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Laakso, Aarre. "The significance of spatial representation /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p9935455.
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Magnani, Barbara <1982>. "The spatial representation of time." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4724/1/Magnani_Barbara_tesi.pdf.
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Numerosi studi mostrano che gli intervalli temporali sono rappresentati attraverso un codice spaziale che si estende da sinistra verso destra, dove gli intervalli brevi sono rappresentati a sinistra rispetto a quelli lunghi. Inoltre tale disposizione spaziale del tempo può essere influenzata dalla manipolazione dell’attenzione-spaziale. La presente tesi si inserisce nel dibattito attuale sulla relazione tra rappresentazione spaziale del tempo e attenzione-spaziale attraverso l’uso di una tecnica che modula l’attenzione-spaziale, ovvero, l’Adattamento Prismatico (AP).
La prima parte è dedicata ai meccanismi sottostanti tale relazione. Abbiamo mostrato che spostando l’attenzione-spaziale con AP, verso un lato dello spazio, si ottiene una distorsione della rappresentazione di intervalli temporali, in accordo con il lato dello spostamento attenzionale. Questo avviene sia con stimoli visivi, sia con stimoli uditivi, nonostante la modalità uditiva non sia direttamente coinvolta nella procedura visuo-motoria di AP. Questo risultato ci ha suggerito che il codice spaziale utilizzato per rappresentare il tempo, è un meccanismo centrale che viene influenzato ad alti livelli della cognizione spaziale. La tesi prosegue con l’indagine delle aree corticali che mediano l’interazione spazio-tempo, attraverso metodi neuropsicologici, neurofisiologici e di neuroimmagine. In particolare abbiamo evidenziato che, le aree localizzate nell’emisfero destro, sono cruciali per l’elaborazione del tempo, mentre le aree localizzate nell’emisfero sinistro sono cruciali ai fini della procedura di AP e affinché AP abbia effetto sugli intervalli temporali. Infine, la tesi, è dedicata allo studio dei disturbi della rappresentazione spaziale del tempo. I risultati ci indicano che un deficit di attenzione-spaziale, dopo danno emisferico destro, provoca un deficit di rappresentazione spaziale del tempo, che si riflette negativamente sulla vita quotidiana dei pazienti. Particolarmente interessanti sono i risultati ottenuti mediante AP. Un trattamento con AP, efficace nel ridurre il deficit di attenzione-spaziale, riduce anche il deficit di rappresentazione spaziale del tempo, migliorando la qualità di vita dei pazienti.Numerous studies showed that time intervals are represented via a spatial code ascending from left to right, where shorter intervals are represented to the left of longer intervals. There is also evidence that, this temporal-spatial line, can be manipulated by manipulating the spatial-attention direction. The present thesis contributes to the current debate on the relationship between spatial representation of time and spatial-attention by using a technique to modulate spatial-attention, i.e. Prismatic-Adaptation (PA). In a first part we wondered about the behavioral mechanisms of the spatial-attention and time interaction. We showed that a shift of spatial-attention toward a side of space by PA, induces a distortion of the representation of time stimuli according to the side of attentional manipulation. This is true for time stimuli presented in visual modality but also in auditory modality that is not directly involved in the visuo-motor procedure of PA. This results suggested that the spatial code used to represent time, is a very centralized representation that is affected by spatial operations at high levels of spatial cognition. We followed with the investigation of the cortical areas subtending the space-time interaction. With neuropsychological, neurophysiological and neuroimaging methods, we found that areas in the right hemisphere are selectively related to the pure processing of time, while areas in the left hemisphere are selectively related to the success of PA procedure and to the effects of PA on time. Finally, we focused on the study of the pathology of the spatial representation of time. We found that a spatial-attention deficit, following a right hemispheric stroke, induces a deficit in the spatial representation of time that reflects in patients’ daily life. Moreover we found that a PA treatment, effective in reducing the spatial-attention deficit, also reduces the spatial representation of time disorder, improving patients’ quality of life.
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Magnani, Barbara <1982>. "The spatial representation of time." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4724/.
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Numerosi studi mostrano che gli intervalli temporali sono rappresentati attraverso un codice spaziale che si estende da sinistra verso destra, dove gli intervalli brevi sono rappresentati a sinistra rispetto a quelli lunghi. Inoltre tale disposizione spaziale del tempo può essere influenzata dalla manipolazione dell’attenzione-spaziale. La presente tesi si inserisce nel dibattito attuale sulla relazione tra rappresentazione spaziale del tempo e attenzione-spaziale attraverso l’uso di una tecnica che modula l’attenzione-spaziale, ovvero, l’Adattamento Prismatico (AP).
La prima parte è dedicata ai meccanismi sottostanti tale relazione. Abbiamo mostrato che spostando l’attenzione-spaziale con AP, verso un lato dello spazio, si ottiene una distorsione della rappresentazione di intervalli temporali, in accordo con il lato dello spostamento attenzionale. Questo avviene sia con stimoli visivi, sia con stimoli uditivi, nonostante la modalità uditiva non sia direttamente coinvolta nella procedura visuo-motoria di AP. Questo risultato ci ha suggerito che il codice spaziale utilizzato per rappresentare il tempo, è un meccanismo centrale che viene influenzato ad alti livelli della cognizione spaziale. La tesi prosegue con l’indagine delle aree corticali che mediano l’interazione spazio-tempo, attraverso metodi neuropsicologici, neurofisiologici e di neuroimmagine. In particolare abbiamo evidenziato che, le aree localizzate nell’emisfero destro, sono cruciali per l’elaborazione del tempo, mentre le aree localizzate nell’emisfero sinistro sono cruciali ai fini della procedura di AP e affinché AP abbia effetto sugli intervalli temporali. Infine, la tesi, è dedicata allo studio dei disturbi della rappresentazione spaziale del tempo. I risultati ci indicano che un deficit di attenzione-spaziale, dopo danno emisferico destro, provoca un deficit di rappresentazione spaziale del tempo, che si riflette negativamente sulla vita quotidiana dei pazienti. Particolarmente interessanti sono i risultati ottenuti mediante AP. Un trattamento con AP, efficace nel ridurre il deficit di attenzione-spaziale, riduce anche il deficit di rappresentazione spaziale del tempo, migliorando la qualità di vita dei pazienti.Numerous studies showed that time intervals are represented via a spatial code ascending from left to right, where shorter intervals are represented to the left of longer intervals. There is also evidence that, this temporal-spatial line, can be manipulated by manipulating the spatial-attention direction. The present thesis contributes to the current debate on the relationship between spatial representation of time and spatial-attention by using a technique to modulate spatial-attention, i.e. Prismatic-Adaptation (PA). In a first part we wondered about the behavioral mechanisms of the spatial-attention and time interaction. We showed that a shift of spatial-attention toward a side of space by PA, induces a distortion of the representation of time stimuli according to the side of attentional manipulation. This is true for time stimuli presented in visual modality but also in auditory modality that is not directly involved in the visuo-motor procedure of PA. This results suggested that the spatial code used to represent time, is a very centralized representation that is affected by spatial operations at high levels of spatial cognition. We followed with the investigation of the cortical areas subtending the space-time interaction. With neuropsychological, neurophysiological and neuroimaging methods, we found that areas in the right hemisphere are selectively related to the pure processing of time, while areas in the left hemisphere are selectively related to the success of PA procedure and to the effects of PA on time. Finally, we focused on the study of the pathology of the spatial representation of time. We found that a spatial-attention deficit, following a right hemispheric stroke, induces a deficit in the spatial representation of time that reflects in patients’ daily life. Moreover we found that a PA treatment, effective in reducing the spatial-attention deficit, also reduces the spatial representation of time disorder, improving patients’ quality of life.
