Application of Multivariate Analysis to Increase the Yield of Dry Cell Batteries

In an organization, the manufacturing process of a dry cell battery was suffering from the problem of frequent stoppages in the assembly line. The complete battery manufacturing operation is highly automated and mechanized. It was suspected that excessive variation in overall height of bobbin was the major reason for such stoppages. The bobbin, the inside part of a dry cell battery acting as cathode, is formed by the battery extrusion process. A planned experiment was carried out on the extrusion process that identified the setting of extrusion machines and the amount of water content in the cathode mixture as the parameters causing variation in the bobbin characteristics. The problem of frequent stoppages was eliminated when appropriate action was taken on these two parameters. Finally, multivariate and univariate control schemes were developed for online control of the bobbin characteristics.     

Union–intersection principle and constrained statistical inference

Most statistical models arising in real life applications as well as in interdisciplinary research are complex in their designs, sampling plans, and associated probability laws, which in turn are often constrained by inequality, order, functional, shape or other restraints. Optimality of conventional likelihood ratio based statistical inference may not be tenable here, although the use of restricted or quasi-likelihood has spurred in such environments. S.N. Roy's ingenious union–intersection principle provides an alternative avenue, often having some computational advantages, increased scope of adaptability, and flexibility beyond conventional likelihood paradigms. This scenario is appraised here with some illustrative examples, and with some interesting problems of inference on stochastic ordering (dominance) in parametric as well as beyond parametric setups.     

Regression models for analyzing clustered binary and continuous outcomes under an assumption of exchangeability

Scientific experiments commonly result in clustered discrete and continuous data. Existing methods for analyzing such data include the use of quasi-likelihood procedures and generalized estimating equations to estimate marginal mean response parameters. In applications to areas such as developmental toxicity studies, where discrete and continuous measurements are recorded on each fetus, or clinical ophthalmologic trials, where different types of observations are made on each eye, the assumption that data within cluster are exchangeable is often very reasonable. We use this assumption to formulate fully parametric regression models for clusters of bivariate data with binary and continuous components. The regression models proposed have marginal interpretations and reproducible model structures. Tractable expressions for likelihood equations are derived and iterative schemes are given for computing efficient estimates (MLEs) of the marginal mean, correlations, variances and higher moments. We demonstrate the use the ‘exchangeable’ procedure with an application to a developmental toxicity study involving fetal weight and malformation data.     

Some remarks on classical and bayesian reliability estimation of binomial and poisson distributions

The problems of estimating the reliability function and Pr{X₁+...+X_k ≤ Y} are considered. The random variables X’s and Y are assumed to follow binomial and Poisson distributions. Classical estimators available in the literature are discussed and Bayes estimators are derived. In order to obtain the estimators of these parametric functions, the basic role is played by the estimators of factorial moments of the two distributions.     

20世纪初俄国在西藏的阴谋

本文引用了丰富的档案和报刊资料,考述了20世纪初英国远征军入侵西藏前后而发生的种种诡秘事件,其中主要涉及两位俄属布里亚特蒙古人,一位是十三世达赖喇嘛的＂洗礼大师＂阿旺·德尔智,另一位是受雇于俄国外交部曾在俄国参谋部中亚探险与情报工作印度小组受过训的泽仁布,他们的神秘使命在于利用其民族和宗教外衣的掩护,达到如何影响达赖喇嘛与英国抗衡目的,从而使俄国能在西藏问题上保持或扩大自己的影响。     

“The Past in the Present: Mills,Tocqueville and the Necessity of History”

Historical sociology has achieved a reasonable degree of respectability in the discipline, and there is much interesting work being produced. But a pronounced aspect of much of this work is an indifference to the question of the value of studying the past as a way to understanding the present. This article argues that, rather than trying to outdo the historians by producing “better,” more theoretically sophisticated history, sociologists would better advance the case for historical sociology by showing how any particular historical study helps illuminate contemporary concerns. The article draws upon the writings of C. Wright Mills and Alexis de Tocqueville to show not just the need for historical sociology but also as indications of how this might best be done.     

Robustness of tests for directional mean

In this paper we study the robustness of the likelihood ratio, circular mean and circular trimmed mean test functionals in the context of tests of hypotheses regarding the mean direction of circular normal and wrapped normal distributions. We compute the level and power breakdown properties of the three test functionals and compare them. We find that the circular trimmed mean test functional has the best robustness properties for both the above-mentioned distributions. The level and power properties of the test statistics corresponding to these functionals are also studied. Two examples with real data are given for illustration. We also consider the problem of testing the mean direction of the von-Mises–Fisher distribution on the unit sphere and explore the robustness properties of the spherical mean direction and likelihood ratio test functionals.     

The Blended Family Life Cycle

Blended families face unique challenges that differ greatly from those encountered by nuclear families. Societal stereotypes that view blended families as abnormal, taking nuclear family functioning as the prototype for all family units, create a lack of role clarity for each of the members involved. Although many strategies exist with which to help families, many are based on nuclear family systems and thus are inapplicable to blended families. The creation of a blended family life cycle specific to blended family systems could help members of a blended family create a successful family unit as they work with a counselor.