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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.
281

Calorimétrie à argon liquide et recherche de nouvelle physique via l'étude de paires de quarks top boostés dans l'expérience ATLAS au LHC / Liquid argon calorimetry and search for new physics using boosted top quarks with the ATLAS experiment at the LHC

Camincher, Clément 06 October 2017 (has links)
Le modèle standard de la physique des particules, bien qu'étant une réussite incontestable n'explique toujours pas certaines observations, ce qui pourrais indiquer la présence d'une nouvelle physique. L'expérience ATLAS cherche à mettre en évidence ces nouveaux phénomènes en analysant les collisions de protons du LHC.Le prérequis pour toute analyse est d'avoir des données de bonne qualité. La première partie de cette thèse présente donc une étude sur les bouffées de bruit cohérent présentes dans les calorimètres à argon liquide d'ATLAS. Ce bruit a été traité pour garder un haut niveau de qualité des données.La deuxième partie de cette thèse se place dans le cadre de la recherche de nouvelle physique. Une résonance est cherchée dans le spectre en masse invariante des paires de quarks top. L'étude se concentre sur le cas des quarks top boostés se désintégrant de manière électronique. Cette topologie n'ayant jusqu'à présent pas été optimisée par la collaboration ATLAS, le travail de cette thèse a consisté à définir et développer une nouvelle méthode appelée "electron-in-jet removal" permettant d'améliorer la reconstruction des quarks top dans un tel régime.Cette méthode donne accès à des électrons qui auparavant étaient rejetés. Il faut donc mesurer les facteurs correctifs à appliquer pour corriger les imperfections de la simulation de ces électrons. Des mesures préliminaires de facteurs d'échelle d'identification sur les électrons se trouvant dans un jets ont ainsi été menées. Deux méthodes sont présentées ainsi qu'une réflexion sur les perspectives à apporter à ces mesures. / The standard model of particle physics is a very predictive theory, but it still fails to explain some observations and so leads to the idea of the existence of new physics. To discover it experimentally, the ATLAS collaboration analyses the proton-proton collisions provided by the LHC.Analyses need data of good quality. Hence, the first part of this document describes a work to characterize the coherent noise bursts observed in the liquid argon calorimeters of the ATLAS experiment. Such noise has been studied and cured to ensure a high level of data quality.The second part of this thesis takes place in the context of a new physics search using top quark pairs. This study is focused on the case where boosted top quarks decay electronically. The reconstruction of top quarks in such cases was never optimized by the ATLAS collaboration. Therefore this study has lead to the definition and implementation of a new method called "electron-in-jet removal" improving significantly the top quark reconstruction in such topologies.This new method gives access to electrons that were previously removed. The correction factor applied to correct the imperfections of the simulation should then be computed for those electrons. Some preliminary measurements have been performed for the cases where the electron is within a jet. Two methods are presented as well as thoughts about future implementations.
282

Mesure de la section efficace de production électrofaible de quark top en voie S, dans l'expérience ATLAS / Single-top s channel cross-section measurement with the ALTAS detector

Monini, Caterina 12 September 2014 (has links)
Le travail présenté dans cette thèse a pour sujet la mesure du seul mécanisme de production électrofaible de quark top qui n'ait pas encore été observé au collisionneur hadronique du CERN (LHC): la voie-s. L'intérêt réside dans la confirmation des prédictions du Modèle Standard, mais le but est aussi de contraindre plusieurs scénarios de nouvelle physique à partir de la combinaison de la section efficace voie-s avec celle des autres canaux de production single top, la voie-t et Wt. Après une introduction générale sur la physique du quark top et les dispositifs expérimentaux visant à la détection et la reconstruction des objets physiques, on présente deux analyses réalisées des données de collisions proton-proton enregistrées par le détecteur ATLAS `a une énergie dans le centre de masse de 7 et 8 TeV. Etant donné que la production de quark top en voie-s est caractérisée par une tr`es faible pureté et que, en même temps, elle est défavorisée au LHC puisque elle a lieu par annihilation quark-antiquark, une technique multi variée a été appliquée dans les deux cas afin de discriminer le signal. Pour l' étude à 7 TeV, relatif à une luminosité intégrée de 4.7 $fb^{-1}$, deux classificateurs basés sur des arbres de décision boostés sont entrainés contre les événements de bruits de fond principaux; une coupure appliquée sur un des discriminateurs met en oeuvre une sélection des événements, la distribution issue de l'autre discriminateur est ensuite employée dans un fit de maximum de vraisemblance. Cela permet de d'eriver une limite supérieure sur la section efficace voie-s de 21.5 pb (14.3 pb attendu), correspondant à une portée de 0.6 déviations standard (0.8 attendu). L'analyse à 8 TeV, qui est basée sur une luminosité intégrée de 20.3 $fb^{-1}$, repose sur une strat'egie plus simple: seulement un classificateur BDT est optimisé pour isoler le signal, après une préalable sélection des événements grâce `a de simples coupures. Sa distribution discriminante est ensuite ajustée aux données selon la même approche qu' `a 7 TeV, en considérant les incertitudes systématiques et statistiques pendant la génération de pseudo expériences. La portée de la mesure étant encore inférieure à trois déviations standard (1.5 $sigma$ observé et 1.4 attendu), seule une limite `a 95% C.L. peut être établie sur la section efficace; le résultat correspond `a 15.7 pb (7.9 pb attendu). / The work reported in this thesis is aimed at measuring with the ATLAS detector theonly mechanism of top quark electroweak production which has not yet been observedat the Large Hadron Collider: the s-channel. Its interest relies in the confirmationof the Standard Model predictions but, as well, in the possibility of constraining severalnew physics scenarios when comparing the s-channel cross section with the oneof the other single top production modes (the Wt and t-channel). After a generalintroduction upon top physics and the experimental setup employed for the detectionand the reconstruction of the physics objects, we present two analyses realizedwith proton-proton collisions collected by the ATLAS detector at a center of massenergy of 7 and 8 TeV. Since the s-channel production is characterized by a verylow purity and, at the same time, is not favoured at the LHC because it proceedsvia quark-antiquark annihilation, a multivariate approach is applied in both cases todiscriminate the signal. For the 7 TeV study, based on an integrated luminosity of4.7 fb−1, two boosted decision trees classifiers are optimized against the main sourcesof background; a cut realized on one of such discriminants implements a tight eventselection, after which the second output distribution is used for a maximum likelihoodfit to the data. This allows to set an upper limit on the s-channel cross section of21.5 pb (14.3 pb expected), corresponding to a significance of 0.6 standard deviations(0.8 expected). The 8 TeV analysis, based on an integrated luminosity of 20.3 fb−1,has a simpler strategy: only one boosted decision trees classifier is trained to isolatesignal after a preliminary cut-based selection; its output distribution is then fitted tothe data with the same approach than at 7 TeV, taking into account the systematicand statistical uncertainty via the generation of pseudoexperiments. The significanceof the s-channel measurement being lower than 3 σ (1.3 standard deviation observed,1.4 expected), only a 95% C.L. limit can be set on the cross section; the result ishowever improved and corresponds to 14.6 pb (7.9 pb expected).3
283

