2,574 research outputs found

    Monotonic Allocation Schemes in Clan Games

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    Total clan games are characterized using monotonicity, veto power of the clan members, and a concavity condition reflecting the decreasing marginal contribution of non-clan members to growing coalitions.This decreasing marginal contribution is incorporated in the notion of a bi-monotonic allocation scheme, where the value of each coalition is divided over its members in such a way that the clan members receive a higher, and the non-clan members a lower share as the coalitions grow larger.Each core element of a total clan game can be extended to both a population monotonic and a bi-monotonic allocation scheme.In total clan games where the clan consists of a single member (the so-called big boss) the use of the nucleolus as an allocation mechanism gives rise to a bi-monotonic allocation scheme.cooperative games;population monotonic allocation scheme;bi-monotonic allocation scheme;clan games;big boss games

    Cost allocation in shortest path games

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    A class of cooperative games arising from shortest path problems is dened These shortest path games are shown to be totally balanced and allow a population monotonic allocation scheme Possible methods for obtaining core elements are indicated rst by relating to the allocation rules in taxation and bankruptcy problems second by constructing an explicit rule that takes opportunity costs into account by considering the costs of the second best alternative and that rewards players who are crucial to the construction of the shortest path Finally noncooperative games arising from shortest path problems are introduced in which players make bids or claims on paths The core allocations of the cooperative shortest path game coincide with the payo vectors in the strong Nash equilibria of the associated noncooperative shortest path gam

    Chitinozoans from the Ordovician-Silurian Boundary Beds in the Eastern Cincinnati Region in Ohio and Kentucky

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    Author Institution: Geological Survey of Sweden ; Department of Geology and Mineralogy, The Ohio State UniversityRepresentatives of seven species of chitinozoans, one of which is new (Ancyrochitina belfastensis n. sp.), were isolated from samples of the lowermost Silurian Belfast Member and of slightly younger beds of the Brassfield Formation and of the Upper Ordovician Preachersville Member of the Drakes Formation at two localities in southern Ohio and north-central Kentucky in an attempt to determine the size of the stratigraphic gap at the Ordovician-Silurian paraconformity. Based on comparisons with successions in Estonia and on Anticosti Island, Quebec, the chitinozoans suggest that the stratigraphic gap between the systems, which is likely to be due to a global sea level drop associated with the Gondwana glaciation, represents an interval from the Ashgillian D. complanatus Zone to the early Llandoverian C. cyphus Zone and hence corresponds to about four graptolite zones. The present study is the first record of Silurian chitinozoans from Ohio

    Electrically tunable GHz oscillations in doped GaAs-AlAs superlattices

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    Tunable oscillatory modes of electric-field domains in doped semiconductor superlattices are reported. The experimental investigations demonstrate the realization of tunable, GHz frequencies in GaAs-AlAs superlattices covering the temperature region from 5 to 300 K. The orgin of the tunable oscillatory modes is determined using an analytical and a numerical modeling of the dynamics of domain formation. Three different oscillatory modes are found. Their presence depends on the actual shape of the drift velocity curve, the doping density, the boundary condition, and the length of the superlattice. For most bias regions, the self-sustained oscillations are due to the formation, motion, and recycling of the domain boundary inside the superlattice. For some biases, the strengths of the low and high field domain change periodically in time with the domain boundary being pinned within a few quantum wells. The dependency of the frequency on the coupling leads to the prediction of a new type of tunable GHz oscillator based on semiconductor superlattices.Comment: Tex file (20 pages) and 16 postscript figure

    The effect of dopaminergic medication on beat-based auditory timing in Parkinson’s disease

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    Parkinson’s disease (PD) adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the ‘beat’ in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication), and unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms), or did not (metric complex rhythms), as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only). The second task was the Beat Alignment Test (BAT), in which participants listened to music with regular tones superimposed, and responded as to whether the tones were ‘on’ or ‘off’ the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients.Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased) when ON vs. OFF medication. Performance also worsened with disease severity. For the Beat Alignment Test, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic medication influences beat-based and non-beat-based timing differently. Judging the beat in music does not appear to be affected by PD or by dopaminergic medication
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