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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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Asymptotic behavior of best approximations of classes of Poisson integrals of functions from H_ω

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JOURNAL OF approximation THEORY 2011年第11期163卷 1692-1706页

作者： Serdyuk, A. S. Sokolenko, I. V. Ukrainian Natl Acad Sci Inst Math UA-01601 Kiev 4 Ukraine

We find asymptotic formulas for the least upper bounds of approximation in the metric of the space C by using a linear method U*(n) for classes of Poisson integrals of continuous 2 pi-periodic functions in the case where their moduli of continuity do not exceed fixed convex majorants. On the basis of these results, we obtain asymptotic formulas for the best uniform approximations by trigonometric polynomials and, under some restrictions, asymptotic formulas for Kolmogorov widths of these classes in the uniform metric. (C) 2011 Elsevier Inc. All rights reserved.

关键词： Poisson integral Modulus of continuity Best approximation linear approximation method Kolmogorov-Nikol'skii problem Kolmogorov width

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ESTIMATION OF STATISTICAL MOMENTS AND STEADY-STATE VOLUME OF DISTRIBUTION FOR A DRUG GIVEN BY INTRAVENOUS-INFUSION

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JOURNAL OF PHARMACOKINETICS AND BIOPHARMACEUTICS 1982年第5期10卷 551-558页

作者： CHAN, KKH GIBALDI, M UNIV WASHINGTON SCH PHARM SEATTLE WA 98195 USA

Although it is generally recognized that estimates of the area under the drug concentration vs. time curve (AUC) after a dose is rather insensitive a curve-fitting procedures, little is known about estimates of mean residues time (MRT) or volume of distribution at steady-state (Vss), both of which can be derived from area estimates. This question is of particular concern when a drug is given as a short-term constant rate i.v. infusion, since the infusion phase is often ignored and blood sampling restricted to the postinfusion period. Two nonexperimental methods for approximating concentration data during infusion, the linear approximation method and the imaginary bolus method, were useful under certain conditions. Both methods provide reasonable estimates of AUC and the area under the 1st moment of the drug concentration-time curve (AUMC) for drugs with a wide range of pharmacokinetic characteristic. The imaginary bolus method was the better of the 2 for estimation of MRT and widely applicable for this purpose. Vss proved to be highly sensitive to the approximation methods;although the imaginary bolus method is superior to the linear approximation method for estimating Vss, it does not work particularly well for drugs with pronounced multicompartment characteristics. Accurate estimation of Vss of drugs given by short-term i.v. infusion requires that at least 1 drug concentration be determined during infusion.

关键词： statistical moments steady-state volume of distribution i.v. infusion linear approximation method imaginary bolus method

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The varieties of intensity correlation time with input signal in a single-mode laser with bias signal modulation

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INTERNATIONAL JOURNAL OF MODERN PHYSICS B 2005年第10期19卷 1801-1813页

作者： Chen, LM Cao, L Wu, DJ Shenzhen Univ Normal Coll Dept Phys Shenzhen 518060 Peoples R China Huazhong Univ Sci & Technol State Key Lab Laser Technol Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol Dept Phys Wuhan 430074 Peoples R China CCAST World Lab Beijing 100080 Peoples R China

The varieties of intensity correlation time T with input signal are studied for gain-noise model of a single-mode laser driven by colored pump noise and colored quantum noise with colored cross-correlation with a bias signal modulation in this paper. By using the linear approximation method, it is found that a minimum (i.e. suppression) in the curves of the intensity correlation time T versus the bias current i(0) exists when the noise correlation coefficient a is negative;and the intensity correlation time T increases monotonously with the increase of i(0) when lambda >= 0. In addition, we also analyze the curve of T versus the signal frequency Omega, find that no matter what the value of A is, a minimum (i.e. suppression) in the T - Omega curves always exists.

