91 resultados para tightness


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This article argues that a native-speaker baseline is a neglected dimension of studies into second language (L2) performance. If we investigate how learners perform language tasks, we should distinguish what performance features are due to their processing an L2 and which are due to their performing a particular task. Having defined what we mean by “native speaker,” we present the background to a research study into task features on nonnative task performance, designed to include native-speaker data as a baseline for interpreting nonnative-speaker performance. The nonnative results, published in this journal (Tavakoli & Foster, 2008) are recapitulated and then the native-speaker results are presented and discussed in the light of them. The study is guided by the assumption that limited attentional resources impact on L2 performance and explores how narrative design features—namely complexity of storyline and tightness of narrative structure— affect complexity, fluency, accuracy, and lexical diversity in language. The results show that both native and nonnative speakers are prompted by storyline complexity to use more subordinated language, but narrative structure had different effects on native and nonnative fluency. The learners, who were based in either London or Tehran, did not differ in their performance when compared to each other, except in lexical diversity, where the learners in London were close to native-speaker levels. The implications of the results for the applicability of Levelt’s model of speaking to an L2 are discussed, as is the potential for further L2 research using native speakers as a baseline.

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Abstract Managers face hard choices between process and outcome systems of accountability in evaluating employees, but little is known about how managers resolve them. Building on the premise that political ideologies serve as uncertainty-reducing heuristics, two studies of working managers show that: (1) conservatives prefer outcome accountability and liberals prefer process accountability in an unspecified policy domain; (2) this split becomes more pronounced in a controversial domain (public schools) in which the foreground value is educational efficiency but reverses direction in a controversial domain (affirmative action) in which the foreground value is demographic equality; (3) managers who discover employees have subverted their preferred system favor tinkering over switching to an alternative system; (4) but bipartisan consensus arises when managers have clear evidence about employee trustworthiness and the tightness of the causal links between employee effort and success. These findings shed light on ideological and contextual factors that shape preferences for accountability systems.

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We study horo-tight immersions of manifolds into hyperbolic spaces. The main result gives several characterizations of horo-tightness of spheres, answering a question proposed by Cecil and Ryan. For instance, we prove that a sphere is horo-tight if and only if it is tight in the hyperbolic sense. For codimension bigger than one, it follows that horo-tight spheres in hyperbolic space are metric spheres. We also prove that horo-tight hyperspheres are characterized by the property that both of its total absolute horospherical curvatures attend their minimum value. We also introduce the notion of weak horo-tightness: an immersion is weak horo-tight if only one of its total absolute curvature attends its minimum. We prove a characterization theorem for weak horo-tight hyperspheres.

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We study the properties of the lower bound on the exchange-correlation energy in two dimensions. First we review the derivation of the bound and show how it can be written in a simple density-functional form. This form allows an explicit determination of the prefactor of the bound and testing its tightness. Next we focus on finite two-dimensional systems and examine how their distance from the bound depends on the system geometry. The results for the high-density limit suggest that a finite system that comes as close as possible to the ultimate bound on the exchange-correlation energy has circular geometry and a weak confining potential with a negative curvature. (c) 2009 Elsevier B.V. All rights reserved.

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In this project, Stora Enso’s newly developed building system has been further developed to allow building to the Swedish passive house standard for the Swedish climate. The building system is based on a building framework of CLT (Cross laminated timber) boards. The concept has been tested on a small test building. The experience gained from this test building has also been used for planning a larger building (two storeys with the option of a third storey) with passive house standard with this building system. The main conclusions from the project are:  It is possible to build airtight buildings with this technique without using traditional vapour barriers. Initial measurements show that this can be done without reaching critical humidity levels in the walls and roof, at least where wood fibre insulation is used, as this has a greater capacity for storing and evening out the moisture than mineral wool. However, the test building has so far not been exposed to internal generation of moisture (added moisture from showers, food preparation etc.). This needs to be investigated and this will be done during the winter 2013-14.  A new fixing method for doors and windows has been tested without traditional fibre filling between them and the CLT panel. The door or window is pressed directly on to the CLT panel instead, with an expandable sealing strip between them. This has been proved to be successful.  The air tightness between the CLT panels is achieved with expandable sealing strips between the panels. The position of the sealing strips is important, both for the air tightness itself and to allow rational assembly.  Recurrent air tightness measurements show that the air tightness decreased somewhat during the first six months, but not to such an extent that the passive house criteria were not fulfilled. The reason for the decreased air tightness is not clear, but can be due to small movements in the CLT construction and also to the sealing strips being affected by changing outdoor temperatures.  Long term measurements (at least two years) have to be carried out before more reliable conclusions can be drawn regarding the long term effect of the construction on air tightness and humidity in the walls.  An economic analysis comparing using a concrete frame or the studied CLT frame for a three storey building shows that it is probably more expensive to build with CLT. For buildings higher than three floors, the CLT frame has economic advantages, mainly because of the shorter building time compared to using concrete for the frame. In this analysis, no considerations have been taken to differences in the influence on the environment or the global climate between the two construction methods.

