34 resultados para semi-parametric estimation
Resumo:
Ao longo dos Pensamentos, Pascal expressa a sua antipatia filosófica por alguns tipos de pensadores. Um desses tipos de pensadores corresponde à figura do "demi-savant". Os "demi-savants", ou semi-sábios, caracterizam-se essencialmente por uma pretensão de saber fracassada: são homens que julgam estar na posse de um saber que na verdade não possuem. O objectivo desta investigação é fixar, com o maior detalhe possível, o que está em causa na denúncia dos semi-sábios — um aspecto pouco trabalhado no âmbito dos estudos sobre o pensamento de Pascal. A primeira parte da investigação consiste assim na delimitação formal da categoria semi-sábios. Quais são as notas definitórias destes pensadores? Que tipo de erro está em jogo na sua atitude? Que opiniões fazem de alguém um semi-sábio? Estas perguntas acabam rapidamente por nos levar a outras, que dizem directamente respeito à tentativa de determinação do poder de fogo da razão humana. Com efeito, o fundamento filosófico da crítica aos semi-sábios é o diagnóstico arrasador que Pascal faz da capacidade da nossa razão na tarefa do conhecimento — de tal modo que estudar o problema que os semi-sábios representam é estudar sob um determinado ângulo o problema geral da procura da verdade. Nesse sentido, depois de esclarecido o significado da designação semi-sábio, analisamos dois argumentos apresentados nos Pensamentos que visam contestar a compreensão habitualmente constituída acerca das possibilidades do homem na tarefa do conhecimento. Procuramos ainda, por último, desfazer possíveis equívocos quanto à fixação da posição de Pascal no campo da epistemologia. Embora haja poucas referências aos semi-sábios nos textos que compõem os Pensamentos, trata-se de uma figura que funciona como ponto de cruzamento de vários aspectos relevantes de um problema que está no centro do projecto apologético de Pascal: o problema do modo de apuramento da verdade.
Resumo:
The aim of this work project is to analyze the current algorithm used by EDP to estimate their clients’ electrical energy consumptions, create a new algorithm and compare the advantages and disadvantages of both. This new algorithm is different from the current one as it incorporates some effects from temperature variations. The results of the comparison show that this new algorithm with temperature variables performed better than the same algorithm without temperature variables, although there is still potential for further improvements of the current algorithm, if the prediction model is estimated using a sample of daily data, which is the case of the current EDP algorithm.
Resumo:
The Electrohysterogram (EHG) is a new instrument for pregnancy monitoring. It measures the uterine muscle electrical signal, which is closely related with uterine contractions. The EHG is described as a viable alternative and a more precise instrument than the currently most widely used method for the description of uterine contractions: the external tocogram. The EHG has also been indicated as a promising tool in the assessment of preterm delivery risk. This work intends to contribute towards the EHG characterization through the inventory of its components which are: • Contractions; • Labor contractions; • Alvarez waves; • Fetal movements; • Long Duration Low Frequency Waves; The instruments used for cataloging were: Spectral Analysis, parametric and non-parametric, energy estimators, time-frequency methods and the tocogram annotated by expert physicians. The EHG and respective tocograms were obtained from the Icelandic 16-electrode Electrohysterogram Database. 288 components were classified. There is not a component database of this type available for consultation. The spectral analysis module and power estimation was added to Uterine Explorer, an EHG analysis software developed in FCT-UNL. The importance of this component database is related to the need to improve the understanding of the EHG which is a relatively complex signal, as well as contributing towards the detection of preterm birth. Preterm birth accounts for 10% of all births and is one of the most relevant obstetric conditions. Despite the technological and scientific advances in perinatal medicine, in developed countries, prematurity is the major cause of neonatal death. Although various risk factors such as previous preterm births, infection, uterine malformations, multiple gestation and short uterine cervix in second trimester, have been associated with this condition, its etiology remains unknown [1][2][3].
Resumo:
Ship tracking systems allow Maritime Organizations that are concerned with the Safety at Sea to obtain information on the current location and route of merchant vessels. Thanks to Space technology in recent years the geographical coverage of the ship tracking platforms has increased significantly, from radar based near-shore traffic monitoring towards a worldwide picture of the maritime traffic situation. The long-range tracking systems currently in operations allow the storage of ship position data over many years: a valuable source of knowledge about the shipping routes between different ocean regions. The outcome of this Master project is a software prototype for the estimation of the most operated shipping route between any two geographical locations. The analysis is based on the historical ship positions acquired with long-range tracking systems. The proposed approach makes use of a Genetic Algorithm applied on a training set of relevant ship positions extracted from the long-term storage tracking database of the European Maritime Safety Agency (EMSA). The analysis of some representative shipping routes is presented and the quality of the results and their operational applications are assessed by a Maritime Safety expert.