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1.
根据生理药动学模型的特点,把非线性药动学模型转化为线性模型,并验证线性模型的精确性.在此基础上,构造估计药动学模型参数的目标函数,并利用非线性优化算法求解模型参数.仿真结果表明,我们的算法具有快速、精确和稳定的特点.给出了一种快速估计复杂生理药动学模型参数的方法,这为解决复杂生理药动学模型的参数估计问题提供了一种有效工具.  相似文献   

2.
随着我国经济的快速发展,个人信贷业务扩大,给银行带来收益的同时必然存在风险,针对传统个人信用评估方法的不足,鉴于支持向量机具有全局收敛性和良好的推广能力,本文将这种方法应用到信用评估中,利用支持向量机的方法对个人信用进行实证评估,并与K最近邻模型方法进行比较,得出了该方法的可行性和优越性,为银行建立一套完善的评估体系提供依据。  相似文献   

3.
黄国兴  曹蓉 《运筹与管理》2009,18(6):155-158
为了解决传统生产计划制订不适应现代市场需求的问题,本文将CBR引入到生产计划制订当中,成功建立了生产计划的推理模型,并讨论了模型的推理机制,该方法对生产计划的快速制订具有一定的参考意义。  相似文献   

4.
本征正交分解及Galerkin投影是解决复杂非线性系统模型降阶问题常用的方法.然而,该方法在构造降阶系统过程中只截取基函数的部分模态,这通常会使得降阶系统不准确.针对该问题,提出了对降阶系统误差进行快速校正的方法.首先应用Mori-Zwanzig格式对降阶系统的误差进行分析,理论上得到误差模型的形式和有效预测变量.再通过偏最小二乘方法构造预测变量和系统误差的多元回归模型,建立误差预测模型.将所构造的误差预测模型直接嵌入到原降阶系统,得到新的降阶系统在形式上等价于对原模型的右端采用Petrov-Galerkin投影.最后给出了新的降阶系统的误差估计.数值结果进一步说明了所提方法能有效地提高降阶系统的稳定性和准确性,且具有较高计算效率.  相似文献   

5.
提出了一种叫做逐元估计法的方法用来估计变系数模型中的未知函数和它们的导数,构造了一种快速选择估计量窗宽和快速计算大量估计点的方法,推导了估计量的渐近正态性.通过Monte Carlo模拟研究了估计量的有限样本性质.  相似文献   

6.
本文讨论了线性规划问题:≥0,t=1,2,…,n)解的性质。此规划问题可来源于网络流模型,也可来源于库存模型等。通过对该问题解的基本特征进行描述,得到了最多n步即可得到精确解的快速求解方法。  相似文献   

7.
基于遗传算法的企业风险管理组合模型的分析   总被引:1,自引:0,他引:1  
石玉英  糜麟  乔林  刘亮 《运筹与管理》2005,14(2):149-153
本提出了企业关键风险体的概念,建立了基于关联成本和关联收益的风险管理组合净收益模型。并通过一个典型算例详细说明企业风险管理组合选择的标准和过程。实验结果表明该方法具有简单快速准确等特点,对企业的风险管理和决策具有一定的帮助和指导意义。  相似文献   

8.
人工神经网络近年来得到了快速发展,将此方法应用于数值求解偏微分方程是学者们关注的热点问题.相比于传统方法其具有应用范围广泛(即同一种模型可用于求解多种类型方程)、网格剖分条件要求低等优势,并且能够利用训练好的模型直接计算区域中任意点的数值.该文基于卷积神经网络模型,对传统有限体积法格式中的权重系数进行优化,以得到在粗粒度网格下具有较高精度的新数值格式,从而更适用于复杂问题的求解.该网络模型可以准确、有效地求解Burgers方程和level set方程,数值结果稳定,且具有较高数值精度.  相似文献   

9.
复杂网络广泛存在于日常生活,首先,给出几类标准的网络模型;然后,利用稳定性控制方法设计并实现了具有时滞与非时滞耦合的复杂网络模型快速控制;最后,通过构造优化Lyapunov函数,讨论其模型的射影同步问题,得到了系统全局稳定的条件和有效的控制器,以实例数值验证其方法的可行性。  相似文献   

10.
本文考虑具有区域变换跳跃幅度服从对数均匀分布的跳扩散模型的期权定价问题.本文给出了这样模型的期权定价方法和计算过程,当中采用了FFT(快速傅里叶变换法),最后给出了数值计算结果.  相似文献   

11.
Many space mission planning problems may be formulated as hybrid optimal control problems, i.e. problems that include both continuous-valued variables and categorical (binary) variables. There may be thousands to millions of possible solutions; a current practice is to pre-prune the categorical state space to limit the number of possible missions to a number that may be evaluated via total enumeration. Of course this risks pruning away the optimal solution. The method developed here avoids the need for pre-pruning by incorporating a new solution approach using nested genetic algorithms; an outer-loop genetic algorithm that optimizes the categorical variable sequence and an inner-loop genetic algorithm that can use either a shape-based approximation or a Lambert problem solver to quickly locate near-optimal solutions and return the cost to the outer-loop genetic algorithm. This solution technique is tested on three asteroid tour missions of increasing complexity and is shown to yield near-optimal, and possibly optimal, missions in many fewer evaluations than total enumeration would require.  相似文献   

