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311.
In this paper, we consider the situations in which a middle part of the sample is lost or removed from the experiment. The left-censored sample and Type-II right-censored sample are special cases of this scheme. Point and interval reconstructors for lost failure times are obtained, while the underlying distribution is exponential. To illustrate the performance of the proposed procedures, two numerical examples based on the real data sets are presented. In the case of two-parameter, a simulation study has been done and also the sensitivity of the results to deviations from the true distribution is investigated. 相似文献
312.
Stochastic modeling of the geology in petroleum reservoirs has become an important tool in order to investigate flow properties in the reservoir. The stochastic models used contain parameters which must be estimated based on observations and geological knowledge. The amount of data available is however quite limited due to high drilling costs etc., and the lack of data prevents the use of many of the standard data driven approaches to the parameter estimation problem. Modern simulation based methods using Markov chain Monte Carlo simulation, can however be used to do fully Bayesian analysis with respect to parameters in the reservoir model, with the drawback of relatively high computational costs. In this paper, we propose a simple, relatively fast approximate method for fully Bayesian analysis of the parameters. We illustrate the method on both simulated and real data using a two-dimensional marked point model for reservoir characterization. 相似文献
313.
Mustapha Sali 《生产规划与管理》2013,24(10):769-785
This paper examines the centralised monitoring of an upstream supply chain (USC) in the context of a mass customisation production system. We propose an adaptation of the material requirement planning framework to manage demand uncertainty at each stage of the USC. New analytical relations that exploit structural information on demand beyond the frozen horizon are developed for efficient decision-making and appropriate information sharing among the productive supply chain units. A numerical example to illustrate the implementation of the new analytical relations is provided, and a synthesis of benchmarks performed in the automotive industry is presented. 相似文献
314.
Methods: Based on the index S (S = SENSITIVITY (SEN) × SPECIFICITY (SPE)), the new weighted product index Sw is defined as Sw = (SEN)2w × (SPE)2(1-w), where (0≤w≤1). The Sw is developed to be a new tool to select the optimal cut point in ROC analysis and be compared with the other two commonly used criteria.
Results: Comparing the optimal cut point for the three criteria, the wave range of the optimal cut point for the maximized weighted Youden index criterion is the widest, the weighted closest-to-(0,1) criterion is the narrowest and the weighted product index Sw criterion lays between the ranges of the two criteria. 相似文献
315.
《Omega》2017
In the analytic hierarchy process (AHP), interval judgments instead of precise ratios are widely accepted and can be practically used to solve decision-making problems when uncertainty exists because of scant information available or insufficient understanding of the problem. This paper presents a simple and effective method for finding the extreme points in a range of interval ratios (such as loose articulation, minimum number of interval ratios, and general interval ratios) and ultimately for establishing the dominance relations among alternatives using the identified extreme points. This is followed by an enumeration or simulation approach to manage situations in which the best or a full ranking of alternatives remains unidentified. 相似文献
316.
基于非正态分布的投资风险测度方法 总被引:2,自引:0,他引:2
本文通过计算风险点对投资项目的风险进行定量分析,引进当量正态化的方法解决了独立变量非正态分布下的风险的测度问题,在此基础上提出一种新的投资项目风险测度方法。 相似文献
317.
利用Banach不动点定理讨论一类带有初值条件的n阶迭代泛函微分方程解的存在性和唯一性. 相似文献
318.
Michel H. Montoril Aluísio Pinheiro Brani Vidakovic 《Scandinavian Journal of Statistics》2019,46(1):215-234
We consider a process that is observed as a mixture of two random distributions, where the mixing probability is an unknown function of time. The setup is built upon a wavelet‐based mixture regression. Two linear wavelet estimators are proposed. Furthermore, we consider three regularizing procedures for each of the two wavelet methods. We also discuss regularity conditions under which the consistency of the wavelet methods is attained and derive rates of convergence for the proposed estimators. A Monte Carlo simulation study is conducted to illustrate the performance of the estimators. Various scenarios for the mixing probability function are used in the simulations, in addition to a range of sample sizes and resolution levels. We apply the proposed methods to a data set consisting of array Comparative Genomic Hybridization from glioblastoma cancer studies. 相似文献
319.
利用转换波(P-SV)的传播速度比纵波低,传播不受孔隙流体的影响,传播规律和纵波有较大的区别,可以进行有效的油气识别。针对鄂尔多斯盆地储层以陆相中的三角洲平原分流河道砂体为主,储层分布变化大,横向上低孔低渗,储层物性的非均质性比较强,P-SV波资料处理与P波资料处理有一些差异的特征,对SLG气区实际3D-3C地震资料处理中的转换波静校正问题、共转换点(CCP)道集抽取方法、转换波的速度分析方法、动校正方法及转换波和纵波比例压缩方法等进行了研究,建立了3D-3C地震资料处理方法和技术,并取得了良好的应用效果,可以将该方法在实际生产中推广应用。 相似文献
320.