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利用线性混合模型和哑变量模型方法建立贵州省通用性生物量方程 被引量:45
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作者 曾伟生 唐守正 +2 位作者 夏忠胜 朱松 罗洪章 《林业科学研究》 CSCD 北大核心 2011年第3期285-291,共7页
以贵州省人工杉木和马尾松地上生物量数据为例,通过利用线性混合模型和哑变量模型方法,建立了适合不同树种和区域(中心区和一般区)的通用性立木生物量方程,为简化生物量建模工作提供了有效途径。结果表明,相同直径林木的地上生物量估计... 以贵州省人工杉木和马尾松地上生物量数据为例,通过利用线性混合模型和哑变量模型方法,建立了适合不同树种和区域(中心区和一般区)的通用性立木生物量方程,为简化生物量建模工作提供了有效途径。结果表明,相同直径林木的地上生物量估计值随树种、区域的不同存在一定程度的差异,带随机参数的线性混合模型和带特定参数的哑变量模型比总体平均模型的精度高;线性混合模型和哑变量模型方法均同等有效,可推广应用于其它通用性模型(如材积方程)的建立。 展开更多
关键词 地上生物量 线性混合模型 哑变量模型 通用性方程 杉木 马尾松
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空间可展桁架结构动力学分析 被引量:28
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作者 赵孟良 吴开成 关富玲 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2005年第11期1669-1674,共6页
采用广义逆矩阵方法分析空间可展桁架结构的运动过程.以笛卡尔坐标系下节点的自然坐标为未知量,建立桁架结构展开过程的动力学基本方程,将约束方程嵌入动力学方程,导出一组不含乘子且方程数目等于结构自由度数的动力学方程.采用主动校... 采用广义逆矩阵方法分析空间可展桁架结构的运动过程.以笛卡尔坐标系下节点的自然坐标为未知量,建立桁架结构展开过程的动力学基本方程,将约束方程嵌入动力学方程,导出一组不含乘子且方程数目等于结构自由度数的动力学方程.采用主动校正法对数值分析的约束违约进行了修正.提出了一种切实有效的数学算法构造了约束方程及其雅可比矩阵,实时地模拟了结构收纳过程的约束条件.自行编制的仿真程序算例证明了该分析方法的正确性. 展开更多
关键词 空间可展桁架结构 广义逆 主动校正 约束方程 动力学分析
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准坐标下广义力学系统的Lie对称定理及其逆定理 被引量:30
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作者 乔永芬 赵淑红 《物理学报》 SCIE EI CAS CSCD 北大核心 2001年第1期1-7,共7页
研究准坐标下广义力学系统的Lie对称性与守恒量 .首先 ,对准坐标下广义力学系统定义无限小生成元 ,并应用微分方程在无限小变换下不变性的Lie方法 ,建立系统的确定方程 .其次 ,给出结构方程和守恒量的形式 .最后 ,研究Lie对称性逆问题 ... 研究准坐标下广义力学系统的Lie对称性与守恒量 .首先 ,对准坐标下广义力学系统定义无限小生成元 ,并应用微分方程在无限小变换下不变性的Lie方法 ,建立系统的确定方程 .其次 ,给出结构方程和守恒量的形式 .最后 ,研究Lie对称性逆问题 (由已知积分求Lie对称 )并举例说明结果的应用 . 展开更多
关键词 准坐标 LIE对称 确定方程 结构方程 守恒量 分析力学 广义力学系统 逆定理
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Representation of the constitutive equation of viscoelastic materials by the generalized fractional element networks and its generalized solutions 被引量:25
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作者 徐明瑜 谭文长 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2003年第2期145-157,共13页
The generalized fractional element networks are presented in this paper. In order to extend the structure of the model solutions to the generalized function space and make it contain more physical meanings, the restri... The generalized fractional element networks are presented in this paper. In order to extend the structure of the model solutions to the generalized function space and make it contain more physical meanings, the restriction on the parameters of the fractional element proposed by Schiessel et al. is eliminated and a 'compatibility equation' is added. The discretization method for solving the inverse Laplace transform is used and developed. The generalized solutions of the model equations are given. At the same time the generalized fractional element network--Zener and Poyinting-Thomson models are discussed in detail. It is shown that all the results obtained previously about the models of single parameter with fractional order and the classical models with integer order can be contained as the special cases of the results of this paper. 展开更多
关键词 VISCOELASTIC material CONSTITUTIVE equation generalized FRACTIONAL element networks FRACTIONAL calculus generalized solution.
