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Pericial sobre les causes de les anomalies manifestades en un aparcament al Pla de Palau de Mataró (el Maresme)

  • Zamora i Mestre, Joan-Lluís
  • Gimferrer Vilaplana, Xavier
Informe sol·licitat per l'empresa CONSTRUCTORA sobre les anomalies manifestades en el tram del junt de dilatació dels sostres, Anomalia presentada en un junt de dilatació d'un sostre d'un aparcament soterrani.

Morphological changes, beach inundation and overwash caused by an extreme storm on a low-lying embayed beach bounded by a dune system (NW Mediterranean)

  • Duran, Ruth
  • Guillén Aranda, Jorge
  • Ruiz García, Antonio
  • Jiménez Quintana, José Antonio
  • Sagrista, Enric
The geomorphological evolution of a low-lying, micro-tidal sandy beach in the western Mediterranean, Pals beach, was characterized using airborne Light Detection and Ranging (LiDAR) data. Data were collected in prior to and six months after the impact of an extreme storm with a return period of approx. 50 years, with the aim of characterizing the beach's response to the storm. The use of repeated high-resolution topographic data to quantify beach geomorphic changes has allowed assessment of the accuracy of different proxies for estimating beach volume changes. Results revealed that changes in the shoreline position cannot accurately reproduce beach volume changes on low-lying beaches where overwash processes are significant. Observations also suggested that volume estimations from beach profiles do not accurately represent subaerial volume changes at large profile distances on beaches with significant alongshore geomorphological variability. Accordingly, the segmentation of the beach into regularly spaced bins is proposed to assess alongshore variations in the beach volume with the accuracy of the topographic data. The morphological evolution of Pals beach during the study period showed a net shoreline retreat (- 4 m) and a significant sediment gain on the subaerial beach (+ 7.5 m3/m). The net gain of sediment is mostly due to the impact of the extreme storm, driving significant overwash processes that transport sediment landwards, increasing volume on the backshore and dunes. The increase of volume on the foreshore and the presence of cuspate morphologies along the shoreline also evidence post-storm beach recovery. Observed morphological changes exhibit a high variability along the beach related to variations in beach morphology. Changes in the morphology and migration of megacusps result in a high variability in the shoreline position and foreshore volume changes. On the other hand, larger morphological changes on the backshore and larger inundation distances occur when the beach and the dunes are lower, favouring the dominance of overwash. The observed storm-induced morphological changes differ from predicted beach storm impacts because of spatial and temporal variations in the beach morphology, suggesting that detailed morphological parameters and indicators used for predicting beach vulnerability to storms should be regularly updated in order to represent the pre-storm beach conditions. Finally, observed morphological changes in Pals Bay evidenced a different behaviour between natural and urban areas, with better post-storm beach recovery on natural areas where the beach is not artificially narrowed., Peer Reviewed

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  • Bosch Roura, Lluís
  • Casañas Artigas, Francesc

The normalized Laplacian spectrum of subdivisions of a graph

  • Xie, Pinchen
  • Zhang, Zhongzhi
  • Comellas Padró, Francesc de Paula
Determining and analyzing the spectra of graphs is an important and exciting research topic in mathematics science and theoretical computer science. The eigenvalues of the normalized Laplacian of a graph provide information on its structural properties and also on some relevant dynamical aspects, in particular those related to random walks. In this paper, we give the spectra of the normalized Laplacian of iterated subdivisions of simple connected graphs. As an example of application of these results we find the exact values of their multiplicative degree-Kirchhoff index, Kemeny's constant and number of spanning trees.

Group Prediction in Collaborative Learning

  • Meseguer Pallarès, Roc
  • Medina Medina, Esunly
  • Royo Vallés, María Dolores
  • Navarro Moldes, Leandro
  • Juárez, Juan Pablo
We propose an approach for predicting group formations, to address the problem of automating the incorporation of group awareness into CSCL applications. Contextual information can enable the construction of applications that effectively assist the group members to automatically communicate in synchronous and collocated collaborative learning activities. We used data traces collected from the study of students’ behavior to train and test an intelligent system. Results have shown that context-information can be effectively used as a basis for a middleware for a dynamic group management. Inferring group membership is technically viable and can be used in real world settings.

