Made available in DSpace on 2016-08-15T20:31:17Z (GMT). No. of bitstreams: 1 RafsonVS_DISSERT.pdf: 2368957 bytes, checksum: 5b409a2aba52dec3fb159116952b1a20 (MD5) Previous issue date: 2014-03-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The construction of reservoirs has been adopted as a strategic measure to overcome water shortages and cope with the increase of the multiple uses of this resource. Despite its social importance, the impounding of a lotic ecosystem tends to break possible longitudinal gradients, resulting in biotic and abiotic change both downstream and upstream of the reservoir. In this context, this work sought: (i) to describe the morphometric parameters of the Santa Cruz and Umari reservoirs in the semi-arid region of Rio Grande do Norte; (ii) to spatially and temporally assess the limnological characteristics of these water reservoirs. Bathymetric surveying was carried out in December 2012, with the aid of an ecobathymeter enhanced via DGPS, utilizing horizontal WGS 84 datum and the UTM coordinate system. Four samplings were extracted from the surface, the center and the bottom of the water column (integrated samples) in May, August and November 2012 and February 2013, so that limnological variables could be assessed. With the aid of a multiparameter probe, the following variables were measured in loco: pH, water temperature, electrical conductivity, total dissolved solids, turbidity and dissolved oxygen, and, via utilization of the Secchi disk, water transparence. In the Laboratory of Limnology and Water Quality of the Universidade Federal Rural do Semi-Árido, the concentration of total N, total P, ammoniacal nitrogen, nitrite N, nitrate N and Chlorophyll a was measured. Regression analyses were conducted so as to identify possible relationships between the limnological variables and the distance from the dam, and Principal Component Analyses were carried out in order to observe a spatial pattern of the points sampled during the temporal variation and gather the data concerning the sampling stations (longitudinal variation) and the collections (temporal variation). Bathymetry in Santa Cruz was based on a total of 35.971 point pairs (depth and location) and in Umari, on a total of 26.575. The Santa Cruz reservoir was verified to have a maximum length of 15.984m, average water depth of 13m and maximum depth of 38m. As for the Umari reservoir, maximum length, average depth and maximum depth were confirmed to be 14.227m, 8m and 28m, respectively. In what concerns the storage volume, accentuated differences between the two reservoirs were recorded: 295.858.761m3 in Santa Cruz and 114.866.034m3 in Umari. Despite bearing a smaller volume, Umari presented a larger perimeter area (110.887,26 m). Both reservoirs showed a shallow relative depth which could lead to thermal instability and, consequently, a mixture of the water masses. The results of the PCA showed a spatial pattern in which, as the water ran closer to the influence zone of affluent rivers, there were higher figures of temperature, electrical conductivity, turbidity, total dissolved solids, total P, total N, and Chlorophyll a. However, it could not be verified, in either reservoir, a clear pattern of temporal variation, likely due to the low rainfall during the entire period of sampling. Finally, the reservoirs proved to be adequate for various uses, abiding to the standards set by the CONAMA resolution nº 357/2005, the average concentrations of limnological variables being considered acceptable for Class 1, with the exception of the concentration of total P in the reservoir of Santa Cruz, which was considered acceptable for Class 2. It was concluded that the classic concept of longitudinal compartmentalization with three evident zones (fluvial, transition and lake) did not apply to the reservoirs in this study; therefore, it was only possible to identify partial compartmentalization: the lake zone, accounting for the larger part of both reservoirs and bearing oligotrophic characteristics, and a reduced fluvial zone, varying between mesotrophic and eutrotrophic / A construção dos reservatórios vem sendo uma medida estratégica adotada para suprir a escassez de água e atender ao aumento dos usos múltiplos. Apesar de sua importância social, o represamento de um ecossistema lótico tende a romper possíveis gradientes longitudinais, produzindo alterações bióticas e abióticas tanto a jusante quanto a montante do reservatório. Neste contexto, o presente trabalho objetivou: (i) descrever parâmetros