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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.
141

Critérios de avaliação de qualidade e a consolidação de assentamentos de reforma agrária no Brasil : a experiência do "Programa de Consolidação e Emancipação (auto-suficiência) de assentamentos resultantes de reforma agrária – PAC"

Oliveira, Augusto de Andrade January 2010 (has links)
Esta tese trata da questão da qualidade dos assentamentos de reforma agrária implantados no Brasil e do processo de consolidação dos mesmos, partindo da identificação e análise dos principais problemas existentes, através de estudo da vasta literatura disponível sobre este tema, problemas estes impeditivos ou retardatários ao processo de desenvolvimento dos assentamentos. O Programa de Consolidação e Emancipação (Auto-suficiência) de Assentamentos Resultantes da Reforma Agrária – PAC, criado em dezembro de 2000, pelo Instituto Nacional de Colonização e Reforma Agrária – Incra, é um dos elementos chave no contexto desta tese, em especial seus pressupostos, objetivos e estratégias/metodologia, enquanto instrumento potencial para apoiar o processo de consolidação dos assentamentos. Da mesma forma, o Sistema de Monitoramento e Avaliação do PAC – Sipac, se constituiu em um dos principais focos de análise desta tese, a partir da avaliação de cada um dos indicadores assumidos, faixas de classificação propostas, dentre outros. No processo de análise do Sipac, foram identificados e discutidos alguns dos principais problemas e inconsistências do mesmo, efetuando-se propostas de eventuaisajustes para a melhoria desta ferramenta, além de se apontar a pontecial contribuição deste instrumento para a formatação de uma proposta geral de avaliação da qualidade dos assentamentos, com vistas a consolidação efetiva dos assentamentos no país. Nesta perspectiva, o foco principal desta tese perpassa a discussão metodológica e aplicada em relação à temática dos“critérios de avaliação da qualidade dos assentamentos de reforma agrária no Brasil”. Na perspectiva aplicada da discussão proposta, foram utilizados dados relativos a seis (6) assentamentos que integraram o PAC a partir do ano de 2002, cujos dados obtidos mediante aplicação de questionário fechado junto à maioria das famílias destes assentamentos, foramanalisados segundo a perspecitva construída junto ao PAC, instrumentalizada a partir do Sipac, de caráter multidimensional, efetuando ainda uma comparação com a perspectiva dos próprios assentados em relação ao seu nível de bem estar (também instrumentalizada pelo Sipac). Do ponto de vista teórico-metodológico-empírico, destacamos como elementos inspiradores e fundamentais para o desenvolvimento desta tese, (i) o trabalho de Sen (2000), que foca o desenvolvimento enquanto “eliminação de privações de liberdade”, numa perspectiva bastante distinta da tradicionalmente utilizada (de caráter economicista) e de Mattos (2006), focado na questão da pobreza e baseada na perspectiva de Sen; (ii) a metodologia adotada por Sepúlveda (2005), que buscou instrumentalizar o conceito de Desenvolvimento Sustentável Microrregional, perspectiva esta “aperfeiçoada” por Waquil et al. (2006); bem como (iii) o trabalho realizado por Sparovek (2003), que versa justamente sobre a qualidade dos assentamentos da reforma agrária brasileira, dentre outros. Da mesma forma, a partir dos resultados auferidos na análise dos dados dos questionários aplicados, foram debatidas de forma comparativa, as diferentes perspectivas de consolidação, tendo por base a noção operacional (de consolidação), atualmente adotada pelo Incra. / This thesis addresses the issue of quality of agrarian reform settlements in place in Brazil and the consolidation of these, from the identification and analysis of the major problems through study of the vast literature on this subject, problems that hinder or delay the process of development of settlements. The Program of Consolidation and Emancipation (Selfsufficiency) Settlement Resulting from Land Reform - PAC, created in December 2000 by the National Institute of Colonization and Agrarian Reform - Incra, is a key element in the context of this thesis, in particular its assumptions, goals and strategies methodology as a potential instrument for supporting the consolidation of the settlements. Likewise, the System Monitoring and Evaluation of the PAC - Sipac, constitutes a major focus of analysis of this thesis, based on the evaluation of each indicator given, range classification proposed, among others. During the review process of Sipac were identified and discussed some major problems and inconsistencies of the same, making up proposals for possible adjustments to improve this tool, in addition to pointing the contribution of this instrument for the formatting of a general proposal assessing the quality of settlements, with a view to effective consolidation of settlements in the country. In this perspective, the main focus of this thesis permeates the methodological discussion and applied in relation to the theme of the "criteria for quality assessment of land reform settlements in Brazil. In applied perspective on the discussion, we used data for six (6) settlements that made up the PAC from the year 2002, the data obtained through a questionnaire enclosed with the majority of the families of these settlements, were analyzed with the built perspective with the PAC, manipulated from Sipac, multidimensional, making a further comparison with the perspective of the settlers themselves in relation to their level of well-being (also orchestrated by Sipac). From the standpoint of theoretical and methodological-empirical elements stand out as inspiring and crucial for the development of this thesis, (i) the work of Sen (2000), which focuses on the development as "elimination of deprivation of liberty" in a very different perspective the traditionally used (economistic character) and Mattos (2006), focused on the issue of poverty and based on the perspective of Sen, (ii) the methodology adopted by Sepúlveda (2005), which sought to equip the concept of micro-regional sustainable development, perspective "perfected" by Waquil et al. (2006), and (iii) the work done by Sparovek (2003), which deals precisely on the quality of agrarian reform settlements in Brazil, among others. Similarly, income earned from the analysis of data from the questionnaires were discussed in a comparative way, the different perspectives of consolidation, based on the operational concept (consolidation), currently adopted by Incra.
142

