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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Geografický informační systém pro pasportizaci a vizualizaci rozlehlých počítačových sítí / GEO Information System for Passportization and Visualization of Wide Computer Networks

Fibich, Ondřej January 2014 (has links)
The thesis is focused on the problem of the passportization and the visualization of wide computer networks with the usage of geographic information systems. It discusses principals and properties of geographic information systems and spatial databases that are frequently used as data carriers for geographic information systems. The main part of the thesis is dedicated to the passportization of computer networks with focusing on the physical network structure. After the definition of the passport format the thesis continues with the analysis, the proposal, the implementation and the testing of the geographic information system for managing and visualization of the passport in this format. The thesis is ended by a case study that demonstrates the passportization process of an access computer network in the implemented system.
32

Spatial Indexing on Flash-based Solid State Drives / Espacial em Dispositivos de Estado Sólido baseados em Memória Flash

Carniel, Anderson Chaves 21 December 2018 (has links)
Spatial database systems widely employ spatial indexing structures to speed up the processing of spatial queries. Many of the proposed spatial indices in the literature, such as the R-tree, assume magnetic disks (i.e., HDDs) as the underlying storage device. They are termed as disk-based spatial indices. On the other hand, several spatial database applications are increasingly using flash-based Solid State Drives (SSDs) and thus, designing spatial indices for these storage devices has gained increasing attention. This is due the fact that, compared to HDDs, SSDs offer smaller size, lighter weight, lower power consumption, better shock resistance, and faster reads and writes. Hence, specific indices for SSDs, termed flash-aware spatial indices, have been proposed in the literature to deal with the intrinsic characteristics of SSDs, such as the asymmetric costs of reads and writes. However, the research to date has not been able to establish a flash-aware spatial index that actually exploits all the benefits of SSDs. This PhD thesis advances on the literature as follows. We firstly define a methodology to create spatial datasets for experimental evaluations. We also propose FESTIval, a versatile framework that provides a common and unique environment to execute experimental evaluations. Such contributions served as a foundation to conduct performance analysis along this PhD work. By using this foundation, we analyze the performance behavior of spatial indices on different storage devices, such as HDDs and SSDs. Further, we discuss the applicability of employing flash simulators on the evaluation of spatial indices. The findings of these experiments contributed to the proposal of eFIND, a generic and efficient framework for flash-aware spatial indexing. eFIND is generic because it can port a wide range of disk-based spatial indices to SSDs. eFIND is also efficient because it is based on a set of design goals that exploits SSD performance. Performance tests showed that, compared to the state of the art, eFIND improved the construction of ported disk-based spatial indices and the execution of spatial queries. For porting the R-tree (i.e., the eFIND R-tree), eFIND showed performance reductions from 43% to 77% to build spatial indices, and from 4% to 23% to execute spatial queries. For porting the xBR+-tree (i.e., the eFIND xBR+-tree), eFIND showed reductions from 28% to 83% to build spatial indices and up to 35% in the spatial query processing. / Sistemas de banco de dados espaciais empregam estruturas de indexação espaciais para acelerar o processamento de consultas espaciais. Muitos dos índices espaciais propostos na literatura, como a R-tree, assumem que os dispositivos de armazenamentos são os discos magnéticos (i.e., HDDs) e são denominados índices espaciais baseados em disco. Por outro lado, várias aplicações de banco de dados espaciais estão cada vez mais usando Solid State Drives (SSDs) baseados em memória flash e, assim, projetar índices espaciais para esses dispositivos tem ganhado cada vez mais atenção. Isso se deve ao fato de que, em comparação com os HDDs, os SSDs oferecem menor tamanho, menor peso, menor consumo de energia, melhor resistência a choques além de leituras e escritas mais rápidas. Assim, índices espaciais para memória flash têm sido propostos na literatura para lidar com as características intrínsecas dos SSDs, como os custos assimétricos de leituras e escritas. No entanto, a pesquisa até o momento não conseguiu estabelecer um índice espacial que realmente explora todos os benefícios dos SSDs. Esta tese de doutorado avança na literatura da seguinte forma. Primeiramente, é definida uma metodologia para criar conjuntos de dados espaciais para avaliações experimentais. Também é proposto FESTIval, um arcabouço versátil que fornece um ambiente comum e único para executar avaliações experimentais. Tais contribuições serviram como base para conduzir análises de desempenho ao longo deste trabalho de doutorado. Usando essa base, o comportamento de desempenho de índices espaciais em diferentes dispositivos de armazenamento, como HDDs e SSDs, é analisado. Além disso, discutese a aplicabilidade de simuladores flash na avaliação experimental de índices espaciais. Os resultados desses experimentos contribuíram para a proposta de eFIND, uma estrutura genérica e eficiente para indexação espacial em memórias flash. eFIND é genérico porque pode portar uma ampla gama de índices espaciais baseados em disco para SSDs. eFIND também é eficiente porque é baseado em um conjunto de objetivos de projeto que exploram o desempenho do SSD. Os testes de desempenho mostraram que, em comparação com o estado da arte, eFIND melhorou a construção de índices espaciais portados e a execução de consultas espaciais. Para portar a R-tree (ou seja, a eFIND R-tree), eFIND mostrou melhorias de desempenho de 43% a 77% para construir índices espaciais e de 4% a 23% para executar consultas espaciais. Para portar a xBR+-tree (ou seja, a eFIND xBR+-tree), eFIND mostrou melhorias de 28% a 83% para construir índices espaciais e de até 35% no processamento de consultas espaciais.
33

