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International Conference on Fuzzy systems and Knowledge Discovery (FSKD)

作者： Jia, L.V. Chongqing Key Lab. of Operations Research and System Engineering College of Computer and Information Science Chongqing Normal University Chongqing 400047 China

ISBN: (纸本)9781424459346

According to the problem that K-Means clustering algorithm fails to correctly distinguish non-convex shape clusters, computation mode of distance in the algorithm is changed and density metric mode which can reflect the characteristics of data themselves is adopted instead. In the mode, Delaunay triangulation graph which has the advantages of nearest neighbour and adjacency is introduced to compute density. Simultaneously, because K-Means clustering algorithm itself belongs to a global optimization problem, chaos optimization dedicated to global optimization is applied to optimize objective function for the sake of obtaining global minimum solution. Experiments results indicate that clustering algorithm based on Delaunay triangulation density metric can find arbitrary non-convex shape clusters. ©2010 IEEE.

关键词： Clustering algorithms

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A novel clustering algorithm based on multi-sampling max-min distance and dynamic tunneling method

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Journal of Information and Computational Science 2009年第2期6卷 637-642页

作者： Lv, Jia Chongqing Key Lab. of Operations Research and System Engineering College of Mathematics and Computer Science Chongqing Normal University Chongqing 400047 China

In view of the limitations that k-means clustering algorithm is sensitive to the initial points and liable to fall into local minimum point, a clustering algorithm based on multi-sampling max-min distance and dynamic tunneling method is proposed. In this algorithm, max-min distance approach combined with multi-sampling technology is used to choose the starting cluster centers optimally, and dynamic tunneling method, whose feature is its ability to search global optimum solution, is applied to skip through local minima of objective function via drilling tunnel. It is proved validity and feasibility by experiment. Copyright ©2009 Binary Information Press.

关键词： Global optimization

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An electrical energy meter for electric vehicle charging machines based on FFT and wavelet analysis

An electrical energy meter for electric vehicle charging mac...

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2014 International Symposium on Fundamentals of Electrical engineering, ISFEE 2014

作者： Fuping, Zhao Rongmei, Liu Bei, He Yan, Hui Electric Power Research Institute Chongqing Power Company ChongQing400044 China State Key Lab. of Transmission and Distribution Equipment and System Security and New Technology School of Electrical Engineering Chongqing University Chongqing400044 China

ISBN: (纸本)9781479968213

More and more electric vehicles have been used in China, and many charging station has been built in China. Due to the reactive power loss caused by charging devices, the method to measure the power consumed by charging device is critical for power *** on impact loads generated by electric vehicles to the grid in fast charging mode, this paper studies the energy measurement method of electric vehicle charging mode. By comparing the fast Fourier transform and wavelet analysis algorithms, an electric energy measurement device of electric vehicle charging machine based on FFT and wavelet analysis are proposed. Combined with fast data processing functions of DSP, the device can quickly and accurately measures electric vehicles charging amounts under different charging modes. © 2014 IEEE.

关键词： Fast Fourier transforms

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research about the power consumption detection technology of charger considering the harmonic and unbalanced current

Research about the power consumption detection technology of...

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2014 International Symposium on Fundamentals of Electrical engineering, ISFEE 2014

作者： Ke, Zheng Xiaorui, Hu Jing, Ji Kai, Liu State Grid Chongqing Electric Power Corporation Research Institute Chongqing40000 China State Key Lab. of Transmission and Distribution Equipment and System Security and New Technology School of Electrical Engineering Chongqing University Chongqing400044 China

ISBN: (纸本)9781479968213

In this paper, an electric vehicle charging posts(charger) power consumption detection technology based on harmonic wave and preventing leakage circuit breaker current imbalance technology is proposed. Firstly, for the working characteristics of electric vehicle charging posts, by studying harmonic characteristics produced by electric car charging posts, this paper analyzes harmonic effects on power measurement. And based on the Fast Fourier Transform (FFT) principle, the harmonic energy measurement method of car charging posts is studied. Since each phase current of charging post imbalance, to prevent the sum of each phase current vector of charging posts over the protection current threshold and the charging post breaker misusing in power circuit, preventing leakage circuit breaker current imbalance system is designed. Finally, this paper studies the power consumption detection methods of electric vehicle charging posts, and designs charging post power metering device. © 2014 IEEE.

