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Geographically weighted spatial interaction (GWSI)Kordi, Maryam January 2013 (has links)
One of the key concerns in spatial analysis and modelling is to study and analyse similarities or dissimilarities between places over geographical space. However, ”global“ spatial models may fail to identify spatial variations of relationships (spatial heterogeneity) by assuming spatial stationarity of relationships. In many real-life situations spatial variation in relationships possibly exists and the assumption of global stationarity might be highly unrealistic leading to ignorance of a large amount of spatial information. In contrast, local spatial models emphasise differences or dissimilarity over space and focus on identifying spatial variations in relationships. These models allow the parameters of models to vary locally and can provide more useful information on the processes generating the data in different parts of the study area. In this study, a framework for localising spatial interaction models, based on geographically weighted (GW) techniques, has been developed. This framework can help in detecting, visualising and analysing spatial heterogeneity in spatial interaction systems. In order to apply the GW concept to spatial interaction models, we investigate several approaches differing mainly in the way calibration points (flows) are defined and spatial separation (distance) between flows is calculated. As a result, a series of localised geographically weighted spatial interaction (GWSI) models are developed. Using custom-built algorithms and computer code, we apply the GWSI models to a journey-to-work dataset in Switzerland for validation and comparison with the related global models. The results of the model calibrations are visualised using a series of conventional and flow maps along with some matrix visualisations. The comparison of the results indicates that in most cases local GWSI models exhibit an improvement over the global models both in providing more useful local information and also in model performance and goodness-of-fit.
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La distanza conta: Tre elaborati in Economia Spaziale / DISTANCE MATTERS: THREE ESSAYS IN SPATIAL ECONOMIC ANALYSISCALEGARI, ELENA 27 May 2016 (has links)
Waldo Tobler, con la sua prima legge della geografia, afferma “Ogni cosa è correlata con qualsiasi altra, ma le cose vicine sono più relazionate di quelle lontane" (Tobler, 1970). Se questo era certamente vero nel 1970, tale convinzione è stata messa in discussione con l’avvento delle Tecnologie dell’Informazione e della Comunicazione (ICT). Nel dibattito riguardo al processo di globalizzazione molti studiosi e giornalisti sostengono infatti che, con la velocizzazione delle telecomunicazioni, la distanza fisica è destinata a perdere il proprio potere esplicativo relativamente a molti fenomeni socio-economici (Cairncross, 2001; Friedman, 2005). Questa dissertazione vuole contribuire al dibattito rispondendo, seppure parzialmente, alla domanda “La distanza importa ancora?” e definire alcune possibili implicazioni di policy. L’obiettivo è quello di mostrare il ruolo della distanza geografica in tre diversi contesti economici caratterizzati da differenti dimensioni dell’unità di analisi. I risultati suggeriscono che, anche se su scala globale lo sviluppo delle nuove tecnologie ha modificato la percezione individuale della distanza come deterrente alle interazioni, lo spazio geografico mantiene ancora la sua rilevanza del definire le relazioni socio-economiche locali, aumentando il ruolo di città e regioni quali centri della maggioranza delle attività economiche. / Waldo Tobler, with his first law of geography, stated “Everything is related to everything else, but near things are more related than distant things" (Tobler, 1970). If it was certainly true in 1970, this belief is called into question in an era of development of Information and Communication Technologies (ICTs). In the debate over globalization processes, several scholars and journalists argue indeed that, with the increasing speed of telecommunications, physical distance is losing its explanatory power as determinant of socio-economical relationships (Cairncross, 2001; Friedman, 2005). This dissertation aims to give a contribution to this debate, partially answering to the broad question “Does distance still matter?" and to draw possible policy implications. The purpose is to show the role of geographical distance in three different economic environments, characterized by diversified size of the unit of analysis. Results suggest that, even if at a global scale improvements in ICTs have changed the individual perception of the distance as deterrent in interactions, geographical space still maintains its relevance in defining local socio-economic relationships, increasing the role of cities and regions as the core of most of economic activities.
