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991.
In this article we discuss the finite element discretization of the two-dimensional, incompressible, and turbulent boundary layers. The formulation of the momentum equation is essentially due to Baker and Soliman [1] with some modifications.The versatility and the accuracy of the method is established by considering several test cases. The predictions are satisfactory and compare favorably with alternative numerical techniques. 相似文献
992.
林卫东 《纯粹数学与应用数学》1995,11(1):104-108
本文对具有状态终端约束、控制受限的非线性连续最优控制问题给出一种新的可实现的离散方法,此方法通过求解非线最小二乘问题避免这类问题离散后出现的不可行现象,文中给出这种做法的理论证明和实现方案。 相似文献
993.
设k,r分别是自然数和非零整数,Jk(n)是Jordan函数.文[3]求出了和式∑n≤xJrk(n)的渐近公式.以E(x;k,r)表示该公式中的误差项,本文研究了E(x;k,r)的算术均值和积分均值 相似文献
994.
Any quadratic spline with coinciding interpolating points and breakpoints can be uniquely determined by one initial condition. We examine how to choose the initial value in positive interpolation by using a norm of the spline. Monotone interpolation is also considered. The results are illuminated by numerical examples and by an application. 相似文献
995.
Martin Hermann 《Journal of Computational and Applied Mathematics》1983,9(1):71-80
A new numerical method is presented to analyze perturbations of bifurcations of the solutions of nonlinear boundary value problems. The perturbations may result from imperfections or other inhomogeneities in the corresponding scientific problem. The nonisolated solutions are calculated in dependence of the perturbation parameter. Therefore, it is possible to determine the singular solution as well as a solution branch through this nonisolated solution simultaneously. Standard procedures of numerical analysis are applicable. 相似文献
996.
This paper presents the integral representations of the displacement and rotation fields of the micropolar continuum, and the regularized integral representations of the traction and couple vector. Thus the boundary integral equations and the boundary integro-differential equations are derived. In addition, the formulation for crack problems is given by both the boundary integral equations and the boundary integro-differential equations. 相似文献
997.
Random walks on lattices. IV. Continuous-time walks and influence of absorbing boundaries 总被引:1,自引:0,他引:1
The general study of random walks on a lattice is developed further with emphasis on continuous-time walks with an asymmetric bias. Continuous time walks are characterized by random pauses between jumps, with a common pausing time distribution(t). An analytic solution in the form of an inverse Laplace transform for P(l, t), the probability of a walker being atl at timet if it started atl
o att=0, is obtained in the presence of completely absorbing boundaries. Numerical results for P(l, t) are presented for characteristically different (t), including one which leads to a non-Gaussian behavior for P(l, t) even for larget. Asymptotic results are obtained for the number of surviving walkers and the mean l showing the effect of the absorption at the boundary.This study was partially supported by ARPA and monitored by ONR(N00014-17-0308). 相似文献
998.
A survey of previous studies on vacuum deposited metal films shows that in high frequency measurements, explicit reference
to the effect of air-exposure is not made. The present work on bismuth films (in-situ and air-exposed) at dc and rf frequencies, carried out mainly to study the air-exposure effect, shows that in-situ
dc and rf and exposed rf all show nearly the same resistivity for thick continuous films. But air-exposed dc film resistances, when compared to in-situ
dc resistances, show that the grain boundary reflection coefficient, R
gin Mayadas-Shatzkes model changes from 0·2 to 0·6. This is shown to be due to the grain boundary oxidation. The result is
substantiated by rf measurements. 相似文献
999.
J. C. Allwright 《Journal of Optimization Theory and Applications》1980,32(3):327-343
The deterministic linear-system, quadratic-cost optimal control problem is considered when the only state information available is a partial linear observation of the initial statex
0. Thus, it is only known that the initial condition belongs to a particular linear variety. A control function is found which is optimal, in the sense (roughly) that (i) it can be computed using available information aboutx
0 and (ii) no other control function which can be found using that information gives lower cost than it does for every initial condition that could have given rise to the information. The optimal control can be found easily from the conventional Riccati equation of optimal control. Applications are considered in the presence of unknown exponential disturbances and to the case with a sequence of partial state observations. 相似文献
1000.
E. Olusegun George Govind S. Mudholkar 《Annals of the Institute of Statistical Mathematics》1981,33(1):125-129
Summary A functional form of the characteristic function of the sample median of three variates is shown to characterize the logistic
distribution. A consequence of this is a characterization of the logistic in terms of the Laplace distribution.
Research sponsored in part by the Air Force Office of Scientific Research, Air Force Systems Command, USAF under Grant No.
AFOSR-77-3360. The United States Govenment is authorized to reproduce and distribute reprints for governmental purposes notwith-standing
any copyright notation hereon. 相似文献