4,823 research outputs found

    An explicit KO-degree map and applications

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    The goal of this note is to study the analog in unstable A1{{\mathbb A}^1}-homotopy theory of the unit map from the motivic sphere spectrum to the Hermitian K-theory spectrum, i.e., the degree map in Hermitian K-theory. We show that "Suslin matrices", which are explicit maps from odd dimensional split smooth affine quadrics to geometric models of the spaces appearing in Bott periodicity in Hermitian K-theory, stabilize in a suitable sense to the unit map. As applications, we deduce that KiMW(F)=GWii(F)K^{MW}_i(F) = GW^i_i(F) for i3i \leq 3, which can be thought of as an extension of Matsumoto's celebrated theorem describing K2K_2 of a field. These results provide the first step in a program aimed at computing the sheaf πnA1(An0)\pi_{n}^{{\mathbb A}^1}({\mathbb A}^n \setminus 0) for n4n \geq 4.Comment: 36 Pages, Final version, to appear Journal of Topolog

    Generalized Robba rings

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    We prove that any projective coadmissible module over the locally analytic distribution algebra of a compact pp-adic Lie group is finitely generated. In particular, the category of coadmissible modules does not have enough projectives. In the Appendix a "generalized Robba ring" for uniform pro-pp groups is constructed which naturally contains the locally analytic distribution algebra as a subring. The construction uses the theory of generalized microlocalization of quasi-abelian normed algebras that is also developed there. We equip this generalized Robba ring with a self-dual locally convex topology extending the topology on the distribution algebra. This is used to show some results on coadmissible modules.Comment: with an appendix by Peter Schneider; revised; new titl

    Applications of aerospace technology in biology and medicine

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    Utilization of National Aeronautics and Space Administration (NASA) technology in medicine is discussed. The objective is best obtained by stimulation of the introduction of new or improved commercially available medical products incorporating aerospace technology. A bipolar donor/recipient model of medical technology transfer is presented to provide a basis for the team's methodology. That methodology is designed to: (1) identify medical problems and NASA technology that, in combination, constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial transfers were completed: the Stowaway, a lightweight wheelchair that provides mobility for the disabled and elderly in the cabin of commercial aircraft, and Micromed, a portable medication infusion pump for the reliable, continuous infusion of medications such as heparin or insulin. The marketing and manufacturing factors critical to the commercialization of the lightweight walker incorporating composite materials were studied. Progress was made in the development and commercialization of each of the 18 currently active projects

    Scrum for product innovation : a longitudinal embedded case study

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    This article describes the innovation processes used in a partnership between Add Latent Ltd., an asset integrity and maintenance management consulting services provider in the energy sector and University of Salford. The challenge faced by the company is to make their in-house expertise more readily available to a worldwide audience. A longitudinal embedded case study has been used to investigate how installable desktop software applications have been redesigned to create a new set of cloud hosted software services. The innovation team adapted an agile scrum process to include exploratory prototyping and manage the geographical distribution of the team members. A minimum viable product was developed that integrated functional elements of previous software tools into an end-to-end data collection, analysis and visualisation product called AimHi which uses a cloud-hosted web services approach. Field trials were conducted using the software at the Uniper, Isle of Grain power station in Kent, UK. Enhancements were made to the AimHi product which was adopted for use at the Uniper site. The product emerged from a Knwledge Transfer Partnership whci was evaluated on cmplettion by InnovateUK and awarded the highest possible “outstanding” grade. The article illustrates how the scrum software development method was tailored for a product innovation context. Extended periods of evaluation and reflection, prototyping and requirement refinement were combined with periods of incremental feature development using sprints. The AimHi product emerged from a technology transfer and innovation project that has successfully reconciled conflicting demands from customers, universities, partner companies and project staff members