Development of a data-driven distributed hydrological model for regional scale catchments prone to Mediterranean flash floods. Application to the Ardèche catchment, France / Développement d'un modèle hydrologique distribuée construit à partir de l'analyse des données pour la modélisation régionale des bassins Méditerranéens soumis aux crues rapides. Application au bassin versant de l’Ardèche. France

Adamovic, Marko 05 December 2014 (has links)
L'objectif scientifique de la thèse est de progresser dans la modélisation hydrologique spatiale régionale dans le contexte de crues éclairs qui représentent l'une des catastrophes naturelles les plus destructrices dans la région Méditerranéenne. L'accent est mis sur les questions de mise à l'échelle des bassins versants et la dérivation des équations et des modèles applicables aux bassins de milieu simplifiées de grande taille pour mieux décrire l'hétérogénéité du paysage et de la complexité du processus. Telles sont les questions clés pour faciliter le modèle mis en place dans le contexte de l'ensemble du bassin versant et d'essayer son application dans les bassins non jaugés trop. Pour répondre à ces questions, une modélisation hydrologique spatiale simplifiée sur les sous-bassins versants est d'abord proposé où les paramètres sont essentiellement tirées de l'information disponible (surtout cartographique). La méthode de Kirchner (WRR, 2009) qui suppose que le débit à la sortie est la seule fonction de stockage du bassin versant, est spécifiquement étudiée dans le cadre des bassins versants Méditerranéens. L'étape suivante consiste à créer un nouveau modèle hydrologique SIMPLEFLOOD distribué sur la base de « top down » méthodologie de Kirchner dans la plateforme de modélisation JAMS. Les paramètres du modèle simple sont estimés à des endroits calibrés et une régionalisation se fait en fonction de la géologie. Le bassin versant est discrétisé en sous-bassins versants d'environ 10 km2. La dernière étape consiste à procéder à un couplage de données avec le modèle hydraulique MAGE 1D développé à IRSTEA HHLY tenir compte des effets de propagation de la rivière sur les hydrogrammes simulés. Le couplage est externe, ce qui signifie que les sorties du modèle hydrologique dans le système de modélisation de JAMS deviennent les entrées du modèle MAGE hydraulique. Les sorties sont les débits qui sont transférés dans le modèle de MAGE soit comme flux latéraux (provenant des terres adjacentes) et /ou entrées d'eau locales. L'application de la thèse est le bassin versant de l'Ardèche (2388 km ²), qui est l'un des sites pilotes français pour le programme international HyMeX (cycle hydrologique dans l'expérience de la Méditerranée, http://www.hymex.org/). La thèse proposée contribue également au projet FloodScale (multi-échelle d'observation hydrométéorologique et de modélisation pour la compréhension et simulation des crues éclairs (http://floodscale.irstea.fr/). L'application de la méthodologie Kirchner (2009) montre que les résultats de simulation des débits sont bonnes pour les bassins de granit, trouvés à être caractérisée principalement par des processus excès de ruissellement et d'écoulement sous la surface de saturation. L'hypothèse simple de système dynamique fonctionne particulièrement bien dans des conditions humides (pics et les récessions sont bien modélisés). D'autre part, la performance du modèle est moins bien représentée à l'été et les périodes de sécheresse où l'évapotranspiration est large et observations de bas-débits sont inexactes. Dans le bassin versant de l'Ardèche, les précipitations simulées correspondent bien à de stations de jaugeage observés et données de réanalyse SAFRAN pendant les périodes de non-végétation. Le modèle doit encore être amélioré pour inclure une représentation plus précise de l'évapotranspiration réelle, mais fournit un résumé satisfaisant du fonctionnement du bassin versant pendant les périodes humides et d'hiver. Le couplage du modèle hydrologique obtenue avec le modèle hydraulique MAGE 1D fournit des résultats satisfaisants mais les résultats sont si réciproques comme dans le cas du modèle hydrologique ou une équation d'onde cinématique simple pour le routage des flux existe. On peut dire que dans les situations ou débordement de la rivière est significative, le couplage serai crucial. / The scientific objective of the thesis is to progress in regional spatial hydrological modeling in the context of flash floods that represent one of the most destructive natural hazards in the Mediterranean region. Emphasis is put on catchment scaling issues and derivation of simplified equations and models applicable to basins of medium to large size to best describe landscape heterogeneity and process complexity. These are the key issues in facilitating the model set up in the context of the whole catchment and trying its application in ungauged catchments too. To address these issues, a simplified spatial hydrological modeling over sub-catchments is first proposed where parameters are essentially derived from available information (cartographic utmost). For this purpose, the Kirchner (WRR, 2009) method that assumes that discharge at the outlet is only a function of catchment storage is specifically studied in the context of Mediterranean catchments. The next step is to create a new distributed hydrological model based on the data driven methodology of Kirchner within the JAMS modeling framework. The parameters of the simple model are