Framework for a business interoperability quotient measurement model

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova da Lisboa para obtenção do grau de Mestre em Engenharia e Gestão Industrial (MEGI)

Experimental design methodologies for the identification of Michaelis-Menten type kinetics

The main objective of this work was to investigate the application of experimental design techniques for the identification of Michaelis-Menten kinetic parameters. More specifically, this study attempts to elucidate the relative advantages/disadvantages of employing complex experimental design techniques in relation to equidistant sampling when applied to different reactor operation modes. All studies were supported by simulation data of a generic enzymatic process that obeys to the Michaelis-Menten kinetic equation. Different aspects were investigated, such as the influence of the reactor operation mode (batch, fed-batch with pulse wise feeding and fed-batch with continuous feeding) and the experimental design optimality criteria on the effectiveness of kinetic parameters identification. The following experimental design optimality criteria were investigated: 1) minimization of the sum of the diagonal of the Fisher information matrix (FIM) inverse (A-criterion), 2) maximization of the determinant of the FIM (D-criterion), 3) maximization of the smallest eigenvalue of the FIM (E-criterion) and 4) minimization of the quotient between the largest and the smallest eigenvalue (modified E-criterion). The comparison and assessment of the different methodologies was made on the basis of the Cramér-Rao lower bounds (CRLB) error in respect to the parameters vmax and Km of the Michaelis-Menten kinetic equation. In what concerns the reactor operation mode, it was concluded that fed-batch (pulses) is better than batch operation for parameter identification. When the former operation mode is adopted, the vmax CRLB error is lowered by 18.6 % while the Km CRLB error is lowered by 26.4 % when compared to the batch operation mode. Regarding the optimality criteria, the best method was the A-criterion, with an average vmax CRLB of 6.34 % and 5.27 %, for batch and fed-batch (pulses), respectively, while presenting a Km’s CRLB of 25.1 % and 18.1 %, for batch and fed-batch (pulses), respectively. As a general conclusion of the present study, it can be stated that experimental design is justified if the starting parameters CRLB errors are inferior to 19.5 % (vmax) and 45% (Km), for batch processes, and inferior to 42 % and to 50% for fed-batch (pulses) process. Otherwise equidistant sampling is a more rational decision. This conclusion clearly supports that, for fed-batch operation, the use of experimental design is likely to largely improve the identification of Michaelis-Menten kinetic parameters.

Fuzzy clustering não supervisionado na detecção automática de regiões de upwelling a partir de mapas de temperatura da superfície oceânica