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Air tightness of Australian buildings is a great unknown. Despite testing methods being developed and implemented in many advanced European and North American countries, this has not happened in Australia. This paper notes energy efficiency gains that can be achieved through tighter construction, and follows on from the investigation into testing methodology and literature discussed in TEC 23: Air Leakage in Buildings – Review of International Literature and Standards. Several domestic case studies are used to implement two accepted testing methods and aid to build the case for increased awareness of airtight housing in Australia.

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 Thermal comfort models, as we know them today, have been available since the early 1970’s and have been applied to assess the conditioning of our buildings. What we have is a comfort value of an interior environment at a particular location as a result of several measured parameters. What we don’t often consider is how the building contributes to this resulting thermal environment and how occupants respond to its possible changes. The following research considers the climatic and comfort findings from 15 fully air conditioned office buildings between Brisbane and Melbourne Australia during brief seasonal periods of measurement. Initially, each office building
was considered as its own individual project; however the grouping of the results has led to some interesting observations:
Regardless of building type or whether there is a narrow controlled comfort band,
there can be a significant variation in the clothing level of occupants.
There is a greater exterior to interior air temperature correlation than might be expected among fully air-conditioned buildings. The diurnal ranges of interior temperatures (over 24 hours) may be far greater than anticipated. It is realised that fully conditioned buildings are far more variable than perhaps realised and that occupant comfort may relate more to user interaction (CLO value), building construction type (weight) and envelope air tightness. As a result, this investigation raises perhaps more questions than answers as to how we assess thermal comfort in
buildings.

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This paper describes properties of upper semi-continuous homothetic preferences. First we give conditions for the existence of an upper semi-continuous representation which is homogeneous of degree one. Then we show that with the additional assumptions of monotonicity or strict convexity, the preference is continuous. Several counterexamples illustrate the tightness of the results.

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A asma brônquica é uma doença crônica inflamatória das vias aéreas que vem despertando preocupação crescente, em função do aumento na sua incidência e mortalidade observados nos últimos anos. Com o objetivo principal de avaliar a sua prevalência e seus fatores de risco, conduziu-se um estudo epidemiológico de base populacional, delineamento transversal, em uma amostra representativa de adultos de 20 a 69 anos de idade, residentes na zona urbana de Pelotas, RS. Foram entrevistadas 1.968 pessoas. Desse total, 446 pessoas foram aleatoriamente selecionadas para realizarem espirometria e, quando esta mostrava-se normal, teste de broncoprovocação com metacolina. Ainda foram realizados testes para atopia. Houve 9,6% de recusas para as entrevistas e 20,2% de perdas para os exames complementares. Mais de metade da amostra era constituída por pessoas com idade inferior a 50 anos, sendo 57% do sexo feminino e a maioria da raça branca. A renda familiar, na maioria da amostra, era de até três salários mínimos. A prevalência de “sintomas atuais de asma” foi de 6,0%. Observou-se variação na prevalência de asma com a utilização de diferentes critérios diagnósticos: asma cumulativa: 14,3%; diagnóstico médico de asma: 12,9%; asma atual: 4,7%; e sintomas atuais ou reversibilidade (obstrução com resposta ao broncodilatador ou broncoprovocação positiva): 9,3%. Gravidade da asma foi avaliada conforme história de hospitalização por asma, mais de seis visitas ao pronto-socorro por ano e internação em Unidade de Tratamento Intensivo. Cerca de 30% dos asmáticos preencheram algum critério de gravidade para asma. Apenas 20% dos pacientes com asma haviam consultado no último ano pela doença e somente 30% utilizava alguma medicação antiasmática. Em relação aos fatores de risco, na análise bruta, as variáveis associadas à prevalência de “sintomas atuais de asma” foram: sexo feminino, faixa etária dos 60 aos 69 anos, cor da pele não branca, baixas escolaridade e renda familiar, história familiar de asma e atopia, história pessoal de atopia, tabagismo, índice de massa corporal baixo e a presença de distúrbios psiquiátricos menores. Na análise multivariada, construiu-se um modelo teórico-hierarquizado cujas variáveis de um determinado nível foram controladas pelas variáveis de níveis precedentes e do mesmo nível. Permaneceram relacionados à presença de “sintomas atuais de asma” os seguintes fatores de risco, em ordem decrescente de razão de prevalência: história paterna e materna de asma (RP=5,4), presença de distúrbios psiquiátricos menores (RP=2,8); idade de 60 a 69 anos (RP=2,1); renda familiar inferior a 1,01 SM (RP=2,1); história pessoal de atopia (RP=1,9); e sexo feminino (RP=1,4). Os resultados do presente estudo salientam a variação na prevalência de asma com a utilização de diferentes critérios diagnósticos, e confirmam a importância dos fatores genéticos, sociais e relacionados ao estilo de vida na ocorrência da doença.