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Fleming, Piers F. "Processing and representation of spatial descriptions." Thesis, Lancaster University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423900.
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El-Geresy, Baher. "Qualitative representation and reasoning for spatial and spatio-temporal systems." Thesis, University of South Wales, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403330.
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Thrash, Tyler. "Categorical bias in transient and enduring spatial representation." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1302800868.
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Hostetter, Michael. "Analogical representation in temporal, spatial, and mnemonic reasoning." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03242009-040545/.
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Lenc, Karel. "Representation of spatial transformations in deep neural networks." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:87a16dc2-9d77-49c3-8096-cf3416fa6893.
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This thesis addresses the problem of investigating the properties and abilities of a variety of computer vision representations with respect to spatial geometric transformations. Our approach is to employ machine learning methods for finding the behaviour of existing image representations empirically and to apply deep learning to new computer vision tasks where the underlying spatial information is of importance. The results help to further the understanding of modern computer vision representations, such as convolutional neural networks (CNNs) in image classification and object detection and to enable their application to new domains such as local feature detection. Because our theoretical understanding of CNNs remains limited, we investigate two key mathematical properties of representations: equivariance (how transformations of the input image are encoded) and equivalence (how two representations, for example two different parameterizations, layers or architectures share the same visual information). A number of methods to establish these properties empirically are proposed. These methods reveal interesting aspects of their structure, including clarifying at which layers in a CNN geometric invariances are achieved and how various CNN architectures differ. We identify several predictors of geometric and architectural compatibility. Direct applications to structured-output regression are demonstrated as well. Local covariant feature detection has been difficult to approach with machine learning techniques. We propose the first fully general formulation for learning local covariant feature detectors which casts detection as a regression problem, enabling the use of powerful regressors such as deep neural networks. The derived covariance constraint can be used to automatically learn which visual structures provide stable anchors for local feature detection. We support these ideas theoretically, and show that existing detectors can be derived in this framework. Additionally, in cooperation with Imperial College London, we introduce a novel large-scale dataset for evaluation of local detectors and descriptors. It is suitable for training and testing modern local features, together with strictly defined evaluation protocols for descriptors in several tasks such as matching, retrieval and verification. The importance of pixel-wise image geometry for object detection is unknown as the best results used to be obtained with combination of CNNs with cues from image segmentation. We propose a detector which uses constant region proposals and, while it approximates objects poorly, we show that a bounding box regressor using intermediate convolutional features can recover sufficiently accurate bounding boxes, demonstrating that the required geometric information is contained in the CNN itself. Combined with other improvements, we obtain an excellent and fast detector that processes an image only with the CNN.
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Andersson, Elin, and Hanna Bengtsson. "Geovisualisering: En rumslig representation av data." Thesis, Malmö universitet, Fakulteten för teknik och samhälle (TS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-43221.
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Internet of things ger oss möjligheten att kunna identifiera, kontrollera och övervaka objekt över hela världen. För att mängden rådata som strömmar in ska kunna skapa mening och insikter till människan krävs det att den presenteras på rätt sätt. Studien undersöker därför om geovisualisering bättre kan möta människans kognitiva förmåga vid intag och tolkning av information. Geovisualisering innebär att rumslig data kan utforskas på en karta via en interaktiv display och är en länk mellan den mänskliga beslutsprocessen, interaktiva gränssnitt och data [21]. Mer forskning behövs inom området för att undersöka hur geovisualisering kan ta plats i system där stora datamängder behöver presenteras på ett överskådligt sätt och stödja beslutsprocesser. Studien syftar till att jämföra geovisualiseringar med ett befintligt system som tillhandahåller kontinuerlig uppdatering och övervakning av nätverkskameror genom utförande av användbarhetstester och intervjuer. Det som undersökts är om geovisualisering kan ge en ökad förståelse och bättre interaktion i ett utrymme som efterliknar den fysiska världen, samt undersöka potentiella problem för att hitta framtida förbättringar. Resultaten visade att navigering och informationsöverbelastning var återkommande problem under testerna av det befintliga systemet. För geovisualiseringarna visade resultaten det motsatta då de istället underlättade förståelsen för interaktion och information. Vissa problem identifierades dock för de framtagna geovisualiseringarna, som exempelvis dess begränsade interaktion och misstolkningar av objekt. Trots detta visade det sig vara fördelaktigt att placera ut enheter i deras verkliga miljö med hjälp av geovisualisering då det bidrog till en bättre översikt och förståelse av systemets sammanhang.The Internet of Things gives us the ability to identify, control and monitor objects around the world. In order to get meaning and knowledge from the amount of raw data, it needs to be presented in the right way for people to get insights from it. The study therefore examines whether geovisualization can better meet human cognitive ability in interpretation of information. Geovisualization means that spatial data can be explored on a map through an interactive display and is a link between the human decision-making process, interactive interfaces and data [21]. More research is needed in the area to investigate how geovisualization can take place in systems where large amounts of data needs to be presented and how it can support decision-making processes. The study aims to compare geovisualizations with an existing system that provides continuous updating and monitoring of network cameras by performing usability tests and interviews. Geovisualization has been investigated to see if it can contribute an increased understanding and better navigation in a space that mimics the physical world, as well as investigate potential problems to find future improvements. The results proved that navigation and information overload were recurring problems during the tests of the existing system. For the geovisualizations, the results proved the opposite as they instead facilitated the understanding of navigation and information. However, some problems were identified for the developed geovisualizations, such as its limited interaction and misinterpretations of objects. Despite this, it proved to be advantageous to place units in their real environment using geovisualization as it contributed to a better overview and understanding of the system's context.
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Goulette, Jean-Pierre. "Representation des connaissances spatiales pour la conception architecturale. Contribution au raisonnement spatial qualitatif." Toulouse 3, 1997. http://www.theses.fr/1997TOU30202.
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Cette etude debute par un bref historique des recherches menees dans les champs de la cao architecturale et de la modelisation du processus de conception. Ce processus est complexe, les problemes de conception en architecture sont mal structures, et, dans sa demarche de conception, l'architecte met en avant des connaissances particulieres qui lui permettent de mieux definir son probleme : les references architecturales. Parmi ces references, nous nous interessons au savoir relatif a la composition architecturale a travers l'exemple d'un element privilegie, a la fois compose et composant, la baie. Nous procedons a l'analyse des descriptions textuelles d'elements d'architecture constituant la baie dans le vocabulaire de l'architecture. Nous rejoignons ainsi certains travaux menes en semantique formelle de l'espace, travaux qui prennent pour point de depart l'etude de textes decrivant des phenomenes spatiaux. Nous presentons ces travaux qui mettent en evidence le fait que la geometrie classique ne suffit pas pour representer et calculer le discours sur l'espace : il faut aussi prendre en compte des niveaux topologique, fonctionnel et pragmatique. Nous reprenons, en les adaptant a notre propos, les resultats de ces travaux. L'analyse des descriptions textuelles d'elements d'architecture et de leurs compositions nous permet de specifier les caracteristiques d'une geometrie pour la cao en architecture. En nous inspirant des theories axiomatiques de la mereotopologie, nous proposons un ensemble de definitions formelles (en logique des predicats) des elements et des relations constituant un cadre d'enonciation des connaissances relatives a la composition des baies en architecture. Nous disposons ainsi d'un langage formel permettant d'exprimer certaines lois de la composition architecturale et de raisonner sur les proprietes des compositions et de leurs constituants. Une maquette logicielle illustre concretement certains resultats de notre etude.
