A special combinatorial problem: pitch arrangement for pneumatic tires

In this paper, we introduce a combinatorial problem faced in the tire industry and then define it and optimize it by tabu search from the perspective of operational research. Such a problem is termed the pitch arrangement problem and involves both selecting and sequencing problems along with noninteger design variables. Pitch arrangement is an essential procedure for tires before their manufacture. Using this procedure, engineers have to choose an optimal groove distribution on tire treads for the purpose of manufacturing low-noise tires. Most research works on pitch arrangement are supported by tire companies, and their results are patented instead of being published. In this study, we define the abovementioned problem clearly and optimize it by tabu search. Two actual manufactured tires are chosen for the case studies. In addition, two patents and two types of pitch sequences optimized by genetic algorithms are also applied to these two tires for comparison. The pitch arrangement is optimized successfully and the performance of tabu search is found to be outstanding.     

Editorial

Ohne Zusammenfassung     

The Collapsing Choice Theory: Dissociating Choice and Judgment in Decision Making

Decision making theory in general, and mental models in particular, associate judgment and choice. Decision choice follows probability estimates and errors in choice derive mainly from errors in judgment. In the studies reported here we use the Monty Hall dilemma to illustrate that judgment and choice do not always go together, and that such a dissociation can lead to better decision-making. Specifically, we demonstrate that in certain decision problems, exceeding working memory limitations can actually improve decision choice. We show across four experiments that increasing the number of choice alternatives forces people to collapse choices together, resulting in better decision-making. While choice performance improves, probability judgments do not change, thus demonstrating an important dissociation between choice and probability judgments. We propose the Collapsing Choice Theory (CCT) which explains how working memory capacity, probability estimation, choice alternatives, judgment, and regret all interact and effect decision quality.      

Asymmetries in Information Processing in a Decision Theory Framework

Research in psychology suggests that some individuals are more sensitive to positive than to negative information while others are more sensitive to negative rather than positive information. I take these cognitive positive–negative asymmetries in information processing to a Bayesian decision-theory model and explore its consequences in terms of decisions and payoffs. I show that in monotone decision problems economic agents with more positive-responsive information structures are always better off, ex ante, when they face problems where payoffs are relatively more sensitive to the action chosen when the state of nature is favorable.      

A Comparison of Ambient Casino Sound and Music: Effects on Dissociation and on Perceptions of Elapsed Time While Playing Slot Machines

This research examined the effects of a casino’s auditory character on estimates of elapsed time while gambling. More specifically, this study varied whether the sound heard while gambling was ambient casino sound alone or ambient casino sound accompanied by music. The tempo and volume of both the music and ambient sound were varied to manipulate temporal engagement and introspection. One hundred and sixty (males = 91) individuals played slot machines in groups of 5–8, after which they provided estimates of elapsed time. The findings showed that the typical ambient casino auditive environment, which characterizes the majority of gaming venues, promotes understated estimates of elapsed duration of play. In contrast, when music is introduced into the ambient casino environment, it appears to provide a cue of interval from which players can more accurately reconstruct elapsed duration of play. This is particularly the case when the tempo of the music is slow and the volume is high. Moreover, the confidence with which time estimates are held (as reflected by latency of response) is higher in an auditive environment with music than in an environment that is comprised of ambient casino sounds alone. Implications for casino management are discussed.     

Board size and corporate performance: the missing role of board leadership structure

Different arguments have been introduced in the literature both for and against large and small board sizes. In this context, empirical evidence regarding the impact of board size on corporate performance is less conclusive, which means that further study is needed. Contrary to previous work, it is hypothesized in this study that the relationship between board size and corporate performance is more likely to be confounded by board leadership structure. Econometric analysis provided strong evidence for the applicability of this hypothesis and demonstrated that board size positively affects corporate performance in the presence of CEO non-duality (board leadership structure that is split between the roles of the CEO and the roles of the chairman). Furthermore, board size is shown to have a negative influence on corporate performance in the presence of CEO duality (board leadership structure that assigns the roles of both CEO and chairman to the same person). This conclusion is robust to the use of different measures of corporate performance, control variables and econometric models. Thus, these findings cast doubt on most of the existing evidence that posits that either large or small board size is always the best alternative to be followed in all organizations.     

Clinical Assessment of Canadian Military Marriages

This theoretical discussion shed lights on the elements that impact on Canadian military marriages. A case example is presented to illustrate the value of using the strengths perspective, systems theory and attachment theory when assessing couples in this group. It further demonstrates how different assessment approaches produce significantly varied treatment plans.     

More on the stable,generalized stable,absorbing and admissible sets

We show the necessary and sufficient conditions for any two of the sets of stable, generalized stable, absorbing or admissible sets of an abstract decision problem to coincide. We show that all these conditions can be written as depending only on the number of predecessors or successors of some alternatives.     

Reflections on the Work of Professor Selma Fraiberg

This paper reviews the work of Professor Selma Fraiberg who became a leading figure in the field of infant mental health. Born in 1918 she first received an MSW in Social Work and then undertook her Analytic Training in Detroit Michigan. While she maintained her identity as a social worker throughout her life, she integrated insights from the fields of social work, psychoanalysis and developmental and ego psychology in her research and practice. This paper traces her development as a clinician, researcher, and educator. Three cases describe her ability to integrate social work methodologies with analytic insights. The cases describe the treatment of a latency age child at a time of social change, a clinical research study of the developmental risk of children blind from birth, and a groundbreaking study in the field of infant mental health. Her study of infants at developmental risk focused on the parent /infant relationship and parents were included in the treatment process so that they could become more attuned to their young child. Her work highlighted the intergenerational issues that shaped the parental capacity for empathic nurturance between parent and child. The article Ghosts in the Nursery incorporated the major theoretical concepts of the new theoretical approach to treatment and is still much read in graduate programs today. Although extensive new research has added to the field of infant mental health, her contributions are still relevant to research and practice today.