791 resultados para Multicriteria Collaborative Filtering
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In this work we address a scenario where 3D content is transmitted to a mobile terminal with 3D display capabilities. We consider the use of 2D plus depth format to represent the 3D content and focus on the generation of synthetic views in the terminal. We evaluate different types of smoothing filters that are applied to depth maps with the aim of reducing the disoccluded regions. The evaluation takes into account the reduction of holes in the synthetic view as well as the presence of geometrical distortion caused by the smoothing operation. The selected filter has been included within an implemented module for the VideoLan Client (VLC) software in order to render 3D content from the 2D plus depth data format.
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Dynamic and Partial Reconfiguration allows systems to change some parts of their hardware at run time. This feature favours the inclusion of evolutionary strategies to provide optimised solutions to the same problem so that they can be mixed and compared in a way that only the best ones prevail. At the same time, distributed intelligence permits systems to work in a collaborative way to jointly improve their global capabilities. This work presents a combination of both approaches where hardware evolution is performed both at local and network level in order to improve an image filter application in terms of performance, robustness and providing the capacity of avoiding local minimums, which is the main drawback of some evolutionary approaches.
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El análisis de las diferentes alternativas en la planificación y diseño de corredores y trazados de carreteras debe basarse en la correcta definición de variables territoriales que sirvan como criterios para la toma de decisión y esto requiere un análisis ambiental preliminar de esas variables de calidad. En España, los estudios de viabilidad de nuevas carreteras y autovías están asociados a una fase del proceso de decisión que se corresponde con el denominado Estudio Informativo, el cual establece condicionantes físicos, ambientales, de uso del suelo y culturales que deben ser considerados en las primeras fases de la definición del trazado de un corredor de carretera. Así, la metodología más frecuente es establecer diferentes niveles de capacidad de acogida del territorio en el área de estudio con el fin de resumir las variables territoriales en mapas temáticos y facilitar el proceso de trazado de las alternativas de corredores de carretera. El paisaje es un factor limitante a tener en cuenta en la planificación y diseño de carreteras y, por tanto, deben buscarse trazados más sostenibles en relación con criterios estéticos y ecológicos del mismo. Pero este factor no es frecuentemente analizado en los Estudios Informativos e incluso, si es considerado, los estudios específicos de la calidad del paisaje (estético y ecológico) y de las formas del terreno no incorporan las recomendaciones de las guías de trazado para evitar o reducir los impactos en el paisaje. Además, los mapas de paisaje que se generan en este tipo de estudios no se corresponden con la escala de desarrollo del Estudio Informativo (1:5.000). Otro déficit común en planificación de corredores y trazados de carreteras es que no se tiene en cuenta la conectividad del paisaje durante el proceso de diseño de la carretera para prevenir la afección a los corredores de fauna existentes en el paisaje. Este déficit puede originar un posterior efecto barrera en los movimientos dispersivos de la fauna y la fragmentación de sus hábitats debido a la ocupación parcial o total de las teselas de hábitats con importancia biológica para la fauna (o hábitats focales) y a la interrupción de los corredores de fauna que concentran esos movimientos dispersivos de la fauna entre teselas. El objetivo principal de esta tesis es mejorar el estudio del paisaje para prevenir su afección durante el proceso de trazado de carreteras, facilitar la conservación de los corredores de fauna (o pasillos verdes) y la localización de medidas preventivas y correctoras en términos de selección y cuantificación de factores de idoneidad a fin de reducir los impactos visuales y ecológicos en el paisaje a escala local. Concretamente, la incorporación de valores cuantitativos y bien justificados en el proceso de decisión permite incrementar la transparencia en el proceso de diseño de corredores y trazados de carreteras. Con este fin, se han planteado cuatro preguntas específicas en esta investigación (1) ¿Cómo se seleccionan y evalúan los factores territoriales limitantes para localizar una nueva carretera por los profesionales españoles de planificación del territorio en relación con el paisaje? (2) ¿Cómo pueden ser definidos los corredores de fauna a partir de factores del paisaje que influyen en los movimientos dispersivos de la fauna? (3) ¿Cómo pueden delimitarse y evaluarse los corredores de fauna incluyendo el comportamiento parcialmente errático en los movimientos dispersivos de la fauna y el efecto barrera de los elementos antrópicos a una escala local? (4) ¿Qué y cómo las recomendaciones de diseño de carreteras relacionadas con el paisaje y las formas del terreno pueden ser incluidas en un modelo de Sistemas de Información Geográfica (SIG) para ayudar a los ingenieros civiles durante el proceso de diseño de un trazado de carreteras bajo el punto de vista de la sostenibilidad?. Esta tesis doctoral propone nuevas metodologías que mejoran el análisis visual y ecológico del paisaje