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1.
We introduce some ways to compute the lower and upper bounds of the Laplace eigenvalue problem.By using the special nonconforming finite elements,i.e.,enriched Crouzeix-Raviart element and extended Q1ro t,we get the lower bound of the eigenvalue.Additionally,we use conforming finite elements to do the postprocessing to get the upper bound of the eigenvalue,which only needs to solve the corresponding source problems and a small eigenvalue problem if higher order postprocessing method is implemented.Thus,we can obtain the lower and upper bounds of the eigenvalues simultaneously by solving eigenvalue problem only once.Some numerical results are also presented to demonstrate our theoretical analysis.  相似文献   

2.
Suppose F0 is an arbitrary triangle and F is a kind of Sierpinski carpet generated by F0.We construct a projection mapping to obtain the lower bound of the Hausdorff measure of F ;meanwhile the upper bound of the Hausdorff measure of F is calculated by the general covering.  相似文献   

3.
Xie  Rui Jun  Yuan  Rong  Yang  Zhi Hui 《数学学报(英文版)》2020,36(1):77-92
This paper is concerned with the travelling wavefronts of a nonlocal dispersal cooperation model with harvesting and state-dependent delay,which is assumed to be an increasing function of the population density with lower and upper bound.Especially,state-dependent delay is introduced into a nonlocal reaction-diffusion model.The conditions of Schauder's fixed point theorem are proved by constructing a reasonable set of functionsΓ(see Section 2)and a pair of upper-lower solutions,so the existence of traveling wavefronts is established.The present study is continuation of a previous work that highlights the Laplacian diffusion.  相似文献   

4.
In this article,we analyze the lower bound of the divisibility of families of exponential sums for binomials over prime field.An upper bound is given for the lower bound,and,it is related to permutation polynomials.  相似文献   

5.
This paper considers adaptive point-wise estimations of density functions in GARCH-type model under the local Holder condition by wavelet methods.A point-wise lower bound estimation of that model is first investigated;then we provide a linear wavelet estimate to obtain the optimal convergence rate,which means that the convergence rate coincides with the lower bound.The non-linear wavelet estimator is introduced for adaptivity,although it is nearly-optimal.However,the non-linear wavelet one depends on an upper bound of the smoothness index of unknown functions,we finally discuss a data driven version without any assumptions on the estimated functions.  相似文献   

6.
This paper discusses the large deviation for the empirical field of a symmetricmeasure.The lower bound of the large deviation is obtained by extending the classcal Shannon-McMillan theorem. The upper bound is established by means of Legendre transformation and the minimax theorem.  相似文献   

7.
Two residual-based a posteriori error estimators of the nonconforming Crouzeix-Raviart element are derived for elliptic problems with Dirac delta source terms.One estimator is shown to be reliable and efficient,which yields global upper and lower bounds for the error in piecewise W1,p seminorm.The other one is proved to give a global upper bound of the error in Lp-norm.By taking the two estimators as refinement indicators,adaptive algorithms are suggested,which are experimentally shown to attain optimal convergence orders.  相似文献   

8.
In this work, we obtain the global existence and uniqueness of classical solu-tions to a viscous liquid-gas two-phase model with mass-dependent viscosity and vacuum in one dimension, where the initial vacuum is allowed. We get the upper and lower bounds of gas and liquid masses n and m by the continuity methods which we use to study the compressible Navier-Stokes equations.  相似文献   

9.
ASYMPTOTIC BEHAVIOR OF THE DRIFT-DIFFUSION SEMICONDUCTOR EQUATIONS   总被引:4,自引:1,他引:3  
This paper is devoted to the long time behavior for the Drift-diffusion semi-conductor equations. It is proved that the dynamical system has a compact, connected and maximal attractor when the mobilities are constants and generation-recombination term is the Auger model; as well as the semigroup S(t) defined by the solutions map is differential. Moreover the upper bound of Hausdorff dimension for the attractor is given.  相似文献   

