Power Law Selection Model for Repairable Systems

A repairable system, under minimal repair, is usually modeled according to a Non-Homogeneous Poisson Process (NHPP) assuming a Power Law intensity function. A traditional approach considers iid NHPPs in order to conduct a statistical analysis based on a sample of systems. However, systems might be heterogeneous due to unmeasured variables such as age, suppliers, and so on. In order to verify this assumption a frequentist approach is proposed in this article. Some possible model scenarios considering different systems heterogeneity are compared using likelihood ratio tests and information criteria. Real data sets illustrate the proposed methodology.     

So Close,So Far. The Cultural Distance of Foreigners in Italy

Social Indicators Research - The presence of foreigners in a host country is a contentious issue: opponents claim, among other things, that the cultural distance between them and natives is too...     

The municipal solid waste and the quality of life of collectors of recyclable materials in Juiz de Fora, Minas Gerais

The generation growing and diversified of Municipal Solid Waste is configured as an environmental problem, economic and social deterioration, especially, by application of inappropriate management of them. Faced with this urban context, the research in development presents as specific objective assessment of the quality of life of the gatherers of recyclable materials were active in the city of Juiz de Fora, in the brazilian state of Minas Gerais. In addition, the objective is, still, the recognition of the activity of sorting performed by "scavengers" in order to maximize the reduction, reuse and recycling energy and material waste daily. The proposed methodology is based on the application of the questionnaire Word Health Organization Quality of Life (WHOQOL-100), prepared by the World Health Organization, in order to value the quality of life of the gatherers of recyclable materials, involved, even in educational workshops in order to discuss and organize strategies of health care and scouting to the basement to public policies.     

Radiological emergency response for community agencies with cognitive task analysis, risk analysis, and decision support framework

Radiological nuclear emergency responders must be able to coordinate evacuation and relief efforts following the release of radioactive material into populated areas. In order to respond quickly and effectively to a nuclear emergency, high-level coordination is needed between a number of large, independent organizations, including police, military, hazmat, and transportation authorities. Given the complexity, scale, time-pressure, and potential negative consequences inherent in radiological emergency responses, tracking and communicating information that will assist decision makers during a crisis is crucial. The emergency response team at the Angra dos Reis nuclear power facility, located outside of Rio de Janeiro, Brazil, presently conducts emergency response simulations once every two years to prepare organizational leaders for real-life emergency situations. However, current exercises are conducted without the aid of electronic or software tools, resulting in possible cognitive overload and delays in decision-making. This paper describes the development of a decision support system employing systems methodologies, including cognitive task analysis and human-machine interface design. The decision support system can aid the coordination team by automating cognitive functions and improving information sharing. A prototype of the design will be evaluated by plant officials in Brazil and incorporated to a future trial run of a response simulation.     

Can't Buy My Love: A Typology of Female Sex Workers' Commercial Relationships in the Mexico–U.S. Border Region

Female sex workers (FSWs) experience elevated risk for HIV and sexually transmitted infections (STIs) through unprotected sex with male clients, yet the complexity of these commercial relationships remains understudied. From 2010 to 2011, we explored FSWs' conceptualizations of various client types and related risk behavior patterns using semistructured interviews with 46 FSWs in Tijuana and Ciudad Juarez, Mexico, where FSWs' HIV/STI prevalence is increasing. Our grounded theory analysis identified four types of commercial relationships: nonregular clients, regular clients and friends, clients who “fell in love” with FSWs, and long-term financial providers who often originated from the United States. As commercial relationships developed, clients' social and emotional connections to FSWs increased, rendering condom negotiation and maintaining professional boundaries more difficult. Drug abuse and poverty also influenced behaviors, particularly in Ciudad Juárez, where lucrative U.S. clients were increasingly scarce. While struggling to cultivate dependable relationships in a setting marked by historical sex tourism from a wealthier country, some FSWs ceased negotiating condom use. We discuss the need for HIV/STI research and prevention interventions to recognize the complexity within FSWs' commercial relationships and how behaviors (e.g., condom use) evolve as relationships develop through processes that are influenced by local sociopolitical contexts and binational income inequality.     