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Explorando alternativas para construção de modelos neurais de interação espacial / Exploring alternatives for the construction of neural spatial interaction modelsAkamine, Alexandra 27 September 2005 (has links)
O rápido crescimento das cidades brasileiras, não acompanhado de um planejamento prévio de sua expansão (incluindo o uso e a ocupação do solo), vem acarretando transtornos à comunidade no que se refere aos deslocamentos, visto que estes se tornam cada vez maiores. Devido a isso, torna-se necessário um conhecimento das demarcações das áreas do município, dos tipos de serviços atualmente prestados à comunidade em cada área e dos usuários destes serviços, não só em termos quantitativos, mas principalmente no que diz respeito à sua distribuição no espaço. Mais ainda, o conhecimento da evolução da demanda no tempo e a sua localização espacial permitem a avaliação de inúmeros cenários de gestão da demanda e da oferta, possibilitando, por exemplo, prever em qual região haverá um crescimento maior da primeira. Outros aspectos que devem ser avaliados são a origem, o destino e o volume de deslocamentos que ocorrem em um determinado conjunto de zonas, o que pode ser estimado através de modelos de interação espacial. Neste sentido, foram realizados estudos com o objetivo de avaliar o desempenho de modelos de interação espacial construídos com Redes Neurais Artificiais (RNAs). Observou-se nestes estudos, uma carência de técnicas para seleção da rede neural a ser utilizada na modelagem, ou seja, a rede com melhor desempenho e poder de predição. Tal como a maioria dos trabalhos que utilizam Redes Neurais Artificiais para este tipo de modelagem, os parâmetros de rede são escolhidos aleatoriamente e, ainda que se consiga resultados satisfatórios variando-se tais parâmetros, nem sempre a rede utilizada representa a solução ótima. O objetivo desta pesquisa é avaliar o uso de diferentes alternativas, tais como a técnica de otimização de Algoritmos Genéticos (AGs) na seleção de Redes Neurais Artificiais e o método de estimação por bootstrap na divisão dos dados, para a construção de modelos de interação espacial, e avaliar a distribuição espacial dos resíduos (erros) das previsões. O estudo foi desenvolvido em um Sistema de Informações Geográficas (SIG) e os dados empregados para este fim refletem a evolução espacial da demanda por serviços municipais de educação numa cidade média brasileira (São Carlos, SP) ao longo de dois anos. Os resultados deste trabalho mostraram que, embora a utilização dos modelos neurais seja apropriada para a estimativa de fluxos, a partir do método gravitacional é possível mensurar de forma precisa e aceitável o crescimento e a distribuição espacial da demanda futura por serviços de educação, permitindo-se identificar quais devem ser as melhores ações a serem tomadas pelo poder público no presente com o intuito de reduzir as distâncias de deslocamento dos alunos no futuro. Isto é particularmente importante para ações de planejamento, em virtude da simplicidade do modelo e de sua fácil e direta implementação / The rapid growth of Brazilian cities, without a previous planning of their expansion (including land use and occupation), causes many inconveniences for the population related to their transportation, as they must cover longer distances. This asks for an understanding of the city areas limits, the services currently offered to the community in each area, and the users of these services, not only in quantitative terms, but also in terms of spatial distribution. Moreover, the knowledge of the demand evolution in time and its spatial location allows the evaluation of many planning scenarios for managing the demand and the supply, and it is possible, for example, to foresee the regions where the demand is going to be concentrated. Other aspects that must be evaluated are the origin, destination and number of trips that occur in a determined set of tracts, which can be predicted by the spatial interaction models. Therefore, some studies were made with the objective of evaluating the performance of Spatial Interaction Models based on Artificial Neural Networks (ANNs). It was observed in these studies, some difficulty in selecting the neural network configuration that best models the problem. As in the majority of research that uses Artificial Neural Networks for the construction of that kind of model, the network parameters are randomly chosen and, even if one can obtain satisfactory results by varying these parameters, the neural net used may not be producing the optimal solution. The objective of this work is to evaluate the use of different alternatives, such as the Genetic Algorithms (GAs) optimization technique and the bootstrapping estimation method, as supporting