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Wallace, Desmond D. "The diffusion of representation." Diss., University of Iowa, 2019. https://ir.uiowa.edu/etd/7041.
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An important feature of a democratic society is the notion that the actions and decisions of elected representatives reflect their constituents’ preferences. Existing research shows multiple ways an elected official “represents” the opinions of the public. For example, some elected officials represent their constituents’ preferences absent their personal beliefs and opinions, while other representatives choose to make decisions based on their beliefs absent the views of their constituents. Despite the proliferation in political representation research, one area that has received little attention from scholars is whether the actions of elected officials and their constituents have an influence on how representative elected officials in other jurisdictions are of their constituents. The failure to capture the non-independent features of representation leads to scholars not understanding fully the opinion-policy relationship between politicians and the public.
The goal of this project is to examine the role elected leaders’ actions, individually and collectively, have regarding the relationship elected leaders in other jurisdictions have with their constituents. Using advanced methodological approaches, I investigate whether elected officials’ actions in one jurisdiction influence the representation relationship between contemporary elected officials and their constituents in other jurisdictions and whether this influence is positive or negative. For this project, I focus exclusively on the policy-related actions of elected officials and the policy preferences of constituents. The advanced methodological techniques I use allow me to model the actions of an individual politician, or an entire government, as dependent on the actions of their neighbors. I find that accounting for the interdependence among representatives is crucial for understanding political representation.
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Tino, Peter. "Spatial representation of symbolic sequences through iterative function systems." SFB Adaptive Information Systems and Modelling in Economics and Management Science, WU Vienna University of Economics and Business, 1998. http://epub.wu.ac.at/926/1/document.pdf.
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Jeffrey proposed a graphic representation of DNA sequences using Barnsley's iterative function systems. In spite of further developments in this direction (Oliver et. al, 1993), (Roman-Roldan et. al, 1994), (Li, 1997), the proposed graphic representation of DNA sequences has been lacking a rigorous connection between its spatial scaling characteristics and the statistical characteristics of the DNA sequences themselves. We 1) generalize Jeffrey's graphic representation to accommodate (possibly infinite) sequences over an arbitrary finite number of symbols, 2) establish a direct correspondence between the statistical characterization of symbolic sequences via Renyi entropy spectra and the multifractal characteristics (Renyi generalized dimensions) of the sequences' spatial representations, 3) show that for general symbolic dynamical systems, the multifractal fH-spectra in the sequence space coincide with the fH-spectra on spatial sequence representations. (author's abstract)Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"
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Howarth, Richard J. "Spatial representation, reasoning and control for a surveillance system." Thesis, Queen Mary, University of London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369664.
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Dent, Kevin. "Representation and capacity in visual-spatial short-term memory." Thesis, Lancaster University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418879.
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Yuen, Kin-sun, and 袁建新. "Solving mathematical problems: a verificationof a spatial representation model." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1988. http://hub.hku.hk/bib/B31231470.
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UGULINO, WALLACE CORBO. "WEARABLES FOR SUPPORTING SPATIAL REPRESENTATION ACQUISITION BY BLIND PERSONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25005@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
A dificuldade de locomoção de pedestres cegos é um problema complexo constituído das dificuldades de percepção e de orientação. Parte da dificuldade de percepção é identificar pontos de referência, que é necessário para que indivíduos montem uma representação do espaço, orientem-se nesse espaço e definam trajetórias para se locomover. Nessa pesquisa, foram desenvolvidos e investigados wearables para apoiar indivíduos cegos a identificar pontos de referência. O primeiro Estudo de Caso foi realizado para investigar uma maneira de evitar o masking, problema causado pela tecnologia que consiste numa sobrecarga cognitiva e no prejuízo temporário da capacidade do indivíduo de sensoriar o ambiente com seus sentidos. Para investigar o masking, foram realizados Estudos de Caso com participantes cegos e wearables propostos nessa pesquisa. A partir dos estudos, conclui-se que o wearable dessa pesquisa foi bem sucedido em evitar o masking e essa abordagem foi considerada uma alternativa válida para pesquisadores que investigam esse problema em outros contextos. No segundo Estudo de Caso, já com o masking controlado, concluiu-se que o wearable proposto nessa pesquisa possibilita aos indivíduos cegos explorar mais pontos de referência em relação à exploração exclusivamente com a bengala. Essa pesquisa contribui também com um conjunto de recomendações para projetistas de wearables para mobilidade de cegos.
The difficulty in the locomotion of blind pedestrians is a complex problem that comprises the difficulties of perception and orientation. Part of the difficulty of perception is the identification of landmarks, which is necessary for the orientation process and also the acquisition of a spatial representation. The spatial representation will be used later when orientating in this space and for defining paths to move from a given place to another. In this research, wearables were investigated aiming at supporting blind persons in the task of identifying of landmarks. The first step was to investigate a way to avoid masking, a problem caused by technology that is characterized by a cognitive overload and the harmful interference of technology in the wearer’s capabilities of sensing the environment through their senses. In order to investigate masking, a Case Study was designed and carried out with a group of blind subjects. As a result, the wearable succeeded in avoiding masking. The approach used is considered useful as an alternative for researchers that investigate this problem in other contexts. Besides avoiding the masking, the proposed wearable enabled blind individuals explore more landmarks when compared to the approach of exploring with a white cane. Furthermore, this research also contributes with a set of recommendations for designers of wearables for blind mobility.
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Haralambidou, Penelope. "The blossoming of perspective : an investigation of spatial representation." Thesis, University College London (University of London), 2003. http://discovery.ucl.ac.uk/39777/.
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Cockings, Samantha. "Automated zone design for the spatial representation of population." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/368175/.
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Any mapping or analysis involving population data aggregated to geographical areas (zones) is subject to the modifiable areal unit problem (MAUP), namely that observed patterns are influenced by both the scale (size) and aggregation (boundary placement) of zones. This has important implications, not only for researchers undertaking analyses, but also for national statistical organisations needing to decide what zoning system(s) (sets of zones) to employ to release population data. This thesis explores, enhances and extends automated zone design techniques for the spatial representation of population. It addresses three key themes: the use of automated zone design to explore the modifiable areal unit problem; automated maintenance and adaptation of existing zoning systems; and the importance of building blocks in automated zone design. It shows that administrative geographies are not necessarily the most appropriate zones for exploring health and environment relationships and that automated zone design can be used to explore sensitivity of results to the MAUP. It demonstrates that automated procedures can be used to update existing zoning systems which have become unfit for purpose due to population change, and also to modify existing zones to make them suitable for representation of other phenomena such as workplace statistics. It provides evidence that building blocks are a crucial, but under-rated, component of the zone design process and concludes that all zone design should be based on sound theoretical reasoning and a clear conceptualisation of the phenomena and processes being represented. The thesis has had a demonstrable impact on the fields of environment and health, and official population statistics; its concepts and methods have been employed by a diverse range of researchers, as well as by the Office for National Statistics to create 2011 Census output areas and workplace zones for England and Wales.
