Some imputation methods to compensate with non-response for estimation of population mean in two-occasion successive sampling

Abstract

Non-response is an unavoidable phenomenon in almost all sample survey, and if it is not dealt carefully at the very starting of the analysis, results may lead to significant biases in the survey estimates. Keeping these facts in mind and inspired by the work of Singh (2009 Singh, S. 2009. A new method of imputation in survey sampling. Statistics 43 (5):499–511. doi:10.1080/02331880802605114.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), this article suggests some alternative efficient methods to deal with the missing data problems at the beginning of the analysis and proposes estimation procedures of the current population mean in two-occasion successive sampling. The properties of the resultant estimation procedures have been examined and supplemented with empirical studies. Results have been critically analyzed, and recommendations are made to the survey practitioners.     

On weighted Renyi’s entropy for double-truncated distribution

In a recent paper, Nourbakhsh and Yari (2017 Nourbakhsh, M., and G. Yari. 2017. Weighted Renyi’s entropy for lifetime distributions. Communications in Statistics—Theory and Methods 46 (14):7085–98.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) introduce the weighted version of Renyi’s entropy for left/right truncated random variables and studied their properties in context of reliability analysis. In the present communication we extend the notion of weighted Renyi’s entropy for two-sided truncated random variable. In reliability theory and survival analysis, this measure may help to study the quantitative-qualitative information spectrum of a system/component when it fails between two time points. Various aspects of weighted Renyi’s interval entropy have been discussed and some mistakes in the preceding literature have also been corrected. These results generalize and enhance the related existing results that are developed based on weighted Renyi’s entropy for one-sided truncated random variable. Finally, a simulation study is added to provide the estimates of the proposed measure and to demonstrate the performance of the estimates.     

Estimation of population mean in successive sampling under super-population model in presence of random non response situations

The present work is an attempt to estimate the population mean on the current occasion in two-occasion successive (rotation) sampling in presence of random non response situations. The estimation strategy has been constructed under a super-population model design approach with the help of imputation technique. The estimators proposed on the current occasion cover the cases of occurrences random non responses on either of the occasions. Detail behaviors of the proposed class of estimators have been studied and its performance has been examined with the sample mean estimator. The results are demonstrated through empirical studies which establish the effectiveness of the proposed class of estimators. Suitable recommendations have been put forward to the survey statisticians for its practical application.     

Reliability analysis for stress-strength model from a general family of truncated distributions under censored data

Abstract

Under progressive Type-II censoring, inference of stress-strength reliability (SSR) is studied for a general family of lower truncated distributions. When the lifetime models of the strength and stress variables have arbitrary and common parameters, maximum likelihood and pivotal quantities based generalized estimators of SSR are established, respectively. Confidence intervals are constructed based on generalized pivotal quantities and bootstrap technique under different parameter cases as well. In addition, to compare the equivalence of the strength and stress parameters, likelihood ratio testing of interested parameters is provided as a complementary. Simulation studies and two real-life data examples are provided to investigate the performance of proposed methods.     

Stable International Environmental Agreements with a Stock Pollutant,Uncertainty and Learning

In this paper I address the question of how uncertainty about damage costs and the possibility of resolving that uncertainty in the future affects the incentives for countries to join an international environmental agreement. I use a two-period model with a stock pollutant where the number of countries generating pollution can be arbitrarily large. The stability concept employed is such that size of the stable IEA can be anywhere between 2 and the grand coalition of all countries depending on parameter values. The dynamic structure allows two different membership rules for an IEA: fixed (countries commit at the outset to be members for both periods) or variable (countries decide each period whether to join). I show that with fixed membership learning results in at least as high membership and global welfare as no learning (unless both the expected value and variance of damage costs are high). With variable membership, learning leads to higher membership (in the second period) but lower global welfare than no learning. For most parameter values variable membership results in higher global welfare than fixed membership.     

关于盈亏平衡分析两个模型的研究

在投资项目评估中，盈亏平衡分析是一种常用的方法，一般来说，它不考虑通货膨胀因素．但是由于通货膨胀的存在，盈亏平衡点会发生变化，这样投资项目评估的可靠性也将受到影响．文章在假定通货膨胀存在的条件下，通过对两种模型（模型Ⅰ和Ⅱ）的分析，发现模型Ⅱ的盈亏平衡产量小于模型Ⅰ的盈亏平衡产量，但二者都大于通常意义下的盈亏平衡产量．文中还阐述了通货膨胀条件下，盈亏平衡点不变的条件．     

Back-to-back mixtures of discrete distributions

A method for expanding the choices for fits of discrete data is given. The method is very simple: a breakpoint is chosen for the data set on either side of which two separate discrete distributions are fit. Thus, the method is a mixture of two discrete distributions. The method is appealing in light of the ease with which the likelihood equations simplify. For illustrative purposes, the method is used on the data set that motivated its conception.     

以塑性应变和损伤为参变量的广义非局部损伤本构方程

将塑性应变和非局部损伤取为内变量，引入耗散势，利用连续介质损伤力学和热力学第二定律，建立了一个能全面描述材料本构行为的非局部非弹性损伤本构方程，用该模型计算了单位、单压状态下混凝土材料及20#钢的应力-应变关系曲线，取得了较好的结果．     

加强计算机仿真在数学物理方法教学中的应用

计算机仿真可广泛应用于复变函数的积分计算、级数展开、留数计算、积分变换以及特殊函数的计算及图形显示中,而且对于三类典型的数学物理方程的求解也显得简单明了,尤其对于波动方程、热传导方程能动态地演示方程的解随时间的变化规律。计算机仿真方法对培养同学们的数学建模能力、编程实践能力、创新思维能力具有重要作用和指导意义。在本科的教学实践中应切实加强计算机仿真的地位和作用。     

步进电机最佳变频控制研究

通过讨论功率步进电机的运行频率与输出转矩之间的动力学关系,提出了电机输出最大转矩的变频控制新方法。该方法对机床等机械设备进行技术改造,实现经济型数控系统具有实用价值。