morfométricos dos reservatórios Santa Cruz e Umari, localizados no semiárido do Rio Grande do Norte; (ii) avaliar temporalmente e espacialmente as características limnológicas desses reservatórios. O levantamento batimétrico foi realizado em dezembro de 2012, com auxílio de um ecobatímetro acoplado a DGPS, utilizando datum horizontal WGS 84 e sistema de coordenadas em UTM. Já a avaliação das variáveis limnológicas foi realizada nos meses de maio, agosto e novembro de 2012 e fevereiro de 2013, através de quatro coletas na superfície, no meio e no fundo da coluna d água (amostras integralizadas). Com uma sonda multiparâmetros foram mensuradas in loco as seguintes variáveis: pH, temperatura da água, condutividade elétrica (CE), sólidos totais dissolvidos (STD), turbidez (TURB) e oxigênio dissolvido (OD), e por meio do disco de Secchi a transparência da água. No Laboratório de Limnologia e Qualidade de Água da Universidade Federal Rural do Semiárido foram determinadas as concentrações de N-total, P-total, N-amoniacal, N-nitrito, N-nitrato e clorofila a. Foi aplicada a análise de regressão no intuito de identificar possíveis relações entre as variáveis limnológica com a distância da barragem e a Análise dos Componentes Principais (ACP) no intuito de observar um padrão de variação espacial e temporal. A batimetria em Santa Cruz esteve baseada num total de 35.971 pares de pontos (profundidade e localização geográfica) e Umari, 26.575. O reservatório Santa Cruz apresentou 15.984 m de comprimento máximo, 13 m de profundidade média e 38 m de profundidade máxima. Já Umari apresentou para esses mesmos parâmetros 14.227 m, 8 m e 28 m, respectivamente. O volume total de armazenamento em Santa Cruz foi de 295.858.761 m3 e o seu perímetro foi de 94.835 m. Já o reservatório de Umari apresentou um volume total de 114.866.034 m3 e perímetro de 110.887 m. Os reservatórios apresentaram baixa profundidade relativa que induz a uma possível instabilidade térmica e, consequentemente, uma mistura das massas de águas. Os resultados da ACP nos reservatórios Santa Cruz e Umari demonstraram um padrão espacial onde à medida que se aproximava da zona de influência fluvial foram registrados valores mais elevados de CE, STD, P-total, N-total e clorofila a. No entanto, em ambos os reservatórios não foi constatado um nítido padrão de variação temporal, provavelmente devido aos índices pluviométricos reduzidos observados durante todo o período de coletas. Os reservatórios apresentaram-se aptos a serem utilizados pelos diversos usos múltiplos conforme a resolução n° 357/2005 - CONAMA, tendo os valores médios das variáveis limnológicas enquadrados na Classe 1, a exceção do fósforo total que esteve dentro do limite para Classe 2 no reservatório Santa Cruz. Pôde-se concluir que o clássico conceito de compartimentalização longitudinal com a evidência das três zonas (fluvial, transição e lacustre) não foi aplicado aos reservatórios estudados, sendo apenas possível identificar uma compartimentalização parcial, evidenciando duas Zonas bem definidas, a Zona Lacustre, ocupando a maior parte de ambos os reservatórios com características ultraoligotrófica e oligotrófica e uma Zona de influência Fluvial reduzida, variando de mesotrófica e eutrófica

Given current rates of anthropogenic environmental change, combined with the increasing lethal and non-lethal mortality threat that human activities pose, there is a vital need to understand wildlife movement and behaviour in human-dominated landscapes to help inform conservation efforts and wildlife management. As long-term monitoring of wildlife populations using Global Positioning System (GPS) telemetry increases, there are new opportunities to quantify change in wildlife movement and behaviour. The objective of this PhD research is to develop novel methodological approaches for quantifying change in spatial-temporal patterns of wildlife movement and habitat by leveraging long time series of GPS telemetry and remotely sensed data. Analyses were focused on the habitat and movement of individuals in the threatened grizzly bear (Ursus arctos) population of Alberta, Canada, which occupies a human-dominated and heterogeneous landscape. Using methods in functional data analysis, a multivariate regionalization approach was developed that effectively summarizes complex spatial-temporal patterns associated with landscape disturbance, as well as recovery, which is often left unaccounted in studies quantifying patterns associated with disturbance. Next, the quasi-experimental