Topic detection and tracking approaches monitor broadcast news in order to spot new, previously unreported events and to track the development of the previously spotted ones. The dynamical nature of the events makes the use of state-of-the-art methods difficult. We present a new topic definition that has potential to model evolving events. We also discuss incorporating ontologies into the simil...

We describe a topic tracking system developed at GE R&D Center in connection with our participation in DARPA TDT evaluations. The TDT tracking task is specified as follows: given Nt training news stories on a topic, the system must find all subsequent stories on the same topic in all tracked news sources. These sources include radio and television news broadcasts, as well as newswire feeds. The...

We extend the event tracking task of Topic Detection and Tracking (TDT) to create a framework in which a user can highlight relevant passages in addition to specifying the relevance of documents. A dual framework of combined document and passage feedback improves performance over a state-of-the-art system without feedback by over 70% . Although annotators vary in the content and length of the p...

In order to investigate the theory of the time domain reflectometry (TDR) cable length measurement, the transmission line transient analysis iteration formula based on the finite difference time domain (FDTD) is derived based on the transmission line theory. The electromagnetic wave propagation theory and the regular pattern of the TDR signal propagating in cables are studied. The theoretical c...

Summary: We present a new optical frequency domain reflectometry technique which permits high frequency sweep repetition rates without sacrificing range. This technique could thus be adapted for remote and distributed acoustic sensing over long