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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.
1

Underwater Wireless Sensor Network Deployment forWater Pollution Monitoring in Rivers / Déploiement des réseaux de capteurs sous-marins pour la surveillance de la pollution dans une rivière

Khalfallah, Zakia 16 December 2015 (has links)
L'Internet des objets est un domaine en plein essor, qui a reçu une attention considérable à la fois académique et industrielle. En particulier, les réseaux de capteurs sans fil connectent les objets à Internet via une passerelle. Dans ce contexte, les réseaux de capteurs sous-marins sont un axe de recherche très récent qui joue un rôle clé dans plusieurs applications de surveillance, semblant être primordiales envers l’environnement et la santé humaine. Par conséquent, un déploiement judicieux et efficace des réseaux des capteurs sous-marins s’avère crucial. Dans cette thèse, nous abordons la problématique du déploiement 3D des réseaux de capteurs sous-marins dans une rivière caractérisée par l’irrégularité géographique de l’événement à surveiller. Notre application spécifique concerne la surveillance de la qualité de l’eau dans les rivières. L’instabilité de la qualité de l’eau est à l’origine de la répartition non uniforme de la pollution dans l’environnement 3D sous-marin. Dans cette optique, nous étudions séparément le déploiement 3D des réseaux de capteurs sous-marins pour détecter la pollution issue i) d’une substance chimique liquide et ii) d’un contaminant solide. Ces problèmes de déploiement sont NP-difficile et exigent une optimisation combinatoire judicieuse. Afin de surmonter cette complexité, nous proposons plusieurs heuristiques de déploiement et nous abordons le problème en trois étapes. En premier lieu, notre objectif est la génération de la meilleure topologie des stations géographiques de détection afin d’assurer la détection totale de la substance chimique le long de la rivière. Pour cela, nous proposons une première stratégie, BackTracking Field Installation Deployment Algorithm (BT-FIDA), basée sur l’algorithme du Backtracking. Par la suite, nous étudions la meilleure topologie des capteurs chimiques au sein de chaque station de détection. L’objectif est d’assurer une barrière de couverture totale de la substance polluante avec le minimum de coût. La solution est obtenue grâce à notre deuxième proposition, 2D-Underwater Barrier Deployment Algorithm (2D-UBDA), basée sur une optimisation non-linéaire et mixte. Enfin, on s’intéresse à la détection d’un polluant de type solide pour garantir la qualité de surveillance et la connectivité du réseau tout en minimisant le coût de déploiement. Pour cela, nous proposons une nouvelle heuristique de déploiement, 3D-UWSN-Deploy, basée sur la répartition cubique du volume surveillé et l’optimisation linéaire et mixte. Les résultats obtenus confirment une performance satisfaisante de nos algorithmes par rapport à la littérature. / The Internet of Things (IoT) is a booming field that has received considerable attention from both academy and industry. In particular, wireless sensor networks are connecting things to the Internet through a gateway. In this context, Underwater Wireless Sensors Network (UWSN) is a very recent network topic which is playing a key role in several sensing application, seeming to be mandatory towards environment and human health. Thus, suitable deployment of underwater sensors for efficient monitoring is a crucial task. In this thesis, we address the issue of deploying an underwater sensor network in a 3D area characterized by the geographical irregularity of the sensed event. Our specific application context regards the water river monitoring. The irregularity of water quality in river comes from the unsteady repartition of pollution within the 3D water environment. In this context, we separately study the 3D underwater sensor deployment problem to detect water pollution issued from i) chemical liquid and ii) solid wastes. The deployment problems require combinatorial optimization and are NP-hard. To overcome the great complexity involved, we propose several heuristic deployment strategies and we tackle the problem in three stages. In the first stage, our objective is to generate the best deployment of geographical Field Installations (FIs) to ensure the full detection of chemical pollutant along the river. An FI can be seen as a virtual wall able to detect the moving pollutant chemical substance over it. For this, we propose a novel backtracking-based deployment strategy named BackTracking Field Installation Deployment Algorithm (BT-FIDA) which minimizes the number of FIs while ensuring full coverage of the river. In the second stage, we aim to find the best topology of chemical sensors inside an FI in order to form a barrier detection of the polluting substance with the minimum deployment cost. This is performed thanks to our second proposal based on a mixed integer optimization namely 2D Underwater Barrier Deployment Algorithm (2D-UBDA). Finally, in the third stage, we move to the detection of a solid pollutant within an FI. Our objective is to minimize the number of deployed underwater sensors while ensuring i) the required Quality of Monitoring (QoM) (i.e., differentiated probabilistic detection) and ii) wireless network connectivity. To generate the best topology, we propose a novel deployment heuristic, named 3D-UWSN-Deploy, based on a sub-cube tessellation of the monitored FI and a mixed integer linear program optimization. Simulation results show that our contributions outperform the related deployment strategies.
2

A degrada??o ambiental e a exclus?o social: estudo de caso do Munic?pio de Lorena/SP