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LEAST-SQUARES SOLUTION OF AXB = DOVER SYMMETRIC POSITIVE SEMIDEFINITE MATRICES X 被引量:18
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作者 AnpingLiao ZhongzhiBai 《Journal of Computational Mathematics》 SCIE CSCD 2003年第2期175-182,共8页
Least-squares solution of AXB = D with respect to symmetric positive semidefinite matrix X is considered. By making use of the generalized singular value decomposition, we derive general analytic formulas, and present... Least-squares solution of AXB = D with respect to symmetric positive semidefinite matrix X is considered. By making use of the generalized singular value decomposition, we derive general analytic formulas, and present necessary and sufficient conditions for guaranteeing the existence of the solution. By applying MATLAB 5.2, we give some numerical examples to show the feasibility and accuracy of this construction technique in the finite precision arithmetic. 展开更多
关键词 Least-squares solution Matrix equation Symmetric positive semidefinite ma- trix generalized singular value decomposition.
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A refined invariant subspace method and applications to evolution equations 被引量:21
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作者 MA Wen-Xiu 《Science China Mathematics》 SCIE 2012年第9期1769-1778,共10页
The invariant subspace method is refined to present more unity and more diversity of exact solutions to evolution equations. The key idea is to take subspaces of solutions to linear ordinary differential equations as ... The invariant subspace method is refined to present more unity and more diversity of exact solutions to evolution equations. The key idea is to take subspaces of solutions to linear ordinary differential equations as invariant subspaces that evolution equations admit. A two-component nonlinear system of dissipative equations is analyzed to shed light oi1 the resulting theory, and two concrete examples are given to find invariant subspaces associated with 2nd-order and 3rd-order linear ordinary differentii equations and their corresponding exact solutions with generalized separated variables. 展开更多
关键词 invariant subspace generalized separation of variables evolution equation
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A CLASS OF SINGULARLY PERTURBED GENERALIZED BOUNDARY VALUE PROBLEMS FOR QUASI-LINEAR ELLIPTIC EQUATION OF HIGHER ORDER 被引量:19
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作者 MO Jia-qi(莫嘉琪) +1 位作者 OUYANG Cheng(欧阳成) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第3期372-378,共7页
The singularly perturbed generalized boundary value problems far the quasi- linear elliptic equation of higher order are considered. Under suitable conditions, the existence, uniqueness and asymptotic behavior of the ... The singularly perturbed generalized boundary value problems far the quasi- linear elliptic equation of higher order are considered. Under suitable conditions, the existence, uniqueness and asymptotic behavior of the generalized solution for the Dirichlet problems are studied. 展开更多
关键词 elliptic equation singular perturbation generalized solution
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基于广义塑性力学的土体次加载面循环塑性模型(Ⅱ):本构方程与验证 被引量:12
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作者 孔亮 郑颖人 姚仰平 《岩土力学》 EI CAS CSCD 北大核心 2003年第3期349-354,共6页
按广义塑性力学原理,导出了土体次加载面循环塑性模型的本构方程,建立了相应的加卸载准则以及模型参数的确定方法。通过多种应力路径下土的本构响应的模拟,表明次加载面循环塑性模型能较好地反映循环荷载作用下土体呈现的非线性、滞回... 按广义塑性力学原理,导出了土体次加载面循环塑性模型的本构方程,建立了相应的加卸载准则以及模型参数的确定方法。通过多种应力路径下土的本构响应的模拟,表明次加载面循环塑性模型能较好地反映循环荷载作用下土体呈现的非线性、滞回性与变形的积累性三方面主要特征,初步验证了模型的有效性。 展开更多
关键词 广义塑性力学 次加载面 循环塑性 本构方程
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New Exact Travelling Wave Solutions for Generalized Zakharov-Kuzentsov EquationsUsing General Projective Riccati Equation Method 被引量:14
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作者 CHENYong LIBiao 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第1期1-6,共6页
