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Results for criterions: Parution: n° 195, Fall 2011 Modify search criterions 3 matches Title Efficient construction of the lattice of frequent closed patterns and simultaneous extraction of generic bases of rules Author MEPHU NGUIFO Engelbert, HAMROUNI Tarek, BEN YAHIA Sadok Keywords Closed pattern, Formal concept analysis, Lattice, Minimal generator, Rule Topic None Abstract In the last few years, the amount of collected data, in various computer science applications, has grown considerably. These large volumes of data need to be analyzed in order to extract useful hidden knowledge. This work focuses on association rule extraction. This technique is one of the most popular in data mining. Nevertheless, the number of extracted association rules is often very high, and many of them are redundant. In this paper, we propose a new algorithm, called PRINCE. Its main feature is the construction of a partially ordered structure for extracting subsets of association rules, called generic bases. Without loss of information these subsets form representation of the whole association rule set. To reduce the cost of such a construction, the partially ordered structure is built thanks to the minimal generators associated to fréquent closed patterns. The closed ones are simultaneously derived with generic bases thanks to a simple bottom up traversal of the obtained structure. The experimentations we carried out in benchmark and « worst case » contexts showed the efficiency of the proposed algorithm, compared to algorithms like CLOSE, A-CLOSE and TITANIC. Number 195, Fall 2011 Language   French Read the article Title The representation cone of an interval order Author DOIGNON Jean-Paul, PAUWELS Christophe Keywords Convex polyhedron, Interval order, Interval order representation Topic None Abstract A fixed, interval order is considered on a finite set of elements. When appropriately defined, its representations form a convex polyhedron. Our results describe the geometric structure of the polyhedron. The facets are in a one-to-one correspondence with the objects of one of four types: the minimal elements, the contractible elements as well as the noses and the hollows of the interval order (the latter notions are inferred from Doignon and Falmagne [1997]). The polyhedron has only one vertex, which is the minimal representation (in the meaning of Doignon [1988a]; new properties are established here). All representations thus form a convex cone. We characterize the extreme rays of this cone. The uniqueness of the vertex came as a surprise to us surprise because Balof, Doignon and Fiorini [2012] obtained, for the polyhedron formed by all representations of a semiorder, numerous examples with multiple vertices. Number 195, Fall 2011 Language  English Read the article Title The gladiators' game - A quality show Author BAZIN Damien, BALLET Jérome, VRANCEANU Radu Keywords Arbitration, Economics of sport, Gladiator, Quality of show Topic None Abstract Gladiator games constituted a major element under roman influence, which lingered on until the fourth century AD. The organization of these games was very expensive, and gladiators were to a large extent professionals, trained in gladiator schools. The overall costs were covered by fees paid by the Roman Magistrates who organized these shows. In order to attract them, the quality of the show was essential. From this point of view, the key person in the process of preparation of the show was the President who was granted the right to decide over life and death of the defeated gladiator. The judge’s strategy had a major impact on the quality of the show. Number 195, Fall 2011 Language   French Read the article Users rights : The entire journal is licensed under a Creative Commons license