Mapeamento da Investigação e Desenvolvimento na União Europeia

A Investigação e Desenvolvimento (I&D) tem um papel fundamental nos dias de hoje pois é a base da Inovação, do Conhecimento e do Desenvolvimento Tecnológico.

Modelling health state preference data using fixed and random effects models

The use of preference-based measures of health in the measurement of Health Related Quality of Life has become widely used in health economics. Hence, the development of preference-based measures of health has been a major concern for researchers throughout the world. This study aims to model health state preference data using a new preference-based measure of health (the SF- 6D) and to suggest alternative models for predicting health state utilities using fixed and random effects models. It also seeks to investigate the problems found in the SF-6D and to suggest eventual changes to it.

Small area estimation using linear mixed models with heterogeneous covariance structures of random effects

The problem of Small Area Estimation is about how to produce reliable estimates of domain characteristics when the sample sizes within the domain is very small ou even zero.

Small Area Estimation of the Mean Price of the Habitation Transaction in Portugal: Methodological and Practical Issues

The Portuguese National Statistical Institute intends to produce estimations for the mean price of the habitation transation.

Identificação das características dos clientes associadas ao risco de crédito

O processo da tomada de decisão sobre a avaliação de uma solicitação de crédito comercial é por vezes difícil para o julgamento humano, devido à imensidão de variáveis que estão em jogo e das suas inter- relações. Neste artigo propomo-nos identificar as características dos clientes associadas a alto e a baixo risco, com recurso a um modelo aplicacional. A partir de uma base de dados de um cartão de crédito, formada por variáveis de natureza qualitativa e quantitativa, ajustámos um modelo logit binário, com o objectivo de tornar o processo de decisão mais objectivo e quantificável. Em seguida, identificámos oito classes de risco através da aplicação de um método de classificação não hierárquica (K-means) sobre o vector da pontuação do modelo logit. Aferimos temporalmente o comportamento de cada classe de risco ao longo de 70 meses, verificando-se que probabilidades baixas de default estão associadas a classes de risco baixo. As características dos clientes tipicamente associadas ao risco de crédito foram identificadas através de uma Análise Factorial das Correspondências.

Evaluation of fruit and seed diversity and characterization of carob (Ceratonia siliqua L.) cultivars in Algarve region

The genetic diversity of 15 carob ( Ceratonia siliqua L.) cultivars located in an experimental field from Algarve (Portugal) was evaluated over 7 years using 12 fruit and seed phenotypic characters, in order to characterize carob cultivars. The values of morphological traits obtained by cultiv ar were compared with those from other countries of the Mediterranean basin. Statistically significant differences were found between cultivars for al l characters which were examined, what indicates a high genetic diversity. The relationship among these characters was analyzed by principal component analysis (PCA) resulting in the separation of these cultivars classed in four groups (clusters I–IV) and in four ungrouped cultivars. A three dimension of the model was found to be significant and explained 74.5% of the total variation, in which the first component accounting for 34.6% of the total variation is dominated by fruit characters, while the second component is dominated by seed characters. Cultivars plotted on the left-lower quadrant on the space determined by principal components 1 and 2 are characterized by fruits with high seed yield more appropriated for industrial rentability. The correlation analyses established by cultivar provided a specific understanding about the way how fruit and seed characteristics correlate within each cultivar. This approach can be useful for the development of a breeding programme, aiming to increase the seed yield, seed thickness, individual and total seed weight by fruit, characteristics that are determinant to improve the industrial exploitation of carob.

Methylamine as true template and TEAOH as purifying agent: unexpected roles of current organic additives in the hydrothermal synthesis of microporous aluminophosphates

Methylamine (MA), TEA+ and water were shown to play a concerted role during the synthesis of two new aluminophosphates IST-1 and IST-2. Both structures start to nucleate after the dramatic change of the gel composition due to preliminary interactions between TEA+ cations.

Unusual framework stabilization of Cu(II) and Cu(I) ions in a novel copper-substituted aluminophosphate with AEN topology prepared by one pot synthesis

A novel copper-substituted aluminophosphate (CuIST-2) has been synthesized using methylamine as a templating agent. X-Ray diffraction studies provide evidence for an AEN topology similar to the parent Cu-free IST-2.

Image morphology: from perception to rendering

Complete image ontology can be obtained by formalising a top-down meta-language wich must address all possibilities, from global message and composition to objects and local surface properties.