一个Smarandache问题的均值估计

阐述了一个Smmandache问题的均值估计，并利用Perron公式和留数定理，给出了这个问题的一个渐近公式，其余项可以做到D（x^V2）．     

More maximum likelihood oddities

It is shown that the maximum likelihood estimator is superior to the method of moments in estimating the parameter of triangular distributions. It is also shown that the former is not as difficult to calculate as it was previously perceived—thanks to some of its peculiar properties.     

Nonlinear functional models for functional responses in reproducing kernel hilbert spaces

The author proposes an extension of reproducing kernel Hilbert space theory which provides a new framework for analyzing functional responses with regression models. The approach only presumes a general nonlinear regression structure, as opposed to existing linear regression models. The author proposes generalized cross‐validation for automatic smoothing parameter estimation. He illustrates the use of the new estimator both on real and simulated data.     

国内外工程计价方法在房屋估价中的应用

国内外工程计价的一些方法具有计算简便、对技术资料和估价人员技术功底要求不高等特点,可以在房屋估价中参考使用.利用概算指标、类似工程施工图预算指标及平方(立方)英尺经济指标,通过时间、地区和结构差异修正,计算出待估房屋在估价时点的建筑安装工程费用或重置成本.这种估价思路符合房地产估价的"替代性"原理,并具有估算简单、技术性强等特点,能够保证估价结果的准确性.     

油气储量价值评估理论及其实证研究

在借鉴国外矿业权流转市场惯例的同时,结合我国市场经济环境,建立了油气储量价值评估的数学模型,并以某油田S井块为例进行了实证研究,进而对有关参数进行了分析。     

On the robustness of empirical likelihood ratio confidence intervals for location

The authors examine the robustness of empirical likelihood ratio (ELR) confidence intervals for the mean and M‐estimate of location. They show that the ELR interval for the mean has an asymptotic breakdown point of zero. They also give a formula for computing the breakdown point of the ELR interval for M‐estimate. Through a numerical study, they further examine the relative advantages of the ELR interval to the commonly used confidence intervals based on the asymptotic distribution of the M‐estimate.     

Properties of Model-Averaged BMDLs: A Study of Model Averaging in Dichotomous Response Risk Estimation

Model averaging (MA) has been proposed as a method of accounting for model uncertainty in benchmark dose (BMD) estimation. The technique has been used to average BMD dose estimates derived from dichotomous dose-response experiments, microbial dose-response experiments, as well as observational epidemiological studies. While MA is a promising tool for the risk assessor, a previous study suggested that the simple strategy of averaging individual models' BMD lower limits did not yield interval estimators that met nominal coverage levels in certain situations, and this performance was very sensitive to the underlying model space chosen. We present a different, more computationally intensive, approach in which the BMD is estimated using the average dose-response model and the corresponding benchmark dose lower bound (BMDL) is computed by bootstrapping. This method is illustrated with TiO(2) dose-response rat lung cancer data, and then systematically studied through an extensive Monte Carlo simulation. The results of this study suggest that the MA-BMD, estimated using this technique, performs better, in terms of bias and coverage, than the previous MA methodology. Further, the MA-BMDL achieves nominal coverage in most cases, and is superior to picking the "best fitting model" when estimating the benchmark dose. Although these results show utility of MA for benchmark dose risk estimation, they continue to highlight the importance of choosing an adequate model space as well as proper model fit diagnostics.     

Nonparametric Estimation of the Geometric Vitality Function

Recently, Nair and Rajesh (2000 Nair , K. R. M. , Rajesh , G. ( 2000 ). Geometric vitality function and its application to reliability . IAPQR Tran. 25 ( 1 ): 1 – 8 . [Google Scholar]) proposed a measure to describe the failure pattern of components/devices in terms of the geometric mean of the residual life. This measure find applications in modeling life time data. In the present work we provide a nonparametric kernel-type estimator for the geometric vitality function, both in the case of complete and censored samples. The properties of the estimator, under certain regularity conditions, are studied. The performance of the estimator is compared with the empirical estimator using a real data set and simulation studies are carried out using the Monte Carlo method.     

Modeling sensitivity and specificity with a time-varying reference standard within a longitudinal setting

Diagnostic tests are used in a wide range of behavioral, medical, psychosocial, and healthcare-related research. Test sensitivity and specificity are the most popular measures of accuracy for diagnostic tests. Available methods for analyzing longitudinal study designs assume fixed gold or reference standards and as such do not apply to studies with dynamically changing reference standards, which are especially popular in psychosocial research. In this article, we develop a novel approach to address missing data and other related issues for modeling sensitivity and specificity within such a time-varying reference standard setting. The approach is illustrated with real as well as simulated data.     

基于面板数据的无锡物流需求影响因素研究

物流需求影响因素的研究是物流需求预测的基础,文章选取无锡1996年至2011年的面板数据,运用最小二乘估计法得出所选取的11个指标对物流需求的影响系数,对所得系数进行评价,结合无锡物流现状及其影响因素得出结论并提出建议.