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1.
严骏  甘燕 《运筹与管理》2003,12(6):118-122
本分析敏捷虚拟企业联盟企业选择的特点,基于LST,提出了敏捷虚拟企业联盟企业选择控制系统结构及联盟企业的多准则选择方法,提出了基于评判委员会的隶属度判定方法,给出了敏捷虚拟企jE联盟企业选择仿真示例,最后,对本的研究意义进行了总结。  相似文献   

2.
不确定意义下的路径选择研究   总被引:4,自引:0,他引:4  
本文利用不确定性对策理论,考虑了出行者的主观理性判断和信息对出行路径选择的影响,研究了出行者在不确定意义下的路径选择行为,说明了信息在路径选择过程中的重要性。  相似文献   

3.
基于DS/AHP的供应商选择方法   总被引:4,自引:0,他引:4  
梁昌勇  陈增明  丁勇 《运筹与管理》2005,14(6):33-38,56
供应商选择方法有很多种,在众多的方法中层次分析法以能够将定性指标定量化而被广泛应用于供应商选择决策中。考虑到供应商选择问题中包含有很多的不确定性而证据理论在处理不确定问题又有着独特的优点,因此本文采用了一种由层次分析法和证据理论结合而产生的DS/AHP决策方法,并将其应用于供应商选择决策问题中,该方法综合了层次分析法和证据理论的优点,可以更科学的进行供应商选择决策,最后通过一个例子说明这种方法在供应商选择中的应用。  相似文献   

4.
戴阔斌  陈建华 《数学杂志》2005,25(6):659-663
本文研究了大整数因子分解中的二次筛法,提出了算法选择,参数选择,硬件选取和过程控制上的优化途径,直接影响RSA密码系统,推动信息安全的发展。  相似文献   

5.
团队成员选择的模型及算法   总被引:6,自引:1,他引:5  
本针对组织中组建团队或重组现有团队时的成员选择问题,提出了反映团队成员之间、成员和团队之间关系的群体效用模型,并根据此模型进行团队成员的选择,从而把团队成员选择问题转化为一个组合优化问题。证明了基于群体效用模型进行团队成员选择的问题是NP-hard问题,并且提出了基于ORASP技术和禁忌算法的启发式算法,最后给出了算例。  相似文献   

6.
疏散路径选择是紧急疏散中的重要问题,为了减小疏散人在紧急疏散过程中由于路径选择错误带来的损失,提出一对起讫点间最优抗出错路径选择模型。给出路径出错系数的定义,用以度量疏散人路径选择错误带来的疏散效率损失,并且设计了求解最优抗出错路径的DAE算法,证明该算法的时间复杂度为O( mn2)。结果表明,选择最优抗出错路径作为疏散路径,能够有效地抵抗由于疏散人路径选择错误带来的损失,对提高突发事件下的疏散效率具有实际意义。  相似文献   

7.
再论线性模型自变元选择的BIC方法相容性条件   总被引:2,自引:0,他引:2  
在许多情况下,对线性回归模型我们感兴趣于选择足够多的重要预测变量,本文指出了1中对著名的BIC准则变量选择方法强相合性证明的错误,并重新给出了一组强相全性条件。在这组条件下,我们也证明了BIC选择方法是强相合的,这组新的条件既容易验证又应用广泛。  相似文献   

8.
根据生产任务选择加工设备进行制造资源重组是实现可重构制造系统的关键问题之一,由于设备的选择涉及到多种因素,既有定量指标,又有定性指标,传统的依靠人工经验的方法显得力不从心。本文首先结合实际情况,提出了一套设备选择评价体系,通过对模糊判断矩阵采用最小对数二乘法确定各评价因素的权重系数,针对定性指标和定量指标采用不同的方法确定其性能指标值,通过模糊积分对评判指标进行综合评判,最后进行了实例研究。所提出的方法有效地简化了决策过程,为可重构制造系统设备选择提供了一套行之有效的方法。  相似文献   

9.
研究了一类带有单稳非线性项的三物种竞争系统行波解最小波速的速度选择.首先利用比较方法,通过构造适当的上下解,建立了最小波速的速度选择机制.然后证明了物种的竞争系数关于速度选择的阈值结果,并得到了阈值的估计.最后借助数值模拟说明所得结果推广了已有文献的相关工作.  相似文献   