Living in mobility: trajectories of Brazilians in Belgium and the UK

Within the social sciences, migration has traditionally been conceived of as a unidirectional, purposeful and intentional process from one state of fixity (in the place of origin) to another (in the destination). By mapping the trajectories of Brazilians who currently reside in Belgium or the UK, this article draws attention to a group of people whose mobile practices do not fit this definition. On the contrary, their experiences are marked by an ongoing mobility that consists of a multiplicity of potential routes, which are often unstable and which may be accompanied by changes in status. These Brazilians tend to ‘live in mobility’ in order to improve the quality of life at home. As such, leaving home becomes a strategy of staying home, which challenges what is usually evoked by the concept of ‘migration’, whereby ‘building up a new life elsewhere’ and ‘integration’ are seen as key. Whereas our respondents themselves have a more circular or mobile perspective, the receiving society discursively frames migration as one-way, and thus as a ‘threat’ that calls for social integration, control and the maintenance of national identity.     

Effects of Pilates method in physical fitness on older adults. A systematic review

Pilates method is employed for physical and mental conditioning. Elderly people could be benefited from a patterned and regulated conditioning work based on Pilates method. We performed a systematic review to assess the evidence on the effects of Pilates method in physical fitness on older adults. Our search included the following databases: MEDLINE-PubMed, Scopus and CINAHL Plus with Full Text via EBSCO and SPORTDiscus databases (up to April 2014). A summary of the results was performed using a best evidence synthesis and was reported according to the systematic review method proposed by Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodology quality of selected studies. Seventeen experimental studies were included in this review. Fourteen were randomized controlled trials (RCT) and three clinical controlled trials (CCT). Quality scores according to PEDro indicate low quality of the included studies (range 1–6, mean 3.8?±?1.2). The most studied components related to physical fitness were neuromotor fitness (n?=?11), muscle strength (n?=?8), cardiorespiratory endurance (n?=?4), body composition (n?=?4) and flexibility (n?=?4). Results indicate that Pilates method seems to present positive effects in neuromotor fitness, especially in static and dynamic balance. Related to the other components of physical fitness (cardiorespiratory endurance, muscle strength, body composition and flexibility), contradictory results were observed. The Pilates method indicates to be an appropriate exercise modality in order to improve balance on older adults. Nevertheless, more intervention research is needed to build a solid knowledge base about the health benefits of Pilates method on older people, especially regarding the other components of physical fitness.     

A weighted bootstrap approximation for comparing the error distributions in nonparametric regression

Several procedures have been proposed for testing the equality of error distributions in two or more nonparametric regression models. Here we deal with methods based on comparing estimators of the cumulative distribution function (CDF) of the errors in each population to an estimator of the common CDF under the null hypothesis. The null distribution of the associated test statistics has been approximated by means of a smooth bootstrap (SB) estimator. This paper proposes to approximate their null distribution through a weighted bootstrap. It is shown that it produces a consistent estimator. The finite sample performance of this approximation is assessed by means of a simulation study, where it is also compared to the SB. This study reveals that, from a computational point of view, the proposed approximation is more efficient than the one provided by the SB.     

An optimization approach applied to the optimal stratification problem

A new optimization algorithm is presented to solve the stratification problem. Assuming the number L of strata and the total sample size n are fixed, we obtain strata boundaries by using an objective function associated with the variance. In this problem, strata boundaries must be determined so that the elements in each stratum are more homogeneous among themselves. To produce more homogeneous strata, this paper proposes a new algorithm that uses the Greedy Randomized Adaptive Search Procedure (GRASP) methodology. Computational results are presented for a set of problems, with the application of the new algorithm and some algorithms from literature.