framework afforded by a hunting moratorium was used to compare the influence of lethal (i.e., hunting) and non-lethal (i.e., anthropogenic disturbance) human-induced risk on antipredator behaviour of an apex predator, the grizzly bear. In support of the predation risk allocation hypothesis, male bears significantly decrease risky daytime behaviours by 122% during periods of high lethal human-induced risk. Rapid behavioural restoration occurred following the end of the hunt, characterized by diel bimodal movement patterns which may promote coexistence of large predators in human-dominated landscapes. A multi-scale approach using hierarchical Bayesian models, combined with post hoc trend tests and change point detection, was developed to test the influence of landscape disturbance and conditions on grizzly bear home range and movement selection over time. The results, representing the first longitudinal empirical analysis of grizzly bear habitat selection, revealed selection for habitat security at broad scales and for resource availability and habitat permeability at finer spatial scales, which has influenced potential landscape connectivity over time. Finally, combining approaches in movement ecology and conservation physiology, a body condition index was used to characterize how the physiological condition (i.e., internal state) of grizzly bears influences behavioral patterns due to costs and benefits associated with risk avoidance and resource acquisition. The results demonstrated individuals in poorer condition were more likely to engage in risky behaviour associated with anthropogenic disturbance, which highlights complex challenges for carnivore conservation and management of human-carnivore conflict. In summary, this dissertation contributes 1) a multivariate regionalization approach for quantifying spatial-temporal patterns of landscape disturbance and recovery applicable across diverse natural systems, 2) support for the growing theory that apex predators modify behavioural patterns to account for temporal overlap with lethal and non-lethal human-induced risk associated with humans, 3) an integrated approach for considering multi-scale spatial-temporal change in patterns of wildlife habitat selection and landscape connectivity associated with landscape change, 4) a cross-disciplinary framework for considering the impacts of the internal state on behavioural patterns and risk tolerance. / Graduate

The study presents the spatio-temporal assessment of groundwater-surface water (GW-SW) interaction aspects in the Schoonspruit River catchment, North West of South Africa. The research study aimed at improving understanding of groundwater and surface water interaction through assessing its location and time when such interaction occurs. GW-SW interaction sites were identified using principal aquifer type characterization methods. The occurrence of the interaction was established using hydrochemistry methods and the effectiveness of the existing monitoring methods were evaluated in their consideration of GW-SW interaction within the study area. The main results from the study showed that there was GW-SW interaction in the Schoonspruit River catchment which was not affected by seasonal changes. The result further showed that existing monitoring methods in the study catchment were not effective in addressing GW-SW interaction. The study concluded that qualitative methods are essential in studying GW-SW interaction and that monitoring methods for such interactions are required / Centre for Sustainable Agriculture and Environmental Sciences / M. Sc. (Environmental Management)

Made available in DSpace on 2016-12-23T13:51:55Z (GMT). No. of bitstreams: 1 kmila Gomes da Silva.pdf: 1840290 bytes, checksum: 71792d0ca0267bf6f9206f3a5d471245 (MD5) Previous issue date: 2013-03-12 / The analysis of the plant covering behavior on a temporal scale addresses practices that make forest remnant sustainability possible. The present study seeks to analyze the dynamics of the forest fragments in the hydrographic subbasin of the Alegre river, Espirito Santo state, based on the alterations of the plant covering and the structure of the forest landscape on a space-time scale, through two chapters. The first is based on the hypothesis that vegetation indexes can express similar vegetative or differentiated vigor of canopies of a specific area. To test the hypothesis, the objective was to to compare three vegetation indexes: TVI (Transformed Vegetation Index), CTVI (Corrected Transformed Vegetation