(Virtual) Agents for running electricity markets

This paper describes a multi-agent based simulation (MABS) framework to construct an artificial electric power market populated with learning agents. The artificial market, named TEMMAS (The Electricity Market Multi-Agent Simulator), explores the integration of two design constructs: (i) the specification of the environmental physical market properties and (ii) the specification of the decision-making (deliberative) and reactive agents. TEMMAS is materialized in an experimental setup involving distinct power generator companies that operate in the market and search for the trading strategies that best exploit their generating units' resources. The experimental results show a coherent market behavior that emerges from the overall simulated environment.

Basis invariant conditions for supersymmetry in the two-Higgs-doublet model

The minimal supersymmetric standard model involves a rather restrictive Higgs potential with two Higgs fields. Recently, the full set of classes of symmetries allowed in the most general two-Higgs-doublet model was identified; these classes do not include the supersymmetric limit as a particular class. Thus, a physically meaningful definition of the supersymmetric limit must involve the interaction of the Higgs sector with other sectors of the theory. Here we show how one can construct basis invariant probes of supersymmetry involving both the Higgs sector and the gaugino-Higgsino-Higgs interactions.

A televisão na era digital: qual o modelo mais adequado para o serviço público de televisão na plataforma internet?

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

Constructing good deals in discrete time arbitrage-free dynamic pricing models

Recent literature has proved that many classical pricing models (Black and Scholes, Heston, etc.) and risk measures (V aR, CV aR, etc.) may lead to “pathological meaningless situations”, since traders can build sequences of portfolios whose risk leveltends to −infinity and whose expected return tends to +infinity, i.e., (risk = −infinity, return = +infinity). Such a sequence of strategies may be called “good deal”. This paper focuses on the risk measures V aR and CV aR and analyzes this caveat in a discrete time complete pricing model. Under quite general conditions the explicit expression of a good deal is given, and its sensitivity with respect to some possible measurement errors is provided too. We point out that a critical property is the absence of short sales. In such a case we first construct a “shadow riskless asset” (SRA) without short sales and then the good deal is given by borrowing more and more money so as to invest in the SRA. It is also shown that the SRA is interested by itself, even if there are short selling restrictions.

Visual Screening Competencies Questionnaire (VSCQ) and orthoptic practice

The identification of core competencies which are important for undertaking accurate visual screening by orthoptists is considered in this study. The aim was to construct and validate a questionnaire for orthoptists to assess visual screening competency. This study comprised three steps. The first step involved a 69-item self-assessment questionnaire constructed to assess orthoptists' perception of their competencies in visual screening programs for children. This questionnaire was constructed with statements from the Orthoptic Benchmark Statement for Health Care Programmes (Quality Assurance Agency for Higher Education, UK) and included three competency dimensions: interpersonal (IP), instrumental (IT) and systemic (ST). The second step involved questionnaire translation.

Dispositional optimism is unidimensional or bidimensional? The Portuguese Revised Life Orientation Test

The aim of the study is to adapt and then discuss the appropriateness of the Life Orientation Test as a one or two dimension scale. The research includes two studies; one is composed of a sequential sample of 280 people with multiple sclerosis, 71% female, and another includes a convenience sample of 615 individuals from the community, 51.1% female. Because the construct is built upon a theoretical assumption that has one dimension, we examine the hypothesis of one or two factor solutions through confirmatory factor analysis, and the two-dimension solution premise demonstrates better adjustment for both samples. The other psychometric properties explored show appropriate results for the Portuguese sample, and similar to the original ones; the Test therefore seems appropriate for use in cross cultural studies. Based on our results, we discuss whether the questionnaire is a one or two dimension instrument, concluding that it appears appropriate to accept the recommendations of the original authors to use it as a one-dimensional tool and, when necessary, to use both dimensions. - RESUMO: El objetivo del estudio es adaptar y discutir la adecuación de la prueba de Orientación de la Vida en una o dos escalas de dimensión. La investigación engloba dos estudios, uno constituido por una muestra secuencial de 280 personas con esclerosis múltiple, 71% mujeres y otro con una muestra de conveniencia de la comunidad de 615 individuos, 51,1% del sexo femenino. Como el constructo se asienta sobre la presunción teórica de que tiene una dimensión, inspeccionamos la hipótesis de una o dos soluciones de factor a través del análisis factorial confirmatorio y la hipótesis de dos dimensiones manifiesta un mejor ajuste para ambas muestras. Las otras propiedades psicométricas exploradas muestran los resultados apropiados para la muestra portuguesa, y semejantes a los originales. Parece apropiado para los estudios culturales transversales. Basándonos en nuestros resultados, discutimos si el cuestionario es un instrumento de una o dos dimensiones, concluyéndose que parece conveniente seguir las recomendaciones de los autores originales, para utilizarlo como un instrumento unidimensional y, si fuera necesario necesario, utilizar cada una de las dimensiones.

On the monoids of transformations that preserve the order and a uniform partition

In this article we consider the monoid O(mxn) of all order-preserving full transformations on a chain with mn elements that preserve a uniformm-partition and its submonoids O(mxn)(+) and O(mxn)(-) of all extensive transformations and of all co-extensive transformations, respectively. We determine their ranks and construct a bilateral semidirect product decomposition of O(mxn) in terms of O(mxn)(-) and O(mxn)(+).

