1,864 research outputs found

    Biliteral Crossword

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    A crossword puzzle

    Approximation in FEM, DG and IGA: a theoretical comparison

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    In this paper we compare the approximation properties of degree p spline spaces with different numbers of continuous derivatives. We prove that, for a given space dimension, Cp-1 splines provide better a priori error bounds for the approximation of functions in Hp+1(0 , 1). Our result holds for all practically interesting cases when comparing Cp-1 splines with C- 1 (discontinuous) splines. When comparing Cp-1 splines with C splines our proof covers almost all cases for p≥ 3 , but we can not conclude anything for p= 2. The results are generalized to the approximation of functions in Hq+1(0 , 1) for q< p, to broken Sobolev spaces and to tensor product spaces

    Positive solutions to find a job: cultural mismatches between companies and employees

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    A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and EconomicsPsychology is not just the study of disease, weakness, and damage; it also is the study of strength and virtue (Seligman & Csikszentmihalyi, 2000). Attempts to change this thinking school is the theory of Positive Psychology from Seligman which is the base for this dissertation. The methodology used in our model followed the hypothesis testing in order to assess the veracity of positive behaviors affecting the outcome of finding a job. Therefore, through the use of Logistic Regressions, several results proved that positive behaviors such as optimism are indeed affecting the way we apply to a job and how satisfied we are with it. Thus, since each country presents a different set of cultural behaviors such as the level of optimism and self-determination, companies and education systems that are internationalizing should concern cultural impacts and maybe mind about cultural teachings to local workers to improve their adaptation to the institution. The models studied in this dissertation should be tested again with different samples in order to bring more consistency to this subject

    Sulphur-bearing molecules in AGB stars I: The occurrence of hydrogen sulfide

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    Through a survey of (sub-)millimetre emission lines of various sulphur-bearing molecules, we aim to determine which molecules are the primary carriers of sulphur in different types of AGB stars. In this paper, the first in a series, we investigate the occurrence of H2_2S in AGB circumstellar envelopes and determine its abundance, where possible. We have surveyed 20 AGB stars with a range of mass-loss rates and of different chemical types using the APEX telescope to search for rotational transition lines of five key sulphur-bearing molecules: CS, SiS, SO, SO2_2 and H2_2S. Here we present our results for H2_2S, including detections, non-detections and detailed radiative transfer modelling of the detected lines. We compare results based on different descriptions of the molecular excitation of H2_2S and different abundance distributions, including those derived from chemical modelling results. We detected H2_2S towards five AGB stars, all of which have high mass-loss rates of M˙5×106M\dot{M}\geq 5\times 10^{-6}M_\odot yr1^{-1} and are oxygen-rich. H2_2S was not detected towards the carbon or S-type stars that fall in a similar mass-loss range. For the stars in our sample with detections, we find peak o-H2_2S abundances relative to H2_2 between 4×1074\times 10^{-7} and 2.5×1052.5\times 10^{-5}. Overall, we conclude that H2_2S can play a significant role in oxygen-rich AGB stars with higher mass-loss rates, but is unlikely to play a key role in stars of other chemical types or the lower mass-loss rate oxygen-rich stars. For two sources, V1300 Aql and GX Mon, H2_2S is most likely the dominant sulphur-bearing molecule in the circumstellar envelope.Comment: 14 pages, 7 figures, accepted in A&

