Optimal maintenance intervals for a multi-component system

In the manufacturing industry, preventive maintenance (PM) is carried out to minimise the probability of plant unexpected breakdown. Planned PM is preferred as disruption to operation is then minimised. Suggested PM intervals are normally prepared by the original equipment manufacturers (OEMs), however due to the multifaceted relationship between operating context and production requirement for different plants, it is unlikely that these suggested intervals as prescribed by the OEMs are optimal. Reliability, budget and breakdown outages cost are some of the critical factors that will affect the calculation of optimal maintenance intervals. Maintenance managers are required to determine optimal maintenance intervals with the above different requirements set by management. In this paper three models are proposed to calculate optimal maintenance intervals for multi-component system in a factory subjected to minimum required reliability, maximum allowable budget and minimum total cost. Numerical examples are provided to illustrate the application and usefulness of the proposed models.     

Iterative Scaling in Curved Exponential Families

The paper describes a generalized iterative proportional fitting procedure that can be used for maximum likelihood estimation in a special class of the general log‐linear model. The models in this class, called relational, apply to multivariate discrete sample spaces that do not necessarily have a Cartesian product structure and may not contain an overall effect. When applied to the cell probabilities, the models without the overall effect are curved exponential families and the values of the sufficient statistics are reproduced by the MLE only up to a constant of proportionality. The paper shows that Iterative Proportional Fitting, Generalized Iterative Scaling, and Improved Iterative Scaling fail to work for such models. The algorithm proposed here is based on iterated Bregman projections. As a by‐product, estimates of the multiplicative parameters are also obtained. An implementation of the algorithm is available as an R‐package.     

Temperature,climate change,and birth weight: evidence from Hungary

Population and Environment - We analyze the impact of in utero temperature exposure on the birth weight and an indicator for low birth weight using administrative data on singleton live births...     

Unconditional respect for persons: A social psychological analysis

It has been suggested that unconditional respect for persons, i.e. respect that is due to everyone simply as a function of their being persons, is the most fundamental kind of respect. Showing unconditional respect towards someone involves recognizing their integrity as a person and their status as an autonomous rational actor. This idea is a cornerstone of much moral, social and political theory. While the idea implicitly underlies some contemporary psychological work on respect, for the most part this fundamental moral orientation has been neglected in psychology. The concept needs clear explication and measurement if its explanatory and predictive value is to be fully realised. This paper will explore the concept of unconditional respect, describe a scale for measuring individual differences in this attitude, and then go on to position unconditional respect, both conceptually and empirically, amongst other relevant social psychological constructs such as Social Dominance Orientation, Right-Wing Authoritarianism, Empathy and Perspective-taking. We then provide some evidence on, as well as speculation about, the role of unconditional respect in interpersonal and intergroup relations. Dr. Tania Tam is a social statistician at the Legal Services Research Centre, London. She has degrees in German and in Psychology from the University of California at Berkeley and a doctorate from the University of Oxford. Her research interests have focussed on intergroup conflict, including issues of respect, forgiveness and trust; and on the effects of communication between grandparents and grandchildren on ageism.     

IS THE ASSUMPTION OF UNIFORM INTRA-CLASS CORRELATION EVER NEEDED?

When modelling a finite population it is sometimes assumed that the residuals from the regression model expectations are distributed with a uniform non-zero intra-class correlation. It is shown that if a certain vector is spanned by the columns of the design matrix (in the homoskedastic case this vector corresponds to the inclusion of a constant term) then such a model is underidentified and the assumption of a known non-zero correlation has almost no impact on the results of the regression analysis. When this vector is not spanned by the columns of the design matrix, a simpler alternative model can usually be fitted equally well to observations from any single population. The only exception occurs when the the intra-class correlation required is negative in sign.     

Comparing the effectiveness of I-BMS-informed self-help interventions in alleviating psychosocial distress for women awaiting the outcome of IVF treatment

Women undergoing in vitro fertilisation experience enormous emotional distress while waiting to find out if they are pregnant; yet their intention to seek help remains low. Interventions that can be easily self-administered may provide a promising alternative. This randomised trial compares psychosocial outcomes of 207 women who received a self-help education booklet containing either spiritually reflective exercise and relaxation techniques, spiritually reflective exercises only, or information about body-mind wellness. Results suggest that knowledge on body-mind wellness protected the women from deteriorating in a range of psychosocial well-being domains that would otherwise have occurred during the waiting period prior to the pregnancy test.     

In the Best Interest of the (Adult) Child: Ideas About Kinship Care of Older Adults

This article uses a qualitative, ethnographic approach to examine the experiences of older adults and their kin, as the older adult engages in relocation. Studies looking at caregiving by kin for older adults highlight burdens for the adult child. This study offers a life course perspective on kinship care, analyzing older adults’ decisions to move. It was found that many older adults are strongly influenced by the desire to not be solely cared for by their kin, as well as to select housing near their existing social network, which might exclude kin. In conclusion, policy implications are discussed.     

Base polyhedra and the linking property

An integer polyhedron \(P \subseteq {\mathbb {R}}^n\) has the linking property if for any \(f \in {\mathbb {Z}}^n\) and \(g \in {\mathbb {Z}}^n\) with \(f \le g\), P has an integer point between f and g if and only if it has both an integer point above f and an integer point below g. We prove that an integer polyhedron in the hyperplane \(\sum _{j=1}^n x_j=\beta \) is a base polyhedron if and only if it has the linking property. The result implies that an integer polyhedron has the strong linking property, as defined in Frank and Király (in: Cook, Lovász, Vygen (eds) Research trends in combinatorial optimization, Springer, Berlin, pp 87–126, 2009), if and only if it is a generalized polymatroid.     

The origins of distant voicing: Examining relational dimensions in public diplomacy and their effects on megaphoning

Extant literature has discussed the similarities between public relations and public diplomacy. This study seeks to contribute to existing research on the application of organization–public relationships (OPR) to public diplomacy by further exploring relational dimensions in public diplomacy and empirically testing them based on a model consisting of antecedents (i.e., political, economic, interpersonal, cultural and corporate interactions), relational dimensions (i.e., interactional bilateralism, power mutuality, trust, empathy, relational satisfaction, relational continuation, relational attentiveness and relational curiosity), and consequences (i.e., positive and negative megaphoning). A total of 490 respondents from the United States were recruited on Amazon M-Turk to respond to survey items regarding China and Mexico. Confirmatory factor analysis and regression analysis were conducted. The findings indicate: (a) positive associations between the antecedents and the relational dimensions, (b) positive associations between the relational dimensions and positive megaphoning, and (c) negative associations between the relational dimensions and negative megaphoning. (148 words)