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Sensitivity Analysis of Electromagnetic Scattering from Dielectric Targets with Polynomial Chaos Expansion and Method of Moments
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作者 Yujing Ma Zhongwang Wang +2 位作者 Jieyuan Zhang Ruijin Huo Xiaohui Yuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期2079-2102,共24页
In this paper,an adaptive polynomial chaos expansion method(PCE)based on the method of moments(MoM)is proposed to construct surrogate models for electromagnetic scattering and further sensitivity analysis.The MoM is a... In this paper,an adaptive polynomial chaos expansion method(PCE)based on the method of moments(MoM)is proposed to construct surrogate models for electromagnetic scattering and further sensitivity analysis.The MoM is applied to accurately solve the electric field integral equation(EFIE)of electromagnetic scattering from homogeneous dielectric targets.Within the bistatic radar cross section(RCS)as the research object,the adaptive PCE algorithm is devoted to selecting the appropriate order to construct the multivariate surrogate model.The corresponding sensitivity results are given by the further derivative operation,which is compared with those of the finite difference method(FDM).Several examples are provided to demonstrate the effectiveness of the proposed algorithm for sensitivity analysis of electromagnetic scattering from homogeneous dielectric targets. 展开更多
关键词 Adaptive polynomial chaos expansion method method of moments radar cross section electromagnetic scattering
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Measurement of remanent magnetic moment using a torsion pendulum with single frequency modulation method
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作者 乔敏娜 刘鲁华 +4 位作者 蔡柏松 张雅婷 王晴岚 徐家豪 刘祺 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期83-87,共5页
In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic pro... In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic properties. Here we present a single frequency modulation method based on a torsion pendulum to measure the remanent magnetic moment mr of 1.1 kg dummy copper test mass, and the measurement result is(6.45 ± 0.04(stat) ± 0.07(syst)) × 10^(-8)A · m^(2). The measurement precision of the mr is about 0.9 n A · m^(2), well below the present measurement requirement of Tian Qin. The method is particularly useful for measuring extremely low magnetic properties of the materials for use in the construction of space-borne gravitational wave detection and other precision scientific apparatus. 展开更多
关键词 remanent magnetic moment torsion pendulum single frequency modulation method
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An Uncertainty Analysis and Reliability-Based Multidisciplinary Design Optimization Method Using Fourth-Moment Saddlepoint Approximation
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作者 Yongqiang Guo Zhiyuan Lv 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第3期1855-1870,共16页
In uncertainty analysis and reliability-based multidisciplinary design and optimization(RBMDO)of engineering structures,the saddlepoint approximation(SA)method can be utilized to enhance the accuracy and efficiency of... In uncertainty analysis and reliability-based multidisciplinary design and optimization(RBMDO)of engineering structures,the saddlepoint approximation(SA)method can be utilized to enhance the accuracy and efficiency of reliability evaluation.However,the random variables involved in SA should be easy to handle.Additionally,the corresponding saddlepoint equation should not be complicated.Both of them limit the application of SA for engineering problems.The moment method can construct an approximate cumulative distribution function of the performance function based on the first few statistical moments.However,the traditional moment matching method is not very accurate generally.In order to take advantage of the SA method and the moment matching method to enhance the efficiency of design and optimization,a fourth-moment saddlepoint approximation(FMSA)method is introduced into RBMDO.In FMSA,the approximate cumulative generating functions are constructed based on the first four moments of the limit state function.The probability density function and cumulative distribution function are estimated based on this approximate cumulative generating function.Furthermore,the FMSA method is introduced and combined into RBMDO within the framework of sequence optimization and reliability assessment,which is based on the performance measure approach strategy.Two engineering examples are introduced to verify the effectiveness of proposed method. 展开更多
关键词 Reliability-based multidisciplinary design optimization moment method saddlepoint approximate sequence optimization and reliability assessment performance measure approach
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Series expansion feasibility of singular integral in method of moments 被引量:9
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作者 Jinzu Ji Peilin Huang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第3期386-392,共7页
When calculating electromagnetic scattering using method of moments (MoM), integral of the singular term has a significant influence on the results. This paper transforms the singular surface integral to the contour... When calculating electromagnetic scattering using method of moments (MoM), integral of the singular term has a significant influence on the results. This paper transforms the singular surface integral to the contour integral. The integrand is expanded to Taylor series and the integral results in a closed form. The cut-off error is analyzed to show that the series converges fast and only about 2 terms can agree wel with the accurate result. The comparison of the perfect electric conductive (PEC) sphere's bi-static radar cross section (RCS) using MoM and the accurate method validates the feasibility in manipulating the singularity. The error due to the facet size and the cut-off terms of the series are analyzed in examples. 展开更多
关键词 method of moments mom singular term series cut-off error radar cross section (RCS).
