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1.
一维单个守恒型方程的二阶熵耗散格式   总被引:2,自引:1,他引:1  
本文考虑一维单个守恒律方程,对其设计了一种非线性守恒型差分格式,此格式为二阶Godunov型的,用的是分片线性重构,重构函数的斜率是根据熵耗散得到的,格式满足熵条件,且数值实验表明格式具有非线性稳定性,在此格式中一个所谓的熵耗散函数起了很重要的作用,它在每个网格的计算中耗散熵,在文中我们给出了熵耗散函数应满足的条件,并给出了一种具体的构造形式,最后给出了一些数值算例,从中可看出熵耗散函数是如何抑制非物理振荡的,及格式对计算的有效性。  相似文献   

2.
用Hopfield网络计算约束条件下系统熵的最小值   总被引:1,自引:0,他引:1       下载免费PDF全文
有约束条件时系统熵的最小值问题是NP 完全问题,该文利用Hopfield人工神经网络解决组合优化问题的能力计算了此问题,得到了较好的结果.  相似文献   

3.
不完备决策系统关联于数据分析,其属性约简具有应用意义,并已具有基于容差关系的条件熵研究.基于相似关系,研究不完备决策系统的条件熵属性约简及其算法.利用相似关系确立条件熵,提出等价于广义决策函数保持约简的条件熵保持约简,建立具有误差容忍机制的条件熵容忍约简;针对两种新建属性约简,揭示它们间的扩张关系与强弱关系,构建相应的全局算法与局部算法;最后,提供决策表实例分析,说明基于相似关系的条件熵属性约简及其算法的有效性.相关研究完善了不完备决策系统属性约简,具有理论价值与应用意义.  相似文献   

4.
本文用Shannon熵函数的观点及最大离散熵原理,探讨了对随机试验项目的优选问题:即压缩某种“不确定性”试验项目的实施与探索.并通过应用实例的计算,获得了满意的聚类效果.这种方法对于信息资料的数据处理及压缩“不确定性“验项目具有普遍意义.  相似文献   

5.
本文用WENO算法解决双曲型守恒律方程组初(边值)问题.给出一种满足熵条件、Sδ熵条件和边界熵条件的WENO算法.通过这个算法就能得到守恒律方程组的数值解,数值解和理论解是非常吻合的.  相似文献   

6.
基于极大熵准则的先验分布确定方法   总被引:2,自引:0,他引:2  
借助于熵的概念,讨论了用极大熵的思想来确定先验分布的几种情形,给出了在各种情形下先验分布的形式和结论,从而提供了确定先验分布的一种有效的方法。  相似文献   

7.
针对延迟界面和缓冲界面的设置位置不同会对供应链的运营绩效产生比较大的影响,应用熵理论的评价方法对供应链界面决策进行了研究分析。熵理论的评价方法不需要对判断矩阵进行一致性检验,计算步骤较为简便,计算量较少,且避免了人为主观因素对决策结果的影响,具有一定的现实意义。  相似文献   

8.
本文研究了非线性抛物问题熵解的正性依赖于初始资料和方程右端项的正性以及熵解的稳定性依赖于方程右端项的弱 L~1摄动.  相似文献   

9.
一种基于图论与熵的专家判断客观可信度的确定方法   总被引:2,自引:0,他引:2  
本文给出一种群决策中确定专家判断可信度的方法,其主要思路是首先通过图论中最小生成树的方法提取专家判断矩阵的全部信息,其次,使用相对熵指标确定获得专家判断的最终结果,并同时衡量专家自身判断的统一程度,从而确定专家判断的相对客观可信度。最后,文章给出一个典型的算例以说明该方法的可行性和有效性。  相似文献   

10.
吴金平 《中国科学A辑》1990,33(11):1162-1168
本文考察了非平衡态热力学稳定性的超熵产生判据和动力学线性稳定性原理之间的关系.结果表明:超熵产生判据所要求的条件,在一般情况下是判定系统稳定性的充分条件,但不是必要条件,它比线性稳定性原理所要求的条件强得多.只有在二阶超熵二次式中的矩阵与动力学线性化方程组中的矩阵的乘积为对称阵的情况下,超熵产生判据所要求的定态稳定的条件(δxP正定)是充要的.关于Fox用来证明超熵,δ2S不是一个Liapounov函数的“反例”实际上和超熵产生判据并不矛盾.分析结果还表明:超嫡产生判据的适用性不受动力学线性化方程组的矩阵的对称性限制.围绕非平衡定态的超熵,δ2S是热力学系统的一个Liapounov函数.  相似文献   

11.
本文用新方法描述了气藏开采中的井筒边界条件,从而建立了均质气藏内真实气体渗流问题的新模型;并在无限大、有界封闭、有界定压三种典型外边界条件下,得出了均质气藏中拟压力函数的精确解析表达式;最后给出了本文的拟压力表达式在气井试井分析中的应用.  相似文献   

