Abstract: A method and product are provided for generating a word set for use in locating a document having a type similar to a type of document in a document collection. The method includes selecting multiple documents from the document collection, each document selected including multiple words, and stemming the words in each document selected to obtain multiple stem words. The method also includes determining a word count for each stem word in each document, and clustering the stem words based on the word count of each stem word in each document to obtain a word set. The product includes a storage medium having programmed instructions recorded thereon for performing the method steps.

Abstract: An alarm system is provided for detecting a seismic tremor and for generating an audio and/or visual alarm signal which varies depending upon the magnitude of the seismic tremor. In the preferred form of the invention, the alarm system comprises a free running oscillator having a pair of terminals the capacitive value across which controls the frequency of the oscillator. A fixed oscillator plate is electrically connected to one terminal while a variable position oscillator plate is electrically connected to the other terminal and has an inertial mass secured to it. A spring positioned between the plates urges the variable position capacitor plate away from the fixed plate but still enables the variable position capacitor plate to move in response to a seismic tremor thus varying the capacitive value between the terminals and the frequency of the oscillator. The output from the oscillator is coupled through a phase locked loop circuit which tracks the oscillator output.