997 resultados para spatial transformation
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Hippocampal slices are used to show that, as a temporal input pattern of activity flows through a neuronal layer, a temporal-to-spatial transformation takes place. That is, neurons can respond selectively to the first or second of a pair of input pulses, thus transforming different temporal patterns of activity into the activity of different neurons. This is demonstrated using associative long-term potentiation of polysynaptic CA1 responses as an activity-dependent marker: by depolarizing a postsynaptic CA1 neuron exclusively with the first or second of a pair of pulses from the dentate gyrus, it is possible to “tag” different subpopulations of CA3 neurons. This technique allows sampling of a population of neurons without recording simultaneously from multiple neurons. Furthermore, it reflects a biologically plausible mechanism by which single neurons may develop selective responses to time-varying stimuli and permits the induction of context-sensitive synaptic plasticity. These experimental results support the view that networks of neurons are intrinsically able to process temporal information and that it is not necessary to invoke the existence of internal clocks or delay lines for temporal processing on the time scale of tens to hundreds of milliseconds.
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We present the first spatial scanning system using wavelength-spatial transformation of chromatic dispersion device. Optical probe used in fiber optic interferometer for surface measurement is demonstrated by using diffraction grating and wavelength scanning technique.
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Pectus excavatum is the most common congenital deformity of the anterior thoracic wall. The surgical correction of such deformity, using Nuss procedure, consists in the placement of a personalized convex prosthesis into sub-sternal position to correct the deformity. The aim of this work is the CT-scan substitution by ultrasound imaging for the pre-operative diagnosis and pre-modeling of the prosthesis, in order to avoid patient radiation exposure. To accomplish this, ultrasound images are acquired along an axial plane, followed by a rigid registration method to obtain the spatial transformation between subsequent images. These images are overlapped to reconstruct an axial plane equivalent to a CT-slice. A phantom was used to conduct preliminary experiments and the achieved results were compared with the corresponding CT-data, showing that the proposed methodology can be capable to create a valid approximation of the anterior thoracic wall, which can be used to model/bend the prosthesis
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By the end of the 21st Century, economy globalization trends to show a velocity process through which market being expanded characterized by an intense going on of the internationalization of finance, after that marginalizing the periphery of the social spaces. It is clear to see that this process occurred in those less developed countries happens in an accentuated way just because income distribution that is so regressive and also because the insufficient enclosing of the social programs, we find this situation in a big part of Brazilian cities. The marginalizing social economical process observed in Natal, a city located in the east coast part of Northeast region in Brazil and that owns a population upper to 778 thousand in habitants is nearly linked to the extension of goods and services commerce. The installation of new urban activities in the city pointed out tourist activity as the greater impulsive thing in the phenomenon promotion, most of them aiming to promote Natal to the national and international scenery. It privilege strongly in the South zone with economical implementations such as shopping s centers, supermarkets, and home buildings condominiums leading to a loss of functionality of some traditional district located in central areas of the city. Notwithstanding, some spaces, for instance Alecrim district officially created in 1911, has notably resisted to the expansion of the urban process pointed out in Natal in the last years. So that this put Alecrim District as a district with originally characteristics reaffirmed along the historical process form old times. The predominance of some residential characteristics such as the incidence of some villages and a concentration of a big and confuse popular commerce distributed along streets puts Alecrim District as a resistant space in Natal. The same way analyze Alecrim District under the prism of Historic Geography because we understand this way it accomplishes a fundamental role in the theoretical methodological development of our work, just when we analyze the time as a variant in our object of study. It is still inside this theoretical field that we carry out a brief reviewing about quarter/district definition, under the optic from several registered and scientific resources taken into account along this work, because we understand that it was necessary to think this important spatial unit especially to know exactly what we are referring to as a district and so we can reaffirm Alecrim as an important and traditional district to Natal and it has been resisting to spatial transformation verified in the last years in Natal city. To give support to our reflection we used methodological tools related to inhabitants lifestyles knowledge and also the study of Alecrim District as a space that promote a certain centrality in Natal as some indicators to keep original characteristics in the district in Natal
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Pós-graduação em Geografia - IGCE
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Geografia - FCT
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Este artículo pretende exponer la influencia que las nuevas estrategias de organización territorial para la campaña bonaerense, materializadas durante la primera mitad del siglo XIX, pudieron ejercer sobre la estructura urbana y social de los pueblos de la región. Partimos del supuesto, desarrollado en otros trabajos, de que dichas estrategias definieron, en parte, la transformación espacial del territorio a partir de tres premisas: la consolidación de los poblados existentes, la fundación de nuevos poblados y el desarrollo de la colonización ejidal (1). Para poder examinar en profundidad dichas estrategias tomamos como base el análisis del espacio urbano de Chascomús y sus alrededores considerando dos momentos de su conformación: 1826 y 1855. Estas fechas se corresponden con la existencia de documentos que representan espacialmente el lugar: los planos de Saubidet de 1826 y el plano de Arrufó de 1855. A partir de estos documentos intentaremos determinar cuáles son las estrategias oficiales en relación a la organización espacial, cómo se materializa el poblado, qué tipo de entramado social presenta y cuáles son las diferencias que encontramos entre una época y otra, teniendo en consideración que la primera corresponde al inicio de la expansión de la frontera bonaerense y la segunda al auge de la etapa lanera que tiene en Chascomús uno de sus centros.