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D'Albis, Tiziano. "Models of spatial representation in the medial entorhinal cortex." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19306.
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Komplexe kognitive Funktionen wie Gedächtnisbildung, Navigation und Entscheidungsprozesse hängen von der Kommunikation zwischen Hippocampus und Neokortex ab. An der Schnittstelle dieser beiden Gehirnregionen liegt der entorhinale Kortex - ein Areal, das Neurone mit bemerkenswerten räumlichen Repräsentationen enthält: Gitterzellen. Gitterzellen sind Neurone, die abhängig von der Position eines Tieres in seiner Umgebung feuern und deren Feuerfelder ein dreieckiges Muster bilden. Man vermutet, dass Gitterzellen Navigation und räumliches Gedächtnis unterstützen, aber die Mechanismen, die diese Muster erzeugen, sind noch immer unbekannt. In dieser Dissertation untersuche ich mathematische Modelle neuronaler Schaltkreise, um die Entstehung, Weitervererbung und Verstärkung von Gitterzellaktivität zu erklären.
Zuerst konzentriere ich mich auf die Entstehung von Gittermustern. Ich folge der Idee, dass periodische Repräsentationen des Raumes durch Konkurrenz zwischen dauerhaft aktiven, räumlichen Inputs und der Tendenz eines Neurons, durchgängiges Feuern zu vermeiden, entstehen könnten. Aufbauend auf vorangegangenen theoretischen Arbeiten stelle ich ein Einzelzell-Modell vor, das gitterartige Aktivität allein durch räumlich-irreguläre Inputs, Feuerratenadaptation und Hebbsche synaptische Plastizität erzeugt.
Im zweiten Teil der Dissertation untersuche ich den Einfluss von Netzwerkdynamik auf das Gitter-Tuning. Ich zeige, dass Gittermuster zwischen neuronalen Populationen weitervererbt werden können und dass sowohl vorwärts gerichtete als auch rekurrente Verbindungen die Regelmäßigkeit von räumlichen Feuermustern verbessern können. Schließlich zeige ich, dass eine entsprechende Konnektivität, die diese Funktionen unterstützt, auf unüberwachte Weise entstehen könnte.
Insgesamt trägt diese Arbeit zu einem besseren Verständnis der Prinzipien der neuronalen Repräsentation des Raumes im medialen entorhinalen Kortex bei.High-level cognitive abilities such as memory, navigation, and decision making rely on the communication between the hippocampal formation and the neocortex. At the interface between these two brain regions is the entorhinal cortex, a multimodal association area where neurons with remarkable representations of self-location have been discovered: the grid cells. Grid cells are neurons that fire according to the position of an animal in its environment and whose firing fields form a periodic triangular pattern. Grid cells are thought to support animal's navigation and spatial memory, but the cellular mechanisms that generate their tuning are still unknown. In this thesis, I study computational models of neural circuits to explain the emergence, inheritance, and amplification of grid-cell activity. In the first part of the thesis, I focus on the initial formation of grid-cell tuning. I embrace the idea that periodic representations of space could emerge via a competition between persistently-active spatial inputs and the reluctance of a neuron to fire for long stretches of time. Building upon previous theoretical work, I propose a single-cell model that generates grid-like activity solely form spatially-irregular inputs, spike-rate adaptation, and Hebbian synaptic plasticity. In the second part of the thesis, I study the inheritance and amplification of grid-cell activity. Motivated by the architecture of entorhinal microcircuits, I investigate how feed-forward and recurrent connections affect grid-cell tuning. I show that grids can be inherited across neuronal populations, and that both feed-forward and recurrent connections can improve the regularity of spatial firing. Finally, I show that a connectivity supporting these functions could self-organize in an unsupervised manner. Altogether, this thesis contributes to a better understanding of the principles governing the neuronal representation of space in the medial entorhinal cortex.
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Topaloglou, Theodoros. "On the representation of partial spatial information in knowledge bases." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0019/NQ28307.pdf.
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Bek, Judith. "Language and Spatial Representation : Evidence from Dual-Tasking and Aphasia." Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521920.
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Tan, Chee Khoon. "Fuzzy spatial representation and sensory integration for mobile robot task." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409387.
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Heide, David C. "Kant's Idealism: On the Character and Limits of Spatial Representation." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1283966702.
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Pech, Palacio Manuel Alfredo. "Spatial data modeling and mining using a graph-based representation." Lyon, INSA, 2005. http://theses.insa-lyon.fr/publication/2005ISAL0118/these.pdf.
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Est proposé un unique modèle basé sur des graphes pour représenter des données spatiales, les données non-spatiales et les relations entre les objets spatiaux. Ainsi un graphe est généré à partir de ces trois éléments. On considère que l'outil de fouille de données basé sur les graphes peut découvrir des patterns incluant ces trois éléments, selon trois types de relation spatiale (topologique, cardinale et de distance). Dans notre modèle, les données spatiales, non-spatiales (attributs non-spatiaux), et les relations spatiales représentent une collections d'un ou plusieurs graphes orientés. Les sommets représentent soit les objets spatiaux, soit les relations spatiales entre deux objets spatiaux, ou les attributs non-spatiaux. De plus, un sommet peut représenter soit un attribut, soit le nom d'une relation spatiale. Les noms des attributs peuvent référencer des objets spatiaux ou non-spatiaux. Les arcs orientés sont utilisés pour représenter des informations directionnelles sur les relations entre les éléments, et pour décrire les attributs des objets. On a adopté SUBDUE comme un outil de fouille de graphes. Une caractéristique particulière dite de recouvrement joue un rôle important dans la découverte de patterns. Cependant, elle peut-être implémentée pour recouvrir la totalité du graphe, ou bien ne considérer aucun sommet. En conséquence, nous proposons une troisième piste nommée recouvrement limité, laquelle donne à l'utilisateur la capacité de choisir le recouvrement. On analyse directement trois caractéristiques de l'algorithme proposé, la réduction de l'espace de recherche, la réduction du temps de calcul, et la découverte de patterns grâce à ce type de recouvrementWe propose a unique graph-based model to represent spatial data, non-spatial data and the spatial relations among spatial objects. We will generate datasets composed of graphs with a set of these three elements. We consider that by mining a dataset with these characteristics a graph-based mining tool can search patterns involving all these elements at the same time improving the results of the spatial analysis task. A significant characteristic of spatial data is that the attributes of the neighbors of an object may have an influence on the object itself. So, we propose to include in the model three relationship types (topological, orientation, and distance relations). In the model the spatial data (i. E. Spatial objects), non-spatial data (i. E. Non-spatial attributes), and spatial relations are represented as a collection of one or more directed graphs. A directed graph contains a collection of vertices and edges representing all these elements. Vertices represent either spatial objects, spatial relations between two spatial objects (binary relation), or non-spatial attributes describing the spatial objects. Edges represent a link between two vertices of any type. According to the type of vertices that an edge joins, it can represent either an attribute name or a spatial relation name. The attribute name can refer to a spatial object or a non-spatial entity. We use directed edges to represent directional information of relations among elements (i. E. Object x touches object y) and to describe attributes about objects (i. E. Object x has attribute z). We propose to adopt the Subdue system, a general graph-based data mining system developed at the University of Texas at Arlington, as our mining tool. A special feature named overlap has a primary role in the substructures discovery process and consequently a direct impact over the generated results. However, it is currently implemented in an orthodox way: all or nothing. Therefore, we propose a third approach: limited overlap, which gives the user the capability to set over which vertices the overlap will be allowed. We visualize directly three motivations issues to propose the implementation of the new algorithm: search space reduction, processing time reduction, and specialized overlapping pattern oriented search
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Pech, Palacio Manuel Alfredo Laurini Robert Tchounikine Anne Sol Martínez David. "Spatial data modeling and mining using a graph-based representation." Villeurbanne : Doc'INSA, 2006. http://docinsa.insa-lyon.fr/these/pont.php?id=pech_palacio.