tools to select Artificial Neural Networks configurations applied to Spatial Interaction Models, and to evaluate the spatial distribution of the residual (errors) prediction results. The research was developed in a Geographic Information System (GIS) and the data used for this application reflects the changes in the spatial distribution of the demand for education services in a Brazilian medium-sized city (São Carlos, SP) throughout two years. The results obtained showed that although neural models are suitable for estimating transportation flows, gravity models are able to produce very good and precise estimates of the future spatial distribution of the demand for educational facilities. This is very important for the planning process aiming at the reduction of displacement costs of students in the future, given the simplicity of the gravity model structure and its straightforward implementation
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Explorando alternativas para construção de modelos neurais de interação espacial / Exploring alternatives for the construction of neural spatial interaction modelsAlexandra Akamine 27 September 2005 (has links)
O rápido crescimento das cidades brasileiras, não acompanhado de um planejamento prévio de sua expansão (incluindo o uso e a ocupação do solo), vem acarretando transtornos à comunidade no que se refere aos deslocamentos, visto que estes se tornam cada vez maiores. Devido a isso, torna-se necessário um conhecimento das demarcações das áreas do município, dos tipos de serviços atualmente prestados à comunidade em cada área e dos usuários destes serviços, não só em termos quantitativos, mas principalmente no que diz respeito à sua distribuição no espaço. Mais ainda, o conhecimento da evolução da demanda no tempo e a sua localização espacial permitem a avaliação de inúmeros cenários de gestão da demanda e da oferta, possibilitando, por exemplo, prever em qual região haverá um crescimento maior da primeira. Outros aspectos que devem ser avaliados são a origem, o destino e o volume de deslocamentos que ocorrem em um determinado conjunto de zonas, o que pode ser estimado através de modelos de interação espacial. Neste sentido, foram realizados estudos com o objetivo de avaliar o desempenho de modelos de interação espacial construídos com Redes Neurais Artificiais (RNAs). Observou-se nestes estudos, uma carência de técnicas para seleção da rede neural a ser utilizada na modelagem, ou seja, a rede com melhor desempenho e poder de predição. Tal como a maioria dos trabalhos que utilizam Redes Neurais Artificiais para este tipo de modelagem, os parâmetros de rede são escolhidos aleatoriamente e, ainda que se consiga resultados satisfatórios variando-se tais parâmetros, nem sempre a rede utilizada representa a solução ótima. O objetivo desta pesquisa é avaliar o uso de diferentes alternativas, tais como a técnica de otimização de Algoritmos Genéticos (AGs) na seleção de Redes Neurais Artificiais e o método de estimação por bootstrap na divisão dos dados, para a construção de modelos de interação espacial, e avaliar a distribuição espacial dos resíduos (erros) das previsões. O estudo foi desenvolvido em um Sistema de Informações Geográficas (SIG) e os dados empregados para este fim refletem a evolução espacial da demanda por serviços municipais de educação numa cidade média brasileira (São Carlos, SP) ao longo de dois anos. Os resultados deste trabalho mostraram que, embora a utilização dos modelos neurais seja apropriada para a estimativa de fluxos, a partir do método gravitacional é possível mensurar de forma precisa e aceitável o crescimento e a distribuição espacial da demanda futura por serviços de educação, permitindo-se identificar quais devem ser as melhores ações a serem tomadas pelo poder público no presente com o intuito de reduzir as distâncias de deslocamento dos alunos no futuro. Isto é particularmente importante para ações de planejamento, em virtude da simplicidade do modelo e de sua fácil e direta implementação / The rapid growth of Brazilian cities, without a previous planning of their expansion (including land use and occupation), causes many inconveniences for the population related to their transportation, as they must cover longer distances. This asks for an understanding of the city areas limits, the services currently offered to the community in each area, and the users of these services, not only in quantitative terms, but also in terms of spatial distribution. Moreover, the knowledge of the demand evolution in time and its spatial location allows the evaluation of many planning scenarios for managing the demand and the supply, and it is possible, for example, to foresee the regions where the demand is going to be concentrated. Other aspects that must be evaluated