873 resultados para Multi-scale modeling


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Theories on the link between achievement goals and achievement emotions focus on their within-person functional relationship (i.e., intraindividual relations). However, empirical studies have failed to analyze these intraindividual relations and have instead examined between-person covariation of the two constructs (i.e., interindividual relations). Aiming to better connect theory and empirical research, the present study (N = 120 10th grade students) analyzed intraindividual relations by assessing students’ state goals and emotions using experience sampling (N = 1,409 assessments within persons). In order to replicate previous findings on interindividual relations, students’ trait goals and emotions were assessed using self-report questionnaires. Despite being statistically independent, both types of relations were consistent with theoretical expectations, as shown by multi-level modeling: Mastery goals were positive predictors of enjoyment and negative predictors of boredom and anger; performance-approach goals were positive predictors of pride; and performance-avoidance goals were positive predictors of anxiety and shame. Reasons for the convergence of intra- and interindividual findings, directions for future research, and implications for educational practice are discussed.

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Anticipation is increasingly central to urgent contemporary debates, from climate change to the global economic crisis. Anticipatory practices are coming to the forefront of political, organizational, and citizens’ society. Research into anticipation, however, has not kept pace with public demand for insights into anticipatory practices, their risks and uses. Where research exists, it is deeply fragmented. This paper seeks to identify how anticipation is defined and understood in the literature and to explore the role of anticipatory practice to address individual, social, and global challenges. We use a resilience lens to examine these questions. We illustrate how varying forms of anticipatory governance are enhanced by multi-scale regional networks and technologies and by the agency of individuals, drawing from an empirical case study on regional water governance of Mälaren, Sweden. Finally, we discuss how an anticipatory approach can inform adaptive institutions, decision making, strategy formation, and societal resilience.

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The polynyas of the Laptev Sea are regions of particular interest due to the strong formation of Arctic sea-ice. In order to simulate the polynya dynamics and to quantify ice production, we apply the Finite Element Sea-Ice Ocean Model FESOM. In previous simulations FESOM has been forced with daily atmospheric NCEP (National Centers for Environmental Prediction) 1. For the periods 1 April to 9 May 2008 and 1 January to 8 February 2009 we examine the impact of different forcing data: daily and 6-hourly NCEP reanalyses 1 (1.875° x 1.875°), 6-hourly NCEP reanalyses 2 (1.875° x 1.875°), 6-hourly analyses from the GME (Global Model of the German Weather Service) (0.5° x 0.5°) and high-resolution hourly COSMO (Consortium for Small-Scale Modeling) data (5 km x 5 km). In all FESOM simulations, except for those with 6-hourly and daily NCEP 1 data, the openings and closings of polynyas are simulated in principle agreement with satellite products. Over the fast-ice area the wind fields of all atmospheric data are similar and close to in situ measurements. Over the polynya areas, however, there are strong differences between the forcing data with respect to air temperature and turbulent heat flux. These differences have a strong impact on sea-ice production rates. Depending on the forcing fields polynya ice production ranges from 1.4 km3 to 7.8 km3 during 1 April to 9 May 2011 and from 25.7 km3 to 66.2 km3 during 1 January to 8 February 2009. Therefore, atmospheric forcing data with high spatial and temporal resolution which account for the presence of the polynyas are needed to reduce the uncertainty in quantifying ice production in polynyas.

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The degree to which habitat fragmentation affects bird incidence is species specific and may depend on varying spatial scales. Selecting the correct scale of measurement is essential to appropriately assess the effects of habitat fragmentation on bird occurrence. Our objective was to determine which spatial scale of landscape measurement best describes the incidence of three bird species (Pyriglena leucoptera, Xiphorhynchus fuscus and Chiroxiphia caudata) in the fragmented Brazilian Atlantic forest and test if multi-scalar models perform better than single-scalar ones. Bird incidence was assessed in 80 forest fragments. The surrounding landscape structure was described with four indices measured at four spatial scales (400-, 600-, 800- and 1,000-m buffers around the sample points). The explanatory power of each scale in predicting bird incidence was assessed using logistic regression, bootstrapped with 1,000 repetitions. The best results varied between species (1,000-m radius for P. leucoptera; 800-m for X. fuscus and 600-m for C. caudata), probably due to their distinct feeding habits and foraging strategies. Multi-scale models always resulted in better predictions than single-scale models, suggesting that different aspects of the landscape structure are related to different ecological processes influencing bird incidence. In particular, our results suggest that local extinction and (re)colonisation processes might simultaneously act at different scales. Thus, single-scale models may not be good enough to properly describe complex pattern-process relationships. Selecting variables at multiple ecologically relevant scales is a reasonable procedure to optimise the accuracy of species incidence models.