Index) and RATIO (Ratio Vegetation Index), in relation to the behavior of NDVI (Normalized Difference Vegetation Index), regarding the discrimination of the vegetative vigor, as well as the alterations in the forest cover between 1987 and 2010. Through the obtained results, it was verified that the vegetation indexes allowed to estimate the vegetative vigor of the plant covering. A 4.90% (NDVI) increase and one of 7.78% (TVI) of forest covering, a pasture reduction of 3.34% (NDVI) and 5.53% (TVI) and a reduction of nonvegetated areas of 5.93% (NDVI) and 3.35% (TVI), in the period between 1987 and 2010 were evidenced. The natural regeneration process might have been the decisive factor for the area increrease and the changes in the forest vegetation of the area. The second chapter was based on the hypotheses that:1) In the forest landscape the predominance of fragments of small area occured during the years studied (1975, 2002 and 2007); 2) there is a predominance of forest fragments with complex forms and with smaller central area; 3) The forest remnants are isolated and with a larger border area. Based on the above, the aim was to characterize the space and temporal evolution of the forest fragment structures using landscape ecology metrics applied in the years of 1975, 2002 and 2007; the structural analysis of the forest fragments was conducted contemplating area parameters, form, nucleus, border and proximity by size classes. Based on the obtained results, a 7% increase was verified in the total area of the forest covering with the appearance of 645 new fragments. The number of fragments increased and the area of contribution small, which implied in the high border/area ratio. The smallest fragments (< 1 ha.) presented simple geometric form in relation to the others. The largest forest fragments (> 20 ha.) were shown proximate, presenting a tendency towards reduction of the proximity measure values / A análise do comportamento da cobertura vegetal numa escala temporal direciona práticas que viabilizam a sustentabilidade dos remanescentes florestais. O presente estudo visa analisar a dinâmica dos fragmentos florestais na sub-bacia hidrográfica do rio Alegre-ES, com base nas alterações da cobertura vegetal e na estrutura da paisagem florestal em uma escala espaço temporal, por meio de dois capítulos. O primeiro deles com base na hipótese de que índices de vegetação podem expressar vigores vegetativos semelhantes ou diferenciados, de dosséis de uma determinada região. Para testar a hipótese, objetivou-se comparar três índices de vegetação: TVI (Transformed Vegetation Index), CTVI (Corrected Transformed Vegetation Index) e RATIO (Ratio Vegetation Index), em relação ao comportamento do NDVI (Normalized Difference Vegetation Índex), quanto à discriminação do vigor vegetativo, bem como as alterações na cobertura florestal entre 1987 e 2010. Por meio dos resultados obtidos, verificou-se que os índices de vegetação permitiram estimar o vigor vegetativo da cobertura vegetal. Evidenciou-se o aumento da cobertura florestal de 4,90% (NDVI) e 7,78% (TVI), redução de pastagens de 3,34% (NDVI) e 5,53% (TVI), e redução de áreas não vegetadas de 5,93% (NDVI) e 3,35% (TVI), entre o período de 1987 e 2010. O processo de regeneração natural pode ter sido o fator determinante para o incremento de área e as mudanças na vegetação florestal da região. Já o segundo capítulo, baseou-se nas hipóteses de que: 1) Na paisagem florestal ocorre a predominância de fragmentos de pequena área durante os anos estudados (1975, 2002 e 2007); 2) Há predominância de fragmentos florestais com formas complexas e com menor área central; 3) Os remanescentes florestais estão isolados e com maior área de borda. Diante disso, objetivou-se caracterizar a evolução espacial e temporal das estruturas dos fragmentos florestais, utilizando as métricas da ecologia da paisagem aplicadas nos anos de 1975, 2002 e 2007; a análise estrutural dos fragmentos florestais foi realizada contemplando parâmetros de área, forma, núcleo, borda e proximidade em classes de tamanho. Com base nos resultados obtidos, verificou-se um aumento de 7% na área total da cobertura florestal com o surgimento de 645 novos fragmentos. O número de fragmentos foi elevado e a área de contribuição pequena, o que implicou na alta relação de borda/área. Os menores fragmentos (< 1 ha) apresentaram forma geométrica simples, em relação aos demais. Os maiores fragmentos florestais ( > 20 ha) mostraram-se próximos, apresentando uma tendência de redução nos valores da métrica de proximidade