are the origin, destination and number of trips that occur in a determined set of tracts, which can be predicted by the spatial interaction models. Therefore, some studies were made with the objective of evaluating the performance of Spatial Interaction Models based on Artificial Neural Networks (ANNs). It was observed in these studies, some difficulty in selecting the neural network configuration that best models the problem. As in the majority of research that uses Artificial Neural Networks for the construction of that kind of model, the network parameters are randomly chosen and, even if one can obtain satisfactory results by varying these parameters, the neural net used may not be producing the optimal solution. The objective of this work is to evaluate the use of different alternatives, such as the Genetic Algorithms (GAs) optimization technique and the bootstrapping estimation method, as supporting tools to select Artificial Neural Networks configurations applied to Spatial Interaction Models, and to evaluate the spatial distribution of the residual (errors) prediction results. The research was developed in a Geographic Information System (GIS) and the data used for this application reflects the changes in the spatial distribution of the demand for education services in a Brazilian medium-sized city (São Carlos, SP) throughout two years. The results obtained showed that although neural models are suitable for estimating transportation flows, gravity models are able to produce very good and precise estimates of the future spatial distribution of the demand for educational facilities. This is very important for the planning process aiming at the reduction of displacement costs of students in the future, given the simplicity of the gravity model structure and its straightforward implementation
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Proposta de modelo de intera??o da Universidade Federal do Rio Grande do Norte e empresas do setor de petr?leo / Proposal of Interaction Model for Federal University of Rio Grande do Norte and Oil IndustryPerales, Wattson Jos? Saenz 27 January 2014 (has links)
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Previous issue date: 2014-01-27 / Operational procedures may negatively interfere in negotiation and execution regarding
universities and business companies. In some cases it may even derail business interaction.
Thus, aiming to overcome this and other barriers a university-industry interaction model was
structured. The model enhances the appropriation of technological solutions on behalf of
enterprises, as well as aim to improve the quality of teaching and research done at the
university. In order to conduct a case study, sampling considering the Federal University of
Rio Grande do Norte (UFRN) was made as well as the Oil and Gas sector. For data collection
questionnaires, classroom observation, document analysis, semi-structured interviews were
used. The study describes the companies as well as the internal organization of UFRN in their
interaction context. The diagnosis related to past interactions as well as the expectations of the
companies and the university s internal subjects regarding the university-industry relationship
were also studied. Thus, specific questionnaires were applied for the three types of groups:
researchers, managers and business companies. These subjects pointed out that the great deal
of barriers they identified were related to issues regarding the university internal management.
Given these barriers, the critical factors were then identified in order to overcome this reality.
Among the nine critical factors only one belongs to the macro environment, while the
remaining factors are related to organizational issues present in the university context. It was
possible to formulate a university-business interaction model one the researched focused on
the case study results and contribution from a theoretical framework that was enabled trough
literature review. The model considers all business collaboration mechanisms; it focuses on a
particular strategic productive sector and provides a co-evolution vision over time, according
to the sector?s development strategy. The need for institutionalizing the relationship with the
companies involved is pointed out. The proposed model considers all the critical factors
identified by the research; it aims long-term relationship with the company and integrates
teaching, research and extension actions. The model implementation was also considered. It
was seen that it must be done in three phases. The phases will be defined by the level of
maturity in the relationship between the university and the companies. Thus, a framework was
developed in order to assess the interaction level regarding company institutionalization.
