995 resultados para Spatial Integration
Resumo:
Previous work has shown that human vision performs spatial integration of luminance contrast energy, where signals are squared and summed (with internal noise) over area at detection threshold. We tested that model here in an experiment using arrays of micro-pattern textures that varied in overall stimulus area and sparseness of their target elements, where the contrast of each element was normalised for sensitivity across the visual field. We found a power-law improvement in performance with stimulus area, and a decrease in sensitivity with sparseness. While the contrast integrator model performed well when target elements constituted 50–100% of the target area (replicating previous results), observers outperformed the model when texture elements were sparser than this. This result required the inclusion of further templates in our model, selective for grids of various regular texture densities. By assuming a MAX operation across these noisy mechanisms the model also accounted for the increase in the slope of the psychometric function that occurred as texture density decreased. Thus, for the first time, mechanisms that are selective for texture density have been revealed at contrast detection threshold. We suggest that these mechanisms have a role to play in the perception of visual textures.
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In this thesis, research for tsunami remote sensing using the Global Navigation Satellite System-Reflectometry (GNSS-R) delay-Doppler maps (DDMs) is presented. Firstly, a process for simulating GNSS-R DDMs of a tsunami-dominated sea sur- face is described. In this method, the bistatic scattering Zavorotny-Voronovich (Z-V) model, the sea surface mean square slope model of Cox and Munk, and the tsunami- induced wind perturbation model are employed. The feasibility of the Cox and Munk model under a tsunami scenario is examined by comparing the Cox and Munk model- based scattering coefficient with the Jason-1 measurement. A good consistency be- tween these two results is obtained with a correlation coefficient of 0.93. After con- firming the applicability of the Cox and Munk model for a tsunami-dominated sea, this work provides the simulations of the scattering coefficient distribution and the corresponding DDMs of a fixed region of interest before and during the tsunami. Fur- thermore, by subtracting the simulation results that are free of tsunami from those with presence of tsunami, the tsunami-induced variations in scattering coefficients and DDMs can be clearly observed. Secondly, a scheme to detect tsunamis and estimate tsunami parameters from such tsunami-dominant sea surface DDMs is developed. As a first step, a procedure to de- termine tsunami-induced sea surface height anomalies (SSHAs) from DDMs is demon- strated and a tsunami detection precept is proposed. Subsequently, the tsunami parameters (wave amplitude, direction and speed of propagation, wavelength, and the tsunami source location) are estimated based upon the detected tsunami-induced SSHAs. In application, the sea surface scattering coefficients are unambiguously re- trieved by employing the spatial integration approach (SIA) and the dual-antenna technique. Next, the effective wind speed distribution can be restored from the scat- tering coefficients. Assuming all DDMs are of a tsunami-dominated sea surface, the tsunami-induced SSHAs can be derived with the knowledge of background wind speed distribution. In addition, the SSHA distribution resulting from the tsunami-free DDM (which is supposed to be zero) is considered as an error map introduced during the overall retrieving stage and is utilized to mitigate such errors from influencing sub- sequent SSHA results. In particular, a tsunami detection procedure is conducted to judge the SSHAs to be truly tsunami-induced or not through a fitting process, which makes it possible to decrease the false alarm. After this step, tsunami parameter estimation is proceeded based upon the fitted results in the former tsunami detec- tion procedure. Moreover, an additional method is proposed for estimating tsunami propagation velocity and is believed to be more desirable in real-world scenarios. The above-mentioned tsunami-dominated sea surface DDM simulation, tsunami detection precept and parameter estimation have been tested with simulated data based on the 2004 Sumatra-Andaman tsunami event.