    EMIR anti-procyclicality margin measures for central counterparties

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    Central Counterparties - CCP’s - have been at the the heart of Financial system for several years. The CCP’s are part of the Market Infrastructure system. Their core role is to ensure that counterparties can exchange cash and securities. ”These market infrastructures are sets of rules, processes and operational arrangements managing, reducing and allocating the inherent risks arising from transactions between market participants.” [3] The focus of the Central Counterparties, also known as CCP’s is to maintain market efficiency and credibility. The Central Counterparties are composed by a group of Clearing Members. These Clearing Members then have their own clients to intermediate the transactions with. CCP’s distinguish them by different account type (House account and Client account). Not only the accounts are different but so are the responsibilities. The CCP only faces its Clearing Members risk and not their Clearing Members clients, hence a contract is only established with the Clearing Member. Central Counterparties have a set of rules that must be followed by every participants. There are minimum cash deposits, Initial Margins, Variation Margins, Additional Margins and Default Fund contributions. These contributions are layers of cash in order to protect the Central Counterparty system. This means that all parties have a skin-in-the-game, a share at stake. This is the best incentive for all participants to play by the rules. In order for Central Counterparties to be protected from possible defaults the above contributions are requested. These contributions are established by a ”Rule book”, Margin Methodology documents, Principles for Financial Market Infrastructure Disclosure (PFMI) and at least a quarterly Quantitative Disclosure is required by European Securities and Markets Authority (ESMA). The contributions follow specific margin methodologies and parameters. The margin methodologies used by different CCP’s might differ according to the type of products and the CCP’s sophistication and willingness to invest in risk management. Aiming to achieve some standardisation within the Clearing Counterparties, there is a minimum Value-at-Risk for each product determined by ESMA. In addition, guidelines on anti-procyclicality measures are defined. The purpose of this dissertation is to assess the importance of different margin methodologies used by Clearing Counterparties concerning anti-procyclicality measures and their effectiveness.Contrapartes Centrais - CCP’s- têm estado no centro do Sistema Financeiro há vários anos. As Contrapartes Centrais são parte do Sistema de Infraestrutura dos Mercados Financeiros. O seu papel principal é garantir que contrapartes possam trocar dinheiro e títulos financeiros. ”Estes Sistemas de Infraestrutura de Mercados Financeiros são um conjunto de regras, processos e organização operacional, reduzindo e alocando os riscos inerentes às transações financeiras entre participantes do mercado.” [3] O principal objetivo das Contrapartes Centrais, também chamado CCP’s, é manter a eficiência e credibilidade do mercado. As Contrapartes Centrais são compostas por um conjunto de Membros. Estes Membros têm os seus clientes com quem há intermediação de transações. As CCP’s distinguem-nas por diferentes tipos de contas (contas de Casa ou Cliente). Não só as contas são diferentes, mas também as suas responsabilidades. As CCP’s enfrentam o risco dos Membros, mas não dos seus clientes, portanto, os contratos são definidos entre Membros e a Contraparte Central. As Contrapartes Centrais regem-se por um conjunto de regras, que todos os participantes devem cumprir. Há depósitos de dinheiro mínimos, Margens Iniciais, Margens Variáveis, Margens adicionais e contribuições para o fundo de incumprimento. Estas contribuições feitas em dinheiro protegem a da Contraparte Central. Este esquema implica que todas as partes têm uma parcela dos seus ativos em risco. Este é o melhor incentivo para que todos os participantes cumpram as regras estabelecidas. Para que as Contrapartes Centrais estejam protegidas de possíveis falências as contribuições acimas mencionadas são requeridas. Estas contribuições são estabelecidas num ”Rule Book”, documentos relativos à metodologia de margens, “Principles for Financial Market Infrastructure Disclosure” (PFMI) e por fim ”Quantitative Disclosure” é requerido pelo European Securities and Markets Authority” (ESMA). As contribuições seguem certas metodologias e parâmetros. As metodologias das margens utilizadas por diferentes Contrapartes Centrais podem ser diferentes consoante o tipo de produtos e a sofisticação e pré-disposição para investir em gestão de risco. Para que haja alguma estandardização das Contrapartes Centrais, há valores mínimos de Value-at-Risk para cada produto determinados pela ESMA. Adicionalmente, diretrizes de anti-prociclicalidade estão definidas. O objetivo desta dissertação ´e analisar a importância de diferentes metodologias de margens usadas pelas Contrapartes Centrais e verificar a sua eficácia para evitar prociclicalidad

    Fado as an added value for tourism in Lisbon

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    This work-project is about the impact of Fado in the development of the tourism in Portugal and, more specifically, in Lisbon. It makes sense because it is thought that Fado is not being explored the way it should to have the best contribution possible for tourism. For the development of this work we first wrote about Fado’s history, cultural tourism and then interviewed several tourists that were attending Fado performances. These interviews made us conclude tourists appreciated a lot their visit to “Casas de Fado” and that Fado is an important asset for Portuguese tourism development. Because of this conclusion, some suggestions are made to better promote Fado in Portugal and worldwide

    Coexistence of Paramagnetic-Charge-Ordered and Ferromagnetic-Metallic Phases in La0.5Ca0.5MnO3 evidenced by ESR

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    Throughout a complete Electron Spin Resonance (ESR) and magnetization study of La0.5Ca0.5MnO3, we discuss about the nature of the complex phase-segregated state established in this compound below T~210 K. Between TN<T<TC, the ESR spectra shows two lines characteristic of two different magnetic phases. From the resonance field (Hr) derived for each line we argue that the incommensurate-charge-ordering phase (ICO) which coexists with ferromagnetic-metallic (FMM) clusters in this temperature interval, is mainly paramagnetic and not antiferromagnetic. The FMM/ICO ratio can be tuned with a relatively small field, which suggests that the internal energy associated with those phases is very similar. Below TN, there is an appreciable FM contribution to the magnetization and the ESR spectra indicates the presence of FM clusters in an antiferromagnetic matrix (canted). Our results show that ESR could be a very useful tool to investigate the nature of the phase-separated state now believed to play a fundamental role in the physics of mixed valent manganites.Comment: 6 pages, 6 figure

    Mapping monthly rainfall data in Galicia (NW Spain) using inverse distances and geostatistical methods

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    In this paper, results from three different interpolation techniques based on Geostatistics (ordinary kriging, kriging with external drift and conditional simulation) and one deterministic method (inverse distances) for mapping total monthly rainfall are compared. The study data set comprised total monthly rainfall from 1998 till 2001 corresponding to a maximum of 121 meteorological stations irregularly distributed in the region of Galicia (NW Spain). Furthermore, a raster Geographic Information System (GIS) was used for spatial interpolation with a 500&times;500 m grid digital elevation model. Inverse distance technique was appropriate for a rapid estimation of the rainfall at the studied scale. In order to apply geostatistical interpolation techniques, a spatial dependence analysis was performed; rainfall spatial dependence was observed in 33 out of 48 months analysed, the rest of the rainfall data sets presented a random behaviour. Different values of the semivariogram parameters caused the smoothing in the maps obtained by ordinary kriging. Kriging with external drift results were according to former studies which showed the influence of topography. Conditional simulation is considered to give more realistic results; however, this consideration must be confirmed with new data
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