Mortality in Ghana: Evidence from the cape coast project data

This paper deals with the estimation of mortality for a rural community of about 20,000 persons in the rain-forest area of south-west Ghana. Specifically, infant, child and adult mortality estimates have been obtained by the application of a wide range of direct and indirect methods of measuring mortality from the different statistics collected by a longitudinal mortality and fertility project conducted during 1974–7. It was noted that infant and childhood mortality rates obtained from death registrations were consistent with those rates yielded by pregnancy histories and child survival statistics. However, the adult mortality estimates derived from orphanhood statistics tended to be lower than those suggested by death registrations. The analysis revealed an infant mortality rate of 100 for boys and 84 for girls, equal childhood mortality rates for boys and girls (85–6), a lower expectation of life at birth for men (45.8 years) than for women (52.8), and a much more severe incidence of mortality among men aged over 40 than for women at the corresponding ages.     

A mathematical model of a population genetics: Effects of genetic variation on homosexuality

This study deals with simple mathematical models for the purpose of generating testable prediction in genetics. The genetic effects in human population are because of the following four factors, (i) paternal, (ii) maternal, (iii) environmental and (iv) idiopathic. For the measurement of genetic characteristics, the environment also plays an important role. In the present paper we analyze this linkage for homosexuality for the first three factors because the fourth one affects a very little population. This study provides genetics and evolutionary basis for making generating testable predictions specifically where the environmental factors affect the characteristics of genes which also influence homosexuality. The effect of environment on homosexuality is highlighted because earlier studies confined only up to the paternal and maternal linkages. We consider two types of selections (i) direct selection with environmental effects (ii) combined selection with direct, maternal and environmental effects. The objective of this investigation is to provide the conditions for the maintenance of genetic variation of genotype of male and female. We concentrate on highlighting homosexuality as a result of variation in genes. Numerical results are obtained by taking illustration. The sensitivity analysis is carried out to explore homosexuality in terms of fitness loss and fitness gain.     

On Gini's diversity measure

The purpose of this paper is to investigate the optimal properties of Gini's diversity measure. It is shown that as number of species increase , Gini's diversity approaches asymptotically to unity.     

Tests for bivariate mean residual life

In this paper we have developed tests for bivariate exponentiaIity against the ‘bivariate decreasing mean residual life (BDMRL)’ and ‘bivariate new better than used in expectation (BNBUE)’ classes of non-exponentia1 probability distributions. We have also obtained a large-sample approximation to make the test readily applicable.     

Test for comparing complete expectations of life of two groups

Abstract

Complete expectation of life of an individual gives an intuitive and interesting perspective on the ageing process and is an important concept in the insurance sector for determination of premium. We propose a new test for testing equality of complete expectations of life of two groups/populations. Power of the new test is calculated through simulations and compared with the power of the tests given by Berger, Boos, and Guess (1988 Berger, R. L., D. D. Boos, and F. M. Guess. 1988. Tests and confidence sets for comparing two mean residual life functions. Biometrics 44 (1):103–15.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and Aly (1997 Aly, E. E. A. A. 1997. Nonparametric tests for comparing two mean residual life functions. Lifetime Data Analysis 3 (4):353–66.[Crossref], [PubMed] , [Google Scholar]). It is observed that the proposed test statistic is more powerful than the competing tests for the cases considered in this paper. A real life illustration is included.     

A Selection Procedure for Selecting the Least Increasing Failure Rate Average Distribution

For k independent absolutely continuous increasing failure rate average (IFRA) life distributions F_i, i = 1, 2, …, k, Link (1989 Link, W.A. (1989). Testing for exponentiality against monotone failure rate average alternatives. Commun. Statist. Theor. Meth. 18(8): 3009–3017.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) considered a measure of departure of against monotone failure rate average alternatives. In this paper, we use the measure defined by Link for detection of IFRA-ness of life distribution F_i. A two-stage selection procedure to select the least IFRA distribution is proposed. This selection procedure is based on a U-statistic which is an estimator of the measure and can be implemented even when the IFRA life distributions belong to different families. The applications of this procedure are discussed for some well known distributions.     

Decision support tool for lean product and process development

Lean and concurrent engineering (CE) are widely acknowledged business process improvement strategies. These strategies can improve processes, reduce costs, and cut waste enabling organisations to remain competitive. Lean manufacturing offers an enterprise-wide methodology that improves reliability and flexibility while reducing lead-times and inventory carrying costs. Companies in manufacturing and service sectors are focusing on integrating lean manufacturing methodology with other applications, so that, all their systems and processes are aligned. This article proposes a CE framework based on application of information technology and object-oriented methodology for lean manufacturing. This approach expected to give manufacturing companies an extra edge in today's competitive market. A case study is presented in this article to demonstrate the effectiveness of CE framework in a machine tool manufacturing company. CE practice was adopted for new products, to align the systems and processes of the company. Product development lead-time was found to decrease by more than 50% compared to similar development projects carried out by the company. The need for rework was found to be negligible and the development cost was reduced considerably.     

Fertility of Australian birth cohorts: Components and differentials

The paper examines the change in the level and pattern of fertility that took place in the post-1971 period, and the downward completed fertility of successive generations of Australian women born since 1933–37. The change in cohort fertility is assessed in terms of the cohort parity progression ratios, and the four components of cohort total fertility: the proportion of women who proceeded to have a birth, mean age at first birth, mean age at last birth, and average interbirth interval for women who had at least two births. The other aspects discussed are the cohort fertility differentials and the implications of the current trends for future fertility in Australia.     

On the adoption of lean manufacturing principles in process industries

Traditionally, the lean paradigm has been applied to discrete manufacturing of items that can be easily put together and taken apart. The process industry, on the other hand, transforms raw materials into cohesive units that are basically blended into a final product with parts that cannot be disassembled and then reassembled. The current lean literature provides numerous commendable examples of theory and practices of lean principles in discrete manufacturing. However, its application in process industry is limited. Furthermore, there is no systematic accounting of the lean literature in this sector, which may have contributed to lesser awareness in the industry. This paper provides a state-of-the-art review of lean manufacturing literature with respect to its applications in process industry. It contributes to the classification of literature in a manner which helps to identify strategies suitable for the adoption of lean concepts in process industry. The paper seeks to synthesise the literature with an emphasis on identifying the scope for lean in process industry and associated benefits. The review also presents an analysis of the lean tools and techniques that have been applied or have potential application in the process industry and the challenges to implement lean. We believe that such a comprehensive review will not only facilitate the adoption of lean in process industry but will also provide agenda for further research by exposing voids in the knowledge base.