Applying the generalized method, which is a direct and unified algebraic method for constructing multipletravelling wave solutions of nonlinear partial differential equations (PDEs), and implementing in a computer alg... Applying the generalized method, which is a direct and unified algebraic method for constructing multipletravelling wave solutions of nonlinear partial differential equations (PDEs), and implementing in a computer algebraicsystem, we consider the generalized Zakharov-Kuzentsov equation with nonlinear terms of any order. As a result, wecan not only successfully recover the previously known travelling wave solutions found by existing various tanh methodsand other sophisticated methods, but also obtain some new formal solutions. The solutions obtained include kink-shapedsolitons, bell-shaped solitons, singular solitons, and periodic solutions. 展开更多
关键词 projective Riccati equation method generalized Zakharov-Kuzentsov equation exact solutions
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The attractor of the stochastic generalized Ginzburg-Landau equation 被引量:11
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作者 GUO BoLing~1 WANG GuoLian~(2+) Li DongLong~3 1 Institute of Applied Physics and Computational Mathematics,P.O.Box 8009,Beijing 100088,China 2 The Graduate School of China Academy of Engineering Physics,P.O.Box 2101,Beijing 100088,China 3 Department of Information and Computer Science,Guangxi University of Technology,Liuzhou 545006,China 《Science China Mathematics》 SCIE 2008年第5期955-964,共10页
The stochastic generalized Ginzburg-Landau equation with additive noise can be solved pathwise and the unique solution generates a random system. Then we prove the random system possesses a global random attractor in ... The stochastic generalized Ginzburg-Landau equation with additive noise can be solved pathwise and the unique solution generates a random system. Then we prove the random system possesses a global random attractor in H 0 1 . 展开更多
关键词 generalized Ginzburg-Landau equation random dynamical systems random attractor 35K05
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Symmetry Reductions and Explicit Solutions for a Generalized Zakharov-Kuznetsov Equation 被引量:12
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作者 YAN Zhi-Lian LIU Xi-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1期29-32,共4页
Two types of symmetry of a generalized Zakharov-Kuznetsov equation are obtained via a direct symmetry method. By selecting suitable parameters occurring in the symmetries, we also find some symmetry reductions and new... Two types of symmetry of a generalized Zakharov-Kuznetsov equation are obtained via a direct symmetry method. By selecting suitable parameters occurring in the symmetries, we also find some symmetry reductions and new explicit solutions of the generalized Zakharov-Kuznetsov equation. 展开更多
关键词 generalized Zakharov-Kuznetsov equation SYMMETRY explicit solution
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利用混合模型方法建立全国和区域相容性立木生物量方程 被引量:12
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作者 曾伟生 唐守正 《中南林业调查规划》 2010年第4期1-6,共6页
开展全国森林生物量监测和评估,建立适合较大区域范围的通用性立木生物量模型将成为必然趋势,而如何保证不同尺度范围森林生物量估计值的相容性,是必须面临的一个问题。以南方马尾松(Pinus massoniana)地上生物量数据为例,通过利用混合... 开展全国森林生物量监测和评估,建立适合较大区域范围的通用性立木生物量模型将成为必然趋势,而如何保证不同尺度范围森林生物量估计值的相容性,是必须面临的一个问题。以南方马尾松(Pinus massoniana)地上生物量数据为例,通过利用混合模型方法,同时建立全国和区域性立木生物量方程,为解决不同区域尺度范围内森林生物量估计的相容性问题提供有效途径。从模型反映的结果看,相同直径林木的地上生物量估计值随起源、地域的不同存在一定程度的差异,其差异大小可以通过混合模型中的随机效应来估计。该方法可推广应用于其它通用性模型(如材积方程)的建立。 展开更多
关键词 立木生物量 地上生物量 混合效应回归模型 通用性方程 相容性 马尾松
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Explicit Solutions for Generalized (2+1)-Dimensional Nonlinear Zakharov-Kuznetsov Equation 被引量:9
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作者 孙峪怀 马志民 李燕 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第9期397-400,共4页
