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Research on monopulse forward-looking high-resolution imaging algorithm based on adaptive iteration

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Defence Technology（防务技术） 2020年第1期16卷 158-171页

作者： Cheng Cheng Xiao-dong Zhou Min Gao Zhu-lin Zong Yong-xiang Ji Bo Yu Department of Missile Engineering Army Engineering UniversityNo.97 Westroad HepingShijiazhuangChina Department of Ammunition Engineering Army Engineering UniversityNo.97 Westroad HepingShijiazhuangChina Research Institute of Electronic Science and Technology University of Electronic Science and TechnologyNo.4Section 2Jianbei RoadChengduChina China Huayin Weapon Test Center No.450 Yuemiao StreetHuayinShaanxiChina North Automatic Control Technology Institute No.351 Tiyu RoadTaiyuanChina

In this paper,we proposed a monopulse forward-looking high-resolution imaging algorithm based on adaptive iteration for missile-borne *** iteration,the proposed algorithm automatically selects the echo signal of isolated strong-scattering points from the receiving echo signal data to accurately estimate the actual optimal monopulse response curve(MRC) of the same distance range,and we applied optimal MRC to realize the azimuth self-focusing in the process of *** use real-time echo data to perform error correction for obtaining the optimal MRC,and the azimuth angulation accuracy may reach the optimum at a certain distance *** experimentally demonstrate the validity,reliability and high performance of the proposed *** azimuth angulation accuracy may reach up to ten times of the detection *** simulation experiments have verified the feasibility of this strategy,with the average height measurement error being 7.8%.In the out-field unmanned aerial vehicle(UAV) tests,the height measurement error is less than 25 m,and the whole response time can satisfy the requirements of a missile-borne detector.

关键词： Monopulse imaging High-resolution Adaptive iteration Missile-borne detector

A Unification of the Concepts of the Variational iteration, Adomian Decomposition and Picard iteration Methods;and a Local Variational iteration Method

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Computer Modeling in Engineering & Sciences 2016年第6期111卷 567-585页

作者： Xuechuan Wang Satya N.Atluri Texas Tech University Center for Advanced Research in the Engineering Sciences Northwestern Polytechnical University China

This paper compares the variational iteration method(VIM),the Adomian decomposition method(ADM)and the Picard iteration method(PIM)for solving a system of first o rder n onlinear o rdinary d ifferential e quations(ODEs).A unification of the concepts underlying these three methods is attempted by considering a very general iterative algorithm for *** is found that all the three methods can be regarded as special cases of using a very general matrix of Lagrange multipliers in the iterative algorithm of *** global variational iteration method is briefly reviewed,and further recast into a Local VIM,which is much more convenient and capable of predicting long term complex dynamic responses of nonlinear systems even if they are chaotic.

关键词： Variational iteration method Adomian decomposition method Picard iteration method asymptotic technique nonlinear dynamical system

Low-Complexity Signal Detection Based on Relaxation iteration Method in Massive MIMO Systems

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China Communications 2015年第S1期12卷 1-8页

作者： GUO Ruohan LI Xiaohui FU Weihong HEI Yongqiang State Key Laboratory of Integrated Service Networks Xidian University

Minimum mean square error(MMSE) detection algorithm can achieve nearly optimal performance when the number of antennas at the base station(BS) is large enough compared to the number of users. But the traditional MMSE involves complicated matrix inversion. In this paper, we propose a modified MMSE algorithm which exploits the channel characteristics occurring in massive multiple-input multipleoutput(MIMO) channels and the relaxation iteration(RI) method to avoid the matrix inversion. A proper initial solution is given to accelerate the convergence speed. In addition, we point out that the channel estimation scheme used in channel hardening-exploiting message passing(CHEMP) receiver is very appropriate for our proposed detection algorithm. Simulation results verify that the proposed algorithm can achieve very close performance of the traditional MMSE algorithm with a small number of iterations.

关键词： massive MIMO detection minimum mean square error relaxation iteration channel estimation

Convergence of the iteration of Halley's family and Smale operator class in Banach space

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Science China Mathematics 1998年第7期41卷 700-709页

作者：王兴华 1. Department of Mathematics Hangzhou University 310028 Hangzhou China

Smale operator classes of any order for nonlinear operators in Banach space are introduced. For an operatorf in Smale operator class of orderk, a proper condition for the convergence and the exact estimations error for the iteration of Halley’s family {H j,k n } n=0 ∞ (1≤j≤k) are given. This Halley’s family is a higher order explicit generalization of Newton iteration.

关键词： Smale operator class iteration of Halley’s family convergence dynamics on Riemann sphere.

