50,074 research outputs found

    Survey of roughness by stochastic oscillations

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    In this paper, connections between surface roughness and directed polymers in random medium are studied, when the surface is considered as a directed line undergoing stochastic oscillations. This is performed by studying the influence of a stochastic elastic forcing term κy+η(s)-\kappa y+\eta(s), on a particle moving along a rough surface. Two models are proposed and analysed in this way: the random-walk process (RW) in its discrete and continuous form, and a Markovian process via the Ornstein-Uhlenbeck (O-U) process. It is shown that the continuous RW leads to an oscillator equation, via an effective action obeying a KPZ equation which is solved analytically. The O-U process allows to obtain information on the profile of surface for a long size substrate. The analogy with the roughness is achieved by introducing a quantity suited to directed line formalism: the height velocity variation h/s\partial h/\partial s.Comment: 8 pages, 4 figure

    Clarifying the Concept of Salvation: A Philosophical Approach to the Power of Faith in Christ's Resurrection

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    In this paper, I develop a philosophical clarification of the statement "faith in the resurrection of Christ saves men from sin", using some of the main arguments and hypotheses of my recent book, ’The Ways of Salvation (Les Voies du salut’, Paris 2010). I begin with some remarks on the theme of salvation in contemporary language and philosophy. I then sketch a conceptual analysis of the concept of salvation, first in its general sense, then in its specifically Christian one. Finally, I offer a hypothesis on the ’modus operandi’ of salvation, or at least of one aspect of salvation as understood by Christianit

    Regulatory versus Informational Value of Bond Ratings: Hints from History ...

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    A multivariate analysis can be used in order to investigate the relationship between bond yields, ratings and standard control variables. Replicating such a test on a number of cross-sections may evidence a possible impact of financial regulations relying on ratings. Datasets for American corporate bond issues allow a focus on two key events of the development of rating driven regulations: the valuation of bank and life insurance portfolios introduced in the 1930’s and the net capital requirements for broker dealers introduced in the 1970’s. The “value” of bond ratings does show some improvement once these regulations have been passed.Bond ratings, bond yields, financial regulation.