Application of a non-homogeneous Markov chain with seasonal transition probabilities to ozone data

In this work, we assume that the sequence recording whether or not an ozone exceedance of an environmental threshold has occurred in a given day is ruled by a non-homogeneous Markov chain of order one. In order to account for the possible presence of cycles in the empirical transition probabilities, a parametric form incorporating seasonal components is considered. Results show that even though some covariates (namely, relative humidity and temperature) are not included explicitly in the model, their influence is captured in the behavior of the transition probabilities. Parameters are estimated using the Bayesian point of view via Markov chain Monte Carlo algorithms. The model is applied to ozone data obtained from the monitoring network of Mexico City, Mexico. An analysis of how the methodology could be used as an aid in the decision-making is also given.     

Human Error in Autonomous Underwater Vehicle Deployment: A System Dynamics Approach

The use of autonomous underwater vehicles (AUVs) for various applications have grown with maturing technology and improved accessibility. The deployment of AUVs for under-ice marine science research in the Antarctic is one such example. However, a higher risk of AUV loss is present during such endeavors due to the extremities in the Antarctic. A thorough analysis of risks is therefore crucial for formulating effective risk control policies and achieving a lower risk of loss. Existing risk analysis approaches focused predominantly on the technical aspects, as well as identifying static cause and effect relationships in the chain of events leading to AUV loss. Comparatively, the complex interrelationships between risk variables and other aspects of risk such as human errors have received much lesser attention. In this article, a systems-based risk analysis framework facilitated by system dynamics methodology is proposed to overcome existing shortfalls. To demonstrate usefulness of the framework, it is applied on an actual AUV program to examine the occurrence of human error during Antarctic deployment. Simulation of the resultant risk model showed an overall decline in human error incident rate with the increase in experience of the AUV team. Scenario analysis based on the example provided policy recommendations in areas of training, practice runs, recruitment policy, and setting of risk tolerance level. The proposed risk analysis framework is pragmatically useful for risk analysis of future AUV programs to ensure the sustainability of operations, facilitating both better control and monitoring of risk.     

Slashed power-Lindley distribution

In this article, we introduce the slashed power-Lindley distribution. This model can be seen as an extension of the power-Lindley distribution with more flexibility in terms of the kurtosis of distribution. It arises as the ratio of two independent random variables, the one being a power-Lindley distribution and a power of the uniform distribution. We present properties and carry out estimates of the model parameters by the maximum likelihood method. Finally, we conduct a small simulation study to evaluate the performance of maximum likelihood estimators and we analyze a real data set to illustrate the usefulness of the new model.     

The Role of the State in Explaining the Internationalization of Emerging Market Enterprises

While the competitive advantages of firms from developed economies are well understood, knowledge of the advantages that enable emerging market enterprises (EMEs) to expand overseas remains limited. Our analysis goes beyond theorizing that focuses on firm resources, enhancing the understanding of how EMEs expand abroad by internalizing home‐country institutional advantages that extend beyond the firm boundaries. More specifically, we examine how the state and institutional idiosyncrasies in the home country help EMEs internationalize. We demonstrate that state ownership has a strong independent effect on the international expansion of EMEs. This effect, however, is contingent upon firms' own resources and other location‐ and industry‐specific forces pertaining to the market orientation of each subnational region and the institutional policies within a given industry.     

Some implications of common consequences in lotteries

This work studies the implications of some aspects of preferences toward risk in the choice between two binary lotteries exhibiting a common consequence. The results obtained are then applied to two different problems: the choice between two risky challenges characterized by different rewards in the case of success and different probabilities of success and the choice between self-protection and self-insurance in the presence of the risk of incurring financial loss.

