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Search Results: 1 - 10 of 34336 matches for " Pedro; Ferreira "
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Cosmic Strings in an Open Universe with Baryonic and Non-Baryonic Dark Matter
Pedro Ferreira
Physics , 1994, DOI: 10.1103/PhysRevLett.74.3522
Abstract: We study the effects of cosmic strings on structure formation in open universes. We calculate the power spectrum of density perturbations for two class of models: one in which all the dark matter is non baryonic (CDM) and one in which it is all baryonic (BDM). Our results are compared to the 1 in 6 IRAS QDOT power spectrum. The best candidates are then used to estimate $\mu$, the energy per unit length of the string network. Some comments are made on mechanisms by which structures are formed in the two theories.
Utiliza??o do SF-6D na medi??o das preferências dos portugueses: sistema de valores e normas da popula??o dos 18 aos 64 anos
Ferreira,Lara; Ferreira,Pedro;
Revista Portuguesa de Saúde Pública , 2011,
Abstract: introduction: there has been an increasing interest in the study of the health state valuations across countries. evidence suggests that health state valuations may differ from country to country. in recent years there has been increasing interest in surveys conducted to obtain value sets for the most used preference-based instruments, such as the eq-5d, the hui and the sf-6d. a portuguese value set for the sf-6d was recently published. however this system weight had some inconsistencies in what concerned the weights of the six dimensions of the sf-6d. the correction of these inconsistencies would improve the value set. this study seeks to present the portuguese system weight for the sf-6d without inconsistencies. it also aims at providing portuguese norms for individuals aged 18-64 for the sf-6d. methods: inconsistencies were found in some levels of the dimensions of the sf-6d. these levels were aggregated and parsimonious models were estimated through generalized estimating equations. the data used to obtain the portuguese norms for individuals aged 18-64 came from a random sample of the portuguese population aged 18-64 (n=2,459). the sf-36v2 was applied to this sample and results from the best parsimonious model were used to obtain the portuguese norms for individuals aged 18-64. results: aggregating levels of each dimension whenever inconsistencies occurred enabled to obtain a portuguese system weight for the sf-6d. however there are still some problems of under prediction in some states assigned to poor health. the mean utility value obtained for the portuguese working age population was 0.81 (associated with a standard deviation of 0.12). portuguese norms for the sf-6d for individuals aged 18-64 were computed by gender, age, marital status and educational level. lower levels of utilities were observed in women, the elderly, individuals with low educational level, widowed and individuals living in rural areas. conclusion: this research demonstrates that it is p
Productivity Monitoring of Land Pipelines Welding via Control Chart Using the Monte Carlo Simulation  [PDF]
Pedro Mattos Tabim, Miguel Luiz Ribeiro Ferreira
Journal of Software Engineering and Applications (JSEA) , 2015, DOI: 10.4236/jsea.2015.810051
Abstract: This article evaluates the efficacy of a tool developed in the Monte Carlo simulation and referred to as control chart. This tool is used in order to detect changes in productivity resulting from the occurrence of a given event during the welding of land pipelines with self shielded flux cored wire (FCAW). The elaboration of this control chart is based on the data from the Cumulative Probability Density Function (CDF) curve, and generated in the Monte Carlo simulation using version 6 of the Palisade Corporation’s @Risk software for Excel, in a sample with productivity data from 29 welded joints, gathered through direct observation which considers the productive and unproductive times. In order to evaluate the control chart efficacy, the performance of welding productivity with a FCAW process with low alloy steels has been assessed during 29 days, summing up to 842 welded joints registered on “Relatórios Diários de Obras” (Construction Works Daily Reports). The results show that the model developed for the control chart elaboration is effective in monitoring the productivity of the observed welding procedure.
Sobre a inexistente rela??o entre política industrial e comércio exterior
Ferreira, Pedro Cavalcanti;
Economia Aplicada , 2005, DOI: 10.1590/S1413-80502005000400001
Abstract: in contrast to the international literature, in brazil, the defense of public intervention for the promotion of industrial activity is very often associated to the improvement of our external accounts. this article exa-mines possible links between trade policy and industrial policy. it discusses the rationality of macro and micro arguments and shows that, in the one hand, there is serious theoretical and logical flaws in the defense of industrial policy as a devise to increase trade surplus. on the other hand, from the micro standpoint, there is no firm evidence supporting this type of intervention and the theoretical arguments do not apply. the article also studies the international experience and argues that it is doubtful if the fast growth and the expansion of the flow of international trade observed in korea, for instance, were caused by industrial policy.
