184 research outputs found
Calibration of transition intensities for a multistate model: Application to long-term care
UID/MAT/00297/2020We consider a non-homogeneous continuous time Markov chain model for Long-Term Care with five states: the autonomous state, three dependent states of light, moderate and severe dependence levels and the death state. For a general approach, we allow for non null intensities for all the returns from higher dependence levels to all lesser dependencies in the multi-state model. Using data from the 2015 Portuguese National Network of Continuous Care database, as the main research contribution of this paper, we propose a method to calibrate transition intensities with the one step transition probabilities estimated from data. This allows us to use non-homogeneous continuous time Markov chains for modeling Long-Term Care. We solve numerically the Kolmogorov forward differential equations in order to obtain continuous time transition probabilities. We assess the quality of the calibration using the Portuguese life expectancies. Based on reasonable monthly costs for each dependence state we compute, by Monte Carlo simulation, trajectories of the Markov chain process and derive relevant information for model validation and premium calculation.publishersversionpublishe
THE USE OF SIMILARITY IMAGES ON MULTI-SENSOR AUTOMATIC IMAGE REGISTRATION
Automatic image registration (AIR) is still a present challenge regarding remote sensing applications. Although several methods have been proposed in the last few years, geometric correction is often a time and effort consuming manual task. The only AIR method which is commonly used is the correlation-based template matching method. It usually consists on considering a window from one image and passing it throughout the other, looking for a maximum of correlation, which may be associated to the displacement between the two images. This approach leads sometimes (for example with multi-sensor image registration) to low correlation coefficient values, which do not give sufficient confidence to associate the peak of correlation to the correct displacement between the images. Furthermore, the peak of correlation is several times too flat or ambiguous, since more than one local peak may occur. Recently, we have tested a new approach, which shortly consists on the identification of a brighter diagonal on a "similarity image". The displacement of this brighter diagonal to the main diagonal corresponds to the displacement in each axis. In this work, we explored the potential of using the "similarity images" instead of the classical "similarity surface", considering both correlation coefficient and mutual information measures. Our experiments were performed on some multi-sensor pairs of images with medium (Landsat and ASTER) and high (IKONOS, ALOS-PRISM and orthophotos) spatial resolution, where a subpixel accuracy was mostly obtained. It was also shown that the application of a low-pass filtering prior to the similarity measures computation, allows for a significant increase of the similarity measures, reinforcing the strength of this methodology in multi-spectral, multi-sensor and multi-temporal situations
Leitura da identidade territorial: uma metodologia de análise a partir do estudo de caso de Almada na área metropolitana de Lisboa
A globalização econômica e o crescimento do turismo leva regiões e cidades de características variadas a planejar e implementar estratégias para competir, seja para atrair e fixar recursos e talentos humanos ou se impulsionar como destino turístico. A promoção das cidades e territórios utiliza a valorização de seus elementos distintivos para alcançar um impacto positivo no mercado global. Neste sentido, a identidade local pode ser potencializada enquanto valor intrínseco em consonância com o desenvolvimento socioeconômico da comunidade local. Com o objetivo de se realizar um diagnóstico que identifique os elementos distintivos e contenha informação crítica para a dinamização e desenvolvimento do território, recorreu‐se a uma leitura multidimensional do território, a partir de diferentes formas de relação e prática com o mesmo, através da aplicação de uma abordagem multimétodo. O estudo de caso piloto incidiu no território compreendido pelo Eixo Cacilhas ‐ Almada Velha ‐ Cristo Rei, localizado em Almada, parte da Área Metropolitana de Lisboa. Os resultados obtidos revelam as narrativas sobre o território por diferentes pontos de vista. Os elementos indicados como distintivos são associados à paisagem, à história, às memórias, à cultura e à forma urbana.info:eu-repo/semantics/publishedVersio
Lack of gene-language correlation due to reciprocal female but directional male admixture in Austronesians and non-Austronesians of East Timor
Analysis of paternal lineages in Brazilian and African populations
The present-day Brazilian population is a consequence of the admixture of various peoples of very different origins, namely, Amerindians, Europeans and Africans. The proportion of each genetic contribution is known to be very heterogeneous throughout the country. The aim of the present study was to compare the male lineages present in two distinct Brazilian populations, as well as to evaluate the African contribution to their male genetic substrate. Thus, two Brazilian population samples from Manaus (State of Amazon) and Ribeirão Preto (State of São Paulo) and three African samples from Guinea Bissau, Angola and Mozambique were typed for a set of nine Y chromosome specific STRs. The data were compared with those from African, Amerindian and European populations. By using Y-STR haplotype information, low genetic distances were found between the Manaus and Ribeirão Preto populations, as well as between these and others from Iberia. Likewise, no significant distances were observed between any of the African samples from Angola, Mozambique and Guinea Bissau. Highly significant Rst values were found between both Brazilian samples and all the African and Amerindian populations. The absence of a significant Sub-Saharan African male component resulting from the slave trade, and the low frequency in Amerindian ancestry Y-lineages in the Manaus and Ribeirão Preto population samples are in accordance with the accentuated gender asymmetry in admixture processes that has been systematically reported in colonial South American populations
Simulaçao numérica da dispersao de poluentes emitidos por incendios no verao de 2003 na Peninsula Ibérica