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A reação da autoridade bancária frente a uma crise é de fundamental importância para a sua contenção. No Brasil, durante a crise do subprime, em 2008, observou-se a ocorrência de uma crise de liquidez em alguns bancos que levou o Banco Central a autorizar uma linha especial de captação de depósitos com limite muito superior ao habitual, denominado Depósito a Prazo com Garantia Especial (DPGE). Estes fatos propiciaram uma oportunidade de observar a reação dos depositantes frente a um choque exógeno ao sistema financeiro nacional para, em seguida, explorar a captação exógena de recursos devido à ampliação nos limites dos depósitos assegurados, com cobertura do Fundo Garantidor de Crédito (FGC). Além disso, analisou-se o efeito do DPGE sobre o crédito, considerando que depósitos assegurados e não-assegurados não são substitutos perfeitos e um aumento na oferta de depósitos assegurados deveria aumentar a oferta de crédito do mercado, como um todo. A estratégia empírica utilizada permitiu reconhecer os bancos emissores de DPGE, separando-os por outros fatores relacionados aos fundamentos bancários (tamanho, liquidez, qualidade dos ativos e retorno) e analisar os efeitos do DPGE nas taxas de juros praticadas na captação de depósitos a prazo, em geral. A base de dados utilizada também permitiu observar o comportamento desses bancos e a estratégia por eles utilizada na origem e destinação de tais recursos. Tomados em conjunto, os resultados encontrados são consistentes com a ideia de que depositantes migram seus recursos para a segurança durante a crise, na chamada “fuga para a qualidade” e retornam quando lhes dão a garantia necessária. Também é coerente com a teoria que diz que a substituição imperfeita entre depósitos assegurados e depósitos não-assegurados afeta a restrição de financiamentos dos bancos. O resultado deste estudo revela a importância da atuação da autoridade reguladora frente a situações críticas, bem como os efeitos no mercado causados pela permanência de um produto desenhado para uma situação específica.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objective. Evaluation of long-standing sleep bruxism (SB) patients. Study Design. Descriptive study. Results. One hundred subjects with SB (80 women and 20 men, mean age: 36.1±11.3 years) were evaluated according to the RDC/TMD and a pain questionnaire (EDOF-HC). The patients were divided into 2 groups: Group A-without (30.0%) and Group B-with orofacial pain (70.0%). AM stiffness: 36.4% in Group A and 88.6% in Group B; mean pain duration: 6.92 years; mean intensity of pain: 4.33 (VAS); quality of pain: tightness/pressure (84,3%); 95.7% of Group B had myofascial pain. Depression and somatization levels were different between the groups (p = 0.001). Higher frequency of depression was found with body pain or presence of comorbidities. Conclusion. The data presented in this study showed statistical differences between long-standing bruxism without and with chronic facial pain; the two questionnaires allowed interaction between the chief complaint and the clinical findings; depression levels increased with pain in several regions of the body. © 2006 Elsevier Inc. All rights reserved.

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We show that self-localized ground states can be created in the spin-balanced gas of fermions with repulsion between the spin components, whose strength grows from the center to periphery, in combination with the harmonic-oscillator (HO) trapping potential acting in one or two transverse directions. We also consider the ground state in the noninteracting Fermi gas under the action of the spatially growing tightness of the one- or two-dimensional (1D or 2D) HO confinement. These settings are considered in the framework of the Thomas-Fermi-von Weizsäcker (TF-vW) density functional. It is found that the vW correction to the simple TF approximation (the gradient term) is nearly negligible in all situations. The properties of the ground state under the action of the 2D and 1D HO confinement with the tightness growing in the transverse directions are investigated too for the Bose-Einstein condensate with the self-repulsive nonlinearity. © 2013 American Physical Society.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)