12.
It has been customary to implement Good Manufacturing Practices (GMP) in pharmaceutical organizations as a systematic and comprehensive quality approach and sometimes by regulatory enforcement. In this scenario, determination of the obvious entropy/disorder arising during the implementation has not been taken care of yet. Therefore, this paper gives the basis for applying query and visual perception of GMP system driven visualization approach, particularly the Laplace equation, to the determination of disorder and deviation pattern inside the GMP system applied in the organization. In this study, a three-dimensional mesh approached with raw and intermediate input handled under GMP parameter is considered to produce high quality products with minimum entropy (variation distribution) by adding the analogy wise different GMP parameters and process variables with Gauss Seidel iteration and thus producing visual picture of the entire system. The approximation involved in applying the equations to the GMP compliant aseptic region was analyzed. Using numerical technique and computer program, the Gauss Seidel iteration equations have been solved with appropriate GMP parameter and process variable. The result indicates that deviations vary over the GMP compliant system and that the process entropy affects the totality of disorderness. Experiments with model of GMP compliant reproductive medicine laboratory confirm that the new method provides optimal manufacturing maintaining GMP and high product quality through the visual representation of the entire system and activity to bring into notice the deviations.  相似文献   

13.
The scope of this work is to reveal, by means of numerical methods, the escape process in a Hamiltonian system with five exits which describes the problem of rearrangement multichannel scattering. For determining the influence of the energy on the nature of the orbits we classify starting conditions of orbits in planes of two dimensions. All the complex basins of escape, associated with the five escape channels of the system, are illustrated by using color-coded diagrams. The distribution of time of the escape is correlated with the corresponding escape basins. The uncertainty (fractal) dimension along with the (boundary) basin entropy are computed for quantifying the degree of fractality of the dynamical system.  相似文献   

14.
In this article, the author uses the compensated compactness method coupled with some basic ideas of the kinetic formulation developed by Lions, Perthame, Souganidis and Tadmor to give a refined proof for the existence of global entropy solutions to a system of quadratic flux. The fire-new method of reduction of Young measures is a pith of this work.  相似文献   

15.
在其深层次机理上,港口物流系统竞争能力必受其物质技术支撑体系的制约.结合智慧港口和第五代港口基本理论,可得出深层次物质技术支撑体系主要有:物质资源禀赋、城市经济系统、物联网系统、港口经营系统、绿色效率系统等.以相关港口物流系统竞争力基本理论为指导,考虑到中国各港口的实际情况,结合数据获得的难易程度,分别从基础设施、发展环境、智慧技术、服务水平、低碳绩效五个方面遴选出18个评价指标,按照模糊信息熵理论,利用全国24个主要港口2001—2013年的原始数据,通过数学软件Matlab编程,计算出系统层指标的信息熵和权重及全国8个代表性港口2013年的竞争能力综合评价值,并以福建省福州港为例,对其进行横向比较和纵向时序分析.  相似文献   

16.
In this paper the author addresses the modelling of the laser cutting process. Despite the attention paid to this process by the scientific community, the underlying physical phenomena are still only marginally understood. The models used in the literature are often highly simplified and focus on single effects such as exothermic reactions of the melt with the assist gas whilst neglecting other important physical mechanisms. In this work a three-dimensional fully coupled model for the laser cutting process is used. It will be shown by the author that simplifications like reduction in model dimension are not admissible for the investigation of the complete process. However, it has also been found by the author that currently available computer hardware is not capable of producing results at the necessary rate and cost required for parametric studies. Results from two simulation runs, which were performed in course of a larger study amounting to 17 300 cpu hours on a SGI origin 3400 system, are presented. Nevertheless, these results form a cautionary example with regard to the numerical models applied and assumptions frequently introduced by other authors.  相似文献   

17.
利用brick-wall方法,计算了Schwarzschild-anti-de Sitter时空中Dirac场的统计熵,讨论了Dirac粒子的自旋对统计熵的影响.结果表明,忽略远离围绕系统的真空的贡献,Dirac场的统计熵包含与黑洞视界面积成正比的平方反比发散项和对数发散项,整个表达式的结构与黑洞熵的结构不一样.对应于|∧|r2h 的不同取值,对数发散项的贡献可以为正、负或零.  相似文献   

18.
王翯华  朱建军  杨萍 《运筹与管理》2018,27(10):146-153
研究不确定情景下大型客机协同研制正态云模型风险评估方法及应用问题。建立了正态云模型的偏差熵测度,提出了面向云模型偏差熵的指标权重确定模型,构建了面向多数据类型的正态云模型风险评估方法。建立了涵盖工艺标准、工艺方案等五个指标的大型客机协同研制供应商工艺技术风险评估指标体系,并基于正态云模型评估方法进行了实际应用。  相似文献   

19.
2008年中国足球超级联赛成绩与技术统计的因子分析   总被引:1,自引:0,他引:1  
通过查阅资料,收集、并整理了2008年中超联赛15支队伍210场比赛的技术统计.运用因子分析法对比赛成绩与技术统计的关系进行了研究,命名并分析影响比赛成绩的5个因子.旨在揭示统计指标与比赛成绩的特点与规律,为我国足球运动的理论与训练提供科学依据。  相似文献   

20.
In this paper we define a very simple invariant η(V^-) for a k-tuple V^-of unitaries in a finite factor von Neumann algebra, and we show how this invariant can replace free entropy in many of the important applications. We also introduce a notion of metric free entropy and some related concepts.We include proofs, using η, of the theorems of Liming Ge and of D. Voiculescu, respectively, on the primeness of and on the absence of Cartan snbalgebras in the noncommutative free group factors.  相似文献   

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