An alternative method for global and partial comparison of two diagnostic systems based on ROC curves

In this paper, an alternative method for the comparison of two diagnostic systems based on receiver operating characteristic (ROC) curves is presented. ROC curve analysis is often used as a statistical tool for the evaluation of diagnostic systems. However, in general, the comparison of ROC curves is not straightforward, in particular, when they cross each other. A similar difficulty is also observed in the multi-objective optimization field where sets of solutions defining fronts must be compared with a multi-dimensional space. Thus, the proposed methodology is based on a procedure used to compare the performance of distinct multi-objective optimization algorithms. In general, methods based on the area under the ROC curves are not sensitive to the existence of crossing points between the curves. The new approach can deal with this situation and also allows the comparison of partial portions of ROC curves according to particular values of sensitivity and specificity of practical interest. Simulations results are presented. For illustration purposes, considering real data from newborns with very low birthweight, the new method was applied in order to discriminate the better index for evaluating the risk of death.     

Paying Enough but not Paying too Much When There is no Third-Party Endorsement: Executive Compensation and Individual Donations for Nonprofit Organizations

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - We examine whether third-party endorsement and institutional trust can mitigate the potential negative effects of higher...     

Evaluation of thermal overload in boiler operators

The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload.     

Assessment of physical workload in boiler operations

The use of boiler wood-fired is fairly common equipment utilized in steam generation for energy production in small industries. The boiler activities are considered dangerous and heavy, mainly due to risks of explosions and the lack of mechanization of the process. This study assessed the burden of physical labor that operators of boilers are subjected during the workday. Assessment of these conditions was carried out through quantitative and qualitative measurements. A heart rate monitor, a wet-bulb globe thermometer (WBGT), a tape-measure and a digital infrared camera were the instruments used to collect the quantitative data. The Nordic Questionnaire and the Painful Areas Diagram were used to relate the health problems of the boiler operator with activity. With study, was concluded that the boiler activity may cause pains in the body of intensity different, muscle fatigue and diseases due to excessive weight and the exposure to heat. The research contributed to improve the boiler operator's workplace and working conditions.     

Ergonomic assessment of porridge roaming sale system

This paper makes suggestions for the realization of an ergonomic intervention, guided by the method of Moraes and Mont'Alv?o (2009), in the system of street vending of porridge, to improve the working conditions of this sales segment. Specifics are given about this practice and its problems, from ergonomic analysis comes to suggestions for improvements to be applied to a new system.     

A precarious hegemony: neo-liberalism,social struggles,and the end of Lulismo in Brazil

ABSTRACT

Analysis of Brazil’s political and economic crisis tends to emphasize the economic ‘errors’ that President Dilma Rousseff’s Workers’ Party (PT) government inherited from her predecessor Luíz Inácio Lula da Silva. It is clear, however, that political regulation is too narrow a focus to understand the current crisis. Such an explanation is unable to reveal the changes in class structure that took place during the Lula era as well as the effects of the international economic crisis. This article identifies the limits of the Brazilian development model and the main features of Lula’s mode of regulation; analyses the conflicts produced by the neo-liberal regime of accumulation and the Lulista mode of regulation, emphasizing the role of precarious work in the current historical cycle of strikes and popular struggles in Brazil; and, finally, interprets the palace coup promoted by the social forces behind the impeachment of President Rousseff.     

The heteroscedastic odd log-logistic generalized gamma regression model for censored data

We propose a four-parameter extended generalized gamma model, which includes as special cases some important distributions and it is very useful for modeling lifetime data. A advantage is that it can represent the error distribution for a new heteroscedastic log-odd log-logistic generalized gamma regression model. The proposed heteroscedastic regression model can be used more effectively in the analysis of survival data since it includes as special models several widely-known regression models. Further, for different parameter settings, sample sizes and censoring percentages, various simulations are performed. Overall, the new regression model is very useful to the analysis of real data.