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Invariant sets and solutions to the generalized thin film equation 被引量:15
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作者 Chang-zheng QU & Chun-rong ZHU Center for Nonlinear Studies, Northwest University, Xi’an 710069, China Department of Mathematics, Northwest University, Xi’an 710069, China Department of Mathematics, Anhui Normal University, Wuhu 241000, China 《Science China Mathematics》 SCIE 2007年第6期875-886,共12页
The invariant sets and the solutions of the 1+2-dimensional generalized thin film equation are discussed. It is shown that there exists a class of solutions to the equations, which are invariant with respect to the se... The invariant sets and the solutions of the 1+2-dimensional generalized thin film equation are discussed. It is shown that there exists a class of solutions to the equations, which are invariant with respect to the set $$E_0 = \{ u:u_x = v_x F(u),u_y = v_y F(u)\} ,$$ where v is a smooth function of variables x, y and F is a smooth function of u. This extends the results of Galaktionov (2001) and for the 1+1-dimensional nonlinear evolution equations. 展开更多
关键词 thin film equation invariant set invariant solution rotation group scaling group 35K55 35K40 82C26
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Existence,uniqueness and stability of C^m solutions of iterative functional equations 被引量:14
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作者 麦结华 刘新和 《Science China Mathematics》 SCIE 2000年第9期897-913,共17页
In this paper we discuss a relatively general kind of iterative functional equation G(x,f(x), ...,f n (x)) = 0 (for allx ∈J), whereJ is a connected closed subset of the real number axis ?,G∈C m (J n+1, ?) andn ≥ 2.... In this paper we discuss a relatively general kind of iterative functional equation G(x,f(x), ...,f n (x)) = 0 (for allx ∈J), whereJ is a connected closed subset of the real number axis ?,G∈C m (J n+1, ?) andn ≥ 2. Using the method of approximating fixed points by small shift of maps, choosing suitable metrics on functional spaces and finding a relation between uniqueness and stability of fixed points of maps of general spaces, we prove the existence, uniqueness and stability ofCm solutions of the above equation for any integer m ≥ 0 under relatively weak conditions, and generalize related results in reference in different aspects. 展开更多
关键词 iterative functional equation C m map function space compact convex set flxed point diagonal method
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船舶粘流计算软件“OShip”开发 被引量:12
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作者 周秀红 赵发明 王丽艳 《中国造船》 EI CSCD 北大核心 2014年第1期90-103,共14页
论文系统阐述了船舶粘流计算软件"OShip"的数值处理及其功能实现方法,软件基于重叠网格技术,采用RANS方程模拟船舶粘性兴波流场,实现对船舶水动力性能的精细预报。通过静态和动态计算实例验证了其对船舶快速性、操纵性、耐波... 论文系统阐述了船舶粘流计算软件"OShip"的数值处理及其功能实现方法,软件基于重叠网格技术,采用RANS方程模拟船舶粘性兴波流场,实现对船舶水动力性能的精细预报。通过静态和动态计算实例验证了其对船舶快速性、操纵性、耐波性以及螺旋桨敞水性能的计算效率和精度。该软件功能全面、操作简便,是精细预报船舶水动力性能的有效工具。 展开更多
关键词 重叠网格 RANS方程 单相Level set方法 粘流计算
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消错规划求解研究 被引量:10
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作者 郭开仲 闵惜琳 《广东工业大学学报》 CAS 2010年第1期1-7,共7页
在错误矩阵的研究基础上,研究用错误矩阵方程表示系统资源约束和用对象集合表示条件与人为约束的消错规划优化模型.对两类规划错误矩阵方程,一类:AX=B、A●X=B、A▲X=B、A∨X=B、A∧X=B;二类:XA=B、X●A=B、X▲A=B、X∨A=B、X∧A=B,本... 在错误矩阵的研究基础上,研究用错误矩阵方程表示系统资源约束和用对象集合表示条件与人为约束的消错规划优化模型.对两类规划错误矩阵方程,一类:AX=B、A●X=B、A▲X=B、A∨X=B、A∧X=B;二类:XA=B、X●A=B、X▲A=B、X∨A=B、X∧A=B,本文基于二类1方程XA=B与客观、人为、需求等3种限制构成规划模型,并研究此规划的求解方法、解的存在性、解的形式,并进一步研究了这类消错规划模型规划的求解,最后给出了一个应用示例. 展开更多
关键词 消错规划 系统优化 错误矩阵 集合方程
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Mather Sets for Superlinear Dulling Equations 被引量:5
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作者 裴明亮 《Science China Mathematics》 SCIE 1993年第5期524-537,共14页
In this paper, we apply Aubry-Mather theory developed in recent years about monotone twist mappings to the study of the superlinear Duffing equation+g(x)=p(t), (0)where p(t)∈C^0(R) is periodic with period 1 and g(x) ... In this paper, we apply Aubry-Mather theory developed in recent years about monotone twist mappings to the study of the superlinear Duffing equation+g(x)=p(t), (0)where p(t)∈C^0(R) is periodic with period 1 and g(x) satisfies the superlinearity condition Consequently, this gives descriptions of the global dynamical behavior, particularly periodic solutions and quasi-periodic solutions of a wide class of Eq. (0), not requiring high order smoothness assumption. 展开更多
关键词 DUFFING equation Aubry-Mather theory Mather set unlinked PERIODIC SOLUTIONS QUASI-PERIODIC solutions.