    Discrete Model of Ideological Struggle Accounting for Migration

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    A discrete in time model of ideological competition is formulated taking into account population migration. The model is based on interactions between global populations of non-believers and followers of different ideologies. The complex dynamics of the attracting manifolds is investigated. Conversion from one ideology to another by means of (i) mass media influence and (ii) interpersonal relations is considered. Moreover a different birth rate is assumed for different ideologies, the rate being assumed to be positive for the reference population, made of initially non-believers. Ideological competition can happen in one or several regions in space. In the latter case, migration of non-believers and adepts is allowed; this leads to an enrichment of the ideological dynamics. Finally, the current ideological situation in the Arab countries and China is commented upon from the point of view of the presently developed mathematical model. The massive forced conversion by Ottoman Turks in the Balkans is briefly discussed.Comment: 24 pages, with 5 figures and 52 refs.; prepared for a Special issue of Advances in Complex System

    Formal groups arising from formal punctured ribbons

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    We investigate Picard functor of a formal punctured ribbon. We prove that under some conditions this functor is representable by a formal group scheme. Formal punctured ribbons were introduced in arXiv:0708.0985.Comment: 42 pages, minor change

    Specific Resistance of Pd/Ir Interfaces

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    From measurements of the current-perpendicular-to-plane (CPP) total specific resistance (AR = area times resistance) of sputtered Pd/Ir multilayers, we derive the interface specific resistance, 2AR(Pd/Ir) = 1.02 +/- 0.06 fOhmm^2, for this metal pair with closely similar lattice parameters. Assuming a single fcc crystal structure with the average lattice parameter, no-free-parameter calculations, including only spd orbitals, give for perfect interfaces, 2AR(Pd/Ir)(Perf) = 1.21 +/-0.1 fOhmm^2, and for interfaces composed of two monolayers of a random 50%-50% alloy, 2AR(Pd/Ir)(50/50) = 1.22 +/- 0.1 fOhmm^2. Within mutual uncertainties, these values fall just outside the range of the experimental value. Updating to add f-orbitals gives 2AR(Pd/Ir)(Perf) = 1.10 +/- 0.1 fOhmm^2 and 2AR(Pd/Ir)(50-50) = 1.13 +/- 0.1 fOhmm^2, values now compatible with the experimental one. We also update, with f-orbitals, calculations for other pairsComment: 3 pages, 1 figure, in press in Applied Physics Letter

    Local Thermal and Chemical Equilibration and the Equation of State in Relativistic Heavy Ion Collisions

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    Thermodynamical variables and their time evolution are studied for central relativistic heavy ion collisions from 10.7 to 160 AGeV in the microscopic Ultrarelativistic Quantum Molecular Dynamics model (UrQMD). The UrQMD model exhibits drastic deviations from equilibrium during the early high density phase of the collision. Local thermal and chemical equilibration of the hadronic matter seems to be established only at later stages of the quasi- isentropic expansion in the central reaction cell with volume 125 fm3^{3}. distributions at all collision energies for t10fm/ct\geq 10 fm/c with a unique Baryon energy spectra in this cell are approximately reproduced by Boltzmann rapidly dropping temperature. At these times the equation of state has a simple form: P(0.120.15)ϵP \cong (0.12-0.15) \epsilon. At 160 AGeV the strong deviation from chemical equilibrium is found for mesons, especially for pions, even at the late stage of the reaction. The final enhancement of pions is supported by experimental data.Comment: 17 Pages, LaTex, 8 eps figures. Talk given at SQM'98 conference, 20-24 July 1998, Padova, Italy, submitted to J. Phys.

    Geometry-induced asymmetric diffusion

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    Past work has shown that ions can pass through a membrane more readily in one direction than the other. We demonstrate here in a model and an experiment that for a mixture of small and large particles such asymmetric diffusion can arise solely from an asymmetry in the geometry of the pores of the membrane. Our deterministic simulation considers a two-dimensional gas of elastic disks of two sizes diffusing through a membrane, and our laboratory experiment examines the diffusion of glass beads of two sizes through a metal membrane. In both experiment and simulation, the membrane is permeable only to the smaller particles, and the asymmetric pores lead to an asymmetry in the diffusion rates of these particles. The presence of even a small percentage of large particles can clog a membrane, preventing passage of the small particles in one direction while permitting free flow of the small particles in the other direction. The purely geometric kinetic constraints may play a role in common biological contexts such as membrane ion channels.Comment: published with minuscule change
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