Ergonomics in designing process: dialogue between designers, executors and users in the maintenance activity of radars in an oil refinery

This paper aims to discuss the role of ergonomics in design process using the dialogue developed by designers, implementers and users in an oil refinery. It was possible to identify the need of minimizing the postural constraints, risk of accidents, mechanical shocks and to enlarge safety perception in the access and permanency of the users at the workspace. It has been determined and validated by workers and managers to implement different deadlines depending on programming, viability and execution time for the improvements proposed. In a long-term: it was proposed the substitution of the ladders with time planning according to the maintenance program of the tanks; in a short-time: it was suggested the expansion of the existing platforms, implementation of a walkway connection provided with guardrails between the upper access of the side ladder and the repositioning of radar set and aerial aiming at the usage by workers at the workstation of the new platform. It was also elaborated eight typologies of intervention, according to the request, type of tank, material stored, and its setting place. The design process arises from ergonomics workplace analysis that presents concepts for solutions which was a mediator tool to be settled between users and implementers.     

Efficiency of personal protective equipment used in agriculture

Despite the practical importance of Personal Protective Equipment (PPE), both in production and in consumption, it is observed a main problem regarding the quality of many PPE?s used in Brazil. This study found a gap between the state of the art and the state of prevailing practices in the design of PPE?s, which main consequences affect the health of workers who use PPE in agriculture activities. The results of this study identified legal constraints of this occurrence, involving the validation of PPE designed for isolate agents, without the analysis of relevant activities and without prototypes experiments in more frequent use situation.     

The footwear factory's assembly sector: opposing organizational structure and quality from the ergonomic work analysis

Data from 2006 indicated that Brazilian footwear leather industry was composed of approximately 9,488 formally registered establishments, considering the leather industry, footwear and leather goods. It was responsible for 211,582 people employed. However, in spite of having many employees, this kind of organization found several problems when analyzed from the ergonomics view. With this premise, then, in order to identify bottlenecks and other engineering problems that could cause discomfort and motivation lack among workers, leading directly to the loss of the product quality, the assembly sector of women's shoes factory was characterized.     

A longitudinal perspective on the differentiated valuation of formal education in Brazil in recent decades

The central theme of this article is the relationship between formal education and earnings from a longitudinal perspective, taking into account indicators of social status. Variations in the respective trajectories, in different age cohorts, and in the comparison among different periods are discussed. The empirical material used is based on the microdata files of official statistics. The main techniques put into practice are those that are most focused on measuring the degree of interdependence among variables and those used for means comparison. Our general hypothesis is that the effects of schooling cannot be grasped in terms of education itself but instead in terms of its relationship to status in the social and power structures. One of this paper's principal observations is that of the general declining trend in the economic value of formal education, which varies depending on the level of education and social status. This devaluation is systematic and spans the entire studied universe; however, it focuses much more closely on those of lower social status, particularly for the groups with schooling that is either higher or lower than average.     

GMC/GEL estimation of stochastic volatility models

In this article we discuss the estimation of stochastic volatility (SV) using generalized empirical likelihood/minimum contrast methods based on moment conditionsmodels. We show via Monte Carlo simulations that the proposed methods have superior or equivalent performance to the other alternative methods, and, additionally, they offer robustness properties in the presence of heavy-tailed distributions and outliers.     

The inverse weighted Lindley distribution: Properties,estimation and an application on a failure time data

In this paper a new distribution is proposed. This new model provides more flexibility to modeling data with upside-down bathtub hazard rate function. A significant account of mathematical properties of the new distribution is presented. The maximum likelihood estimators for the parameters in the presence of complete and censored data are presented. Two corrective approaches are considered to derive modified estimators that are bias-free to second order. A numerical simulation is carried out to examine the efficiency of the bias correction. Finally, an application using a real data set is presented in order to illustrate our proposed distribution.     

A strange tale

We are going through such challenging times that dealing with reality is sometimes easier through fiction. Therefore, we tell the tale of a faraway land where poor women — mostly black — who make a living as domestic servants are particularly impacted by the COVID‐19 pandemic. Their abject bodies are part of a form of necropolitics that separates those who must live from those who can die. Their bodies do not matter, as they are perceived as mere working tools. And what sounds like a strange tale is the true reality of millions of women during the pandemic, in a land that is not so far away as it seems.     

Restricted alternatives tests in a bivariate exponential model with covariates

This paper is about the analysis of paired survival data using the exponential bivariate model of Sarkar for the underlying survival times, (X,Y), subject to censoring. Under this parametric model we test parameters in the presence of covariates. We consider first, tests of hypotheses of independence and equality of survival marginals, and second, test of hypotheses of covariate effects and survival superiority of one marginal over the other are considered. For this last question we applied a statistical test based on the Union-intersection principle.     

Testing Covariance Stationarity

In this paper, we show that the widely used stationarity tests such as the Kwiatkowski Phillips, Schmidt, and Shin (KPSS) test have power close to size in the presence of time-varying unconditional variance. We propose a new test as a complement of the existing tests. Monte Carlo experiments show that the proposed test possesses the following characteristics: (i) in the presence of unit root or a structural change in the mean, the proposed test is as powerful as the KPSS and other tests; (ii) in the presence of a changing variance, the traditional tests perform badly whereas the proposed test has high power comparing to the existing tests; (iii) the proposed test has the same size as traditional stationarity tests under the null hypothesis of stationarity. An application to daily observations of return on U.S. Dollar/Euro exchange rate reveals the existence of instability in the unconditional variance when the entire sample is considered, but stability is found in subsamples.