21 resultados para WORK METHODS
em Universidad Politécnica de Madrid
Resumo:
La tesis plantea el estudio de la figura de Fernando García Mercadal (1896- 1985) y su obra, en el contexto del proyecto moderno perteneciente a la racionalidad teórica colectiva de la segunda generación del Movimiento Moderno en Europa, y explora la vida y circunstancias de un arquitecto que aunque nacido en el XIX, trajo la modernidad a España. El Movimiento Moderno en España, se articula en las décadas de los años 20 y 30 a través del GATEPAC y un grupo de arquitectos racionalistas en Madrid que Carlos Flores denomina Generación del 1925. Fernando García Mercadal, primero de su promoción en 1921 y pensionado en Roma, pertenece a ambos y pronto se convierte junto con Josep Lluis Sert, en una de las figuras más relevantes del panorama moderno español. Único miembro fundador del GATEPAC que había nacido en el siglo XIX, publica habitualmente en la revista AC (1931-1937), y en la revista Arquitectura desde 1920. Organiza en la Residencia de Estudiantes, entre 1928 y 1932, un famoso ciclo de Conferencias que imparten Le Corbusier, Mendelsohn, Van Doesburg, Gropius y Giedion. También asiste a la reunión constituyente de los CIAM en La Sarraz en 1928, al CIAM II en Frankfurt en 1929 y al CIAM III en Bruselas en 1930. Fue profesor en la Escuela de Arquitectura de Madrid y Arquitecto Jefe de la Oficina de Urbanismo y de Parques y Jardines del Ayuntamiento de Madrid, cargo al que accede por oposición en 1932. Tras la guerra fue depurado e inhabilitado profesionalmente, hasta que en 1946 comienza a trabajar en el Departamento de Arquitectura del I.N.P. donde continúa hasta los años 70. En 1979 es nombrado Académico de número de la Real Academia de Bellas Artes de San Fernando y muere en Madrid en 1985. Estos son los datos conocidos y aunque en la tesis se aportan nuevos datos inéditos, es en las premisas para su interpretación donde este trabajo de investigación pone el acento. En la historiografía de nuestra arquitectura moderna, pervive una tendencia a suponer una desconexión entre la vanguardia arquitectónica en los años 20 y 30 y el movimiento moderno internacional. El manto de silencio que cayó sobre la generación anterior a la guerra, una vez terminada esta, contribuye a reforzar la idea, cuyo origen y causas exceden el ámbito de trabajo, aunque se tratarán tangencialmente por ser ineludible hacerlo. La tesis pone en cuestión ese planteamiento desde el convencimiento fundamentado en los datos y en la consulta de fuentes originales, que la arquitectura española anterior a la guerra, aun con las circunstancias particulares del país, estuvo en sintonía con la europea, siendo esta la hipótesis de partida de la investigación. Las aportaciones más significativas que, a mi entender, presenta la tesis doctoral, y tienen mayor originalidad, son las siguientes; 1.Puesta en valor de la arquitectura de FGM, antes y después de la guerra, abandonando la idea de su supuesta renuncia a las ideas modernas a partir de los 30; 2. Puesta en valor, con aportación de datos concretos, de la Intensa relación mantenida por FGM y otros arquitectos españoles del Movimiento Moderno con los arquitectos de igual tendencia en el resto de Europa, a través de contactos recíprocos y continuos; 3. Estudio de la obra de FGM en el marco del Movimiento Moderno como una nueva arquitectura basada no tanto en la epidermis, como en una forma de hacer y encarar los problemas donde el proceso es tan importante como el resultado; con el Urbanismo como una nueva ciencia, y con el desarrollo de nuevos programas funcionales acordes a las necesidades de la sociedad contemporánea como el Rincón de Goya y el Hospital de Zaragoza. Se manejan tres métodos de trabajo. Los dos primeros aportan un nuevo enfoque al análisis crítico de FGM y su obra, situándole en el contexto internacional, además del español. El tercero, de carácter instrumental, permite el manejo y sistematización de la documentación. El primer método, consiste en aplicar el criterio generacional de Pevsner o Giedion entre otros, al Movimiento Moderno en España, situando a Fernando García Mercadal como arquitecto de la segunda generación, para hacer un análisis crítico comparativo de su trayectoria con otros arquitectos europeos de la misma, que permita establecer semejanzas y diferencias. El segundo método, complementario al anterior, consiste en estudiar las relaciones internacionales de FGM con las figuras más próximas a él y sus posibles influencias. Por último, y en relación con la documentación de obras y proyectos, se manejan a su vez dos criterios. Para la obra completa, y debido a la inexistencia de originales del Legado García Mercadal, se utiliza con carácter general el material ya publicado, disperso en libros y revistas. En