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Improved response surface method based on sample point selection strategies

Journal of Harbin Institute of Technology(New Series) 2010年第6期17卷 756-760页

作者：李炜康海贵 State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology

In the reliability analysis of complex structures,response surface method(RSM)has been suggested as an efficient technique to estimate the actual but implicit limit state function.A set of sample points are needed to fit to the implicit *** has been noted that the accuracy of RSM depends highly on the so-called sample ***,the technique for point selection has had little *** the present study,an improved response surface method(IRSM)based on two sample point selection techniques,named the direction cosines projected strategy(DCS)and the limit step length iteration strategy(LSS),is *** it uses the sampling points selected to be located in the region close to the original failure surface,and since it needs only one response surface,the IRSM should be accurate and simple in practical structural *** to several typical examples have helped to elucidate the successful working of the IRSM.

关键词： sample points linear approximation method RSM reliability

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Design and Implementation of an FPGA-Based Digital Control IC of Maximum-Power-Point-Tracking Charger for Vertical-Axis Wind Turbine Generators

Design and Implementation of an FPGA-Based Digital Control I...

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8th International Conference on Power Electronics and Drive Systems (PEDS)

作者： Tsai, Ming-Fa Hsu, Wei-Chieh Wu, Tai-Wei Wang, Jui-Kum Minghsin Univ Sci & Technol Hsinchu Taiwan

ISBN: (纸本)9781424441662

This paper presents the design of an FPGA-based digital control IC of maximum-power-point-tracking (MPPT) charger for vertical-axis wind turbine generators. The output of the charger can be connected to a 48V battery to supply power to a DC load or an electric vehicle drive system. A novel MPPT scheme, which is the mixing of the conventional perturbation and observation method and a linear approximation method, to get the maximum output power of the wind turbine generation system with faster tracking speed is proposed. The simulation model of wind-turbine generation is built in PSIM simulation software tool and used to analyze the converter and MPPT system operation under different wind speed conditions. Based on the simulation model, the digital control IC of the MPPT charger is then designed. The digital MPPT control IC has been designed by using VHDL, hardware description language. The simulation models for the MPPT control IC have also been constructed and verified by using Simulink, ModelSim, and PSIM cosimulation tools. The designed circuit has been implemented on an Alters Cyclone FPGA logic device. Simulation and experimental results are shown to verify the viability of the proposed control IC of the MPPT charger.

关键词： Vertical-axis wind turbine generators MPPT FPGA digital control perturbation and observe method linear approximation method

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Stochastic resonance in a gain-noise model of a single-mode laser driven by pump noise and quantum noise with cross-correlation between real and imaginary parts under direct signal modulation

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CHINESE PHYSICS 2007年第1期16卷 123-129页

作者： Chen Li-Mei Cao Li Wu Da-Jin Shenzhen Univ Dept Phys Shenzhen 518057 Peoples R China Huazhong Univ Sci & Technol State Key Lab Laser Technol Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol China Ctr Adv Sci & Technol World Lab Wuhan 430074 Peoples R China

Stochastic resonance (SR) is studied in a gain-noise model of a single-mode laser driven by a coloured pump noise and a quantum noise with cross-correlation between real and imaginary parts under a direct signal modulation. By using a linear approximation method, we find that the SR appears during the variation of signal-to-noise ratio (SNR) separately with the pump noise self-correlation time tau, the noise correlation coefficient between the real part and the imaginary part of the quantum noise lambda(q), the attenuation coefficient. and the deterministic steady-state intensity I-0. In addition, it is found that the SR can be characterized not only by the dependence of SNR on the noise variables of t and lambda(q), but also by the dependence of SNR on the laser system variables of gamma and I-0. Thus our investigation extends the characteristic quantity of SR proposed before.

关键词： stochastic resonance direct modulation signal quantum noise with cross-correlation between real and imaginary part linear approximation method

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Stochastic resonance in a gain-noise model of a single-mode laser driven by pump noise and quantum noise with cross-correlation between real and imaginary parts under direct signal modulation

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Chinese Physics B 2007年第1期16卷 123-129页

作者：陈黎梅曹力吴大进 Department of Physics Shenzhen University Shenzhen 518057 China State Key Laboratory of Laser Technology Huazhong University of Science end Technology Wuhan 430074 China Department of Physics Huazhong University of Science and Technology Wuhan 430074 China Chine Centre of Advanced Science and Technology (World Laboratory) Beijing 100080 China

Stochastic resonance （SR） is studied in a gain-noise model of a single-mode laser driven by a coloured pump noise and a quantum noise with cross-correlation between real and imaginary parts under a direct signal modulation. By using a linear approximation method, we find that the SR appears during the variation of signal-to-noise ratio （SNR） separately with the pump noise self-correlation time τ, the noise correlation coefficient between the real part and the imaginary part of the quantum noise λq, the attenuation coefficient γ＇ and the deterministic steady-state intensity I0. In addition, it is found that the SR can be characterized not only by the dependence of SNR on the noise variables of and λq, but also by the dependence of SNR on the laser system variables of γ and I0. Thus our investigation extends the characteristic quantity of SR proposed before.

