798 resultados para Multi-scale hierarchical framework
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In this paper, a forward-looking infrared (FLIR) video surveillance system is presented for collision avoidance of moving ships to bridge piers. An image preprocessing algorithm is proposed to reduce clutter background by multi-scale fractal analysis, in which the blanket method is used for fractal feature computation. Then, the moving ship detection algorithm is developed from image differentials of the fractal feature in the region of surveillance between regularly interval frames. When the moving ships are detected in region of surveillance, the device for safety alert is triggered. Experimental results have shown that the approach is feasible and effective. It has achieved real-time and reliable alert to avoid collisions of moving ships to bridge piers.
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Obstacles considerably influence boundary layer processes. Their influences have been included in mesoscale models (MeM) for a long time. Methods used to parameterise obstacle effects in a MeM are summarised in this paper using results of the mesoscale model METRAS as examples. Besides the parameterisation of obstacle influences it is also possible to use a joint modelling approach to describe obstacle induced and mesoscale changes. Three different methods may be used for joint modelling approaches: The first method is a time-slice approach, where steady basic state profiles are used in an obstacle resolving microscale model (MiM, example model MITRAS) and diurnal cycles are derived by joining steady-state MITRAS results. The second joint modelling approach is one-way nesting, where the MeM results are used to initialise the MiM and to drive the boundary values of the MiM dependent on time. The third joint modelling approach is to apply multi-scale models or two-way nesting approaches, which include feedbacks from the MiM to the MeM. The advantages and disadvantages of the different approaches and remaining problems with joint Reynolds-averaged Navier–Stokes modelling approaches are summarised in the paper.
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We have extensively evaluated the response of cloud-base drizzle rate (Rcb; mm day–1) in warm clouds to liquid water path (LWP; g m–2) and to cloud condensation nuclei (CCN) number concentration (NCCN; cm–3), an aerosol proxy. This evaluation is based on a 19-month long dataset of Doppler radar, lidar, microwave radiometers and aerosol observing systems from the Atmospheric Radiation Measurement (ARM) Mobile Facility deployments at the Azores and in Germany. Assuming 0.55% supersaturation to calculate NCCN, we found a power law , indicating that Rcb decreases by a factor of 2–3 as NCCN increases from 200 to 1000 cm–3 for fixed LWP. Additionally, the precipitation susceptibility to NCCN ranges between 0.5 and 0.9, in agreement with values from simulations and aircraft measurements. Surprisingly, the susceptibility of the probability of precipitation from our analysis is much higher than that from CloudSat estimates, but agrees well with simulations from a multi-scale high-resolution aerosol-climate model. Although scale issues are not completely resolved in the intercomparisons, our results are encouraging, suggesting that it is possible for multi-scale models to accurately simulate the response of LWP to aerosol perturbations.
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Observations of atmospheric conditions and processes in citiesare fundamental to understanding the interactions between the urban surface and weather/climate, improving the performance of urban weather, air quality and climate models, and providing key information for city end-users (e.g. decision-makers, stakeholders, public). In this paper, Shanghai's urban integrated meteorological observation network (SUIMON) and some examples of intended applications are introduced. Its characteristics include being: multi- purpose (e.g. forecast, research, service), multi-function (high impact weather, city climate, special end-users), multi-scale (e.g. macro/meso-, urban-, neighborhood, street canyon), multi-variable (e.g. thermal, dynamic, chemical, bio-meteorological, ecological), and multi- platform (e.g. radar, wind profiler, ground-based, satellite based, in-situ observation/ sampling). Underlying SUIMON is a data management system to facilitate exchange of data and information. The overall aim of the network is to improve coordination strategies and instruments; to identify data gaps based on science and user driven requirements; and to intelligently combine observations from a variety of platforms by using a data assimilation system that is tuned to produce the best estimate of the current state of the urban atmosphere.
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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 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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In the past, the focus of drainage design was on sizing pipes and storages in order to provide sufficient network capacity. This traditional approach, together with computer software and technical guidance, had been successful for many years. However, due to rapid population growth and urbanisation, the requirements of a “good” drainage design have also changed significantly. In addition to water management, other aspects such as environmental impacts, amenity values and carbon footprint have to be considered during the design process. Going forward, we need to address the key sustainability issues carefully and practically. The key challenge of moving from simple objectives (e.g. capacity and costs) to complicated objectives (e.g. capacity, flood risk, environment, amenity etc) is the difficulty to strike a balance between various objectives and to justify potential benefits and compromises. In order to assist decision makers, we developed a new decision support system for drainage design. The system consists of two main components – a multi-criteria evaluation framework for drainage systems and a multi-objective optimisation tool. The evaluation framework is used for the quantification of performance, life-cycle costs and benefits of different drainage systems. The optimisation tool can search for feasible combinations of design parameters such as the sizes, order and type of drainage components that maximise multiple benefits. In this paper, we will discuss real-world application of the decision support system. A number of case studies have been developed based on recent drainage projects in China. We will use the case studies to illustrate how the evaluation framework highlights and compares the pros and cons of various design options. We will also discuss how the design parameters can be optimised based on the preferences of decision makers. The work described here is the output of an EngD project funded by EPSRC and XP Solutions.
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The identification of the factors that interfere in the decline of functional conditions is useful in the planning of actions addressing the improvement in the conditions of the lives of elderly people. The purpose of this investigation was to analyze the relationship between social demographics and health aspects of the functional condition in elderly women of low income of the Brazilian northeast. This crosssectional study involved a representative sample of 222 women with an average age of 70 years (± 7.1), belonging to coexisting groups and that were resident in the urban area of the municipal district of Jequié /Bahia. In order to achieve this objective, a battery of physical tests of functional aptitude was carried out previously tested in pilot study, anthropometric measurements collected with a comparison of the measures referred to the reported weight and height as well as the application of an interview with questions containing subjects related to social demographic variables, clinical conditions and health, physical conditions and behaviors. Descriptive statistics Proceedings (frequency, average, standard deviation and percent distribution) were used for statistic analysis, and the calculation of the respective odds ratio by binary logistics regression, for the analysis of factors hierarchically grouped; p<0.05. The prevalence of 56% (n=122) of women considered with moderated or serious type of functional limitations was found, In which from multi-varied hierarchical analysis, significant association was verified with the age group over 80 years (p=0.02), conditions of widowhood (p=0.04), presence of arterial hypertension (p=0.001), and physical inactivity during leisure time (p=0.03). On the other hand for functional incapacities the prevalence was of 46.8% (n=104) being associated to the increase of the age (p=0.01), hospitalization (p=0.02), absence of physical activities along their lives (p=0.001) and the occurrence of alterations in the cognitive function (p=0.001). The normative table for the parameters of physical fitness generated conducive to health professionals in the diagnosis of health conditions and the prescription of physical exercises. The identified characteristics that are associated with the functional limitations / functional incapacities suggest a complex causal net in the determination of the functional condition in elderly women. However, actions addressed to the incentive of the practice of physical activities in the leisure time and the preservation of the cognitive function can contribute to a life with more quality for these people. This research was multidisciplinary approach to involve elements of psychology, nutrition and Physical Education in the elucidation of the object of study related to the functional condition of elderly women
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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Ciências Cartográficas - FCT
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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.