el caso de las cinco obras seleccionadas, se completa con búsqueda en archivos, toma de datos in situ actualizados cuando es posible, y una recopilación de su repercusión en prensa escrita de su momento. ABSTRACT This research study focuses on Fernando Garcia Mercadal (1896-1985) and his work in the context of the Modern project as part of the collective theoretical rationality of the second generation of European Modern architecture. It explores the life and circumstances of the architect, who even though born in 19th century introduced Modern architecture in Spain. Modern architecture (Modern Movement) in Spain covered two decades between 20's and 30's through GATEPAC and a group of rationalists in Madrid that Carlos Flores named “generation of '25”. Fernando Garcia Mercadal, top of his class in 1921 and granted with the scholarship in Rome, belonged to both groups and early in his career he became, along with Josep Lluis Sert, one of the most relevant figures of Modern Architecture in Spain. He was the only member of GATEPAC who was born in 19th century. He frequently published on the magazine “AC” (1931-1937) and on “Arquitecture” magazine since 1920. He organized a series of famous lectures at “Residencia de Estudiantes” (Madrid) between 1928 and 1932 in which Le Corbusier, Mendelsohn, Van Doesburg, Gropius or Giedion took part. He was a member of the constituent meeting of CIAM in La Sarraz in 1928, CIAM II in Frankfurt in 1929 and CIAM III in Brussels in 1930. Mercadal was a teacher at Escuela de Arquitectura de Madrid and the Chief of the Urban Planning, Parks and Gardens Office of the Council of Madrid. He earned his position by public examination in 1932. After the civil war he was disqualified professionally until 1946, when he started working at the Architecture Department at INP until 70's. In 1979 he was elected as an academic member of “Real Academia de Bellas Artes de San Fernando” and later died in 1985. These are the well-known facts and even though this research study provides unpublished facts, it focuses on the premises to interpret them. Throughout the historiographical discourse of Spanish Modern architecture there is a tendency to assume a disconnection between the Avant-garde architecture movements in 20's and 30's and International Modern architecture (Modern Movement). The generation preceding the war remained silent in regard to this issue and once the war was over, they contributed to support the disconnection. The origin and cause exceed the frame of this work, even though they are incidentally commented due to its importance. This research study questions the approach explained above, based on the facts and the original sources. Its first hypothesis states that Spanish architecture before the civil war was, under its own circumstances, in tune with European architecture. The most important and original contributions of this research study are the following under my point of view: 1. To highlight the architecture of FGM, before and after the war, leaving behind his reputed withdrawal of Modernity after 30's; 2. To highlight the intense relationship between FGM and other Modern Spanish architects and other European architects sharing the same ideas, providing detailed facts; 3. Study of FGM's work in the context of Modern architecture as a new architecture based on its know-how and the way problems are faced. The process is as important as the result, not so much based on the dermis; with urban planning as the new science and with the development of the new functional programs based on the needs of contemporary society as in Rincón de Goya or Hospital de Zaragoza. Three work methods are used. The first two add a new vision of the critical analysis related to FGM and his work, positioning him in the international context in addition to Spain. The third is used as an instrument to manage and systematize the documentation. The first method applies the generational criteria of Pevsner or Giedion (among others) to Modern architecture in Spain, positioning Fernando Garcia Mercadal as a second generation architect. A critical-comparative analysis of his career and contemporary European architects is made to establish similarities and differences. The second method is complementary to the previous one and studies the international relationships of FGM with other recognised architects that were close to him and their possible influences. At last, in relation to his works and projects, two methods are used. For the complete works, due to the lack of originals, published material found on magazines and books is used as the source. In the case of the five selected buildings, it is complemented with archive search, onsite data collection when possible and the impact on the press at that moment.
