@COMMENT This file was generated by bib2html.pl version 0.94 @COMMENT written by Patrick Riley @COMMENT This file came from Gal A. Kaminka's publication pages at @COMMENT http://www.cs.biu.ac.il/~galk/publications/ @PhdThesis{dorit-phd, author = {Dorit Avrahami-Zilberbrand}, title = {Efficient Hybrid Algorithms for Plan Recognition and Detection of Suspicious and Anomalous Behavior }, school = {{B}ar {I}lan {U}niversity}, year = {2009}, OPTkey = {}, OPTtype = {}, OPTaddress = {}, OPTmonth = {}, OPTnote = {}, abstract = { Plan recognition is the process of inferring other agents' plans and goals based on their observable actions. Modern applications of plan recognition, in particular in surveillance and security raise several challenges. First, a number of key capabilities are missing from all but a handful of plan recognizers: (a) handling complex multi-featured observations; (b) dealing with plan execution duration constraints; (c) handling lossy observations (where an observation is intermittently lost); and (d) handling interleaved plans. Second, essentially all previous work in plan recognition has focused on recognition accuracy itself, with no regard to the use of the information in the recognizing agent. As a result, low-likelihood recognition hypotheses that may imply significant meaning to the observer, are ignored in existing work. In this work we present set of efficient plan recognition algorithms that are capable of handling the variety of features required of realistic recognition tasks. We also present novel efficient algorithms that allow the observer to incorporate her own biases and preferences---in the form of a utility function---into the plan recognition process. This allows choosing recognition hypotheses based on their expected utility to the observer. We call this Utility-based Plan Recognition (UPR). We demonstrate the efficacy of the techniques described above, by applying them to the problem of detecting anomalous and suspicious behavior. The system contains the symbolic plan recognition algorithm, which detects anomalous behavior, and the utility-based plan recognizer which reasons about the expected cost of hypotheses. These two components form a highly efficient hybrid plan recognizer capable of recognizing abnormal and potentially dangerous activities. We evaluate the system with extensive experiments, using real-world and simulated activity data, from a variety of sources. }, wwwnote = {}, OPTannote = {} }