10.
虚拟企业合作伙伴选择的综合评判方法   总被引:8,自引:0,他引:8  
在虚拟企业合作伙伴选择的基本原则及合作伙伴选择步骤研究的基础上,提出了一种新的虚拟企业合作伙伴选择的方法,将所有候选伙伴按其投标的核心能力类型进行分类并组成虚拟企业组合方案,根据总成本最低原则、敏捷性原则和风险最小化原则,对虚拟企业组合进行综合评判。  相似文献   

11.
Conclusions As the result of a change in the deformation characteristics of the elementary layers, which is asymmetric with respect to the middle plane of the composite, and caused by imperfections of technical character, aging, the effect of temperature, moisture content, corrosive media, and other factors, the balancing of the laminated polymeric composites is disturbed. Formulas were obtained for determining all the pliability and rigidity matrix components of a nonbalanced monoclinic composite from known deformation characteristics, volume, and order of packing of the elementary layers.Institute of Wood Cellulose Chemistry, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 6, pp. 1030–1035, November–December, 1976.  相似文献   

12.
Based on the study of the kinetics of deformation or rigidity, of the rise in temperature, and of the fracture surfaces, the article describes the mechanism of failure of plastics. It as found that in a cyclically loaded solid there occur two processes: strengthening and loss of strength. The main factors affecting strengthening in fatigue were discovered. Among them are the structure of the material, the degree of crystallinity, the load level, conditions of deformation, etc. The kinetics of rigidity can yield the most accurate information providing an idea of the process of fatigue failure of plastics.Paper read at the 9th International Conference on the Mechanics of Composite Materials, Riga, October, 1995.Kaunas Technological University, Lithuania. Translated from Mekhanika Kompozitnykh Materialov, Vol. 32, No. 2, pp. 279–285, March–April, 1996.  相似文献   

13.
Surface interaction among non-overlapping bulk-fluid and porous-medium bodies occurs in different situations, e. g., the interaction of blood with a blood vessel wall, a body of water with an earth dam structure, or acoustic waves with acoustic panels used in soundproofing. These are multi-field phenomena, comprising various surface- and volume-coupling mechanisms that should be reflected in the corresponding mathematical models. These models, together with appropriate initial and boundary values, assemble a coupled problem, the solution of which reveals the behaviour of the system under external excitations. The solution is commonly done numerically, following a monolithic or a decoupled approach. Here, the focus is on the latter. To design an efficient decoupled scheme, different types of coupling within the problem are addressed. These are the volume coupling between the degrees of freedom (DOF) within each subdomain, and the surface coupling between the DOF on the common boundaries. In particular, the latter constrains the feasible space of the solution of the problem. In this regard, local Lagrange multipliers (LLM) are employed to reformulate the problem in an unconstrained form. Unlike other domain decomposition methods which are based on using global Lagrange multipliers, the LLM method yields a complete separation of the subdomains and, consequently, facilitates parallel solution of the sub-problems. Moreover, within the subdomains, the penalty method is used to decouple pressure from other DOF. This procedure, on the one hand, reduces the size of the problem that should be solved at the interface and, on the other hand, removes the burden of using mixed finite elements within the subsystems. In the next step, the stability behaviour of the resulting staggered approach is analysed, and the unconditional stability of the method is established. Finally, the method is employed to solve a benchmark example, and using the numerical results, the reliability of the outcomes of the stability analysis is investigated. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

14.
Mathematical writers, above all, Euclid, tend to present their theorems as decontextualized, abstract propositions, which has become the standard modus of textual presentation in theoretical mathematics. Mathematical commentators, however, provide their readers with personal names and historical facts in order to elucidate problems, provide contexts of discovery, or construct doxographies, among other things. Modern readers have used such information for the construction of histories of science. When we look at these passages, however, we see that personal names and information about mathematicians of the past can serve quite a range of different objectives, such as the strategic self-positioning of the commentator vis-à-vis the past or present of mathematics, the education of the reader, mathematical or moral, the construction of the history of the field, etc. Not only does the commentator present a persona of himself to the reader, he can also turn colleagues and predecessors into personae. This paper attempts to elucidate the practice, by offering four examples of such plays of and with personae, in Pappus, Eutocius, al-Nayrīzī, and Proclus.  相似文献   

15.
X-ray structural studies on the changes in oriented polyethylene fibers during torsion at large and small angles showed that the crystallites undergo shear deformation, and the angle x between the axes of the macromolecules and the upper (lower) faces of the crystallites deviates appreciably from a right angle. As a result of torsion of the fibers, an axial texture of the fibrill is formed, inside which the crystallites are skewed, while the c axes of the crystallites are inclined to the texture axis. The nature of the more specific changes in the structure depends on the ratio between the temperatures of the preliminary orientational drawing of the samples, and the subsequent torsion.The V. I. Lenin Tadzhik State University, Dushanbe, Institute of Macromolecular Compounds, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 1, pp. 160–162, January–February, 1974.  相似文献   