A distributed inverse iteration method for eigenvalue analysis of interconnected power systems

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Science China(Technological Sciences) 2007年第6期50卷 774-785页

作者： SHEN Chen CHEN Ying ZHANG Xu State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China

Since China power grids have a hierarchical architecture in operation and man- agement, centralized computation patterns are difficult to meet the demands of small-signal-stability analysis of the bulk interconnected power systems. A dis- tributed eigenvalue algorithm derived from the inverse iteration method is pro- posed. It can not only obtain eigenvalues and eigenvectors from power system state matrix but also provide participation factors of all generators. In the comput- ing process, the algorithm only requires exchanging data of boundary nodes and a small amount of other information of different regions. Therefore, it is very suitable to be deployed in a WAN (wide area network) based distributed environment. The algorithm has been tested on an IEEE39 system.

关键词： distributed computing, eigenvalue, small signal stability, inverse iteration method

Some geometrical iteration methods for nonlinear equations

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Applied Mathematics(A Journal of Chinese Universities) 2008年第1期23卷 25-30页

作者： LU Xing-jiang QIAN Chun Dept. of Math Zhejiang Univ. Hangzhou 310027 China. College of Statist. and Comput. Sci. Zhejiang Gongshang Univ. Hangzhou 310018China.

This paper describes geometrical essentials of some iteration methods （e.g. Newton iteration, secant line method, etc.） for solving nonlinear equations and advances some geometrical methods of iteration that are fle... 详细信息

关键词： nonlinear equation iteration geometric method.

Efficient Orbit Propagation of Orbital Elements Using Modified Chebyshev Picard iteration Method

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Computer Modeling in Engineering & Sciences 2016年第1期111卷 65-81页

作者： J.L.Read A.Bani Younes J.L.Junkins Graduate Research Assistant Texas A&M UniversityCollege StationTXUSA. Assistant Professor Khalifa UniversityAbu DhabiUAE. Distinguished Professor Texas A&M UniversityCollege StationTXUSA.

This paper focuses on propagating perturbed two-body motion using orbital elements combined with a novel integration *** previous studies show that Modified Chebyshev Picard iteration(MCPI)is a powerful tool used to propagate position and velocity,the present results show that using orbital elements to propagate the state vector reduces the number of MCPI iterations and nodes required,which is especially useful for reducing the computation time when including computationally-intensive calculations such as Spherical Harmonic gravity,and it also converges for>5.5x as many revolutions using a single segment when compared with cartesian *** for the Classical Orbital Elements and the Modified Equinoctial Orbital Elements(the latter provides singularity-free solutions)show that state propagation using these variables is inherently well-suited to the propagation method *** benefits are achieved using a segmentation scheme,while future expansion to the two-point boundary value problem is expected to increase the domain of convergence compared with the cartesian *** is an iterative numerical method used to solve linear and nonlinear,ordinary differential equations(ODEs).It is a fusion of orthogonal Chebyshev function approximation with Picard iteration that approximates a long-arc trajectory at every *** studies have shown that it outperforms the state of the practice numerical integrators of ODEs in a serial computing environment;since MCPI is inherently massively parallelizable,this capability is expected to increase the computational efficiency of the method presented.

关键词： Propagation Integration Orbital Mechanics Classical Elements Modified Equinoctial Chebyshev Picard iteration MCPI Polynomials Initial Value Problem IVP.

On Minimization of Upper Bound for the Convergence Rate of the QHSS iteration Method

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Communications on Applied Mathematics and Computation 2019年第2期1卷 263-282页

作者： Wen-Ting Wu State Key Laboratory of Scientific/Engineering Computing Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of Sciences. P.O. Box 2719. Beijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

For an upper bound of the spectral radius of the QHSS (quasi Hermitian and skew-Hermitian splitting) iteration matrix which can also bound the contraction factor of the QHSS iteration method,we give its minimum point under the conditions which guarantee that the upper bound is strictly less than one. This provides a good choice of the involved iteration parameters,so that the convergence rate of the QHSS iteration method can be significantly improved.

关键词： System of linear equations Non-Hermitian matrix QHSS iteration method Convergence rate

AN EFFICIENT iteration ALGORITHM OF MIXED BOUNDARY/FINITE ELEMENT METHOD AND APPLICATION TO FREE TORSIONAL VIBRATION ANALYSIS OF BODIES OF REVOLUTION

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Applied Mathematics and Mechanics(English Edition) 1990年第12期11卷 1187-1194页

作者：王秀喜陈锋钱江 1. University of Science and Technology of China Hefei

In this paper, the general formulation of anew proposed iteration algorithm of mixed BEM/FEM for eigenvalue problems of elastodynamics is described. Approximate fundamental solutions of elastodynamics are adopted in the normal mixed BEM/FEM equations. The accuracy of solutions is progressively improved by the iteration procedure. Not only could the awkwardness of non-algebraic eigenvalue equations be avoided but also the accuracy of numerical solutions is almost independent of the interior meshing. All these give many advantages in numerical calculation. The algorithm is applied to free torsional vibration analysis of bodies of revolution. A few cases are studied. All of the numerical results are very good.

关键词： mixed BEM/FEM formulation iteration free vibration bodies of revolution