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International Conference on Advanced in Control Engineering and Information Science (CEIS)

作者： Wang Dian Liu Jinhao Wang Jianli Beijing Forestry Univ Beijing 100085 Peoples R China

For improving the working efficiency of the forestry harvester, a laser scanner was used to collect the 2-d scan data of the target living-trees. First of all, the noise of the scanning data are filtered with a extraction algorithm. Furthermore, the diameters of the living-trees are calculated out with the least square algorithm and the curve fitting. The results of the research and experiment show that the extraction algorithm the least square algorithm are accurate;the mean error of the calculation is 4.29 millimetre. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [CEIS 2011]

关键词： Laser Scan extraction algorithm least square algorithm curve fitting

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A Crosstalk Mitigation algorithm for OFDM-Carrying OAM Multiplexed FSO links

A Crosstalk Mitigation Algorithm for OFDM-Carrying OAM Multi...

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Opto-Electronics and Communications Conference (OECC) / Photonics Global Conference (PGC)

作者： Sun, Tengfen Liu, Minwen Li, Zhengxuan Li, Yingchun Zhang, Qianwu Wang, Min Shanghai Univ Shanghai Inst Adv Commun & Data Sci Key Lab Specialty Fiber Opt & Opt Access Networks Shanghai 200072 Peoples R China

ISBN: (纸本)9781509062935

In this paper, we experimentally demonstrate the performance of crosstalk mitigation for 16QAM-OFDM-carrying OAM multiplexed FSO links by using the pilot assisted least square (LS) algorithm. Crosstalk is introduced by demodulation holograms with random turbulent phase screen at the demodulation SLMs. Experimental results show that the proposed algorithm can efficiently improve the quality of constellations and reduce the bit-error rate (BER), and similar to 10 dB sensitivity improvement is obtained.

关键词： component Orbital angular momentum OFDM Channel equalization least square algorithm

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Realization of the Instantaneous Frequency Measurement Employing the least square algorithm on DSP

Realization of the Instantaneous Frequency Measurement Emplo...

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2011 International Conference on Computers, Communications, Control and Automation

作者： WANG Lian-shi YAO Zhen-dong School of Electrical Engineering Chengdu University of Information Technology

ISBN: (纸本)9781612841021

At present, most oscillators of the radar transmitter are magnetron because of its simple and convenience. However, because of the instability of frequency, it is difficult to meet the requirement of the modern Doppler radar. In this paper, we employ the least square method to realize the real-time measurement of the radar transmission frequency, and make the magnetron meet the requirement of the modern Doppler radar. We implement the algorithm in the fixed-point DSP TMS320C5402 and MATLAB, and compare the two results, which prove that the accuracy of the least square algorithm realized in DSP meets the requirement of projects.

关键词： Doppler radar instantaneous frequency measurement least square algorithm fixed-point DSP

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Diameter Fitting by least square algorithm Based on the Data Acquired with a 2-D Laser Scanner

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Procedia Engineering 2011年 15卷 1560-1564页

作者： Wang Dian Liu Jinhao Wang Jianli Beijing Forestry University Hai Dian District Beijing and 100085 China

For improving the working efficiency of the forestry harvester, a laser scanner was used to collect the 2-d scan data of the target living-trees. First of all, the noise of the scanning data are filtered with a extraction algorithm. Furthermore, the diameters of the living-trees are calculated out with the least square algorithm and the curve fitting. The results of the research and experiment show that the extraction algorithm the least square algorithm are accurate; the mean error of the calculation is 4.29 millimetre.

关键词： Laser Scan extraction algorithm least square algorithm curve fitting

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Calibration for frequency-dependent mismatches in bandpass sampling TIADCs

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IEICE ELECTRONICS EXPRESS 2017年第19期14卷 20170851-20170851页

作者： Li, Nan Liu, Xiangyu Liu, Husheng Wang, Yinan Natl Univ Def Technol Coll Elect Sci 109 Deya Rd Changsha 410073 Hunan Peoples R China

Bandpass sampling (BPS) is a widely used technique where one samples a bandpass-filtered signal at a sampling rate below its Nyquist rate (twice the upper cutoff frequency). For a BPS time-interleaved ADC (TIADC), its dynamic range is subject to the frequency-dependent mismatches generally introduced by the differences of process, supply voltage and temperature between constituent ADCs. This paper proposes a calibration method for frequency-dependent mismatches in BPS TIADCs. The frequency-dependent mismatches is analyzed in both time and frequency domain with the aid of Taylor's series and binary Hadamard transform (BHT). The calibration is composed of coefficients estimation, equalization and mismatches compensation. The coefficients are estimated by solving a linear equations in the foreground based on least square (LS) algorithm. Equalization is to cancel out the linear distortion ahead of compensation to provide a better approximation of the input signal. The principle of mismatches compensation is to reconstruct the mismatches-induced spurious components and subtract them from the original TIADC's output. Simulation results are provided to show the improvement of both effective resolution and dynamic range, and investigate the proper length of training signal, the proper order of Taylor approximation, differentiator and Hilbert filter.

