Depuis le début des années 80, les progrès techniques permettent des estimations quantitatives des relations entre les structures internes de la Terre et sa forme. Des méthodes statistiques appliquées à un modèle tomographique de la Méditerranée permettent d’extraire 3 composantes qui capturent 70% de la variance des données. La première correspond à la réaction du manteau supérieur à la présence de lithosphère à 660 km, la seconde enregistre la réaction du manteau aux slabs subverticaux dans le manteau supérieur, la troisième capture les variations de vitesse sismiques du sommet des manteaux supérieur et inférieur. L’effet de ces 3 phénomènes sur le géoïde est modélisé en considérant : (i) Toutes les anomalies enregistrées par les données tomographiques constituent des sources d’anomalies. Leur effet est calculé en utilisant la gravito-visco-élasticité. Il semble que cette approche ne suffit pas à modéliser l’ensemble de la composante mantellique. (ii) les données tomographiques enregistrent les sources d’anomalies et tous les phénomènes de réajustement. En intégrant les anomalies de masses données par le modèle tomographique on obtient des structures détaillées qui surestiment la composante mantellique. (ii) Chaque composante isole des phénomènes du manteau liés à une source à laquelle est appliquée la théorie de la gravito-visco-élasticité. La composante mantellique obtenue est de longueur d'onde et amplitude compatibles avec le géoïde.La présence de calottes de lithosphère à la base de la zone de transition est susceptible d’être visible par le géoïde contrairement à la présence de slabs subverticaux dans le manteau supérieur / Progress made in seismic tomography and geodesy open the way to estimations of relations between the structures within the Earth and its shape. Applying statistical analysis to tomographic data of the mediterranean area, we extract 3 components that capture almost 70 % of the variance of the tomographic data : first one isolates the mantle reaction to lithospheric masses from the bottom of the transition zone, the second one is legated to subvertical lithsopheric slabs in the upper mantle, the third one corresponds to the tops of upper- and lower- mantle expression. Effect of these dynamics on the geoid has been modelized using considering that : (i) all the structures of the tomographic model are geoid anomaly sources, mantle component of the geoid is computed applying the gravito-visco-elasticity theory to take into account deflection of viscosity interfaces. This approach provides a smooth and low amplitude geoid mantle component. (ii) the tomographic model can register sources but also the all readjustment. Mantle component of the geoid is computed integrating anomalies of the model. It provides a detailled but too large with respect with the regional geoid mantle component. (iii) each component has capacity to isolate a phenomenon legated to a specific source of geoid anomalies. We applied gravito-visco-elastic theory specifically to it. That provides a mantle component detailled and that has a magnitude low enough with respect to the geoid.The presence of lithospheric caps on the bottom of the transition zone can be detected by the mantellic component of the geoid, but the geoid is not sensitive to subvertical slabs within the upper mantle

Byggnadsrelaterad ohälsa (BRO) är en av flera miljökänsligheter. De två konstrukten modern hälsooro (MHO) och somatosensorisk förstärkning (SSA) har båda visat sig kopplade till nocebo och de uppvisas ofta hos personer med miljökänsligheter. Det första syftet med uppsatsen var att öka förståelsen för vilka symtom som kännetecknar BRO, vilket undersöktes via 20 items utvalda från The Idiopathic Enviromental Intolerance Symtom Inventory (IEISI) vilka överensstämmer med WHOs lista över BRO-symtom. Det andra syftet var att öka kunskapen om vilken roll nocebo har i BRO, vilket undersöktes via Modern Health Worries (MHWS) och Somatosensory Amplification Scale (SSAS). Data inhämtades från en pågående studie vid Umeå Universitet. Urvalsgruppen utgjordes av 79 individer som uppgett att de upplevde BRO-symtom varje vecka. Data analyserades via korrelationsanalyser. Gruppen uppvisade variation i vilka och hur många symtom individerna rapporterade. Resultatet från korrelationsanalyserna visade sammantaget på att nocebo inte hade en betydande roll i rapporterandet av BRO-symtom i urvalsgruppen. Studien visade att gruppen med BROpatienter varken oroade sig mer än norm eller var särskilt känsliga för sensoriska intryck. / Building Related Illness (BRI) is one of several environmental sensitivities. The two constructs Modern Health Worries (MHW) and Somatosensory Amplification (SSA) have both been shown to be linked to nocebo and are often reported by people with environmental sensitivities. The first purpose of this paper was to increase the understanding of symptoms that characterize BRI, which was investigated via 20 items selected from The Idiopathic Enviromental Intolerance Symptom Inventory (IEISI) that complies with WHO's list of BRI symptoms. The second purpose was to increase knowledge about the role of nocebo in BRI, which was investigated via Modern Health Worries Scale (MHWS) and Somatosensory Amplification Scale (SSAS). Data was obtained from an ongoing study at Umeå University. The sample consisted of 79 individuals who reported that they experienced BRI symptoms each week. Data was analyzed via correlation analyzes. The group showed variability concerning which and how many symptoms the individuals reported. The results from the correlation analyzes showed that nocebo did not play a significant role in the reporting of BRI symptoms in the selection group. The study showed that the group of BRI patients neither worry more than the norm nor was particularly sensitive to sensory impressions.