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Thèse doctorat : Informatique : Villeurbanne, INSA : 2005. Thèse doctorat : Informatique : Universidad de las Américas - Puebla : 2005.Thèse soutenue en co-tutelle. Thèse rédigée en français, en anglais et en espagnol. Titre provenant de l'écran-titre. Bibliogr. p. 174-182.
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Wallgrün, Jan Oliver. "Hierarchical Voronoi graphs spatial representation and reasoning for mobile robots." Berlin Heidelberg Springer, 2008. http://d-nb.info/99728210X/04.
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Yuen, Kin-sun. "Solving mathematical problems : a verification of a spatial representation model /." Hong Kong : [University of Hong Kong], 1988. http://sunzi.lib.hku.hk/hkuto/record.jsp?B10398120.
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Baguley, Thomas Simon. "The representation of spatial mental models in long-term memory." Thesis, Open University, 1994. http://oro.open.ac.uk/57430/.
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This thesis is concerned with how people understand and remember spatial information derived from verbal descriptions. The thesis distinguishes between three different ways of representing spatial information in working memory. The first way is to represent the surface form of the source from which the spatial information is derived (the language of a description). The second is to represent the structure of the situation derived from that source (a spatial mental model). The third is to represent the perceptual characteristics of the situation from a particular perspective (a visual image). Considerable evidence exists that people construct and manipulate spatial mental models in working memory. The purpose of this thesis is to investigate the claim that mental models are represented in long-term memory. An outline of the spatial mental modeling processes required to understand a simple spatial description is proposed. It is proposed that spatial mental modeling is comprised of three processing stages. Firstly, comprehension processes are required to access the linguistic meaning of information presented in spatial description. Secondly, construction processes are required to build up a representation of the spatial structure of the situation derived from the language of the description. Thirdly, consultation processes are required to monitor construction and to access information from the spatial mental model. Nine experiments are reported which investigate evidence for and against the view that people remember the construction and consultation of a spatial mental model. In the final chapter this evidence is reviewed and a 'sketch' of a processing theory of memory for spatial descriptions is proposed. It is argued that memory for a spatial mental model is a product of the interaction between construction and consultation processes over a period of time rather than a simple 'copy' of a completed working memory spatial mental model.
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Briceño, Domínguez Raimundo José. "Combinatorial aspects of spatial mixing and new conditions for pressure representation." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58876.
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Over the last few decades, there has been a growing interest in a measure-theoretical property of Gibbs distributions known as strong spatial mixing (SSM). SSM has connections with decay of correlations, uniqueness of equilibrium states, approximation algorithms for counting problems, and has been particularly useful for proving special representation formulas and the existence of efficient approximation algorithms for (topological) pressure. We look into conditions for the existence of Gibbs distributions satisfying SSM, with special emphasis in hard constrained models, and apply this for pressure representation and approximation techniques in Z^d lattice models. Given a locally finite countable graph G and a finite graph H, we consider Hom(G,H) the set of graph homomorphisms from G to H, and we study Gibbs measures supported on Hom(G,H). We develop some sufficient and other necessary conditions on Hom(G,H) for the existence of Gibbs specifications satisfying SSM (with exponential decay). In particular, we introduce a new combinatorial condition on the support of Gibbs distributions called topological strong spatial mixing (TSSM). We establish many useful properties of TSSM for studying SSM on systems with hard constraints, and we prove that TSSM combined with SSM is sufficient for having an efficient approximation algorithm for pressure. We also show that TSSM is, in fact, necessary for SSM to hold at high decay rate. Later, we prove a new pressure representation theorem for nearest-neighbour Gibbs interactions on Z^d shift spaces, and apply this to obtain efficient approximation algorithms for pressure in the Z² (ferromagnetic) Potts, (multi-type) Widom-Rowlinson, and hard-core lattice gas models. For Potts, the results apply to every inverse temperature except the critical. For Widom-Rowlinson and hard-core lattice gas, they apply to certain subsets of both the subcritical and supercritical regions. The main novelty of this work is in the latter, where SSM cannot hold.Science, Faculty of
Mathematics, Department of
Graduate
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Emamjome, Meisam. "Spatial representation by a combination of grid cells and place cells." Thesis, University of Surrey, 2009. http://epubs.surrey.ac.uk/843604/.
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Animals are capable of navigating through an environment. This requires them to recognise, remember and relate positions. Spatial representation is one of the main tasks during navigation. The brain seems to have a world centric positioning system such that we remember positions of objects in relation to a reference frame. Such spatial representation is believed to have been constructed in the hippocampus and related brain areas. Place cells, head direction cells, grid cells and border cells seem to transform vestibular information to spatial information in the brain. However, when psychological studies reveal how these areas are connected together, the process of transforming vestibular information to the kind of representation seen in place cells is still in question. In this thesis, we develop a hypothetical model, consisting of head direction cells, grid cells, sensory cells, border cells, place cells and connections between each. Our aim here is to create a biologically feasible spatial representation of the environment with activity patterns of neurons in the model similar to firing patterns of place cells in the hippocampus. With this model, we simulate a subset of the components in order to develop a spatial representation. This subset consists of a single dimension head direction representation, periodic two dimension grid cells representation, and finally a monotonic two dimension place cell representation. We offer two approaches for connections between grid cells and place cells, hardwired and learnt connections. The hardwiring approach provides us an understanding of how grid cell firing can be transformed into place cell representation. The learning approach illustrates a biologically plausible method in the development of spatial representation. Our results show that it is possible to achieve spatial representation by use of Bienenstock, Cooper and Munro (BCM) learning method which has a dynamic threshold. To further evaluate our model and determine its practical application we embed it in a mobile robot. A robotic implementation provides an opportunity for us to evaluate the model under the presence of noise both in the internal information and from the environment. Although our robotic experiments are limited, they demonstrate that our model provides a fundamental biologically plausible infrastructure for robotic navigation.
