STATISTICS SEMINAR :: Estimation of Poisson Intensity in the Presence of Deadtime

GUEST LECTURER
Professor Grace L. Yang

AFFILIATION
DMS/NSF and Department of Mathematics, University of Maryland, College Park

ABSTRACT
Occurrence of dead time in recording instruments poses challenging problems in data acquisition and statistical analysis. Well known examples are signals recorded by the Geiger counter and the electron multiplier. In this presentation, we consider statistical analysis of recordings from the Phase Doppler Interferometry (PDI). PDI is a non-intrusive technique for obtaining information about spray characteristics in many areas of science, including liquid fuel spray in combustion, spray coatings, fire suppression and pesticide dispensing. PDI can record the velocity of individual droplets in a spray. But it will miss some of the droplets because of a recurring presence of dead time. The incompleteness of the PDI recordings results in a multimodal interarrival time distribution of droplets. Modeling a spray process as a homogeneous Poisson process, we estimate the spray diffusion rate (Poisson intensity) with a correction for dead time under various conditions. The asymptotic distribution of the estimates is derived from a strict stationary process. Simulation produced a good agreement between our estimates (in the presence of dead time) and the MLE obtained without dead time. Experimental data from NIST are used for illustration.

DATE & TIME
Friday, November 17, 2006 -- 12:00 PM

DURATION
1 hour

LOCATION
Executive classroom of Main building of ISyE, GT

CONTACT PERSON
Yajun Mei