23,308 research outputs found

    Approaching Polyglot Programming: What Can We Learn from Bilingualism Studies?

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    The Core of a coalitional exchange economy

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    In pure exchange economies, a poor attention has been given to how the individual consumption possibilities of the members of a coalition should be represented. It seems economically reasonable that our knowledge and our possibility to make decisions depend on the coalition we belong to. We define a coalitional exchange economy by considering a pure exchange economy in which the individual consumption sets of consumers within a coalition depend on the membership of the coalition. Our definition includes as a particular case the classical definition of pure exchange economy. We adapt the core concept to a coalitional exchange economy, and we show the non-emptiness of the core. Finally, we discuss more general setting where individual preferences are also depending on the coalitions.Cooperative game, core, exchange economy, consumption possibility.

    Open charm and charmonium production at RHIC

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    We calculate open charm and charmonium production in Au + Au reac- tions at ps = 200 GeV within the hadron-string dynamics (HSD) transport approach employing open charm cross sections from pN and N reactions that are fitted to results from PYTHIA and scaled in magnitude to the available experimental data. Charmonium dissociation with nucleons and formed mesons to open charm (D + ¯D pairs) is included dynamically. The comover dissociation cross sections are described by a simple phase-space model including a single free parameter, i.e. an interaction strength M2 0 , that is fitted to the J/ suppression data for Pb + Pb collisions at SPS energies. As a novel feature we implement the backward channels for char- monium reproduction by D ¯D channels employing detailed balance. From our dynamical calculations we find that the charmonium recreation is com- parable to the dissociation by comoving mesons. This leads to the final result that the total J/ suppression at ps = 200 GeV as a function of centrality is slightly less than the suppression seen at SPS energies by the NA50 Collaboration, where the comover dissociation is substantial and the backward channels play no role. Furthermore, even in case that all di- rectly produced J/ mesons dissociate immediately (or are not formed as a mesonic state), a sizeable amount of charmonia is found asymptotically due to the D + ! J/ + meson channels in central collisions of Au + Au at ps = 200 GeV which, however, is lower than the J/ yield expected from f pp collis ns

    Baryon stopping and strange baryon and anti-baryon production at ultrarelativistic energies

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    The amount of proton stopping in central Pb+Pb collisions from 20–160 A GeV as well as hyperon and antihyperon rapidity distributions are calculated within the UrQMD model in comparison to experimental data at 40, 80, and 160 A GeV taken recently from the NA49 collaboration. Furthermore, the amount of baryon stopping at 160A GeV for Pb+Pb collisions is studied as a function of centrality in comparison to the NA49 data. We find that the strange baryon yield is reasonably described for central collisions, however, the rapidity distributions are somewhat more narrow than the data. Moreover, the experimental antihyperon rapidity distributions at 40, 80, and 160 A GeV are underestimated by up to factors of 3—depending on the annihilation cross section employed—which might be addressed to missing multimeson fusion channels in the UrQMD model. Pacs-Nr.: 25.75.2q, 24.10.Jv, 24.10.L

    Baryon stopping and strange baryon/antibaryon production at SPS energies

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    The amount of proton stopping in central Pb+Pb collisions from 20 160 A·GeV as well as hyperon and antihyperon rapidity distributions are calcu- lated within the UrQMD model in comparison to experimental data at 40, 80 and 160 A·GeV taken recently from the NA49 collaboration. Further- more, the amount of baryon stopping at 160 A·GeV for Pb + Pb collisions is studied as a function of centrality in comparison to the NA49 data. We find that the strange baryon yield is reasonably described for central colli- sions, however, the rapidity distributions are somewhat more narrow than the data. Moreover, the experimental antihyperon rapidity distributions at 40, 80 and 160 A·GeV are underestimated by up to factors of 3 - depending on the annihilation cross section employed - which might be addressed to missing multi-meson fusion channels in the UrQMD model. PACS 25.75.+

    Nucleus-nucleus collisions at high baryon densities

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    We study central collision of Pb + Pb at 20, 40, 80 and 160 A·GeV within the UrQMD transport approach and compare rapidity distributions of ,K+,K and with the recent measurements from the NA49 Collaboration at 40, 80 and 160 A·GeV. It is found that the UrQMD model reasonably describes the data, however, systematically overpredicts the yield by < 20%, whereas the K+ yield is underestimated by < 15%. The K yields are in a good agreement with the experimental data, the yields are also in a reasonable correspondence with the data for all energies. We find that hadronic flavour exchange reactions largely distort the information about the initial strangeness production mechanism at all energies considered. PACS: 25.75.+

    Edgeworth and Lindahl-Foley equilibria of a general equilibrium model with private provision of pure public goods

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    In this paper, we propose a definition of Edgeworth equilibrium for a private ownership production economy with (possibly infinitely) many private goods and a finite number of pure public goods. We show that Edgeworth equilibria exist whatever be the dimension of the private goods space, and can be decentralized, in the finite and infinite dimensional cases, as Lindahl-Foley equilibria. Existence theorems for Lindahl-Foley equilibria are a by-product of our results.production economy; public goods; Edgworth equilibrium; Lindahl-Foley equilibrium; proper economy

    Integrated Approach to the Assessment of the Quality of Immunostimulatory Beverage "Immuno Plus"

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    Based on the methods of theoretical qualimetry there was carried out the complex assessment of the quality of immunostimulatory beverage “Immuno plus”. The hierarchic structure of the properties of ready product, including the organoleptic and physical-chemical parameters and also the ones of food and biological value was presented. It was demonstrated, that the improvement of consistence, homogeneity and steadiness of beverage can be explained by gluten that acts as a hydrocolloid and consumers estimate the beverage quality according to these very parameters. The profiles of vitamin and mineral composition of immunostimulatory beverage “Immuno plus” and also the content of irreplaceable acids in it were presented.The received complex parameter of the “Immuno plus” beverage quality proves the high quality of new product. The calculated competitiveness of enriched beverage is 1,5 higher comparing with the control sample. The calculations of competitiveness of the beverage of increased food and biological value according to the modeling method that includes the parameters of the product quality, information about the analogues of elaborated goods and principle of innovations were presented. It was established, that the immunostimulatory beverage “Immuno plus” can be competitive on the Ukrainian consumer market at the expanse of improvement of organoleptic parameters, increase of food fibers, vitamins and mineral substances content in it and also of the presence of prophylactic properties
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