关键词： Electric power utilization

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Virtual flux based direct power control for three-level PWM rectifier 17

Virtual flux based direct power control for three-level PWM ...

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2014 17th International Conference on Electrical Machines and systems, ICEMS 2014

作者： Yingchao, Zhang Liping, Jin Yongchang, Zhang Ting, Lu Zhengming, Zhao Key Lab. of Special Power Supply of PLA Chongqing Communication Institute China North China University of Technology Power Electronics and Motor Drive Engineering Research Center China State Key Lab. of Control and Simulation of Power System and Generation Equipments Tsinghua University China

ISBN: (纸本)9781479951611

This paper presents a new control strategy for three-level neutral point clamped (NPC) pulse width modulated (PWM) rectifier without power source voltage sensors. The relationship between instantaneous power and voltage vectors is derived mathematically. Virtual flux is estimated and used to calculate the phase of the power source voltage and instantaneous power. On these bases, a direct power control (DPC) scheme for three-level PWM rectifier is presented. An optimal switching table is established, vector switching scheme and balance strategy for the neutral point potential are discussed. Variable switching frequency and dynamic process of the startup are also analyzed. Experimental results have verified the theoretical approach and the three-level PWM rectifier with proposed DPC based on virtual flux exhibits several advantages, such as simple algorithm, low costs and excellent dynamic performance. © 2014 IEEE.

关键词： Electric rectifiers

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A new fault diagnosis method based on damped least square QR-factorization algorithm in grounding grid

A new fault diagnosis method based on damped least square QR...

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2014 International Symposium on Fundamentals of Electrical engineering, ISFEE 2014

作者： Degui, Yao Xiaokuo, Kou Guangjie, Zhu Fan, Yang Feng, Dai Kai, Liu Jiajia, Hu Electric Power Research Institute Henan Power Company Zheng Zhou Henan450000 China State Key Lab. of Transmission and Distribution Equipment and System Security and New Technology School of Electrical Engineering Chongqing University Chongqing400044 China

ISBN: (纸本)9781479968213

With the development of power system and the constant attention to the security of equipment and personnel, fault diagnosis of grounding grid gets more and more attention. In this paper, a new fault diagnosis method for grounding grid based on damped least square QR-factorization algorithm is presented. Firstly, a magnetic field reconstruction method based on the magnetic field method is presented and then a calculation method for magnetic field above grounding grid is proposed. Afterwards, in order to solve the ill-posed reconstruction equations, a damped least squares QR-factorization algorithm is used. Finally, a simulation example is used to verify the feasibility and accuracy of the algorithm. The simulation results show that the reconstructed magnetic field and actual magnetic field are very close;the reconstruction method can also be used when the original data have some errors. So the magnetic field reconstruction method in this paper can be applied to fault diagnosis of grounding grid. © 2014 IEEE.

关键词： Failure analysis

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Study of microfluidic chip with in-situ prepared chitosan membrane immobilized with glucose oxidase

Study of microfluidic chip with in-situ prepared chitosan me...

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Micro and Nano Technology - 1st International Conference Society of Micro/Nano Technology, CSMNT

作者： Qiang, Cao Yi, Xu Defu, Song Weiwei, Han Xizhe, Dong Key Disciplines Lab. of Novel Micro-Nano Devices and System Technology International R and D Center of Micro-Nano Systems and New Materials Technology Microsysten Research Center Chemistry and Chemical Engineering College Chongqing University Chongqing 400030 China

ISBN: (纸本)0878493395

A microfluidic chip with in-situ prepared chitosan membrane immobilized with Glucose Oxidase was developed as glucose oxidase reactor to detect human serum. The chitosan was prepared in-situ in the micro-channel as the immobilization ***,GOD was immobilized in the chitosan membrane, in which factors, such as the glutaraldehyde concentration, time of crosslinking and immobilization, buffer pH, were optimized with orthogonal experiments. The concentration of glutaraldehyde was finally chosen as 0.15%, time of crosslinking as 60 min, immobilization time as 15 h, and buffer PH as 8.0. The immobilization efficiency could reach up to 5U·cm2. The homemade microchip could be applied for rapid determination of glucose in serum, combining with the Luminol-K3uL·min-1, the concentration of K3Fe(SCN)3 of 1 × 10 -2mol·L-1 and the concentration of luminol of 5×10-1 mol·L-1, the detection limit could achieved lug·mL-1. © 2009 Trans Tech Publications, Switzerland.

