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基于有理非线性函数的Fast-ICA算法 被引量:3
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作者 何安玲 何选森 《计算机工程与应用》 CSCD 北大核心 2018年第1期251-255,270,共6页
利用Fast-ICA算法进行超高斯信源盲分离时,计算其目标函数所选取的非线性函数主要是双曲正切函数(tanh)和高斯函数(gauss)。由于tanh和gauss函数的计算负担较大,从而增加了分离混合信号的运行时间。为了提高Fast-ICA算法的收敛速度,提... 利用Fast-ICA算法进行超高斯信源盲分离时,计算其目标函数所选取的非线性函数主要是双曲正切函数(tanh)和高斯函数(gauss)。由于tanh和gauss函数的计算负担较大,从而增加了分离混合信号的运行时间。为了提高Fast-ICA算法的收敛速度,提出两个有理非线性函数用于代替tanh和gauss,使得改进的Fast-ICA算法在提高计算速度的同时保持或提高信号的分离性能。仿真实验验证了改进算法的有效性。 展开更多
关键词 盲源分离(BSS) 独立分量分析(ICA) 快速独立分量分析(Fast-ICA) 有理非线性函数 切比雪夫-帕德逼近
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采用Pade逼近的有理非线性Fast-ICA 被引量:1
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作者 何选森 徐丽 《重庆邮电大学学报(自然科学版)》 CSCD 北大核心 2022年第2期258-268,共11页
针对快速独立分量分析(fast independent component analysis, Fast-ICA)算法中非线性(nonlinearity)本身的计算负担会造成算法收敛速度下降的问题,提出一种有理多项式函数替代经典非线性的方法。通过将传统的非线性进行泰勒级数展开,利... 针对快速独立分量分析(fast independent component analysis, Fast-ICA)算法中非线性(nonlinearity)本身的计算负担会造成算法收敛速度下降的问题,提出一种有理多项式函数替代经典非线性的方法。通过将传统的非线性进行泰勒级数展开,利用Pade逼近技术推导出相应的有理多项式函数。有理函数的分子采用一次多项式,而分母采用二次多项式,在保证有理函数为真分式的同时还简化了其计算。仿真结果表明,采用有理非线性的Fast-ICA算法不仅能够提高算法的收敛速度,而且还能提高算法的盲源分离(blind source separation, BSS)性能。 展开更多
关键词 盲源分离(BSS) 独立分量分析(ICA) 快速独立分量分析 PADE逼近 泰勒级数展开 有理非线性
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遥感图像几何校正的非线性有理逼近模型 被引量:8
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作者 张连蓬 陶华学 +1 位作者 刘国林 江涛 《煤炭学报》 EI CAS CSCD 北大核心 2003年第2期140-144,共5页
遥感图像几何校正是遥感图像处理与分析中的一个重要环节,常用的校正模型有仿射变换和代数多项式.由于引起图像几何变形的原因非常复杂,从而使变形呈现非常复杂的非线性现象,传统的校正方法常常无法得到很好的校正结果.有理多项式有更... 遥感图像几何校正是遥感图像处理与分析中的一个重要环节,常用的校正模型有仿射变换和代数多项式.由于引起图像几何变形的原因非常复杂,从而使变形呈现非常复杂的非线性现象,传统的校正方法常常无法得到很好的校正结果.有理多项式有更强的非线性特性,能更准确地描述图像的非线性变形.提出了一个有理多项式校正模型并给出了一套快速的参数估计方法,实例验证表明,有理多项式模型更精确地逼近了非线性变形,提高了几何校正的精度. 展开更多
关键词 遥感图像 几何校正 非线性有理逼近 图像处理 参数估计
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基于Mastercam平台等距曲面的开发研究
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作者 余贵珍 丁能根 王素 《机械设计与制造》 北大核心 2007年第12期89-91,共3页
介绍Mastercam V9平台下C-Hook开发环境,讨论等距曲面的基本算法,解决相连多曲面的等距曲面的问题,给出等距曲面的误差控制方法,在Mastercam V9平台下实现等距曲面的开发。
关键词 MASTERCAM 非线性有理B样条 等距曲面
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New Exact Solutions for Konopelchenko-Dubrovsky Equation Using an Extended Riccati Equation Rational Expansion Method 被引量:5
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作者 SONG Li-Na ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5期I0003-I0003,770-776,共8页
Taking the Konopelchenko-Dubrovsky system as a simple example, some familles of rational formal hyperbolic function solutions, rational formal triangular periodic solutions, and rational solutions are constructed by u... Taking the Konopelchenko-Dubrovsky system as a simple example, some familles of rational formal hyperbolic function solutions, rational formal triangular periodic solutions, and rational solutions are constructed by using the extended Riccati equation rational expansion method presented by us. The method can also be applied to solve more nonlinear partial differential equation or equations. 展开更多
关键词 Konopelchenko-Dubrovsky equation extended Riccati equation rational expansion method nonlinear partial differential equation or equations
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A Coupled Analysis of Nonlinear Sloshing and Ship Motion 被引量:4
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作者 Shuo Huang Wenyang Duan Hao Zhang 《Journal of Marine Science and Application》 2012年第4期427-436,共10页
Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non... Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non-Uniform Rational B-Spline (NURBS) higher-order panel method in time domain based on the potential theory. A robust and stable improved iterative procedure (Yan and Ma, 2007) for floating bodies is used for calculating the time derivative of velocity potential and floating body motion. An energy dissipation condition based on linear theory adopted by Huang (2011) is developed to consider flow viscosity effects of sloshing flow in nonlinear model. A two-dimensional tank model test was performed to identify its validity. The present nonlinear coupling sway motion results are subsequently compared with the corresponding Rognebakke and Faltinsen (2003)'s experimental results, showing fair agreement. Thus, the numerical approach presented in this paper is expected to be very efficient and realistic in evaluating the coupling effects of nonlinear sloshing and body motion. 展开更多
关键词 NONLINEAR tank-sloshing coupling motion energy dissipation
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Extended Riccati Equation Rational Expansion Method and Its Application to Nonlinear Stochastic Evolution Equations 被引量:2
