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991.
两同心球间旋转流动类Lorenz方程组的静态分歧 总被引:3,自引:0,他引:3
对同心球间旋转流动的N av ier-S tokes方程谱展开后进行三模态截断,讨论了所得到的类Lorenz型方程组的分歧问题.给出了静态奇异点的条件,并计算出解分支.首先,简要介绍了Lorenz方程组以及用Lorenz截断法讨论非线性问题的意义,其次,推导同心球间旋转流动N av ier-S tokes方程的流函数-涡度形式,最后,讨论同心球间旋转流动的类Lorenz型方程组的分歧问题. 相似文献
992.
In this work,the well-known problem put forward by S N Bernstein in 1930 is studied in a deep step.An operator is constructed by revising double interpolation nodes.It is proved that the operator converges to arbitrary continuous functions uniformly and the convergence order is the best. 相似文献
993.
A new numerical method called high accuracy time and space transform method (TSTM) is introduced to solve the advection–diffusion equation in an unbounded domain. By a spatial transform, the advection–diffusion equation in the unbounded domain Rn is converted to one on the bounded domain [?1, 1]n, and the Laplace transform is applied to eliminate time dependency. The consequent boundary value problem is solved by collocation on Chebyshev points. To face the well‐known computational challenge represented by the numerical inversion of the Laplace transform, Talbot's method is applied, consisting of numerically integrating the Bromwich integral on a special contour by means of trapezoidal or midpoint rules. Numerical experiments illustrate that TSTM has exponential rate in time and space. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
994.
王开弘 《数学的实践与认识》2008,38(12):141-144
通过对q元线性码广义Hamming重量dr(·)的分析,应用支撑重量ωs(C)的性质,再次分析了q元[n,k]线性码广义Griesmer界n≥dr+sum from i=1 to k-r[(q-1)dr/qi(qr-1)]. 相似文献
995.
A. I. Gerasimov V. N. Razzhevaikin 《Computational Mathematics and Mathematical Physics》2008,48(8):1406-1417
Mathematical parasite-host models are generalized to the case when the population members differ in susceptibility and contagiousness, there is an external source of infection, and the model parameters depend periodically (seasonally) on time. The model is proved to have a periodic solution that is unique and exponentially stable for sufficiently small periodic oscillations of the coefficients. 相似文献
996.
一种新的两道工序柔性流水车间排序问题 总被引:1,自引:0,他引:1
本文针对F_2(p),h11.1|m_1=1,m_2=μ≥2|C_(max)这一问题给出了几种近似算法,并对每种近似算法进行了最坏情形分析,给出了最坏情形界. 相似文献
997.
This paper is concerned with optimal harvesting policy for an age-dependent n-dimensional food chain model. The existence and uniqueness of non-negative solution of the system are proved using the fixed point theorem. By Mazur's theorem, the existence of optimal control strategy is demonstrated and optimality conditions derived by means of normal cone. 相似文献
998.
在连续时间情形、不考虑交易费用、市场无摩擦假设,以及套期保值准则等条件下,考察了参数随机的证券投资组合中加入未定权益类衍生品形成的最优动态投资策略(u*(t)),并给出了该投资组合的最优模型所对应的黎卡提(Riccati)方程的解的存在性证明. 相似文献
999.
Dong Han Kim Kyewon Koh Park 《Proceedings of the American Mathematical Society》2008,136(11):3941-3951
If an ergodic system has positive entropy, then the Shannon-McMillan-Breiman theorem provides a relationship between the entropy and the size of an atom of the iterated partition. The system also has Ornstein-Weiss' first return time property, which offers a method of computing the entropy via an orbit. We consider irrational rotations which are the simplest model of zero entropy. We prove that almost every irrational rotation has the analogous properties if properly normalized. However there are some irrational rotations that exhibit different behavior.
1000.
This paper addresses the problem of scheduling cascaded ‘blocked out’ continuous processing units separated by finite capacity
storage tanks. The raw materials for the product lines arrive simultaneously on the input side of the first unit. But every
unit can process only one product line at a time, thus giving rise to the possibility of spillage of raw material due to limited
storage capacity. The need to process multiple product lines and the added constraint of multiple intermediate upliftment
dates aggravate the problem. This problem is quite common in petrochemical industry. The paper provides a MINLP (Mixed Integer
Non-Linear Programming) formulation of the problem. However, for any realistic scheduling horizon, the size of the problem
is too large to be solved by standard packages. We have proposed a depth first branch and bound algorithm, guided by heuristics,
to help planners in tackling the problem. The suggested algorithm could output near optimal solutions for scheduling horizons
of 30 time periods when applied to real life situations involving 3 units and 3 product lines.
Preliminary version of the paper appeared in the proceedings of MISTA, 2005. 相似文献