Transe maquínico: quando som e movimento se encontram na música eletr?nica de pista
Ferreira, Pedro Peixoto;
Horizontes Antropológicos , 2008, DOI: 10.1590/S0104-71832008000100008
Abstract: since its historical emergence in the mid-70's, electronic dance music (edm) has always had as its main objective to make people dance by reproducing the right sounds at the right moments and in the right manner. notwithstanding the growing interest of researchers from diverse fields in the study of subjects related to edm, there is a noticeable tendency to reduce it to ideas and concepts originally forged for the study of musical styles not based on dance. this article will try to point out some problems brought up by this tendency and also suggest alternatives to it, with special attention to the sound-movement relation in machinic trance.
Controlo e identidade: a n?o conformidade durante a adolescência
Ferreira,Pedro Moura;
Sociologia, Problemas e Práticas , 2000,
Abstract: a análise sociológica sobre o desvio dos jovens tem sido desenvolvida em torno de dois modelos: o do "controlo" e o da "subcultura". o confronto entre os dois modelos n?o poderá deixar de notar que o olhar que tra?am sobre o desvio na adolescência coloca aparentemente um dilema: o desvio é resultante de um colapso das estruturas de autoridade e de controlo social ou constitui uma resposta a problemas com que os jovens se confrontam no processo de constru??o das suas identidades sociais? o desvio ocorre devido ao facto de os jovens n?o serem suficientemente controlados? ou deve ser entendido como uma resposta às tens?es entre um estatuto de dependência e o desejo de autonomia? a oposi??o dualista das quest?es n?o obriga a que as respostas sejam necessariamente exclusivas. certamente os dois modelos têm capacidade heurística. mas tal n?o significa que a influência por eles exercida seja a mesma ou que um n?o possa assumir primazia em determinadas situa??es (e problemas), n?o impedindo que noutras aconte?a o inverso. assim, mais do que procurar estabelecer a primazia de um em rela??o ao outro, o que motiva o presente artigo é dar conta de uma via de articula??o entre as dimens?es relevantes dos dois modelos, cuja adequa??o à realidade possa ser empiricamente confrontada e avaliada.
Tendências e modalidades da conjugalidade
Ferreira,Pedro Moura;
Sociologia, Problemas e Práticas , 2003,
Abstract: in the development of conjugality during the 1990s there are three fundamental aspects that registered important changes, that is, the number of people living as part of a couple, co-habitation and re-constituted families. between the two censuses of 1991 and 2001 the number of couples increased, in particular those without children. this rise also extended to couples that co-habit or re-constitute a family, although the former have increased more significantly than the latter. the analysis also allows the presentation of certain factors that have an impact on conjugal configurations at a given moment: the presence or absence of children, age, education, the occupational and professional situation and regional differences. the circumstances that make up these variables sometimes reinforce marriage and other times co-habitation.
Associa??es e democracia: Faz o associativismo alguma diferen?a na cultura cívica dos jovens portugueses?
Ferreira,Pedro Moura;
Sociologia, Problemas e Práticas , 2008,
Abstract: the goal of this article is to explore the impact of participation in associations on the civic culture of portuguese youth. the analysis essentially gives priority to two aspects. the first considers the distinguishing effect of belonging to associations on ?virtues? and civic skills and seeks to connect this effect with other structural properties. the second aspect contemplates the socialisation effect provided by the type of association membership, that is, it evaluates how far association activities produce unequal developments in terms of the civic culture of the youth. the empirical basis is the result of extensive research by questionnaire on a representative sample of portuguese youth, involving a thousand people.
Reliable disturbance rejection
Ferreira, Pedro M. G.;
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2005, DOI: 10.1590/S0103-17592005000100006
Abstract: the paper studies the reliability (sensor and actuator failures) of the asymptotic disturbance rejection problem for linear time invariant systems using the factorization approach, assuming that not all loops fail simultaneously and that sensor and actuator do not fail simultaneously. the plant is two-output, i.e. two-vector-output, and the disturbance is at the measured output of the plant. necessary and sufficient conditions are presented for the general problem and a simple solution is given for problems with stable plants.
Observing the temperature of the Big Bang through large scale structure
Ferreira, Pedro;Magueijo, Joao
High Energy Physics - Phenomenology , 2007, DOI: 10.1103/PhysRevD.78.061301
Abstract: It is widely accepted that the Universe underwent a period of thermal equilibrium at very early times. One expects a residue of this primordial state to be imprinted on the large scale structure of space time. In this paper we study the morphology of this thermal residue in a universe whose early dynamics is governed by a scalar field. We calculate the amplitude of fluctuations on large scales and compare it to the imprint of vacuum fluctuations. We then use the observed power spectrum of fluctuations on the cosmic microwave background to place a constraint on the temperature of the Universe before and during inflation. We also present an alternative scenario where the fluctuations are predominantly thermal and near scale-invariant.
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