TORNADO STRIKES SWIFTLY-MOVING TRAIN

Do Causes Crowd Each Other Out? Evidence From Tornado Strikes

Does charitable giving respond to new demands, and if so, does the response come at the expense of other charitable causes? To answer these questions we exploit exogenous variation in need arising from the random event of a nearby tornado. We use location fixed effects estimators and examine changes in charitable donations claimed for tax deductions in IRS data on individual income taxes by geo...

Identifying Reliable Workers Swiftly

We study the evaluation and replacement of workers in a crowdsourcing system. We focus on evaluation based on result disagreement among workers, and on policies that replace low accuracy workers with fresh ones from a large pool. We study how long it takes the system to identify an active set of high accuracy workers, and the achieved accuracy of the selected workers. We study through simulatio...

Daily variation in natural disaster casualties: information flows, safety, and opportunity costs in tornado versus hurricane strikes.

Casualties from natural disasters may depend on the day of the week they strike. With data from the Spatial Hazard Events and Losses Database for the United States (SHELDUS), daily variation in hurricane and tornado casualties from 5,043 tornado and 2,455 hurricane time/place events is analyzed. Hurricane forecasts provide at-risk populations with considerable lead time. Such lead time allows s...

Application of the Fractional Fourier Transform to Moving Train Imaging

This paper introduces an imaging algorithm with application of fractional Fourier transform (FrFT) for ground moving train imaging by Ku-band ground-based radar. In view of the fact that the train speed is varying when acrossing the radar beam, the multiple Doppler parameters are estimated corresponding to different range positions, i.e., they are estimated from different sections of data in Fr...

Tornado Warnings and Tornado Fatalities : The Case of May 22 , 2011 Tornado in Joplin , Missouri