Selecting a Good Stochastic System for the Large Number of Alternatives

In this article, we present the problem of selecting a good stochastic system with high probability and minimum total simulation cost when the number of alternatives is very large. We propose a sequential approach that starts with the Ordinal Optimization procedure to select a subset that overlaps with the set of the actual best m% systems with high probability. Then we use Optimal Computing Budget Allocation to allocate the available computing budget in a way that maximizes the Probability of Correct Selection. This is followed by a Subset Selection procedure to get a smaller subset that contains the best system among the subset that is selected before. Finally, the Indifference-Zone procedure is used to select the best system among the survivors in the previous stage. The numerical test involved with all these procedures shows the results for selecting a good stochastic system with high probability and a minimum number of simulation samples, when the number of alternatives is large. The results also show that the proposed approach is able to identify a good system in a very short simulation time.     

One stage multiple comparisons of k-1 treatment mean lifetimes with the control for exponential distributions under heteroscedasticity

Abstract

In survival or reliability data analysis, it is often useful to estimate the quantiles of the lifetime distribution, such as the median time to failure. Different nonparametric methods can construct confidence intervals for the quantiles of the lifetime distributions, some of which are implemented in commonly used statistical software packages. We here investigate the performance of different interval estimation procedures under a variety of settings with different censoring schemes. Our main objectives in this paper are to (i) evaluate the performance of confidence intervals based on the transformation approach commonly used in statistical software, (ii) introduce a new density-estimation-based approach to obtain confidence intervals for survival quantiles, and (iii) compare it with the transformation approach. We provide a comprehensive comparative study and offer some useful practical recommendations based on our results. Some numerical examples are presented to illustrate the methodologies developed.     

An Introduction to Ranking and Selection

This expository paper explains the philosophy of the indifference-zone approach and the subset-selection approach to ranking and selection procedures. It includes examples of operating characteristic curves and data applications for selection problems based on the binomial and normal distributions. A variety of different models and goals are provided with a list of references.     

A statistical test for detecting discordance in rankings between k groups

In several research areas such as psychology, social science, and medicine, studies are conducted in which objects should be ranked by different judges/raters and the concordance of the different rankings is then analyzed. In such studies, it is also frequently of interest to compare the rankings between different groups of judges, e.g. female vs. male judges or judges from different professions. In the two-group case, the two-group concordance test of Schucany & Frawley can be employed for such a comparison. In this article, we propose an extension of this test enabling the comparison of rankings from more than two groups of judges. This test aims to detect disagreement in the average rankings of the objects between k groups with an at least moderate intra-group concordance. We evaluate this test in an extensive simulation study and in an application to data from an aesthetics study. This simulation study shows that the proposed test is able to detect differences between average rankings and performs well even in situations in which the disagreement is comparably small or the intra-group concordance is inhomogeneous.     

提高进城农民购房能力的有效举措——农村宅基地退出与城市购房相挂钩

以人为核心的新型城镇化,关键要解决进城农民在城市的住房问题,因此,创新体制和机制以帮助进城农民在城市拥有自住房,使其真正融入城市、安居乐业,是新型城镇化进程中不可回避的重要现实问题。面对城镇化过程中农民无力购买城市住房而其农村宅基地闲置浪费的现实背景,提出了进城农民宅基地退出与城市购房相挂钩的构想,以期引导进城农民积极有序地退出宅基地,提高农村宅基地的节约和集约利用率,同时解决进城农民的城市住房及房地产库存问题。在界定宅基地退出与城市购房相挂内涵的基础上,提出了解决该问题的具体思路,并剖析了目前面临的三大问题和障碍：第一,进城农民宅基地退出资产的保值增值与收益分配问题;第二,退出的宅基地与期望购买经济适用房所在城市的不一致问题;第三,购买经济适用房面临的支付能力不足问题。最后,针对性提出了通过出租、招拍挂、复垦等途径盘活退出的宅基地资产,实行保障房指标地域政策限制与经济适用房市场交易相结合,合理的宅基地退出补偿标准、住房供应模式创新与土地承包经营权抵押相结合等对策与建议。     