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Wolter, Diedrich. "Spatial representation and reasoning for robot mapping a shape-based approach." Berlin Heidelberg Springer, 2006. http://d-nb.info/989966941/34.
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Cheewinsiriwat, Pannee. "Development of a 3D geospatial data representation and spatial analysis system." Thesis, University of Newcastle Upon Tyne, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.514467.
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Sun, Linus Da-Shih 1972. "Impaired and enhanced spatial representation of the PSD-95 knockout mouse." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/27046.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, June 2004.Includes bibliographical references (p. 175-185).
Postsynaptic density protein-95 (PSD-95) is the second most abundantly expressed synaptic protein in the postnatal forebrain. It is an integral part of the postsynaptic scaffolding complex and helps recruit receptors, channels and associated factors involved with synaptic transmission. A mouse whose wildtype gene was replaced with truncation mutant of PSD-95 preserving two PDZ binding domains causes a spatial learning and memory deficit and a dramatic enhancement of synaptic strengthening. Long Term Potentiation is enhanced at all frequencies of stimulation (1-100Hz), while Long Term Depression is absent in the mutants. This study explores CA1 pyramidal cell spatial representations in the PSD-95 mutant mice. Mutants are not significantly different than controls in running velocity. Nor are its pyramidal cells or interneurons different than controls in: place cell firing rates, sparsity of run active cells, bursting behavior, or theta modulated activity. However, mutants do exhibit significantly larger place fields and wider spike waveforms. Mutants also expressed enhanced directionality of place fields and increased post-run sleep correlation of firing for overlapping place fields. Mutants also exhibited disruption of asymmetrical place fields and phase precession, the first such observation reported in mice. In conclusion, LTP alone is not enough for the active process of encoding experience. Instead, bi-directional synaptic plasticity is necessary for proper place field formation, correlation, directionality, asymmetry, phase precession, and the formation of spatial memories.
by Linus Da-Shih Sun.
Ph.D.
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Wolter, Diedrich. "Spatial representation and reasoning for robot mapping a shape-based approach /." Berlin : Springer, 2008. http://www.myilibrary.com?id=186085.
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Rooney, Nuala. "At home with density spatial representation in Hong Kong public housing." Thesis, Edinburgh Napier University, 1997. http://researchrepository.napier.ac.uk/Output/3801.
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This study examines the representation of space in high-density Hong Kong public housing. Over half the population in Hong Kong lives in public housing yet little is known about how they physically cope with density through everyday dwelling. Specifically, this post-occupancy study attempts to highlight the context of high density dwelling as a legitimate dwelling experience. It focuses on residents' interpretation and conception of space and examines problem-solving in the everyday context of high density living. The research is presented as a narrative highlighting spatial sensibilities in a culture of density. It traces the development of housing forms from early Hong Kong to the establishment of the Government housing programme. It will be argued that the combination of a massive influx of a refugee population, and a shortage of housing in the Territory created a situation where low-level design standards in public housing were not only accepted by the population but became the norm. Through qualitative interviews with long-term residents of public housing this study proposes to question assumptions of Western spatial thinking within domestic space. It looks at the way in which the changing habitus has been affected by social mobility and shifting cultural values of space; in particular, it examines how different generations living in the same household perceive and represent their home. This thesis contributes to an emerging field of design knowledge. It is a reflective study which, it is anticipated, will provide other designers with insight into lived-in qualities of density and residents' ability to articulate design knowledge. It seeks to challenge designers' preconceptions of density and the performance of professional design knowledge in the interpretation of everyday space.
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Peterle, Giada. "Enacting Literary Geographies: Urban Narratives from Space Representation to Spatial Practices." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3425306.
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This work aims to address the emerging field of geohumanities, with particular attention to the approaches and methodologies developed in the field of literary geography. The six chapters focus on different urban contexts (North-eastern Italy's polinucleated city, international metropolises such as New York and Berlin, the Po Delta region) and disparate literary works and genres (novels, short stories collections, graphic novels and comic books) to analyse the representation and experience of contemporary urban life from a mobile geocritical perspective. Particular attention is paid to the narrative representation of urban practices, as well as to the exploration of interdisciplinary research methods informed by both urban/cultural geography and literary theory and criticism.Il lavoro si rivolge all'ambito delle geohumanities, facendo particolare riferimento agli approcci e alle metodologie della geografia letteraria. I sei capitoli si concentrano su diversi contesti urbani (la città polinucleare del Nord est, metropoli internazionali come New York e Berlino, il delta del Po) e su opere letterarie appartenenti a generi letterari differenti (romanzi, raccolte di racconti, graphic novel) per analizzare la rappresentazione e l'esperienza urbana contemporanea da una prospettiva geocritica mobile. Particolare attenzione è quindi rivolta alla raffigurazione narrativa delle pratiche urbane, ma anche all'esplorazione di metodi di ricerca interdisciplinari tra geografia urbana e culturale e teoria e critica letteraria.
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SPOSITO, AMBRA VALENTINA. "The spatial metric representation of body parts: behavioural and neuropsychological evidence." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2011. http://hdl.handle.net/10281/20101.
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The mental representation of the body is being a subject of intensive research from different perspectives starting from the 20th Century. Indeed, the body is a peculiar object for the brain, being at the same time a physical, space-occupying object and the critical mean for perception and action in the world around us. The present doctoral work focussed on the spatial representation of the body; in particular it was investigated whether the body holds a specific metric representation, which is supposed to be useful for action programming and interaction with the environment, as introduced in Chapter 1. To this aim Experimental Part 1 (Chapter 2 and 3) investigated the stable properties of the body metrics, while Experimental Part 2 (Chapter 4) focussed on its plastic and dynamic features. Chapter 2 discusses the differences between the spatial metric representation of body parts and non bodily three-dimensional objects. In particular, Experiment 1 investigated the possibility that Unilateral Spatial Neglect (USN) may affect to a different extent the spatial analysis of body parts relative to extrapersonal three-dimensional objects. Participants were required to bisect their left forearm and a length-matched cylinder with their right index finger. Both USN patients and neurologically unimpaired participants showed a significantly more accurate estimation of the subjective midpoint of the forearm, relative to the solid object. Besides the main pattern of an advantage in the forearm bisection, a further analysis suggested the possibility of a double dissociation, with two patients exhibiting the opposite advantage in the solid bisection. Experiment 2, asking unimpaired volunteers to perform the same bisection task in three different conditions (Forearm, Fake Forearm, Cylinder), showed a similar kind of spatial analysis for stimuli displaying bodily features, either real or fake, relative to non-corporeal objects. Thus, it can be suggested that the spatial processing of body parts critically depends upon their prototypical visuo-spatial shape and that the spatial metrics of body parts, relatively to noncorporeal objects, is also more resistant to the disruption of spatial processing and representation brought about by USN. Chapter 3, starting from recent evidence showing how the body can be used as an intrinsic metric system for the representation of near space, illustrates how the length of extrapersonal objects can be scaled using the metric representation of body parts, and to what extent a higher-order metric representation of the body relays upon the somatosensory system. Experiment 3 showed, by means of a bisection task, that the spatial encoding of an extracorporeal object (i.e., a cylinder) may be facilitated by the presence of the forearm in that space –i.e. when the forearm was placed inside the cylinder- as if participants can unconsciously rely on its well known metric representation in order to better estimate the length of the cylinder. In Experiment 4 the same task was administered to a group of right-brain damaged patients, with or without somatosensory and proprioceptive defict, and to a matched control group. The results showed that the spatial metric representation of body parts might be distorted, or even not available, when the somatosensory sensitivity is altered by a cerebral lesion. Data about the plasticity of the metric representation of body parts are presented in Chapter 4. In this last group of experiments, blindfolded participants were required to perform a radial proprioceptive bisection of their forearm before and after a training with a tool, which allowed an extension of the action space in the far space. The results of Experiment 5 supported the working hypothesis that the arm metric representation can be changed by tool-use. In this experiment participants performed a radial bisection of their arm and indicated the subjective midpoint of their arm more distally after the training, suggesting that the perceived length of their own arm was increased. Interestingly, no effect was obtained following a training with a shorter tool (i.e., 20 cm long). Experiment 6 further supported this interpretation by showing, through a proprioceptive control task, that the dynamic lengthening induced in the metric representation of the arm was not due to a mere illusory distal drift of the whole arm. Furthermore, it demonstrated that the spatial metric representations of the dominant and the non-dominant arms share similar plastic features, being both equally prone to be modified by tool use. In conclusion this doctoral work showed that body size holds a mental representation that is very stable (even more than that of extrapersonal objects), but also characterized by flexible functional plasticity.
