Sabir Ribas

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This work presents Integer Programming (IP) techniques to tackle the problem of the International Nurse Rostering Competition. Starting from a compact and monolithic formulation in which the current generation of solvers performs poorly, improved cut generation strategies and primal heuristics are proposed and evaluated. A large number of computational(More)
In this paper we discuss the problem of how to assess academic productivity based on publication outputs. We are interested in knowing how well a research group in an area of knowledge is doing relatively to a pre-selected set of reference groups, where each group is composed by academics or researchers. To assess academic productivity we adopt a new metric(More)
Static rankings of papers play a key role in the academic search setting. Many features are commonly used in the literature to produce such rankings, some examples are citation-based metrics, distinct applications of PageRank, among others. More recently, learning to rank techniques have been successfully applied to combine sets of features producing(More)
In this work we propose a metric to assess academic productivity based on publication outputs. We are interested in knowing how well a research group in an area of knowledge is doing relatively to a pre-selected set of reference groups, where each group is composed by academics or researchers. To assess academic productivity we propose a new metric, which(More)
The identification of reputable entities is an important task in business, education, and many other fields. On the other hand, as an arguably subjective, multi-faceted concept, quantifying reputation is challenging. In this paper, instead of relying on a single, precise definition of reputation, we propose to exploit the transference of reputation among(More)
To manage the problem of having a higher demand for resources than availability of funds, research funding agencies usually rank the major research groups in their area of knowledge. This ranking relies on a careful analysis of the research groups in terms of their size, number of PhDs graduated , research results and their impact, among other variables.(More)
The Vehicle Routing Problem with Time Windows is a particular case of the classical Vehicle Routing Problem in which the demands of each customer should be met within an established time window. Due to the combinatorial complexity of the problem its resolution by pure exact methods is, in many cases, computationally impractical. This fact motivates the(More)
We investigated the feeding habits of the teiid lizard Cnemidophorus littoralis in the markedly seasonal habitat of Restinga da Barra de Maricá (22 degrees 57'S, 43 degrees 50'W), Rio de Janeiro State, Brazil, to evaluate to what extent its diet is ontogenetically, sexually, and/or seasonally conservative. Lizard stomach contents were analyzed, identified,(More)
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