estimated at the gauged locations and a regionalization is done according to geology. The catchment is discretized into sub-catchments of about 10 km2. The final step is to proceed with data coupling with the MAGE 1D hydraulic model developed at HHLY to consider river propagation effects on the simulated hydrographs. The coupling is external, meaning that outputs from the hydrological model in JAMS modeling system become inputs to the hydraulic model MAGE. Outputs are discharge rates in the reach network that are transferred into the MAGE model as either lateral flows (coming from adjacent land) and/or local inflows. The case study of the thesis is the Ardèche catchment (2388 km²), which is one of the French pilot sites for the HyMeX international program (Hydrological Cycle in the Mediterranean Experiment, http://www.hymex.org/). The proposed thesis also contributes to the FloodScale project (Multi-scale hydrometeorological observation and modeling for flash floods understanding and simulation, http://floodscale.irstea.fr/ ). The application of the Kirchner (2009) methodology shows that resulting discharge simulation results are good for granite catchments, found to be predominantly characterized by saturation excess runoff and sub-surface flow processes. The simple dynamical system hypothesis works especially well in wet conditions (peaks and recessions are well modeled). On the other hand, poor model performance is associated with summer and dry periods when evapotranspiration is high and operational low-flow discharge observations are inaccurate. In the Ardèche catchment, inferred precipitation rates agree well in timing and amount with observed gauging stations and SAFRAN data reanalysis during the non-vegetation periods. The model should further be improved to include a more accurate representation of actual evapotranspiration, but provides a satisfying summary of the catchment functioning during wet and winter periods. The coupling of the resulting hydrological model with the MAGE 1D hydraulic model provides satisfying results. However, the results show that the timing and magnitude of simulated discharge with coupled model is as good as by the hydrological model with a simple kinematic wave equation for flow routing. We argue that in situations when there is a significant overflow in the floodplain the interest of the coupling with the hydraulic model becomes crucial.
284

O que controla o crescimento do Fitopl?ncton em lagoas costeiras tropicais? um modelo para a lagoa de Extremoz (RN)

Silva, Andrievisk Gaudencio Pereira e 26 March 2014 (has links)
Made available in DSpace on 2014-12-17T15:03:33Z (GMT). No. of bitstreams: 1 AndrieviskGPS_DISSERT.pdf: 1181960 bytes, checksum: 3416b1e3bd91514fea43dc2c94f227dc (MD5) Previous issue date: 2014-03-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The phytoplankton growth is dependent of several abiotic (nutrients, temperature) and biotic (predation by zooplankton) variables. In this work, a mathematical model was developed in Stella software to understand the planktonic dynamics of Extremoz Lagoon (RN) and to simulate scenarios of different environmental conditions. Data were collected monthly at two points of the lagoon. The state variables are phytoplankton and zooplankton and forcing variables are nitrogen, phosphorus and temperature. The results show that: a) the model are well coupled, especially when some constants assume different values; b) simulated nutrient concentrations reduction decreases phytoplankton biomass, but the increase of nutrients does not stimulate the growth; c) changes in the temperature does not change the phytoplankton biomass; d) changes in zooplankton biomass affect directly and reduces the phytoplankton, indicating a topdown control mechanism; e) changes in the nutrient concentration modified the biomass of zooplankton suggesting a rapid flow of energy between nutrients, phytoplankton and zooplankton and a ecosystem likely arranged in an inverted pyramid (higher concentration of zooplankton than phytoplankton) / O crescimento fitoplanct?nico ? dependente de uma s?rie de vari?veis abi?ticas (nutrientes, temperatura, luz) e bi?ticas (preda??o por zoopl?ncton e outros fitoplanct?fagos, bact?rias que provocam lise celular no fitopl?ncton). Neste trabalho, um modelo de compartimentos foi desenvolvido no software Stella para entender a din?mica planct?nica da Lagoa de Extremoz (RN) e simular diferentes cen?rios de altera??es em importantes vari?veis ambientais como fitopl?ncton e zoopl?ncton. As medi??es foram realizadas mensalmente em dois pontos da lagoa. As vari?veis de estado s?o fitopl?ncton e zoopl?ncton e as for?antes s?o nitrog?nio, f?sforo e temperatura. Os resultados mostram que: a) o modelo se ajusta bem aos dados, especialmente quando algumas constantes assumem diferentes valores; b) simula??es de redu??es das concentra??es de nutrientes diminuem a biomassa fitoplanct?nica, mas o aumento dos nutrientes n?o favorece o crescimento; c) altera??es na temperatura n?o modificam a biomassa fitoplanct?nica; d) modifica??es na biomassa de zoopl?ncton afetam diretamente e consideravelmente o fitopl?ncton, indicando um mecanismo de controle top-down; e) altera??es nas concentra??es de nutrientes modificam a biomassa do zoopl?ncton sugerindo um r?pido fluxo de energia entre nutrientes, fito e zoopl?ncton e um prov?vel ecossistema arranjado em pir?mide invertida (maior biomassa de zoopl?ncton do que fitopl?ncton)
285