Resumo:
The aim of the present work is to provide an in-depth analysis of the most representative mirroring techniques used in SPH to enforce boundary conditions (BC) along solid profiles. We specifically refer to dummy particles, ghost particles, and Takeda et al. [Prog. Theor. Phys. 92 (1994), 939] boundary integrals. The analysis has been carried out by studying the convergence of the first- and second-order differential operators as the smoothing length (that is, the characteristic length on which relies the SPH interpolation) decreases. These differential operators are of fundamental importance for the computation of the viscous drag and the viscous/diffusive terms in the momentum and energy equations. It has been proved that close to the boundaries some of the mirroring techniques leads to intrinsic inaccuracies in the convergence of the differential operators. A consistent formulation has been derived starting from Takeda et al. boundary integrals (see the above reference). This original formulation allows implementing no-slip boundary conditions consistently in many practical applications as viscous flows and diffusion problems.
Resumo:
Fish communities are a key element in fluvial ecosystems Their position in the top of the food chain and their sensitivity to a whole range of impacts make them a clear objective for ecosystem conservation and a sound indicator of biological integrity. The UE Water Framework Directive includes fish community composition, abundance and structure as relevant elements for the evaluation os biological condition. Several approaches have been proposed for the evaluation of the condition of fish communities, from the bio-indicator concept to the IBI (Index of biotic integrity) proposals. However, the complexity of fish communities and their ecological responses make this evaluation difficult, and we must avoid both oversimplified and extreme analytical procedures. In this work we present a new proposal to define reference conditions in fish communities, discussing them from an ecological viewpoint. This method is a synthetic approach called SYNTHETIC OPEN METHODOLOGICAL FRAMEWORK (SOMF) that has been applied to the rivers of Navarra. As a result, it is recommended the integration of all the available information from spatial, modelling, historical and expert sources, providing the better approach to fish reference conditions, keeping the highest level of information and meeting the legal requirements of the WFD.
Resumo:
Multi-camera 3D tracking systems with overlapping cameras represent a powerful mean for scene analysis, as they potentially allow greater robustness than monocular systems and provide useful 3D information about object location and movement. However, their performance relies on accurately calibrated camera networks, which is not a realistic assumption in real surveillance environments. Here, we introduce a multi-camera system for tracking the 3D position of a varying number of objects and simultaneously refin-ing the calibration of the network of overlapping cameras. Therefore, we introduce a Bayesian framework that combines Particle Filtering for tracking with recursive Bayesian estimation methods by means of adapted transdimensional MCMC sampling. Addi-tionally, the system has been designed to work on simple motion detection masks, making it suitable for camera networks with low transmission capabilities. Tests show that our approach allows a successful performance even when starting from clearly inaccurate camera calibrations, which would ruin conventional approaches.
