Fuzzy metrics and fuzzy logic for colour image filtering

El filtrado de imagen es una tarea fundamental para la mayoría de los sistemas de visión por computador cuando las imágenes se usan para análisis automático o, incluso, para inspección humana. De hecho, la presencia de ruido en una imagen puede ser un grave impedimento para las sucesivas tareas de procesamiento de imagen como, por ejemplo, la detección de bordes o el reconocimiento de patrones u objetos y, por lo tanto, el ruido debe ser reducido. En los últimos años el interés por utilizar imágenes en color se ha visto incrementado de forma significativa en una gran variedad de aplicaciones. Es por esto que el filtrado de imagen en color se ha convertido en un área de investigación interesante. Se ha observado ampliamente que las imágenes en color deben ser procesadas teniendo en cuenta la correlación existente entre los distintos canales de color de la imagen. En este sentido, la solución probablemente más conocida y estudiada es el enfoque vectorial. Las primeras soluciones de filtrado vectorial, como por ejemplo el filtro de mediana vectorial (VMF) o el filtro direccional vectorial (VDF), se basan en la teoría de la estadística robusta y, en consecuencia, son capaces de realizar un filtrado robusto. Desafortunadamente, estas técnicas no se adaptan a las características locales de la imagen, lo que implica que usualmente los bordes y detalles de las imágenes se emborronan y pierden calidad. A fin de solventar este problema, varios filtros vectoriales adaptativos se han propuesto recientemente. En la presente Tesis doctoral se han llevado a cabo dos tareas principales: (i) el estudio de la aplicabilidad de métricas difusas en tareas de procesamiento de imagen y (ii) el diseño de nuevos filtros para imagen en color que sacan provecho de las propiedades de las métricas difusas y la lógica difusa. Los resultados experimentales presentados en esta Tesis muestran que las métricas difusas y la lógica difusa son herramientas útiles para diseñar técnicas de filtrado,Morillas Gómez, S. (2007). Fuzzy metrics and fuzzy logic for colour image filtering [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1879Palanci

Kramers problem and energy diffusion

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2024, Tutor: Ivan LatellaThe thermally activated escape of a Brownian particle over a potential barrier can be treated by the Smoluchowski equation if the high friction limit is considered. If the friction is weak, however, a different approach must be taken which is based on the concept of energy diffusion. The associated Kramers problem is to determine the rate at which the particle escapes from the potential well defining the barrier. In this work, through theory and simulations, we quantify the escape time as the mean first-passage time taken by the particle to cross the barrier by considering the energy diffusion approac

Generation of tailored boundary layer meshes for nonequilibrium flows

The intention of the present work is to generate meshes tailored to the boundary layer to improve the flow predictions of wall-modeled large-eddy simulations (WM-LES). To this end, the local reconstruction-method was implemented to measure the boundary layer thickness using the computations of a constant-height grid as a baseline. The NASA Juncture Flow is used as benchmark. WMLES using Alya were conducted for an angle of attack of AoA = 5 0 and Reynolds number based on the crank chord Re c = 2.4 · 10 6 . The errors in the prediction of mean velocity profiles are characterized at two different locations over the aircraft: the upstream region of the fuselage, and the wing-body juncture close to the leading-edge. Better prediction of the flow close to the wall are observed with the tailored mesh with a equilibrium wall-function, especially at the upstream location where the equilibrium hypothesis holds

Life cycles or longer tenures? A performance and employment duration model for Spanish basketball coaches

This work has been partially funded by the Spanish Ministry of Education (project ECO2010-20483) and the Regional Government of Andalusia (project P11-SEJ-7988).This study analyses the effect of basketball coaches on performance and the question of life cycles on their tenures. From theoretical perspectives like coach-performance relationship, succession theories, life cycle theory,and based on a longitudinal analysis from 1997 to 2012 of a professional Spanish basketball league, we show that the objective established at the season’s start and coach quality positively influence team performance, that a mid-season coaching change negatively influences performance, and the existence of longer tenures coaches that improve team performance. The work is especially interested for sport managers, sport coaches in their decisions-taking, but it is useful to general management to understand the consequences of the tenures or dismissals of their key managers on results.Spanish Ministry of Education ECO2010-20483Regional Government of Andalusia P11-SEJ-798