SANTOS, Filipe Vieira Fernandes dos 10 April 2015 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-07T19:38:56Z No. of bitstreams: 1 2015 - Filipe Vieira Fernandes dos Santos.pdf: 71967729 bytes, checksum: bcf82dcfd407a8d39096eda9faf6ab07 (MD5) / Made available in DSpace on 2017-04-07T19:38:56Z (GMT). No. of bitstreams: 1 2015 - Filipe Vieira Fernandes dos Santos.pdf: 71967729 bytes, checksum: bcf82dcfd407a8d39096eda9faf6ab07 (MD5) Previous issue date: 2015-04-10 / Historically, the region of ?Vale do Para?ba? has suffered a severe depredation of its forest richness and in the last 50 years a considerable demographic expansion associated with an intense and diversified industrial development has intensified the degradation of its natural resources. This paper studies Tabo?o, Mandi and Quatinga brooks, and these three have some common characteristics: they are watersheds in the municipality of Lorena and the tributaries of the right bank of the Para?ba do Sul river. They born in the rural area and in a transversal way, they cross the city through rural and urban-industrial landscapes and conservation areas. The three brooks face problems such as lack of basic sanitation, waste disposal and irregular occupation of permanent preservation areas. The aim of this study is to analyze the sensibility of the environmental degradation indicators along to these three water bodies in relation to the ?lex? (Exclusion Index), which is obtained through the Exclusion Map method. The Exclusion Map uses intra-municipal data from a demographic census of 2010, carried out by the Brazilian Institute of Geography and Statistics (IBGE) and its goal is to diagnose socio-economic indicators in different parts of the territory, that are more related to the environmental degradation and, consequently, to corroborate for a continuo process of public policies formulation that are dedicated to seek a sustainable development. / A regi?o do Vale do Para?ba historicamente sofreu intensa depreda??o de suas riquezas florestais e nos ?ltimos 50 anos consider?vel expans?o demogr?fica que associada a um desenvolvimento industrial intenso e diversificado, intensificou a degrada??o de seus recursos naturais. Este trabalho estuda os ribeir?es Tabo?o, Mandi e Quatinga, os tr?s possuem caracter?sticas em comum: s?o microbacias do munic?pio de Lorena, afluentes da margem direita do Rio Para?ba do Sul, nascem na zona rural e cortam o munic?pio na transversal passando por paisagens rurais, urbano-industriais e de ?reas de preserva??o. Os tr?s ribeir?es enfrentam problemas como falta de saneamento b?sico, descarte de res?duos e ocupa??o irregular das ?reas de preserva??o permanente. O estudo visa analisar a sensibilidade dos indicadores de degrada??o ambiental ao longo destes corpos d'?gua em rela??o ao Iex (?ndice de Exclus?o), que ? obtido atrav?s do m?todo do Mapa de Exclus?o, que utiliza dados intra-municipais do Censo Demogr?fico de 2010, realizado pelo IBGE (Instituto Brasileiro de Geografia e Estat?stica), com objetivo de diagnosticar os indicadores s?cio-econ?micos, nas diferentes parcelas do territ?rio, que se relacionam com maior signific?ncia ? degrada??o ambiental e assim, corroborar para um processo cont?nuo de formula??o de pol?ticas p?blicas voltadas ? busca por um desenvolvimento sustent?vel.
3

Field-based measurement of hydrodynamics associated with engineered in-channel structures : the example of fish pass assessment

Kriechbaumer, Thomas January 2016 (has links)
The construction of fish passes has been a longstanding measure to improve river ecosystem status by ensuring the passability of weirs, dams and other in- channel structures for migratory fish. Many fish passes have a low biological effectiveness because of unsuitable hydrodynamic conditions hindering fish to rapidly detect the pass entrance. There has been a need for techniques to quantify the hydrodynamics surrounding fish pass entrances in order to identify those passes that require enhancement and to improve the design of new passes. This PhD thesis presents the development of a methodology for the rapid, spatially continuous quantification of near-pass hydrodynamics in the field. The methodology involves moving-vessel Acoustic Doppler Current Profiler (ADCP) measurements in order to quantify the 3-dimensional water velocity distribution around fish pass entrances. The approach presented in this thesis is novel because it integrates a set of techniques to make ADCP data robust against errors associated with the environmental conditions near engineered in-channel structures. These techniques provide solutions to (i) ADCP compass errors from magnetic interference, (ii) bias in water velocity data caused by spatial flow heterogeneity, (iii) the accurate ADCP positioning in locales with constrained line of sight to navigation satellites, and (iv) the accurate and cost-effective sensor deployment following pre-defined sampling strategies. The effectiveness and transferability of the methodology were evaluated at three fish pass sites covering conditions of low, medium and high discharge. The methodology outputs enabled a detailed quantitative characterisation of the fish pass attraction flow and its interaction with other hydrodynamic features. The outputs are suitable to formulate novel indicators of hydrodynamic fish pass attractiveness and they revealed the need to refine traditional fish pass design guidelines.
4

Determination of water body structures for small rivers using remote sensing data

Karrasch, Pierre, Henzen, Daniel, Hunger, Sebastian, Hörold, Max 29 August 2019 (has links)
The diversity of habitats in water bodies like rivers is characterised by the status of morphological and hydrological conditions. The good ecological status of water bodies is claimed in the EuropeanWater Framework Directive. For the assessment of this status the hydro-morphology is one of the most important supporting components for the classification of the ecological status of water bodies. Therefore the periodical monitoring is a mandatory measure in the scope of the European Water Framework Directive. Regarding the so called overview-method of the LAWA (German Working Group on water issues of the Federal States and the Federal Government represented by the Federal Environment Ministry) the use of remote sensing data and remote sensing methodologies becomes more important. Therefore remote sensing data on different scales (satellite, aerial photographs) as well as other topographic information (ATKIS) and a high resolution DTM are merged into an integrative process of analysis using remote sensing and GIS methodology. The analyses ared focused on two parameters. First, a detailed landuse classification based on LANDSAT satellite data is performed for whole catchment of a small river. The results show significant increase of urban areas close to the river. The second analyses deals with the determination of river curvature and introduces the use of a quasi-continously representation of the river. An additional challenge is the chosen study area of a low mountain range river. While large rivers are clear visible in remote sensing data, the usability and transformation of the well-established algorithms and work ows to small rivers need a further substantial research.

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