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Este artículo pretende exponer la influencia que las nuevas estrategias de organización territorial para la campaña bonaerense, materializadas durante la primera mitad del siglo XIX, pudieron ejercer sobre la estructura urbana y social de los pueblos de la región. Partimos del supuesto, desarrollado en otros trabajos, de que dichas estrategias definieron, en parte, la transformación espacial del territorio a partir de tres premisas: la consolidación de los poblados existentes, la fundación de nuevos poblados y el desarrollo de la colonización ejidal (1). Para poder examinar en profundidad dichas estrategias tomamos como base el análisis del espacio urbano de Chascomús y sus alrededores considerando dos momentos de su conformación: 1826 y 1855. Estas fechas se corresponden con la existencia de documentos que representan espacialmente el lugar: los planos de Saubidet de 1826 y el plano de Arrufó de 1855. A partir de estos documentos intentaremos determinar cuáles son las estrategias oficiales en relación a la organización espacial, cómo se materializa el poblado, qué tipo de entramado social presenta y cuáles son las diferencias que encontramos entre una época y otra, teniendo en consideración que la primera corresponde al inicio de la expansión de la frontera bonaerense y la segunda al auge de la etapa lanera que tiene en Chascomús uno de sus centros.
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Este artículo pretende exponer la influencia que las nuevas estrategias de organización territorial para la campaña bonaerense, materializadas durante la primera mitad del siglo XIX, pudieron ejercer sobre la estructura urbana y social de los pueblos de la región. Partimos del supuesto, desarrollado en otros trabajos, de que dichas estrategias definieron, en parte, la transformación espacial del territorio a partir de tres premisas: la consolidación de los poblados existentes, la fundación de nuevos poblados y el desarrollo de la colonización ejidal (1). Para poder examinar en profundidad dichas estrategias tomamos como base el análisis del espacio urbano de Chascomús y sus alrededores considerando dos momentos de su conformación: 1826 y 1855. Estas fechas se corresponden con la existencia de documentos que representan espacialmente el lugar: los planos de Saubidet de 1826 y el plano de Arrufó de 1855. A partir de estos documentos intentaremos determinar cuáles son las estrategias oficiales en relación a la organización espacial, cómo se materializa el poblado, qué tipo de entramado social presenta y cuáles son las diferencias que encontramos entre una época y otra, teniendo en consideración que la primera corresponde al inicio de la expansión de la frontera bonaerense y la segunda al auge de la etapa lanera que tiene en Chascomús uno de sus centros.
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Purpose: Accurate delineation of the rectum is of high importance in off-line adaptive radiation therapy since it is a major dose-limiting organ in prostate cancer radiotherapy. The intensity-based deformable image registration (DIR) methods cannot create a correct spatial transformation if there is no correspondence between the template and the target images. The variation of rectal filling, gas, or feces, creates a noncorrespondence in image intensities that becomes a great obstacle for intensity-based DIR. Methods: In this study the authors have designed and implemented a semiautomatic method to create a rectum mask in pelvic computed tomography (CT) images. The method, that includes a DIR based on the demons algorithm, has been tested in 13 prostate cancer cases, each comprising of two CT scans, for a total of 26 CT scans. Results: The use of the manual segmentation in the planning image and the proposed rectum mask method (RMM) method in the daily image leads to an improvement in the DIR performance in pelvic CT images, obtaining a mean value of overlap volume index = 0.89, close to the values obtained using the manual segmentations in both images. Conclusions: The application of the RMM method in the daily image and the manual segmentations in the planning image during prostate cancer treatments increases the performance of the registration in presence of rectal fillings, obtaining very good agreement with a physician's manual contours.
