Fuzzy set Theory and Quantum Chemistry

Es discuteixen breument algunes consideracions sobre l'aplicació de la Teoria dels Conjunts difusos a la Química quàntica. Es demostra aqui que molts conceptes químics associats a la teoria són adequats per ésser connectats amb l'estructura dels Conjunts difusos. També s'explica com algunes descripcions teoriques dels observables quàntics es potencien tractant-les amb les eines associades als esmentats Conjunts difusos. La funció densitat es pren com a exemple de l'ús de distribucions de possibilitat al mateix temps que les distribucions de probabilitat quàntiques

The Syntactic Information in the 'Diccionario Crítico Etimológico Castellano e Hispánico' by J. Corominas and J.A. Pascual as Expressed in the Database 'Syntax.Dbf'

L'objectiu d'aquest article és presentar l'estructura de la base de dades relacional que inclou tota la informació sintictica continguda en el Diccionario Critico Etimológico Castellano e Hispánico de J. Corominas i J. A. Pascual. Tot i que aquest diccionari conté un ampli ventall d'informacions històriques de cadascun dels temes, aquestes no es mostren de forma estructurada, per la qual cosa ha estat necessari estudiar i classificar tots aquells elements relacionats amb aspectes sintàctics. És a partir d'aquest estudi previ que s'han elaborat els diferents camps de la base de dades, els quals s'agrupen en cinc blocs temàtics: informació lemàtica; gramatical; sintàctica; altres aspectes relacionats; i observacions o comentaris rellevants fets per l'investigador. Aquesta base de dades no només reprodueix els continguts del diccionari, sinó que inclou diferents camps interpretatius. Per aquesta raó, Syntax. dbf representa una eina de treball fonamental per a tots aquells investigadors interessats en la sintaxi diacrònica de l'espanyol

Predictive vegetation mapping in the Mediterranean context: Considerations and methodological issues

The need to map vegetation communities over large areas for nature conservation and to predict the impact of environmental change on vegetation distributions, has stimulated the development of techniques for predictive vegetation mapping. Predictive vegetation studies start with the development of a model relating vegetation units and mapped physical data, followed by the application of that model to a geographic database and over a wide range of spatial scales. This field is particularly important for identifying sites for rare and endangered species and locations of high biodiversity such as many areas of the Mediterranean Basin. The potential of the approach is illustrated with a mapping exercise in the alti-meditterranean zone of Lefka Ori in Crete. The study established the nature of the relationship between vegetation communities and physical data including altitude, slope and geomorphology. In this way the knowledge of community distribution was improved enabling a GIS-based model capable of predicting community distribution to be constructed. The paper describes the development of the spatial model and the methodological problems of predictive mapping for monitoring Mediterranean ecosystems. The paper concludes with a discussion of the role of predictive vegetation mapping and other spatial techniques, such as fuzzy mapping and geostatistics, for improving our understanding of the dynamics of Mediterranean ecosystems and for practical management in a region that is under increasing pressure from human impact.

A genetic algorithm for the design of a fuzzy controller for active queue management

Active queue management (AQM) policies are those policies of router queue management that allow for the detection of network congestion, the notification of such occurrences to the hosts on the network borders, and the adoption of a suitable control policy. This paper proposes the adoption of a fuzzy proportional integral (FPI) controller as an active queue manager for Internet routers. The analytical design of the proposed FPI controller is carried out in analogy with a proportional integral (PI) controller, which recently has been proposed for AQM. A genetic algorithm is proposed for tuning of the FPI controller parameters with respect to optimal disturbance rejection. In the paper the FPI controller design metodology is described and the results of the comparison with random early detection (RED), tail drop, and PI controller are presented.