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

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Asymptotic Equalities for Best approximations for Classes of Infinitely Differentiable Functions Defined by the Modulus of Continuity

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MATHEMATICAL NOTES 2016年第5-6期99卷 901-915页

作者： Serdyuk, A. S. Sokolenko, I. V. Natl Acad Sci Ukraine Inst Math Kiev Ukraine

We obtain asymptotic estimates for best approximations by trigonometric polynomials in the metric of the space C(L-p) for classes of periodic functions expressible as convolutions of kernels Psi(beta) with Fourier coefficients decreasing to zero faster than any power sequence, and with functions phi is an element of C (phi is an element of L-p) whose moduli of continuity do not exceed the given majorant of omega(t). It is proved that, in the spaces C and L-1, for convex moduli of continuity omega(t), the obtained estimates are asymptotically sharp.

关键词： best approximation by trigonometric polynomials periodic infinitely differentiable function modulus of continuity generalized Poisson kernel linear approximation method Kolmogorov-Nikol'skii problem

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Effect on Intensity Correlation Time by Input Signal in a Single-Mode Laser with Bias Signal Modulation

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Communications in Theoretical Physics 2005年第4X期44卷 638-642页

作者： CHEN Li-Mei CAO Li WU Da-Jin GE Guo-Qin Department of Physics Shenzhen University Shenzhen 518060 China State Key Laboratory of Laser Technology Huazhong University of Science and Technology Wuhan 430074 China Department of Physics Huazhong University of Science and Technology Wuhan 430074 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China

The effect on intensity correlation time T by input signal is studied for gain-noise model of a single-mode laser driven by colored pump noise and colored quantum noise with colored cross-correlation with a bias signal modulation in this paper. By using the linear approximation method, we detect that there exists maximum （i.e., resonance） in the curve of the intensity correlation time T upon bias current io when the noise correlation coefficient λ is positive; and there exists minimum （i.e., suppression） in the T-io curve when λ is negative. And whenλ is zero, T increases monotonously with increasing io. Furthermore, the curve of T upon the signal frequency Ω is also studied. Our study shows that no matter what the value of λ is, there exists minimum （i.e., suppression） in the T-Ω curve.

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

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Improved response surface method based on sample point selection strategies

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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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Solution of interval reactive power optimization model through defining security limits

Solution of interval reactive power optimization model throu...

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International Conference on Power System Technology (POWERCON)

作者： Zhang, Cong Chen, Haoyong Hua, Dong Shi, Ke Liu, Yumeng Wang, Xiaojuan Li, Canbing South China Univ Technol Sch Elect Power Guangzhou 510640 Guangdong Peoples R China Asia Pacific Res Inst Smart Grid & Renewable Ener Hong Kong Peoples R China Hunan Univ Sch Elect & Informat Engn Changsha 410082 Hunan Peoples R China

ISBN: (纸本)9781538664612

The model of reactive power optimization including interval uncertainty (RPOIU) is used to make a voltage control strategy for ensuring the interval state variables (including load voltages and reactive power generation) of the power grid within their safe operating limits, under interval active power generation and power load demand input data. To solve the RPOIU model, this paper defined security limits, and then switches the RPOIU model to two deterministic reactive power optimization models, whose constraints bound limits are the security limits. By solving the deterministic models through the interior point method, a voltage control strategy is obtained as the solution of the RPOIU model. The results obtained by the proposed method are compared with the linear approximation method, which is a previously proposed effective method for solving the RPOIU model, and simulation results and analysis demonstrate the advantages, effectiveness, and good applicability of the proposed method.

关键词： Interval uncertainty reactive power optimization security limits interior point method linear approximation method

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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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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 B 2005年第4期14卷 764-770页

作者：陈黎梅曹力吴大进王忠龙 StateKeyLaboratoryofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China//DepartmentofPhysicsShenzhenUniversityShenzhen518057China DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074China//ChinaCentreofAdvancedScienceandTechnology(WorldLaboratory)Beijing100080China DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074China

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 τ₁. Furthermore, when τ₁≤τ₂, the intensity correlation time T increases monotonically with the increase of D and decreases monotonically with the increase of Q, but when τ₁>τ₂, 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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