utilizando indicadores y modelos SIG para obtener alternativas de trazado que produzcan un menor impacto en el paisaje. Estas metodologías fueron probadas en un paisaje heterogéneo con una alta tasa de densidad de corzo (Capreolus capreolus L.), uno de los grandes mamíferos más atropellados en la red de carreteras españolas, y donde está planificada la construcción de una nueva autovía que atravesará la mitad del área de distribución del corzo. Inicialmente, se han analizado las variables utilizadas en 22 estudios de proyectos de planificación de corredores de carreteras promovidos por el Ministerio de Fomento entre 2006 y 2008. Estas variables se agruparon según condicionantes físicos, ambientales, de usos del suelo y culturales con el fin de comparar los valores asignados de capacidad de acogida del territorio a cada variable en los diferentes estudios revisados. Posteriormente, y como etapa previa de un análisis de conectividad, se construyó un mapa de resistencia de los movimientos dispersivos del corzo en base a la literatura y al juicio de expertos. Usando esta investigación como base, se le asignó un valor de resistencia a cada factor seleccionado para construir la matriz de resistencia, ponderándolo y combinándolo con el resto de factores usando el proceso analítico jerárquico y los operadores de lógica difusa como métodos de análisis multicriterio. Posteriormente, se diseñó una metodología SIG para delimitar claramente la extensión física de los corredores de fauna de acuerdo a un valor umbral de ancho geométrico mínimo, así como la existencia de múltiples potenciales conexiones entre cada par de teselas de hábitats presentes en el paisaje estudiado. Finalmente, se realizó un procesado de datos Light Detection and Ranging (LiDAR) y un modelo SIG para calcular la calidad del paisaje (estético y ecológico), las formas del terreno que presentan características similares para trazar una carretera y la acumulación de vistas de potenciales conductores y observadores de los alrededores de la nueva vía. Las principales contribuciones de esta investigación al conocimiento científico existente en el campo de la evaluación del impacto ambiental en relación al diseño de corredores y trazados de carreteras son cuatro. Primero, el análisis realizado de 22 Estudios Informativos de planificación de carreteras reveló que los métodos aplicados por los profesionales para la evaluación de la capacidad de acogida del territorio no fue suficientemente estandarizada, ya que había una falta de uniformidad en el uso de fuentes cartográficas y en las metodologías de evaluación de la capacidad de acogida del territorio, especialmente en el análisis de la calidad del paisaje estético y ecológico. Segundo, el análisis realizado en esta tesis destaca la importancia de los métodos multicriterio para estructurar, combinar y validar factores que limitan los movimientos dispersivos de la fauna en el análisis de conectividad. Tercero, los modelos SIG desarrollados Generador de alternativas de corredores o Generator of Alternative Corridors (GAC) y Eliminador de Corredores Estrechos o Narrow Corridor Eraser (NCE) pueden ser aplicados sistemáticamente y sobre una base científica en análisis de conectividad como una mejora de las herramientas existentes para la comprensión el paisaje como una red compuesta por nodos y enlaces interconectados. Así, ejecutando los modelos GAC y NCE de forma iterativa, pueden obtenerse corredores alternativos con similar probabilidad de ser utilizados por la fauna y sin que éstos presenten cuellos de botella. Cuarto, el caso de estudio llevado a cabo de prediseño de corredores y trazado de una nueva autovía ha sido novedoso incluyendo una clasificación semisupervisada de las formas del terreno, filtrando una nube de puntos LiDAR e incluyendo la nueva geometría 3D de la carretera en el Modelo Digital de Superficie (MDS). El uso combinado del procesamiento de datos LiDAR y de índices y clasificaciones geomorfológicas puede ayudar a los responsables encargados en la toma de decisiones a evaluar qué alternativas de trazado causan el menor impacto en el paisaje, proporciona una visión global de los juicios de valor más aplicados y, en conclusión, define qué medidas de integración paisajística correctoras deben aplicarse y dónde. ABSTRACT The assessment of different alternatives in road-corridor planning and layout design must be based on a number of well-defined territorial variables that serve as decision-making criteria, and this requires a high-quality preliminary environmental analysis of those quality variables. In Spain, feasibility studies for new roads and motorways are associated to a phase of the decision procedure which corresponds with the one known as the Informative Study, which establishes the physical, environmental, land-use and cultural constraints to be considered in the early stages of defining road corridor layouts. The most common methodology is to establish different levels of Territorial Carrying Capacity (TCC) in the study area in order to summarize the territorial variables on thematic maps and facilitate the tracing process of road-corridor layout alternatives. Landscape is a constraint factor that must be considered in road planning and design, and the most sustainable layouts should be sought based on aesthetic and ecological criteria. However this factor is not often analyzed in Informative Studies and even if it is, baseline studies on landscape quality (aesthetic and ecological) and landforms do not usually include the recommendations of road tracing guides designed to avoid or reduce impacts on the landscape. The resolution of the landscape