12.
Doklady Mathematics - A method for efficient comparison of a symbol sequence with all strings of a set is presented, which performs considerably faster than the naive enumeration of comparisons...  相似文献   

13.
The enumeration of sequences plays an important part in combinatorial enumeration since sequences may be used as a means for encoding combinatorial structures. In the main, the enumeration of sequences has been treated by a collection of methods individually applied in particular cases. We present here a uniform constructive method for dealing with a large class of sequence problems. We obtain the generating function as the trace of an expression involving certain incidence matrices, expressions which are obtainable immediately from the combinatorial structure of a problem. The method relies on certain properties of matrices whose rank is equal to one. We demonstrate that these properties may be used to derive the required generating functions explicitly or, in more complex cases, as solutions to systems of linear equations. Results for permutations may be derived from those for sequences, and in certain frequently encountered special cases this operation may be carried out by a straightforward substitution. Applications of the method presented here will be given in Part II.  相似文献   

14.
Combinatorial enumeration by means of unit subduced cycle indices (USCIs) is discussed by using the group I (A5) and the related groups as examples. A modified method for the derivation of USCIs is presented, where a subduced mark table is a key concept. Several properties of USCIs are discussed by clarifying the relationship between double cosets and the subduction of coset representations, which gives an alternative formulation of the USCIs. This treatment provides us with a new prospect concerning the properties of double cosets. The usefulness of subduced cycle indices and cycle indices derived from USCIs is exemplified by enumeration based on an icosahedron.  相似文献   

15.
林浩  林澜 《经济数学》2013,30(1):17-21
通过组合最优化的理论和方法,研究机器有负荷(时间)限制的指派问题,证明其NP困难性,并建立多项式可解的特殊情形算法及一般情形的隐枚举算法.  相似文献   

16.
A method is presented to solve that class of network flow problems, which may be formulated as one source - multiple destination minimum cost flow problems with concave costs. The global optimum is searched using a branch and bound procedure, in which the enumeration scheme is based on a characterization of the optimal solution set, while linear relaxations of the original problem provide lower bounds.  相似文献   

17.
Summary  A deterministic switching regressions estimator is evaluated using an evolutionary method based on genetic algorithms. Distinctive aspects of the method include (1) a combination of simple and random chromosomal crossover and (2) extension of the principle of natural selection to internal parameterization. The evolutionary computation duplicates, significantly faster, the results of an existing enumerative method in samples small enough to permit enumeration. It also provides the ability to calculate the estimator in much larger sample sizes than is possible with the enumerative approach. An example problem from the United States gasoline market is given. Funding support provided by the Gerondelis Foundation, Inc. is gratefully acknowledged.  相似文献   

18.
A polyomino is a connected collection of squares on an unbounded chessboard. There is no known formula yielding the number of distinct polyominoes of a given number of squares A polyomino enumeration method, faster than any previous, is presented. This method includes the calculation of the number of symmetric polyominoes. All polyominoes containing up to 24 squares have been enumerated (using ten months of computer time). Previously, only polyominoes up to size 18 were enumerated.  相似文献   

19.
Uncovering hidden change-points in an observed signal sequence is challenging both mathematically and computationally. We tackle this by developing an innovative methodology based on Markov chain Monte Carlo and statistical information theory. It consists of an empirical Bayesian information criterion (emBIC) to assess the fitness and virtue of candidate configurations of change-points, and a stochastic search algorithm induced from Gibbs sampling to find the optimal change-points configuration. Our emBIC is derived by treating the unknown change-point locations as latent data rather than parameters as is in traditional BIC, resulting in significant improvement over the latter which is known to mostly over-detect change-points. The use of the Gibbs sampler induced search enables one to quickly find the optimal change-points configuration with high probability and without going through computationally infeasible enumeration. We also integrate the Gibbs sampler induced search with a current BIC-based change-points sequential testing method, significantly improving the method’s performance and computing feasibility. We further develop two comprehensive 3-step computing procedures to implement the proposed methodology for practical use. Finally, simulation studies and real examples analyzing business and genetic data are presented to illustrate and assess the procedures.  相似文献   

20.

An efficient algorithm is given for the resolution of relative Thue equations. The essential improvement is the application of an appropriate version of Wildanger's enumeration procedure based on the ellipsoid method of Fincke and Pohst.

Recently relative Thue equations have gained an important application, e.g., in computing power integral bases in algebraic number fields. The presented methods can surely be used to speed up those algorithms.

The method is illustrated by numerical examples.

  相似文献   


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