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Hodgson, Eric P. "The interaction of transient and enduring spatial representations using visual cues to maintain perceptual engagement /." Oxford, Ohio : Miami University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1217959226.
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Santos-Pata, Diogo. "The Dynamics of hippocampal encoding: beyond the spatial metaphor." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/587163.
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Every animal on our planet wanders around when looking for something. Whether it is in search of food, a mate, or home, navigation is one of the most performed cognitive behaviors in Nature. Nevertheless, our understanding of how the brain is capable of solving such a simple problem − to move from one point to another − is still incomplete. The decomposition of navigation into cognitive components reveals the complexity of such behavior. To reach a goal, one has to first understand its current position, then to estimate the target position, followed by identifying a route towards the goal-location and, finally, to physically orchestrate a set of motor-actions leading to the desired location. Extensive research on the mammalian hippocampus has revealed its critical role in spatial navigation, memory, and learning. However, the mechanisms for spatial memory encoding, episodic representation, and their behavioral counterparts are still not fully understood. Moreover, we do not know if the mechanisms involved in spatial re- presentation also scale up to conceptual representation from a purely spatial domain, such as task cognitive demands. In this thesis, we present a set of studies focused on spatial and cognitive representation in the insect and mammalian organisms. We show that the problem of spatial representation requires multi-level solutions working simultaneously: from biophysical neuronal mechanisms to behavioral aspects of navigation. Furthermore, with physiological studies of the human medial temporal lobe, we propose that the mechanisms involved in spatial representation also extend to higher-order cognitive representations, therefore suggesting that the hippocampus handles information that is dimension independent.Tots els animals del nostre planeta passegen mentre busquen alguna cosa. Ja sigui per trobar menjar, parella o un lloc per viure, la nave- gacio` `es un dels comportaments cognitius més realitzats en la natura. No obstant, la nostra comprensió de com el cervell és capaç de resoldre aquest senzill problema − moure’s d’un punt a un altre − encara és incompleta. La descomposició de la navegació en diferents components cognitius revela la complexitat d’aquest comportament. Per assolir un objectiu, hom ha de primer conèixer la seva posició, llavors estimar la posició destí, seguidament identificar una ruta o camí fins a aquesta i, finalment, orquestrar un conjunt d’accions motores que portin fins a la posició desitjada. L’àmplia recerca de l’hipocamp en mamífers ha revelat el seu paper fonamental en la navegació espacial, la memòria i l’aprenentatge. Tot i això, els mecanismes de codificació de la memòria espacial, la representació episódica i els seus homólegs encara no s’han pogut entendre completament. Tanmateix, encara no sabem si els mecanismes involucrats en la representació espacial també escalen des d’un domini purament espacial a la representació de conceptes, com ara les necessitats cognitives d’una tasca. En aquesta tesi presentem un conjunt d’estudis centrats en la representació espacial i cognitiva en el cervell d’insectes i mamífers. Mostrem que el problema de la representació espacial requereix de solucions amb múltiples nivells treballant simultàniament: des dels mecanismes neuronals biofísics fins als aspectes conductuals de la navegació. Per últim, a partir d’estudis fisiológics del lobul temporal mitjà de l’ésser humà, proposem que els mecanismes involucrats en la representació espacial també s’extenen a representacions cognitives d’alt nivell, suggerint que l’hipocamp s’encarrega de la informació independentment de la seva dimensió.
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Kanaparthy, Venu Madhav Singh. "GML REPRESENTATION FOR INTEROPERABLE SPATIAL DATA EXCHANGE IN A MOBILE MAPPING APPLICATION." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07102004-133629/.
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Geographic information is critical to GIS applications located remotely for executing business operations. GIS applications need to interoperate to be able to share information for analysis and decision making process. Heterogeneity and complexity of information models and structures limit the data flow and application interoperation. Advancements in Internet technologies provided new opportunities for delivering spatial information to remote users. However, spatial data delivered is in proprietary structures, limiting the utility to GIS applications. To enable information flow between GIS applications a portable data modeling approach is necessary. However, geographic information is inherently complex to model. A comprehensive and standardized vocabulary to model characteristics of geographic entities is required. Furthermore applications with the need to share information should have an agreement on information structure and content exchanged. This research presents GML representation to provide interoperable spatial data services. The objective is achieved by providing an open framework to model, encode and delivery geographic information. The results of this research show that it is possible to develop interoperable spatial data services through service oriented architecture.
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Zhang, Yuan 1976. "An efficient coding method for spatial data : the rotating, hierarchical, overlapping representation." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29552.
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A new, efficient image compression algorithm based on a rotating, overlapping, hierarchical representation (ROHR) is presented. This algorithm first decomposes the spatial image data into a hierarchical coordinate space, composed of interconnected nodes. The surprise of each node represents the entropy of the corresponding image area, and determines its significance in reconstructing the image. Surprises are ordered and transmitted in decreasing order of magnitude with a bucket encoding method, yielding an embedded code. ROHR allows for either lossless compression, or for termination of the encoding or decoding at any point to meet a target compression ratio or distortion metric. In the latter; image reconstruction from the transmitted data occurs without the introduction of artifacts that would indicate where the truncation occurred. Moreover, the procedures allow for real-time video encoding or decoding operations on color images of 256 x 192 pixels on current PC architectures, considerably faster than equivalent software JPEG codecs.
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Zara, Cristiana. "Sacred journeys and profane travellers : representation and spatial practice in Varanasi (India)." Thesis, University of London, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553833.