16.
一维反应扩散方程中的行波波速及行波解   总被引:1,自引:0,他引:1  
通过Painlev啨分析,详细研究了一类一维化学反应扩散方程中的行波解及波速。分别给出了当歼灭项的指数大于创造项的指数及创造项的指数大于歼灭项的指数时,这两种情形下的波速及行波解的显式表示。此外,还给出了一类常见激励介质中的波速及平面波解在薄的边界层内的公式。  相似文献   

17.
The contributions to the philosophy and history of mathematics of one of the most eminent contemporary mathematicians, A. N. Kolmogorov, are analyzed. Although these contributions are not numerous, they contain discussions of the gradual generalization of the subject of mathematics, a partition of the development of mathematics—in particular, of the theory of probability—into periods, and, also, an evaluation of the works of a number of great savants, such as Newton, Lobatchevsky, etc.  相似文献   

18.
《Journal of Complexity》2000,16(1):110-180
We first review the basic properties of the well known classes of Toeplitz, Hankel, Vandermonde, and other related structured matrices and reexamine their correlation to operations with univariate polynomials. Then we define some natural extensions of such classes of matrices based on their correlation to multivariate polynomials. We describe the correlation in terms of the associated operators of multiplication in the polynomial ring and its dual space, which allows us to generalize these structures to the multivariate case. Multivariate Toeplitz, Hankel, and Vandermonde matrices, Bezoutians, algebraic residues, and relations between them are studied. Finally, we show some applications of this study to rootfinding problems for a system of multivariate polynomial equations, where the dual space, algebraic residues, Bezoutians, and other structured matrices play an important role. The developed techniques enable us to obtain a better insight into the major problems of multivariate polynomial computations and to improve substantially the known techniques of the study of these problems. In particular, we simplify and/or generalize the known reduction of the multivariate polynomial systems to the matrix eigenproblem, the derivation of the Bézout and Bernshtein bounds on the number of the roots, and the construction of multiplication tables. From the algorithmic and computational complexity point, we yield acceleration by one order of magnitude of the known methods for some fundamental problems of solving multivariate polynomial systems of equations.  相似文献   

19.
随着金融业全方位开放,国有商业银行已成为国家经济命脉的核心,其竞争力强弱关系着国家经济的繁荣与衰退。本文基于模糊FNN-ELECTRE方法建立国有商业银行竞争力评价模型,以因素神经网络理论(FNN)与ELECTRE融合方法为基础,以现有商业银行竞争力评价指标为着眼,把国有商业银行竞争力的评价体系从现实竞争力和潜在竞争力两个因素抽取为一级指标,以规模、质量、业务结构、效率、成长性五个因素设为二级指标。从实证的角度对银行A、银行B、银行C、银行D、银行E五大国有银行进行分析验证,对其属性值进行和谐性与非和谐性检验得出,银行B竞争能力最强,银行E竞争能力最弱,五大国有银行均有改进空间。  相似文献   

20.
以物理学力学理论为基础,在考虑小麦穗自重,风力大小、风力大小、方向及作用点的因素下,将茎杆状态分为无风情况下的静态过程和有风情况下的动态过程,分别建立小麦蜡熟期茎杆的静态和动态抗倒伏模型.提出合理假设,得到2008年和2011年数据中各品种的机械强度、茎杆鲜重和重心高度的计算公式,再结合已给的倒伏指数公式,计算得到各小麦品种的倒伏指数;接下来,通过斯皮尔曼相关系数分判断倒伏指数与外部特征因素的相关性大小;最后,在考虑穗自重,风力大小、方向及作用点,茎杆变形能的影响因素下,分别建立小麦抗倒伏静态模型和动态模型.其中静态模型以临界力为计算目标,动态模型同时考虑穗自重和风载因素,最终将静态模型和动态模型结合作为小麦抗倒伏模型.文章最后利用已知数据,计算得到抗倒伏模型各个参数,同时对动态模型进行仿真,得到在一定风速下茎杆摆动的运动轨迹.在此基础上,考虑到该模型为典型的非线性动力模型,利用相平面分析法发现存在明显混沌现象,并进一步找出可能导致混沌的相关特性参数.  相似文献   

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