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1.
本文研究含无穷拉普拉斯算子的渗流问题.运用改进的Bernstein方法和光滑逼近,分别建立了该问题严格正粘性解和非负粘性解关于空间变量的李普希兹估计.  相似文献   

2.
当底空间紧时, 初始函数为连续函数的Lax-Oleinik型粘性解是局部半凹的,所以是相应的Hamilton-Jacobi\ (以下简称为H-J) 演化方程(简称为接触H-J方程)的粘性解.当底空间非紧时, 对于H-J方程和接触H-J方程, 其Lax-Oleinik型解的下确界未必能取到.文章将探讨在非紧空间上, 折现H-J方程粘性解有限性的条件, 并给出了在此假设下粘性解的表达式.  相似文献   

3.
研究了一种人工和物理耗散机制下的离散熵相容格式,探讨数值粘性和物理粘性的大小以及它们所起的作用.所得结论是:在激波捕捉的过程中,粘性系数越大,则无需加入人工粘性项;粘性系数较小时,除了物理粘性项,还需要加入人工粘性项来得到熵相容格式.首先研究了一维粘性Burgers方程离散熵相容格式,再将其推广至Navier-Stokes方程.数值算例采用空间半离散格式,并结合显式三步三阶Runge-Kutta(RK3)方法进行时间推进.这两类方程的数值结果表明,最终选取的熵相容格式能够准确地捕捉到激波.  相似文献   

4.
使用粘性近似方法研究了一类高阶Camasa-Holm型方程.推出了该类方程粘性解的高阶可积性估计及其空间导数的上界估计,从而证明了该类方程整体弱解的存在性.  相似文献   

5.
在具有一致Gateaux可微范数的Banach空间中,研究了一个逼近非扩张映射不动点的粘性逼近方法,运用Banach极限推导了该逼近方法收敛的充分条件,并通过对该粘性逼近方法的修正逐步减少了收敛分析中的限制条件.  相似文献   

6.
本文研究双曲松弛粘性Cahn-Hilliard方程的混合有限元数值算法.求解具有双曲松弛项和双阱势能的粘性Cahn-Hilliard方程时,在时间上采用一阶半隐格式进行离散,在空间上采用混合有限元方法进行离散.通过严格的理论分析证明了数值格式的无条件能量稳定性和误差估计,并利用数值实验验证了该方法的有效性.  相似文献   

7.
孔花  冯民富  覃燕梅 《计算数学》2013,35(1):99-112
本文结合子格粘性法的思想,空间采用非协调Crouzeix-Raviart元逼近,时间采用Crank-Nicolson差分离散,对非定常线性化Navier-Stokes方程建立了全离散的子格粘性非协调有限元格式.对稳定性和误差估计作出了详细的分析, 得出了最优的误差估计.最后, 通过数值算例进一步验证了该方法的稳定性和收敛性.  相似文献   

8.
基于压力投影和梯形外推公式,对速度/压力空间采用等阶多项式逼近,针对高Rteynoldslt数下的瞬态Navier-stokes方程提出了一种新的全离散粘性稳定化方法.该方法不仅绕开了inf-sup条件的限制,克服了高Reynolds数下对流占优造成的不稳定性,而且在每一时间步上,只需要进行线性计算,从而减少了计算量.给出了稳定性证明,并得出了与粘性系数一致的误差估计.理论和数值结果表明该方法具有二阶精度.  相似文献   

9.
本文对粘性不可压缩Navier-Stokes方程提出了一种等阶稳定化亏量校正有限元法.将通常的压力投影稳定化方法与亏量校正思想相结合,建立了一种稳定的有限元格式,绕开了inf-sup条件的限制,并且克服了当粘性系数很小时造成的不稳定性.对速度/压力采用等阶多项式空间,证明了解的存在唯一性,给出了误差估计.误差估计的结果表明,每校正一步误差的精度提高一阶.  相似文献   

10.
考虑图像修复中BSCB方程和变形的BSCB方程组的粘性问题.运用半群理论,得到粘性BSCB方程光滑解的存在唯一性.此外,利用粘性消失方法还得到:当粘性系数ν→0时,粘性变形的BSCB方程组的解在经典意义下收敛到变形的BSCB方程组的解.  相似文献   