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An analysis of the radar backscatter from oil-covered sea surfaces using moment method and Monte-Carlo simulation: preliminary results 被引量:4
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作者 YANG Chan-Su PARK Seong-Min +1 位作者 OH Yisok OUCHI Kazuo 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第1期59-67,共9页
An analysis of the radar backscattering from the ocean surface covered by oil spill is presented using a mi- crowave scattering model and Monte-Carlo simulation. In the analysis, a one-dimensional rough sea sur- face ... An analysis of the radar backscattering from the ocean surface covered by oil spill is presented using a mi- crowave scattering model and Monte-Carlo simulation. In the analysis, a one-dimensional rough sea sur- face is numerically generated with an ocean waveheight spectrum for a given wind velocity. A two-layered medium is then generated by adding a thin oil layer on the simulated rough sea surface. The electric fields backscattered from the sea surface with two-layered medium are computed with the method of moments (MoM), and the backscattering coefficients are statistically obtained with N independent samples for each oil-spilled surface using the Monte-Carlo technique for various conditions of surface roughness, oil-layer thickness, frequency, polarization and incidence angle. The numerical simulation results are compared with theoretical models for clean sea surfaces and SAR images of an off-spilled sea surface caused by the Hebei (Hebei province, China) Spirit oil tanker in 2007. Further, conditions for better oil spill extraction are sought by the numerical simulation on the effects of wind speed and oil-layer thickness at different inci- dence angles on the backscattering coefficients. 展开更多
关键词 method of moments Monte-Carlo technique oil spills backscattering coefficient
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Quadrature Method of Moments for Nanoparticle Coagulation and Diffusion in the Planar Impinging Jet Flow 被引量:5
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作者 于明州 林建忠 熊红兵 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第6期828-836,共9页
A computational model combining large .eddy simulation with quadrature moment method was em-ployed to study nanoparticle evolution in a confined impinging jet. The investigated particle size is limited in the transien... A computational model combining large .eddy simulation with quadrature moment method was em-ployed to study nanoparticle evolution in a confined impinging jet. The investigated particle size is limited in the transient regime, and the particle collision kernel was obtained by using the theory of flux matching. The simulation was validated by comparing it with the experimental results. The numerical results show coherent structure acts to dominate particle number intensity, size and polydispersity distributions, and it also induce particle-laden iet to be diluted by .the ambient.The evolution of particle dynarnics in.the impinging jet flow are strongly related to the Rey-nolds number and nozzle-to-plate distance, and their relationships were analyzed. 展开更多
关键词 NANOPARTICLE COAGULATION impinging jet large eddy simulation quadrature moment method
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Nanoparticle Transport and Coagulation in Bends of Circular Cross Section via a New Moment Method 被引量:4
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作者 林建忠 林培锋 +1 位作者 于明州 陈华军 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第1期1-9,共9页
Transport of nanoparticles and coagulation is simulated with the combination of CFD in a circular bend. The Taylor-expansion moment method(TEMOM)is employed to study dynamics of nanoparticles with Brownian motion,base... Transport of nanoparticles and coagulation is simulated with the combination of CFD in a circular bend. The Taylor-expansion moment method(TEMOM)is employed to study dynamics of nanoparticles with Brownian motion,based on the flow field from numerical simulation.A fully developed flow pattern in the present simulation is compared with previous numerical results for validating the model and computational code.It is found that for the simulated particulate flow system,the particle mass concentration,number concentration,particle polydispersity, mean particle diameter and geometric standard deviation over cross-section increase with time.The distribution of particle mass concentration at different time is independent of the initial particle size.More particles are concen-trated at outer edge of the bend.Coagulation plays more important role at initial stage than that in the subsequent period.The increase of Reynolds number and initial particle size leads to the increase of particle number concentration.The particle polydispersity,mean particle diameter and geometric standard deviation increase with decreasing Reynolds number and initial particle size. 展开更多
关键词 NANOPARTICLE COAGULATION transport flow in bend moment method
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A NEW MOMENT METHOD FOR THE FAST AND ACCURATE ANALYSIS OF NORMAL MODE HELICAL ANTENNAS 被引量:2
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作者 Ji Yicai Sun Baohua Liu Qizhong (Institute of Antennas and EM Scattering, Xidian University, Xi’an 710071) 《Journal of Electronics(China)》 2001年第4期355-358,共4页