Investigação de interações hiperfinas em silício puro e silício NTD pela técnica de correlação angular gama-gama perturbada / Investigation of hyperfine interactions in pure silicon and NTD silicon by means of perturbed angular γ-γ correlation spectroscopy

Moacir Ribeiro Cordeiro 22 February 2007 (has links)
O presente trabalho realiza a investigação de interações hiperfinas em amostras de silício monocristalino através da técnica de Correlação Angular γ-γ Perturbada (CAP), baseada em interações hiperfinas. Para a realização das medidas, utilizou-se núcleos de prova radioativos de 111In -> 111Cd que decaem através da cascata gama 177-245keV com nível intermediário de 245keV (I = 5+/2 , Q = 0.83b, T1/2 = 84.5ns). As amostras foram confeccionadas utilizando vários métodos de inserção de núcleos de prova, possibilitando maior compreensão acerca dos impactos gerados por cada um destes métodos nas medidas CAP. As técnicas de implantação iônica, difusão e evaporação foram cuidadosamente investigadas ressaltando-se suas particularidades. Realizou-se então, um estudo acerca das concentrações de defeitos intrínsecos em função de vários processos de tratamento térmico. Finalmente, foi feita uma análise comparativa para os vários métodos de inserção dos núcleos de prova. Realizou-se, também, medidas CAP em silício monocristalino dopado com fósforo através do processo NTD. A altíssima uniformidade de dopagem associada a este método aliada à inexistência de medidas para este tipo de material ressaltam a relevância dos resultados obtidos. Estes resultados são então comparados com os resultados da literatura para amostras dopadas através de métodos convencionais apresentando-se as respectivas conclusões. / In the present work, a microscopic investigation of hyperfine interactions in single crystal silicon samples was carried out by means of Perturbed Angular γ-γ Correlation technique (PAC), which is based in hyperfine interactions. In order to achieve these measurements, it was used 111In ->111Cd radioactive probe nuclei, which decay through the well known γ cascade 177-245keV with an intermediate level of 245keV (I = 5+/2 , Q = 0.83b , T1/2 = 84.5ns). The samples were prepared using diferent probe nuclei insertion methods, making possible to increase our understanding on the impact generated by each of these techniques in PAC measurements. Ion implantation, difusion and evaporation were carefully investigated giving emphasis on its characteristics and particularities. Then, it was made a study about the concentration of intrinsic defects as function of several annealing processes. Finally, a comparative analysis was made for all these probe nuclei insertion methods. This work also accomplished PAC measurements in single crystal silicon doped with phosphorus by means of NTD method, carried out in a research nuclear reactor. The extremely high doping uniformity allied to the non-existence of previous measurements in these materials emphasize the importance of the results obtained. These results are then compared with literature results for samples doped by conventional methods presenting the respective conclusions.
143

Comparison of A*, Euclidean and Manhattan distance using Influence map in MS. Pac-Man

Ranjitkar, Hari Sagar, Karki, Sudip January 2016 (has links)
Context An influence map and potential fields are used for finding path in domain of Robotics and Gaming in AI. Various distance measures can be used to find influence maps and potential fields. However, these distance measures have not been compared yet. ObjectivesIn this paper, we have proposed a new algorithm suitable to find an optimal point in parameters space from random parameter spaces. Finally, comparisons are made among three popular distance measures to find the most efficient. Methodology For our RQ1 and RQ2, we have implemented a mix of qualitative and quantitative approach and for RQ3, we have used quantitative approach. Results A* distance measure in influence maps is more efficient compared to Euclidean and Manhattan in potential fields. Conclusions Our proposed algorithm is suitable to find optimal point and explores huge parameter space. A* distance in influence maps is highly efficient compared to Euclidean and Manhattan distance in potentials fields. Euclidean and Manhattan distance performed relatively similar whereas A* distance performed better than them in terms of score in Ms. Pac-Man (See Appendix A).
144

