9,592 research outputs found

    Real options with priced regime-switching risk

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    We develop a model of regime-switching risk premia as well as regimedependent factor risk premia to price real options. The model incorporates the observation that the underlying risky income streams of real options are subject to discrete shifts over time as well as random changes. The presence of discrete shifts is due to systematic and unsystematic risk associated with changes in business cycles or in economic policy regimes or events such as takeovers, major changes in business plans. We analyze the impact of regime switching behavior on the valuation of projects and investment opportunities. We find that accounting for Markov switching risk results in a delay in the expected timing of the investment while the regime-specific factor risk premia make the possibility of a regime shift more pronounced

    The effects of different parameterizations of Markov-switching in a CIR model of bond pricing

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    We examine several discrete-time versions of the Cox, Ingersoll and Ross (CIR) model for the term structure, in which the short rate is subject to discrete shifts. Our empirical analysis suggests that careful consideration of which parameters of the short-term interest rate equation that are allowed to be switched is crucial. Ignoring this issue may result in a parameterization that produces no improvement (in terms of bond pricing) relative to the standard CIR model, even when there are clear breaks in the data

    Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method

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    The determination of the longitudinal spin Seebeck effect (LSSE) coefficient is currently plagued by a large uncertainty due to the poor reproducibility of the experimental conditions used in its measurement. In this work we present a detailed analysis of two different methods used for the determination of the LSSE coefficient. We have performed LSSE experiments in different laboratories, by using different setups and employing both the temperature difference method and the heat flux method. We found that the lack of reproducibility can be mainly attributed to the thermal contact resistance between the sample and the thermal baths which generate the temperature gradient. Due to the variation of the thermal resistance, we found that the scaling of the LSSE voltage to the heat flux through the sample rather than to the temperature difference across the sample greatly reduces the uncertainty. The characteristics of a single YIG/Pt LSSE device obtained with two different setups was (1.143±0.007)⋅10−7(1.143\pm0.007)\cdot 10^{-7} Vm/W and (1.101±0.015)⋅10−7(1.101\pm0.015)\cdot 10^{-7} Vm/W with the heat flux method and (2.313±0.017)⋅10−7(2.313\pm0.017)\cdot 10^{-7} V/K and (4.956±0.005)⋅10−7(4.956\pm0.005)\cdot 10^{-7} V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.Comment: PDFLaTeX, 10 pages, 6 figure

    Latinos Move the US Economy, But Hardly Get to Write About it

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    Cuando se escribe sobre la economĂ­a, hay que incluir una diversidad de voces en la historia porque todo el mundo participa en la economĂ­a de una forma u otra. La misma filosofĂ­a debe aplicarse a quien escribe estas historias. Sin embargo, dentro de todas las complicaciones que existen dentro de la industria de las comunicaciones, hay un problema en particular desatendido. El campo de estudios econĂłmicos tiene fama de carecer de expertos de diversa procedencia, y parece repetirse en la industria del periodismo. Antes de este proyecto, solo se me occurĂ­a un puñado de periodistas latinos especializados en el area de economĂ­a y finanzas. ÂżPor quĂ©? ÂżPor quĂ© no hay mĂĄs? El Reynolds Center publicĂł a principios de este año la Encuesta Salarial del Periodismo de Negocios, y el origen racial de los encuestados plantea dudas: 80,8% blancos, 4,7% negros, 5,5% asiĂĄticos o de las islas del PacĂ­fico y 4,7% multirraciales. Mientras tanto, para el New York Times, segĂșn un informe realizado por miembros del Gremio, tienes un 61% menos de probabilidad de recibir una puntuaciĂłn alta en las evaluaciones anuales de rendimiento si te identificas como latino. ÂżQuĂ© estĂĄ fallando a los reporteros latinos en el sistema? DespuĂ©s de entrevistar a cinco periodistas latinos y consultar con fuentes expertas, pude aclarar que la poca cantidad de latinos cubriendo la economĂ­a se debe a una combinaciĂłn de factores, como la falta de acceso a la educaciĂłn en el campo, la pobre retenciĂłn de talento y discrimen en espacios de trabajo. Los medios de comunicaciĂłn no sĂłlo deberĂ­an concentrarse en diversificar sus salas de redacciones, sino tambiĂ©n diversificar sus nichos. Periodistas latinos pueden traer ideas e identificar matices para que una historia sea redonda, inclusiva y completa. Y de eso se trata el periodismo: honrar las realidades de los ciudadanos de un paĂ­s y fiscalizar a aquellos con poder para mejorar la calidad de vida de todos

    UV (IUE) spectra of the central stars of high latitude planetary nebulae Hb7 and Sp3

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    We present an analysis of the UV (IUE) spectra of the central stars of Hb7 and Sp3. Comparison with the IUE spectrum of the standard star HD 93205 leads to a spectral classification of O3V for these stars, with an effective temperature of 50,000 K. From the P-Cygni profiles of CIV (1550 A), we derive stellar wind velocities and mass loss rates of -1317 km/s +/- 300 km/s and 2.9X10^{-8} solar mass yr^{-1} and -1603 km/s +/- 400 km/s and 7X10^{-9} solar mass yr^{-1} for Hb7 and Sp3 respectively. From all the available data, we reconstruct the spectral energy distribution of Hb7 and Sp3.Comment: 4 pages, 3 figures, latex, accepted for publication in Astronomy & Astrophysic

    Quantum computations with atoms in optical lattices: marker qubits and molecular interactions

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    We develop a scheme for quantum computation with neutral atoms, based on the concept of "marker" atoms, i.e., auxiliary atoms that can be efficiently transported in state-independent periodic external traps to operate quantum gates between physically distant qubits. This allows for relaxing a number of experimental constraints for quantum computation with neutral atoms in microscopic potential, including single-atom laser addressability. We discuss the advantages of this approach in a concrete physical scenario involving molecular interactions.Comment: 15 pages, 14 figure

    Patterns of food avoidance in chronic fatigue syndrome: is there a case for dietary recommendations?

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    OBJECTIVES: To assess the dietary habits and food avoidance-behavior in patients with Chronic Fatigue Syndrome (CFS). METHODS: Cross-sectional pilot study with 28 patients diagnosed with severe CFS. Eating habits were assessed with a food frequency questionnaire and 3-day food records. We analyzed variables related to dietary restrictions induced by symptoms or external information. RESULTS: The most prevalent restrictions were for dairy products and gluten-containing grains, with 22 and 15 restricting patients, respectively. Patients reported different digestive symptoms, which did not improve with the use of exclusion diets. Thirteen patients had received information against the intake of certain foods through different sources. Six cases of grains restriction and 11 of dairy were compatible with a counseling-induced pattern of exclusion. CONCLUSIONS: There is not a homogeneous pattern of food avoidance. Dietary restrictions should be based on a proven food allergy or intolerance. Dietary counseling should be based on sound nutritional knowledge

    The Running of the Cosmological and the Newton Constant controlled by the Cosmological Event Horizon

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    We study the renormalisation group running of the cosmological and the Newton constant, where the renormalisation scale is given by the inverse of the radius of the cosmological event horizon. In this framework, we discuss the future evolution of the universe, where we find stable de Sitter solutions, but also "big crunch"-like and "big rip"-like events, depending on the choice of the parameters in the model.Comment: 14 pages, 7 figures, minor improvements, references adde
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