Made available in DSpace on 2016-06-02T20:18:12Z (GMT). No. of bitstreams: 1 2959.pdf: 1881236 bytes, checksum: 0562673d7f2deff6e61218a2842d970d (MD5) Previous issue date: 2010-05-03 / Universidade Federal de Minas Gerais / This work consists of two studies. The aim of the first study was to investigate quadriceps and hamstring muscle volumes and strength deficits of the knee extensors and flexors in people with chronic hemiparesis compared to a healthy group. Fifteen individuals with chronic stroke and fifteen healthy individuals took part in this study. Motor function, quadriceps and hamstring muscle volume (MV), and maximal concentric and eccentric contractions of the knee extensors and flexors were obtained. The quadriceps muscle showed a reduction in MV. The peak torque of the paretic and non paretic limbs knee extensors and flexors was reduced in both contraction modes and velocities. There were significant correlations between motor function and strength deficits. With regard to muscle mass, there was a difference between quadriceps and hamstring response. There was no disuse atrophy; however this did not prevent extensor torque reduction. The aim of the second study was to investigate the effects of ground level gait training combining body weight support (BWS) and functional electrical stimulation (FES). Twelve people following chronic stroke. An A1-B-A2 system was applied; A1 and A2 corresponded to ground level gait training using BWS, and B corresponded to the same training associated to FES. The analyzed variables were: mean walking speed of locomotion; step length; stride length, speed and duration; initial and final double support duration; single-limb support duration; swing period; range of motion (ROM), maximum and minimum angles of foot, leg, thigh, and trunk segments. Mean walking speed, stride length and speed increased. Regarding the ROMs, there was a significant increase for leg and thigh. There was not improvement in the variables measured during the FES phase. Ground level gait training using BWS was effective to improve some gait, and the association to FES did not provide any additional improvement in the measured parameters. / Esse trabalho é composto por dois estudos. O objetivo do primeiro estudo foi investigar os volumes dos músculos quadríceps e isquiotibiais e os déficits de força dos músculos extensores e flexores do joelho em hemiparéticos crônicos comparados a um grupo controle saudável. Quinze indivíduos com hemiparesia crônica e 15 indivíduos saudáveis fizeram parte do estudo. Foram obtidos: pontuação da função motora geral, volume muscular (VM) dos músculos quadríceps e isquiotibiais e contrações concêntricas e excêntricas dos músculos extensores e flexores do joelho. O músculo quadríceps do membro parético apresentou redução no VM comparado ao membro contralateral. Os picos de torque extensor e flexor dos membros parético e contralateral apresentaram-se reduzidos para ambos os modos de contração e ambas as velocidades e correlações entre a função motora e os déficits de força muscular foram encontradas. Observou-se que há diferentes respostas entre os músculos quadríceps e isquiotibiais com relação à massa muscular. Não foi observada atrofia muscular por desuso. Entretanto, esse fato não preveniu a redução do torque articular. O objetivo do segundo estudo foi investigar os efeitos de um treinamento de marcha, em piso fixo, associado ao suporte parcial de peso corporal (SPPC) e à estimulação elétrica funcional (EEF) do nervo fibular comum, em hemiparéticos crônicos. Participaram do estudo 12 hemiparéticos crônicos. O sistema adotado foi o A1-B-A2, no qual A correspondeu ao treinamento de marcha em piso fixo com SPPC e B ao mesmo treinamento associado à EEF. Foram analisadas: velocidade média de locomoção, comprimento do passo, comprimento, velocidade e duração da passada; duração dos períodos de apoio duplo inicial e final, apoio simples e balanço; ângulos máximos e mínimos e amplitude de movimento (ADM) dos segmentos pé, perna, coxa e tronco dos membros parético e não-parético. Houve um aumento na velocidade média e no comprimento e velocidade do ciclo. Com relação às ADMs, houve aumento significativo entre as avaliações para o segmentos: perna e coxa após. Não houve melhora nas variáveis mensuradas na fase de EEF. Concluímos que o treinamento com SPPC, em piso fixo, foi efetivo na melhora de alguns aspectos da marcha e a associação à EEF não promoveu melhora adicional dos parâmetros mensurados.