Recovering performance in the short term after coach succession in Spanish basketball organisations

This work has been partially funded by the Spanish Ministry of Education (project ECO2013-47009-P) and the Regional Government of Andalusia (project P11-SEJ-7988). The authors want to thank the members of the research group, “Innovation, Sustainability and Business Development” (SEJ-481).Research papers on succession processes in sports organisations have usually shown contradictory results. Several factors can explain the different effects on performance after changes, so the purpose of this paper is to obtain a better understanding of coach changes and their impacts on short-term performance. For this purpose, we use ordinary least squares (with Stata) to analyse panel data from a longitudinal sample of 15 years (from the 1997–1998 season to the 2011–2012 season) of Spanish professional basketball organisations, examining all changes in head coaches that occurred during the teams’ competitive seasons using the variables of coach experience or human capital changes within the organisation after the change of coach to determine the repercussions of these changes on performance. The results, with p < .05, support two hypotheses: H2, the possibility of short-term improved performance in organisations after a coach change; and H3, if a coach change is accompanied by more profound changes in human capital (players) the result is worse performance. These results are not contradictory because they indicate that it is possible to recover performance in the short term, but if managers make too many changes at the same time, the team cannot coordinate itself to recover its performance. For organisations, this observation is important because organisations can change key leaders when performance is low but must consider that a large number of simultaneous changes are overly risky because this increases instability and disruption.Spanish Ministry of Education (project ECO2013-47009-P)Regional Government of Andalusia (project P11-SEJ-7988

High performance of professional basketball players and the settings to measure their regularity: evidence from the Spanish ACB League

Available at: <http://siba-ese.unisalento.it/index.php/ejasa/article/view/19295/17877In this paper, we analyse the relationship between performance and regularity to avoid the problem to the use of averages in sports statistics given their sensitivity to extreme data. The aim of this work is to establish which statistics discriminate between the high and low performance and regularity of basketball players using a performance-regularity index. The sample is composed of players from the Spanish professional basketball league, ACB League, from 2014-2015. We divided the sample into players with low, medium and high performance and regularity through a k-means method and a discriminant analysis associating high numbers of rebounds, assists and steals with high performance and regularity and higher numbers of 3- point shots, turnovers and fouls with low performance and regularity. These results should help coaches and sports managers design strategies that improve performance and recruiting for their teams.En este trabajo se analiza la relación entre rendimiento y regularidad para evitar el problema que supone el uso de medias en las estadísticas deportivas dada su sensibilidad a los datos extremos. El objetivo de este trabajo es establecer qué estadísticas iscriminan entre el alto y bajo rendimiento y regularidad de los jugadores de baloncesto utilizando un índice rendimiento-regularidad. La muestra está compuesta por jugadores de la liga profesional española de baloncesto, Liga ACB, de 2014-2015. Dividimos la muestra en jugadores con bajo, medio y alto rendimiento y regularidad a través de un método k-means y un análisis discriminante asociando altos números de rebotes, asistencias y robos con alto rendimiento y regularidad y mayores números de tiros de 3 puntos, pérdidas de balón y faltas con bajo rendimiento y regularidad. Estos resultados deberían ayudar a entrenadores y gestores deportivos a diseñar estrategias que mejoren el rendimiento y la captación de sus equipos.Proyecto ECO2013-47009-PProyecto P11-SEJ-798

Usefulness of bioelectrical impedance analysis for monitoring patients with refractory ascites

