1,895 research outputs found

    Supplement to "What Model for Entry in First-Price Auctions? A Nonparametric Approach"

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    The paper contains supplemental material for Marmer, Shneyerov, and Xu (2010) "What Model for Entry in First-Price Auctions? A Nonparametric Approach."

    What Model for Entry in First-Price Auctions? A Nonparametric Approach

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    We develop a nonparametric approach that allows for discrimination among alternative models of entry in first-price auctions. Three models of entry are considered: those of Levin and Smith (1994), Samuelson (1985), and a new model in which the information received at the entry stage is imperfectly correlated with bidder valuations. We derive testable restrictions of these models based on how the pro-competitive selection effect shifts bidder valuation quantiles in response to an increase in the number of potential bidders.First-price auctions, models of entry, selective entry, selection effect, nonparametric estimation, quantiles

    On the Asymptotic Distribution of the Transaction Price in a Clock Model of a Multi-Unit, Oral, Ascending-Price Auction within the Common-Value Paradigm

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    Using a clock model of a multi-unit, oral, ascending-price auction, within the commonvalue paradigm, we analyse the asymptotic behaviour of the transaction price as the number of bidders gets large. We find that even though the transaction price is determined by a (potentially small) fraction of losing drop-out bids, that price converges in probability to the ex ante unknown, true value. Subsequently, we derive the asymptotic distribution of the transaction price. Finally, we apply our methods to data from an auction of taxi license plates held in Shenzhen, China.common value, information aggregation, multi-unit auctions, taxis

    On the Asymptotic Distribution of the Transaction Price in a Clock Model of a Multi-Unit, Oral, Ascending-Price Auction within the Common-Value Paradigm

    Get PDF
    Using a clock model of a multi-unit, oral, ascending-price auction, within the commonvalue paradigm, we analyse the asymptotic behaviour of the transaction price as the number of bidders gets large. We find that even though the transaction price is determined by a (potentially small) fraction of losing drop-out bids, that price converges in probability to the ex ante unknown, true value. Subsequently, we derive the asymptotic distribution of the transaction price. Finally, we apply our methods to data from an auction of taxi license plates held in Shenzhen, China.common value; information aggregation; multi-unit auctions; taxis

    DEVELOPMENT OF AN ADVANCED HIGH PRESSURE RATIO TRANSONIC FAN STAGE. PART-I: DESIGN AND ANALYSIS

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    A high performance fan stage of pressure ratio 2.0 is being designed and developed under a joint programme between Chinese Aeronautical Establishment (CAE) China and National Aerospace Laboratories (NAL), Bangalore, India.. Special features of the aerodynamic design are i) forward blade sweep and lean to increase the ability to bear intake distortion ii) reverse camber fan tip to reduce losses via pre compression iii) low aspect ratio of the blades to maximize stall margin. The blade will be fabricated using laminates of Carbon/Epoxy composites with tip shroud so as to limit the blade stress and deformation. Stress analysis was carried out using MSC/NASTRAN Finite Element Package. The fan stage has undergone a series of design improvements. Comparison of typical results obtained at NAL and BUAA is shown for the final version of the fan stage TTT98-29

    Three-dimensional numerical study of flow characteristic and membrane fouling evolution in an enzymatic membrane reactor

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    In order to enhance the understanding of membrane fouling mechanism, the hydrodynamics of granular flow in a stirred enzymatic membrane reactor was numerically investigated in the present study. A three-dimensional Euler-Euler model, coupled with k-e mixture turbulence model and drag function for interphase momentum exchange, was applied to simulate the two-phase (fluid-solid) turbulent flow. Numerical simulations of single- or two-phase turbulent flow under various stirring speed were implemented. The numerical results coincide very well with some published experimental data. Results for the distributions of velocity, shear stress and turbulent kinetic energy were provided. Our results show that the increase of stirring speed could not only enlarge the circulation loops in the reactor, but it can also increase the shear stress on the membrane surface and accelerate the mixing process of granular materials. The time evolution of volumetric function of granular materials on the membrane surface has qualitatively explained the evolution of membrane fouling.Comment: 10 panges, 8 figure

    Harnessing Geometric Frustration to Form Band Gaps in Acoustic Channel Lattices

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    We demonstrate both numerically and experimentally that geometric frustration in two-dimensional periodic acoustic networks consisting of arrays of narrow air channels can be harnessed to form band gaps (ranges of frequency in which the waves cannot propagate in any direction through the system). While resonant standing wave modes and interferences are ubiquitous in all the analyzed network geometries, we show that they give rise to band gaps only in the geometrically frustrated ones (i.e. those comprising of triangles and pentagons). Our results not only reveal a new mechanism based on geometric frustration to suppress the propagation of pressure waves in specific frequency ranges, but also opens avenues for the design of a new generation of smart systems that control and manipulate sound and vibrations
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