maps produced in this type of studies does not comply with the recommended road design scale (1:5,000) in the regulations for the Informative Study procedure. Another common shortcoming in road planning is that landscape ecological connectivity is not considered during road design in order to avoid affecting wildlife corridors in the landscape. In the prior road planning stage, this issue could lead to a major barrier effect for fauna dispersal movements and to the fragmentation of their habitat due to the partial or total occupation of habitat patches of biological importance for the fauna (or focal habitats), and the interruption of wildlife corridors that concentrate fauna dispersal movements between patches. The main goal of this dissertation is to improve the study of the landscape and prevent negative effects during the road tracing process, and facilitate the preservation of wildlife corridors (or green ways) and the location of preventive and corrective measures by selecting and quantifying suitability factors to reduce visual and ecological landscape impacts at a local scale. Specifically the incorporation of quantitative and well-supported values in the decision-making process provides increased transparency in the road corridors and layouts design process. Four specific questions were raised in this research: (1) How are territorial constraints selected and evaluated in terms of landscape by Spanish land-planning practitioners before locating a new road? (2) How can wildlife corridors be defined based on the landscape factors influencing the dispersal movements of fauna? (3) How can wildlife corridors be delimited and assessed to include the partially erratic movements of fauna and the barrier effect of the anthropic elements at a local scale? (4) How recommendations of road design related to landscape and landforms can be included in a Geographic Information System (GIS) model to aid civil engineers during the road layout design process and support sustainable development? This doctoral thesis proposes new methodologies that improve the assessment of the visual and ecological landscape character using indicators and GIS models to obtain road layout alternatives with a lower impact on the landscape. These methodologies were tested on a case study of a heterogeneous landscape with a high density of roe deer (Capreolus capreolus L.) –one of the large mammals most commonly hit by vehicles on the Spanish road network– and where a new motorway is planned to pass through the middle of their distribution area. We explored the variables used in 22 road-corridor planning projects sponsored by the Ministry of Public Works between 2006 and 2008. These variables were grouped into physical, environmental, land-use and cultural constraints for the purpose of comparing the TCC values assigned to each variable in the various studies reviewed. As a prior stage in a connectivity analysis, a map of resistance to roe deer dispersal movements was created based on the literature and experts judgment. Using this research as a base, each factor selected to build the matrix was assigned a resistance value and weighted and combined with the rest of the factors using the analytic hierarchy process (AHP) and fuzzy logic operators as multicriteria assessment (MCA) methods. A GIS methodology was designed to clearly delimit the physical area of wildlife corridors according to a geometric threshold width value, and the multiple potential connections between each pair of habitat patches in the landscape. A Digital Surface Model Light Detection and Ranging (LiDAR) dataset processing and a GIS model was performed to determine landscape quality (aesthetic and ecological) and landforms with similar characteristics for the road layout, and the cumulative viewshed of potential drivers and observers in the area surrounding the new motorway. The main contributions of this research to current scientific knowledge in the field of environmental impact assessment for road corridors and layouts design are four. First, the analysis of 22 Informative Studies on road planning revealed that the methods applied by practitioners for assessing the TCC were not sufficiently standardized due to the lack of uniformity in the cartographic information sources and the TCC valuation methodologies, especially in the analysis of the aesthetic and ecological quality of the landscape. Second, the analysis in this dissertation highlights the importance of multicriteria methods to structure, combine and validate factors that constrain wildlife dispersal movements in the connectivity analysis. Third, the “Generator of Alternative Corridors (GAC)” and “Narrow Corridor Eraser (NCE)” GIS models developed can be applied systematically and on a scientific basis in connectivity analyses to improve existing tools and understand landscape as a network composed of interconnected nodes and links. Thus, alternative corridors with similar probability of use by fauna and without bottlenecks can be obtained by iteratively running GAC and NCE models. Fourth, our case study of new motorway corridors and layouts design innovatively included semi-supervised classification of landforms, filtering of LiDAR point clouds and new 3D road geometry on the Digital Surface Model (DSM). The combined used of LiDAR data processing and geomorphological indices and classifications can help decision-makers assess which road layouts produce lower impacts on the landscape, provide an overall insight into the most commonly applied value judgments, and in conclusion, define which corrective measures should be applied in terms of landscaping, and where.