Development of numerical models of vertical ground heat exchangers and experimental verification : domain decomposition and state model reduction approach / Développement et vérification expérimentale de modèles numériques réduits pour la prédiction du transfert de chaleur dans les capteurs enterrés verticaux

Kim, Eui-Jong 21 March 2011 (has links)
Dans le contexte énergétique actuel, les pompes à chaleur (PAC) géothermiques sont parmi les technologies les plus performantes pour augmenter l’efficacité énergétique des bâtiments. Par contre le coût initial et l’encombrement des capteurs enterrés traditionnels peuvent être un obstacle à sa diffusion sur le marché des énergies renouvelables. Pour réduire ces coût et encombrement, une réflexion sur l’adjonction d’un système d’appoint et/ou de recharge thermique du sol aux capteurs enterrés est actuellement en cours de tests. Les outils actuels de modélisation des capteurs enterrés obtiennent en effet de bons résultats mais seulement pour un dimensionnement classique en régime permanent. Les modèles existants ne permettent donc pas de représenter correctement les dynamiques rapides des échanges entre le sol et les tubes et cela est d’autant plus vrai si l’on adjoint le système de recharge solaire. Par conséquence, cette thèse a pour objectif de développer les modèles fins et dynamiques nécessaires à l’analyse des phénomènes transitoires dans les capteurs enterrés eux-mêmes. Un maillage fin, sur les bases de la triangulation de Delaunay, est choisi pour le forage ainsi que pour le sol avoisinant. Une approche numérique en 3D (FVM + FEM) peut être obtenue sur les bases de la discrétisation spatiale du domaine. Cette approche appliquée brutalement induirait des temps de calcul très élevés et de toute façon incompatible avec les moyens informatiques ordinaires. Afin de répondre à l’ensemble de ces problèmes, différentes techniques ont été utilisées afin d’accélérer le temps de calcul: décomposition de domaine, emboîtement des pas de temps de calcul pour chaque sous-domaine, réduction des modèles d’états de chaque sous-domaine et finalement couplages temporels et spatiaux des équations de transferts de l’ensemble du problème. Ce dernier est développé particulièrement sur les bases de la méthode des éléments finis. Par ailleurs, un modèle hybride est développé en combinaison de différentes approches. Une approche numérique est adoptée pour la modélisation du puits et la modélisation des transferts de chaleur dans le sol environnant est faite par l’utilisation de solutions analytiques. Ainsi, ce modèle est implanté dans TRNSYS. Une plate-forme expérimentale comprenant trois puits verticaux couplés à une pompe à chaleur géothermique est également présentée. Les résultats expérimentaux sont comparés avec les résultats de la simulation aussi bien au niveau de la température du fluide qu’à la température à différentes profondeurs dans les puits. Le modèle développé donne des résultats très similaires avec ceux qui sont obtenus grâce à l’expérimentation même lors que les pas de temps sont très petits. Il y a des choses à améliorer dans ce modèle développé, mais cela concerne essentiellement l’accélération du temps de calcul. Nous avons constaté que les modèles que nous avons dévéloppés donnent des résultats meilleurs à pas de temps courts que les modèles classiques. Il faut donc bien préciser le domaine d’utilisation de chacun des modèles: consommation sur le long terme, stratégie de contrôle de la PAC, les transferts de chaleur à l’intérieur du puits et etc. De plus, une application du modèle dans le dimensionnement d’échangeurs ainsi que l’investigation de son impact sur le sol avoisinant est également envisagée. Finalement, la méthodologie de modélisation présentée dans ce travail pourrait être aussi utilisé pour différents types d’échangeurs, ouvrant aussi la porte à une analyse fine dans le domaine géothermique. / Ground-source heat pump systems with vertical ground heat exchangers (GHE) are gaining popularity worldwide for their higher coefficients of performance and lower CO2 emissions. However, the higher initial cost of installing the borehole GHEs is a main obstacle to spread the systems. To reduce the required total GHE length and efficiently operate the systems, various systems such as hybrid ones (e.g. solar heat injection) have recently been introduced. Accurate prediction of heat transfer in and around boreholes of such systems is crucial to avoid costly overdesigns or catastrophic failures of undersized systems as it is for typical GCHP systems. However, unlike the traditional sizing methods, it is increasingly required to take into account detailed borehole configuration and transient effects (e.g. short circuit effects between U-tubes). Many of the existing GHE models have been reviewed. Some of these models have serious limitations when it comes to transient heat transfer, particularly in the borehole itself. Accordingly, the objective of this thesis is to develop a model that is capable to accurately predict thermal behaviors of the GHEs. A precise response to input variations even in a short time-step is also expected in the model. The model also has to account for a correct temperature and flux distribution between the U-tubes and inside the borehole that seems to be important in the solar heat injection case. Considering these effects in 3D with a detailed mesh used for describing the borehole configurations is normally time-consuming. This thesis attempts to alleviate the calculation time using state model reduction techniques that use fewer modes for a fast calculation but predict similar results. Domain decomposition is also envisaged to sub-structure the domain and vary the time-step sizes. Since the decomposed domains should be coupled one another spatially as well as temporally, new coupling methods are proposed and validated particularly in the FEM. For the simulation purpose, a hybrid model (HM) is developed that combines a numerical solution, the same one as the 3D-RM but only for the borehole, and well-known analytical ones for a fast calculation. An experimental facility used for validation of the model has been built and is described. A comparison with the experimental results shows that the relatively fast transients occurring in the borehole are well predicted not only for the outlet fluid temperature but also for the grout temperatures at different depths even in very short time-steps. Even though the current version of 3D-RM is experimentally validated, it is still worth optimizing the model in terms of the computational time. Further simulations with the 3D-RM are expected to be carried out to estimate the performance of new hybrid systems and propose its appropriate sizing with correspondent thermal impacts on the ground. Finally, the development of the model 3D-RM can be an initiation to accurately model various types of GHE within an acceptable calculation time.
145