Whilst structuring the model was a concern with replication came up. It was pointed out that
this model should not only serve to this specific case study situation. So the final result is a
model of university-industry relationship appropriate in the first instance, for UFRN, but has
applicability, in general, to any Brazilian university / Os procedimentos operacionais interferem negativamente na negocia??o e execu??o das
intera??es universidade-empresa, em alguns casos inviabilizam a intera??o. Com o prop?sito
de superar essa e outras barreiras foi estruturado um modelo de intera??o universidadeempresa
que potencializa a apropria??o de solu??es tecnol?gicas por parte das empresas,
assim como a melhoria na qualidade do ensino e da pesquisa na universidade. A partir de uma
amostragem te?rica foi escolhida a Universidade Federal do Rio Grande do Norte (UFRN) e o
setor de petr?leo do Rio Grande do Norte para conduzir um estudo de caso. Foram usados
m?ltiplos m?todos de coleta de dados: question?rios, observa??o presencial, an?lise
documental, entrevistas semiestruturadas. O estudo descreve as empresas do setor e a
organiza??o interna da UFRN como o contexto no qual acontecem as intera??es. O
diagn?stico das intera??es que j? aconteceram, assim como as expectativas das empresas e
dos atores internos sobre a rela??o universidade-empresa foi elaborado aplicando
question?rios espec?ficos para os tr?s grupos de atores: pesquisadores, gestores e empresas. A
maioria das barreiras identificadas pelos atores da intera??o est? relacionada a quest?es de
gest?o interna da universidade. Frente a essas barreiras foram identificados como fatores
cr?ticos ?queles que contribuiriam para a supera??o das mesmas. Dentre os nove fatores
cr?ticos para superar as barreiras encontradas somente um pertence ao macroambiente,
enquanto os restantes s?o fatores organizacionais da universidade. Com foco nos resultados
do estudo de caso e a contribui??o de um framework te?rico desenvolvido na pesquisa
bibliogr?fica, foram formulados os pressupostos do modelo de intera??o universidadeempresa:
considerar todos os mecanismos de colabora??o com as empresas, foco em um
determinado setor produtivo estrat?gico, vis?o de coevolu??o ao longo do tempo de acordo
com a estrat?gia de desenvolvimento do setor e necessidade de institucionaliza??o do
relacionamento com as empresas. O modelo proposto abrange todos os fatores cr?ticos
encontrados, busca o relacionamento de longo prazo com as empresas e integra as a??es de
ensino, pesquisa e extens?o. Tamb?m foi discutido o processo de implanta??o do modelo, que
dever? ser feito em tr?s fases, definidas em fun??o do n?vel de maturidade da universidade no
relacionamento com as empresas. Para tanto, foi desenvolvido um quadro de refer?ncia para
avaliar o n?vel de institucionaliza??o que a universidade atingiu na intera??o com empresas.
Na estrutura??o do modelo houve uma preocupa??o com a replica??o, de forma que o mesmo
n?o sirva somente ? situa??o espec?fica do estudo de caso realizado. Assim, o resultado final ?
um modelo de relacionamento universidade-empresa adequado ? UFRN com o potencial de
ser aplicado a qualquer universidade brasileira
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Studium interakcí částic kosmického záření při extrémně vysokých energiích / Study of Interactions of Cosmic Rays at Ultra-high EnergiesNečesal, Petr January 2015 (has links)
This thesis is dedicated to study of interactions of utra-high energy cosmic rays using measured data from the Pierre Auger Observatory, automatic alarm system called Shift Guard and analysis of correlation of temperature and detector response. The Pierre Auger Observatory is the largest experiment to study ultra-high energy cosmic rays. The assumed relation between temperature and fluorescence detector response is studied together with descriptive temperature analysis, which shows that the air-conditioning system is not able to stabilize temperature enough. The temperature influence on camera response is investigated in order to measure the calibration correction factor. Shift Guard - the alarm system dedicated to protect fluorescence detectors and data taking is introduced and its functionality is described. The alarm system informs shifters about some events and situations that can endanger detector or deteriorate data quality. The basic parameters and alarm system logic are described together with light and sound signals. The discrepancy between measured and predicted number of muons at ground level calculated by EAS generators is showed and possible sources of this disagree- ment are studied. The result of massive dark photons decay in EAS as one of exotic muon source is presented. The analysis...