Alberto Piwonka : en el cruce de las ideas de la modernidad en Chile

  • Molina Baeza, Cristóbal, 1976-
This thesis proposes the study of the intersection of ideas comprised in the academic and architectural work of Alberto Piwonka in the cultural, social, technological, and aesthetic context of Chile during the forties, fifties, and sixties. This intersection comes, in large part, from the transfer of the concepts developed by Piwonka in his teachings in the Pure Composition Studio (also known as Preliminary Studio, Pre-Architecture, Plastic, or Basic Design) in the School of Architecture at the Universidad Católica and the exercise of his professional practice. In Piwonka's architectural projects, the buildings and the area of intervention around them tend to be the place of the application, congregation, integration, and synthesis of these ideas. Likewise, the idea of formal abstraction in the field of non-figurative art and design in a broad sense appears strongly in his work, oriented toward the understanding of the project as a place where ideas converge, where architecture, construction technique, material finishings, and the application of color co-exist with the design of objects and furniture, typography, reliefs, murals, or landscaping. On one hand, the studios that have been grouped under the name of Pure Composition in this work come from a particular assimilation of the Vorkurs course at the Bauhaus and the subsequent expansion of this teaching in the United States in the national context. While this studio was instituted at the Universidad Católica by Alberto Cruz Covarrubias and Alberto Piwonka in 1947, its teachings would later be systematized in the curriculum reform two years later, where Piwonka would actively participate along with a group of professors committed to architecture and modern art. This process would result in a further modernization of teaching and was perfectly consolidated once Sergio Larrain García-Moreno became dean of the School of Architecture in 1953. At the end of the previous year Piwonka had made contact with Josef Albers, who had taught the Vorkurs at the Bauhaus and at that time directed the Design Department of Yale University. Piwonka accompanied Albers during his academic residency at the School of Architecture of the Universidad Católica in 1953, when the German taught the Pure Composition studio with him in the first two years of the curriculum. Piwonka would be the one to continue his teaching until 1967 at the School of Architecture. He would also promote the creation of the new School of Art in 1958, of which he was the first director, a fact that would link him closely to the most important plastic artists residing in Chile, and the area of Design in 1965, which would be the origin of the School of Design of the university and where he would remain on tenure virtually until his death. On the other hand, from Piwonka¿s work arises an interesting position in the exercise of a professional architecture practice like a stream that runs parallel to his academic activity. This professional approach is complemented by his visual formation and appears to establish a kind of methodology that can be recognized in the criteria with which Piwonka deals with the plastic resolution of his buildings. The sense of form that Piwonka proposes is essentially visual. In his architecture, the criteria of spatial composition tends to be present in his definition of the buildings¿ form and the organization of their structural elements, which relate material and building solutions at the different scales and dimensions of the project. His buildings seem to evoke the idea of abstraction both through their formal resolution and the relationship they establish with the place and landscape that surrounds them in a situation of declared contrast., Esta tesis propone el estudio del cruce de las ideas comprendidas en el trabajo académico y arquitectónico realizado por Alberto Piwonka en el contexto cultural, social, tecnológico y estético de Chile durante las décadas del cuarenta, cincuenta y sesenta. Ese cruce proviene, en parte importante, del traspaso de los conceptos desarrollados por Piwonka en la enseñanza del taller de Composición Pura ,conocido también con los nombres de taller Preliminar, Composición pre-arquitectónica, Plástica o Diseño Básico en la Escuela de Arquitectura de la Universidad Católica y el ejercicio de su práctica profesional. En los proyectos arquitectónicos realizados por Piwonka, los edificios y el área de intervención en torno a ellos suelen ser el lugar de aplicación, encuentro, integración y síntesis de esas ideas. Asimismo en su trabajo aparece con fuerza la idea de abstracción formal en el campo del arte no figurativo y el diseño en un sentido amplio, orientados hacia el entendimiento del proyecto como lugar de convergencia de ideas, donde arquitectura, técnica constructiva, acabados y terminaciones materiales, y la aplicación del color, coexisten con el diseño de objetos y mobiliarios, tipografías, relieves, murales o el paisajismo. Por una parte, los talleres que se han agrupado en este trabajo con el nombre de Composición Pura, provienen de una particular asimilación del curso Vorkurs en la Bauhaus y la posterior profundización de esa enseñanza en Estados Unidos en el contexto nacional. Si bien ese taller fue iniciado en la Universidad Católica por Alberto Cruz Covarrubias y Alberto Piwonka en 1947, esa enseñanza se sistematizará luego de la reforma a los planes de estudio de esa Escuela dos años más tarde, donde Piwonka participará activamente junto al grupo de profesores más comprometidos con la arquitectura y el arte moderno. Ese proceso derivará en una modernización mayor de la enseñanza, cuando se consolida a cabalidad el proyecto académico una vez que Sergio Larrain García-Moreno asuma como decano de la Facultad de Arquitectura en 1953. Al final del año anterior Piwonka trabará contacto con Josef Albers, quien había impartido el Vorkurs en la Bauhaus y que por esos años dirigía el Departamento de Diseño en la Universidad de Yale. Piwonka acompañará a Albers en su estadía académica en la Escuela de Arquitectura de la Universidad Católica en 1953, cuando el alemán dicte junto con él los talleres de Composición Pura en los dos primeros años de la carrera. Piwonka será quien dará continuidad a esa enseñanza hasta 1967 en la Escuela de Arquitectura, y promoverá además la creación de la nueva Escuela de Arte en 1958, de la que fue su primer director, hecho que lo vinculará estrechamente con los más importantes artistas plásticos radicados en Chile, y de la línea de Diseño en 1965, que será el origen de la Escuela de Diseño en esa misma Universidad, y donde permanecerá como académico prácticamente hasta su muerte. Por otra parte, del trabajo de Piwonka se deriva una interesante postura en el ejercicio de la práctica profesional de la arquitectura, como una vertiente que corre en paralelo a su actividad académica. Esa línea profesional es complementada con su preparación visual, y parece establecer una suerte de metodología, que puede ser reconocible en los criterios con que Piwonka enfrenta la resolución plástica de los edificios. El sentido de la forma que propone Piwonka es esencialmente visual. En su arquitectura, los criterios de composición espacial suelen estar presentes en la definición de la forma de los edificios y en la organización de sus elementos constructivos, que relacionan soluciones materiales y constructivas en las diferentes escalas y dimensiones del proyecto. Sus edificios parecen evocar la idea de abstracción, tanto en su resolución formal como en la relación que establecen con el lugar y el paisaje que los rodea, en una situación de declarado contraste.