Ponencia presentada en: XXIX Jornadas Científicas de la AME y el VII Encuentro Hispano Luso de Meteorología celebrado en Pamplona, del 24 al 26 de abril de 2006.[PT]O objectivo deste trabalho é utilizar o modelo CATT-B-RAMS (Coupled Aerosol and Tracers Transport model to the Brazilian Regional Atmospheric Modeling System) para estudar o transporte atmosférico do monóxido de carbono (CO) e material particulado (PM2.5) emitidos por queimadas que ocorreram durante o Verão de 2003 na Península Ibérica, no período de 31 de Julho a 3 de Agosto com a situação sinóptica actuante na exportação destes poluentes. As simulações numéricas foram feitas com a assimilação dos dados de fogos derivados a partir de medidas do MODIS/AQUA para a Europa para implementar a posição da emissão. Para a caracterização do estado inicial do modelo foram usadas as análises do modelo global AVN/NCEP (Aviation run of the National
Center for Environmental Prediction Global Spectral Model) com grade de resolução de 80 km. Os resultados indicam que o modelo de mesoescala pode ser uma boa ferramenta para descrever a circulação atmosférica reproduzindo as principais características da situação sinóptica e o entendimento e avaliação deste impacto,
passam necessariamente, pela junção de estudos observacionais e modelação numérica gerando modelos complexos que descrevam as inter-relações biosfera-atmosfera, caracterizando um estudo multidisciplinar.[EN]This study presents the transport of gases and particulate emitted by large scale vegetation fires that took place in the Iberian Peninsula in summer of 2003. This study is carried out through a numerical simulation using a highresolution configuration of the 3-D transport model CATT-BRAMS (Coupled Aerosol and Tracer Transport to the Brazilian developments on the Regional Atmospheric Modeling System) coupled to a biomass burning emission model. The sources emission from biomass burning for carbon monoxide (CO) and particulate material (PM2.5)
are defined using MODIS/TERRA fire product and local observations. The initial and lateral boundary conditions necessary to drive model were provided by the Aviation run of the National Center for Environmental Prediction Global Spectral Model (AVN/NCEP). The coarse grid resolution was defined with 80 km grid spacing. The results show that the mesoscale model can be used as a useful tool to describe the atmospheric circulation reproducing
the main characteristics of the synoptic situation and how it controls the pollution transport
A new living lab for usability evaluation of ICT and next generation networks for elderly@home
Living Usability Lab for Next Generation Networks (www.livinglab.pt) is a Portuguese industry-academia collaborative R&D project, active in the field of live usability testing, focusing on the development of technologies and services to support healthy, productive and active citizens. The project adopts the principles of universal design and natural user interfaces (speech, gesture) making use of the benefits of next generation networks and distributed computing. Therefore, it will have impact on the general population, including the elderly and citizens with permanent or situational special needs. This paper presents project motivations, conceptual model, architecture and work in progress.info:eu-repo/semantics/acceptedVersio
Analysis of Y-chromosomal haplotypes and haplogroups distribution in a population sample from Portugal (central area)
Abstract. The aim of this study was to analyse the distribution of Y-chromosomal haplotypes and haplogroups found in central Portugal. In this work, we analysed 102 unrelated individuals of central Portugal. Combining the allelic state of 10 biallelic markers (YAP, SRY-8299, 92R7, 12f2, SRY-1532, SRY-2627, Tat, SY81, M9, LLY22g), we defined the haplogroup to which each sample belonged. Y-chromosomal haplotypes were defined by 16 Y-Short Tandem Repeats (STR) (DYS19, DYS385 a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460, DYS461, GATA A10, GATA C4 and GATA H4). This population study defined 8 different haplogroups and 101 different haplotypes, where 100 haplotypes were unique and 1 was found in two apparently unrelated individuals, both belonging to the same haplogroup.
Palaeolimnological evidence for an east-west climate see-saw in the Mediterranean since AD 900
During the period of instrumental records, the North Atlantic Oscillation (NAO) has strongly influenced inter-annual precipitation variations in the western Mediterranean, while some eastern parts of the basin have shown an anti-phase relationship in precipitation and atmospheric pressure. Here we explore how the NAO and other atmospheric circulation modes operated over the longer timescales of the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). High-resolution palaeolimnological evidence from opposite ends of the Mediterranean basin, supplemented by other palaeoclimate data, is used to track shifts in regional hydro-climatic conditions. Multiple geochemical, sedimentological, isotopic and palaeoecological proxies from Estanya and Montcortés lakes in northeast Spain and Nar lake in central Turkey have been cross-correlated at decadal time intervals since AD 900. These dryland lakes capture sensitively changes in precipitation/evaporation (P/E) balance by adjustments in water level and salinity, and are especially valuable for reconstructing variability over decadal-centennial timescales. Iberian lakes show lower water levels and higher salinities during the 11th to 13th centuries synchronous with the MCA and generally more humid conditions during the 'LIA' (15th-19th centuries). This pattern is also clearly evident in tree-ring records from Morocco and from marine cores in the western Mediterranean Sea. In the eastern Mediterranean, palaeoclimatic records from Turkey, Greece and the Levant show generally drier hydro-climatic conditions during the LIA and a wetter phase during the MCA. This implies that a bipolar climate see-saw has operated in the Mediterranean for the last 1100. years. However, while western Mediterranean aridity appears consistent with persistent positive NAO state during the MCA, the pattern is less clear in the eastern Mediterranean. Here the strongest evidence for higher winter season precipitation during the MCA comes from central Turkey in the northeastern sector of the Mediterranean basin. This in turn implies that the LIA/MCA hydro-climatic pattern in the Mediterranean was determined by a combination of different climate modes along with major physical geographical controls, and not by NAO forcing alone, or that the character of the NAO and its teleconnections have been non-stationary. © 2011 Elsevier B.V
Assimetrias regionais. Que diferenças nos estilos de vida e na satisfação com a vida dos adolescentes? Um estudo realizado em alunos do 3º ciclo do Ensino Básico em Portugal
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