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排序方式: 共有57条查询结果,搜索用时 46 毫秒
1.
三维动态失速模型研究   总被引:3,自引:0,他引:3  
研究了一个等速上扬的三维直机翼的动态失速过程,并对失速现象的产生机理及发展过程给出定性的分析.通过与二维情况的对比,重点考察了三维情况下动态失速涡的产生、发展及在物面上的移动对失速性能的影响.在加深了对三维动态失速原理理解的基础上,建立了三维的动态失速模型,能较好地模拟三维动态失速下机翼的气动性能.  相似文献
2.
Banach空间中一类集值度量广义逆的连续选择   总被引:1,自引:1,他引:0  
讨论Banach空间中余一维闭值域有界线性算子的集值度量广义逆问题,在一定的条件下,给出该集值度量广义逆的连续单值选择的具体表达式,部分解决了M.Z.Nashed与G.F.Votruba提出的研究问题.  相似文献
3.
在风险模型中一类重尾随机和的大偏差   总被引:1,自引:0,他引:1  
4.
集装箱翻箱问题的模型分析及算法   总被引:1,自引:0,他引:1  
董琳  刘庆敏  王超  王晓  吕长虹 《经济数学》2006,23(2):181-186
针对实际生产中集装箱的装船问题,预翻箱是提高装船准确率和装船效率的一个有效方法.本文利用图论知识构建预翻的数学模型,并用加以限制的广度搜索算法计算出翻箱的最少步骤.  相似文献
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The soft set theory, originally proposed by Molodtsov, can be used as a general mathematical tool for dealing with uncertainty. The interval-valued intuitionistic fuzzy soft set is a combination of an interval-valued intuitionistic fuzzy set and a soft set. The aim of this paper is to investigate the decision making based on interval-valued intuitionistic fuzzy soft sets. By means of level soft sets, we develop an adjustable approach to interval-valued intuitionistic fuzzy soft sets based decision making and some numerical examples are provided to illustrate the developed approach. Furthermore, we also define the concept of the weighted interval-valued intuitionistic fuzzy soft set and apply it to decision making.  相似文献
7.
In this paper we investigate the non-autonomous elliptic equations \(-\Delta u = |x|^{\alpha } u_{+}^{p}\) in \( \mathbb{R }^{N}\) and in \( \mathbb{R }_+^{N}\) with the Dirichlet boundary condition, with \(N \ge 2\) , \(p>1\) and \(\alpha >-2\) . We consider the weak solutions with finite Morse index and obtain some classification results.  相似文献
8.
Although different kinds of evolutionary algorithms (EAs) have been designed and achieved great success on many optimization problems, they are usually limited to some small-scale problems, e.g. with less than 100 decision variables, which may be quite small comparing to the requirements of real-world applications. Therefore, scaling EAs to large size problems have attracted more and more interest. Conventional EAs mimic the seemingly random natural processes by which species evolve. These evolution processes are slow or inefficient. Now, genetic engineering has enabled man to increase both the yields and quality of some crops fast by modifying some part of their genome precisely. In this paper, inspired by the ideas of the genetic engineering, we designed a local selection operator by decomposing the high-dimensional problem into some subcomponents and assigning a local fitness function to evaluate each subcomponent. Then a new differential evolution (DE) is proposed by inserting the local selection operator into the framework of DE. Numerical experiments were carried out to evaluate the performance of the new algorithm on a large number of benchmark functions. The results show that the new algorithm is effective and efficient for high-dimensional optimization.  相似文献
9.
In this paper, we prove the global existence of weak solutions to the full compressible Navier-Stokes equations in the domain exterior to a ball in R n (n=2,3) and with spherically symmetric data.  相似文献
10.
In this paper shunting inhibitory cellular neural networks (SICNNs) with time-varying and continuously distributed delays are considered on time scale T. Without assuming the global Lipschitz conditions of activation functions, some new sufficient conditions for the existence and asymptotic stability of the almost periodic solutions are established on time scales. Two numerical examples are given to illustrate our feasible results.  相似文献
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