基于百分制评标办法运用概率分析的报价方法探讨

在激烈的建筑市场竞争体制下，水电施工企业要想中标必须编制合理报价，不同的评标办法，其编制报价的方法与策略是不相同的，通过对历史投标统计资料的分析，文章提出了一种基于百分制评标办法运用概率分析的报价方法，该方法将量化分析运用于投标决策，为投标报价提供一个科学的，定量的决策依据，运用此方法能确保投标报价不失误，且能得到一个较高的报价评分。     

整数规划模型在计算生物学中的应用

解决计算生物学问题的常规途径是通过建模分析来确定与所研究的生物学过程相对应的一个或多个数学对象(如图、集、矩阵等)，从而将初始的生物学问题转换为数学问题。当这类数学问题较为简单时，可以采用组合数学方法(如鸽巢原理)推导，或者采用概率分析方法求解。然而，很多时候只能获得一个具有数量权重(解为“真”的概率)的试探解。权重值越大，则解越可靠。因而，发现初始生物学问题最佳解答的途径之一就是优化方法，即找到权重函数f(x)达到最大值时的解x^*。     

边坡稳定性概率分析

提出了边坡稳定率分析的具体方法及分析步骤。分析了影响边坡稳定的主要岩体力学指标Ｃ、Φ值的分布函数及安全系数的数学模型。     

快中子零功率反应堆(DF-VI)的临界事故概率分析

本文应用故障树分析方法,对快中子零功率堆(DF-Ⅵ)在启动过程中发生临界事故的可能性做了初步的定量估计。结果表明,该堆每次启动发生临界事故的概率约为10~(-6)量级,得出确保装置启动安全的首要因素是选配合格的操作人员的结论,并对设备的改进提出了一些建议.     

四湖流域旱涝交替事件概率分析

以四湖流域荆门、荆州、石首、监利、潜江5个代表性气象站点1956-2007年的日降水资料为基础,分别选取Z指数法及广义帕累托分布对各气象站春、夏、秋三季的标准降水序列及降水距平序列进行拟合,分析各气象站点在不同季节内发生旱涝灾害的频率,在此基础上采用二维Clayton Copula分布函数拟合春-夏、夏-秋的降水分布,进一步计算出各站点旱涝交替事件的发生概率.结果表明:1)Z指数法比降水距平法更适于分析四湖流域的旱涝情况;2)四湖流域在春-夏、夏-秋两时段发生旱涝交替的频率平均为16.27%,其中,潜江最容易发生旱涝异常现象.春-夏与夏-秋发生旱涝交替事件频率没有明显差别.     

Probabilistic analysis of random contact force between geomembrane and granular material

A probabilistic method based on principle of maximum entropy was employed to analyze the randomness of contact force between geomembrane and granular material. The contact force distribution is exponential according to the proposed method and the grain size is the most important factor that affects the distribution of contact force. The proposed method is then verified by a series of laboratory experiments using glass beads and cobbles as granular material and a very thin pressure, indicating that film is firstly used in these experiments which give a reliable method to measure the contact force at each contact point.     

半圆拱砖砌烟道结构的可靠度分析比较

对某半圆拱砖砌烟道结构计算分析,先根据规范分析抗力及荷载的均值、变异系数,在求定值解的基础上用ANSYS有限元软件进行概率分析,得到了拱顶下缘、拱肩外缘抗拉功能函数概率密度图,以及拱顶下缘、拱肩外缘沿通缝的失效概率。     

岩体结构的可靠性设计

考虑岩体性质的空间变异性和随机性,本文讨论了基于可靠度理论的岩体结构的可靠性设计。分析了岩体结构的可靠性设计的研究现状,提出了面临的问题和相应的措施。     

WSN中基于网格的覆盖控制与群优化研究

覆盖问题是无线传感器网络部署研究的核心内容.指出了无线传感器网络覆盖控制问题的研究重心,并重点探讨了基于网格模型的无线传感器网络覆盖控制与群首优化问题.通过对覆盖概率分析,给出特定环境下监测区域的覆盖概率、群首个数和覆盖损失率之间的定量关系;分析不同参数对网络覆盖问题的影响,用以指导传感器网络的节点部署.最后,利用模拟仿真试验来评定结论.     

Probabilistic analysis of geomembrane puncture from granular material under liquid pressure

A simplified probabilistic analysis of geomembrane punctures from granular material was presented when subjected to liquid pressure. The probability distribution of contact force between geomembrane and granular material was obtained based on the principle of equal probability and assumptions that grains are spheres with constant size. A particle flow code PFC^3D was employed to simulate the contact process which indicates a good agreement with the theoretical probabilistic analysis. The odds of geomembrane puncture from grains of constant size were obtained by evaluating the puncture force which should not exceed the puncture resistance of geomembrane. The effects of grain radius, grain rigidity and liquid pressure were studied in more detail and displayed in graphs. Both high-level of liquid pressure and large grain can result in high risk of geomembrane puncture. The influence of grain rigidity on the geomembrane puncture odds is significant. For granular material with a grain size distribution, the geomembrane puncture odds can be estimated by the grain size distribution, served as weight function and it is a cautious design if the largest grain is chosen as the design grain size.