In this letter, a new moment method using helical segments is presented to model Normal Mode Helical Antenna (NMHA). Using this method, the NMHA can be modeled by a few segments. The current distributions and radiatio... In this letter, a new moment method using helical segments is presented to model Normal Mode Helical Antenna (NMHA). Using this method, the NMHA can be modeled by a few segments. The current distributions and radiation patterns of some NMHAs are calculated.A comparison is made between results obtained using this helical segment algorithm and a linear segment algorithm, and the results of the two algorithms agree fairly well. When calculating the impedance matrix [Z], all the elements of the matrix can be obtained by only calculating a few elements with the application of the symmetric and periodic characteristics of the NMHA.Therefore, the CPU time and the memory storage are significantly reduced, with the accuracy and speed enhanced. 展开更多
关键词 moment method HELICAL SEGMENT NORMAL MODE HELICAL ANTENNA (NMHA)
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APPLICATION OF THE MOMENT METHODS TO ANALYSIS OF X-RAY DIFFRACTION LINE PROFILE FOR PA1010-BMI SYSTEM 被引量:1
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作者 张宏放 于力 +2 位作者 张利华 莫志深 牟忠诚 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1995年第3期210-217,共8页
Pure X-ray diffraction profiles have been analysed for polyamide 1010 and PA1O1O-BMI system by means of multipeak fitting resolution of X-ray diffraction. The methods of variance and fourth moment have been applied to... Pure X-ray diffraction profiles have been analysed for polyamide 1010 and PA1O1O-BMI system by means of multipeak fitting resolution of X-ray diffraction. The methods of variance and fourth moment have been applied to determine the particle size and strain values for the paracrystalline materials. The results indicated that both variance and fourth moment of X-ray diffraction line profile yielded approximately the same values of the particle size and the strain. The particle sizes of (100) reflection have been found to decrease with increasing BMI content, whereas the strain values increased. 展开更多
关键词 PA1010-BMI SYSTEM CENTRAL moment method WAXD
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Simulation of the Brownian coagulation of nanoparticles with initial bimodal size distribution via moment method 被引量:1
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作者 Jian-Zhong Lin Fu-Jun Gan 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第5期1227-1237,共11页
The Brownian coagulation of nanoparticles with initial bimodal size distribution, i.e., mode i and j, is numerically studied using the moment method. Evolutions of particle number concentration, geometric average diam... The Brownian coagulation of nanoparticles with initial bimodal size distribution, i.e., mode i and j, is numerically studied using the moment method. Evolutions of particle number concentration, geometric average diameter and geometric standard deviation are given in the free molecular regime, the continuum regime, the free molecular regime and transition regime, the free molecular regime and continuum regime, respectively. The results show that, both in the free molecular regime and the continuum regime, the num- ber concentration of mode i and j decreases with increasing time. The evolutions of particle geometric average diameter with different initial size distribution are quite different. Both intra-modal and inter-modal coagulation finally make the polydispersed size distribution become monodispersed. As time goes by, the size distribution with initial bimodal turns to be unimoda/and shifts to a larger particle size range. In the free molecular regime and transition regime, the inter- modal coagulation becomes dominant when the number concentrations of mode i and j are of the same order. The effects of the number concentration of mode i and mode j on the evolution of geometric average diameter of mode j are negligible, while the effects of the number concentration of mode j on the evolution of geometric average diameter of mode j is distinct. In the free molecular regime and continuum regime, the higher the initial number concentration of mode j, the more obvious the variation of the number concentration of mode i. 展开更多
关键词 Nanoparticles - Brownian coagulation. Bimodalsize distribution moment method
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THE CALCULATION METHOD OF FLYWHEEL MOMENT OFINERTIA OF CRANE MECHANISM
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作者 谷永茂 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1995年第4期64-67,共4页
The origin and substance of the tlywheel moment calculation method of inertia mo ment of crane mechanism are set forth comprehensively and systematically in this paper, that is, the nucleus or the focus ofmoment of in... The origin and substance of the tlywheel moment calculation method of inertia mo ment of crane mechanism are set forth comprehensively and systematically in this paper, that is, the nucleus or the focus ofmoment of inertia calculation is the problem of calculating convertible tlywheelmoment. It is much better for the calculation of flywheel moment of loading move mass of lifting, traveling and rotating mechanism using the low of conservation of energy, the theorem of kinetic energyfor that of radius - changing mechanism, and the law of conservation of energy for that of all parts of gearing mechanism. 展开更多
关键词 MECHANISM of CRANE moment of INERTIA moment of FLYWHEEL CALCULATION method
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The New Application of Multilevel Method of Moments in Analysis of Wire-Antenna Arrays
