18,204 research outputs found

    Exploring Energy-Efficient Reconfigurable Architectures for DSP Algorithms

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    Future hand-held multimedia terminals require a very high performance on a very small energy budged. Such devices can only be realized if their entire system is energy cognisant. In this paper a reconfigurable systems-architecture for mobile multimedia systems is introduced. The Field Programmable Function Array (FPFA) is discussed in detail. Several digital signal processing algorithms are discussed and mapped on the FPFA. Also,the power radius theory about low-power design is introduced

    A Reconfigurable Platform For Cognitive Radio

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    TodayÂżs rigid spectrum allocation scheme creates a spectrum scarcity problem for future wireless communications. Measurements show that a wide range of the allocated frequency bands are rarely used. Cognitive radio is a novel approach to improve the spectrum usage, which is able to sense the spectrum and adapt its transmission while coexisting with the licensed spectrum user. A reconfigurable radio platform is required to provide enough adaptivity for cognitive radio. In this paper, we propose a cognitive radio system architecture and discuss its possible implementation on a heterogeneous reconfigurable radio platform

    Thermalisation of inhomogeneous quantum scalar fields in 1+1D

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    Using an improved version of the Hartree approximation, allowing for ensembles of inhomogeneous configurations, we show in a λϕ4\lambda \phi^4 theory, that initially the system thermalises with a Bose-Einstein distribution. For later times and larger couplings we see deviations.Comment: Presented at CAPP 2000, 4 pages including figures, typo's correcte

    Deformation rings which are not local complete intersections

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    We study the inverse problem for the versal deformation rings R(Γ,V)R(\Gamma,V) of finite dimensional representations VV of a finite group Γ\Gamma over a field kk of positive characteristic pp. This problem is to determine which complete local commutative Noetherian rings with residue field kk can arise up to isomorphism as such R(Γ,V)R(\Gamma,V). We show that for all integers n≄1n \ge 1 and all complete local commutative Noetherian rings W\mathcal{W} with residue field kk, the ring W[[t]]/(pnt,t2)\mathcal{W}[[t]]/(p^n t,t^2) arises in this way. This ring is not a local complete intersection if pnW≠{0}p^n\mathcal{W}\neq\{0\}, so we obtain an answer to a question of M. Flach in all characteristics.Comment: 16 page

    The Chameleon project in retrospective

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    In this paper we describe in retrospective the main results of a four year project, called Chameleon. As part of this project we developed a coarse-grained reconfigurable core for DSP algorithms in wireless devices denoted MONTIUM. After presenting the main achievements within this project we present the lessons learned from this project

    Modelling of a reverse flow catalytic membrane reactor for the partial oxidation of methane

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    Gas-To-Liquid (GTL) processes have great potential as alternative to conventional oil and coal processing for the production of liquid fuels. In GTL-processes the partial oxidation of methane (POM) is combined with the Fischer-Tropsch reaction. An important part of the investment costs of a conventional GTL-plant is related to cryogenic air separation. These costs could be substantially reduced by separating air with recently developed oxygen perm-selective perovskite membranes, which operate at similar temperatures as a POM reactor. Integration of these membranes in the POM reactor seems very attractive because oxygen reacts at the membrane surface resulting in a high driving force over the membrane increasing the oxygen permeation
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