6,137 research outputs found
On the perturbative expansion of boundary reflection factors of the supersymmetric sinh-Gordon model
The supersymmetric sinh-Gordon model on a half-line with integrable boundary
conditions is considered perturbatively to verify conjectured exact reflection
factors to one loop order. Propagators for the boson and fermion fields
restricted to a half-line contain several novel features and are developed as
prerequisites for the calculations.Comment: 19 pages, 2 figure
Self-duality in Generalized Lorentz Superspaces
We extend the notion of self-duality to spaces built from a set of
representations of the Lorentz group with bosonic or fermionic behaviour, not
having the traditional spin-one upper-bound of super Minkowski space. The
generalized derivative vector fields on such superspaces are assumed to form a
superalgebra. Introducing corresponding gauge potentials and hence covariant
derivatives and curvatures, we define generalized self-duality as the Lorentz
covariant vanishing of certain irreducible parts of the curvatures.Comment: 6 pages, Late
Estimating the Value Consumers Derive from Product Labeling
Firms spend billions of dollars annually on new product and label designs in order to attract and retain customers. The issue of labeling is also important to government agencies and nonprofit labeling organizations. For example, the U.S. Food and Drug Administration has an organizational body in its Office of Nutritional Products that deals with issues of food and dietary supplement labeling. The U.S. Department of Agriculture’s Food Safety and Inspection Service also deals with labeling through its Labeling and Consumer Protection Staff. These government agencies spend millions of dollars trying to ensure that food labels adequately inform consumers. One issue that has not been examined is the welfare difference to consumers from alternative labeling schemes/regulations. It seems likely that different labels would differ in effectiveness at informing consumers.
Do Practice Rounds Bias Experimental Auction Results?
Consumer/Household Economics,
Consumer Preferences for Fair Trade Foods: Implications for Trade Policy
Food Consumption/Nutrition/Food Safety, International Relations/Trade, Q18, Q51 Effects,
Posted Prices and Bid Affiliation: Evidence from Experimental Auctions
In most experimental auctions, researchers ask participants to bid on the same item in multiple potentially binding rounds, posting the price submitted by the top bidder or bidders after each of those rounds. If bids submitted in later rounds are affiliated with posted prices from earlier rounds, this practice could result in biased value estimates. In this article we discuss the results of an experiment designed explicitly to test whether posted prices affect bidding behavior. We find that for familiar items, high posted prices lead to increased bids in subsequent rounds. Our results have implications for researchers conducting experimental auctions.Experimental Auctions, Posted Prices, Affiliation
The Effect of Initial Endowments in Experimental Auctions
We report the results of an experiment designed to test whether initial endowments affect value estimates elicited from experimental auctions. Comparing bids for one unit of a good, two units of a good, and a second unit of a good when endowed with the first unit, we find that willingness to pay for the second unit of a good is, on average, as much as 75% higher when endowed with the first unit. We go on to advance two theories that could potentially reconcile our results with neoclassical consumer theory.Endowment Effect, Experimental Auctions, Reciprocity, Top-Dog Effect
AJAE Appendix: Posted Prices and Bid Affiliation: Evidence from Experimental Auctions
The material contained herein is supplementary to the article named in the title and published in the American Journal of Agricultural Economics, Volume 88, Number 4, November 2006.Demand and Price Analysis,
Results of free yaw tests of the Mod-O 100 kilowatt wind turbine
Tests were conducted on the Mod-O 100 kW experimental wind turbine to provide data on yaw alignment characteristics of a large horizontal axis wind turbine with its yaw restraint removed (i.e., in free yaw). The wind turbine consisted of a downwind horizontal axis rotor mounted on a tubular tower. Three rotor configurations were tested. Each rotor was teetered, coned 3 deg and tip-controlled. Two of the rotors had pitch-flap coupling or Delta-3, and one rotor had none. The two rotors with Delta-3 differed in the airfoil used in the tip sections. Test results indicate the rotor without pitch-flap coupling did not align closer than 25 deg with the wind, and pitch-flap coupling improved the wind turbine's alignment with the wind. Yaw damping was shown to have a favorable effect on free yaw characteristics. The change in the tip airfoil section was shown to affect the free yaw alignment also. The rotors with Delta-3 were shown to be capable of responding to wind shifts and exhibited stable operating properties
Stall induced instability of a teetered rotor
Recent tests on the 38m Mod-0 horizontal experimental wind turbine yielded quantitative information on stall induced instability of a teetered rotor. Tests were conducted on rotor blades with NACA 230 series and NACA 643-618 airfoils at low rotor speeds to produce high angles of attack at relatively low wind speeds and power levels. The behavior of the rotor shows good agreement with predicted rotor response based on blade angle of attack calculations and airfoil section properties. The untwisted blades with the 64 series airfoil sections had a slower rate of onset of rotor instability when compared with the twisted 230 series blades, but high teeter angles and teeter stop impacts were experienced with both rotors as wind speeds increased to produce high angles of attack on the outboard portion of the blade. The relative importance of blade twist and airfoil section stall characteristics on the rate of onset of rotor unstability with increasing wind speed was not established however. Blade pitch was shown to be effective in eliminating rotor instability at the expense of some loss in rotor performance near rated wind speed
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