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Benchmark, Explain, and Model Urban CommutingGuo, Meng 19 December 2012 (has links)
No description available.
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[en] INTERACTIVITY: DESCRIBING RESOURCES OF THE WEB IN USE IN THE DISTANCE EDUCATION. / [pt] INTERATIVIDADE: DESCREVENDO RECURSOS DA WEB EM USO NA EADHELENA MARIA GUARISCO 18 September 2003 (has links)
[pt] O objetivo deste trabalho de pesquisa foi desenvolver uma
análise sobre modelos de interação que constituem a
interatividade da World Wide Web e que estão sendo
amplamente utilizados na educação à distância. Tecida a
partir de uma posição estritamente pedagógica, a análise
desses componentes de interface com o usuário procurou
compreender as características desses modelos frente às
necessidades e dificuldades do ensino superior, para
construção do conhecimento aliada à formação de indivíduos
no âmbito da complexidade e da incerteza da
contemporaneidade. / [en] The aim of this research work was to develop an analysis on
interaction models that constitute the interactivity of the
World Wide Web and that have been used extensively in the
education at the distance. Woven starting from a position
strictly pedagogic, the analysis of these components of
user interface looked for to understand the characteristics
of those models front at the necessities and difficulties
of the higher education, for construction of the knowledge
joined with the individuals formation in the range of the
complexity and uncertainty of the contemporarity.
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City decision-making : optimization of the location and design of urban green spacesLeboeuf, Caroline 04 1900 (has links)
Le besoin grandissant pour une planification urbaine plus durable et pour des interventions publiques visant à l'amélioration du bien-être collectif, ont grandement contribué à un engouement pour les espaces verts. Les parcs sont reconnus pour leur impact positif en zone urbaine dense, et nous sommes intéressés par l'application des concepts théoriques du domaine de la recherche opérationnelle pour assister les décideurs publics afin d'améliorer l'accessibilité, la distribution et la conception des parcs. Étant donné le contexte, nous sommes particulièrement motivés par le concept d'équité, et étudions le comportement des usagers des parcs à l'aide d'un modèle d'interaction spatiale, tel qu'appliqué dans les problèmes d'emplacement d'installations dans un marché compétitif. Dans cette recherche, nous présentons un modèle d'emplacement d'installations à deux étapes pouvant être adapté pour assister les décideurs publics à l'échelle de la ville. Nous étudions spécifiquement l'application aux espaces verts urbains, mais soulignons que des extensions du modèle peuvent permettre d'aborder d'autres problèmes d'emplacements d'installations sujets à des enjeux d'équité. La première étape de notre problème d'optimisation a pour but d'évaluer l'allocation la plus équitable du budget de la ville aux arrondissements, basé sur une somme du budget pondérée par des facteurs d'équité. Dans la deuxième étape du modèle, nous cherchons l'emplacement et la conception optimale des parcs, et l'objectif consiste à maximiser la probabilité totale que les individus visitent les parcs. Étant donné la non-linéarité de la fonction objective, nous appliquons une méthode de linéarisation et obtenons un modèle de programmation linéaire mixte en nombres entiers, pouvant être résolu avec des solveurs standards. Nous introduisons aussi une méthode de regroupement pour réduire la taille du problème, et ainsi trouver des solutions quasi optimales dans un délai raisonnable. Le modèle est testé à l'aide de l'étude de cas de la ville de Montréal, Canada, et nous présentons une analyse comparative des résultats afin de justifier la performance de notre modèle. / The recent promotion of sustainable urban planning combined with a growing need for public interventions to improve well-being and health in dense urban areas have led to an increased collective interest for green spaces. Parks have proven a wide range of benefits in urban areas, and we are interested in the application of theoretical concepts from the field of Operations Research to assist decision-makers to improve parks' accessibility, distribution and design. Given the context of public decision-making, we are particularly concerned with the concept of fairness, and are focused on an advanced assessment of users' behavior using a spatial interaction model (SIM) as in competitive facility locations' frameworks. In this research, we present a two-stage fair facility location and design (2SFFLD) model, which serves as a template model to assist public decision-makers at the city-level for the urban green spaces (UGSs) planning. We study the application of the 2SFFLD model to UGSs, but emphasize the potential extension to other applications to location problems concerned with fairness and equity. The first-stage of the optimization problem is about the optimal budget allocation based on a total fair-weighted budget formula. The second-stage seeks the optimal location and design of parks, and the objective consists of maximizing the total expected probability of individuals visiting parks. Given the non-linearity of the objective function, we apply a ``Method-based Linearization'' and obtain a mixed-integer linear program that can be solved with standard solvers. We further introduce a clustering method to reduce the size of the problem and determine a close to optimal solution within reasonable time constraints. The model is tested using the case study of the city of Montreal, Canada, and comparative results are discussed in detail to justify the performance of the model.