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作者 Jin Qi, Guan Rongsheng, Xie Shuguo(College of Electronic Information, Wuhan University, Wuhan 430072, China) 《Wuhan University Journal of Natural Sciences》 CAS 1998年第1期46-48,共3页
This paper introduces the principle of the multi-level method of moments (MoM) and its application in the analysis of the wire-antenna arrays. The multi-level MoM broadens the usage of the iterative methods in the MoM... This paper introduces the principle of the multi-level method of moments (MoM) and its application in the analysis of the wire-antenna arrays. The multi-level MoM broadens the usage of the iterative methods in the MoM. Our numerical results show that when applying it to the wire-antenna array analysis with the consideration of the mutual coupling between elements, it can allow a rapid and accurate evaluation of the current distribution on the antennas, and the computational cost is less, especially when the number of antennas is large. 展开更多
关键词 multilevel mom wire antenna iterative method CONVERGENCE
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The moment-method form of Pocklington's integral equation above ground
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作者 江滨浩 刘永坦 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第3期14-18,共5页
Pocklington’s integral equation is presented for analysis of current distributions on wire antenna above ground. Sommerfeld type integrals, the kernel functions of the integral equation, can be approximately expresse... Pocklington’s integral equation is presented for analysis of current distributions on wire antenna above ground. Sommerfeld type integrals, the kernel functions of the integral equation, can be approximately expressed as the elementary functions using the Fresnel plane wave reflection coefficients method; and the Pocklington’s integral equation will be rearranged into a linear equation with solution easily obtained by using the method of moments, when the sinusoidal sub domain expansion is chosen to express the current distributions. 展开更多
关键词 electromagnetic theory Pocklington’s INTEGRAL EQUATION method of momentS sommerfeld type INTEGRALS
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A method of moments for calculating dynamic responses beyond linear response theory
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作者 康艳梅 徐健学 谢勇 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第9期1691-1697,共7页
A method of moments for calculating the dynamic response of periodically driven overdamped nonlinear stochastic systems in the general response sense is proposed, which is a modification of the method of moments confi... A method of moments for calculating the dynamic response of periodically driven overdamped nonlinear stochastic systems in the general response sense is proposed, which is a modification of the method of moments confined within linear response theory. The calculating experience suggests that the proposed technique is simple and efficient in implementation, and the comparison with stochastic simulation shows that the first three orders of susceptibilities calculated by the proposed technique have high accuracy. The dependence of the spectral amplification parameters at the first three harmonics on the noise intensity is also investigated, and another observed phenomenon of stochastic resonance in the systems induced by the location of a single periodic orbit is disclosed and explained. 展开更多
关键词 a method of moments dynamic susceptibility spectral amplification factor stochastic resonance
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Fourier Moment Method with Regularization for the Cauchy Problem of Helmholtz Equation
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作者 MA YUN-YUN MA FU-MING 《Communications in Mathematical Research》 CSCD 2012年第4期300-312,共13页
In this paper, we consider the reconstruction of the wave field in a bounded domain. By choosing a special family of functions, the Cauchy problem can be transformed into a Fourier moment problem. This problem is ill-... In this paper, we consider the reconstruction of the wave field in a bounded domain. By choosing a special family of functions, the Cauchy problem can be transformed into a Fourier moment problem. This problem is ill-posed. We propose a regularization method for obtaining an approximate solution to the wave field on the unspecified boundary. We also give the convergence analysis and error estimate of the numerical algorithm. Finally, we present some numerical examples to show the effectiveness of this method. 展开更多
关键词 Fourier moment method Cauchy problem Helmholtz equation regu-larization ill-possedness
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METHOD OF MOMENT EXCITATION IN TESTING OF STRUCTURES
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作者 B.M.Gibbs 《Acta Mechanica Solida Sinica》 SCIE EI 1995年第3期277-282,共6页
The method of the moment excitation in the studies of the structure-borne sound using a moment actuator is introduced. Some design considerations for the moment actuator are presented. A standard mechanical system is ... The method of the moment excitation in the studies of the structure-borne sound using a moment actuator is introduced. Some design considerations for the moment actuator are presented. A standard mechanical system is established to calibrate the performance of the moment actuator. The frequency and mechanical power performances of the actuator are discussed. 展开更多
关键词 moment ACTUATOR ANALOGOUS CIRCUIT CROSS-SPECTRUM method
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A Method of Moment Approach in Solving Boundary Value Problems