Resumo:
The analysis of urban conurbations demands the understanding regarding the difference between urban territorial continuity and spatial continuity. While the spatial continuity is understood due to its interrelations and established fluxes, in other words, through the spatial integration, the territorial continuity is related to the urban tissue. Therefore, the spatial continuity can manifest in a simultaneous way or associated to the territorial discontinuity. From this perspective, the main objective of this research consists on identifying and dimensioning the spatial interactions that are driven to a urban conurbation process between the municipalities of Araguari and Uberlândia/MG, besides the not continuity of the territorial urban area. The intensity of these interactions was identified from the displacements by the dwellers from both municipalities in search of job occupations, education and health assistance. So it would be able to reach the proposed objectives we used several methodological procedures, such as a bibliographic and documental researches. In order to identify the education and work fluxes we analyzed the micro data from the Demographic Census 2010. For the educational sector it was also accomplished a research, in Araguari, the place of residence of students enrolled at Instituto Master de Ensino Presidente Antônio Carlos (IMEPAC) and, in Uberlândia, the place of residence of students enrolled at Universidade Federal de Uberlândia (UFU). The identification of health fluxes was done through a research, in Uberlândia, of the inpatients' origin at Hospital de Clínicas de Uberlândia of the Universidade Federal de Uberlândia (HCU/UFU) and, in Araguari, of the origin of patients that are attended at the Pronto-Socorro Municipal. Semi structured interviews were also accomplished with different social actors. Another important step was the use of questionnaires with the inter-municipal public transportation users at their boarding place in Araguari and Uberlândia. This paper was organized in five chapters, while in the first one we accomplished a theoretical discussion over the concept of urban conurbation, in order to presenting the identification and classification criteria and the urban conurbation of non metropolitan criteria. The second chapter analyses the differentiation process between Araguari and Uberlândia, which is a result of the distinct territorial formation of the municipalities. The third chapter analyses the intensity and degree of the spatial interactions between the two municipalities, having as a focus the established fluxes in the work sector. The fourth chapter, on the other hand, focuses on the education and health sectors, while the last chapter accomplishes a discussion to investigate if the analyzed fluxes in the previous chapters make it able to identify if the spatial interactions established between Araguari and Uberlândia are measured through complementarities or dependence. As a result it was possible to identify that, due to the expressiveness of the established fluxes between the two municipalities, beyond the further ones of Triângulo Mineiro and Alto Paranaíba in the three selected sectors, there is a configuration of a discontinuous urban conurbation process. It was also possible to conclude that, despite the fluxes between Araguari and Uberlândia being more representative than the other way around there's a coexistence dependence relationship and complementarity between the two municipalities.
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This study intends to enhance the existing knowledge concerning the patterns of the uses of space for low cost housing in Parnamirim, Rio Grande do Norte, Brazil, by way of comparative morphological studies in spatial arrangements and articulations regarding three distinct, however inter-related, sets of social housing: (1) a development comprising 21 self-built houses erected on public routes and illegal plots within a tract of land originally designed to be an industrial development: (2) architect-designed houses built by the public authority in order to accommodate the previous 21 (plus a few additions) families occupying the self-built dwellings, and (3) modifications performed by dwellers on a total of those 24 houses built by the public authority after an occupation period of one year. The predominant uses of each room within the self-built and modified houses were represented in ground plan, based on empirical observation, surveys with dwellers and the use of analytical procedures of morphologic analysis of nature predominantly geometric (specific) and topology (space syntax analysis). A scale of priorities was identified in relation to the uses of each room, its geometrical arrangement (adjacency, front/back relations etc), and underlying structures (connectivity, depth and spatial integration) in order to establish congruencies and non-congruencies between a social-cultural order embedded in the self-built domestic space and the design logic contained in the houses offered by official agencies. The comparative analysis points towards the convivial existence of two tendencies: one that seems to reinforce a design logic inasmuch as the additions and modifications performed by the dwellers do not alter but even emphasize the original configuration of the designed houses, and another one in which those patterns are subverted in accordance with a logic which, to a lesser or greater degree, coincides with that of the self-built dwellings
Resumo:
