Representing Roomates' Preferences with Symmetric Utilities

In the context of the stable roommates problem, it is shown that acyclicity of preferences is equivalent to the existence of symmetric utility functions, i.e. the utility of agent i when matched with j is the same as j 's utility when matched with i .

Portugal

During 2004, Portugal reversed the tendency of slow wind capacity growth observed in previous years. The publication of legislation and tariffs at the end of 2001 and subsequent government simplifi cation of administrative processes concerning the implementation of renewable energy projects resulted in nearly doubled capacity in Portugal during 2004. In the following sections, a summary of the events of the year is presented with a main focus on the current state of development and trends

Bronchial asthma in portuguese university students: study of prevalence and risk factors

Objectives – To determine the prevalence of asthma in Portuguese university students; to characterize their disease based on self-reported symptoms; and to identify possible risk factors for Asthma. Methods – In this observational cross-sectional study, a sample of 1000 students were randomly selected and given a questionnaire in order to determine the prevalence of bronchial asthma. From the students who were identified and gave their consent, 548 answered a questionnaire. Those whose answers were compatible with a probable diagnosis of bronchial asthma were contacted, via phone call, in order to assess their asthma control. Multivariate statistical analyses were conducted using logistic regressions models to determine potential risk factors. Results – A total of 578 students answered the questionnaire, and 121 were identified with self-reported symptoms compatible with asthma. Of these, 48.8% already had a previous diagnosis made by a doctor. 76% of the diagnosed students also had rhinitis. The triggers for asthma symptoms most reported by the students were common colds, exposure to pollens, house dust, tobacco smoke and weather changes. Of the students identified with self-reported asthma, 50.4% answered the phone call, and, of these, 62.3% had asthma symptoms that were not controlled in the previous month. From the factors potentially associated with increased risk of asthma, two of them significantly increased the risk of the disease: habits of regular smoking (OR = 2.09, 95%CI 1.21 to 3.62) and personal history of dermatitis/ atopic eczema (OR 2.65, 95%CI 1.55 to 4.54). Conclusions – The prevalence of asthma in university students in Beira Interior, Portugal, was 20.9%. Only 48.8% of them had a previous diagnosis made by a doctor. Of those who allowed us to assess their asthma control, 62.3% were not controlled, and that may be related to infrequent medical follow up. Regular smoking and personal history of dermatitis/atopic eczema significantly increased the risk of having bronchial asthma.Objetivos - Determinar a prevalência de asma brônquica em estudantes universitários portugueses; caracterizar a sua doença com base em sintomas auto reportados; identificar possíveis fatores de risco para a asma. Métodos – Neste estudo transversal observacional, uma amostra de 1000 alunos foi aleatoriamente selecionada para responder a um questionário de rastreio. O questionário foi entregue em papel, nas salas de aula, aos alunos identificados que deram o seu consentimento. Dos alunos identificados, 548 responderam ao questionário. Aqueles cujas respostas eram compatíveis com um provável diagnóstico de asma brônquica foram contactados, por via telefónica, com o objetivo de medir o controlo dos seus sintomas asmáticos no mês anterior. Para determinar potenciais fatores de risco de asma brônquica, foram efetuadas análises estatísticas multivariáveis, utilizando modelos de regressão logística. Resultados – Um total de 578 alunos respondeu ao questionário, e 121 alunos foram identificados com sintomas auto reportados compatíveis com o diagnóstico de asma brônquica. Desses, 48,8% já tinham sido diagnosticados como asmáticos por um médico, e 76% deles tinham também rinite. Os fatores desencadeantes de sintomas asmáticos mais identificados pelos estudantes foram corizas, exposição a pólenes, pó de casa, fumo de tabaco e variações climáticas. Dos estudantes identificados com sintomas compatíveis com o diagnóstico de asma, 50,4% atenderam a chamada telefónica, e, desses, 62,3% tinham sintomas asmáticos não controlados no mês anterior. Dos fatores de risco potencialmente associados a um aumento de risco de asma brônquica, constatou-se que dois aumentavam significativamente o risco de desenvolver asma: hábitos de tabagismo regular (OR = 2,09, 95% IC 1,21 a 3,62) e história pessoal de dermatite/ eczema atópico (OR 2,65, 95% IC 1,55 a 4,54). Conclusões – O valor de prevalência de asma brônquica nos estudantes universitários da Universidade da Beira Interior é de 20,9%. Destes, apenas 48,8% possuíam um diagnóstico prévio efetuado por um médico. Dos estudantes diagnosticados que nos permitiram medir o seu nível de controlo da asma, 62,3% não tinham os seus sintomas asmáticos controlados, podendo este facto estar relacionado com um irregular acompanhamento médico. Hábitos regulares de tabagismo e história pessoal de dermatite/eczema atópico aumentam significativamente o risco de asma brônquica

An Approach to Urban Quarter Design Using Building Generative Design and Thermal Performance Optimization

AbstractBuildings thermal performance is influenced by the urban context, such as adjacent buildings shadows, block wind paths, or solar radiation reflection. For this reason, in this paper, an automated procedure is used to generate and optimize buildings’ thermal performance in a closed O-shape urban quarter with ten building blocks to determine the importance of including the surroundings in estimating the buildings’ thermal behavior. The overall shape of the urban quarter is pre-designed, being mainly residential, with several stores in the ground floor and limited to three levels. Each building will have four alternative designs created using a hybrid evolutionary strategy technique that generates building's floor plans according to practitioner's preferences and requirements. Then, a sequential variable optimization procedure coupled with dynamic simulation engine is used to explore the improvement potential of each solution by changing and adding several building elements. The final quarter design is determined by combining the best of all buildings’ solutions from thermal performance criteria.The results demonstrate the influence of urban context in the resulting building's thermal performance. Despite the building's shape is similar in the four solutions, these have significant thermal behavior difference due to their interior organization and position in the urban quarter. A comparison analysis is carried out between all building block designs. The buildings, which have exterior walls with openings facing south, have almost half degree-hours of thermal discomfort due to the combination of large openings and shading overhangs. It is also possible to conclude that generative tools, enhanced with optimization procedures, may help practitioners in designing more energy efficient buildings