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作者 WANG Mei-Jiao WANG Qi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5期785-789,共5页
In this work, by means of a new more general ansatz and the symbolic computation system Maple, we extend the Riccati equation rational expansion method [Chaos, Solitons & Fractals 25 (2005) 1019] to uniformly const... In this work, by means of a new more general ansatz and the symbolic computation system Maple, we extend the Riccati equation rational expansion method [Chaos, Solitons & Fractals 25 (2005) 1019] to uniformly construct a series of stochastic nontravelling wave solutions for nonlinear stochastic evolution equation. To illustrate the effectiveness of our method, we take the stochastic mKdV equation as an example, and successfully construct some new and more general solutions including a series of rational formal nontraveling wave and coefficient functions' soliton-like solution.s and trigonometric-like function solutions. The method can also be applied to solve other nonlinear stochastic evolution equation or equations. 展开更多
关键词 extended Riccati equation rational expansion method nonlinear stochastic evolution equation stochastic mKdV equation soliton-like solutions
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Stability analysis of a concrete gravity dam and its foundation
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作者 Itoya Emioshor 赵引 Martins Y.Otache 《Journal of Southeast University(English Edition)》 EI CAS 2004年第4期508-512,共5页
The stability of dams and their foundations is an important problem to which dam engineers have paid close attention over the years. This paper presented two methods to analyze the stability of a gravity dam and its f... The stability of dams and their foundations is an important problem to which dam engineers have paid close attention over the years. This paper presented two methods to analyze the stability of a gravity dam and its foundation. The direct analysis method was based on a rigid limit equilibrium method which regarded both dam and the rock foundation as undeformable rigid bodies. In this method, the safety factor of potential sliding surfaces was computed directly. The second method, the indirect analysis method, was based on elasto-plastic theory and employs nonlinear finite element method (FEM) in the analysis of stresses and deformation in the dam and its foundation. The determination of the safety degree of the structure was based on the convergence and abrupt the change criterion. The results obtained showed that structures' constituent material behavior played an active role in the failure of engineered structures in addition to the imposed load. 展开更多
关键词 Concrete dams Elastoplasticity Finite element method Nonlinear equations Safety factor Sensitivity analysis Shear strength
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Influence of wave and current on deep-sea mining transporting system 被引量:3
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作者 XU Hai-liang ZHOU Gang +1 位作者 WU Bo WU Wan-rong 《Journal of Central South University》 SCIE EI CAS 2012年第1期144-149,共6页
As a solution to the breaking of pipeline under high axial force,carbon fiber composite pipe with low density and high intensity is applied to deep-sea mining transporting system.Based on the fact that the transportin... As a solution to the breaking of pipeline under high axial force,carbon fiber composite pipe with low density and high intensity is applied to deep-sea mining transporting system.Based on the fact that the transporting pipe is under the forces of gravity,inner liquid,buoyancy as well as hydrodynamic force,geometric nonlinear finite element theory has been applied to analyzing the transporting system.Conclusions can be drawn as follows.Under the interaction of waves and currents,node forces FX and FZ acted by the transporting pipe on the mining vehicle are less than 2 kN,which indicates that waves and currents have little influence on the spatial shape of the transporting pipe and the mining vehicle movement.On the other hand,the horizontal force acting on the mining ship could be as large as 106 830 N,which has great influence on the mining system. 展开更多
关键词 carbon fiber composite pipe waves and ocean currents finite element mineral transporting system mechanical analysis
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Rational Solutions for the Discrete Painlevé Ⅱ Equation
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作者 赵玲玲 商朋见 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第3期24-29, ,共6页
The rational solutions for the discrete Painlevé Ⅱ equation are constructed based on the bilinear formalism. It is shown that they are expressed by a determinant whose entries are given by the Laguerre Polynomials.