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On the study of 3D structure of proteins for developing new algorithms to complete the interactome and cell signalling networksPlanas Iglesias, Joan, 1980- 21 January 2013 (has links)
Proteins are indispensable players in virtually all biological events. The functions of proteins are determined by their three dimensional (3D) structure and coordinated through intricate networks of protein-protein interactions (PPIs). Hence, a deep comprehension of such networks turns out to be crucial for understanding the cellular biology. Computational approaches have become critical tools for analysing PPI networks. In silico methods take advantage of the existing PPI knowledge to both predict new interactions and predict the function of proteins. Regarding the task of predicting PPIs, several methods have been already developed. However, recent findings demonstrate that such methods could take advantage of the knowledge on non-interacting protein pairs (NIPs). On the task of predicting the function of proteins,the Guilt-by-Association (GBA) principle can be exploited to extend the functional annotation of proteins over PPI networks. In this thesis, a new algorithm for PPI prediction and a protocol to complete cell signalling networks are presented. iLoops is a method that uses NIP data and structural information of proteins to predict the binding fate of protein pairs. A novel protocol for completing signalling networks –a task related to predicting the function of a protein, has also been developed. The protocol is based on the application of GBA principle in PPI networks. / Les proteïnes tenen un paper indispensable en virtualment qualsevol procés biològic. Les funcions de les proteïnes estan determinades per la seva estructura tridimensional (3D) i són coordinades per mitjà d’una complexa xarxa d’interaccions protiques (en anglès, protein-protein interactions, PPIs). Axí doncs, una comprensió en profunditat d’aquestes xarxes és fonamental per entendre la biologia cel•lular. Per a l’anàlisi de les xarxes d’interacció de proteïnes, l’ús de tècniques computacionals ha esdevingut fonamental als darrers temps. Els mètodes in silico aprofiten el coneixement actual sobre les interaccions proteiques per fer prediccions de noves interaccions o de les funcions de les proteïnes. Actualment existeixen diferents mètodes per a la predicció de noves interaccions de proteines. De tota manera, resultats recents demostren que aquests mètodes poden beneficiar-se del coneixement sobre parelles de proteïnes no interaccionants (en anglès, non-interacting pairs, NIPs). Per a la tasca de predir la funció de les proteïnes, el principi de “culpable per associació” (en anglès, guilt by association, GBA) és usat per extendre l’anotació de proteïnes de funció coneguda a través de xarxes d’interacció de proteïnes. En aquesta tesi es presenta un nou mètode pre a la predicció d’interaccions proteiques i un nou protocol basat per a completar xarxes de senyalització cel•lular. iLoops és un mètode que utilitza dades de parells no interaccionants i coneixement de l’estructura 3D de les proteïnes per a predir interaccions de proteïnes. També s’ha desenvolupat un nou protocol per a completar xarxes de senyalització cel•lular, una tasca relacionada amb la predicció de les funcions de les proteïnes. Aquest protocol es basa en aplicar el principi GBA a xarxes d’interaccions proteiques.
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