space Sharing Function

A Care Communication System with Space Sharing Function

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International Conference on Advanced Information Networking and Applications (AINA)

作者： Akio Koyama Yosuke Takenaka Junpei Arai Leonard Barolli Department of Informatics Graduate Yamagata University Japan Department of Information and Control Engineering Yamagata College of Industry and Technology Japan Department of Information and Communication Engineering Fukuoka Institute of Technology Japan

Recently there are a lot research works for multimedia communication systems. Especially, the space sharing communication is one of research trends for multimedia communication. By using the space sharing technology, the users feel as they are in the same space, even if they are in different locations. This can be done taking each video image of two remote points into one space. In this paper, we propose a care communication system with space sharing function. The implemented care communication system supports the communication and information sharing among in-patients, family members, doctors and helpers. In the proposed system, we have developed not only integration of two video images but also a warmth transmission function. By using this function, two persons in different locations can transmit their feelings as they are in the same space. We verified the proposed system effectiveness by conducting some experiments.

关键词： Space technology Video sharing Multimedia communication Multimedia systems Medical treatment Medical services Informatics control engineering Educational institutions Aerospace industry

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Minimisation of harmonics amplification due to resonance by relocation of capacitors using ADALINE on a DSP

Minimisation of harmonics amplification due to resonance by ...

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International Conference on Computing, communication and Networking, ICCCN

作者： K.R. Valluvan A. Vetrivel A.M. Natarajan Jovitha Jerome Department of Information Technology Kongu Engineering College Erode India Department of Electrical and Electronics Engineering Institute of Road and Transport Technology Erode India Dept. of Electronics & Communication Engineering Bannari Amman Institute of Technology Sathyamangalam India Department of Instrumentation and Control Systems Engineering PSG College of Technology Coimbatore India

Nonlinear loads produce current harmonics. The harmonic current flowing through the nonzero impedance of the electrical network, produce harmonics in supply voltage. Harmonics in power systems cause many ill effects and economic losses. To minimise the losses, IEEE: 519- 1992 has specified limits on voltage and current harmonics. Inductive loads like induction motors produce lagging power factor of less than unity. Capacitors are often used to improve the power factor by adding them in shunt with inductive loads. When high frequency harmonic currents flow through the network, due to the combination of inductive and capacitive loads (which are linear), resonance occurs. This causes an amplification of harmonics. Consequently, the increased harmonics affect the linear loads and produce more losses. This paper explains the results of harmonics measurements by a class of neural network, ADALINE implemented on a digital signal processor. measurements were carried out when capacitors were grouped in one place and after their relocation nearer to the linear loads. The results show that, relocation of capacitors have minimised both voltage and current harmonics significantly. This methodology is very economical since it does not require any additional equipment for filtering of harmonics.

关键词： Resonance Capacitors Digital signal processing Power system harmonics Power harmonic filters Voltage Power generation economics Reactive power Impedance Power system economics

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Takagi-Sugeno Fuzzy Coordinated control System with Original Plant Fuzzy State Observer for a Power Unit

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IFAC Proceedings Volumes 2008年第2期41卷 13205-13210页

作者： Xiu-chun Luan Wei-shi Han Ai-guang Young Yu Zhai Yu Jiang College of Nuclear Science and Technology Harbin Engineering University Harbin Heilongjiang Province 150001 China (Tel: +86-451-82838188 Department of Control Science and Engineering Harbin Institute of Technology Harbin Heilongjiang Province 150001 China College of Information Science and Technology Qingdao University of Science and Technology Qingdao Shandong Province 266061 China School of Economic Management Harbin University of Science and Technology Harbin Heilongjiang Province 150040 China Information And Communication Engineering College Harbin Engineering University Harbin Heilongjiang Province 150001 China

The Takagi-Sugeno (T-S) fuzzy multiple-variable integral control system with fuzzy state observer is designed for the coordinated control of multi-input-multi-output (MIMO) nonlinear boiler-turbine system whose operating points vary within a wide range. Linear models are first derived from the original nonlinear model on several operating points. Next the fuzzy multi-variable integral controller and the fuzzy state observer are designed via using the parallel distributed compensation (PDC) scheme, and the T-S fuzzy control system is constructed with the drum pressure as the premise variable. The problem that part of state variables can not be measured is successfully solved by introducing fuzzy state observer. Last the stability analysis is given by means of linear matrix inequality (LMI) approach, and the control system is guaranteed to be stable within a large range. The simulation results demonstrate that the control system works well over a wide region of operation.

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A Design of Time-Varying Auto-Adaptive Tracker

A Design of Time-Varying Auto-Adaptive Tracker

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ISECS International Colloquium on Computing, communication, control, and Management, CCCM

作者： Xianfang Wang Zhiyong Du Feng Pan Henan Institute of science and technology Xinxiang Henan China School of Communication & Control Engineering Jiangnan University Wuxi Jiangsu China Department information Engineering College of Henan Mechanical and Electrical Engineering Xinxiang Henan China

According to the unknown control direction strict feedback nonlinear systems, this paper introduced a design process for time-varying nonlinear adaptive controller by introducing the Nussbaum increasing and the dead area revision algorithm. Its stability is proved and analyzed, and its simulation is designed with the LMI MATLAB toolbox, the result shows that the controller has a good performance.

关键词： Artificial neural networks Nonlinear systems Algorithm design and analysis Adaptive control control systems Stability analysis Time varying systems

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