关键词： stochastic resonance direct modulation signal quantum noise with cross-correlation between real and imaginary part linear approximation method

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Stochastic resonance in single-mode semiconductor lasers

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PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2006年第1期368卷 31-37页

作者： Wang, J. Bai, Y. M. Cao, L. Wu, D. J. Ma, X. Y. Chinese Acad Sci Inst Semicond Natl Engn Res Ctr Optoelect Device Beijing 100083 Peoples R China Huazhong Univ Sci & Technol Dept Phys Wuhan 430074 Peoples R China Chinese Acad Sci Inst Semicond Key Lab Semicond Mat Sci Beijing 100083 Peoples R China

Owing to the considerable virtues of semiconductor lasers for applications, they have become the main optical source for fiber communication systems recently. The behavior of stochastic resonance (SR) in direct-modulated semiconductor laser systems is investigated in this article. Considering the carrier and photon noises and the cross-correlation between the two noises, the power spectrum of the photon density and the signal-to-noise ratio (SNR) of the modulated laser system were calculated using the linear approximation method. We found that the SR always appears in the dependence of the SNR upon the bias current density, and is strongly affected by the cross-correlation coefficient of the carrier and photon noises, the frequency of modulation signal and the photon lifetime in the laser cavity. Hence, it is promising to use the SR mechanism to enhance the SNR of direct-modulated semiconductor laser systems and improve the quality of optical communication. (c) 2006 Elsevier B.V. All rights reserved.

关键词： stochastic resonance carrier noise photon noise semiconductor lasers linear approximation method

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Stochastic resonance for bias signal-modulated noise in a single-mode laser

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PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2006年第1期366卷 159-166页

作者： Han, Li-Bo Cao, Li Wu, Da-Jin Wang, Jun Huazhong Univ Sci & Technol State Key Lab Laser Technol Wuhan 430074 Peoples R China Yangtze Univ Sch Phys Sci & Technol Hubei 434020 Peoples R China CCAST World Lab Beijing 100080 Peoples R China Huazhong Univ Sci & Technol Dept Phys Wuhan 430074 Peoples R China

By using the linear approximation method, the laser intensity power spectrum and signal-to-noise ratio (SNR) are calculated for a gain-noise model of a single-mode laser driven by colored cross-correlated pump noise and quantum noise, each of which is colored. We found that stochastic resonance(SR) appears in the behavior of the SNR versus not only the pump noise intensity and the self-correlation time, but also the bias current and the frequency of the signal. Moreover, a two-peaked SR occurs in the dependence of the SNR upon the self-correlation time when the cross-correlation coefficient between the both noises is positive, negative and zero, and the resonance peak is sharp. We also find both SR and suppression appear when the SNR varies with the frequency of the signal. (c) 2005 Published by Elsevier B.V.

关键词： linear approximation method colored cross-correlation noises bias signal modulation Stochastic resonance

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Influences of quantum noises on direct-modulated properties of 1.3-μm InGaAsP/InP laser diodes

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CHINESE PHYSICS 2006年第9期15卷 2125-2129页

作者： Wang Jun Ma Xiao-Yu Bai Yi-Ming Cao Li Wu Da-Jin Chinese Acad Sci Inst Semicond Natl Engn Res Ctr Optoelect Beijing 100083 Peoples R China Chinese Acad Sci Inst Semicond Key Lab Semicond Mat Sci Beijing 100083 Peoples R China Huazhong Univ Sci & Technol Dept Phys Wuhan 430074 Peoples R China

Due to the zero dispersion point at 1.3-mu m in optical fibres, 1.3-mu m InGaAsP/InP laser diodes have become main light sources in fibre communication systems recently. In fluences of quantum noises on direct-modulated properties of single-mode 1.3-mu m InGaAsP/InP laser diodes are investigated in this article. Considering the carrier and photon noises and the cross-correlation between the two noises, the power spectrum of the photon density and the signal-to-noise ratio (SNR) of the direct-modulated single-mode laser system are calculated using the linear approximation method. We find that the stochastic resonance (SR) always appears in the dependence of the SNR on the bias current density, and is strongly affected by the cross-correlation coeffcient between the carrier and photon noises, the frequency of modulation signal, and the photon lifetime in the laser cavity. Hence, it is promising to use the SR mechanism to enhance the SNR of direct-modulated InGaAsP/InP laser diodes and improve the quality of optical fibre communication systems.