Nitrate-nitrogen sufficiency ranges in leaf petiole sap of pac choi grown with organic and conventional fertilizers

Elfar Altamimi, May January 1900 (has links)
Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Rhonda R. Janke / Petiole sap nitrate-nitrogen (NO3-N) analysis with handheld meters is a valuable tool in applying in-season nitrogen (N) for many crops. Sufficiency levels have been determined for several leafy green crops, including lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.), but not for pac choi (Brassica rapa L.). The response of pac choi to different fertilizer rates and sources [conventional and organic] has established optimal soluble N application rates and Cardy meter sufficiency ranges. Greenhouse experiments were conducted during summer and fall of 2008 in Manhattan, KS. Conventional soluble fertilizer was formulated from inorganic salts with a 4 NO3-N: 1 ammonium ratio. Phosphorus was held at 1.72mM and K at 0.83mM for all treatment levels. The organic soluble fertilizer, fish hydrolyzate (2N:1.72P:0.83K), was diluted to provide the same N levels as with conventional treatments. Both fertilizers were applied at rates of 0, 32, 75, 150, 225, 300, and 450 mg. L-1. Seedlings were transplanted and fertilizer application began at 18 days. Plants were harvested at seven weeks (five weeks post transplanting) after receiving 15 fertilizer applications during production. Samples of the most recently matured leaves were harvested weekly and analyzed for petiole sap NO3-N and leaf blade total N concentration. Leaf count, leaf length, and chlorophyll content were also measured weekly. Fresh and dry weights were determined on whole shoots and roots. Optimum yield was achieved at the 150 mg. L-1 fertility rate with both conventional and organic fertilizers. Field and high tunnel experiments were conducted during fall 2008 to validate the sufficiency ranges obtained from the greenhouse studies. Based on field and high tunnel results, sufficiency levels of NO3-N for pac choi petiole sap during weeks 2 to 3 of production were 800-1500 mg. L-1, and then dropped to 600-1000 mg. L-1 during weeks 4 through harvest for both conventional and organic fertilizers sources. These ranges could vary based on the variety of the crop, the fertility of soil, and certain environmental factors such as photoperiod, light intensity. However, we found that petiole sap nitrate always increased to the point associated with the maximum biomass, followed by a plateau where sap nitrate remained constant. This characteristic of the Cardy meter can provide the growers with a practical methodology to generate their standard curves under specific conditions to guide in-season N applications. Total N in leaf tissue showed fewer fertilizer rate effects than petiole sap NO3-N. Chlorophyll content was not useful in evaluating pac choi N status.
146

