Computation of an efficient and robust estimator in a semiparametric mixture model

In this article, we propose an efficient and robust estimation for the semiparametric mixture model that is a mixture of unknown location-shifted symmetric distributions. Our estimation is derived by minimizing the profile Hellinger distance (MPHD) between the model and a nonparametric density estimate. We propose a simple and efficient algorithm to find the proposed MPHD estimation. Monte Carlo simulation study is conducted to examine the finite sample performance of the proposed procedure and to compare it with other existing methods. Based on our empirical studies, the newly proposed procedure works very competitively compared to the existing methods for normal component cases and much better for non-normal component cases. More importantly, the proposed procedure is robust when the data are contaminated with outlying observations. A real data application is also provided to illustrate the proposed estimation procedure.     

From industrial restructuring to the financial crisis: Mainstream nationalism and minimum income in the Basque Country

The uneven development of minimum incomes in Spain is one of the factors that explain the significant differences in the poverty indicators that characterize the Spanish regions, generally in favour of the territories most committed to these policies (Basque Country, Navarra and Asturias). However, there are other aspects that deserve some consideration when interpreting the specific method of developing minimum incomes in southern Europe. One aspect has to do with the differing dynamics of countries, such as Spain and Italy, which have opted for a decentralized regional model. In this regard, the regional autonomous initiative of the Basque Country played a decisive role in promoting minimum income programs in the late 1980s. Without its leadership in the launch of the regional minimum income policy, Spanish trade unions would probably not have opted for this method as a mechanism for combating poverty in the 1990s. No Italian region went on to play this driving role at that time. This article analyses the ideological foundations of the Basque minimum income policy introduced in the late 1980s and which grew significantly before and during the crisis that started in 2007-2008. It examines the dominant political narrative on this issue by analysing the discourse of some of the key nationalist leaders involved in the birth and development of the minimum income scheme. The approach shows that the experience of social decline linked to industrial restructuring processes was instrumental in the construction of the nationalist narrative.     

Care in a Time of Austerity: the Electronic Monitoring of Homecare Workers’ Time

Austerity places intense pressures on labour costs in paid care. In the UK, electronic monitoring technology has been introduced to record (and materially reduce) the working time and wages of homecare workers. Based on empirical findings, we show that, in a ‘time of austerity’, care is reductively constructed as a consumption of time. Service users are constructed as needy, greedy, time‐consumers and homecare workers as resource‐wasting time‐takers. We point to austerity as a temporal ideology aimed at persuading populations that individual deprivation in the present moment, self‐sacrifice and the suppression of personal need in the here and now is a necessary requirement to underpin a more secure national future. Accordingly, women in low‐waged care work are required to eschew a rights‐bearing, present‐tense identity and are assumed willing to suppress their entitlements to lawful wages as a sacrifice to the future. By transforming our understandings of ‘care’ into those of ‘time consumption’, and by emphasizing the virtue of present‐tense deprivation, a politics of austerity appears to justify time‐monitoring in care provision and the rationing of homecare workers’ pay.     

Generalized minimum aberration mixed-level orthogonal arrays: A general approach based on sequential integer quadratically constrained quadratic programming

Orthogonal fractional factorial designs and in particular orthogonal arrays (OAs) are frequently used in many fields of application, including medicine, engineering, and agriculture. In this article, we present a methodology and an algorithm to find an OA, of given size and strength, which satisfies the generalized minimum aberration criterion. The methodology is based on the joint use of polynomial counting functions, complex coding of levels, and algorithms for quadratic optimization and puts no restriction on the number of levels of each factor.     

Estimation of the parameter of a dynamically selected population for two subclasses of the exponential family

We introduce the problem of estimation of the parameters of a dynamically selected population in an infinite sequence of random variables and provide its application in the statistical inference based on record values from a non stationary scheme. We develop unbiased estimation of the parameters of the dynamically selected population and evaluate the risk of the estimators. We provide comparisons with natural estimators and obtain asymptotic results. Finally, we illustrate the applicability of the results using real data.     

Estimation of P{X < Y} for geometric—exponential model based on complete and censored samples

This article deals with the estimation of R = P{X < Y}, where X and Y are independent random variables from geometric and exponential distribution, respectively. For complete samples, the MLE of R, its asymptotic distribution, and confidence interval based on it are obtained. The procedure for deriving bootstrap-p confidence interval is presented. The UMVUE of R and UMVUE of its variance are derived. The Bayes estimator of R is investigated and its Lindley's approximation is obtained. A simulation study is performed in order to compare these estimators. Finally, all point estimators for right censored sample from the exponential distribution, are obtained.     

Classical estimation of hazard rate and mean residual life functions of Pareto distribution

Abstract

In this paper we find the maximum likelihood estimates (MLEs) of hazard rate and mean residual life functions (MRLF) of Pareto distribution, their asymptotic non degenerate distribution, exact distribution and moments. We also discuss the uniformly minimum variance unbiased estimate (UMVUE) of hazard rate function and MRLF. Finally, two numerical examples with simulated data and real data set, are presented to illustrate the proposed estimates.     

特低渗透油藏 CO2 驱室内实验研究

针对大庆外围油田特低渗透油藏剩余油潜力大、井网加密效益差、水驱采收率低等问题，提出了特低渗透油藏 CO2驱技术。通过细管实验和天然岩芯 CO2 驱油实验，确定了 CO2 与高台子油田原油的最小混相压力，评价了特低渗透砂岩油藏 CO2 驱油效果。实验结果表明，CO2 驱可以应用于高台子油田，并取得较好的驱油效果。当天然岩芯空气渗透率为0.58 mD 时，在水驱基础上，气驱可以进一步提高采收率 8% 以上，特低渗透油藏实施 CO2 驱油技术是可行的。     

Sequential estimation problems for negative exponential populations

The literature on sequential estimation problems for negative exponential populations has been reviewed here, We attempt to bring in all the published and unpublished materials known to us in a fairly coherent fashion. Both the concepts and theoretical findings are discussed.     

Some tests for the power series distibutions in one parameter using the kullback-leibler information measure

The purpose of the article is, in case of one sample, to obtain tests concerning the parameter in the power series distribution in one parameter using Ku11back-Leibier information measure. The class of power series distibutions contains a host of discrete distributions. Ve illustrate the general results obtained in case of the geometric distibution.