3,659 research outputs found

    Global carbon mechanisms: emerging lessons and implications

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    The global carbon mechanisms have succeeded in channelling billions of Euros towards low-carbon investments in developing countries, but cannot deliver what is needed in the future without support including reforms and involvement of North America. The publication shows that the Clean Development Mechanism itself has triggered more than 4000 emission-reducing projects in developing countries and is likely to save up to 2 billion tonnes of emissions reductions by 2012. Other Mechanisms under the Kyoto Protocol, including emerging Green Investment Schemes, show great promise. But many of the gains are at peril, warns the publication, unless governments act to restore balance in the markets and learn the emerging lessons. The publication identifies and analyses three fundamental problems that must be tackled. An excess of supply over demand will mean low prices in the market without government action There must be reforms to improve the efficiency and environmental performance of the existing mechanisms The Global Carbon Mechanisms are and will continue to be a central pillar in the global response to climate change to 2020, but are not on their own sufficient. They need to be complemented by other action to support the required cuts in carbon emission

    Energy Efficient Service Delivery in Clouds in Compliance with the Kyoto Protocol

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    Cloud computing is revolutionizing the ICT landscape by providing scalable and efficient computing resources on demand. The ICT industry - especially data centers, are responsible for considerable amounts of CO2 emissions and will very soon be faced with legislative restrictions, such as the Kyoto protocol, defining caps at different organizational levels (country, industry branch etc.) A lot has been done around energy efficient data centers, yet there is very little work done in defining flexible models considering CO2. In this paper we present a first attempt of modeling data centers in compliance with the Kyoto protocol. We discuss a novel approach for trading credits for emission reductions across data centers to comply with their constraints. CO2 caps can be integrated with Service Level Agreements and juxtaposed to other computing commodities (e.g. computational power, storage), setting a foundation for implementing next-generation schedulers and pricing models that support Kyoto-compliant CO2 trading schemes

    Fractional-order operators: Boundary problems, heat equations

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    The first half of this work gives a survey of the fractional Laplacian (and related operators), its restricted Dirichlet realization on a bounded domain, and its nonhomogeneous local boundary conditions, as treated by pseudodifferential methods. The second half takes up the associated heat equation with homogeneous Dirichlet condition. Here we recall recently shown sharp results on interior regularity and on LpL_p-estimates up to the boundary, as well as recent H\"older estimates. This is supplied with new higher regularity estimates in L2L_2-spaces using a technique of Lions and Magenes, and higher LpL_p-regularity estimates (with arbitrarily high H\"older estimates in the time-parameter) based on a general result of Amann. Moreover, it is shown that an improvement to spatial CC^\infty -regularity at the boundary is not in general possible.Comment: 29 pages, updated version, to appear in a Springer Proceedings in Mathematics and Statistics: "New Perspectives in Mathematical Analysis - Plenary Lectures, ISAAC 2017, Vaxjo Sweden

    Smeared heat-kernel coefficients on the ball and generalized cone

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    We consider smeared zeta functions and heat-kernel coefficients on the bounded, generalized cone in arbitrary dimensions. The specific case of a ball is analysed in detail and used to restrict the form of the heat-kernel coefficients AnA_n on smooth manifolds with boundary. Supplemented by conformal transformation techniques, it is used to provide an effective scheme for the calculation of the AnA_n. As an application, the complete A5/2A_{5/2} coefficient is given.Comment: 23 pages, JyTe

    The hybrid spectral problem and Robin boundary conditions

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    The hybrid spectral problem where the field satisfies Dirichlet conditions (D) on part of the boundary of the relevant domain and Neumann (N) on the remainder is discussed in simple terms. A conjecture for the C_1 coefficient is presented and the conformal determinant on a 2-disc, where the D and N regions are semi-circles, is derived. Comments on higher coefficients are made. A hemisphere hybrid problem is introduced that involves Robin boundary conditions and leads to logarithmic terms in the heat--kernel expansion which are evaluated explicitly.Comment: 24 pages. Typos and a few factors corrected. Minor comments added. Substantial Robin additions. Substantial revisio

    C*-Structure and K-Theory of Boutet de Monvel's Algebra

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    We consider the norm closure AA of the algebra of all operators of order and class zero in Boutet de Monvel's calculus on a manifold XX with boundary YY. We first describe the image and the kernel of the continuous extension of the boundary principal symbol to AA. If the XX is connected and YY is not empty, we then show that the K-groups of AA are topologically determined. In case the manifold, its boundary and the tangent space of the interior have torsion-free K-theory, we prove that Ki(A/K)K_i(A/K) is isomorphic to the direct sum of Ki(C(X))K_i(C(X)) and K1i(C0(TX))K_{1-i}(C_0(TX')), for i=0,1, with KK denoting the compact ideal and TXTX' the tangent bundle of the interior of XX. Using Boutet de Monvel's index theorem, we also prove this result for i=1 without assuming the torsion-free hypothesis. We also give a composition sequence for AA.Comment: Final version, to appear in J. Reine Angew. Math. Improved K-theoretic result

    Ellipticity Conditions for the Lax Operator of the KP Equations

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    The Lax pseudo-differential operator plays a key role in studying the general set of KP equations, although it is normally treated in a formal way, without worrying about a complete characterization of its mathematical properties. The aim of the present paper is therefore to investigate the ellipticity condition. For this purpose, after a careful evaluation of the kernel with the associated symbol, the majorization ensuring ellipticity is studied in detail. This leads to non-trivial restrictions on the admissible set of potentials in the Lax operator. When their time evolution is also considered, the ellipticity conditions turn out to involve derivatives of the logarithm of the tau-function.Comment: 21 pages, plain Te
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