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Purpose: Accurate delineation of the rectum is of high importance in off-line adaptive radiation therapy since it is a major dose-limiting organ in prostate cancer radiotherapy. The intensity-based deformable image registration (DIR) methods cannot create a correct spatial transformation if there is no correspondence between the template and the target images. The variation of rectal filling, gas, or feces, creates a noncorrespondence in image intensities that becomes a great obstacle for intensity-based DIR. Methods: In this study the authors have designed and implemented a semiautomatic method to create a rectum mask in pelvic computed tomography (CT) images. The method, that includes a DIR based on the demons algorithm, has been tested in 13 prostate cancer cases, each comprising of two CT scans, for a total of 26 CT scans. Results: The use of the manual segmentation in the planning image and the proposed rectum mask method (RMM) method in the daily image leads to an improvement in the DIR performance in pelvic CT images, obtaining a mean value of overlap volume index = 0.89, close to the values obtained using the manual segmentations in both images. Conclusions: The application of the RMM method in the daily image and the manual segmentations in the planning image during prostate cancer treatments increases the performance of the registration in presence of rectal fillings, obtaining very good agreement with a physician's manual contours.
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La presente investigación analiza la capacidad del color de cualificar los espacios y propone una clasificación que ordene los diferentes dispositivos que actúan en este proceso. El objetivo de esta tesis es describir estos dispositivos estableciéndolos como parte inequívoca de cualquier proceso desencadenado por la presencia del binomio luz y color. El color ha sido objeto de estudio y experimentación a lo largo de la historia, en todas las artes y las distintas disciplinas relacionadas con la física, la percepción y la interacción. De este modo se realiza una aproximación teórica e histórica al color desde puntos de vista interdisciplinares, para llegar a comprender el modo en el que el color se acaba separando de la forma para pasar a formar parte de la configuración del espacio. Con el propósito de alcanzar este objetivo, se ha realizado un recorrido a través de diferentes teorías y manifestaciones artísticas realizadas en torno al color a lo largo de la Historia, para encontrar las claves de la relación del color con el espacio. Tomando de base este primer acercamiento al tema, se realiza un estudio empírico exhaustivo con modelos físicos con el fin de aislar los dispositivos que intervienen el este proceso en el que el color se pone en relación con el espacio; se analiza su variación a medida que fluctúan las características de los elementos que desencadenan los dispositivos. El objetivo es descubrir un orden, una taxonomía, que permita interpretar cualquier transformación producida por el color en el espacio. Posteriormente, se verifica la validez de esta clasificación estudiando siete espacios modelo en los que el color transfigura el espacio mediante la activación conjunta de varios de los dispositivos analizados. Se ha elegido este grupo de siete espacios debido a que, al tomarlos como suma, sus interiores engloban todos los fenómenos encontrados en el análisis previo. El conjunto de los dispositivos que actúan en cada espacio forma un sistema único e irrepetible que tiene que ver con su transfiguración espacial mediante la luz y el color. Estos sistemas constituyen parte de la génesis propia de cada espacio a través de una secuencia de dispositivos de transformación y configuración espacial que lo hace singular. Los dispositivos clasificados en esta investigación se encuentran en cualquier espacio en el que intervengan la luz y el color, agrupándose secuencialmente en sistemas determinados que cualifican el espacio arquitectónico. ABSTRACT This research analyzes the ability of the colour to qualify the spaces and proposes a classification to arrange the different devices that act in this process. The aim of this thesis is to describe these devices, unequivocally established as part of any process triggered by the presence of light and color pairing. Colour has been the subject of study and experimentation throughout history, in all the arts and disciplines related to physics, perception and interaction. Thus a theoretical and historical approach to the colour is developed from interdisciplinary points of view, in order to understand the way that colour separates from the form and is part of the space configuration. With the purpose of reaching this target, there has been a journey through the artistic movements and theories on colour throughout history, seeking for the key points of its relation with the space. Based on these first intuitions as a starting point, an exhaustive empirical study is made with physical models with the purpose of isolating the devices that participate in this process where colour is related with the space as well as analyzing their variation to the extent that the characteristics of the elements which cause them fluctuate. The objective is to discover an order, a taxonomy that allows to performing any transformation produced by the colour in the space. Afterwards, the validity of this classification is verified by studying seven model spaces in which the colour transfigures the space by the combined activation of several analyzed devices. These seven spaces were chosen due to all the phenomenon set in the previous analysis are included in their interior space. The group of devices that act on each space creates an unrepeatable and unique system that has to do with its spatial transfiguration by means of light and colour. These systems form part of the origin itself of each space through a sequence of devices of spatial transformation and configuration that make this space unique. The devices sorted in this research transform and configure any space in which light and colour participate, sequentially grouping together in determined systems that qualify the architectonic space.