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作者 Hilal M. El Misilmani Karim Y. Kabalan +1 位作者 Mohamad Y. Abou-Shahine Mohammed Al-Husseini 《Journal of Electromagnetic Analysis and Applications》 2015年第3期61-65,共5页
Several available methods, known in literatures, are available for solving nth order differential equations and their complexities differ based on the accuracy of the solution. A successful method, known to researcher... Several available methods, known in literatures, are available for solving nth order differential equations and their complexities differ based on the accuracy of the solution. A successful method, known to researcher in the area of computational electromagnetic and called the Method of Moment (MoM) is found to have its way in this domain and can be used in solving boundary value problems where differential equations are resulting. A simplified version of this method is adopted in this paper to address this problem, and two differential equations examples are considered to clarify the approach and present the simplicity of the method. As illustrated in this paper, this approach can be introduced along with other methods, and can be considered as an attractive way to solve differential equations and other boundary value problems. 展开更多
关键词 Boundary Value Problem Differential EQUATIONS method of moment GALERKIN method WEIGHT Coefficient
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Monte Carlo Integration Technique for Method of Moments Solution of EFIE in Scattering Problems
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作者 Mrinal MISHRA Nisha GUPTA 《Journal of Electromagnetic Analysis and Applications》 2009年第4期254-258,共5页
An integration technique based on use of Monte Carlo Integration is proposed for Method of Moments solution of Electric Field Integral Equation. As an example numerical analysis is carried out for the solution of the ... An integration technique based on use of Monte Carlo Integration is proposed for Method of Moments solution of Electric Field Integral Equation. As an example numerical analysis is carried out for the solution of the integral equation for unknown current distribution on metallic plate structures. The entire domain polynomial basis functions are employed in the MOM formulation which leads to only small number of matrix elements thus saving significant computer time and storage. It is observed that the proposed method not only provides solution of the unknown current distribution on the surface of the metallic plates but is also capable of dealing with the problem of singularity efficiently. 展开更多
关键词 SCATTERING EFIE method of momentS MONTE Carlo INTEGRATION
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Computation of Protection Zone of a Lightning Rod Using Method of Moments and Monte Carlo Integration Technique
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作者 Abhay Srivastava Ankhuri Dubey +1 位作者 Shradha Shekhar Mrinal Mishra 《Journal of Electromagnetic Analysis and Applications》 2011年第4期118-121,共4页
An accurate determination of lightning protection zone is an important issue in the analysis and design of an appropri-ate lightning protection system. This paper presents a fast and accurate protection zone determina... An accurate determination of lightning protection zone is an important issue in the analysis and design of an appropri-ate lightning protection system. This paper presents a fast and accurate protection zone determination methodology for metallic lightning rod. The methodology is based on Quasi Monte Carlo Integration technique applied to Method of Moments (MoM) solution of Integral Equations. As an example, solution of the integral equation for unknown charge distribution on lightning rod is obtained. The electric field in the region surrounding the rod is then computed and the protection zone plotted accordingly. The effect of the thickness of the rod on the protection zone is also studied. 展开更多
关键词 LIGHTNING ROD QUASI MONTE Carlo Integration method of momentS Protection Zone
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Investigation of Thermodynamic Properties of Zirconia Thin Films by Statistical Moment Method
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作者 Vu Van Hung Le Thi Thanh Huong Dang Thanh Hai 《Materials Sciences and Applications》 2018年第12期949-964,共16页
The moment method in statistical (SMM) dynamics is used to study the thermodynamic quantities of ZrO2 thin films taking into account the anharmonicity effects of the lattice vibrations. The average lattice constant, t... The moment method in statistical (SMM) dynamics is used to study the thermodynamic quantities of ZrO2 thin films taking into account the anharmonicity effects of the lattice vibrations. The average lattice constant, thermal expansion coefficient and specific heats at the constant volume of ZrO2 thin films are calculated as a function of temperature, pressure and thickness of thin film. SMM calculations are performed using the Buckingham potential for the ZrO2 thin films. In the present study, the influence of temperature, pressure and the size on the thermodynamic quantities of ZrO2 thin film have been studied using three different interatomic potentials. We discuss temperature and thickness dependences of some thermodynamic quantities of ZrO2 thin films and we compare our calculated results with those of the experimental results. 展开更多
关键词 Thin Film ZIRCONIA Lattice CONSTANT Thermal Expansion Coefficient Specific HEATS at the CONSTANT Volume STATISTICAL moment method
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