Resumo:
The implementation of boundary conditions is one of the points where the SPH methodology still has some work to do. The aim of the present work is to provide an in-depth analysis of the most representative mirroring techniques used in SPH to enforce boundary conditions (BC) along solid profiles. We specifically refer to dummy particles, ghost particles, and Takeda et al. [1] boundary integrals. A Pouseuille flow has been used as a example to gradually evaluate the accuracy of the different implementations. Our goal is to test the behavior of the second-order differential operator with the proposed boundary extensions when the smoothing length h and other dicretization parameters as dx/h tend simultaneously to zero. First, using a smoothed continuous approximation of the unidirectional Pouseuille problem, the evolution of the velocity profile has been studied focusing on the values of the velocity and the viscous shear at the boundaries, where the exact solution should be approximated as h decreases. Second, to evaluate the impact of the discretization of the problem, an Eulerian SPH discrete version of the former problem has been implemented and similar results have been monitored. Finally, for the sake of completeness, a 2D Lagrangian SPH implementation of the problem has been also studied to compare the consequences of the particle movement
Resumo:
The development of a global instability analysis code coupling a time-stepping approach, as applied to the solution of BiGlobal and TriGlobal instability analysis 1, 2 and finite-volume-based spatial discretization, as used in standard aerodynamics codes is presented. The key advantage of the time-stepping method over matrix-formulation approaches is that the former provides a solution to the computer-storage issues associated with the latter methodology. To-date both approaches are successfully in use to analyze instability in complex geometries, although their relative advantages have never been quantified. The ultimate goal of the present work is to address this issue in the context of spatial discretization schemes typically used in industry. The time-stepping approach of Chiba 3 has been implemented in conjunction with two direct numerical simulation algorithms, one based on the typically-used in this context high-order method and another based on low-order methods representative of those in common use in industry. The two codes have been validated with solutions of the BiGlobal EVP and it has been showed that small errors in the base flow do not have affect significantly the results. As a result, a three-dimensional compressible unsteady second-order code for global linear stability has been successfully developed based on finite-volume spatial discretization and time-stepping method with the ability to study complex geometries by means of unstructured and hybrid meshes
Resumo:
La planificación pre-operatoria se ha convertido en una tarea esencial en cirugías y terapias de marcada complejidad, especialmente aquellas relacionadas con órgano blando. Un ejemplo donde la planificación preoperatoria tiene gran interés es la cirugía hepática. Dicha planificación comprende la detección e identificación precisa de las lesiones individuales y vasos así como la correcta segmentación y estimación volumétrica del hígado funcional. Este proceso es muy importante porque determina tanto si el paciente es un candidato adecuado para terapia quirúrgica como la definición del abordaje a seguir en el procedimiento. La radioterapia de órgano blando es un segundo ejemplo donde la planificación se requiere tanto para la radioterapia externa convencional como para la radioterapia intraoperatoria. La planificación comprende la segmentación de tumor y órganos vulnerables y la estimación de la dosimetría. La segmentación de hígado funcional y la estimación volumétrica para planificación de la cirugía se estiman habitualmente a partir de imágenes de tomografía computarizada (TC). De igual modo, en la planificación de radioterapia, los objetivos de la radiación se delinean normalmente sobre TC. Sin embargo, los avances en las tecnologías de imagen de resonancia magnética (RM) están ofreciendo progresivamente ventajas adicionales. Por ejemplo, se ha visto que el ratio de detección de metástasis hepáticas es significativamente superior en RM con contraste Gd–EOB–DTPA que en TC. Por tanto, recientes estudios han destacado la importancia de combinar la información de TC y RM para conseguir el mayor nivel posible de precisión en radioterapia y para facilitar una descripción precisa de las lesiones del hígado. Con el objetivo de mejorar la planificación preoperatoria en ambos escenarios se precisa claramente de un algoritmo de registro no rígido de imagen. Sin embargo, la gran mayoría de sistemas comerciales solo proporcionan métodos de registro rígido. Las medidas de intensidad de voxel han demostrado ser criterios de similitud de imágenes robustos, y, entre ellas, la Información Mutua (IM) es siempre la primera elegida en registros multimodales. Sin embargo, uno de los principales problemas de la IM es la ausencia de información espacial y la asunción de que las relaciones estadísticas entre las imágenes son homogéneas a lo largo de su domino completo. La hipótesis de esta tesis es que la incorporación de información espacial de órganos al proceso de registro puede mejorar la robustez y calidad del mismo, beneficiándose de la disponibilidad de las segmentaciones clínicas. En este trabajo, se propone y valida un esquema de registro multimodal no rígido 3D usando una nueva métrica llamada Información Mutua Centrada en el Órgano (Organ-Focused Mutual Information metric (OF-MI)) y se compara con la formulación clásica de la Información Mutua. Esto permite mejorar los resultados del registro en áreas problemáticas incorporando información