11.
A new numerical differential filter is built to estimate the numerical differential for a chaotic time series and then a differential phase space for the chaotic time series is reconstructed. Correlation dimensions, Lyapunov exponents and forecasting are discussed for the chaotic time series on the reconstructed differential phase space and on the delay phase space, respectively. Comparison results show that the numerical results on the differential phase space are better than that on the delay phase space.  相似文献   

12.
A general model of a pure exchange differential information economy is studied. In this economic model, the space of states of nature is a complete probability measure space, the space of agents is a finite measure space, and the commodity space is the Euclidean space. Under some appropriate and standard assumptions on agents' characteristics, results on continuity and measurability of the aggregate preferred correspondence similar to that of Aumann [8] are established. These results together with other techniques are then employed to prove the existence of a maximin rational expectations equilibrium (maximin REE) of the economic model.  相似文献   

13.
引入了一类BaBesov空间,由此刻画了Bernstein-Kantorovi(?)算子在Ba范数下的饱和类,在Orlicz空间及Lp空间中的相应结论作为Ba空间理论的应用而给出。  相似文献   

14.
Summary Approximate Markov process defined on the extended sample space plays an important role in the theory of Dirichlet Space. In this paper, stochastic analysis is studied on the extended sample space including the Stratonovitch integral, Ito's formula, etc. and a tightness and continuity results about excursion laws of the processes associated to a sequence of Dirichlet spaces is obtained by following an idea of Lyons and Zheng. These results are applied back to the standard sample space, which improve a few results about the additive functionals and also enable us to obtain the Lyons and Zheng's tightness and continuity results in the situation where the processes may blow up and have killings. Connections between the Stratonovitch integrals on the extended sample space and that defined by Nakao with respect to a function in the Dirichlet space is made.  相似文献   

15.
K-非常凸空间   总被引:1,自引:0,他引:1  
本文引入了一种新的K凸空间K-非常凸空间,及其对偶空间K-非常光滑空间,它们分别是非常凸空间和非常光滑空间的推广但又严格弱于非常凸空间和非常光滑空间,因此它们又有许多独特的性质.本文讨论了它们的一些特性及与其它K凸性和K光滑性的关系,推广了[3]、[6]、[7]、[8]中的一些结果.  相似文献   

16.
柏灵  王克 《东北数学》2005,21(1):95-104
In this article, we consider compound matrices and compound operator equations in a Hilbert space. First, we recall some concepts and main results introduced by Muldowney and by Roger Temam. After that we establish the rule of compound matrices in a Hilbert space, and obtain the expression of solution to a compound operator equation by using the method of operator semigroup. Our brief results generalize the corresponding results in a finite space.  相似文献   

17.
A model and an algorithm are proposed for the simultaneous optimal selection among a given set of products of the assortment of products to be sold in a supermarket and the allocation of shelf space to these products. The model takes into account the space elasticity of the sales as well as the constraints that any chosen product must receive a minimum shelf space and that the shelf space allocated to each product must be equal to an integer number of facings.Computational results are presented, including a comparison with the results given by several rules for space allocation currently used. Some marketing implications are discussed.  相似文献   

18.
We establish optimization results for set-valued mappings, with the image space given by a topological vector space partially ordered by a cone. Moreover, we obtain stability results relative to parametrized optimization problems. We use a weak semicontinuity concept related to the order structure of the image space and show how compactness assumptions used in previous papers can be lightened.  相似文献   

19.
利用能量不等式和一些临界空间中的不等式,在Morrey—Campanato空间获得了两个只涉及水平速度场的正则性准则,改进了一些已有的结果.  相似文献   

20.
We characterize functions in Morrey space by p-Carleson measures. We then reveal a simple relation between Q space and Morrey space, that is Q space can be viewed as a fractional integration of the Morrey space. Therefore, many results for Morrey space can be translated onto Q space. For example, we show that Q space is a dual space by identifying its predual.  相似文献   

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