Lacunarity, predictability and predictive instability of the daily pluviometric regime in the Iberian Peninsula

International audienceThe complexity of the daily pluviometric regime of the Iberian Peninsula is analysed from the point of view of its lacunarity, predictability and predictive instability. The database consists of daily pluviometric records obtained from 43 rain gauges in Spain and Portugal for the period 1950?1990. Five different series are generated for every rain gauge. The first series is constituted by the consecutive daily amounts. The other four consist of dry spell lengths with respect to daily amount thresholds of 0.1, 1.0, 5.0 and 10.0 mm/day. A dry spell length is defined as the number of consecutive days with rainfall amounts below one of these thresholds. The empirical lacunarity for every rain gauge is well reproduced by two power laws, the exponents varying notably from one gauge to another. The spatial distribution of the lacunarity is characterised by a north to south or southeast gradient, thus suggesting that this parameter can be a useful tool to distinguish between different pluviometric regimes. The predictability of the five series is quantified by means of the rescaled analysis and the interpretation of the Hurst exponent. Its patterns reveal that most part of the Iberian Peninsula shows signs of persistence for the daily rainfall and the dry spell series, although persistence is only clearly manifested in some small domains. The instability of possible predictive algorithms is analysed through the Lyapunov exponents. They are only computed for the series of daily amounts and for dry lengths respect to the threshold level of 0.1 mm/day due to the short number of dry spells for larger threshold levels. The series of daily amounts depict the highest instability along the Mediterranean coast. The series of dry spells show an increasing instability from NE to SW Spain, with a relevant nucleus of high Lyapunov values in the south-western Atlantic coast. As a summary, lacunarity and Hurst and Lyapunov exponents depict a relevant spatial variation, which is in agreement with well known patterns of the pluviometric regime, such as annual amount spatial distribution and return periods of dry spells

Predictability of the monthly North Atlantic Oscillation index based on fractal analyses and dynamic system theory

The predictability of the monthly North Atlantic Oscillation, NAO, index is analysed from the point of view of different fractal concepts and dynamic system theory such as lacunarity, rescaled analysis (Hurst exponent) and reconstruction theorem (embedding and correlation dimensions, Kolmogorov entropy and Lyapunov exponents). The main results point out evident signs of randomness and the necessity of stochastic models to represent time evolution of the NAO index. The results also show that the monthly NAO index behaves as a white-noise Gaussian process. The high minimum number of nonlinear equations needed to describe the physical process governing the NAO index fluctuations is evidence of its complexity. A notable predictive instability is indicated by the positive Lyapunov exponents. Besides corroborating the complex time behaviour of the NAO index, present results suggest that random Cantor sets would be an interesting tool to model lacunarity and time evolution of the NAO index

Semantic Object Parsing with Graph LSTM

By taking the semantic object parsing task as an exemplar application scenario, we propose the Graph Long Short-Term Memory (Graph LSTM) network, which is the generalization of LSTM from sequential data or multi-dimensional data to general graph-structured data. Particularly, instead of evenly and fixedly dividing an image to pixels or patches in existing multi-dimensional LSTM structures (e.g., Row, Grid and Diagonal LSTMs), we take each arbitrary-shaped superpixel as a semantically consistent node, and adaptively construct an undirected graph for each image, where the spatial relations of the superpixels are naturally used as edges. Constructed on such an adaptive graph topology, the Graph LSTM is more naturally aligned with the visual patterns in the image (e.g., object boundaries or appearance similarities) and provides a more economical information propagation route. Furthermore, for each optimization step over Graph LSTM, we propose to use a confidence-driven scheme to update the hidden and memory states of nodes progressively till all nodes are updated. In addition, for each node, the forgets gates are adaptively learned to capture different degrees of semantic correlation with neighboring nodes. Comprehensive evaluations on four diverse semantic object parsing datasets well demonstrate the significant superiority of our Graph LSTM over other state-of-the-art solutions.Comment: 18 page

Unexpected differences between thermal and photoinitiated cationic curing of a diglycidyl ether of bisphenol A modified with a multiarm star poly(styrene)-b-poly(ε-caprolactone) polymer

The effect of adding a multiarm star poly(styrene)-b-poly(ε-caprolactone) polymer on the cationic thermal and photoinitiated curing of diglycidyl ether of bisphenol A was studied. This star-polymer decelerated the thermal curing of diglycidyl ether of bisphenol A and modified the final structure of the epoxy matrix. The photocuring was influenced significantly by the addition of the multiarm star. When the proportion of this modifier added was 5%, much more time was necessary for complete photocuring (160 min at 40ºC). In the presence of 10% of modifier, the degree of photocuring reached was very low (0.196 at 120°C). A subsequent thermal post-curing was necessary to cure completely the system. During photocuring in presence of poly(styrene)-b-poly(ε-caprolactone), the formation of dormant species, which are reactivated when the temperature increases, takes places. The kinetics of the thermal curing and the photocuring was analyzed using an isoconversional method due to the complexity of the reactive process. Applying this method, it has been confirmed the dependence of activation energy on the degree of conversion. The fracture morphology analyzed by scanning electron microscopy exhibited a second phase originated during photocuring by the presence of the modifier

Digital audio effects

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Changes in the density profile due to the m=2 tearing mode in asdex

Resistive MHO tearing modes can develop magnetic islands near the rational magnetic surfaces, where q=m/ n

Evaluación de la calidad del seguimiento de las tutorías y los resultados de aprendizaje en las estancias clínicas en el grado de Fisioterapia de la UIC

Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Introducció: Les estades clíniques (EC) en el grau de Fisioteràpia de la UIC sumen 40 ECTS distribuïts entre tercer i quart curs en períodes de 5 ECTS d’acord amb el RD 17/07/2011 que regula les pràctiques curriculars, assignant un tutor a l’alumne en rati de 1/1. El tutor és l’encarregat del seguiment y desenvolupament de les EC. Objectiu: Valorar la percepció dels alumnes sobre la qualitat de les tutories en relació a la seva opinió vers els resultats d’aprenentatge en les EC. Metodologia: Al finalitzar cada un dels períodes de les EC, de forma aleatòria es facilita un qüestionari específic sobre estades clíniques en fisioteràpia (CECF) elaborat i validat per Gallego l’any 1999, compost per 7 dimensions 2 de les quals estan conformades per preguntes sobre la percepció que els alumnes tenen del seguiment dels tutors i la seva opinió sobre els resultats d’aprenentatge obtinguts amb rangs de 9 a 36 y de 32 a 128 respectivament. Resultats: La mostra fou de 70 alumnes (40% homes) amb una mitjana d’edat de 23.24(3.47). La puntuació mitjana en les dimensions de tutories i resultats fou de 25.51(8.19) i 84.57(11.15) respectivament. Entre aquestes s’observa una correlació significativa però dèbil (r=0,354). En relació a les associacions entre les preguntes que conformen cada una de les dimensions, es destaca la que està més relacionada, segons manifesten els alumnes, amb els resultats obtinguts, és si el sistema de tutories cobreix les seves necessitats de suport i ajuda, seguida de la que també pregunta el grau d’acord amb que les tutories ajudin a resoldre dubtes. Així mateix, les preguntes de resultats amb les que aquestes estan més relacionades fan referència a les habilitats adquirides al final de les EC, i en concret en saber aplicar el mètode d’intervenció en fisioteràpia en diferents aspectes com la valoració o el tractament. Conclusions: La percepció que tenen els alumnes del seguiment dels tutors d’estades clíniques influeix sobre la opinió que els mateixos tenen dels resultats d’aprenentatge específics de la pràctica clínica en fisioteràpia obtinguts