In the framework of bilateral assignment games, we study the set of matrices associated with assignment markets with the same core. We state conditions on matrix entries that ensure that the related assignment games have the same core.We prove that the set of matrices leading to the same core form a join-semilattice with a finite number of minimal elements and a unique maximum. We provide a characterization of the minimal elements. A sufficient condition under which the join-semilattice reduces to a lattice is also given.Keywords: assignment game, core, semilattice JEL: C71Resumen: En el contexto de los juegos de asignación bilaterales, estudiamos el conjunto de matrices asociadas a mercados de asignación con el mismo núcleo. Se proporcionan condiciones sobre las entradas de la matriz que aseguran que los juegos de asignación asociados tienen el mismo núcleo. Se prueba que este conjunto de matrices que dan lugar al mismo núcleo forman un semirretículo con un número finito de elementos minimales y unúnico máximo. Se da una caracterización de estos elementos minimales. También se proporciona una condición suficiente para obtener un retículo.

The assignment game [6] is a model for a two-sided market where there is an exchange of indivisible goods for money and buyers or sellers demand or supply exactly one unit of the good. We give a procedure to compute the nucleolus of any assignment game, based on the distribution of equal amounts to the agents, until the game is reduced to less agents.

Els nous plans d'estudis en les universitats espanyoles s'estructuren a partir de l'especificació de les competències associades al títol. Freqüentment s'estableix com una competència a assolir la comunicació efectiva a un públic especialitzat o no especialitzat de determinats continguts. En aquest article s'estudien les infografies com a estratègia d'aprenentatge per analitzar i aprofundir en les competències comunicatives dels estudiants, aplicades a l'ensenyament de les finances i les assegurances.

The implementation of the ECTS system (European Credit Transfer System) has been initially tested in the course "Fundamentals of Chemistry" with the aim of improving the teaching methodology and student assessments used in previous years. With this aim in mind, the number of lectures has been reduced and students' participation encouraged using both individual tasks (problem solving and class discussions) and group work (cooperative actions). These changes have increased the workload for both student and faculty, but the achieved results indicate learning and attitudinal gains as the number of students approved increased in a 10% respect to previous years.

The aim of this work is to demonstrate the importance of the fact that from the beginning of the course students and teachers identify what is the initial knowledge level and the level that students must reach at the end of the course. This is important for the student because it will demonstrate the importance of the continuous assessment (Bologne methodology) and in the other hand, for the teachers to know the initial level of their students. It can give influence to detect deficiencies and solve them to a well ending course. This helps a lot to students with an initial lack of knowledge of the subject. This study carries out specifically in the Chemistry subject in the degree