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基于包含型错误矩阵方程的消错规划求解研究 被引量:6
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作者 郭开仲 闵惜琳 《广东工业大学学报》 CAS 2010年第3期12-15,共4页
在错误矩阵的研究基础上,研究用错误矩阵方程表示系统资源约束和用对象集合表示条件与人为约束的消错规划优化模型.基于XA′B与客观、人为、需求等3种限制构成规划模型,并研究此规划的求解方法、解的存在性、解的形式.
关键词 消错规划 系统优化 错误矩阵 集合方程
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复集理论 被引量:1
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作者 孙桂秋 《益阳师专学报》 1994年第6期1-7,共7页
本文是[6]的续篇,是对经典集合的进一步扩张。
关键词 复集 实集 论域 虚集 零集 集函数 集方程
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THE EXISTENCE OF SOLUTIONS OF NONLINEARFREDHOLM INTEGRAL EQUATIONS IN BANACH SPACES 被引量:3
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作者 闫宝强 史国良 《Acta Mathematica Scientia》 SCIE CSCD 1998年第S1期114-119,共6页
This paper improves Tychonov ford point theorem and discusses the existence of solutions of nonlinear Fredholm integral equations on [0,+∞] in Banach spaces with Frechet space theory.
关键词 Fredholm equation Kuratowski measure of noncompactness locally equicontinuous set
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A Study Regarding Solution of a Knowledge Model Based on the Containing-Type Error Matrix Equation 被引量:1
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作者 Xilin Min Kaizhong Guo Jize Huang 《Engineering(科研)》 2012年第8期484-492,共9页
An error matrix equation based on error matrix theory was presented in previous research of the error-eliminating theory. The purpose of solving the error matrix equation is to create a decision support on how to swit... An error matrix equation based on error matrix theory was presented in previous research of the error-eliminating theory. The purpose of solving the error matrix equation is to create a decision support on how to switch from bad to good status. A matrix based on error logic is used to express current status u, expectant status u1 and transformation matrix T. It is u, u1, and T that are used to build error matrix equation T (u)= u1. This allows us to find a method whereby bad status “u” changes to good status “u1” by solving the equation. The conversion method that transform from current to expectant status can be obtained from the transformation matrix T. On this basis, this paper proposes a new kind of error matrix equation named “containing-type error matrix equation”. This equation is more suitable for analyzing the realistic question. The method of solving, existence and form of solution for this type of equation have been presented in this paper. This research provides a potential useful new technique for decision analysis. 展开更多
关键词 ERROR MATRIX set equation Containing-Type ERROR MATRIX equation KNOWLEDGE Model
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The property of solutions for the equations of large-scale atmosphere with the non-stationary external forcings 被引量:2
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作者 李建平 丑纪范 《Chinese Science Bulletin》 SCIE EI CAS 1996年第7期587-590,共4页
The long-term behavior of the atmospheric evolution, which cannot be answered and solvedby the numerical experiments, must be undrstood before we design the numerical forecastmodels of the long-range weather and clima... The long-term behavior of the atmospheric evolution, which cannot be answered and solvedby the numerical experiments, must be undrstood before we design the numerical forecastmodels of the long-range weather and climate. It is necessary to carry out some studiesof basic theory. Based on the stationary external forcings, Chou studied the adjustment of the nonlinear atmospheric system tending to forcings in R^n. Then these resultswere extended to the infinite dimensional Hilbert space. For the real atmospheric system, 展开更多
关键词 solution of the ATMOSPHERIC equationS NON-STATIONARY external FORCING absorbing set OPERATOR equation.
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Solution for generalized fuzzy fractional Kortewege-de Varies equation using a robust fuzzy double parametric approach 被引量:2
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作者 L.Verma R.Meher +1 位作者 Z.Avazzadeh O.Nikan 《Journal of Ocean Engineering and Science》 SCIE 2023年第6期602-622,共21页
The nonlinear Kortewege-de Varies(KdV)equation is a functional description for modelling ion-acoustic waves in plasma,long internal waves in a density-stratified ocean,shallow-water waves and acoustic waves on a cryst... The nonlinear Kortewege-de Varies(KdV)equation is a functional description for modelling ion-acoustic waves in plasma,long internal waves in a density-stratified ocean,shallow-water waves and acoustic waves on a crystal lattice.This paper focuses on developing and analysing a resilient double parametric analytical approach for the nonlinear fuzzy fractional KdV equation(FFKdVE)under gH-differentiability of Caputo fractional order,namely the q-Homotopy analysis method with the Shehu transform(q-HASTM).A triangular fuzzy number describes the Caputo fractional derivative of orderα,0<α≤1,for modelling problem.The fuzzy velocity profiles with crisp and fuzzy conditions at different spatial positions are in-vestigated using a robust double parametric form-based q-HASTM with its convergence analysis.The ob-tained results are compared with existing works in the literature to confirm the efficacy and effectiveness of the method. 展开更多
关键词 Fuzzy set Double parametric approach Hukuhara differentiability Shehu transform KdV equation q-HAShTM Caputo fractional derivative
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PARAMETRIC EQUATION SOLVING AND QUANTIFIER ELIMINATION IN FINITE FIELDS WITH THE CHARACTERISTIC SET METHOD 被引量:3
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作者 Zhenyu HUANG 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2012年第4期778-791,共14页
For a parametric algebraic system in finite fields, this paper presents a method for computing the cover and the refined cover based on the characteristic set method. From the cover, the author knows for what parametr... For a parametric algebraic system in finite fields, this paper presents a method for computing the cover and the refined cover based on the characteristic set method. From the cover, the author knows for what parametric values the system has solutions and at the same time presents the solutions in the form of proper chains. By the refined cover, the author gives a complete classification of the number of solutions for this system, that is, the author divides the parameter space into several disjoint components, and on every component the system has a fix number of solutions. Moreover, the author develops a method of quantifier elimination for first order formulas in finite fields. 展开更多
关键词 Characteristic set method finite field parametric equation system quantifier elimination.
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B-模糊集合代数和广义互信息公式 被引量:3
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作者 鲁晨光 《模糊系统与数学》 CSCD 1991年第1期76-80,共5页
基于两种概率的区分,推导出了一个广义Shannon熵公式和一个广义互信息公式。后者和模糊性有关,并且可用于语言和感觉中的信息度量。为了由原子语句为真的条件概率求出复合语句为真的条件概率,提出了一个遵循布尔运算的模糊集合代数。所... 基于两种概率的区分,推导出了一个广义Shannon熵公式和一个广义互信息公式。后者和模糊性有关,并且可用于语言和感觉中的信息度量。为了由原子语句为真的条件概率求出复合语句为真的条件概率,提出了一个遵循布尔运算的模糊集合代数。所谓的模糊信息被还原为概率信息。新的理论在经典理论——概率论,集合论及Shannon信息论——的基础上容易理解。 展开更多
关键词 B-模糊集合代数 广义互信息公式 模糊集合 Shannon公式 概率 语言信息 感觉信息
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Exponential Attractor for a Nonlinear Boussinesq Equation 被引量:1
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作者 Ahmed Y. Abdallah 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2006年第3期443-450,共8页
This paper is devoted to prove the existence of an exponential attractor for the semiflow generated by a nonlinear Boussinesq equation. We formulate the Boussinesq equation as an abstract equation in the Hilbert space... This paper is devoted to prove the existence of an exponential attractor for the semiflow generated by a nonlinear Boussinesq equation. We formulate the Boussinesq equation as an abstract equation in the Hilbert space H0^2(0, 1) × L^2(0, 1). The main step in this research is to show that there exists an absorbing set for the solution semiflow in the Hilbert space H0^3(0, 1) × H0^1(0, 1). 展开更多
关键词 Boussinesq equation absorbing set exponential attractor
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Likely Limit Sets of a Class of p-order Feigenbaum's Maps 被引量:1
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作者 WANG WEI LIAO LI 《Communications in Mathematical Research》 CSCD 2012年第2期137-145,共9页
A continuous map from a closed interval into itself is called a p-order Feigenbaum's map if it is a solution of the Feigenbaum's equation fP(λx)=λf(x). In this paper, we estimate Hausdorff dimensions of likely... A continuous map from a closed interval into itself is called a p-order Feigenbaum's map if it is a solution of the Feigenbaum's equation fP(λx)=λf(x). In this paper, we estimate Hausdorff dimensions of likely limit sets of some p-order Feigenbaum's maps. As an application, it is proved that for any 0 〈 t 〈 1, there always exists a p-order Feigenbaum's map which has a likely limit set with Hausdorff dimension t. This generalizes some known results in the special case of p =2. 展开更多
关键词 Feigenbaum's equation Feigenbaum's map likely limit set Hausdorff dimension
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Empirical likelihood for balanced ranked-set sampled data 被引量:1
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作者 LIU TianQing LIN Nan ZHANG BaoXue 《Science China Mathematics》 SCIE 2009年第6期1351-1364,共14页
Ranked-set sampling(RSS) often provides more efficient inference than simple random sampling(SRS).In this article,we propose a systematic nonparametric technique,RSS-EL,for hypoth-esis testing and interval estimation ... Ranked-set sampling(RSS) often provides more efficient inference than simple random sampling(SRS).In this article,we propose a systematic nonparametric technique,RSS-EL,for hypoth-esis testing and interval estimation with balanced RSS data using empirical likelihood(EL).We detail the approach for interval estimation and hypothesis testing in one-sample and two-sample problems and general estimating equations.In all three cases,RSS is shown to provide more efficient inference than SRS of the same size.Moreover,the RSS-EL method does not require any easily violated assumptions needed by existing rank-based nonparametric methods for RSS data,such as perfect ranking,identical ranking scheme in two groups,and location shift between two population distributions.The merit of the RSS-EL method is also demonstrated through simulation studies. 展开更多
关键词 empirical likelihood ranked-set sampling testing hypotheses confidence interval estimating equation 62G10
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Additive Rate Model With Auxiliary Covariates 被引量:1
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作者 Zhi-bin XU Lu-qin LIU Yan-yan LIU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2017年第1期125-140,共16页
In this paper, we consider an inference method for recurrent event data in which the primary exposure covariate is assessed only in a validation set, while as an auxiliary covariate for the main exposure is available ... In this paper, we consider an inference method for recurrent event data in which the primary exposure covariate is assessed only in a validation set, while as an auxiliary covariate for the main exposure is available for the full cohort. Additive rate model is considered. The existing estimating equations in the absence of primary exposure are corrected by taking use of the validation data and auxiliary information, which yield consistent and asymptotically normal estimators of the regression parameters. The estimated baseline mean process is shown to converge weakly to a zero-mean Gaussian process. Extensive simulations are conducted to evaluate finite sample performance. 展开更多
关键词 additive rate model recurrent event data auxiliary covariate estimating equation validation set
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小振幅驻波的数值计算 被引量:1
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作者 汪迎春 汪德 崔海滨 《水利水电科技进展》 CSCD 北大核心 2007年第1期14-16,共3页
将快速行进法和源点扫描法的思想结合起来,改进了非结构网格下Level Set方法的实现策略,结合人工压缩法,求解小振幅驻波问题。对2种不同波幅的驻波分别进行了计算,结果和理论吻合较好。计算中Level Set策略很稳定,没有产生数值性的破碎... 将快速行进法和源点扫描法的思想结合起来,改进了非结构网格下Level Set方法的实现策略,结合人工压缩法,求解小振幅驻波问题。对2种不同波幅的驻波分别进行了计算,结果和理论吻合较好。计算中Level Set策略很稳定,没有产生数值性的破碎,表明改进后的Level Set方法可用于不同幅度振幅波问题的计算。 展开更多
关键词 N—S方程 驻波 LEVEL set 人工压缩
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Numerical study of detonation shock dynamics using generalized finite difference method 被引量:2
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作者 CHEN YongLi HUANG KuiBang YU Xin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第10期1883-1888,共6页
The generalized finite difference method (GFDM) used for irregular grids is first introduced into the numerical study of thelevel set equation, which is coupled with the theory of detonation shock dynamics (DSD) descr... The generalized finite difference method (GFDM) used for irregular grids is first introduced into the numerical study of thelevel set equation, which is coupled with the theory of detonation shock dynamics (DSD) describing the propagation of thedetonation shock front. The numerical results of a rate-stick problem, a converging channel problem and an arc channel prob-lem for specified boundaries show that GFDM is effective on solving the level set equation in the irregular geometrical domain.The arrival time and the normal velocity distribution of the detonation shock front of these problems can then be obtainedconveniently with this method. The numerical results also confirm that when there is a curvature effect, the theory of DSDmust be considered for the propagation of detonation shock surface, while classic Huygens construction is not suitable anymore. 展开更多
关键词 generalized finite difference method detonation shock dynamics level set equation propagation of detonation shockfront irregular grids
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MATLAB在车辆动力学中的应用研究 被引量:1
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作者 罗文俊 蒋先刚 李中奇 《华东交通大学学报》 2004年第5期8-11,共4页
通过分析传统车辆横向振动建模的不足,提出了建立轮对横向振动的非线性动态模型.给出了应用于单个轮对数字建模的具体实例,重点介绍了简捷地求解轮对非线性动力学微分方程的方法,并提供了相应例程及仿真结果.
关键词 车辆动力学 轮对 横向振动 实例 建模 非线性动力学 微分方程 例程 仿真结果 求解
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