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We consider independent edge percolation models on Z, with edge occupation probabilities. We prove that oriented percolation occurs when beta > 1 provided p is chosen sufficiently close to 1, answering a question posed in Newman and Schulman (Commun. Math. Phys. 104: 547, 1986). The proof is based on multi-scale analysis.

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Differently from theoretical scale-free networks, most real networks present multi-scale behavior, with nodes structured in different types of functional groups and communities. While the majority of approaches for classification of nodes in a complex network has relied on local measurements of the topology/connectivity around each node, valuable information about node functionality can be obtained by concentric (or hierarchical) measurements. This paper extends previous methodologies based on concentric measurements, by studying the possibility of using agglomerative clustering methods, in order to obtain a set of functional groups of nodes, considering particular institutional collaboration network nodes, including various known communities (departments of the University of Sao Paulo). Among the interesting obtained findings, we emphasize the scale-free nature of the network obtained, as well as identification of different patterns of authorship emerging from different areas (e.g. human and exact sciences). Another interesting result concerns the relatively uniform distribution of hubs along concentric levels, contrariwise to the non-uniform pattern found in theoretical scale-free networks such as the BA model. (C) 2008 Elsevier B.V. All rights reserved.

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This paper presents a method for the quantification of cellular rejection in endomyocardial biopsies of patients submitted to heart transplant. The model is based on automatic multilevel thresholding, which employs histogram quantification techniques, histogram slope percentage analysis and the calculation of maximum entropy. The structures were quantified with the aid of the multi-scale fractal dimension and lacunarity for the identification of behavior patterns in myocardial cellular rejection in order to determine the most adequate treatment for each case.

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Scale-invariant running couplings are constructed for several quarks being decoupled together, without reference to intermediate thresholds. Large-momentum scales can also be included. The result is a multi-scale generalization of the renormalization group applicable to any order. Inconsistencies in the usual decoupling procedure with a single running coupling can then be avoided, e.g., when cancelling anomalous corrections from t, b quarks to the axial charge of the proton. (c) 2006 Elsevier B.V. All rights reserved.

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The urbanization of modern societies has imposed to the planners and decision-makers a more precise attention to facts not considered before. Several aspects, such as the energy availability and the deleterious effect of pollution on the populations, must be considered in the policy decisions of cities urbanization. The current paradigm presents centralized power stations supplying a city, and a combination of technologies may compose the energy mix of a country, such as thermal power plants, hydroelectric plants, wind systems and solar-based systems, with their corresponding emission pattern. A goal programming multi-objective optimization model is presented for the electric expansion analysis of a tropical city, and also a case study for the city of Guaratinguetá, Brazil, considering a particular wind and solar radiation patterns established according to actual data and modeled via the time series analysis method. Scenarios are proposed and the results of single environmental objective, single economic objective and goal programming multi-objective modeling are discussed. The consequences of each dispatch decision, which considers pollutant emission exportation to the neighborhood or the need of supplementing electricity by purchasing it from the public electric power grid, are discussed. The results revealed energetic dispatch for the alternatives studied and the optimum environmental and economic solution was obtained. © 2012 Elsevier Ltd.

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Spatial patterns in assemblage structures are generated by ecological processes that occur on multiple scales. Identifying these processes is important for the prediction of impact, for restoration and for conservation of biodiversity. This study used a hierarchical sampling design to quantify variations in assemblage structures of Brazilian estuarine fish across 2 spatial scales and to reveal the ecological processes underlying the patterns observed. Eight areas separated by 0.7 to 25 km (local scale) were sampled in 5 estuaries separated by 970 to 6000 km (regional scale) along the coast, encompassing both tropical and subtropical regions. The assemblage structure varied significantly in terms of relative biomass and presence/absence of species on both scales, but the regional variation was greater than the local variation for either dataset. However, the 5 estuaries sampled segregated into 2 major groups largely congruent with the Brazilian and Argentinian biogeographic provinces. Three environmental variables (mean temperature of the coldest month, mangrove area and mean annual precipitation) and distance between estuaries explained 44.8 and 16.3%, respectively, of the regional-scale variability in the species relative biomass. At the local scale, the importance of environmental predictors for the spatial structure of the assemblages differed between estuarine systems. Overall, these results support the idea that on a regional scale, the composition of fish assemblages is simultaneously determined by environmental filters and species dispersal capacity, while on a local scale, the effect of environmental factors should vary depending on estuary-specific physical and hydrological characteristics © 2013 Inter-Research.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Ciências Cartográficas - FCT