CORREÇÃO DE DADOS AGROMETEOROLÓGICOS UTILIZANDO MÉTODOS ESTATÍSTICOS

Baba, Ricardo Kazuo 31 July 2012 (has links)
Made available in DSpace on 2017-07-21T14:19:32Z (GMT). No. of bitstreams: 1 Ricardo Baba.pdf: 3642224 bytes, checksum: 81e8e78f554cdf870e6f9a554b71f87a (MD5) Previous issue date: 2012-07-31 / Climatic data are more and more important to predict climate phenomena or to evaluate historical data that serve as support for decision making especially for agriculture. Ensuring the quality of these data is crucial. These data are collected by the meteorological stations, during this process some data gaps and data inconsistent may be generated. Identify suspicious or inconsistent data is very important to ensure data quality. This paper presents an approach that uses statistical and geostatistical techniques to identify incorrect and suspicious data and estimate new values to fill gaps and errors. In this research, a spatial database was used to implement these techniques (statistical and geostatistical) and to test and evaluate the weather data. To evaluate these techniques we used data from stations located in Paraná State to evaluate the temperature variable. To check the results of the estimated data, we used the mean absolute error (MAE) and the root mean square error (RMSE). As a result, the uses of these techniques have proved to be suitable to identify basic errors and historical errors. The temporal validation showed a poor performance by overestimating the amount of incorrect data. Regarding the estimation techniques applied Kriging, Inverse of Distance Weighted and Linear Regression, all showed similar performance in the error analysis. / A análise de dados climáticos serve de suporte na previsão de fenômenos relacionados, na avaliação de seus dados históricos e para a tomada de decisões, em especial na área da agricultura. Garantir a sua qualidade é fundamental. O processo de coleta desses dados, através das estações meteorológicas, pode apresentar problemas, onde dados inconsistentes podem ser geridos ou obtidos. A identificação de dados inconsistentes ou suspeitos é de fundamental importância na garantia de qualidade dos dados. Este trabalho apresenta uma abordagem para solução do problema, utilizando técnicas estatísticas e geoestatísticas na identificação de dados inconsistentes e na estimativa de dados a serem corrigidos ou preenchidos. A implementação destas técnicas em um banco de dados espacial apresentou-se como um facilitador na identificação e no preenchimento desses dados. Para avaliação destas técnicas utilizou-se de dados das estações localizadas no Estado do Paraná, para análise da variável temperatura. Para avaliar os resultados, foram utilizados os erros médio e quadrático. Como resultado, destaca-se que as técnicas de identificação de erros mostraram-se adequadas na consistência de erros básicos e históricos. A validação espacial apresentou baixo desempenho por superestimar a quantidade de dados incorretos. Quanto as técnicas utilizadas na estimativa dos dados, Krigagem, Inverso da Distância e Regressão Linear, todas apresentaram desempenho semelhantes com relação à análise dos erros.
34

Analýza dosahu signálu bezdrátových sítí / Analysis of Wireless Signal Coverage

Šimek, Petr January 2017 (has links)
This master's thesis describes process of design and development of the system for calculating the coverage of wireless networks, it is implemented as a web portal and written in the Java programming language. The text of the thesis describes the work with the used platforms, a description of the ITU-R calculation method P.1812, which is used for calculation electric field strength and basic information about electromagnetic waves. The main function of the system is to calculate and display coverage of wireless networks and customer management information.
35

La problématique de l'information territoriale et ses enjeux majeurs dans les pays du Sud : stratégie, méthodologie et projet pilote dans un pays en développement, le Mali / The problematic of territorial information and its major challenges in the countries of the South : strategy, methodology and pilot project in a developing country, Mali