Background: bioelectrical impedance analysis is a technique for the determination of the hydropic component. The hydropic component, determined by blood volume, could be a reflection of the hemodynamic situation. This study aimed to evaluate the usefulness of peripheral bioelectrical impedance analysis (BIA) for the prediction of hemodynamic changes in large-volume paracentesis and prognosis. Methods: this was a proof-of-concept prospective study of 14 patients with liver cirrhosis and refractory ascites. Peripheral bioimpedance was measured three times using a portable device, IVOL®, before and after large-volume paracentesis, at different frequencies (5, 10, 20, 50, 100 and 200 kHz). Consequently, resistance, reactance and phase angle were obtained, both pre- and post-paracentesis (the difference between them was defined as Δ). Results: the mean age of patients was 62.2 ± 9.6 years, the Child-Pugh was 8.4 ± 1.3 and the MELD score was 15.2 ± 3.9. A direct correlation between the extraction of ascitic fluid and Δresistance (10 kHz [r = 0.722; n = 12; p = 0.008], 20 kHz [r = 0.658; n = 12; p = 0.020] and 50 kHz [r = 0.519; n = 14; p = 0.057]) was observed. The presence of edema was related to lower values of both pre-paracentesis resistance (10 Hz [23.9 ± 8 vs 32.2 ± 4; p = 0.043]) and phase angle (5 kHz [-1.9 ± 2.8 vs 5.9 ± 7.3; p = 0.032]). Pre-paracentesis phase angle was directly correlated with the decline in blood pressure after paracentesis at lower frequencies (5 kHz [r = 0.694; n = 13; p = 0.008] and 10 kHz [r = 0.661; n = 13; p = 0.014]). Lower frequencies of Δphase-angle impacted on patient prognosis (5 kHz [-8.6 ± 5 vs -2.5 ± 2.7; p = 0.021]), patients with Δphase-angle 5 kHz > -4 had a higher rate of mortality (83.3% [5/6] vs 0% [0/6]; logRank 7.306, p = 0.007). Δresistance values were associated with overt HE at six months (10 kHz [4.9 ± 2.5 vs -0.4 ± 4.7; p = 0.046]). Conclusions: in conclusion, a significant correlation between peripheral impedance and hemodynamic changes was found. Impedance was also significantly related to prognosis and overt hepatic encephalopathy

A new species of Schizopera (Copepoda: Harpacticoida: Miraciidae) from Colombia

Objective. The present contribution aims at the description of a new species of the genus Schizopera. Materials and methods. Water samples were collected in littoral areas with mangrove and macrophytes, and in the limnetic zone. Twenty five liters of water were taken. Water samples were filtered with a zooplankton net (45μm) and preserved in 70% ethanol. The filtered samples were concentrated to 100 ml and examined in a Bogorov camera. Copepods were separated. Observations and drawings of S. evelynae sp. nov. were made at a magnification of 1000X. Results. Schizopera evelynae sp. nov. seems to be closely related to S. giselae Jiménez -Álvarez 1988 and to S. pratensis Noodt 1958 based on the armature formula of P1-P4, but can be separated from these two species based on the relative length of P1ENP, length/width ratio of P1ENP2, relative length of the outer proximal and distal spines on P4EXP3, shape of the exopod and relative length of the exopodal setae of the female P5, shape and length/width ratio of the male P2ENP2, and male P5 baseoendopodal lobe:exopod length ratio. A key to the species of Schizopera from America is given. Conclusion. A new species of the genus Schizopera is described. The Colombian material shares most characters with S. giselae and S. pratensis

Percepción del nivel satisfacción con el desempeño por competencias de los médicos egresados del programa Medicina y Cirugía de la Universidad Tecnológica de Pereira

En este trabajo se determinaron las percepciones del nivel de satisfacción con el desempeño profesional por competencias de los médicos egresados del Programa de Medicina y Cirugía (PMC) como estrategia para entregar insumos a los procesos de acreditación y modernización curricular. Para tal efecto se utilizó un instrumento de evaluación basado en el Proyecto Tuning América Latina y la propuesta de competencias de la Asociación Colombiana de Facultades de Medicina (ASCOFAME), diligenciado por la totalidad de los estudiantes de XI semestre, internos, docentes y enfermeras que hacen parte del internado en el hospital Universitario San Jorge. Esta información permitió identificar en las 63 competencias las 11 mejor y las 15 peor evaluadas por los cuatro estamentos, para la búsqueda de fortalezas y debilidades del plan de estudios y relacionar los datos con el perfil profesional y ocupacional que se necesita en el contexto actual