Task space consensus in networks of heterogeneous and uncertain robotic systems with variable time-delays

  • Nuño, Emmanuel
  • Aldana, Carlos I.
  • Basañez Villaluenga, Luis
This work deals with the leader-follower and the leaderless consensus problems in networks of multiple robot manipulators. The robots are non-identical, kinematically different (heterogeneous), and their physical parameters are uncertain. The main contribution of this work is a novel controller that solves the two consensus problems, in the task space, with the following features: it estimates the kinematic and the dynamic physical parameters; it is robust to interconnecting variable-time delays; it employs the singularity-free unit-quaternions to represent the orientation; and, using energy-like functions, the controller synthesis follows a constructive procedure. Simulations using a network with four heterogeneous manipulators illustrate the performance of the proposed controller., Peer Reviewed

Plan de Empresa de una fábrica de captadores solares

  • Rodríguez Lallana, Olga
El presente proyecto presenta un plan de negocio de una empresa dedicada a la fabricación de captadores solares, suministro e instalación de los componentes necesarios para realizar instalaciones solares térmicas, que estará situada en el Vallés Occidental. El Código Técnico en Edificación (CTE) (2006) exige que en determinadas condiciones los edificios nuevos, y de rehabilitación, incorporen un sistema de energía solar de baja temperatura. Para su cumplimiento cabía esperar un incremento de las necesidades de captadores solares. En el proyecto se observa la evolución que ha tenido este mercado. Actualmente el crecimiento económico, en general, y en el sector de la construcción en particular no se ha reanudado en Europa, pero empieza a notarse una ligera activación. Aunque la situación no es aún demasiado alentadora, es un buen momento para prepararse para la próxima fase de crecimiento. Para la realización de este plan de negocio se ha estudiado el entorno de la empresa, especialmente la situación actual de la energía y el mercado de captadores solares. Posteriormente se ha detallado el marketing mix y se han desarrollado las estrategias necesarias para posicionarse en el mercado. A continuación se han diseñado los procesos precisos para llevar a cabo la actividad y la planificación temporal de la puesta en marcha. A continuación se han determinado los medios de producción necesarios para llevar a cabo la fabricación, así como la estructura organizativa de la empresa y las características del personal. Finalmente se ha analizado la viabilidad de la empresa en un horizonte temporal de cinco años y varios posibles escenarios, a través de la cuenta de Pérdidas y Ganancias, previsión de tesorería y balances de situación, para terminar calculando los ratios y la rentabilidad de la inversión.

Solution Approach for a Large-Scale Personnel Transport System for a Large Company in Latin America

  • Garzón Garnica, Eduardo Arturo
  • Caballero Morales, Santiago Omar
  • Martínez Flores, José Luis
Purpose: The present paper focuses on the modelling and solution of a large-scale personnel transportation system in Mexico where many routes and vehicles are currently used to service 532 points. The routing system proposed can be applied to many cities in the Latin-American region. Design/methodology/approach: This system was modelled as a VRP model considering the use of real-world transit times, and the fact that routes start at the farthest point from the destination center. Experiments were performed on different sized sets of service points. As the size of the instances was increased, the performance of the meta-heuristic method was assessed in comparison with the results of an exact algorithm, the results remaining very close between both. When the size of the instance was full-scale and the exact algorithm took too much time to solve the problem, then the meta-heuristic algorithm provided a feasible solution. Supported by the validation with smaller scale instances, where the difference between both solutions was close to a 6%, the full–scale solution obtained with the meta-heuristic algorithm was considered to be within that same range. This solution complies with the optimal number of vehicles. Findings: The proposed modelling and solving method provided a solution that would produce significant savings in the daily operation of the routes. Originality/value: The urban distribution of the cities in Latin America is unique to other regions in the world. The general layout of the large cities in this region includes a small-town center, usually antique, and a somewhat disordered outer region. The lack of a vehicle-centered, Peer Reviewed

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