     

ECONOMIC DETERMINANTS OF THE TIMING OF PREFERENTIAL TRADE AGREEMENT FORMATIONS AND ENLARGEMENTS

Preferential trade agreements (PTAs) have proliferated over the past 60 years. While a small number of recent studies have examined empirically the economic determinants of the likelihood of a pair of countries having a PTA, this study explains empirically the timing of all PTA formations and enlargements from 1950 through 2006 using duration analysis. Our main and novel goal is to predict (in‐ and out‐of‐sample) a substantive share of these 1,560 PTA events using a parsimonious model with mainly economic variables, taking selection dynamics into account. Our analysis reveals that we can predict correctly in‐sample the actual year of entry into force for 26% of the 1,560 bilateral PTA formations/enlargements in the period 1950–2006 among 10,518 pairings of 146 countries using only a few economic and political variables. Moreover, we can predict correctly in‐sample 57% of these PTA events within a 10‐year window leading up to the event using this model. The model also performs well out‐of‐sample for the near term (82%), but not if the out‐of‐sample period is very long. We conclude with an evaluation of the model's ability to predict the timing of the North American Free Trade Agreement, the European Union's formation and enlargements, and the model's ten most likely post‐2006 PTA events. (JEL F14, F15)     

Debi Ghate and Richard E. Ralston: Why businessmen need philosophy: the capitalist’s guide to the ideas behind Ayn Rand’s Atlas Shrugged

The essays in this book are meant to serve as an introduction to those ideas of Ayn Rand, which are of particular relevance to business people. Rand was known as a spirited defender of the laissez-faire free enterprise system. It is less commonly known that Rand was also deeply committed to the centrality of the enterprise of philosophy for both public and private life. The essays in this book try to bridge the gap between these two aspects of Rand’s thought. The results of the review of the book are mostly positive. The review attempts to separate the different themes in the book such as the importance of philosophy in general, the importance of philosophy for business, the philosophical defense of the free enterprise system and then to evaluate the evidence and arguments presented by the essayists for each claim.     

The RFad Method--a new fatigue recovery time assessment for industrial activities

This paper presents a study about fatigue recovery time assessment processes in work activities. It came about due to a demand presented by an automotive industry giant, in need of updating existing cycle time sheets and TAKT time parameters. The company decided to hire an Ergonomics Laboratory with ties to a major Brazilian University in order to evaluate current conditions and establish a new method to either calculate recovery times or validate existing assessment criteria, based in the ergonomics evaluation of the work activities. It is clear that there has been evident evolution in the industrial sector in the past two decades. It brought up fast modernization of industrial processes, not only in production but also in terms of management systems. Due to improved computer and robotics systems, combined with overall operational advancements - like the use of lighter hand tools and more effective hoist systems - most work activities have had its physical effort requirements reduced in the past decades. Thus, compensation factors built into production times need to be reviewed in order to avoid unnecessary costs associated to them. By using ergonomics considerations, we prevent simply removing the physical variables built in rest time calculations without taking on account, for example, additional cognitive load represented by the use of more sophisticated pieces of equipment.     

From “dot.org” to “dot.gov”: Professional Crossings in the Brazilian National Policy on HIV/AIDS

This article reflects on the importance of the relations between state and society in policy-making in the area of public health. Several studies in various sectors such as health, education, and social services have made similar observations on organizational dynamics and the institutionalization of different models of partnerships or contracts, often based on the analytical model of three sectors. Individuals and their networks of relationships, however, remain an almost unexplored dimension in these types of research. Against this backdrop, this study seeks to analyze the movement of HIV/AIDS activists to governmental organizations working in this same field. The analysis raises questions concerning the forms of individual and institutional learning that help to maintain the distinct character of innovation of the Brazilian policy. Professionals who cross the borders hold a different profile once they have accumulated experience working with grassroots and local NGOs, and have also had the chance to be trained and enhance their technical and managerial capacities, since the government has supported NGOs for a long period. When combined, these experiences allow them to maintain relationships with social movements and give them the ability to navigate through the government bureaucracy and handle technical information about fighting AIDS epidemics, making it possible for them to negotiate strategic collaborations reflecting the interests of different groups. Hence, they constantly reflect on the differences between government and social spaces, and keep questioning and modifying their roles in the light of potential and existing complementarities.