Projeto e avaliação de algoritmos paralelos para sistemas Multicore e Manycore aplicados no processamento de documentos / Design and evaluation of parallel algorithms for Multicore and Manycore systems applied on document processing

Freitas, Mateus Ferreira e 30 August 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-02T15:28:01Z No. of bitstreams: 2 Dissertação - Mateus Ferreira e Freitas - 2017.pdf: 4269845 bytes, checksum: e84e69d8747a21125170793812384a98 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-02T15:30:07Z (GMT) No. of bitstreams: 2 Dissertação - Mateus Ferreira e Freitas - 2017.pdf: 4269845 bytes, checksum: e84e69d8747a21125170793812384a98 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-02T15:30:07Z (GMT). No. of bitstreams: 2 Dissertação - Mateus Ferreira e Freitas - 2017.pdf: 4269845 bytes, checksum: e84e69d8747a21125170793812384a98 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-30 / Several applications process documents in different ways, aiming to filter, organize or learn with them. Nowadays, a great computational power is necessary in order to do that efficiently, due to the large and increasing number of documents. Usually, documents are independent of each other, which facilitates the use of parallelism to speed up this processing. This work explores three problems: active learning, learning to rank (L2R) and top-k search. Using the parallelism on multicore CPUs and manycore GPUs (Graphics Processing Unit), parallel algorithms were proposed and evaluated for each problem, and implemented with the OpenMP and CUDA APIs. For the active learning problem a multicore algorithm was proposed, which obtained 10.8x of speedup in the best case with 12 threads. The proposed manycore version obtained 128x of speedup over the serial version, and a solution with 4 GPUs achieved 3.5x of speedup over 1 GPU. For the L2R problem a manycore algorithm was proposed, which follows a thread-block approach using the concept of Combinadic, and uses a cache with fingerprint to speed up the processing. The best case speedups were 508x over the serial, 9x over a GPU baseline, and 4x over our solution when using 4 GPUs. When comparing with a version without combinadic, the speedup over it was 4.4x with both versions using 1 GPU and 3.9x with 4. These solutions used bitmap structures to speed up the association rules creation. In the top-k search a serial and multicore solutions were implemented from a state of the art manycore algorithm for exact searches. These implementations served as baselines for our extension of this algorithm, which includes the use of multi-GPU, group searches and an intra-block load balancing. The speedups were 2.7x over the original algorithm, 17x over the serial, 4x over the multicore, and 4x over our version when using 4 GPUs. / Diversas aplicações processam documentos de diferentes maneiras, visando filtrá-los, organizá-los ou aprender com eles. Atualmente, é necessário um grande poder computacional para que isso seja feito eficientemente, devido ao número grande e crescente de documentos. Geralmente os documentos são independentes entre si, o que facilita o uso de paralelismo para acelerar esse processamento. Este trabalho explora três problemas: aprendizado ativo, learning to rank (L2R) e busca top-k. Usando o paralelismo em CPUs multicore e GPUs (Graphics Processing Unit) manycore, algoritmos paralelos foram propostos e avaliados para cada problema, e implementados com as APIs OpenMP e CUDA. Para problema de aprendizado ativo foi proposto um algoritmo multicore, que obteve speedup de 10,8x no melhor caso com 12 threads. A versão manycore proposta obteve speedup de 128x em relação ao serial, e uma solução com 4 GPUs atingiu 3,5x de speedup sobre 1 GPU. Para o problema de L2R foi proposto um algoritmo manycore, que segue uma abordagem por bloco de threads} usando o conceito de Combinadic, e usa uma cache} com fingerprint para acelerar o processamento. Os speedups nos melhores casos foram de 508x sobre o serial, 9x sobre uma baseline em GPU, e 4x sobre nossa solução com 1 GPU ao usar 4 GPUs. Ao comparar com uma versão sem o combinadic, o speedup sobre ela foi de 4,4x com ambas versões usando 1 GPU e 3,9x usando 4. Estas soluções usaram estruturas de mapa de bits para acelerar a criação de regras de associação. Na busca top-k foram implementadas uma solução serial e uma multicore de um algoritmo manycore estado da arte para buscas exatas. Estas implementações serviram de baseline para nossa extensão desse algoritmo, que inclui o uso de multi-GPU, buscas em grupos e um balanceamento de carga intra-bloco. Os speedups obtidos foram de 2,7x sobre o algoritmo original, 17x sobre o serial, 4x sobre o multicore, e 4x sobre nossa versão ao usar 4 GPUs.
286