关键词： Microfluidic chips

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Stability of Hybrid Impulsive systems With Time Delays and Stochastic Effects

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IFAC Proceedings Volumes 2008年第2期41卷 5933-5938页

作者： Zhichun Yang Yiguang Hong Key Laboratory of Systems and Control Institute of Systems Science Chinese Academy of Sciences Beijing 100080 China Chongqing Key Lab of Operations Research and System Engineering Department of Mathematics and Computer Science Chongqing Normal University Chongqing 400047 China

In this paper, a class of hybrid impulsive systems with time delays and stochastic effects are considered. We obtain some criteria on the global exponential stability in mean square for the impulsive stochastic delayed systems. To do this, differential inequalities and ℒ-operator inequalities are developed. An example is given to illustrate the effectiveness of our results.

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A Polyimide Diaphragm-Based Extrinsic Optical Fiber Fabry-Perot Acoustic Sensor for the Detection of High-Frequency Ultrasonic Signals in Transformer Oil 7

A Polyimide Diaphragm-Based Extrinsic Optical Fiber Fabry-Pe...

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7th IEEE International Conference on High Voltage engineering and Application, ICHVE 2020

作者： Qian, Guochao Peng, Qingjun Peng, Hui Wang, Shuchao Zhang, Zhixian Lei, Jiali Electric Power Research Institute Yunnan Power Grid Limited Company Kunming China Yunnan Transformer Electric Limited Company Kunming China State Key Lab. of Transmission Distribution Equipment and Power System Safety and New Technology School of Electrical Engineering Chongqing University Chongqing China

ISBN: (纸本)9781728155111

This article shows an extrinsic optical fiber Fabry-Perot (F-P) acoustic sensor based on a polyimide diaphragm whose effective vibration area and thickness respectively are approximate 4.906 mm2 and 8.5\ \mu \mathrm{m} for the high-quality detection of high-frequency ultrasonic signals in transformer oil. Directional test indicates this proposed sensor is an omnidirectional sensor. And experimental results of the detection for high-frequency ultrasonic signals in transformer oil indicate this proposed sensor has a flat frequency response, which demonstrates this proposed sensor can achieve the high-quality detection for high-frequency ultrasonic signals in transformer oil. Therefore, this proposed sensor also has excellent potential for the detection of partial discharges occurring in transformer oil in any direction. © 2020 IEEE.

关键词： Frequency response

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A Sensitivity-Enhanced Fiber Grating Voltage Sensor Based on Giant Magnetostrictive Material Applied for Voltage Detection 7

A Sensitivity-Enhanced Fiber Grating Voltage Sensor Based on...

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7th IEEE International Conference on High Voltage engineering and Application, ICHVE 2020

作者： Wang, Shuchao Yang, Wenlong Zhou, Quan Chen, Weigen Xiong, Yanling Liu, Fan State Key Lab. of Transmission Distribution Equipment and Power System Safety and New Technology School of Electrical Engineering Chongqing University Chongqing China Major of Optoelectronic Information and Science School of Science Harbin University of Science and Technology Department of Physics Harbin China Electric Power Research Institute Hubei Power Grid Limited Company Wuhan China

ISBN: (纸本)9781728155111

This article shows a sensitivity-enhanced fiber grating voltage sensor based on giant magnetostrictive material using the edge demodulation system of multiple coarse wavelength division multiplexers (CWDMs). We firstly verified any number of CWDMs in series within 19 can enhance the sensitivity of this proposed sensor in theory. And the experimental result of voltage detection indicates this sensitivity of the sensor by using two CWDMs randomly as the demodulation system is 1.54 times that of this sensor by using a CWDM as the demodulation system, namely, the sensitivity of the proposed sensor can indeed be enhanced by using any two CWDMs as the demodulation system. This work opens a door for the practical usage of this proposed sensor in high-voltage detection of power grids. © 2020 IEEE.

关键词： Fiber Bragg gratings

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