Geometric rounding: a dependent randomized rounding scheme

We develop a new dependent randomized rounding method for approximation of a number of optimization problems with integral assignment constraints. The core of the method is a simple, intuitive, and computationally efficient geometric rounding that simultaneously rounds multiple points in a multi-dimensional simplex to its vertices. Using this method we obtain in a systematic way known as well as new results for the hub location, metric labeling, winner determination and consistent labeling problems. A comprehensive comparison to the dependent randomized rounding method developed by Kleinberg and Tardos (J. ACM 49(5):616–639, 2002) and its variants is also conducted. Overall, our geometric rounding provides a simple and effective alternative for rounding various integer optimization problems.     

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.     

The role,power and influence of company chairs

This paper develops an analytical framework to depict the heterogeneity that characterises the role of board chair and demonstrate the potential variability in how chairs operate boards and exercise power and influence on strategy, control and resource related tasks at board level. Theories of power and influence, as applied to top management teams and boards of directors, are explicated within the context of contemporary governance practices that are establishing the role of the board chair as distinct to that of the chief executive officer. Specifically, the paper maps sources of power and varying contemporary chair practices, including chair nomenclature (i.e. executive vs. non-executive chairs), chair origin (insider vs. outsider) and chair time (full-time vs. part-time). A number of theoretical chair-power models emerge from this analysis and are subject to empirical analysis using data collected from 160 chairs of 500 FTSE-listed companies. Theoretically and empirically, the paper complements structural approaches to studying boards with attention to behaviour on boards. By linking board structure, board process and the exercise of influence, the study reveals both differences amongst chairs in how they run the board, but also that chairs’ differ in the influence they exert on board-related tasks. Full-time executive chairs exert their greatest influence in strategy and resource dependence tasks whereas part-time, non-executive chairs seem to exert more influence over monitoring and control tasks.     

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.     

Sociotropic Concerns and Support for Counterterrorism Policies*

Objective. An individual's personal experiences and perception of the collective experience are often linked to political attitudes, especially those concerning the national economy. In this article, we examine whether personal concern about terrorism and perceptions of public concern about terrorism affect attitudes about counterterrorism policies. In addition, we evaluate which factor is the strongest predictor across several counterterrorism policies. Method. We analyze individual‐level survey data collected during the fall of 2001. Results. Our results indicate that perceptions of public concerns are the strongest and most consistent predictor of policy attitudes about terrorism. Conclusion. The implications for theory about perceptions of public opinion and the competing role of personal interest and sociotropic concern are discussed.     

Work and Care Strategies of European Families: Similarities or National Differences?

This paper examines the work and care strategies chosen by full‐time working families with children in Finland, Italy, Portugal and the UK. It asks whether European families in different countries, facing the same problems of balancing employment and childcare responsibilities, respond to their situations in similar ways. An increase in dual‐earner families where both parents work full‐time represents a general employment trend in today's Europe. Also, within families with children, such employment patterns are now more common than they were previously. National differences may therefore not any longer be as marked as often indicated by country‐based surveys. The qualitative data from the SOCCARE Project offer a way to examine this issue. The focal point of the paper is to make a comparative analysis of couples in similar work and care situations. Using their working hours as the common denominator, this paper analyses their daily childcare arrangements and how these are impacted by gender roles, working schedules, flexibility of workplace, income levels, parents’ educational background and availability of care facilities. The paper concludes that European families’ work and care strategies have many similarities whereby national differences may not be as marked as often indicated by contemporary research.     

Experiential design and religious publicity at D.C.’s Museum of the Bible

ABSTRACT

This article examines the sensory dimension of religious publicity, focused on the case of an evangelical museum in the United States. Washington D.C.’s Museum of the Bible (MOTB) was envisioned and funded primarily by conservative Protestants, and is a revealing case of religion in public life because most of the creative labor of design was conceived and executed by secular firms who do not typically work for faith-based clients. The professional expertise of these firms, “experiential design,” informs a sea change in contemporary museology and the expansion of the experience economy in late modernity. Ultimately, I argue that MOTB’s engagement with experiential design indexes the power of entertainment in late modern life, as the sensory repertoire at play operates with largely unquestioned legitimacy and presumed efficacy. By mobilizing the cultural capital of design, an evangelical museum makes a claim for diverse audiences in a deeply public setting.     

The Effect of Infancy Childcare Center Use and Maternal Employment on Toddlers’ Language Development in South Korea

Using first to fourth wave data of the Panel Study of Korean Children (PSKC), this study explores the effects of childcare center use, maternal employment, and other child and familial characteristics on the language development of toddlers in Korea. Among the 2078 families with children in the PSKC, those who completed the Receptive and Expressive Vocabulary Test at the fourth wave were selected, and a small number of disabled or prematurely born children were excluded. In addition, to clarify the effects of maternal employment, families with mothers who were either employed or unemployed for three consecutive years during the child's infancy were selected. Regression analysis showed that neither childcare center use nor maternal employment during infancy had significant effects on toddlers’ expressive and receptive vocabulary at the fourth wave. Family characteristics, such as household poverty and maternal education level, as well as child characteristics, such as gender and birth order, had significant effects on expressed vocabulary. However, only children's gender significantly affected the receptive vocabulary level of toddlers.