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Niterói, Brazil

Craizer M.,Pontifical Catholic University of Rio de Janeiro | Teixeira R.C.,UFF
Discrete and Computational Geometry | Year: 2013

In this paper we consider convex planar polygons with parallel opposite sides. These polygons can be regarded as discretizations of closed convex planar curves by taking tangent lines at samples with pairwise parallel tangents. For such polygons, we define discrete versions of the area evolute, central symmetry set, equidistants, and area parallels and show that they behave quite similarly to their smooth counterparts. © 2013 Springer Science+Business Media New York. Source


Among the various oilseeds, the castor bean was identified by the National Program for Production and Use of Biodiesel, as the ideal one to promote social development in Brazil's northeast region. However the survey shows that the production of this raw material was not competitive for biodiesel production. The research is qualitative, descriptive and exploratory, and multi-case studies were used for their analysis. The instrument used for data collection was a semi-structured personal interview. Visits to production units were also conducted, which enabled data triangulation. Thus, this paper describes each driver and presents a picture of the competitiveness of both agricultural and industrial productions in this chain. The influence of each driver was evaluated using a Likert scale. The results present a clear view of the competitive segments in the analyzed agribusiness chain. Source


de Lima Cavaliere I.A.,Federal University of Fluminense | Costa S.G.,UFF
Physis | Year: 2011

This exploratory work examines the social isolation experienced by individuals with leprosy admitted to the former colony Tavares de Macedo, Itaboraí, where they were kept from the 1930s until the present day, to question notions of segregation and social discrimination present in this environment. So it analyzes sociabilities and social care networks established in the common life in this "ex-leper colony," usually as alternatives to the conditions offered by the public systems of social protection. The work is based on stories of some of the subjects, seen in their differences - at intersection of gender relations, classes, races/ethnicities, generations and also by religions and educational backgrouns. It adopts the oral history, so as to offer new qualitative interpretations of social and historical processes shown in these networks and sociability, not always visible as unique forms of social protection of life in groups. Source


The methods of multi-criteria decision aid are applied to problems of selection, ranking, classifying, and describing alternatives in the presence of multiple criteria, both quantitative and qualitative. This article tackles the problem of using the UTA and UTA-CR methods for determining the utility function of criteria used to evaluate candidates for the undergraduate program in metallurgical engineering in the Fluminense Federal University. After presenting the methods and outlining the problem, an analysis of the results shows that the utility functions of criteria obtained using UTA-CR are closer to decision-maker preferences than those obtained using UTA. It is also shown that, by using UTA-CR, it is not necessary to perform the post-optimization analysis that is required by the UTA method. In other words, implementation of a single linear program leads to results that are better than those obtained using UTA. Source


Craizer M.,Pontifical Catholic University of Rio de Janeiro | Teixeira R.C.,UFF
Discrete and Computational Geometry | Year: 2012

In this paper we discuss some affine properties of convex equal-area polygons, which are convex polygons such that all triangles formed by three consecutive vertices have the same area. Besides being able to approximate closed convex smooth curves almost uniformly with respect to affine length, convex equal-area polygons admit natural definitions of the usual affine differential geometry concepts, like affine normal and affine curvature. These definitions lead to discrete analogous to the six-vertex theorem and an affine isoperimetric inequality. One can also define discrete counterparts of the affine evolute, parallels and the affine distance symmetry set preserving many of the properties valid for smooth curves. © 2012 Springer Science+Business Media, LLC. Source

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