1,895 research outputs found
Supplement to "What Model for Entry in First-Price Auctions? A Nonparametric Approach"
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
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
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
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
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
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
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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