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This paper presents a work whose objective is, first, to quantify the potential of the triticale biomass existing in each of the agricultural regions in the Madrid Community through a crop simulation model based on regression techniques and multiple correlation. Second, a methodology for defining which area has the best conditions for the installation of electricity plants from biomass has been described and applied. The study used a methodology based on compromise programming in a discrete multicriteria decision method (MDM) context. To make a ranking, the following criteria were taken into account: biomass potential, electric power infrastructure, road networks, protected spaces, and urban nuclei surfaces. The results indicate that, in the case of the Madrid Community, the Campiña region is the most suitable for setting up plants powered by biomass. A minimum of 17,339.9 tons of triticale will be needed to satisfy the requirements of a 2.2 MW power plant. The minimum range of action for obtaining the biomass necessary in Campiña region would be 6.6 km around the municipality of Algete, based on Geographic Information Systems. The total biomass which could be made available in considering this range in this region would be 18,430.68 t.
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Esta Tesis presenta un nuevo método para filtrar errores en bases de datos multidimensionales. Este método no precisa ninguna información a priori sobre la naturaleza de los errores. En concreto, los errrores no deben ser necesariamente pequeños, ni de distribución aleatoria ni tener media cero. El único requerimiento es que no estén correlados con la información limpia propia de la base de datos. Este nuevo método se basa en una extensión mejorada del método básico de reconstrucción de huecos (capaz de reconstruir la información que falta de una base de datos multidimensional en posiciones conocidas) inventado por Everson y Sirovich (1995). El método de reconstrucción de huecos mejorado ha evolucionado como un método de filtrado de errores de dos pasos: en primer lugar, (a) identifica las posiciones en la base de datos afectadas por los errores y después, (b) reconstruye la información en dichas posiciones tratando la información de éstas como información desconocida. El método resultante filtra errores O(1) de forma eficiente, tanto si son errores aleatorios como sistemáticos e incluso si su distribución en la base de datos está concentrada o esparcida por ella. Primero, se ilustra el funcionamiento delmétodo con una base de datosmodelo bidimensional, que resulta de la dicretización de una función transcendental. Posteriormente, se presentan algunos casos prácticos de aplicación del método a dos bases de datos tridimensionales aerodinámicas que contienen la distribución de presiones sobre un ala a varios ángulos de ataque. Estas bases de datos resultan de modelos numéricos calculados en CFD. ABSTRACT A method is presented to filter errors out in multidimensional databases. The method does not require any a priori information about the nature the errors. In particular, the errors need not to be small, neither random, nor exhibit zero mean. Instead, they are only required to be relatively uncorrelated to the clean information contained in the database. The method is based on an improved extension of a seminal iterative gappy reconstruction method (able to reconstruct lost information at known positions in the database) due to Everson and Sirovich (1995). The improved gappy reconstruction method is evolved as an error filtering method in two steps, since it is adapted to first (a) identify the error locations in the database and then (b) reconstruct the information in these locations by treating the associated data as gappy data. The resultingmethod filters out O(1) errors in an efficient fashion, both when these are random and when they are systematic, and also both when they concentrated and when they are spread along the database. The performance of the method is first illustrated using a two-dimensional toymodel database resulting fromdiscretizing a transcendental function and then tested on two CFD-calculated, three-dimensional aerodynamic databases containing the pressure coefficient on the surface of a wing for varying values of the angle of attack. A more general performance analysis of the method is presented with the intention of quantifying the randomness factor the method admits maintaining a correct performance and secondly, quantifying the size of error the method can detect. Lastly, some improvements of the method are proposed with their respective verification.
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Cover crop selection should be oriented to the achievement of specific agrosystem benefits. The covercrop, catch crop, green manure and fodder uses were identified as possible targets for selection. Theobjective was to apply multi-criteria decision analysis to evaluate different species (Hordeum vulgareL., Secale cereale L., ×Triticosecale Whim, Sinapis alba L., Vicia sativa L.) and cultivars according to theirsuitability to be used as cover crops in each of the uses. A field trial with 20 cultivars of the five specieswas conducted in Central Spain during two seasons (October?April). Measurements of ground cover, cropbiomass, N uptake, N derived from the atmosphere, C/N, dietary fiber content and residue quality werecollected. Aggregation of these variables through utility functions allowed ranking species and cultivarsfor each usage. Grasses were the most suitable for the cover crop, catch crop and fodder uses, while thevetches were the best as green manures. The mustard attained high ranks as cover and catch crop the firstseason, but the second decayed due to low performance in cold winters. Mustard and vetches obtainedworse rankings than grasses as fodder. Hispanic was the most suitable barley cultivar as cover and catchcrop, and Albacete as fodder. The triticale Titania attained the highest rank as cover and catch crop andfodder. Vetches Aitana and BGE014897 showed good aptitudes as green manures and catch crops. Thisanalysis allowed comparison among species and cultivars and might provide relevant information forcover crops selection and management.