关键词： TIADC bandpass sampling frequency-dependent mismatches least square algorithm binary Hadamard transform differentiator

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Research and Analysis on the Localization of a 3-D Single Source in Lossy Medium Using Uniform Circular Array

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SENSORS 2017年第6期17卷 1274-1274页

作者： Xue, Bing Qu, Xiaodong Fang, Guangyou Ji, Yicai Chinese Acad Sci Inst Elect Key Lab Electromagnet Radiat & Sensing Technol Beijing 100190 Peoples R China Univ Chinese Acad Sci Beijing 100039 Peoples R China

In this paper, the methods and analysis for estimating the location of a three-dimensional (3-D) single source buried in lossy medium are presented with uniform circular array (UCA). The mathematical model of the signal in the lossy medium is proposed. Using information in the covariance matrix obtained by the sensors' outputs, equations of the source location (azimuth angle, elevation angle, and range) are obtained. Then, the phase and amplitude of the covariance matrix function are used to process the source localization in the lossy medium. By analyzing the characteristics of the proposed methods and the multiple signal classification (MUSIC) method, the computational complexity and the valid scope of these methods are given. From the results, whether the loss is known or not, we can choose the best method for processing the issues (localization in lossless medium or lossy medium).

关键词： uniform circular array source localization least square algorithm lossy medium

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Loss-of-excitation analysis and protection for pumped-storage machines during starting

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IET RENEWABLE POWER GENERATION 2016年第1期10卷 71-78页

作者： Li, Bin Duan, Zhitian Wang, Xin Wu, Jianzhong Tianjin Univ Key Lab Smart Grid Minist Educ Tianjin 300072 Peoples R China Tianjin Elect Power Co Customer Serv Ctr Tianjin 300010 Peoples R China Cardiff Univ Inst Energy Cardiff Sch Engn Cardiff CF24 3AA S Glam Wales

The reversible synchronous machines in a pumped station are put into operation frequently for effective operation of the hydro pumped-storage system. The detection of loss-of-excitation (LOE), which is a common failure for synchronous machines, must be guaranteed not only in normal operation, but also under starting and other possible operation conditions. A model of pumped-storage units under the starting condition was developed using the SimPowerSystems in Matlab/Simulink. The simulation results and real tests of a pumped-storage power plant in northeast China were presented. The LOE characteristics during starting were analysed for the first time. Since the frequency of voltage and current runs up gradually from zero to the rated frequency during starting, conventional LOE protections based on impedance under the rated frequency have to be disabled during starting. For this reason, a novel LOE protection was developed based on the R-L time-domain model and the least-square algorithm. Theoretical analysis and simulation tests demonstrate that the proposed LOE protection method is correct and valid.

关键词： synchronous machines pumped-storage power stations starting time-domain analysis least mean squares methods power system protection pumped storage machine reversible synchronous machine pumped station hydro pumped-storage system loss-of-excitation starting condition SimPowerSystems pumped storage power plant LOE protection R-L time-domain model least square algorithm

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Three-dimensional measurement of multilayer thin films based on scanning white light interferometer 8

Three-dimensional measurement of multilayer thin films based...

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8th International Symposium on Advanced Optical Manufacturing and Testing Technology (AOMATT) - Optical Test, Measurement Technology, and Equipment

作者： Shi Zhendong Zhang Lin Ren Huan Yuan Quan Yang Yi Ma Hua CAEP Res Ctr Laser Fus 64 Mianshan Rd Mianyang 621900 Peoples R China

ISBN: (纸本)9781628419191

For multilayer films system, in order to obtain the thickness and surface profile in each layer of thin film, a method to measure the 3D morphology of a multilayer films system based on scanning white light interferometer has been proposed in this article. At first, the mathematical relationship between reflection phase and thickness of each film layer has been obtained by using the electromagnetic field boundary conditions. Then, a nonlinear least square algorithm has been used to fit the reflection phase which had been found through a scanning white light interferometer, in this way the linear and nonlinear terms of the reflection phase have been separated, which made it possible to measure top-layer surface profile and thickness of each thin film layer respectively and avoided the interference with each other, because the linear term is related to the top layer's surface profile but the nonlinear term is correlated to the thickness of each film layer in multilayer thin films system. Thus, the three-dimensional morphology of multilayer thin films system could be reconstructed. Experimental results showed this method was effective in the three-dimensional morphology measurement for multilayer thin films. And the measurement could be completed just using the existing commercial scanning white light interferometer, as a consequence the measurement cost is low, and the operation will be quite simple.

关键词： Film measurement white light interferometer multilayer thin films least square algorithm

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ARMAX Time Delay Systems Identification Based on least square Approach

ARMAX Time Delay Systems Identification Based on Least Squar...

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17th IFAC Symposium on System Identification (SYSID 2015)

作者： Bedoui, Saida Abderrahim, Kamel Gabes Univ Natl Engn Sch Gabes Res Unit Numer Control Ind Proc Route MedenineBP 6029 Gabes Tunisia

In this paper, an algorithm is developed for the identification of the time delay parameter and the dynamic parameters of autoregressive moving average with exogenous input ARMAX time delay models. This algorithm consists in constructing a linear-parameter formulation by building a generalized vector observation and using the recursive least squares approach to solve the obtained system. Simulation and experimental test results are presented to illustrate the performance of the proposed approach. (C) 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Time Delay Systems System Identification Discrete-time least square algorithm

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Determination of automobile paint thickness using non-contact THz-TDS technique 40

Determination of automobile paint thickness using non-contac...

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40th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

作者： Hernandez-Serrano, A. I. Castro-Camus, E. Ctr Invest Opt AC Loma del Bosque 115 Leon 37150 Guanajuato Mexico

ISBN: (纸本)9781479982721

We use pulsed THz-TDS as a non-contact method for the measurement of thickness in automobile paint on a non-metallic substrate. We use a least square algorithm in order to fit the reflected pulses of each layer. Extracting the delay of each from the theoretical function allows us to know the thickness of each layer present in the system.

关键词： automobiles least squares approximations thickness measurement automobile paint thickness determination delay extraction least square algorithm noncontact THz-TDS technique nonmetallic substrate pulse reflection Automobiles Automotive engineering Delays Industries Paints Pulse measurements Thickness measurement

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