Protease em dietas contendo farinhas de origem animal para frangos de corte / Protease in diets containing animal meal for broilers

Carvalho, Deborah Pereira 11 March 2016 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-09-15T17:16:01Z No. of bitstreams: 2 Dissertação - Deborah Pereira Carvalho - 2016.pdf: 1291033 bytes, checksum: 11909a32b04cb17d98b30025fea8cce2 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-16T12:17:36Z (GMT) No. of bitstreams: 2 Dissertação - Deborah Pereira Carvalho - 2016.pdf: 1291033 bytes, checksum: 11909a32b04cb17d98b30025fea8cce2 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-16T12:17:36Z (GMT). No. of bitstreams: 2 Dissertação - Deborah Pereira Carvalho - 2016.pdf: 1291033 bytes, checksum: 11909a32b04cb17d98b30025fea8cce2 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-11 / Research with use of exogenous enzymes in feed for broiler, has shown its advantages in improving the digestibility and nutrient availability for birds, resulting in better performance. The objective of this study was to evaluate the effect of adding "on the top" the enzyme protease 0.05% (Cybenza DP 100) in diets for broilers containing animal meal. Two experiments were conducted divided into 4 treatments each experiment. In both experiments were using the same treatments, the treatments offered were: T1 - corn-based feed and soybean meal, T2 - corn-based feed and soybean meal with addition of protease, T3 - based feed corn and soybean meal with addition of meat, feathers and viscera, T4 - corn-based feed and soybean meal with addition of meat, feathers and viscera, with the addition of protease. The "experiment 1" was carried out with 320 chicks Cobb500 strain of 1 to 21 days. The experimental design was completely randomized, divided into batteries, with 4 treatments and 8 repetitions each containing 10 broiler per cage. The variables analyzed were: digestibility and performance variables. The "Experiment 2" was carried out with 720 chicks Cobb500 strain of 1 to 42 days. The experimental design was completely randomized, divided into box with 4 treatments and 6 repetitions each containing 30 broiler per box. The analyzed variables were: performance and Biometry of the gastrointestinal tract organs and the intestines and bowel. In all treatments the data were subjected to analysis of variance, and means were compared by Tukey test at 5% significance. In the " experiment 1 " it was observed that supplementation of the enzyme protease improved the feed conversion only in the pre- initial stage , but proved advantageous to use also in the initial phase , because even with the reduction in nutrient levels the results did not differ . In the " second experiment " it was observed that the use of animal meal for broilers from 1 to 21 days of age proved advantageous , since treatments with animal meal in their composition showed better weight gain and lower feed intake . The protease enzyme supplementation improved viability. / Pesquisas com a utilização de enzimas exógenas na alimentação de frangos de corte, tem evidenciado as suas vantagens em melhorar a digestibilidade e disponibilidade de nutrientes para os frangos, resultando em melhor desempenho. Objetivou-se com o presente trabalho avaliar o efeito da adição “on the top” da enzima protease 0,05% (Cybenza DP 100) em dietas para frangos de corte contendo farinhas de origem animal. Foram conduzidos dois experimentos divididos em 4 tratamentos cada experimento. Em ambos os experimentos foram utilizando os mesmos tratamentos, os tratamentos oferecidos foram: T1 - ração à base de milho e farelo de soja, T2 - ração à base de milho e farelo de soja, com adição de protease, T3 - ração à base de milho e farelo de soja com inclusão de farinha de carne, penas e vísceras, T4 - ração à base de milho e farelo de soja com inclusão de farinha de carne, penas e vísceras, com adição de protease. O “experimento 1” foi realizado com 320 pintos da linhagem Cobb500 de 1 a 21 dias. O delineamento experimental foi inteiramente casualizado, dividido em baterias, com 4 tratamentos e 8 repetições cada, contendo 10 frangos por gaiola. As variáveis analisadas foram: digestibilidade e variáveis de desempenho. O “experimento 2” foi realizado com 720 pintos da linhagem Cobb500 de 1 a 42 dias. O delineamento experimental adotado foi inteiramente casualizado, dividido em box, com 4 tratamentos e 6 repetições cada, contendo 30 frangos por box. As Variáveis analisadas foram: desempenho e Biometria de órgãos do trato gastrointestinal e do intestino e do intestino. Em todos os tratamentos os dados foram submetidos a análise de variância, e as médias foram comparadas pelo teste de Tukey a 5% de significância. No “experimento 1” foi observado que a suplementação da enzima protease melhorou a conversão alimentar apenas na fase pré-inicial, porém se mostrou vantajoso a sua utilização também na fase inicial, pois mesmo com a redução dos níveis nutricionais os resultados não diferiram entre si. No “experimento 2” foi observado que a utilização da farinha de origem animal para frangos de corte de 1 a 21 dias de idade se mostrou vantajosa, uma vez que os tratamentos que receberam farinhas de origem animal em sua composição apresentaram um melhor ganho de peso e menor consumo de ração. A suplementação da enzima protease melhorou a viabilidade.
287

Projeto de um modulador sigma-delta de baixo consumo para sinais de áudio / Low power audio sigma delta modulator design