Made available in DSpace on 2014-08-20T13:25:42Z (GMT). No. of bitstreams: 1 Dissertacao_Glaucia_Oliveira_Islabao.pdf: 11691653 bytes, checksum: aa0c46c1206ac7ab555f7587ceb58264 (MD5) Previous issue date: 2009-03-30 / Strawberry crop is an important option for small properties, being of great relevance for people fixation at countryside and generation and maintenance of rural jobs. Studies related to soil attributes monitoring, which can be used as soil quality indicators, are important to evaluate the sustainability of agricultural practices and to point to sound environment management, aiming to its conservation. This work intended to analyze the spatial and temporal variability of the chemical and microbiological soil attributes during the strawberry crop cycle in fourteen rural properties affiliated to the Association of Strawberry Producers of Turuçu-RS, to identify and evaluate the potential impacts of irrigation water on these attributes and to propose actions to minimize these impacts if needed. In this way, deformed soil samples were collected in four different periods at depth 0-0.20 m, to determine their chemical attributes (organic matter, active and potential acidity, CEC and at pH 7.0, base saturation and aluminum saturation), microbiological (carbon and nitrogen of microbial biomass, basal respiration and metabolic quotient) and about fertility (total nitrogen, phosphorus, potassium, copper and zinc). In order to evaluate the mean values of all attributes along the time in each property was applied the LSD mean comparison test with significance to 5%. The spatial and temporal variability of all attributes were evaluataded by means of box plots. Results indicated that between the soil chemical indicators, the mean values of potential acidity presented the major significant variation along the time, while the mean values of aluminum saturation presented the minor variation. Between the soil microbiological indicators, the mean basal respiration presented the major significant variation along the time, while the mean values of nitrogen of microbial biomass presented the minor variation. Between soil fertility indicators the mean values of copper presented the major significant variation along the time, while the mean values of zinc presented the minor variation. With regard to the spatial and temporal variability of the chemical indicators it was found that organic matter presented the greatest amplitude and the aluminum saturation the lowest. Regarding to the spatial and temporal variability of the microbiological indicators it was found that carbon of microbial biomass presented the greatest amplitude while the metabolic quotient presented the lowest. Regarding to the spatial and temporal variability of the soil fertility indicators it was found that copper presented the greatest amplitude while zinc presented the lowest. The concentrations of phosphorus, potassium, copper and zinc presented high levels in all strawberry crops. The organic matter levels were classified as low in most strawberry crops. It was not possible to identify the impact of irrigation water over the chemical and soil fertility indicators, meanwhile, there was a possible impact over the microbiological indicators, specially over the carbon and nitrogen of microbial biomass and metabolic quotient. / A cultura do morango é uma importante alternativa para pequenas propriedades, sendo de grande importância para a fixação do homem no campo e para a geração e manutenção de emprego na área rural. Estudos relativos ao monitoramento dos atributos do solo, que podem ser utilizados como indicadores de qualidade do solo, são importantes para avaliar a sustentabilidade das práticas agrícolas, além de sinalizar o manejo adequado do ambiente visando à sua conservação. Em virtude disto, este trabalho teve como objetivos estudar a variabilidade espacial e temporal dos atributos químicos e microbiológicos do solo ao longo do ciclo de produção da cultura do morango em quatorze propriedades pertencentes a Associação de Produtores de Morango do município de Turuçu/RS, identificar e avaliar os possíveis impactos da água de irrigação sobre estes atributos e propor ações para minimizar estes impactos caso existirem. Para tal, foram coletadas, em quatro diferentes épocas e na profundidade de 0-0,20 m, amostras deformadas de solo em cada uma das propriedades, determinando seus atributos químicos (matéria orgânica, acidez ativa e potencial, CTC efetiva e pH 7,0, saturação por alumínio e saturação por bases), microbiológicos (carbono microbiano, nitrogênio microbiano, respiração basal e quociente metabólico) e de fertilidade (nitrogênio total, fósforo, potássio, cobre e zinco). Para verificar o comportamento dos valores médios de todos os atributos ao longo do tempo e em cada propriedade foi aplicado o teste de comparação de médias DMS, a nível de 5% de significância, enquanto que para avaliar a distribuição temporal e espacial de todos os atributos