The effect of shiftwork related fatigue on the family life of train operators: implications for safety and health professionals

Drawing upon an original research study about the effects of fatigue on train operators, the present article focuses upon family issues as having the most significant impact on the participants. Family support, for example, represents an important mechanism for managing and coping with fatigue. Family support comprises understanding of the physiological and emotional issues surrounding shiftwork and erratic work schedules. This article explores the impact of fatigue upon a variety of family and relational issues. This inquiry describes the impact of family on the broader employee view of managing fatigue that considers such comprehensive issues as perception of the work environment, emotional stability, personal control concerns and other positive attributes. These issues ultimately impact the health, productivity and performance of employees. Final discussion includes implications for workplace application of the research findings.     

Construction of orthogonal Latin hypercube designs with flexible run sizes

Latin hypercube designs (LHDs) have recently found wide applications in computer experiments. A number of methods have been proposed to construct LHDs with orthogonality among main-effects. When second-order effects are present, it is desirable that an orthogonal LHD satisfies the property that the sum of elementwise products of any three columns (whether distinct or not) is 0. The orthogonal LHDs constructed by Ye (1998), Cioppa and Lucas (2007), Sun et al. (2009) and Georgiou (2009) all have this property. However, the run size n of any design in the former three references must be a power of two (n=2^c) or a power of two plus one (n=2^c+1), which is a rather severe restriction. In this paper, we construct orthogonal LHDs with more flexible run sizes which also have the property that the sum of elementwise product of any three columns is 0. Further, we compare the proposed designs with some existing orthogonal LHDs, and prove that any orthogonal LHD with this property, including the proposed orthogonal LHD, is optimal in the sense of having the minimum values of ave(|t|), t_max, ave(|q|) and q_max.     

Toward a Theory of Community Conflict: Factors Influencing the Initiation and Scope of Conflict*

A theory of the structure and process of community conflict is developed around concepts used in earlier works in the field. Then propositions relating to the central elements of community conflict are presented by concentrating on the primary variable: scope. Propositions constructed with other relevant structural variables are introduced. To begin with, procedures used in developing the propositions are discussed; and, then, suggestions for measuring them are given. Finally, implications of the theory in analyses of change are discussed.