基于模态应变能密度理论的网架结构损伤识别方法

为了研究网架结构的损伤检测方法,根据应变能密度理论,提出采用单元模态应变能密度差值作为网架结构损伤识别指标的方法,以损伤单元模态应变能密度差值的大小初步确定单元的损伤程度。分析了5种具有代表性的损伤工况,并在数值计算结果中引入了白噪声。结果显示,在一阶模态下,针对单损伤、多损伤和轻微损伤、严重损伤等不同损伤工况,损伤杆件的模态应变能密度差值均为高值。因此,该方法可以有效识别出网架结构的损伤位置,根据损伤单元的模态应变能密度差值大小初步确定单元的损伤程度,且在一定的噪声水平下具有较强的鲁棒性,对网架结构损伤识别具有参考价值。     

Estimation in the generalized Poisson model via robust testing

An estimation method is presented which compromises robust efficiency with computational feasibility in the case of the generalized Poisson model. The formal setup is built on flexible nonparametric extensions of the underlying model. The estimation efficiency is expressed via minimax properties of tests resulting from expansions of estimators. The nonparametric neighborhoods related to the proposed score function are exemplified and a real data case is analysed. The resulting method balances several qualitative features of statistical inference: strong differentiability (asymptotic derivations are more accurate), efficiency and natural model extension (quality of formal basic assumptions).     

Robustness to the unavailability of data in block designs

We present general results for finding or boundingt _maxB , the maximum number of arbitrary whole blocks of observations which can be removed from a block design, and still leave all of the elementary treatment contrasts estimable. The block sizes may be larger than the number of treatments. The results are applied to BBDs, reinforced BIBDs and BBDs, BTIBDs, and a series of variance balanced incomplete block designs with two block sizes. Also given for most of these designs, are results fort _max, the maximum number of arbitrary, scattered observations that can become unavailable, and still leave all of the elementary treatment contrasts estimable.The work was undertaken while Dr. Whittinghill was visiting Ohio State University, and supported by a grant from the Natural Sciences Division, Colby College, Waterville, Maine.     

二阶自回归效应有限时间最优相对保费稳健性

在汽车保险奖惩系统相对保费研究中,需要考虑随机效应的动态异质性。在假设随机效应是一个二阶自回归随机序列的条件下,李俊海、赵振英、常沙沙(2011)给出了有限时间下最优相对保费计算公式,但是没有研究该公式的稳健性。在相同条件下,可以证明该文保费公式的稳健性。     

基于复杂多响应相关性的稳健性优化设计

本文对目前复杂多响应问题中,响应间相关性复杂问题的稳健性优化设计方法进行了分析和总结,考察了2种复杂多响应的稳健优化技术,比较了各种方法的特点同时又考虑了稳健性满意度函数法,并对其进行了优化。研究结果表明,最优化稳健性满意度函数法能够很好的平衡复杂多响应中的优化与稳健性的问题,可以很好的解决现代工业产品中只考虑最优化忽略稳定性而导致"召回门"不断的问题。     

供应链鲁棒性影响因素及度量研究

鉴于当今世界上的可以影响供应链功能的条件的剧烈变化,提高供应链的鲁棒性迫在眉睫。本文致力于给出供应链鲁棒性的具体定义和影响因素,将供应链鲁棒性具体化,以概率形式进行表达,给出在发生点失和链断条件下供应链鲁棒性的变化,并且对供应链的鲁棒性进行度量。     

Hypothesis testing and parameter estimation based onM-statistics ink samples with unequal variances

Summary Ink samples with unequal variances,M-tests for homogeneity ofk location parameters are proposed. The asymptoticχ ²-distributions of the test statistics and the robustness of the tests are investigated. NextM-estimators (ME’s) of parameters are discussed. Furthermore positive-part shrinkage versions (PSME’s) of theM-estimators for the location parameters are considered along with modified James-Stein estimation rule. In asymptotic distributional risks based on a special feasible loss, it is shown that the PSME’s dominate the ME’s, and preliminary test and shrinkageM-versions fork≧4.     

ON THE CONSISTENCY OF REGRESSION‐BASED MONTE CARLO METHODS FOR PRICING BERMUDAN OPTIONS IN CASE OF ESTIMATED FINANCIAL MODELS

In many applications of regression‐based Monte Carlo methods for pricing, American options in discrete time parameters of the underlying financial model have to be estimated from observed data. In this paper suitably defined nonparametric regression‐based Monte Carlo methods are applied to paths of financial models where the parameters converge toward true values of the parameters. For various Black–Scholes, GARCH, and Levy models it is shown that in this case the price estimated from the approximate model converges to the true price.     

Direct density estimation as an ill-posed inverse estimation problem

A possible definition of ill-posedness in statistical estimation is the lack of qualitative robustness. In this sense direct density estimation shares ill-posedness with the more obviously ill-posed indirect density estimation models, of which it is a special case. A general construction pattern for estimators is proposed, based on suitable preconditioning, that works for both direct and indirect density estimation. Special emphasis is on its application to the direct case, where in general it yields delta-sequence estimators. More specifically both kernel and series type estimators are included depending on the choice of preconditioning operator. In particular sinc and other flattop kernel estimators emerge in a natural way.     

资本结构影响因素稳健性检验

关于资本结构影响因素的理论和实证研究存在很多相互矛盾的结论,人们通常把这个问题归咎于外部因素的影响,而没有怀疑资本结构理论自身的稳健性;本研究发现相互矛盾的研究结果并非由外部因素引起,而是由于资本结构理论本身缺乏较强的稳健性。因此,传统的资本结构理论并不适用于指导我国企业的融资实践,应该从企业外部,而不是过去理论强调的“从企业内部”去寻找影响资本结构的因素。