El objetivo de la presente investigación fue describir los valores de jóvenes universitarios chilenos de cuatro regiones del país y determinar si existen diferencias entre éstos en función de su región de pertenencia. Para esto se aplicó el Cuestionario de Valores (CDV), basado en la teoría universal del contenido motivacional de Schwartz, a una muestra de 981 estudiantes universitarios de las regiones de Arica y Parinacota, Libertador Bernardo O’Higgins, Los Ríos y Magallanes y Antártica Chilena, seleccionados por medio de un muestreo probabilístico. Utilizando Análisis del Espacio Menor (SSA), una técnica no paramétrica de Escalamiento Multidimensional, se evaluaron los contenidos, estructuras y jerarquías de valores. Los contenidos y estructuras valóricas se agruparon según los diez tipos valóricos descritos por la teoría, mientras que los valores más salientes fueron Benevolencia, Autodirección y Universalismo en todas las regiones. Finalmente, se discute sobre los resultados obtenidos y las posibilidades de estudios posteriores

Attenuating random and coherent noise is an important part of seismic data processing. Successful removal results in an enhanced image of the subsurface geology, which facilitate economical decisions in hydrocarbon exploration. This motivates the search for new and more efficient techniques for noise removal. The main goal of this thesis is to present an overview of the Singular Spectrum Analysis (SSA) technique, studying its potential application to seismic data processing. An overview of the application of SSA for time series analysis is presented. Subsequently, its applications for random and coherent noise attenuation, expansion to multiple dimensions, and for the recovery of unrecorded seismograms are described. To improve the performance of SSA, a faster implementation via a randomized singular value decomposition is proposed. Results obtained in this work show that SSA is a versatile method for both random and coherent noise attenuation, as well as for the recovery of missing traces. / Geophysics

No description available.

Submitted by Felipe Lapenda (felipe.lapenda@ufpe.br) on 2015-03-06T14:16:11Z No. of bitstreams: 2 TESE ZILURDES FONSECA LOPES.pdf: 14894118 bytes, checksum: f840c9480c046d9e841a11a86b03330a (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-06T14:16:11Z (GMT). No. of bitstreams: 2 TESE ZILURDES FONSECA LOPES.pdf: 14894118 bytes, checksum: f840c9480c046d9e841a11a86b03330a (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2014-08-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A mudança hidroclimática tem sido analisada por diferentes pesquisadores no mundo levando em consideração a variação climática, fatores antrópicos e características físicas da bacia hidrográfica. Este estudo teve como objetivo detectar tendência e modos oscilatórios dominantes nas séries de precipitação e vazão na bacia do rio São Francisco e também verificar se a ação antrópica pode transformar a forçante atmosférica sobre a precipitação e vazão a fim de verificar se há mudanças hidroclimática na bacia. Os componentes de tendências e modos oscilatórios que compõem o sinal da série de precipitação e vazão foram extraídos por meio da técnica de Análise Espectral Singular. A Análise de Componentes Principais foi utilizada para regionalizar as séries de precipitação e vazão. Na parte alta da bacia observou-se tendência de aumento de precipitação enquanto que o Médio e Submédio São Francisco indicaram tendência decrescente nos dados de precipitação. Os modos oscilatórios da escala intrasazonal são os principais que causam precipitação no Médio São Francisco, no entanto essa escala foi dominada pela escala interanual e decadal. Na parte alta da bacia, foram observadas oscilações frequentes de modo de 12, 6, 18 e 24 meses como parte do sinal da dinâmica base. O Submédio São Francisco apresentou como principais modos oscilatórios, depois do modo de doze meses, os de três a sete anos e também aqueles de escala temporal decadal. Os modos oscilatórios detectados nas séries de vazão foram aqueles da escala intrasazonal, interanual e decadal em todas as regiões da bacia. Quanto à regionalização, a bacia foi regionalizada em cinco regiões. Três regiões foram formadas por características comuns devido a fatores atmosféricos e uma região, composta apenas por postos de vazão com características de ação antrópica, nos municípios. Em geral, não foi observado mudança de regime de precipitação nas regiões do rio São Francisco. Quanto a vazão, percebeu-se decréscimos nos dados fluviométricos, principalmente após a década de 80, nas regiões do Médio, Submédio e Baixo São Francisco.