foram construídos gráficos em caixa. Os resultados indicaram que dentre os indicadores químicos do solo, os valores médios de acidez potencial foram os que mais diferiram significativamente ao longo do tempo, enquanto que os valores médios de saturação por alumínio foram os que menos diferiram; dentre os indicadores microbiológicos do solo, os valores médios de respiração basal foram os que mais diferiram significativamente ao longo do tempo, enquanto que os valores médios de nitrogênio microbiano foram os que menos diferiram ao longo do tempo; dentre os indicadores de fertilidade do solo, os valores médios de cobre foram os que mais diferiram significativamente ao longo do tempo, enquanto que os valores médios de zinco foram os que menos diferiram; quanto a variabilidade espacial e temporal dos indicadores químicos, foi constatado que a matéria orgânica apresentou a maior amplitude e a saturação por alumínio a menor; quanto a variabilidade espacial e temporal dos indicadores microbiológicos, foi constatado que o indicador carbono microbiano apresentou a maior amplitude e o quociente metabólico a menor; quanto a variabilidade espacial e temporal dos indicadores de fertilidade, foi constatado que o cobre apresentou a maior amplitude e o zinco a menor; as concentrações dos elementos fósforo, potássio, cobre e zinco encontram-se com elevados teores em todas as lavouras de morango; os teores de matéria orgânica foram classificados como baixos na maioria das lavouras de morango envolvidas neste estudo; não foi possível identificar o impacto da adição da água de irrigação sobre os indicadores químicos e de fertilidade do solo, entretanto, houve um possível impacto sobre os indicadores microbiológicos, principalmente, verificado sobre o carbono microbiano, nitrogênio microbiano e o quociente metabólico.

Cette thèse s’attache à développer des outils et modèles adaptés a l’étude de certains risques spatiaux et en réseaux. Elle est divisée en cinq chapitres. Le premier consiste en une introduction générale, contenant l’état de l’art au sein duquel s’inscrivent les différents travaux, ainsi que les principaux résultats obtenus. Le Chapitre 2 propose un nouveau générateur de précipitations multi-site. Il est important de disposer de modèles capables de produire des séries de précipitations statistiquement réalistes. Alors que les modèles précédemment introduits dans la littérature concernent essentiellement les précipitations journalières, nous développons un modèle horaire. Il n’implique qu’une seule équation et introduit ainsi une dépendance entre occurrence et intensité, processus souvent considérés comme indépendants dans la littérature. Il comporte un facteur commun prenant en compte les conditions atmosphériques grande échelle et un terme de contagion auto-regressif multivarié, représentant la propagation locale des pluies. Malgré sa relative simplicité, ce modèle reproduit très bien les intensités, les durées de sècheresse ainsi que la dépendance spatiale dans le cas de la Bretagne Nord. Dans le Chapitre 3, nous proposons une méthode d’estimation des processus maxstables, basée sur des techniques de vraisemblance simulée. Les processus max-stables sont très adaptés à la modélisation statistique des extrêmes spatiaux mais leur estimation s’avère délicate. En effet, la densité multivariée n’a pas de forme explicite et les méthodes d’estimation standards liées à la vraisemblance ne peuvent donc pas être appliquées. Sous des hypothèses adéquates, notre estimateur est efficace quand le nombre d’observations temporelles et le nombre de simulations tendent vers l’infini. Cette approche par simulation peut être utilisée pour de nombreuses classes de processus max-stables et peut fournir de meilleurs résultats que les méthodes actuelles utilisant la vraisemblance composite, notamment dans le cas où seules quelques observations temporelles sont disponibles et où la dépendance spatiale est importante / This thesis aims at developing tools and models that are relevant for the study of some spatial risks and risks in networks. The thesis is divided into five chapters. The first one is a general introduction containing the state of the art related to each study as well as the main results. Chapter 2 develops a new multi-site precipitation generator. It is crucial to dispose of models able to produce statistically realistic precipitation series. Whereas previously introduced models in the literature deal with daily precipitation, we develop a hourly model. The latter involves only one equation and thus introduces dependence between occurrence and intensity; the aforementioned literature assumes that these processes are independent. Our model contains a common factor taking large scale atmospheric conditions into account and a multivariate autoregressive contagion term accounting for local propagation of rainfall. Despite its relative simplicity, this model shows an impressive ability to reproduce real intensities, lengths of dry