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This thesis is concerned with tourist representations and practices in India. Orientalist aesthetics have often associated this country with notions of spirituality and mysticism; tourist narratives sustain and reinforce such representations by describing India as a land of ancient rituals and timeless traditions. The visual construction of India's 'spiritual landscapes' has been largely deployed as a powerful tool for subduing the unfamiliar Other within reassuring epistemological categories. However, tourism research has recently become interested in exploring the role of tourist practices in landscape production. Not only do tourists 'gaze upon' landscapes, they also script landscapes through practices and performances. By focusing on the case of Varanasi, the Indian pilgrimage city on the banks of the Ganges, this thesis shows how tourist practices (re)produce and make sense of the city's 'sacredscape'. Special attention is paid to the riverfront, which epitomizes the cultural and spiritual significance ascribed to the city. Both Hindu and tourist narratives depict the riverfront as embodying a special power, a unique meaning, whether this uniqueness is held to be a 'spiritual' or a 'picturesque' one. The thesis analyses the city's riverfront asthe place where tourist, ritual, and day-to-day activities are played out and negotiated, and where the aesthetics of landscape is confronted with the materialities and the practices inherent to this place. The research has adopted an ethnographic approach, combining participant observation, interviews and questionnaires, visual methods, and textual analysis of popular tourist literature.
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Nilsen, Karen Elisabeth. "The spatial representation of a tone on the guinea pig basilar membrane." Thesis, University of Sussex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311413.
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Bai, Paul. "Beyond the Dialectical: An Exploration of Spatial Representation in Contemporary Art Practice." Thesis, Griffith University, 2015. http://hdl.handle.net/10072/365357.
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This research explores the spatial options that exist beyond conventional dualisms. Specifically, this exegesis is the result of four years of studio and theoretical research surrounding the research question: How can a Third Spatial Position enable contemporary art practice to move beyond conventional spatial dialectics?
This research is organised around four major components. Firstly, I introduce a series of theoretical findings to demonstrate the possible existence of a Third Spatial Position that is based on in-between space, and can be described as transitional, situational, open and indeterminate. Secondly, I examine the role of space in major shifts of art practice since 1960 to demonstrate that spatial dualisms featured prominently in these art practices and limited their attempt to contextualise themselves outside of the boundaries conventionally ascribed to art. Thirdly, I provide an analysis of key contemporary artworks by international artists that demonstrate an uneasy relationship with spatial dualisms and substantial tendencies towards adopting a Third Spatial Position. Finally, I provide an overview of my own studio output over the course of my candidature. As I describe, these works deconstruct the physical and conceptual structure of spatial representation, through emphasising the indeterminate and open nature of space, thus revealing the Third Spatial Position.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Queensland College of Art
Arts, Education and Law
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FULMER, HILARY RENEE. "VISUAL INFLUENCES ON LIMITATIONS OF SPACE: SPATIAL DEPTH PERCEPTION VERSUS SPATIAL DEFINITION." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147885019.
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McGraw, Tammy M. "The Effects of Two-Dimensional and Three-Dimensional Stimuli on Spatial Representation in Drawings." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30315.
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Visual learning experiences are becoming increasingly prevalent in education as symbols, imagery and simulations replace traditional text-based materials. Although the utilization of images for instructional purposes is not a new occurrence, most images used in instruction have been two-dimensional representations, giving learners little experience working with three-dimensional images. Little research has been done to explain the effects of two-dimensional and three-dimensional stimuli on the learning process.
This study examined the effects of two-dimensional and three-dimensional stimuli on spatial representation in drawings. Through the use of stereopsis, a scene was projected as both a two-dimensional image and as a three-dimensional image. Students wore polarizing glasses to enable them to perceive the superimposed images as a three-dimensional scene; whereas a single slide was projected when the image was to be perceived as a two-dimensional scene. Four test groups were established from eighth grade students who elected to take art. Participants in Group A were ask to draw the scene from the two-dimensional stimulus and, a week later, from the three-dimensional stimulus. Group B was asked to draw the scene from the three-dimensional stimulus and, a week later, from the two-dimensional stimulus. Group C drew only from the two-dimensional stimulus while Group D drew only from the three-dimensional stimulus.
In all groups, participants were asked to draw the scene as realistically as possible using a graphite pencil. The completed drawings were evaluated for evidence of spatial cues and the students' perception and response to spatial information.Ph. D.
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Vasudevan, Shrihari. "Spatial cognition for mobile robots : a hierarchical probabilistic concept-oriented representation of space." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17612.
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Alkan, Alper Semih. "Framing The Invisible:section As A Spatial Frame For A Reconsideration Of Architectural Representation." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605390/index.pdf.
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This thesis is a critical reconsideration of the relationship of architectural production with its modes of representation. Historically, the representation of architecture has been signifying an interval where the displacement between the mental conception and its material expression has taken place. The group composed of plan, section and elevation is called orthographic set, which has been accepted as a universal code in architecture since it is attributed with the basic premise of its being objective and international. It is this attributed character of the drawings, which will be investigated in respect to the act of sectioning. Section displays an ambiguous character that it is the picture plane and the act of cutting at once. This study is a critical redefinition of section as a spatial act of framing. The construction of picture plane is discussed as a specific condition of framing, thus of sectioning.
Like the specificity of the perspectival representation, the section constructs its own frame, in which the physical cut into the body of architectural object and its flattened spatial depth overlap. Therefore, section is redefined as the operation of a spatial framing, which rather hides than displays. It is in this hidden dimension that the epistemological value in architectural representation lies.
The significance of the picture plane, that is the incision plane, is revealed by its relation to the constitution of perspective and projective drawings. The related concept of projection, whose mode strictly corresponds to the distance stimulated by the mode of projection, provides not only a critical distance but also brings about the operations to overcome that distance. In this respect, acknowledging section in architectural representation as a conceptual spatial frame, the study tries to reveal the inherent depth of the medium of representation, which is sometimes more promising than what is displayed in.
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Wolter, Diedrich [Verfasser]. "Spatial representation and reasoning for robot mapping : a shape-based approach / Diedrich Wolter." Berlin, 2008. http://d-nb.info/989966941/34.
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Zarzeczna, Natalia. "Powerful males on top : spatial simulations in the mental representation of gender stereotypes." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/119449/.
Full textAbstract:
The theory of grounded cognition proposes that abstract thinking involves mental simulations of acquired sensorimotor experiences. In this thesis, my primary aim was to investigate whether the mental representation of gender stereotypes is related to sensorimotor experiences associated with space. In a series of experiments, I asked participants to complete a spatial task and categorise as quickly as possible which person (one female name; one male name) of two vertically displayed on the screen (top and bottom) was socially powerful or powerless. As predicted, stereotypically constructed power-gender associations involved simulations of males as powerful at the top as opposed to females as powerful at the top. This was specific to spatial location, as males as powerful, but not females, were chosen faster at the top than at the bottom. Further, I replicated the above findings using pupillometry. Additional mechanisms as well as consequences of spatial simulations were further examined. I found that spatial simulations in gender-power associations are dependent on simultaneous power and gender salience. Finally, I demonstrate that spatial features involved in the representation of gender stereotypes have consequences for gender perceptions by promoting stereotype-consistent thinking. Altogether, my studies show that the representation of power and gender involves spatial simulations that are influenced by stereotypic thinking. When making judgements about power differences, the spatial cues and socially constructed stereotypical beliefs compete for activation to accomplish conceptual integration and produce meaning. Such findings imply that mental representations of stereotype-consistent knowledge are more pronounced as they involve concrete spatial simulations.