regional al criterio de similitud, beneficiándose de la disponibilidad real de segmentaciones en protocolos estándares clínicos, y permitiendo que la dependencia estadística entre las dos modalidades de imagen difiera entre órganos o regiones. El método propuesto se ha aplicado al registro de TC y RM con contraste Gd–EOB–DTPA así como al registro de imágenes de TC y MR para planificación de radioterapia intraoperatoria rectal. Adicionalmente, se ha desarrollado un algoritmo de apoyo de segmentación 3D basado en Level-Sets para la incorporación de la información de órgano en el registro. El algoritmo de segmentación se ha diseñado específicamente para la estimación volumétrica de hígado sano funcional y ha demostrado un buen funcionamiento en un conjunto de imágenes de TC abdominales. Los resultados muestran una mejora estadísticamente significativa de OF-MI comparada con la Información Mutua clásica en las medidas de calidad de los registros; tanto con datos simulados (p<0.001) como con datos reales en registro hepático de TC y RM con contraste Gd– EOB–DTPA y en registro para planificación de radioterapia rectal usando OF-MI multi-órgano (p<0.05). Adicionalmente, OF-MI presenta resultados más estables con menor dispersión que la Información Mutua y un comportamiento más robusto con respecto a cambios en la relación señal-ruido y a la variación de parámetros. La métrica OF-MI propuesta en esta tesis presenta siempre igual o mayor precisión que la clásica Información Mutua y consecuentemente puede ser una muy buena alternativa en aplicaciones donde la robustez del método y la facilidad en la elección de parámetros sean particularmente importantes. Abstract Pre-operative planning has become an essential task in complex surgeries and therapies, especially for those affecting soft tissue. One example where soft tissue preoperative planning is of high interest is liver surgery. It involves the accurate detection and identification of individual liver lesions and vessels as well as the proper functional liver segmentation and volume estimation. This process is very important because it determines whether the patient is a suitable candidate for surgical therapy and the type of procedure. Soft tissue radiation therapy is a second example where planning is required for both conventional external and intraoperative radiotherapy. It involves the segmentation of the tumor target and vulnerable organs and the estimation of the planned dose. Functional liver segmentations and volume estimations for surgery planning are commonly estimated from computed tomography (CT) images. Similarly, in radiation therapy planning, targets to be irradiated and healthy and vulnerable tissues to be protected from irradiation are commonly delineated on CT scans. However, developments in magnetic resonance imaging (MRI) technology are progressively offering advantages. For instance, the hepatic metastasis detection rate has been found to be significantly higher in Gd–EOB–DTPAenhanced MRI than in CT. Therefore, recent studies highlight the importance of combining the information from CT and MRI to achieve the highest level of accuracy in radiotherapy and to facilitate accurate liver lesion description. In order to improve those two soft tissue pre operative planning scenarios, an accurate nonrigid image registration algorithm is clearly required. However, the vast majority of commercial systems only provide rigid registration. Voxel intensity measures have been shown to be robust measures of image similarity, and among them, Mutual Information (MI) is always the first candidate in multimodal registrations. However, one of the main drawbacks of Mutual Information is the absence of spatial information and the assumption that statistical relationships between images are the same over the whole domain of the image. The hypothesis of the present thesis is that incorporating spatial organ information into the registration process may improve the registration robustness and quality, taking advantage of the clinical segmentations availability. In this work, a multimodal nonrigid 3D registration framework using a new Organ- Focused Mutual Information metric (OF-MI) is proposed, validated and compared to the classical formulation of the Mutual Information (MI). It allows improving registration results in problematic areas by adding regional information into the similitude criterion taking advantage of actual segmentations availability in standard clinical protocols and allowing the statistical dependence between the two modalities differ among organs or regions. The proposed method is applied to CT and T1 weighted delayed Gd–EOB–DTPA-enhanced MRI registration as well as to register CT and MRI images in rectal intraoperative radiotherapy planning. Additionally, a 3D support segmentation algorithm based on Level-Sets has been developed for the incorporation of the organ information into the registration. The segmentation algorithm has been specifically designed for the healthy and functional liver volume estimation demonstrating good performance in a set of abdominal CT studies. Results show a statistical significant improvement of registration quality measures with OF-MI compared to MI with both simulated data (p<0.001) and real data in liver applications registering CT and Gd–EOB–DTPA-enhanced MRI and in registration for rectal radiotherapy planning using multi-organ OF-MI (p<0.05). Additionally, OF-MI presents more stable results with smaller dispersion than MI and a more robust behavior with respect to SNR changes and parameters variation. The proposed OF-MI always presents equal or better accuracy than the classical MI and consequently can be a very convenient alternative within applications where the robustness of the method and the facility to choose the parameters are particularly important.