This study intends to enhance the existing knowledge concerning the patterns of the uses of space for low cost housing in Parnamirim, Rio Grande do Norte, Brazil, by way of comparative morphological studies in spatial arrangements and articulations regarding three distinct, however inter-related, sets of social housing: (1) a development comprising 21 self-built houses erected on public routes and illegal plots within a tract of land originally designed to be an industrial development: (2) architect-designed houses built by the public authority in order to accommodate the previous 21 (plus a few additions) families occupying the self-built dwellings, and (3) modifications performed by dwellers on a total of those 24 houses built by the public authority after an occupation period of one year. The predominant uses of each room within the self-built and modified houses were represented in ground plan, based on empirical observation, surveys with dwellers and the use of analytical procedures of morphologic analysis of nature predominantly geometric (specific) and topology (space syntax analysis). A scale of priorities was identified in relation to the uses of each room, its geometrical arrangement (adjacency, front/back relations etc), and underlying structures (connectivity, depth and spatial integration) in order to establish congruencies and non-congruencies between a social-cultural order embedded in the self-built domestic space and the design logic contained in the houses offered by official agencies. The comparative analysis points towards the convivial existence of two tendencies: one that seems to reinforce a design logic inasmuch as the additions and modifications performed by the dwellers do not alter but even emphasize the original configuration of the designed houses, and another one in which those patterns are subverted in accordance with a logic which, to a lesser or greater degree, coincides with that of the self-built dwellings
Resumo:
En el planteamiento de la presente disertación, se tienen en consideración las premisas sobre los orígenes de la ciudad, su influencia industrial y su resolución a través de la Teoría de la Lógica Social del Espacio como herramienta de trabajo para los análisis sobre los planes urbanos propuestos para el municipio a estudio, su historia y para la elaboración de propuestas de interacción futuras. Inicialmente, la propuesta surge de la importancia de las vías de comunicación, como elemento creador urbano, es decir, de una determinada infraestructura, la calle-carretera como el “eje” de consolidación de la ciudad, donde se realizan la mayoría de recorridos o flujos en este caso, ejemplificado en la villa de Porriño. El urbanismo pos-moderno, hasta finales de 1970 e inicios de 1980, no abordaba una articulación entre social y técnica, una ciencia de lucha de clases. En este contexto, en 1984, Bill Hillier y Julienne Hanson escriben “La Lógica Social del Espacio” donde argumentan que los movimientos o flujos obedecen a una lógica racional, según la cual, cualquier desplazamiento es llevado a cabo por el menor recorrido y, por tanto, el urbanismo influye en esos flujos. La configuración urbana genera condiciones de accesibilidad y da origen a una diferenciación espacial jerarquizada con conceptos como la conectividad, integración y segregación en un espacio influenciado y construido por la dinámica social. De este modo, la Teoría de la Sintaxis Espacial describe la configuración del trazado urbano y las relaciones entre el espacio público y privado a través de medidas cuantitativas, las cuales permiten entender aspectos importantes del sistema urbano como la accesibilidad y la distribución y usos del suelo consolidado. Por tanto, en la teoría existe una correlación establecida entre las propiedades de los elementos presentados, espacio y sociedad, de modo que cada elemento incumbe al otro y no existiría sin su presencia, siendo fundamental para la definición de la forma. Esta herramienta, Space Syntax, busca la integración del espacio en la ciudad, mediante un análisis y una evaluación a diversas escalas en la red urbana, con una correcta distribución de los espacios, sus usos y las vías de transporte o comunicación necesarios para llegar a los diferentes lugares de la ciudad. La realización de la investigación se centrará en el análisis de la infraestructura viaria en el municipio de Porriño y sus regiones colindantes a lo largo del período histórico analizado, centrándose en tres momentos históricos, 1956, 1986 y la actualidad 2015, debido a los vuelos fotogramétricos de dichas etapas. Así, se obtendrán las respectivas mediciones correspondientes a través del programa informático Depthmap, las cuales se contrarrestarán y compararán entre sí en cada etapa analizada y entre los propios años examinados, para lograr obtener las consideraciones establecidas a lo largo del estudio en cuanto a la influencia comunicativa de los flujos de interacción social en el entorno urbano definido y la respectiva lucha de los sectores industriales y residenciales. En conclusión, se pretende la justificación del origen de la ciudad a través de la comparación sus vías, las cuales fueron fomentadas por el comercio e industria para su creación, dotando así a la industria del dominio del espacio para satisfacer sus necesidades, creando y ampliando su área de intervención, la cual puede ser analizada y tratada no sólo independientemente, sino en el conjunto urbano en el que se sitúa, Porriño.
Resumo:
Male and female Wistar rats were treated postnatally (PND 5-16) with BSO (l-buthionine-(S,R)-sulfoximine) to provide a rat model of schizophrenia based on transient glutathione deficit. In the watermaze, BSO-treated male rats perform very efficiently in conditions where a diversity of visual information is continuously available during orientation trajectories [1]. Our hypothesis is that the treatment impairs proactive strategies anticipating future sensory information, while supporting a tight visual adjustment on memorized snapshots, i.e. compensatory reactive strategies. To test this hypothesis, BSO rats' performance was assessed in two conditions using an 8-arm radial maze task: a semi-transparent maze with no available view on the environment from maze centre [2], and a modified 2-parallel maze known to induce a neglect of the parallel pair in normal rats [3-5]. Male rats, but not females, were affected by the BSO treatment. In the semi-transparent maze, BSO males expressed a higher error rate, especially in completing the maze after an interruption. In the 2-parallel maze shape, BSO males, unlike controls, expressed no neglect of the parallel arms. This second result was in accord with a reactive strategy using accurate memory images of the contextual environment instead of a representation based on integrating relative directions. These results are coherent with a treatment-induced deficit in proactive decision strategy based on multimodal cognitive maps, compensated by accurate reactive adaptations based on the memory of local configurations. Control females did not express an efficient proactive capacity in the semi-transparent maze, neither did they show the significant neglect of the parallel arms, which might have masked the BSO induced effect. Their reduced sensitivity to BSO treatment is discussed with regard to a sex biased basal cognitive style.