Pretreatment options for municipal wastewater reuse using membrane technology

Hatt, Juliette W. January 2012 (has links)
Increasing freshwater scarcity across the world means that wastewater reclamation is being considered as a key method in which to meet the growing demand. Evolution of water reuse schemes where high quality product is required such as for indirect potable reuse has led to the adoption in recent years of the integrated membrane scheme using a combination of microfiltration or ultrafiltration with reverse osmosis membrane. However, despite technological advancements, these membranes are still prone to fouling resulting in increased costs through cleaning or replacement. This thesis aims to look at pretreatment to reduce the fouling propensity of the microfiltration membranes via a 600m3 /d pilot plant which was commissioned to investigate indirect potable reuse. A range of pretreatments including pre-screening, pre-coagulation, powdered activated carbon and granular activated carbon were assessed based on fouling amelioration, water quality improvement and cost analysis. Results showed that ferric sulphate dosing was the most effective in terms of reducing the reversible fouling rate especially at high turbidity loads enabling higher flux to be realised leading to a small cost benefit. Activated carbon proved the most effective pretreatment in terms of organic removal and a significant reduction in the irreversible fouling rate. However, the cost involved in using this as a pretreatment is significant compared to possible cost savings through reduced requirement for chemical cleaning. This pretreatment is only viable if it obviates the need for a separate organic removal process.
147

Processus de substitution markoviens : un modèle statistique pour la linguistique / Markov Substitute Processes : a statistical model for linguistics

Mainguy, Thomas 11 December 2014 (has links)
Ce travail de thèse propose une nouvelle approche au traitement des langues naturelles. Plutôt qu'essayer d'estimer directement la probabilité d'une phrase quelconque, nous identifions des structures syntaxiques dans le langage, qui peuvent être utilisées pour modifier et créer de nouvelles phrases à partir d'un échantillon initial. L'étude des structures syntaxiques est accomplie avec des ensembles de substitution Markoviens, ensembles de chaînes de caractères qui peuvent être échangées sans affecter la distribution. Ces ensembles définissent des processus de substitution Markoviens qui modélisent l'indépendance conditionnelle de certaines chaînes vis-À-Vis de leur contexte. Ce point de vue décompose l'analyse du langage en deux parties, une phase de sélection de modèle, où les ensembles de substitution sont sélectionnés, et une phase d'estimation des paramètres, où les fréquences pour chaque ensemble sont estimées. Nous montrons que ces processus constituent des familles exponentielles quand la structure du langage est fixée. Lorsque la structure du langage est inconnue, nous proposons des méthodes pour identifier des ensembles de substitution à partir d'un échantillon, et pour estimer les paramètres de la distribution. Les ensembles de substitution ont quelques relations avec les grammaires hors-Contexte, qui peuvent être utilisées pour aider l'analyse. Nous construisons alors des dynamiques invariantes pour les processus de substitution. Elles peuvent être utilisées pour calculer l'estimateur du maximum de vraisemblance. En effet, les processus de substitution peuvent être vus comme la limite thermodynamique de la mesure invariante d'une dynamique de crossing-Over. / This thesis proposes a new approach to natural language processing. Rather than trying to estimate directly the probability distribution of a random sentence, we will detect syntactic structures in the language, which can be used to modify and create new sentences from an initial sample.The study of syntactic structures will be done using Markov substitute sets, sets of strings that can be freely substituted in any sentence without affecting the whole distribution. These sets define the notion of Markov substitute processes, modelling conditional independence of certain substrings (given by the sets) with respect to their context. This point of view splits the issue of language analysis into two parts, a model selection stage where Markov substitute sets are selected, and a parameter estimation stage where the actual frequencies for each set are estimated.We show that these substitute processes form exponential families of distributions, when the language structure (the Markov substitute sets) is fixed. On the other hand, when the language structure is unknown, we propose methods to identify Markov substitute sets from a statistical sample, and to estimate the parameters of the distribution. Markov substitute sets show some connections with context-Free grammars, that can be used to help the analysis. We then proceed to build invariant dynamics for Markov substitute processes. They can among other things be used to effectively compute the maximum likelihood estimate. Indeed, Markov substitute models can be seen as the thermodynamical limit of the invariant measure of crossing-Over dynamics.
148

Study of ZrSiO<sub>4</sub> Phase Transition Using Perturbed Angular Correlation Spectroscopy

Rambo, Matthew P. 03 March 2005 (has links)
No description available.
149

Support vector machines, generalization bounds, and transduction

Kroon, Rodney Stephen 12 1900 (has links)
Thesis (MComm)--University of Stellenbosch, 2003. / Please refer to full text for abstract.
150

Physikalische Kartierung der RT1-C/M-Region des Haupthistokompatibilitätskomplexes der Ratte / physical map of the RT1-C/M region of the major histocompatibility complex of the rat

Ioannidu, Sofia 02 November 2000 (has links)
No description available.

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