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951.
Cha Kewen Li Chuanzhong 《大学数学》1998,(2)
本文首先建立了按年龄分组的可再生资源,各年龄组数量应满足的向量微分模型.然后利用所建模型成功地解决了CMCM96A题中的问题2. 相似文献
952.
Vijay GUPTA 《数学学报(英文版)》2007,23(8):1457-1462
In this paper, we study the rate of convergence for functions of bounded variation for the recently introduced Bzier variant of the Meyer-Knig-Zeller-Durrmeyer operators. 相似文献
953.
J. Hashemi N. Chandrashekar T. Jang F. Karpat M. Oseto S. Ekwaro-Osire SEM Member 《Experimental Mechanics》2007,47(3):347-354
In the United States, an estimated 100,000 anterior cruciate ligament (ACL) injuries occur every year. Despite decades of
research, to this date, the mechanism or mechanisms of non-contact ACL injuries are not well understood. This is primarily
because trials cannot be conducted on live subjects to understand the injury mechanism, and it is difficult to instrument
a live human knee to measure the response of tissues during dynamic activities. In this paper, we present a dynamic knee injury
simulator capable of in-vitro modeling of the ACL injury during jump-landing activity. This system was used to simulate jump-landing on cadaveric knees
and to successfully test which conditions would result in isolated ACL injury. A restricted flexion of the hip (a hip that
flexes minimally or not at all during landing), combined with low quadriceps and hamstring force levels during landing were
found to be conducive to ACL injury. Elevated levels of quadriceps force prevented the injury from occurring even under restricted
hip flexion conditions. The measured strain rates in the ACL tissue during injury causing activities were over 250%/s. 相似文献
954.
Response probability density functions of strongly non-linear systems by the path integration method
The paper discusses challenges in numerical analysis and numerical/analytical results for strongly non-linear systems—systems with “signum”-type non-linearities. Such non-linearities are implemented for instantaneous variations of the systems’ parameters, to reduce their mean energy response when subjected to random excitations. Numerical results for displacement and velocity response probability density functions (PDFs), energy response PDFs and various order moments are obtained by the path integration technique. Attention is also given to evaluation of mean upcrossing rate, related to the system's half period, via Rice's formula informally applied to discontinuous response PDFs. 相似文献
955.
956.
Hsien-Chung Wu 《Applications of Mathematics》2007,52(1):1-23
The procedures for constructing a fuzzy number and a fuzzy-valued function from a family of closed intervals and two families
of real-valued functions, respectively, are proposed in this paper. The constructive methodology follows from the form of
the well-known “Resolution Identity” (decomposition theorem) in fuzzy sets theory. The fuzzy-valued measure is also proposed
by introducing the notion of convergence for a sequence of fuzzy numbers. Under this setting, we develop the fuzzy-valued
integral of fuzzy-valued function with respect to fuzzy-valued measure. Finally, we provide a Dominated Convergence Theorem
for fuzzy-valued integrals. 相似文献
957.
对一般目标函数极小化问题的拟牛顿法及其全局收敛性的研究,已经成为拟牛顿法理论中最基本的开问题之一.本文对这个问题做了进一步的研究,对无约束优化问题提出一类新的广义拟牛顿算法,并结合Goldstein线搜索证明了算法对一般非凸目标函数极小化问题的全局收敛性. 相似文献
958.
设Ω=[-πxπ,-πyπ],C(Ω)表示关于x,y均以2π为周期的连续函数空间.若f(x,y)∈C(Ω),取结点组为(xk,yl)=(2k+2n 1)π,(2l 2+m 1)πk=0,1,2,…,2n,l=0,1,2,…,2m,则我们获得一个二元三角插值多项式Cn,m(f;x,y)=M1N∑k=2n0∑l=2m0f(xk,yl).1+2∑nα=1cosα(x-xk)+2∑mβ=1cosβ(y-yl)+4∑nα=1∑mβ=1cosα(x-xk)cosβ(y-yl)其中M=2m+1,N=2n+1.为改进其收敛性,本文构造一个新的因子ρα,β,使得带有该因子ρα,β的二元三角插值多项式Ln,m(f;x,y)可以在全平面上一致地收敛到每个连续的f(x,y),且具有最佳逼近阶. 相似文献
959.
In this paper, we are concerned with epiconvergent sequences of nonsmooth functions. From a general principle of upper set
convergence of set-valued maps we derive stability results for various objects in generalized differentiability. In particular,
we establish stability results for the Clarke generalized gradient of locally Lipschitz functions, respectively for the generalized
Hessian of C
1,1 functions.
相似文献
960.
Arindam Roy Manas Kumar Maiti Samarjit Kar Manoranjan Maiti 《Mathematical and Computer Modelling》2007,46(11-12):1419-1433
An inventory model for a deteriorating item with stock dependent demand is developed under two storage facilities over a random planning horizon, which is assumed to follow exponential distribution with known parameter. For crisp deterioration rate, the expected profit is derived and maximized via genetic algorithm (GA). On the other hand, when deterioration rate is imprecise then optimistic/pessimistic equivalent of fuzzy objective function is obtained using possibility/necessity measure of fuzzy event. Fuzzy simulation process is proposed to maximize the optimistic/pessimistic return and finally fuzzy simulation-based GA is developed to solve the model. The models are illustrated with some numerical data. Sensitivity analyses on expected profit function with respect to distribution parameter λ and confidence levels α1 and α2 are also presented. 相似文献