Heiner Grover Alarcón Cubas 23 May 2013 (has links)
Este trabalho descreve o projeto de um modulador Analógico-Digital (A/D) Sigma-Delta de 16 bits (98 dB de SNR) de baixo consumo em tecnologia CMOS para a aquisição de sinais de áudio. Para projetar o modulador foi utilizada a metodologia top down, a qual consiste em projetar desde o nível de sistema até os blocos básicos em nível de transistores. O sistema foi analizado e projetado utilizando equacões e modelos comportamentais para obter as especificações de cada bloco do modulador. Considerando um baixo consumo de potência foi escolhida a topologia CIFF (do inglês Chain of Integrator with FeedForward) de terceira ordem e quatro bits implementado com capacitores chaveados. O modulador projetado é composto por três integradores chaveados, um somador analógico, um weigthed DAC e um quantizador de quatro bits. A técnica de Chopper é incluida no modulador para diminuir o ruído Flicker na entrada do modulador. Os blocos de maior consumo dentro do modulador são as OTAs. Por esta razão eles são projetados utilizando a metodologia gm/ID reduzindo assim o consumo de potência. O projeto foi realizado na tecnologia IBM 0,18 \'mü\'m sendo utilizado o simulador spectre do Cadence. O modulador Sigma-Delta atinge um SNR de 98 dB para uma banda de 20 kHz e um consumo de potência de 2,4 mW para uma fonte de alimentação de 1,8 V. / This work describes the design of a 16 bits low power Sigma-Delta modulator (98 dB SNR) in a CMOS technology for the acquisition of audio signals. To design the modulator it was used the top-down methodology, which consists on the design from system level to the transistor-level basic blocks. The system was analyzed and designed using behavioral models and equations to obtain the specifications of each block of the modulator. Considering a low power consumption it was chosen a third-order four bits CIFF topology (Chain Integrator with feedforward) implemented with switched capacitors. The modulator is composed by three integrators, one analog adder, one weigthed DAC and one four bit quantizer. The Chopper technique is included in the modulator to reduce the Flicker noise at the input of the modulator. The blocks of higher consumption within the modulator are the OTAs. Hence, they was designed using the methodology gm/ID to reduce power consumption. It was designed on the 0.18 \'mü\'m IBM technology and using the Cadence Spectre simulator. The Sigma-Delta modulator achieves a SNR of 98 dB for a bandwidth of 20 kHz and a power consumption of 2.4 mW with a 1.8 V power supply.
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Co-ocorrência, interações tróficas e distribuição potencial da onça-pintada (Panthera onca) no bioma Amazônia / Co-occurrence, trophic interactions and potential distribution of jaguar (Panthera onca) in the Amazon biome

