Sergio Luis Pérez-Pérez

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The traveling repairman problem is a scheduling problem in which a repairman is supposed to visit some customers at their locations to perform some jobs. Each customer has a time window during which the repairman is allowed to arrive to perform the jobs. The goal is to maximize the number of visited locations. In this work we deal with a special case in(More)
A graph is said to be planar if it can be drawn on the plane with vertices as different points and edges as continuous curves that only intersect its vertices. An embedding of a graph is said to be primitive if its edges are primitive segments. A recent conjecture is that all planar graphs with n vertices have a primitive embedding in a square grid of side(More)
Palabras clave. Selección aleatoria de árboles generadores, paseos aleatorios sobre gráficas, matrices de transición en cadenas de Markov, distribuciones de probabilidad en vecindades de vértices. Abstract. Random selection of spanning trees on graphs has been treated extensively in technical literature. Popular randomized algorithms have time complexity(More)
The word problem and indeed the enu- meration problem in Coxeter groups are intractable in most cases. A direct way to solve the enumeration problem is by listing the canonical representatives of the equivalence classes, but this entails to solve the word problem for certain pairs of words in the group. We describe two methods to solve these problems and we(More)
OBJECTIVE Previous epidemiologic studies have shown that around 5% of the population will suffer a tonic clonic seizure during their life. The aim of this study is to know how many and which of these people will suffer a second seizure and become epileptic. PATIENTS AND METHODS 175 patients seen in the emergency department of the Vall d Hebron Hospital(More)
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