Integration of time as a factor in ergonomic simulation

The paper describes the application of a simulation based ergonomic evaluation. Within a pilot project, the algorithms of the screening method of the European Assembly Worksheet were transferred into an existing digital human model. Movement data was recorded with an especially developed hybrid Motion Capturing system. A prototype of the system was built and is currently being tested at the Volkswagen Group. First results showed the feasibility of the simulation based ergonomic evaluation with Motion Capturing.     

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.     

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.     

Revenue Mobilisation in Sub‐Saharan Africa: Challenges from Globalisation I – Trade Reform

This is the first of two articles evaluating the nature and extent of, and possible responses to, two of the central challenges that globalisation poses for revenue mobilisation in sub‐Saharan Africa: trade liberalisation, and corporate tax competition. Both articles use a new dataset with the features needed to address these issues meaningfully: a disentangling of tariff from commodity tax revenue, and a distinction between resource‐related and other revenues. This first article describes that dataset, and provides a broad picture of revenue developments in the region between 1980 and 2005. Countries’ experiences have varied, but the overall picture is of non‐resource revenues having been essentially stagnant. Within this, however, and with exceptions, reductions in trade tax revenue have been largely offset by increased revenue from domestic sources.     

Brown rats (<Emphasis Type="Italic">Rattus norvegicus</Emphasis>) in urban ecosystems: are the constraints related to fieldwork a limit to their study?

Nowadays, the majority of human beings live in urban ecosystems, with this proportion expected to continue increasing in the future. With the growing importance of urban rat-associated issues (e.g. damages to urban infrastructures, costs of rat-control programs, rat-associated health risks), it is becoming indispensable to fill the identified gaps in knowledge on the urban brown rat regarding, among others, its density, home range, genetic structure, and infectious status. In this context, live-trapping is a crucial prerequisite to any scientific investigation. This paper assesses the main constraints and challenges regarding the urban field and describes the major steps to be considered when planning research on urban rats. The primary challenges are i) the characterization of the urban experimental unit; ii) the choice of a trapping design: the use of live-trapping in capture-mark-recapture design, in association with modern statistics, is highly recommended to answer ecological questions (although these methods, mostly developed in natural ecosystems, need to be implemented for the urban field); iii) the potential ethical considerations with regard to animal welfare and field-worker safety; iv) the building of mutually-beneficial collaborations with city stakeholders, pest control professionals, and citizens. Emphasis must be put on communication to the public and education of field-workers. One major need of modern urban rat research is a peer-validated field methodology allowing reproducibility, repeatability, and inference from urban field studies and enabling researchers to answer long-standing key questions about urban rat ecology.     

Data depth and correlation

Summary: We describe depth–based graphical displays that show the interdependence of multivariate distributions. The plots involve one–dimensional curves or bivariate scatterplots, so they are easier to interpret than correlation matrices. The correlation curve, modelled on the scale curve of Liu et al. (1999), compares the volume of the observed central regions with the volume under independence. The correlation DD–plot is the scatterplot of depth values under a reference distribution against depth values under independence. The area of the plot gives a measure of distance from independence. Correlation curve and DD-plot require an independence model as a baseline: Besides classical parametric specifications, a nonparametric estimator, derived from the randomization principle, is used. Combining data depth and the notion of quadrant dependence, quadrant correlation trajectories are obtained which allow simultaneous representation of subsets of variables. The properties of the plots for the multivariate normal distribution are investigated. Some real data examples are illustrated. *This work was completed with the support of Ca Foscari University.     

An immune algorithm with stochastic aging and kullback entropy for the chromatic number problem

We present a new Immune Algorithm, IMMALG, that incorporates a Stochastic Aging operator and a simple local search procedure to improve the overall performances in tackling the chromatic number problem (CNP) instances. We characterize the algorithm and set its parameters in terms of Kullback Entropy. Experiments will show that the IA we propose is very competitive with the state-of-art evolutionary algorithms.