Francesca Belem Lopes Palmeira 27 May 2015 (has links)
Predadores de topo desempenham um papel importante na manutenção dos sistemas em que eles ocorrem porque influenciam diretamente a estrutura e a dinâmica de comunidades. Desta forma, este estudo descreveu alguns mecanismos de co-ocorrência espaço-temporal entre a onça-pintada (Panthera onca) e duas espécies de mesopredadores (Puma concolor e Leopardus pardalis), o seu controle top-down na comunidade de mamíferos e os requerimentos ambientais que determinam a sua distribuição no bioma Amazônia. Para as análises de co-ocorrência espaço-temporal foram utilizados o modelo de ocupação e a densidade de Kernel utilizando os registros de armadilhamento fotográfico (2008-2011). Para descrever o controle top-down foi elaborada uma rede trófica utilizando os itens alimentares consumidos pelas espécies e disponíveis na literatura (1983-2014). Para indicar quais as áreas mais adequadas foi utilizado o modelo de distribuição de espécies utilizando as localizações geográficas de ocorrência da espécie que foram compiladas de três diferentes bases de dados (2000-2013). A ocorrência das duas espécies de mesopredadores não foi diferente nos sítios com e sem a onça-pintada nas quatro temporadas de amostragem. A probabilidade de detecção da jaguatirica foi maior nos sítios com a presença da onça-pintada em apenas uma temporada de amostragem. A sobreposição no período de atividade das espécies de mesopredadores com a onça-pintada foi baixa, com cerca de 55% de sobreposição. Também ocorreu uma mudança razoável no período de atividade das espécies entre as temporadas de amostragem, com mínima de 32% e máxima de 56% de sobreposição. As maiores diferenças na detecção e na sobreposição temporal ocorreram na terceira temporada quando teve o maior número de capturas e recapturas da onça-pintada. A rede trófica apresentou seis níveis e grande riqueza de espécies e densidade de interações. Após a remoção da onça-pintada, houve a perda de um nível trófico e de aproximadamente 20% de interações. Quando comparada a distribuição atual da onça-pintada com a histórica, foi possível constatar a perda de espaço ambiental em áreas mais frias (< 6,3 °C), mais secas (< 288 mm), mais úmidas (> 7517 mm) e com maior elevação (> 3597 m). O modelo de distribuição também indicou que muitas áreas potenciais estão disponíveis à ocorrência da onça-pintada e que algumas merecem atenção, especialmente, nas porções leste e sul da Amazônia onde a espécie corre maior risco de desaparecimento local devido à antropização acelerada. Este estudo forneceu significativa contribuição para a compreensão da população de onça-pintada na Amazônia, bioma que ainda possui a maior lacuna de conhecimento sobre a biologia e ecologia da espécie. Demonstrou o efeito da sua presença na detectabilidade e no período de atividade de outras espécies. Também demonstrou seu papel ecológico como predador de topo exclusivo porque foi a única espécie que predou todas as outras de níveis tróficos inferiores. Descreveu o espaço ambiental originalmente ocupado (distribuição histórica) e o perdido (distribuição atual). Indicou as áreas mais adequadas à sua ocorrência e aquelas potenciais ao seu desaparecimento. / Apex predators play an important role in the maintenance of systems in which occur because they directly influence the structure and dynamics of communities Thus, this thesis aims to describe some of the mechanisms of spatio-temporal co-occurrence between the jaguar (Panthera onca) and mesopredators (Puma concolor and Leopardus pardalis), their top-down control on the community and environmental requirements that determine their distribution. To the analyses of spatio-temporal co-occurrence were used the occupancy model and the Kernel density with records derived from camera trapping (2008-2011). To the analysis of trophic networks was used a foodweb model with prey spectra of felids compiled from the available literature (1983-2014). To indicate the most suitable areas to its occurrence was used a species distribution model with geographic location of the species compiled from three different databases. The occupation of the two species of mesopredators was not different among sites with and without jaguar. The probability of detection was different for ocelot, with higher detection on sites with than without jaguar. The overlap in the activity pattern among jaguar and mesopredators was low, with approximately 55% of overlapping. Also there was a reasonable change in the overlap between sampling seasons, with a minimum of 32% and maximum of 56% of the difference in the activity pattern. The differences in the detection and temporal overlap occurred in the third season when occurred the highest number of jaguar captures and recaptures. The trophic network presented six levels and, a high species richness and links density. After removal of the jaguar, a trophic level and approximately 20% of links were lost. When compared historical and current distributions, the loss of environmental space occurred in areas colder (< 6.3 ° C), drier (< 288 mm), wetter (> 7517 mm) and at higher elevation (> 3597 m). The distribution model also indicated that there is many potential suitable areas available to the jaguar occurrence and, some of them deserve attention, particularly, in eastern and southern portions of Amazonia where the species is most at risk of local extinction. This study provided a significant contribution to the knowledge of the population of jaguar in the Amazon biome which still has the largest gap of information on the biology and ecology of the species. It demonstrated the effect of the presence of the species in the detectability and the activity pattern of others. Also, it demonstrated their ecological role as an apex predator exclusive because it was the only one that ate all other species of lower trophic levels. It described the environmental space originally occupied (historical distribution) and lost (current distribution). It indicated potential suitable areas to its occurrence and threatened areas to its disappearance.
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Integração das estratégias de sustentabilidade: \"top-down\" e \"bottomup\" como ferramentas de aprendizagem para a alfabetização ecológica no Ensino Médio / Integration of sustainability strategies: \"top-down\" and \"bottom-up\" as learning tools for ecological literacy in high school

Tainá Gouvêa Galvão Silva 03 August 2018 (has links)
O desenvolvimento sustentável no final do século XX surgiu para expressar preocupações com graves problemas que causam riscos a vida no planeta. O uso do planeta de forma sustentável exigirá diferentes estratégias de sustentabilidade. Neste sentido têm-se as estratégias que abordam o nível mais elevado do ecossistema referidas como Top-down e as estratégias que abordam componentes locais ou regionais referidas como bottom-up. A escola traz essa compreensão nos conceitos e fenômenos ecológicos. No entanto, a compreensão dessas abordagens com apoio interdisciplinar faz com que o aluno entenda os fenômenos ecológicos de forma mais crítica. Assim, para um aprendizado motivador, o professor pode utilizar como recurso didático além dos espaços formais de educação também espaços não formais de educação, ou seja, aulas de campo em ambientes naturais. Com o intuito de promover no ensino de ecologia a alfabetização ecológica dos alunos no Ensino Médio, este trabalho elaborou uma proposta didática com apoio interdisciplinar (Biologia, Língua Portuguesa e Geografia) e com ênfase nas estratégias Top-down e bottom-up abordadas tanto em espaços formais quanto não formais de educação. O método de ensino em espaço formal de educação apesar de estar estruturado didaticamente para abranger a ecologia não se apresentou motivadora ao aluno e muitos dos conceitos e fenômenos ecológicos não foram assimilados por eles. Em contrapartida, a integração interdisciplinar em associação com as estratégias de Top-down e bottom-up em espaços não formais de educação foi motivadora para o aluno melhorando o seu desempenho com relação à assimilação dos conceitos e fenômenos biológicos promovendo a alfabetização ecológica dos alunos. Espera-se com esse trabalho ter contribuído para o ensino e aprendizagem do tema sustentabilidade através da promoção da alfabetização ecológica dos alunos de Biologia no Ensino Médio em escolas públicas com a formação de cidadãos mais conscientes e críticos em assuntos ambientais. / Sustainable development in the late 20th century has emerged to express concerns about serious life-threatening problems on the planet. The use of the planet in a sustainable way will require different sustainability strategies. In this sense we have the strategies that approach the highest level of the ecosystem referred to as \"top-down\" and the strategies that approach local or regional components referred to as \"bottom-up\". The school brings this understanding into concepts and ecological phenomena. However, understanding these approaches with interdisciplinary support makes the student understand ecological phenomena more critically. Thus, for a motivating learning, the teacher can use as a didactic resource beyond the formal spaces of education also non-formal spaces of education, that is, field lessons in natural environments. In order to promote ecological literacy among students in high school, this work elaborated a didactic proposal with interdisciplinary support (Biology, Portuguese Language and Geography) and with emphasis on top-down and bottom-up strategies addressed in both formal and non-formal education settings. The method of teaching in formal educational space despite being structured to cover ecology did not present itself as motivating to the student and many concepts and ecological phenomena were not assimilated by them. In contrast, interdisciplinary integration in association with top-down and bottom-up strategies in non-formal education spaces was motivating for the student to improve his performance in relation to the assimilation of concepts and biological phenomena by promoting literacy of the students. It is hoped that this work contributed to the teaching and learning of the sustainability theme through the promotion of the ecological literacy of Biology students in High School in public schools with the formation of citizens more conscious and critical in environmental issues.
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Tamanhos pictóricos percebidos sobre gradientes de textura desenhados e fotografados após exposições breves / Pictorial size perceived under line-drawing and photographed texture gradient after brief exposures