The exact solutions of the generalized (2+1)-dimensional nonlinear Zakharov-Kuznetsov (Z-K) equationare explored by the method of the improved generalized auxiliary differential equation.Many explicit analytic solutio... The exact solutions of the generalized (2+1)-dimensional nonlinear Zakharov-Kuznetsov (Z-K) equationare explored by the method of the improved generalized auxiliary differential equation.Many explicit analytic solutionsof the Z-K equation are obtained.The methods used to solve the Z-K equation can be employed in further work toestablish new solutions for other nonlinear partial differential equations. 展开更多
关键词 generalized nonlinear Zakharov-Kuznetsov equation improved generalized auxiliary differentialequation and exact solutions
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Generalized equation for calculating rock cutting efficiency by pulsed water jets 被引量:8
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作者 Andrey Polyakov Aleksandr Zhabin +1 位作者 Eugene Averin Aleksey Polyakov 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2019年第4期867-873,共7页
One of the promising methods for rock cutting technology is the use of high-speed water jets.In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment,pulsed water jets... One of the promising methods for rock cutting technology is the use of high-speed water jets.In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment,pulsed water jets are basically used to increase the rock cutting efficiency.However,there are no mature recommendations for selection of rational parameters,and the relationship between indicators of rock cutting efficiency and parameters of pulsed water jet is still not established.In this context,we aimed at developing a generalized equation for calculating rock cutting efficiency,in which all the major parameters in consideration of rock cutting process are included.Then,a calibration of the rational parameters of rock cutting by pulsed water jets was conducted.The results are likely helpful for increasing productivity and reducing energy consumption. 展开更多
关键词 PULSED WATER jets Rock CUTTING WATER JET technology generalized equation Depth of CUT
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用于积分方程解的广义逆函数值Padé 逼近的ε-算法和η-算法 被引量:6
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作者 李春景 顾传青 《应用数学和力学》 EI CSCD 北大核心 2003年第2期197-204,共8页
 为加速具有函数值系数的幂级数收敛并估计积分方程的特征值,建立了两个计算广义逆函数值Pad啨逼近的有效的递推算法:ε_算法和η_算法· 借助于这两个算法之间的内在关系。
关键词 广义逆 函数值Pade逼近 ε-算法 η-算法 积分方程
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Effective generalized equations of secure hyperelliptic curve digital signature algorithms 被引量:7
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作者 YOU Lin ,SANG Yong-xuan College of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,China 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2010年第2期100-108,115,共10页
A hyperelliptic curve digital signature algorithm (HECDSA) can be viewed as the hyperelliptic curve analogue of the standard digital signature algorithm (DSA). This article discusses divisor evaluations, the basic... A hyperelliptic curve digital signature algorithm (HECDSA) can be viewed as the hyperelliptic curve analogue of the standard digital signature algorithm (DSA). This article discusses divisor evaluations, the basic HECDSA, variants, two HECDSA equations and a 4-tuple HECDSA scheme, and puts forward a generalized equation for HECDSA. From this generalized equation, seven general HECDSA types are derived based on the efficiency requirements. Meanwhile, the securities of these general HECDSA types are analyzed in detail. 展开更多
关键词 hyperelliptic curve digital signature algorithm generalized equation hyperelliptic curve discrete logarithm problem
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Exact Traveling Wave Solutions for a Kind of Generalized Ginzburg-Landau Equation 被引量:8
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作者 LIUCheng-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期787-790,共4页
Using a complete discrimination system for polynomials, new exact traveling wave solutions for generalized Ginzburg-Landau equation are obtained. The method has general meaning for many similar problems.
