Selective Maintenance in System Reliability with Random Costs of Repairing and Replacing the Components

In this paper we consider the problem of determining the optimum number of repairable and replaceable components to maximize a system's reliability when both, the cost of repairing the components and the cost of replacement of components by new ones, are random. We formulate it as a problem of non-linear stochastic programming. The solution is obtained through Chance Constrained programming. We also consider the problem of finding the optimal maintenance cost for a given reliability requirement of the system. The solution is then obtained by using Modified E-model. A numerical example is solved for both the formulations.     

Evaluating the effectiveness of the first breast cancer awareness campaign in the United Arab Emirates: Lessons learned and next steps

Following an innovative breast cancer awareness campaign in the United Arab Emirates, a dual language survey of 500 women and in-depth interviews were conducted. The study found television advertising to be the most optimal awareness communication method, particularly among Emirati and other Arab women respondents. The research also found strong support for a year-long awareness campaign.     

Towards an Objective Classification Scheme for Organizational Task Environments

This study replicates, refines, cross-validates and simplifies a scheme of operationalization and measurement of environmental dimensions proposed by Dess and Beard (1984). Employing a sample of 60 industries and data over a 16-year period, this study found considerable support for the viability of the three dimensions of munificence, dynamism and complexity. The data intensive and computationally complex operationalization scheme was simplified using a discriminant analysis approach and the discriminant functions were cross-validated using an alternate data set.     

Expenditure Differences of University Degree Holders Across Occupational Sectors in Malaysia

This study was motivated by the key role university degree holders play in Malaysia's vision for the future and by concerns expressed about the drift of university degree holders from one sector to another. A questionnaire was mailed to a sample of 400 Malaysian families that had at least one member who held a university degree. The objective was to elicit details of the household economic situation of respondents, with special reference to the differences in expenditure patterns between families whose degree holder worked in higher education, government, or the private sector.Results of tobit analysis of expenditures show that there are some differences between the sectors regarding expenditure patterns, but the differences are not as great as expected. Nevertheless, university-educated persons in the private sector seem to have somewhat different expenditure patterns than their counterparts in other sectors.     

中沙关系回顾与展望

中国和沙特政治制度不同,但两国发展积极友好的关系没有障碍。目前,沙特是中国在西亚和非洲最大的贸易伙伴,两国经贸合作前景广阔。同时,中沙双方均奉行独立自主的外交政策,拥有良好的政治关系,未来在区域组织和联合国等国际舞台上将有更广泛的合作领域。     

The purpose in life and academic behaviour of problem students in Bangladesh

This study was conducted with a group of 30 problem students who have been identified as irregular in class attendence, non-attentive to class lectures, creating disturbances in the class, etc. The problem students were compared with a group of equal number of normal students with respect to a Purpose in Life (PIL) scale. It was found that the problem students had lower scores (M=59.87, SD=18.09) as compared to those of normals (M=87.93, SD=0.68). These scores differed significantly (t=7.230). From this study it was concluded that the problem students demonstrated such activities due to a lack of purpose in their lives, although it was granted that some causality probably runs in both directions. It is hypothesised that counseling may be helpful in order to improve such behaviour.     

Predictive inference for linear and multivariate linear models with ma(1) error processes

The prediction distributions of future responses from the linear and multivariate linear models with errors having a first order moving average (MA(1)) process have been derived. First, we obtained the marginal likelihood function for the moving average parameter 6 and from this likelihood function we estimate the maximum likelihood estimates (MLE) of θ. Using the estimated value θ, we have derived the prediction distributions as well as prediction regions for the future responses. An example has been included.