关键词 Painlevé equation discrete Painlevé equation rational solution
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New Families of Nontravelling Wave Solutions to Two (3+1)-Dimensional Equations
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作者 BAICheng-Lin LIUXi-Qiang ZHAOHong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3期417-422,共6页
In this paper, two (3+1)-dimensional equations are investigated.Auto-Baecklund transformation is obtained, which is used with some ansatze to seek new types ofexact solutions including some arbitrary functions. When t... In this paper, two (3+1)-dimensional equations are investigated.Auto-Baecklund transformation is obtained, which is used with some ansatze to seek new types ofexact solutions including some arbitrary functions. When these arbitrary functions are taken assome special functions, these solutions possess abundant structures. These solutions containsoliton-like solutions and rational solutions. 展开更多
关键词 (3+1)-dimensional equations soliton-like solutions rational solutions
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A New Generalized Riccati Equation Rational Expansion Method to Generalized Burgers-Fisher Equation with Nonlinear Terms of Any Order 被引量:1
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作者 ZHANG Xiao-Ling WANG Jing ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5X期779-786,共8页
In this paper, based on a new more general ansitz, a new algebraic method, named generalized Riccati equation rational expansion method, is devised for constructing travelling wave solutions for nonlinear evolution eq... In this paper, based on a new more general ansitz, a new algebraic method, named generalized Riccati equation rational expansion method, is devised for constructing travelling wave solutions for nonlinear evolution equations with nonlinear terms of any order. Compared with most existing tanh methods for finding travelling wave solutions, the proposed method not only recovers the results by most known algebraic methods, but also provides new and more general solutions. We choose the generalized Burgers-Fisher equation with nonlinear terms of any order to illustrate our method. As a result, we obtain several new kinds of exact solutions for the equation. This approach can also be applied to other nonlinear evolution equations with nonlinear terms of any order. 展开更多
关键词 generalized Riccati equation rational expansion method generalized Burgers-Fisher equation with nonlinear terms of any order symbolic computation
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New Rational Form Solutions to Coupled Nonlinear Wave Equations
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作者 FU Zun-Tao LIN Guang-Xing +1 位作者 LIU Shi-Kuo LIU Shi-Da 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2X期235-242,共8页
The new rational form solutions to the elliptic equation are shown, and then these solutions to the elliptic equation are taken as a transformation and applied to solve nonlinear coupled wave equations. It is shown th... The new rational form solutions to the elliptic equation are shown, and then these solutions to the elliptic equation are taken as a transformation and applied to solve nonlinear coupled wave equations. It is shown that more novel kinds of solutions are derived, such as periodic solutions of rational form, solitary wave solutions of rational form,and so on. 展开更多
关键词 elliptic equation Jacobi elliptic function nonlinear coupled equations periodic wave solution rational form
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Further Extended Jacobi Elliptic Function Rational Expansion Method and New Families of Jacobi Elliptic Function Solutions to (2+1)-Dimensional Dispersive Long Wave Equation
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作者 ZHANG Yuan-Yuan WANG Qi ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第2期199-206,共8页
In this paper, a further extended Jacobi elliptic function rationM expansion method is proposed for constructing new forms of exact solutions to nonlinear partial differential equations by making a more general transf... In this paper, a further extended Jacobi elliptic function rationM expansion method is proposed for constructing new forms of exact solutions to nonlinear partial differential equations by making a more general transformation. For illustration, we apply the method to (2+1)-dimensionM dispersive long wave equation and successfully obtain many new doubly periodic solutions. When the modulus m→1, these sohitions degenerate as soliton solutions. The method can be also applied to other nonlinear partial differential equations. 展开更多
关键词 doubly periodic solution soliton solution (2+1)-dimensional dispersive long wave equation
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Traveling Wave Solutions for Nonlinear Differential-Difference Equations of Rational Types 被引量:2
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作者 smail Aslan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第1期39-45,共7页
Differential-difference equations are considered to be hybrid systems because the spatial variable n is discrete while the time t is usually kept continuous.Although a considerable amount of research has been carried ... Differential-difference equations are considered to be hybrid systems because the spatial variable n is discrete while the time t is usually kept continuous.Although a considerable amount of research has been carried out in the field of nonlinear differential-difference equations,the majority of the results deal with polynomial types.Limited research has been reported regarding such equations of rational type.In this paper we present an adaptation of the(G /G)-expansion method to solve nonlinear rational differential-difference equations.The procedure is demonstrated using two distinct equations.Our approach allows one to construct three types of exact traveling wave solutions(hyperbolic,trigonometric,and rational) by means of the simplified form of the auxiliary equation method with reduced parameters.Our analysis leads to analytic solutions in terms of topological solitons and singular periodic functions as well. 展开更多
关键词 differential-difference equations (G′/G)-expansion method exact solutions traveling wave solu-tions
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6-CANONICAL MAPS OFNONSINGULAR MINIMAL 3-FOLDS
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作者 CHEN MENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1995年第2期163-170,共8页
The aim of this paper is to study 6-canonical system of a nonsingular minimal 3-fold X. If|2Kx|is not composed of pencils, it is shown that is birational with possible exceptionsfor:
关键词 Canonical map Nonsingular minimal 3-fold Birational map.1991 MR Subject Classification 14E05 14J30.