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A ferramenta de indução tem sido, desde 1949, largamente utilizada na prospecção de petróleo pois auxilia na localização de formações que contém hidrocarbonetos. Ainda existem, porém, várias restrições quanto ao uso deste equipamento. Camadas excessivamente finas, poços preenchidos com lamas muito condutivas e grandes diâmetros de invasão são exemplos de situações onde seu desempenho não é bom. Para que se possa minimizar estas limitações é necessário o conhecimento da resposta da sonda diante de condições conhecidas. Isto pode ser feito via modelamento analógico e/ou através de modelamento numérico. O presente trabalho consiste na montagem de um sistema de modelamento analógico capaz de simular o perfil de duas bobinas coaxiais frente a meios infinitos e camadas espessas invadidas. O meio geológico é representado através de solução salina de diferentes condutividades. O fator de escala linear é igual a 20 e o equipamento executa medidas na faixa dos 50 kHz aos 100 kHz. Este sistema será utilizado em futuros estudos envolvendo disposições de bobinas diferentes das normalmente utilizadas e em estudos de outros problemas encontrados na perfilagem de indução.

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Consoante a importância da atividade empresarial para o desenrolar das migrações de retorno, sobretudo no que se refere a mitigação dos riscos e problemas tipicamente vivenciados pelos protagonistas de tais deslocamentos, esta tese objetivou compreender e explicar o processo de formação das estratégias empreendedoras adotadas por dekasseguis retornados no estado do Pará. Para tanto, desenvolveu-se um estudo de caso eminentemente qualitativo, utilizando-se um conjunto amplo de dados, com destaque para as narrativas obtidas através de entrevistas semiestruturadas, procedidas não somente com indivíduos que criaram negócios após regressarem do Japão, mas também com gestores de organizações envolvidas com o movimento dekassegui em um sentido mais amplo. Os achados obtidos permitiram elaborar um modelo de análise bastante amplo e de caráter multiescalar, que promove um entendimento mais denso sobre as trajetórias migratórias e as iniciativas empresariais observadas, capaz de captar uma série de elementos que se confluem no processo de criação e desenvolvimento das estratégias em vista. Através dele, foi possível defender a tese que: as estratégias empresariais adotadas pelos dekasseguis retornados foram formadas por combinações entre oportunidades e restrições de caráter econômico, sociocultural e político/institucional existentes em cada etapa de seus trajetos migratórios, bem como, pelo contexto espacial e temporal em que suas escolhas e ações ocorreram. O que reforça, por sua vez, a necessidade de se utilizar abordagens sociológicas e métodos complementares no estudo desses fenômenos. Além, é claro, de proporcionar um conjunto de considerações e recomendações interessantes aos estudiosos do tema e os praticantes do campo: aspirantes a dekasseguis, dekasseguis retornados que já tenham iniciado seus próprios negócios, líderes de associações nikkeys, gestores de órgãos federais e estaduais, entre outros.

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Os estudos ambientais necessitam de informações sobre a cobertura e o uso da terra. Este trabalho apresenta a aplicação de dados de sensores remotos orbitais (óticos e de radares) na validação de padrões de uso e cobertura do solo na planície costeira amapaense para fins de mapeamento e reconhecimento da dinâmica natural e antrópica. Esta costa é submetida a uma dinâmica intensa devido à magnitude dos processos costeiros (marés-pororoca), sua localização geográfica, influenciada pelo rio Amazonas e pela Zona de Convergência Intertropical, e processos antrópicos associados à bubalinocultura. A análise foi realizada aplicando-se dados de satélite (JERS-1, RADARSAT-1, Landsat 7 e DEM do SRTM) digitalmente processados em abordagem multisensor, multiescala e multitemporal, correlacionada com dados pretéritos e informações de campo. A análise dos produtos gerados e dados colaterais permitiu distinguir oito padrões de uso e cobertura do solo: florestas de mangue, florestas de várzeas, campos arbustivos, áreas de vegetação campestre, campo antrópico, zona de intermaré, canal estuarino e lagos, além de feições morfológicas lineares associadas a estes padrões. Estas informações são importantes para o mapeamento dos ambientes costeiros e fundamentais para o reconhecimento da dinâmica na região.