Leonardo Gomes Bernardino 11 September 2012 (has links)
O presente estudo teve por objetivo investigar a dinâmica temporal da percepção de tamanho de objetos inseridos em gradientes de textura, provenientes de desenho gerado computacionalmente (gradiente de perspectiva) e de fotografia com elementos naturais (gradiente fotografado). Além disso, verificou-se a ocorrência e padrão dos movimentos oculares nestas condições. Para isso, foram realizados 2 experimentos. No primeiro experimento, dois círculos negros eram apresentados no meridiano vertical e a tarefa dos 96 participantes foi indicar em qual parte do campo visual, superior ou inferior, foi apresentado o maior círculo. Usando o método das escadas duplas, estes círculos eram apresentados brevemente (50, 100, 150 ou 200 ms) em três condições de fundos de tela (sem textura, gradiente de perspectiva ou gradiente fotografado). Foram calculados a inclinação da função psicométrica e o ponto de igualdade subjetivo (PIS) como medidas da sensibilidade discriminativa e da distorção perceptiva, respectivamente. Os resultados mostraram que os participantes discriminaram melhor o tamanho dos estímulos à medida que o tempo de exposição aumentava, independentemente do gradiente de textura. A análise do PIS revelou que há uma forte distorção do tamanho aos 100 ms para o gradiente de perspectiva e aos 150 ms para o gradiente fotografado. No segundo experimento, 24 participantes realizaram uma tarefa semelhante ao do primeiro experimento e utilizou-se um eye tracker para registrar o movimento ocular. Os resultados mostraram que, em apresentações de 150 e 200 ms, os movimentos oculares ocorreram em menos de 10% das tentativas em todos os fundos de tela. Isto indica que a redução das distorções de tamanho após os 100 ms observada no primeiro experimento não é explicada completamente pela alocação da atenção. Tomados em conjunto, estes resultados sugerem que o processamento e integração das informações de tamanho e profundidade são mediados principalmente por mecanismos bottom-up. Ademais, em uma condição de menor restrição temporal (1500 ms), a presença de informações de profundidade afetou a dimensão espacial das fixações e sacadas, mas não a dimensão temporal. Os participantes olharam preferencialmente para o estímulo apresentado no campo visual superior, o que indica que a atenção foi alocada às posições de maior profundidade. Os resultados também indicaram que os estímulos maiores capturaram tanto a atenção transitória quanto a atenção sustentada. Assim, este estudo permitiu um maior conhecimento sobre os mecanismos perceptivos e atentivos envolvidos no processamento das informações de tamanho e de profundidade. / This study aimed to investigate the temporal dynamics of object size perception under texture gradients from line-drawing (perspective gradient) and photograph with natural elements (photographed gradient). Additionally, it was analyzed the occurrence and the pattern of eye movements in these conditions. For this, we carried out 2 experiments. In the first experiment, two black circles were displayed in the vertical meridian and 96 participants reported whether the bigger one was presented at the lower or upper visual field. By using double staircase psychophysics method, these circles were briefly presented (50, 100, 150 or 200 ms) in three background conditions (no texture, perspective gradient or photographed gradient). The slope of the psychometric function and the points of subjectivity equality (PSE) were calculated and used as discrimination sensitivity and size distortion measures, respectively. The results showed a greater sensitivity to size discrimination as exposure time increased, regardless the texture gradient. The analysis of PSE indicated greater size distortions in perspective gradient at 100 ms and in photographed gradient at 150 ms. In the second experiment, 24 participants performed a task similar to that in Experiment 1 while an eye tracker recorded their eye-movements. The results showed that, at 150 and 200 ms, eye movements occurred in less than 10% of trials in all backgrounds. It indicates that the size distortion reduction after 100 ms observed in the first experiment cannot be fully explained by attention allocation. Taken together, these results suggest that the process and integration of size and depth information are mainly mediated by bottom-up mechanism. Moreover, in a less time constrain condition (1500 ms), depth cues affected the spatial measures of fixations and saccades, but not the temporal ones. The participants looked more frequently at the stimulus on the upper visual field, indicating that attention has been allocated to positions of greater depth. The results also indicated that large stimulus capture both transient and sustained attention. Thus, this study provides a better understanding of perceptual and attentive mechanisms involved in size and depth process.

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