Resumo:
Abstract The creation of atlases, or digital models where information from different subjects can be combined, is a field of increasing interest in biomedical imaging. When a single image does not contain enough information to appropriately describe the organism under study, it is then necessary to acquire images of several individuals, each of them containing complementary data with respect to the rest of the components in the cohort. This approach allows creating digital prototypes, ranging from anatomical atlases of human patients and organs, obtained for instance from Magnetic Resonance Imaging, to gene expression cartographies of embryo development, typically achieved from Light Microscopy. Within such context, in this PhD Thesis we propose, develop and validate new dedicated image processing methodologies that, based on image registration techniques, bring information from multiple individuals into alignment within a single digital atlas model. We also elaborate a dedicated software visualization platform to explore the resulting wealth of multi-dimensional data and novel analysis algo-rithms to automatically mine the generated resource in search of bio¬logical insights. In particular, this work focuses on gene expression data from developing zebrafish embryos imaged at the cellular resolution level with Two-Photon Laser Scanning Microscopy. Disposing of quantitative measurements relating multiple gene expressions to cell position and their evolution in time is a fundamental prerequisite to understand embryogenesis multi-scale processes. However, the number of gene expressions that can be simultaneously stained in one acquisition is limited due to optical and labeling constraints. These limitations motivate the implementation of atlasing strategies that can recreate a virtual gene expression multiplex. The developed computational tools have been tested in two different scenarios. The first one is the early zebrafish embryogenesis where the resulting atlas constitutes a link between the phenotype and the genotype at the cellular level. The second one is the late zebrafish brain where the resulting atlas allows studies relating gene expression to brain regionalization and neurogenesis. The proposed computational frameworks have been adapted to the requirements of both scenarios, such as the integration of partial views of the embryo into a whole embryo model with cellular resolution or the registration of anatom¬ical traits with deformable transformation models non-dependent on any specific labeling. The software implementation of the atlas generation tool (Match-IT) and the visualization platform (Atlas-IT) together with the gene expression atlas resources developed in this Thesis are to be made freely available to the scientific community. Lastly, a novel proof-of-concept experiment integrates for the first time 3D gene expression atlas resources with cell lineages extracted from live embryos, opening up the door to correlate genetic and cellular spatio-temporal dynamics. La creación de atlas, o modelos digitales, donde la información de distintos sujetos puede ser combinada, es un campo de creciente interés en imagen biomédica. Cuando una sola imagen no contiene suficientes datos como para describir apropiadamente el organismo objeto de estudio, se hace necesario adquirir imágenes de varios individuos, cada una de las cuales contiene información complementaria respecto al resto de componentes del grupo. De este modo, es posible crear prototipos digitales, que pueden ir desde atlas anatómicos de órganos y pacientes humanos, adquiridos por ejemplo mediante Resonancia Magnética, hasta cartografías de la expresión genética del desarrollo de embrionario, típicamente adquiridas mediante Microscopía Optica. Dentro de este contexto, en esta Tesis Doctoral se introducen, desarrollan y validan nuevos métodos de procesado de imagen que, basándose en técnicas de registro de imagen, son capaces de alinear imágenes y datos provenientes de múltiples individuos en un solo atlas digital. Además, se ha elaborado una plataforma de visualization específicamente diseñada para explorar la gran cantidad de datos, caracterizados por su multi-dimensionalidad, que resulta de estos métodos. Asimismo, se han propuesto novedosos algoritmos de análisis y minería de datos que permiten inspeccionar automáticamente los atlas generados en busca de conclusiones biológicas significativas. En particular, este trabajo se centra en datos de expresión genética del desarrollo embrionario del