关键词 generalized Ginzburg-Landau equation elementary integral method polynomialcomplete discrimination system
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STOCHASTIC DIFFERENTIAL EQUATIONS AND STOCHASTIC LINEAR QUADRATIC OPTIMAL CONTROL PROBLEM WITH LEVY PROCESSES 被引量:7
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作者 Huaibin TANG Zhen WU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2009年第1期122-136,共15页
In this paper, tile authors first study two kinds of stochastic differential equations (SDEs) with Levy processes as noise source. Based on the existence and uniqueness of the solutions of these SDEs and multi-dimen... In this paper, tile authors first study two kinds of stochastic differential equations (SDEs) with Levy processes as noise source. Based on the existence and uniqueness of the solutions of these SDEs and multi-dimensional backward stochastic differential equations (BSDEs) driven by Levy pro- cesses, the authors proceed to study a stochastic linear quadratic (LQ) optimal control problem with a Levy process, where the cost weighting matrices of the state and control are allowed to be indefinite. One kind of new stochastic Riccati equation that involves equality and inequality constraints is derived from the idea of square completion and its solvability is proved to be sufficient for the well-posedness and the existence of optimal control which can be of either state feedback or open-loop form of the LQ problems. Moreover, the authors obtain the existence and uniqueness of the solution to the Riccati equation for some special cases. Finally, two examples are presented to illustrate these theoretical results. 展开更多
关键词 Backward stochastic differential equation generalized stochastic Riccati equation Levy process stochastic linear quadratic optimal control.
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柔性两轮直立式自平衡仿人机器人的建模及控制 被引量:5
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作者 赵建伟 阮晓钢 《机器人》 EI CSCD 北大核心 2009年第2期179-186,共8页
研究了柔性两轮直立式自平衡仿人机器人的动力学建模问题.运用拉格朗日方法和动力学原理建立了柔性两轮自平衡仿人机器人的动力学模型.使用弹簧模仿人的腰椎,并考虑了机器人的柔性腰椎弯曲;这是与以前机器人的不同之处.对得到的动力学... 研究了柔性两轮直立式自平衡仿人机器人的动力学建模问题.运用拉格朗日方法和动力学原理建立了柔性两轮自平衡仿人机器人的动力学模型.使用弹簧模仿人的腰椎,并考虑了机器人的柔性腰椎弯曲;这是与以前机器人的不同之处.对得到的动力学模型进行了线性化处理,并建立其状态空间方程;由此建立的动力学模型结构简单,易于对机器人进行有效控制.仿真实验验证了系统的稳定性,对其实验结果进行的详细分析验证了系统建模和LQR控制器设计的合理性和有效性. 展开更多
关键词 柔性机器人 动力学建模 广义坐标 拉格朗日方程 腰椎
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Symmetry Groups and New Exact Solutions to (2+1)-Dimensional Variable Coefficient Canonical Generalized KP Equation 被引量:7
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作者 ZHANG Li-Hua LIU Xi-Qiang BAI Cheng-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3X期405-410,共6页
In this paper, the modified CK's direct method to find symmetry groups of nonlinear partial differential equation is extended to (2+1)-dimensional variable coeffficient canonical generalized KP (VCCGKP) equation... In this paper, the modified CK's direct method to find symmetry groups of nonlinear partial differential equation is extended to (2+1)-dimensional variable coeffficient canonical generalized KP (VCCGKP) equation. As a result, symmetry groups, Lie point symmetry group and Lie symmetry for the VCCGKP equation are obtained. In fact, the Lie point symmetry group coincides with that obtained by the standard Lie group approach. Applying the given Lie symmetry, we obtain five types of similarity reductions and a lot of new exact solutions, including hyperbolic function solutions, triangular periodic solutions, Jacobi elliptic function solutions and rational solutions, for the VCCGKP equation. 展开更多
关键词 (2+1)-dimensional variable coefficient canonical generalized KP (VCCGKP) equation modified CK's'direct method symmetry groups Lie symmetry similarity reductions new exact solutions
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