Resumo:
The aim of the present study was to determine whether and how rats can use local olfactory cues for spatial orientation. Rats were trained in an eight-arm radial maze under different conditions as defined by the presence or absence of supplementary olfactory cues marking each arm, the availability of distant visuospatial information, and the illumination of the maze (light or darkness). The different visual conditions were designed to dissociate among the effects of light per se and those of visuospatial cues, on the use of olfactory cues for accurate arm choice. Different procedures with modifications of the arrangement of olfactory cues were used to determine if rats formed a representation of the spatial configuration of the olfactory cues and if they could rely on such a representation for accurate arm choice in the radial maze. The present study demonstrated that the use of olfactory cues to direct arm choice in the radial arm maze was critically dependent on the illumination conditions and implied two different modes of processing of olfactory information according to the presence or the absence of light. Olfactory cues were used in an explicit manner and enabled accurate arm choice only in the absence of light. Rats, however, had an implicit memory of the location of the olfactory cues and formed a representation of the spatial position of these cues, whatever the lighting conditions. They did not memorize the spatial configuration of the olfactory cues per se but needed these cues to be linked to the external spatial frame of reference.
Resumo:
Global positioning systems (GPS) offer a cost-effective and efficient method to input and update transportation data. The spatial location of objects provided by GPS is easily integrated into geographic information systems (GIS). The storage, manipulation, and analysis of spatial data are also relatively simple in a GIS. However, many data storage and reporting methods at transportation agencies rely on linear referencing methods (LRMs); consequently, GPS data must be able to link with linear referencing. Unfortunately, the two systems are fundamentally incompatible in the way data are collected, integrated, and manipulated. In order for the spatial data collected using GPS to be integrated into a linear referencing system or shared among LRMs, a number of issues need to be addressed. This report documents and evaluates several of those issues and offers recommendations. In order to evaluate the issues associated with integrating GPS data with a LRM, a pilot study was created. To perform the pilot study, point features, a linear datum, and a spatial representation of a LRM were created for six test roadway segments that were located within the boundaries of the pilot study conducted by the Iowa Department of Transportation linear referencing system project team. Various issues in integrating point features with a LRM or between LRMs are discussed and recommendations provided. The accuracy of the GPS is discussed, including issues such as point features mapping to the wrong segment. Another topic is the loss of spatial information that occurs when a three-dimensional or two-dimensional spatial point feature is converted to a one-dimensional representation on a LRM. Recommendations such as storing point features as spatial objects if necessary or preserving information such as coordinates and elevation are suggested. The lack of spatial accuracy characteristic of most cartography, on which LRM are often based, is another topic discussed. The associated issues include linear and horizontal offset error. The final topic discussed is some of the issues in transferring point feature data between LRMs.
Resumo:
An exemination of a series of indicators of economic integration in the western hemisphere (Canada-USA-Latin America) indicates that it is proceeding under the influence of formal trade agreements and informal forces including technological change, multinational firm rationalization and location strategies, etc.
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The objective of this work was to evaluate extreme water table depths in a watershed, using methods for geographical spatial data analysis. Groundwater spatio-temporal dynamics was evaluated in an outcrop of the Guarani Aquifer System. Water table depths were estimated from monitoring of water levels in 23 piezometers and time series modeling available from April 2004 to April 2011. For generation of spatial scenarios, geostatistical techniques were used, which incorporated into the prediction ancillary information related to the geomorphological patterns of the watershed, using a digital elevation model. This procedure improved estimates, due to the high correlation between water levels and elevation, and aggregated physical sense to predictions. The scenarios showed differences regarding the extreme levels - too deep or too shallow ones - and can subsidize water planning, efficient water use, and sustainable water management in the watershed.
Resumo:
Simulation techniques are almost indispensable in the analysis of complex systems. Materials- and related information flow processes in logistics often possess such complexity. Further problem arise as the processes change over time and pose a Big Data problem as well. To cope with these issues adaptive simulations are more and more frequently used. This paper presents a few relevant advanced simulation models and intro-duces a novel model structure, which unifies modelling of geometrical relations and time processes. This way the process structure and their geometric relations can be handled in a well understandable and transparent way. Capabilities and applicability of the model is also presented via a demonstrational example.