pez cebra, adquiridos mediante Microscopía dos fotones con resolución celular. Disponer de medidas cuantitativas que relacionen estas expresiones genéticas con las posiciones celulares y su evolución en el tiempo es un prerrequisito fundamental para comprender los procesos multi-escala característicos de la morfogénesis. Sin embargo, el número de expresiones genéticos que pueden ser simultáneamente etiquetados en una sola adquisición es reducido debido a limitaciones tanto ópticas como del etiquetado. Estas limitaciones requieren la implementación de estrategias de creación de atlas que puedan recrear un multiplexado virtual de expresiones genéticas. Las herramientas computacionales desarrolladas han sido validadas en dos escenarios distintos. El primer escenario es el desarrollo embrionario temprano del pez cebra, donde el atlas resultante permite constituir un vínculo, a nivel celular, entre el fenotipo y el genotipo de este organismo modelo. El segundo escenario corresponde a estadios tardíos del desarrollo del cerebro del pez cebra, donde el atlas resultante permite relacionar expresiones genéticas con la regionalización del cerebro y la formación de neuronas. La plataforma computacional desarrollada ha sido adaptada a los requisitos y retos planteados en ambos escenarios, como la integración, a resolución celular, de vistas parciales dentro de un modelo consistente en un embrión completo, o el alineamiento entre estructuras de referencia anatómica equivalentes, logrado mediante el uso de modelos de transformación deformables que no requieren ningún marcador específico. Está previsto poner a disposición de la comunidad científica tanto la herramienta de generación de atlas (Match-IT), como su plataforma de visualización (Atlas-IT), así como las bases de datos de expresión genética creadas a partir de estas herramientas. Por último, dentro de la presente Tesis Doctoral, se ha incluido una prueba conceptual innovadora que permite integrar los mencionados atlas de expresión genética tridimensionales dentro del linaje celular extraído de una adquisición in vivo de un embrión. Esta prueba conceptual abre la puerta a la posibilidad de correlar, por primera vez, las dinámicas espacio-temporales de genes y células.
Resumo:
The arrival of European master masons to Burgos and Toledo during the mid-fifteenth century was essential for the promotion of the late Gothic ribbed vault design techniques in Spain. The Antigua Chapel in Seville Cathedral, designed by the Spanish master mason Simón de Colonia on 1497, provides an outstanding case study on this subject. This vault is characterized by the interlacing of the ribs near the springing, reflecting the influence of German ribbed vault designs. This paper analyses the relationship between German ribbed vaults and their design methods with those of Spanish ribbed vaults; with particular attention to the presence of ribs that cut through one another above the springing, materialized in the work of Simón de Colonia. This characteristic is reflected in some manuscripts in the German area, like the Wiener Sammlungen (15th-16th centuries) and the Codex Miniatus 3 (ca. 1560-1570), but no Spanish documents of the same period make reference to it.
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In this paper we investigate whether conventional text categorization methods may suffice to infer different verbal intelligence levels. This research goal relies on the hypothesis that the vocabulary that speakers make use of reflects their verbal intelligence levels. Automatic verbal intelligence estimation of users in a spoken language dialog system may be useful when defining an optimal dialog strategy by improving its adaptation capabilities. The work is based on a corpus containing descriptions (i.e. monologs) of a short film by test persons yielding different educational backgrounds and the verbal intelligence scores of the speakers. First, a one-way analysis of variance was performed to compare the monologs with the film transcription and to demonstrate that there are differences in the vocabulary used by the test persons yielding different verbal intelligence levels. Then, for the classification task, the monologs were represented as feature vectors using the classical TF–IDF weighting scheme. The Naive Bayes, k-nearest neighbors and Rocchio classifiers were tested. In this paper we describe and compare these classification approaches, define the optimal classification parameters and discuss the classification results obtained.