periods as well as the spatial dependence structure. In Chapter 3, we propose an estimation method for max-stable processes, based on simulated likelihood techniques. Max-stable processes are ideally suited for the statistical modeling of spatial extremes but their inference is difficult. Indeed the multivariate density function is not available and thus standard likelihood-based estimation methods cannot be applied. Under appropriate assumptions, our estimator is efficient as both the temporal dimension and the number of simulation draws tend towards infinity. This approach by simulation can be used for many classes of max-stable processes and can provide better results than composite-based methods, especially in the case where only a few temporal observations are available and the spatial dependence is high

Object tracking can be done in numerous ways, where the goal is to track a target through all frames in a sequence. The ground truth bounding box is used to initialize the object tracking algorithm. Object tracking can be carried out on infrared imagery suitable for military applications to execute tracking even without illumination. Objects, such as aircraft, can deploy countermeasures to impede tracking. The countermeasures most often mainly impact one wavelength band. Therefore, using two different wavelength bands for object tracking can counteract the impact of the countermeasures. The dataset was created from simulations. The countermeasures applied to the dataset are flares and Directional Infrared Countermeasures (DIRCMs). Different object tracking algorithms exist, and many are based on discriminative correlation filters (DCF). The thesis investigated the DCF-based trackers STRCF and ECO on the created dataset. The STRCF and the ECO trackers were analyzed using one and two wavelength bands. The following features were investigated for both trackers: grayscale, Histogram of Oriented Gradients (HOG), and pre-trained deep features. The results indicated that the STRCF and the ECO trackers using two wavelength bands instead of one improved performance on sequences with countermeasures. The use of HOG, deep features, or a combination of both improved the performance of the STRCF tracker using two wavelength bands. Likewise, the performance of the ECO tracker using two wavelength bands was improved by the use of deep features. However, the negative aspect of using two wavelength bands and introducing more features is that it resulted in a lower frame rate.

<p>    </p> <p>The counting process is the fundamental of many real-world problems with event data. Poisson process, used as the background intensity of Hawkes process, is the most commonly used point process. The Hawkes process, a self-exciting point process fits to temporal event data, spatial-temporal event data, and event data with covariates. We study the Hawkes process that fits to heterogeneous drug overdose data via a novel semi-parametric approach. The counting process is also related to survival data based on the fact that they both study the occurrences of events over time. We fit a Cox model to temporal event data with a large corpus that is processed into high dimensional covariates. We study the significant features that influence the intensity of events. </p>

Indiana University-Purdue University Indianapolis (IUPUI) / A massive amount of videos are uploaded on video websites, smooth video browsing, editing, retrieval, and summarization are demanded. Most of the videos employ several types of camera operations for expanding field of view, emphasizing events, and expressing cinematic effect. To digest heterogeneous videos in video websites and databases, video clips are profiled to 2D image scroll containing both spatial and temporal information for video preview. The video profile is visually continuous, compact, scalable, and indexing to each frame. This work analyzes the camera kinematics including zoom, translation, and rotation, and categorize camera actions as their combinations. An automatic video summarization framework is proposed and developed. After conventional video clip segmentation and video segmentation for smooth camera operations, the global flow field under all camera actions has been investigated for profiling various types of video. A new algorithm has been designed to extract the major flow direction and convergence factor using condensed images. Then this work proposes a uniform scheme to segment video clips and sections, sample video volume across the major flow, compute flow convergence factor, in order to obtain an intrinsic scene space less influenced by the camera ego-motion. The motion blur technique has also been used to render dynamic targets in the profile. The resulting profile of video can be displayed in a video track to guide the access to video frames, help video editing, and facilitate the applications such as surveillance, visual archiving of environment, video retrieval, and online video preview.