关键词： InGaAsP/InP laser diodes carrier noise photon noise linear approximation method

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Influences of quantum noises on direct-modulated properties of 1.3-μm InGaAsP/InP laser diodes

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Chinese Physics B 2006年第9期15卷 2125-2129页

作者：王俊马骁宇白一鸣曹力吴大进 National Engineering Research Center for Opto-electronic Device Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Key Laboratory of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

Due to the zero dispersion point at 1.3μm in optical fibres, 1.3-μm InGaAsP/InP laser diodes have become main light sources in fibre communication systems recently. Influences of quantum noises on direct-modulated properties of single-mode 1.3-μm InGaAsP/InP laser diodes are investigated in this article. Considering the carrier and photon noises and the cross-correlation between the two noises, the power spectrum of the photon density and the signal-to-noise ratio （SNR） of the direct-modulated single-mode laser system are calculated using the linear approximation method. We find that the stochastic resonance （SR） always appears in the dependence of the SNR on the bias current density, and is strongly affected by the cross-correlation coefficient between the carrier and photon noises, the frequency of modulation signal, and the photon lifetime in the laser cavity. Hence, it is promising to use the SR mechanism to enhance the SNR of direct-modulated InGaAsP/InP laser diodes and improve the quality of optical fibre communication systems.

关键词： InGaAsP/InP laser diodes carrier noise photon noise linear approximation method

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Intensity correlation time of a single-mode laser driven by two coloured noises with coloured cross-correlation with direct signal modulation

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CHINESE PHYSICS 2005年第4期14卷 764-770页

作者： Chen, LM Cao, L Wu, DJ Wang, ZL Huazhong Univ Sci & Technol State Key Lab Laser Technol Wuhan 430074 Peoples R China Shenzhen Univ Dept Phys Shenzhen 518057 Peoples R China Huazhong Univ Sci & Technol Dept Phys Wuhan 430074 Peoples R China CCAST World Lab Beijing 100080 Peoples R China

In this paper, the intensity correlation time T is studied for the gain-noise model of a single-mode laser driven by coloured pump noise and coloured quantum noise with coloured cross-correlation with a direct signal modulation. By using the linear approximation method, it is found that when the pump noise is modulated directly by a signal, the effects of the cross-correlation between the pump noise and the quantum noise will disappear. In addition, there exists a maximum (i.e. resonance) in the curve of the intensity correlation time T versus the pump noise self-correlation time tau(1). Furthermore, when tau(1) < tau(2), the intensity correlation time T increases monotonically with the increase of D and decreases monotonically with the increase of Q, but when tau(1) > tau(2), the intensity correlation time T increases monotonically with the increase of Q and decreases monotonically with the increase of D.

关键词： intensity correlation time direct modulation signal linear approximation method

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Intensity Correlation Function of a Single-Mode Laser Driven by Colored Cross-Correlation Noises in Modulation of a Bias Signal

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Communications in Theoretical Physics 2005年第4期43卷 666-670页

作者： HANLi-Bo CAOLi YANGHong-Quan WUDa-Jin StateKeyLaboratoryofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China／／DepartmentofPhysicsYangtzeUniversityJingzhou434020China StateKeyLaboratoryofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China／／CCAST（WorldLaboratory）Beijing100080China DepartmentofPhysics YangtzeUniversityJingzhou434020China CCAST（WorldLaboratory） Beijing100080China／／DepartmentofPhysicsHuazhongUniversityofScienceandTechnologyWuhan430074China

By using the linear approximation method, the intensity correlation function is calculated for a single-mode laser modulated by a bias signal and driven by colored pump and quantum noises with colored cross-correlation. We found that, when the correlation time between the two noises is very short, the behavior of the intensity correlation function versus the time, in addition to decreasing monotonously, also exhibits several cases, such as one maximum, one minimum, and two extrema. When the correlation time between the two noises is very long, the behavior of the intensity correlation function exhibits oscillation and the envelope is similar to the case of short cross-correlation time.

关键词： linear approximation method intensity correlation function bias signal modulation oscillation

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