A new skew-bimodal distribution with applications

The modeling and analysis of experiments is an important aspect of statistical work in a wide variety of scientific and technological fields. We introduce and study the odd log-logistic skew-normal model, which can be interpreted as a generalization of the skew-normal distribution. The new distribution can be used effectively in the analysis of experiments data since it accommodates unimodal, bimodal, symmetric, bimodal and right-skewed, and bimodal and left-skewed density function depending on the parameter values. We illustrate the importance of the new model by means of three real data sets in analysis of experiments.     

The development of global IT infrastructure

A research model of the impact of a multinational corporations’ (MNC) global strategic orientation on global IT infrastructure was developed using global integration, or the degree to which a global strategy is actually implemented, as a mediator. A “matched pair” survey of 94 MNCs was conducted (two respondents per firm) in order to guard against common source bias. The results showed that the firms that pursue a globally oriented strategy actually enacted these strategies as indicated by a wide-variety of resource flows across national units. The role of the level of global integration as a mediator between global strategic orientation and global IT capabilities was empirically demonstrated. This confirms that a global strategy is not sufficient to ensure that an enabling IT infrastructure will be developed; rather it is the actual level of integration and interdependence that is achieved as a result of the strategy that drives IT infrastructure. The primary areas in which global integration was found to be closely linked to the global IT infrastructure were human resources, which significantly influenced the reach, range, support services and planning of the global IT infrastructure, and information resources which significantly influenced the planning dimension of the infrastructure. These results strongly suggest that the transfer of people among national units creates an information needs “pull” which leads to the development of better IT infrastructure and that the “push” of standardized information also contributes positively.     

The effects of board size and ‘busy’ directors on the market value of Italian companies

This paper presents evidence that corporate governance quality measured by (1) the board size and (2) the fraction of directors that serve on more corporate boards, influences the market value of firms. The analysis is based in Italy, a country that is characterized by family and concentrated ownership, low legal protection of investors and pyramidal firm structures. Our empirical results suggest that the level of ‘busy-ness’ of corporate directors as a measure of board effectiveness has a significant influence on firm’s market performance. By contrast, we find limited evidence that board size has a substantial impact on the market valuation, except in small and medium enterprises and in some specific industry sectors.

Approximate inference in heteroskedastic regressions: A numerical evaluation

The commonly made assumption that all stochastic error terms in the linear regression model share the same variance (homoskedasticity) is oftentimes violated in practical applications, especially when they are based on cross-sectional data. As a precaution, a number of practitioners choose to base inference on the parameters that index the model on tests whose statistics employ asymptotically correct standard errors, i.e. standard errors that are asymptotically valid whether or not the errors are homoskedastic. In this paper, we use numerical integration methods to evaluate the finite-sample performance of tests based on different (alternative) heteroskedasticity-consistent standard errors. Emphasis is placed on a few recently proposed heteroskedasticity-consistent covariance matrix estimators. Overall, the results favor the HC4 and HC5 heteroskedasticity-robust standard errors. We also consider the use of restricted residuals when constructing asymptotically valid standard errors. Our results show that the only test that clearly benefits from such a strategy is the HC0 test.     

The Sex Check: The Development of an HIV-Prevention Service to Address the Needs of Latino MSM

The Sex Check is a brief, telephone-delivered, HIV-prevention intervention tailored for individuals who are at high risk of HIV infection or transmission but who are neither reducing their risk on their own nor seeking support for this purpose. Because the intervention is delivered on a one-to-one basis, permits anonymity, is marketed to "men who have sex with men," and is brief, it may be particularly responsive to cultural, structural, and attitudinal barriers to serving Latino MSM. Because many Latino MSM continue to engage in high risk sexual behaviors, developing and testing prevention interventions with this population is a public health priority.     

基于供应链的协同生产调度研究

基于供应链环境下的两层多代理系统( MAS)体系结构模型,考虑了粗粒度和细粒度的信息处理需要,进一步细分了企业级各 Agent 和车间级各 Agent 之间的任务和协作。这种松耦合、分布式动态调度的控制结构很好地适应了供应链环境下企业之间以及企业内部车间生产制造单元之间的分布自治、协同合作的特性,为解决供应链环境下企业之间以及企业内部各个车间的动态分布问题提供了一个可操作的体系架构模型和技术基础,可解决企业在供应链环境下的动态调度以及调动优化问题。     

The Difficulties of Interculturalism

One can describe three hurdles on the road to building a multi‐ethnic society: under‐estimating the problem; the conflict between the need to respect a culture and the need to open it to another culture; the existence of unacceptable aspects of a specific culture in a universalistic framework. The article describes ways to overcome these difficulties: (a) a gradual process from multiculturalism towards interculturalism; (b) certain minimum conditions must be met at the material level (home, work, etc); (c) to encourage individuals and communities to lessen their physical and psychological distance and to show each other mutual respect (to which education can provide a contribution through the teaching of social sciences).     

Cost-Effectiveness of Risk-Reduction Measures from a National Viewpoint: A Case Study of the Angra Nuclear Plant in Brazil

In this paper a systemic or national approach to cost-effectiveness analysis of risk-reduction measures is reviewed, and its advantages and limitations are discussed. The method is applied to the problem of the cost-effectiveness of increasing the Angra 3 NPP containment wall thickness from the present 60 cm to 180 cm thick in order to prevent damage to the reactor core in case of a direct commercial aircraft crash on it. It is concluded that this measure is not cost-effective if the referred approach is considered.