BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Detecting radiological anomalies - James Scott (University of Texa
 s at Austin)
DTSTART:20170706T100000Z
DTEND:20170706T104500Z
UID:TALK73174@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:Radiologically active materials are used widely in industry\, 
 medicine\, and research. Yet an unsecured\, lost\, or stolen radiological 
 source can present a major threat to public safety. &nbsp\;To deal with th
 e potential environmental and security hazards posed by such a scenario\, 
 govenment agencies use various detection procedures at ports of entry to t
 heir countries. &nbsp\;Moreover\, security agencies that try to prevent te
 rrorist attacks are keenly interested in the problem of identifying and lo
 cating stolen or smuggled radiation samples. Even at the local level\, pol
 ice departments have shown increasing interest in the deployment of system
 s for detecting anomalous radiological sources.<br><br>Statistically speak
 ing\, the radiological anomaly-detection problem is one of detecting a cha
 nge in distribution. Sequential data is collected from a sensor that measu
 res the energies of arriving gamma rays. These observed energies are rando
 m variables drawn from an energy spectrum\, which is a probability distrib
 ution over the set of possible gamma-ray energies. The question is whether
  those measured energies are from the normal background spectrum\, and the
 refore harmless\, or whether they are from an anomalous spectrum due to th
 e presence of a nearby radiological source. &nbsp\;In this talk I will des
 cribe some new statistical methods we&rsquo\;ve developed for deal with tw
 o major challenges in this setting: 1) characterizing the spatially varyin
 g background radiation in dense urban areas\; and 2) flagging anomalous re
 adings from spatially distributed sensor networks in a statistically rigor
 ous way.<br><br>This is joint work with Wesley Tansey\, Oscar Padilla\, Al
 ex Reinhart\, and Alex Athey.<br>
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR