共查询到20条相似文献,搜索用时 234 毫秒
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Littlewood—Paley算子及Marcinkiewicz积分在Campanato空间εa,p上的有界性 总被引:1,自引:0,他引:1
我们证明了下述结果:若f∈εa,p,则适当限制参数值时,有g(f)(x)(S(f)(x),gλ*(f)(x),μ(f)(x))<∞a.e.,或者g(f)(x)(S(f)(x),gλ*(f)(x),μ(f)(x))<∞a.e.;并且在前者成立时,有g(f)(S(f),gλ*(f),μ(f))∈εa,p,以及‖g(f)‖a,p 相似文献
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关于微分差分方程的边值问题 总被引:9,自引:0,他引:9
本文考虑含小参数ε>0且自变量具有固定时滞1的微分差分方程边值问题(?)其中L[y(x,ε)]=εy″(x,ε)-a(x,ε)y′(x,ε)-b(x,ε)y(x,ε),R[y(x,ε)]=A(x,ε)y′(x-1,ε)+B(x,ε)y(x-1,ε)+f(x,ε),T 是一正数,10下讨论了边值问题解的存在性、唯一性和区间-1≤x≤T 上当ε→0~+时解的一致有效估计. 相似文献
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鞍点分界线圈的稳定性及其分支出极限环的条件 总被引:12,自引:5,他引:7
<正> 考虑系统(?)=p_0(x,y)+εP_1(x,y,ε),(?)=Q_0(x,y)+εQ_1(x,y,ε).其中 P_0,Q_0对 x,y、P_1,Q_1对 x,y,ε具有我们所需要的任何程度的光滑性.例如,可设它们是 C~2类的或解析的等等. 相似文献
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我们证明了下述结果:若f∈ε~(a,p),则适当限制参数值时,有g(f)(x)(S(f)(x),g_λ~*(f)(x),μ(f)(x))<∞a.e.,或者g(f)(x)(S(f)(x),g_λ~*(f)(x),μ(f)(x))<∞a.e.;并且在前者成立时,有g(f)(S(f),g_λ~*(f),μ(f)∈ε~(a,p),以及,其中C为不依赖于f的常数. 相似文献
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我们研究二阶Hamiltonian系统-ü=▽F1(t,u)+ε▽F2(t,u)a.e.t∈[0,T]的多重周期解,其中ε是一个参数,T0.F1(F2)∶R×RN→R关于t是T周期的,▽F1(t,x)关于x是奇的;并且Fi(t,x)(i=1,2)对所有x∈RN关于t是可测的,对几乎所有t∈[0,T]关于x是连续可微的,而且存在a∈C(R+,R+),b∈L+(0,T;R+)使得|Fi(t,x)|≤a(|x|)b(t),|▽Fi(t,x)|≤a(|x|)b(t)对所有x∈RN及几乎所有t∈[0,T]成立.我们对F1施加适当的条件,能够证明对任意的j∈N存在εj0使得|ε|≤εj,则上述问题至少有j个不同的周期解. 相似文献
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本文研究摄动边值问题dx/dt=f(x,y,t;ε),εdy/dt=g(x,y,t;ε),a1(ε)x(0,ε)+a2(ε)y(0,ε)=a(ε)b1(ε)x(1,ε)+εb2(ε)y(1,ε)=β(ε)这里x,f,β∈Em,y,g,a∈En,0<ε《1,a1(ε),a2(ε),b1(ε),b2(ε)为适当阶数的矩阵.在gy(t)是非奇异矩阵及其它的适当限制下,证明了解的存在唯一性,作出了解的n阶渐近近似式,并得出余项估计. 相似文献
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杨宏伟 《高等学校计算数学学报》2001,23(3):273-280
1 引 言考虑非齐次守恒律方程ut+f(u) x =g(u) , -∞ 0 ,(1 .1 )u(x,0 ) =u0 (x) , -∞ 0 , (1 .5)g∈ C3且 g是 Lipschitz连续的 ,Lipschitz系数为 L . (1 .6 )对于一般守恒律齐次方程 ,粘性解逼近熵解的收敛阶为 O(ε ) [1 ] .在 f严格凸的条件下 ,其收敛速度可以提高到 O(ε|lnε|+ε) [2 ] ,[3] .本文考虑具有条件 (1 .5) (1 .6 )的非齐次方程(1 .1 ) ,在较广泛的一类初值条件下… 相似文献
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Lars-Erik Thorelli 《BIT Numerical Mathematics》1974,14(3):338-346
The main features of a time-sharing system for a minicomputer are outlined. An interpretive language LAX plays a central role in the system both as a base for the languages seen by the user and for implementing part of the system. The system is open-ended, new subsystems can be plugged in easily, and a variety of error and interrupt behavior can be obtained. 相似文献
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The dynamical behavior of a drill-string is defined by its small diameter-to-length ratio, which makes the string vulnerable to torsional vibrations. In combination with the nonlinear friction characteristic at the drill bit, this can lead to self-excited stick-slip vibrations which are detrimental to the drilling process. The string can be modeled by the Finite Element Method or as a Multi-Body system to represent the distributed character of the system. The analysis of the resulting high-dimensional model is, however, elaborate and time-consuming. We show that through Galerkin Projection onto the first two Characteristic Functions gained from Karhunen-Loève-Transformation, a reduced system can be obtained which reproduces the essential dynamical properties of the original system, e.g. the stick-slip motion. With the reduced system, the linear stability of the drill-string can be analyzed. We show that by reducing the inertia of the rotary table the system can be stabilized. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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轴承-转子系统分岔参数的分维数识别法 总被引:2,自引:0,他引:2
广泛用于各行各业的转子系统的稳定性问题一直倍受关注.而在当今失稳多是由于一些非线性现象的出现所引起,这就对转子系统的设计提出了更高的要求:考虑非线性因素,避开会出现非线性现象的不稳定参数点或区域.若仅知未知系统的系列时间序列(有可能被噪声污染),如何识别系统运动性态的变化?为了探讨此问题,在本文中通过对一单盘Jeffcott转子的研究,得出了利用随参数变化的时间序列分维数趋势图,可以很好地识别轴承-转子动力系统发生分岔时的临界参数. 相似文献
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FI代数同构于一族全序FI代数的直积的子代数的条件 总被引:5,自引:0,他引:5
解决了王国俊教授提出的关于FI代数的嵌入问题,并进一步研究了FI代数与一族全序FI代数的直积的子代数同构的条件.主要结果是:交换FI代数可同构嵌入一族全序交换FI代数的直积;分配FI代数可同构嵌入一族全序分配FI代数的直积. 相似文献
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Y. H. Chen 《Journal of Optimization Theory and Applications》1996,90(3):605-626
We consider the robust control design problem for a class of nonlinear uncertain systems. The uncertainty in the system may be due to parameter variations and/or nonlinearity. It may be possibly fast, time-varying. The system does not satisfy the so-called matching condition. Under a state transformation, which is based on the possible bound of the uncertainty, a robust control scheme can be designed. The control renders the original uncertain system practically stable. Furthermore, the uniform ultimate boundedness ball and uniform stability ball of the original system can be made arbitrarily small by suitable choice of design parameters. 相似文献
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Uniqueness of limit cycles of the predator-prey system with Beddington-DeAngelis functional response
Tzy-Wei Hwang 《Journal of Mathematical Analysis and Applications》2004,290(1):113-122
The goal of this paper is to establish the uniqueness of limit cycles of the predator-prey systems with Beddington-DeAngelis functional response. Through a change of variables, the predator-prey system can be transformed into a better studied Gause-type predator-prey system. As a result, the uniqueness of limit cycles can be solved. 相似文献
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A linear time-invariant discrete system with a single bounded control input is considered. Various types of constraints imposed on the control input are investigated. The set of system states that can be reached from the origin (reachable set) is studied. The set of system states from where the origin can be reached (null-controllable set) is studied as well. Various examples are presented. 相似文献
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S.P. BERGE T.I. FOSSEN 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(4):365-381
Nonlinear ship control systems can be designed by exploiting system properties like passivity and dissipativeness in nonlinear system. The nonlinear ship model is written in a vectorial setting with emphasis placed on matrix properties like positiveness, symmetry and skew-symmetry. As a result of energy conservation the ship dynamics can be considered as two interconnected systems. The first system describes the dissipative motion of the rigid-body (ship) while the second system represents the forces due to potential theory generated by the ambient water particles. It is shown that for a stable ship, both subsystems are passive as well as the interconnected system. For an unstable ship, the ambient water system is input feedforward passive with shortage of passivity and therefore the ship must be stabilized by positive feedback. The structural properties of the nonlinear equations of motion are exploited in the Lyapunov analysis when designing ship control systems. 相似文献
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Takahiro Yajima Hiroyuki Nagahama 《Nonlinear Analysis: Theory, Methods & Applications》2009,71(12):e203
The Rikitake system as nonlinear dynamical systems in geomagnetism can be studied based on the KCC-theory and the unified field theory. Especially, the behavior of the magnetic field of the Rikitake system is represented in the electrical system projected from the electro-mechanical unified system. Then, the KCC-invariants for the electrical and mechanical systems can be obtained. The third invariant as the torsion tensor expresses the aperiodic behavior of the magnetic field. Moreover, as a result of the projection, a protrusion between the mechanical and electrical systems is represented by the Euler-Schouten tensor. This Euler-Schouten tensor and the third invariant consist of the same mutual-inductance. Therefore, the aperiodic behavior of the magnetic field can be characterized by the protrusion between the electrical and mechanical systems. 相似文献