Dakouo, Alain Bessiba 26 June 2019 (has links)
En Afrique, la décentralisation s'effectue dans des contextes variables selon les pays: la nécessité de réformer l'Etat suite à une crise, la volonté d'instaurer une démocratie locale pour compenser le pouvoir central voire dictatorial, parfois même l'incapacité de l'Etat à fournir les services socioéconomiques de base comme la santé, l'éducation, l'eau potable etc.En Afrique de l'Ouest, la décentralisation s’est souvent accompagnée d’un redécoupage des territoires dans les années 1990. La plupart des pays d’Afrique de l'Ouest ont créé trois niveaux de collectivités territoriales: la Région, le Département (Cercle au Mali) et la Commune. Ceci entraîne un besoin de gestion et d’aménagement du territoire à plusieurs échelles (état des lieux, suivi de l’emprise spatiale de l’aménagement, assainissement, gestion des ressources naturelles, développement économique rural, santé, éducation, hydraulique, gestion des risques etc.). Dans le cadre d’un besoin d’informations croissant, les partenaires au développement reconnaissent l’utilité du Système d'Information Géographique (SIG), comme outil d'aide à la décision. La création de différents ministères en lien avec l’information géographique au Mali, nécessite la mise en commun de compétences s’articulant autour de la géomatique. En effet, si chaque Institution et ministère sectoriel dispose de données thématiques propres, leur valorisation se heurte à une forte dispersion et disparité des données géographiques et cartographiques.Comment mutualiser un même système géospatial et territorial entre une mairie, une collectivité territoriale, une ONG, l’Etat ainsi que d’autres partenaires travaillant sur une même emprise territoriale ? Quelle stratégie d’information territoriale pour un pays comme le Mali ?L’objectif de ce travail de thèse est de mettre en place, selon les concepts, méthodes, et technologies de la géographie actuelle et de la statistique, un outil d’aide à la décision dans un contexte de mutualisation et de décentralisation, conçu pour faire franchir un pas décisif au bénéfice de l'aménagement territorial local, par une mise en cohérence et une mise à disposition des données géolocalisées nécessaires à une politique efficace d'aménagement du territoire. Cette perspective à caractère stratégique implique de remonter jusqu'aux aspects de la répartition des pouvoirs, les rapports entre les logiciels libres et payants, l’information participative (aspects sociétal, social, contexte ethnique...) et le développement de l’information géographique au Mali. Une stratégie d’information est en fait un préalable indispensable de toute stratégie d’aménagement et de développement. Le projet de thèse se veut un projet innovant cherchant à fournir des réponses sur la mise en place d’une telle politique de gestion multi-sources et multi-acteurs de l’information spatiale dans un pays en développement. / In Africa, decentralization takes place in contexts that vary from country to country: the need to reform the Government following a crisis, the desire to establish local democracy to compensate for central or even dictatorial power, sometimes even the Government 's inability to provide basic socio-economic services such as health, education, drinking water, etc.In West Africa, decentralization was often accompanied by a redrawing of territories in the 1990s. Most West African countries have created three levels of local authorities: the Region, the Department (Cercle in Mali) and the Commune. This leads to a need for territory management and planning on several scales (inventory, monitoring of the environmental impact of development, sanitation, natural resource management, rural economic development, health, education, hydraulics and risk management). In the context of a growing need for information, development partners recognize the usefulness of the Geographic Information System (GIS) as a tool for decision making. The creation of different ministries in connection with geographic information in Mali requires pooling of skills centered on geomatics. Indeed, while each Institution and sectoral ministry has its own thematic data, their valuation is hampered by a high dispersion and disparity of geographical and cartographic data.How to share a common geospatial and territorial system across a town hall, a local authority, an NGO, the Government as well as other partners working on the same territorial? What territorial information strategy for a country like Mali?The aim of this thesis is to create, according to the concepts, methods, and technologies of current geography and statistics, a tool to support decision making in a context of overlapping responsibilities/actions and decentralization, designed to take a decisive step forward for the benefit of local territorial planning, by making coherent and available the geolocalized data necessary for an effective spatial planning policy. This strategic perspective implies going back to the distribution of powers, the ratio between free and paid software, participative information (societal, social, ethnic aspects, etc.) and the development of geographical information in Mali.An information strategy is in fact an essential prerequisite for any planning and development strategy. This thesis is an innovative project that will aim to provide answers on the implementation of such a strategy of multi-source and multi-stakeholder spatial information management in a developing country.
36

Using Digital Mapping Techniques to Rapidly Document Vulnerable Historical Landscapes in Coastal Louisiana: Holt Cemetery Case Study

Moore, Alahna 18 May 2018 (has links)
This thesis outlines a technique for rapid documentation of historic sites in volatile cultural landscapes. Using Holt Cemetery as an exemplary case study, a workflow was developed incorporating RTK terrain survey, UAS aerial imagery, photogrammetry, GIS, and smartphone data collection in order to create a multifaceted database of the material and spatial conditions, as well as the patterns of use, that exist at the cemetery. The purpose of this research is to create a framework for improving the speed of data creation and increasing the accessibility of information regarding threatened cultural resources. It is intended that these processes can be scaled and adapted for use at any site, and that the products generated can be utilized by researchers, resource management professionals, and preservationists. In utilizing expedited methods, this thesis specifically advocates for documentation of sites that exist in coastal environments and are facing imminent destruction due to environmental degradation.

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