Resumo:
In tunnel construction, as in every engineering work, it is usual the decision making, with incomplete data. Nevertheless, consciously or not, the builder weighs the risks (even if this is done subjectively) so that he can offer a cost. The objective of this paper is to recall the existence of a methodology to treat the uncertainties in the data so that it is possible to see their effect on the output of the computational model used and then to estimate the failure probability or the safety margin of a structure. In this scheme it is possible to include the subjective knowledge on the statistical properties of the random variables and, using a numerical model consistent with the degree of complexity appropiate to the problem at hand, to make rationally based decisions. As will be shown with the method it is possible to quantify the relative importance of the random variables and, in addition, it can be used, under certain conditions, to solve the inverse problem. It is then a method very well suited both to the project and to the control phases of tunnel construction.
Resumo:
Computational fluid dynamic (CFD) methods are used in this paper to predict the power production from entire wind farms in complex terrain and to shed some light into the wake flow patterns. Two full three-dimensional Navier–Stokes solvers for incompressible fluid flow, employing k − ϵ and k − ω turbulence closures, are used. The wind turbines are modeled as momentum absorbers by means of their thrust coefficient through the actuator disk approach. Alternative methods for estimating the reference wind speed in the calculation of the thrust are tested. The work presented in this paper is part of the work being undertaken within the UpWind Integrated Project that aims to develop the design tools for next generation of large wind turbines. In this part of UpWind, the performance of wind farm and wake models is being examined in complex terrain environment where there are few pre-existing relevant measurements. The focus of the work being carried out is to evaluate the performance of CFD models in large wind farm applications in complex terrain and to examine the development of the wakes in a complex terrain environment.
Resumo:
Connectivity analysis on diffusion MRI data of the whole-brain suffers from distortions caused by the standard echo-planar imaging acquisition strategies. These images show characteristic geometrical deformations and signal destruction that are an important drawback limiting the success of tractography algorithms. Several retrospective correction techniques are readily available. In this work, we use a digital phantom designed for the evaluation of connectivity pipelines. We subject the phantom to a “theoretically correct” and plausible deformation that resembles the artifact under investigation. We correct data back, with three standard methodologies (namely fieldmap-based, reversed encoding-based, and registration- based). Finally, we rank the methods based on their geometrical accuracy, the dropout compensation, and their impact on the resulting connectivity matrices.
Resumo:
Penguin colonies represent some of the most concentrated sources of ammonia emissions to the atmosphere in the world. The ammonia emitted into the atmosphere can have a large influence on the nitrogen cycling of ecosystems near the colonies. However, despite the ecological importance of the emissions, no measurements of ammonia emissions from penguin colonies have been made. The objective of this work was to determine the ammonia emission rate of a penguin colony using inverse-dispersion modelling and gradient methods. We measured meteorological variables and mean atmospheric concentrations of ammonia at seven locations near a colony of Adélie penguins in Antarctica to provide input data for inverse-dispersion modelling. Three different atmospheric dispersion models (ADMS, LADD and a Lagrangian stochastic model) were used to provide a robust emission estimate. The Lagrangian stochastic model was applied both in ‘forwards’ and ‘backwards’ mode to compare the difference between the two approaches. In addition, the aerodynamic gradient method was applied using vertical profiles of mean ammonia concentrations measured near the centre of the colony. The emission estimates derived from the simulations of the three dispersion models and the aerodynamic gradient method agreed quite well, giving a mean emission of 1.1 g ammonia per breeding pair per day (95% confidence interval: 0.4–2.5 g ammonia per breeding pair per day). This emission rate represents a volatilisation of 1.9% of the estimated nitrogen excretion of the penguins, which agrees well with that estimated from a temperature-dependent bioenergetics model. We found that, in this study, the Lagrangian stochastic model seemed to give more reliable emission estimates in ‘forwards’ mode than in ‘backwards’ mode due to the assumptions made.
Resumo:
The increasing number of works related to the surface texture characterization based on 3D information, makes convenient rethinking traditional methods based on two-dimensional measurements from profiles. This work compares results between measurements obtained using two and three-dimensional methods. It uses three kinds of data sources: reference surfaces, randomly generated surfaces and measured. Preliminary results are presented. These results must be completed trying to cover a wider number of possibilities according to the manufacturing process and the measurement instrumentation since results can vary quite significantly between them.