A Note on Revenue Effects of Asymmetry in Private-Value Auctions

We formulate a way to study whether the asymmetry of buyers (in the sense of having different prior probability distributions of valuations) is helpful to the seller in private-value auctions (asked first by Cantillon [2001]). In our proposed formulation, this question corresponds to two important questions previously asked: Does a first-price auction have higher revenue than a second-price auction when buyers have asymmetric distributions (asked by Maskin and Riley[2000])? And does a seller enhance revenue by releasing information (asked by Milgrom and Weber[1982])? This is shown by constructing two Harsanyi games of incomplete information each having the same ex-ante distribution of valuations but in one beliefs are symmetric while in the other beliefs are sometimes asymmetric. Our main result is that answers to all three questions coincide when values are independent and are related when values are affiliated.Asymmetric Auctions; Asymmetric Beliefs; Affiliation; Linkage Principle

Multiple equilibria in asymmetric first-price auctions

Maskin and Riley (2003) and Lebrun (2006) prove that the Bayes-Nash equilibrium of �rst-price auctions is unique. This uniqueness requires the assumption that a buyer never bids above his value. We demonstrate that, in asymmetric �rst-price auctions (with or without a minimum bid), the relaxation of this assumption results in additional equilibria that are "substantial." Although in each of these additional equilibria no buyer wins with a bids above his value, the allocation of the object and the selling price may vary among the equilibria. Furthermore, we show that such phenomena can only occur under asymmetry in the distributions of values.Asymmetric auctions, �first-price auctions, multiple equilibria

Physiochemical changes in tissue of edible oyster Crassostrea glomerata at refrigerated temperature

Oysters are bivalve molluscs in the family Osteridae of the order Ostereoida and are found throughout the world. Quality of stored muscle of oyster, Crossostrea glomerata depends on the temperature and storage time. Investigation on factors responsible for spoilage of oyster meat in refrigerator (7±2°C); in term of biochemical indices, indicated that in 1-2 days the following changes will accur: oyster tissue total protein from 7.6±0.44g% to 7.06±0.64g%, salt soluble protein from 3A6±0.52mg% to 2.53±0.14g%.Totallipid from 3.0±0.38g% to 2.5±0.29g%, TMA from 1.1±0.11 mg% to 1.46±0.09 and TVB, from 946±0.29mg% to 19.33±0.06 and on 7th day of storage, total protein to 4.5±0.32g%, salt soluble protein to 1.1±0.21g%, total lipid to 1.4±0.19g%, TMA, to 4.3±0.41 mg% and TVB to 83.3±3.5 changed. Amount of Glycogen in fresh meat was 5.3g% which decreased to 3.2g% during 7 days storage. Water content in fresh tissue was 79.0±0.57g% and increased at 7±2°C gradually with the increase of storage time. After 7 days it reached to the highly significant (p<0.001) value of 89.1±0.54g%.pH in fresh tissue was also noted 6.60±0.17and slightly non significant change was observed during 7 days of storage. On the 7th day it decreased to 6.3±0.05 from its fresh tissue value significantly (p£0.001) with storage time. Results concluded that oyster meat could be preserved for 4 days up to acceptable refrigeration temperature

Asymmetric first-price auctions with uniform distributions: Analytic solutions to the general case

Draft version dated December 25, 2007 originally deposited in SSRN working paper series. Final version published by Springer; available online at http://www.springer.com/While auction research, including asymmetric auctions, has grown significantly in recent years, there is still little analytical solutions of first-price auctions outside the symmetric case. Even in the uniform case, Griesmer et al. (1967) and Plum (1992) find solutions only to the case where the lower bounds of the two distributions are the same. We present the general analytical solutions to asymmetric auctions in the uniform case for two bidders, both with and without a minimum bid. We show that our solution is consistent with the previously known solutions of auctions with uniform distributions. Several interesting examples are presented including a class where the two bid functions are linear. We hope this result improves our understanding of auctions and provides a useful tool for future research in auctions

The THUMOS Challenge on Action Recognition for Videos "in the Wild"

Automatically recognizing and localizing wide ranges of human actions has crucial importance for video understanding. Towards this goal, the THUMOS challenge was introduced in 2013 to serve as a benchmark for action recognition. Until then, video action recognition, including THUMOS challenge, had focused primarily on the classification of pre-segmented (i.e., trimmed) videos, which is an artificial task. In THUMOS 2014, we elevated action recognition to a more practical level by introducing temporally untrimmed videos. These also include `background videos' which share similar scenes and backgrounds as action videos, but are devoid of the specific actions. The three editions of the challenge organized in 2013--2015 have made THUMOS a common benchmark for action classification and detection and the annual challenge is widely attended by teams from around the world. In this paper we describe the THUMOS benchmark in detail and give an overview of data collection and annotation procedures. We present the evaluation protocols used to quantify results in the two THUMOS tasks of action classification and temporal detection. We also present results of submissions to the THUMOS 2015 challenge and review the participating approaches. Additionally, we include a comprehensive empirical study evaluating the differences in action recognition between trimmed and untrimmed videos, and how well methods trained on trimmed videos generalize to untrimmed videos. We conclude by proposing several directions and improvements for future THUMOS challenges.Comment: Preprint submitted to Computer Vision and Image Understandin