Programa de manutenção de aeronaves das companhias de aviação de baixo custo

Este trabalho aborda o Programa de Manutenção de Aeronaves das companhias de aviação de baixo custo, tendo como foco a análise e identificação dos requisitos legais e das metodologias de desenvolvimento de um Programa de Manutenção de uma aeronave e a comparação dos custos de manutenção de companhias de baixo custo com as companhias regulares. A aplicação eficaz de um programa de manutenção, para além de reduzir os seus custos, tem um impacto positivo na segurança, economia da manutenção e na fiabilidade de despacho. A metodologia utilizada foi a análise de informação de publicações e artigos. Com base na revisão de literaturas especializadas, fez-se uma selecção dos diversos aspectos necessários para se obter um Programa de Manutenção, o que permitiu construir o caso de estudo e efectuar a análise dos custos inerentes de manutenção de um operador aéreo de baixo custo e de um operador aéreo regular. Os resultados da análise permitiram chegar a veracidade da hipótese de que do ponto de vista de manutenção é igualmente seguro ou não seguro voar numa companhia de baixo custo e numa companhia regular, assim independentemente do tipo de companhia, ambas devem cumprir os requisitos para aprovação do PMA imposto pela autoridade aeronáutica, para garantir a aeronavegabilidade das aeronaves, ou seja, a sua segurança para a condição de voo, sem pôr em causa o carimbo baixo custo ou regular da companhia.

Children's metalinguistic activity in the construction of linguistic existence

In this paper we examine the construction of first entities in narratives produced by children of 5, 7, 10 years and adults1 . The study demonstrates that when children reformulate they try to construct entities detached from the situation of enunciation, which means that they construct a detached or a translated plane and they construct linguistic existence of entities. Entities must first be introduced into the enunciative space and then comments will be made in subsequent utterances. Constructing existence supposes extraction. This consists of “singling out an occurrence, that is, isolating and drawing its spatiotemporal boundaries” (Culioli, 1990, p. 182) . Once the occurrence of the notion is constructed (which means it has become a separate occurrence with situational properties), children can predicate about it. However, there are children who do not construct the linguistic existence of entities. I hypothesize that the mode of task presentation influences the success of constructing linguistic existence. Sharing the investigator’s knowledge about the stimulus images, children do not ascribe an existential status to the occurrence of the notional domain.

Natureza, princípios e fundamentos das práticas e relações profissionais-doentes no contexto do Gabinete de Sub-visão do Instituto Dr. Gama Pinto

A institucionalização do direito à saúde, na constituição de 1976, como direito social e humano não parece ter conseguido, na prática dos profissionais de saúde, abalar a relação paternalista que coloca o doente numa situação de submissão face à dominância do poder/saber médico central ou periférico que o doente, nos termos de Parsons, deve acatar humildemente como “um bom doente”. É este papel de passividade e submissão do doente que nos propomos problematizar nos meandros dos direitos humanos/direitos sociais de cidadania como campo de construção social assente em práticas norteadas por direitos e deveres que, nos termos de Foucault, submetem os cidadãos a constrangimentos inerentes às relações de poder.

Os (in)sofismáveis caminhos do storytelling : Woody Allen e o documentário ficcionado

ABSTRACT: Between pure documentary and pure fiction there are, more and more, a reasonable number of cinematic alternatives that convey a dimension of non-reality. Between the pointedly factual discourse and the irrational belief in an entirely narrative world, there intervenes an informed conviction in a truthful but nonexistent universe, in which the formal enunciation sells an image of objectivity. In a path that leads us from the forms and contents of reflexive and performative documentaries, according to Bill Nichols, and ends up in fake documentary itself, we will have the opportunity to stress the filmic construction and its inherent narrative purpose, be it a fictional story or the creator himself as character (others would say subject) of the cinematic construct. In a boomerang kind of logic, the more the objects direct us to a referent, the more they restore us a creative/authorial reference and, along with it, the narrative idea that instills it. In Woody Allen’s case, this storytelling manifests itself in the fake documentary genre, which works as if it is the reality, only to better manifest the sole reality that interests the director: that of the metacinema, or the cinema as self-referencial reality. The practical examples will be derived from the following films: Take the Money and Run (1969) e Husbands and Wives (1992).

Optimização do posicionamento de câmaras de vídeo-vigilância

Dissertação de Mestrado em Engenharia de Redes de Comunicação e Multimédia

Modelo de data mining para detecção de tumores em exames de rastreio

Dissertação para obtenção do grau de Mestre em Engenharia Informática

The hospital survey on patient safety culture in Portuguese hospitals: instrument validity and reliability

Purpose – Quantitative instruments to assess patient safety culture have been developed recently and a few review articles have been published. Measuring safety culture enables healthcare managers and staff to improve safety behaviours and outcomes for patients and staff. The study aims to determine the AHRQ Hospital Survey on Patient Safety Culture (HSPSC) Portuguese version's validity and reliability. Design/methodology/approach – A missing-value analysis and item analysis was performed to identify problematic items. Reliability analysis, inter-item correlations and inter-scale correlations were done to check internal consistency, composite scores. Inter-correlations were examined to assess construct validity. A confirmatory factor analysis was performed to investigate the observed data's fit to the dimensional structure proposed in the AHRQ HSPSC Portuguese version. To analyse differences between hospitals concerning composites scores, an ANOVA analysis and multiple comparisons were done. Findings – Eight of 12 dimensions had Cronbach's alphas higher than 0.7. The instrument as a whole achieved a high Cronbach's alpha (0.91). Inter-correlations showed that there is no dimension with redundant items, however dimension 10 increased its internal consistency when one item is removed. Originality/value – This study is the first to evaluate an American patient safety culture survey using Portuguese data. The survey has satisfactory reliability and construct validity.

As representações e práticas sobre a segurança e saúde no trabalho: o caso dos trabalhadores do município de Albufeira

Mestrado em Segurança e Higiene no Trabalho