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática

O impacto da variação do preço na procura de cuidados de saúde

RESUMO - Assiste-se a um crescimento exponencial das despesas em saúde, quer na Europa como nos Estados Unidos. Em Portugal, os gastos totais com a saúde ascenderam a 10,2% do PIB, em 2006, contra os 8,8% registados no início da década anterior. É importante perceber o que motiva este crescimento quer em termos globais, quer no que diz respeito ao consumo de recursos, bem como até em termos da despesa pública. Este projecto tem dois objectivos fundamentais: em primeiro lugar, contribuir para o estudo dos factores determinantes da procura de cuidados de saúde em Portugal e, consequentemente, determinar as elasticidades procura – preço para diferentes tipos de cuidados de saúde. Metodologia: Estudo observacional baseado na análise empírica de dados administrativos (claims) respeitantes à utilização dos cuidados de saúde por parte de 12.230 indivíduos detentores de um plano de seguro de saúde individual, numa seguradora privada em Portugal. As elasticidades procura – preço para os diferentes tipos de cuidados de saúde obtiveram-se utilizando as variações percentuais das quantidades dos diferentes cuidados de saúde, antes e depois da variação do preço pago pelo indivíduo, para cada tipo de cuidado de saúde. Resultados: De acordo com a teoria económica tradicional o aumento do preço a pagar reduz o consumo de cuidados de saúde, e a procura é elástica, ou seja, os valores da elasticidade procura – preço obtidos são superiores a 1, em valor absoluto, logo o aumento do preço levou a uma redução mais do que proporcional das quantidades procuradas. A procura de cuidados de saúde em ambulatório é mais sensível à variação do preço do que a procura de cuidados de internamento. ------- ABSTRACT - We are witnessing an exponential growth of health care expenditures around the world. In Portugal, the total expenditure on health amounted to 10.2% of GDP in 2006, against 8.8% at the beginning of previous decade. It is important to understand what motivates this growth both in overall terms, with respect to resource consumption, and even in terms of public spending. This study was designed two achieve two objectives: first, to contribute to the study of demand for health care and, more specifically, to analyze the effect of price changes on the utilization of health care services; and secondly, to estimate the demand elasticity for different types of heath care. Methodology: Observational study based on empirical analysis of administrative data (claims) from a private health insurance Company in Portugal. The sample used had information regarding 12.230 individuals. Demand elasticity for the different types of health care services was obtained by the quotient between the percentage changes in the quantity of health care services, before and after the change in the price paid by the corresponding percentage change in the price. Results: This study showed that, for all medical services, price increases were associated with reductions in the quantity of care consumed as predicted by neoclassical demand theory, and we are in the presence of an elastic demand. This means that price elasticity is greater than 1 in absolute value so the increase in the price led to a more than proportional reduction in the quantity demanded. Demand elasticity was more responsive to changes in the price of specialist and emergency care than to changes in the price of inpatient care.

Trace elements quantification in Portuguese red wines

Dissertation for the Degree of Master in Technology and Food Safety – Food Quality

Hydrologic modeling and uncertainty analysis of an ungauged watershed using mapwindow-swat

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies

Development of an integrative approach for the characterization of ecological risk on marine transition ecosystems: the Sado Estuary as a case study

Estuaries and other transitional waters are complex ecosystems critically important as nursery and shelter areas for organisms. Also, humans depend on estuaries for multiple socio-economical activities such as urbanism, tourism, heavy industry, (taking advantage of shipping), fisheries and aquaculture, the development of which led to strong historical pressures, with emphasis on pollution. The degradation of estuarine environmental quality implies ecologic, economic and social prejudice, hence the importance of evaluating environmental quality through the identification of stressors and impacts. The Sado Estuary (SW Portugal) holds the characteristics of industrialized estuaries, which results in multiple adverse impacts. Still, it has recently been considered moderately contaminated. In fact, many studies were conducted in the past few years, albeit scattered due to the absence of true biomonitoring programmes. As such, there is a need to integrate the information, in order to obtain a holistic perspective of the area able to assist management and decision-making. As such, a geographical information system (GIS) was created based on sediment contamination and biomarker data collected from a decade-long time-series of publications. Four impacted and a reference areas were identified, characterized by distinct sediment contamination patterns related to different hot spots and diffuse sources of toxicants. The potential risk of sediment-bound toxicants was determined by contrasting the levels of pollutants with available sediment quality guidelines, followed by their integration through the Sediment Quality guideline Quotient (SQG-Q). The SQG-Q estimates per toxicant or class was then subjected to georreferencing and statistical analyses between the five distinct areas and seasons. Biomarker responses were integrated through the Biomarkers Consistency Indice and georreferenced as well through GIS. Overall, in spite of the multiple biological traits surveyed, the biomarker data (from several organisms) are accordant with sediment contamination. The most impacted areas were the shipyard area and adjacent industrial belt, followed by urban and agricultural grounds. It is evident that the estuary, although globally moderately impacted, is very heterogeneous and affected by a cocktail of contaminants, especially metals and polycyclic aromatic hydrocarbon. Although elements (like copper, zinc and even arsenic) may originate from the geology of the hydrographic basin of the Sado River, the majority of the remaining contaminants results from human activities. The present work revealed that the estuary should be divided into distinct biogeographic units, in order to implement effective measures to safeguard environmental quality.