Rejects reduction in a retail bank using Lean Six Sigma

Lean Six Sigma (LSS) is a majestic process improvement methodology that has been proved to be a powerful management strategy across services. The influential synergy of Six Sigma and Lean aims at improving the processes, focusing on both rapid and robust improvements, reducing waste and variation in the process. LSS generates successful results in key performance indicators (KPIs) based environments, where process data gets measured and leveraged for making essential management decisions. The aim of this paper is to highlight the importance of LSS in banking industry through a real-time process improvement study. The article establishes the literature for the need for LSS in banks detailing on customer facing metrics and process KPIs. An action-research study conducted in a retail bank is presented in LSS DMAIC methodology which reaped a benefit of INR 1.6 million and is a classic example of how LSS can bring bottom-line impact to an organisation, alongside contributing to the process improvement mind-set in employees.     

Cumulative patterns of well-being among young social assistance recipients versus other youths

What are the levels of living conditions of young social assistance recipients compared to the youth population at large? This paper investigates living conditions among young social assistance recipients in Norway, compared to a similar age group within the total population. The overall distribution indicates a cumulative rather than compensatory pattern. Social assistance recipients trail behind the population at large across all indicators. They lag more behind the overall population with regard to cumulative levels-of-living scores than with regard to each and every indicator. This lends support to the notion that one should adopt an integrated approach in the treatment of youth living on social assistance, rather than focus on any single issue as “the” problem to assess.     

Establishment of risk acceptance criteria using Life Quality Index: Application to the Indian context

The formulation of risk acceptance criteria may be coupled gainfully with a prediction of the of investment required to comply with it, an exercise which can benefit from the application of socioeconomic indicators. The Life Quality Index (LQI) is one such indicator which amalgamates human mortality and wealth creation and places an implicit economic value on reduction of life risk. While there have been a number of studies to demonstrate the application of LQI pertaining to various technological systems, the present work extends it to estimate the sectoral level investment needed to reduce public risks to within the As Low As Reasonably Predictable region for the chemical industry, with specific illustration of the methodology for India. The potential reduction in public individual risk is computed as a function of percentage increase in safety investment expressed as a fraction of the industry's contribution to the nation's GDP. In addition, using a new, more accurate expression, estimates of a related parameter, the implied cost of averting a fatality (ICAF), are obtained for a number of developed economies and India. The ICAF estimates show reasonable agreement with the value of statistical life (VSL), a parameter which is integral to cost-benefit analysis of safety and environmental regulations.     

中外大学排行榜指标体系和数据来源的比较研究

对中外主要大学排行榜的评价指标按所反映的评价内容进行分类归纳,通过各类指标权重的大小来比较各评价指标体系的不同侧重点,并对由此反映出的中外大学评价指标的差异进行原因分析,从定性与定量相结合的角度为中国大学综合排行榜评价指标体系的设计提供借鉴参考。此外,在对中外大学排行榜评价指标的数据来源进行比较分析的基础上,指出影响大学评价指标设计合理性的主要原因在于数据来源的条件限制,并提出相应的建议。     

Poverty and material deprivation among European workers in times of crisis

Many EU countries are faced with abysmal public debts and high unemployment, and may have to reduce their social expenditure and deregulate their labour market, which should lead to an increase in ‘working poverty’ (i.e., an increase in the number of working men and women who live in a low‐income household, or in a household that cannot afford certain goods and services considered essential for a decent life, respectively). However, working poverty remains an under‐analysed phenomenon in Europe. Moreover, the vast majority of existing definitions used in Europe are based on a relative income poverty line and the EU's official definition of ‘in‐work’, which raises concerns about the robustness of existing findings. This article first examines how the socioeconomic situation has evolved in seven EU Member States that have fared differently. In addition, the article examines whether the use of non‐monetary poverty indicators and of an encompassing definition of ‘working’ has an impact on the conclusions drawn. An attempt is made to identify the main macro‐level determinants of changes in ‘working poverty’ and to better understand their impact at the micro‐level.