New Bootstrap Applications in Supervised Learning

Some bootstrap and boosting methods for problems related to classification are introduced in this article. The first method chooses better boosting weights by using a bootstrap search algorithm. The second method is a good way to define a classification frontier. A new formulation for boosting in linear discriminant analysis is given. Since in this new formulation the uncertainty is represented by the weighted covariance matrix, it is more appropriate from the conceptual point of view. Simulation results show that the proposed methods perform well in data analysis.     

Biomechanical strain of goldsmiths

The work of the goldsmiths consists in the manufacture of jewelry. The piece, be it an earring, bracelet or necklace, is hand-assembled. This task requires precision, skill, kindness and patience. In this work, we make use of tools such as cuticle clippers and rounded tip, beads or precious stones and also pieces of metal. This type of activity requires a biomechanical stress of hands and wrists. In order to quantify the biomechanical stress, we performed a case study to measure the movements performed by an assembly of pieces of jewelry. As method for research, filming was done during assembly of parts to a paste, using a Nikon digital camera, for 1 (one) hour. The film was edited by Kinovea software, and the task was divided into cycles, each cycle corresponds to a complete object. In one cycle, there are four two movements of supination and pronation movements of the forearm. The cycle lasts approximately sixteen seconds, totaling 1800 cycles in eight hours. Despite the effort required of the wrists, the activity shows no complaints from the employees, but this fact does not mischaracterizes the ability of employees to acquire repetitive strain injuries and work-related musculoskeletal disorders.     

Production layout improvement in emergency services: a participatory approach

Volunteer fire department is a service that responds emergency situations in places where there are no military emergency services. These services need to respond quickly, because time is often responsible for the operation success besides work environment and setup time interfere with the prompt response to these calls and care efficiency. The layout design is one factor that interferes with the quick setup. In this case, the spaces arrangement can result in excessive or unnecessary movements; also the equipment provision may hinder the selection and collection of these or even create movement barriers for the workers. This work created a new layout for the emergency assistance service, considering the human factors related to work through the task analysis and workers participation on the alternatives of improvement. The results showed an alternate layout with corridors and minimization of unusable sites, allowing greater flexibility and new possibilities of requirements.     

Using remote sensing and census tract data to improve representation of population spatial distribution: case studies in the Brazilian Amazon

This work proposes a methodological approach to redistribute population data obtained from polygonal census tracts into population density surfaces (grids) based on a cell space database. The methodology was first developed for the municipality of Marabá, Pará state, in the Brazilian Amazon. We used a dasymetric method to eliminate areas of environmental restriction to human presence; then integrated environmental data indicative of human presence to generate a potential surface of population occurrence; and finally, census population count data were redistributed into cells. The methodology was subsequently adapted for 13 municipalities of the Sustainable Forests District (SFD) of BR-163, generating population distribution surfaces for 2000 and 2007. The evolution of the resident population over the SFD-BR163 showed spatial patterns compatible with the occupation process described in the literature and verified by fieldwork. To be applied over other areas, the proposed methodology must be adapted with local parameters but in this way, population density surfaces can be useful as an additional data source to study population and environment relationships.     

Detecting influential observations in Watson data

A method for detecting outliers in axial data has been proposed by Best and Fisher (1986 Best, D.J., Fisher, N.I. (1986). Goodness-of-fit and discordancy tests for samples from the Watson distribution on the sphere. Aust. J. Stat. 28:13–31.[Crossref] , [Google Scholar]). For extending that work, we propose four new methods. Two of them are suitable for outlier detection and they depend on the classic geodesic distance and a modified version of this distance. The other two procedures, which are designed for influential observation detection, are based on the Kullback–Leibler and Cook’s distances. Some simulation experiments are performed to compare all considered methods. Detection and error rates are used as comparison criteria. Numerical results provide evidence in favor of the KL distance.     

Methodological proposal for occupational health and safety actions in research laboratories with nanotechnologies activities

Nanotechnologies is a multidisciplinary set of techniques to manipulate matter on nanoscale level, more precisely particles below 100 nm whose characteristic due to small size is essentially different from those found in macro form materials. Regarding to these new properties of the materials there are knowledge gaps about the effects of these particles on human organism and the environment. Although it still being considered emerging technology it is growing increasingly fast as well as the number of products using nanotechnologies in some production level and so the number of researchers involved with the subject. Given this scenario and based on literature related, a comprehensive methodology for health and safety at work for researching laboratories with activities in nanotechnologies was developed, based on ILO structure guidelines for safety and health at work system on which a number of nanospecific recommendations were added to. The work intends to offer food for thought on controlling risks associated to nanotechnologies.     

Is there enough information to calculate the financial benefits of ergonomics projects?

Many authors studied work situations and, mainly, ergonomics projects concerning the financial benefit point of view. At the same time seems to be little information available concerning these financial benefits in manufacturing companies' processes. The aim of this article is to identify if there enough information available within a company to quantify the financial benefits of an ergonomic project. The study was applied on two manufacturing companies, one in Brazil and other in Portugal. A literature review based checklist and a manager interview was applied on each company in order to identify if the information was available and how were been used. The two companies have revealed a good quantity of available information regarding ergonomics benefit calculation. The interviews showed that managers are not aware of the financial savings possibility with investments in ergonomics projects.