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Failure mechanism of full-size concrete filled steel circle and square tubes under uniaxial compression 被引量:2
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作者 CAI JingMing PAN JinLong SHAN QiFeng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第10期1638-1647,共10页
In this paper, the failure mechanisms of full-size concrete filled steel tubes(CFST) under uniaxial compression were investigated with nonlinear finite element method. Existing experimental results were employed to ve... In this paper, the failure mechanisms of full-size concrete filled steel tubes(CFST) under uniaxial compression were investigated with nonlinear finite element method. Existing experimental results were employed to verify the validity of the finite element models of CFST specimens. Then, the numerical analysis was further conducted to study the mechanical behaviors of full-size CFST columns with circular and square cross sections under uniaxial compression. The simulation results indicate that the distribution of the contact pressure between circular steel tube and core concrete is much more uniform than that between square steel tube and concrete, resulting in much higher confinement and more efficient interaction between steel tube and core concrete in circular CFST columns, as well as ultimate load capacity and ultimate displacement. Extensive parametric analysis was also conducted to examine the effect of various parameters on the uniaxial compression behaviors of circular and square CFST columns. 展开更多
关键词 CFST uniaxial compression finite element analysis interaction mechanism
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A Result on the Quasi-periodic Solutions of Forced Isochronous Oscillators at Resonance
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作者 Bin LIU Yingchao TANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第4期523-542,共20页
In this paper, the authors are concerned with the forced isochronous oscillators with a repulsive singularity and a bounded nonlinearity x'' + V'(x) + g(x) = e(t, x, x'),where the assumptions on V, g a... In this paper, the authors are concerned with the forced isochronous oscillators with a repulsive singularity and a bounded nonlinearity x'' + V'(x) + g(x) = e(t, x, x'),where the assumptions on V, g and e are regular, described precisely in the introduction.Using a variant of Moser's twist theorem of invariant curves, the authors show the existence of quasi-periodic solutions and boundedness of all solutions. This extends the result of Liu to the case of the above system where e depends on the velocity. 展开更多
关键词 Isochronous oscillators Repulsive singularity Invariant curves Timereversibility Quasi-periodic solutions Lazer-Landesman conditions Boundedness of solutions
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The instability of an elastic planet with a liquid core
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作者 Shengjun Fan Yanju Liu Fei Jia 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第12期101-110,共10页
Considering a spherical planet with a liquid core surrounded by a solid shell,we developed a quasi-static model to investigate the deformation of the double-layered planet with self-gravity and obtained the boundary v... Considering a spherical planet with a liquid core surrounded by a solid shell,we developed a quasi-static model to investigate the deformation of the double-layered planet with self-gravity and obtained the boundary value problem about radial equilibrium,which is solved by the numerical methods.The effects of governing parameters about geometry,density and bulk modulus on the deformation of the planet with self-gravity were discussed.In addition,we also developed the incremental equation theory to investigate the stability of the double-layered planet under its own gravity.It is concluded that instability is more likely to occur on the planet with smaller liquid cores when the outer radius and density of the planets are constant.Although we only study special double-layered planets,these methods can be conveniently extended to complex multi-layered planets. 展开更多
关键词 INSTABILITY Double-layered PLANET GRAVITY DEFORMATION
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