Escalada : una posibilidad educativa

Bibliografí

Introducing Type-2 Fuzzy Sets for Image Texture Modelling

In this paper, the texture property ”coarseness” is modeled by means of type-2 fuzzy sets, relating representative coarseness measures (our reference set) with the human perception of this texture property. The type-2 approach allows to face both the imprecision in the interpretation of the measure value and the uncertainty about the coarseness degree associated to a measure value. In our study, a wide variety of measures is analyzed, and assessments about coarseness perception are collected from pools. This information is used to obtain type-2 fuzzy sets where the secondary fuzzy sets are modelled by means of triangular membership functions fitted to the collected data

Fiabilidad de las cargas críticas de láminas delgadas estudiadas por ensamblaje de elementos planos triangulares en el M.E.F

El presente trabajo tiene por objeto poner de relieve el alto grado de confianza que podemos depositar en el valor de las cargas críticas calculdas en láminas, asismiladas por ensamblaje de elementos planos (método de E.F. ) triangulares tipo placa, sometidas a cargas gravitatorias uniformemente distriuidas.Peer Reviewe

Fiabilidad de las cargas críticas de láminas delgadas estudiadas por ensamblaje de elementos planos triangulares en el M.E.F

El presente trabajo tiene por objeto poner de relieve el alto grado de confianza que podemos depositar en el valor de las cargas críticas calculdas en láminas, asismiladas por ensamblaje de elementos planos (método de E.F. ) triangulares tipo placa, sometidas a cargas gravitatorias uniformemente distriuidas.Peer Reviewe

Daytime tropospheric loss of hexanal and <I>trans</I>-2-hexenal: OH kinetics and UV photolysis

International audienceThe ultraviolet (?=250?370 nm) photolysis and the OH-initiated oxidation of hexanal and trans-2-hexenal, which are relevant atmospheric processes, have been investigated at room temperature and as a function of temperature (T=263?353 K), respectively. This kinetic study as a function of temperature is reported here for the first time. Absolute absorption cross sections (??) were obtained using a recently built system operating in the UV region. The obtained ?? allowed the estimation of the photolysis rates (J) across the troposphere. Kinetic measurements of the gas-phase reaction of hydroxyl radicals (OH) with hexanal and trans-2-hexenal were performed by using the laser pulsed photolysis/laser-induced fluorescence technique. Rate coefficients kOH for both aldehydes were determined at temperatures between 263 and 353 K at 50 Torr in helium or argon bath gases. The temperature dependence of kOH for both aldehydes was found to be slightly negative. The tropospheric lifetime of hexanal and trans-2-hexenal due to the chemical removal by OH radicals has been estimated across the troposphere. The loss rate due to the OH chemical removal was compared with the estimated photolysis rates. Our results show that OH-reaction is the main loss process for these aldehydes in the troposphere, although photolysis is not negligible for hexanal