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To investigate the nature of plasticity in the adult visual system, perceptual learning was measured in a peripheral orientation discrimination task with systematically varying amounts of external (environmental) noise. The signal contrasts required to achieve threshold were reduced by a factor or two or more after training at all levels of external noise. The strong quantitative regularities revealed by this novel paradigm ruled out changes in multiplicative internal noise, changes in transducer nonlinearites, and simple attentional tradeoffs. Instead, the regularities specify the mechanisms of perceptual learning at the behavioral level as a combination of external noise exclusion and stimulus enhancement via additive internal noise reduction. The findings also constrain the neural architecture of perceptual learning. Plasticity in the weights between basic visual channels and decision is sufficient to account for perceptual learning without requiring the retuning of visual mechanisms.
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Objective: To compare the resource implications and short term outcomes of extracorporeal membrane oxygenation and conventional management for term babies with severe respiratory failure.
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In 1995, the National Library of Medicine (NLM) and the Public Health Service (PHS) recommended that special attention be given to the information needs of unaffiliated public health professionals. In response, the National Network of Libraries of Medicine (NN/LM) Greater Midwest Region initiated a collaborative outreach program for public health professionals working in rural east and central Iowa. Five public health agencies were provided equipment, training, and support for accessing the Internet. Key factors in the success of this project were: (1) the role of collaborating agencies in the implementation and ongoing success of information access outreach projects; (2) knowledge of the socio-cultural factors that influence the information-seeking habits of project participants (public health professionals); and (3) management of changing or varying technological infrastructures. Working with their funding, personnel from federal, state, and local governments enhanced the information-seeking skills of public health professionals in rural eastern and central Iowa communities.
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Paper submitted to ICERI2013, the 6th International Conference of Education, Research and Innovation, Seville (Spain), November 18-20, 2013.
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In this letter, a new approach for crop phenology estimation with remote sensing is presented. The proposed methodology is aimed to exploit tools from a dynamical system context. From a temporal sequence of images, a geometrical model is derived, which allows us to translate this temporal domain into the estimation problem. The evolution model in state space is obtained through dimensional reduction by a principal component analysis, defining the state variables, of the observations. Then, estimation is achieved by combining the generated model with actual samples in an optimal way using a Kalman filter. As a proof of concept, an example with results obtained with this approach over rice fields by exploiting stacks of TerraSAR-X dual polarization images is shown.
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Virtual and remote laboratories (VRLs) are e-learning resources that enhance the accessibility of experimental setups providing a distance teaching framework which meets the student's hands-on learning needs. In addition, online collaborative communication represents a practical and a constructivist method to transmit the knowledge and experience from the teacher to students, overcoming physical distance and isolation. This paper describes the extension of two open source tools: (1) the learning management system Moodle, and (2) the tool to create VRLs Easy Java Simulations (EJS). Our extension provides: (1) synchronous collaborative support to any VRL developed with EJS (i.e., any existing VRL written in EJS can be automatically converted into a collaborative lab with no cost), and (2) support to deploy synchronous collaborative VRLs into Moodle. Using our approach students and/or teachers can invite other users enrolled in a Moodle course to a real-time collaborative experimental session, sharing and/or supervising experiences at the same time they practice and explore experiments using VRLs.
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Power line interference is one of the main problems in surface electromyogram signals (EMG) analysis. In this work, a new method based on the stationary wavelet packet transform is proposed to estimate and remove this kind of noise from EMG data records. The performance has been quantitatively evaluated with synthetic noisy signals, obtaining good results independently from the signal to noise ratio (SNR). For the analyzed cases, the obtained results show that the correlation coefficient is around 0.99, the energy respecting to the pure EMG signal is 98–104%, the SNR is between 16.64 and 20.40 dB and the mean absolute error (MAE) is in the range of −69.02 and −65.31 dB. It has been also applied on 18 real EMG signals, evaluating the percentage of energy respecting to the noisy signals. The proposed method adjusts the reduction level to the amplitude of each harmonic present in the analyzed noisy signals (synthetic and real), reducing the harmonics with no alteration of the desired signal.