Please read the abstract in the 00front of this document. / Thesis (PhD)--University of Pretoria, 2011. / Economics / unrestricted

Rapid population growth and climate variability have been posing pressure on groundwater management, especially in regions dominated by irrigation agriculture. Effective management practices require a better understanding of groundwater dynamics and its contributing factors, such as recharge, groundwater-surface water interactions, soil and unsaturated zone characteristics. Although groundwater models can provide valuable insights into these questions, these models are often nonexistent or cost prohibitive.

We consider the problem of synthesizing program inverses for imperative languages. Our primary motivation comes from optimistic parallel discrete event simulation (OPDES). There, a simulator must process events while respecting logical temporal event-ordering constraints; to extract parallelism, an OPDES simulator may speculatively execute events and only rollback execution when event-ordering violations occur. In this context, the ability to perform rollback by running time- and space-efficient reverse programs, rather than saving and restoring large amounts of state, can make OPDES more practical. Synthesizing inverses also appears in numerous other software engineering contexts, such as debugging, synthesizing “undo” code, or even generating decompressors automatically given only lossless compression code. This thesis mainly contains three chapters. In the first chapter, we focus on handling programs with only scalar data and arbitrary control flows. By building a value search graph (VSG) that represents recoverability relationships between variable values, we turn the problem of recovering previous values into a graph search one. Forward and reverse programs are generated according to the search results. For any loop that produces an output state given a particular input state, our method can synthesize an inverse loop that reconstructs the input state given the original loop's output state. The synthesis process consists of two major components: (a) building the inverse loop's body, and (b) building the inverse loop's predicate. Our method works for all natural loops, including those that take early exits (e.g., via breaks, gotos, returns). In the second chapter we extend our method to handling programs containing arrays. Based on Array SSA, we develop a modified Array SSA from which we could easily build equalities between arrays and array elements. Specifically, to represent the equality between two arrays, we employ the array subregion as the constraint. During the search those subregions will be calculated to guarantee that all array elements will be retrieved. We also develop a demand-driven method to retrieve array elements from a loop, in which each time we only try to retrieve an array element from an iteration if that element has not been modified in previous iterations. To ensure the correctness of each retrieval, the boundary conditions are created and checked at the entry and the exit of the loop. In the last chapter, we introduce several techniques of handling high-level constructs of C++ programs, including virtual functions, copying C++ objects, C++ STL containers, C++ source code normalization, inter-procedural function calls, etc. Since C++ is an object-oriented (OO) language, our discussion in this chapter can also be extended to other OO languages like Java.

In this thesis we study stochastic modeling and simulation methods for biochemical systems. The thesis is focused on systems with multi-state and multi-scale features and divided into two parts. In the first part, we propose new algorithms that improve existing multi-state simulation methods. We first compare the well known Gillespie\\\'s stochastic simulation algorithm (SSA) with the StochSim, an agent-based simulation method. Based on the analysis, we propose a hybrid method that possesses the advantages of both methods. Then we propose two new methods that extend the Network-Free Algorithm (NFA) for rule-based models. Numerical results are provided to show the performance improvement by our new methods. In the second part, we investigate two simulation schemes for the multi-scale feature: Haseltine and Rawlings\\\' hybrid method and the quasi-steady-state stochastic simulation method. We first propose an efficient partitioning strategy for the hybrid method and an efficient way of building stochastic cell cycle models with this new partitioning strategy. Then, to understand conditions where the two simulation methods can be applied, we develop a way to estimate the relaxation time of the fast sub-network, and compare it with the firing interval of the slow sub-network. Our analysis are verified by numerical experiments on different realistic biochemical models. / Ph. D.