10.
Special ideals in partial abelian monoids   总被引:1,自引:0,他引:1  
Under some conditions, the special congruences of partial abelian monoid are those induced by the special ideals, and a class of special ideals of partial abelian monoid has some upper and lower bound properties.  相似文献   

11.
本文研究带常利率的离散时间的风险模型,得出了保险公司最终破产概率的一个近似解.给出了估计破产概率的上下界的表达式,并得到近似解的误差估计值.最后将结果应用到当保费服从指数分布这一特殊情况.  相似文献   

12.
邓丽  谭激扬 《经济数学》2014,(4):102-106
研究复合二项对偶模型的最优分红问题,通过分析HJB方程得到了最优分红策略和相应的最优值函数之间的关系以及最优值函数的简单计算方法.通过讨论最优红利策略的一些性质得到了最优值函数的可无限逼近的上界和下界.  相似文献   

13.
带常利率的双Poisson模型的破产概率   总被引:1,自引:0,他引:1  
本文在保费的收取和理赔都为复合Poisson过程的盈余过程的基础上,考虑盈余产生利息的双Pois-son模型,在保费收取量和理赔量都取整数值时,我们运用转移概率推导出了破产概率的近似计算公式及误差估计式,并且得到了破产概率的一个上界和一个下界.  相似文献   

14.
讨论一个任意正整数保费率的复合二项模型.获得了这个模型的Gerber-Shiu 罚金函数值满足的线性方程、一个上界、一个下界.  相似文献   

15.
Although Bermudan options are routinely priced by simulation and least-squares methods using lower and dual upper bounds, the latter are hardly optimized. In this paper, we optimize recursive upper bounds, which are more tractable than the original/nonrecursive ones, and derive two new results: (1) An upper bound based on (a martingale that depends on) stopping times is independent of the next-stage exercise decision and hence cannot be optimized. Instead, we optimize the recursive lower bound, and use its optimal recursive policy to evaluate the upper bound as well. (2) Less time-intensive upper bounds that are based on a continuation-value function only need this function in the continuation region, where this continuation value is less nonlinear and easier to fit (than in the entire support). In the numerical exercise, both upper bounds improve over state-of-the-art methods (including standard least-squares and pathwise optimization). Specifically, the very small gap between the lower and the upper bounds derived in (1) implies the recursive policy and the associated martingale are near optimal, so that these two specific lower/upper bounds are hard to improve, yet the upper bound is tighter than the lower bound.  相似文献   

16.
线性模型参数估计的一种新的相对效率   总被引:2,自引:0,他引:2  
本文对线性模型的最小二乘估计(LSE)与最佳线性无偏估计(BLUE)提出了一种新的相对效率并给出了新的相对效率的上、下界,最后还讨论了新的相对效率与已有的几种相对效率的关系。  相似文献   

17.
基于多重工作休假的成批到达离散时间排队的性能分析   总被引:2,自引:0,他引:2  
研究了一个成批到达的离散时间 Geom$^{[X]}$/Geom/1 多重工作休假排队. 首先,建立了模型的二维马尔可夫链,利用矩阵分析的方法, 导出了稳态队长复杂的概率母函数. 其次, 为了展示此模型与经典无休假Geom$^{[X]}$/Geom/1排队的联系, 给出稳态队长的随机分解结果. 尤其重要的是,发现了条件负二项分布的双参数加法定理, 利用这些结论,得到了矩母函数序下的稳态等待时间的上下界. 进一步,求出了平均队长和平均等待时间的上下界. 最后,提出一些数值例子以验证结论.  相似文献   

18.
In this paper we consider a SMP fluid model when the so-called BSNE has no solution and kernel distributions of input environment processes are not heavy-tailed. We prove that in this case we still can find the upper exponential bound for the buffer overflow probability and give the example showing that the lower bound is impossible in general.  相似文献   

19.
回归系数的混合估计与最小二乘估计的一个新的相对效率   总被引:2,自引:0,他引:2  
本文对具有附加信息的线性回归模型中的混合估计与最小二乘估计给出了一种新的相对效率,研究了新的相对效率与其它几种相对效率的关系,得出了新的相对效率的上、下界.  相似文献   

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