HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Artificial Intelligence, Fuzzy Logic and Controlnatural languages occurs because the meaning of a sentence is influencedby the context around the sentence.A very basic natural language understanding system can be builtfrom a 1,000-word, speaker-independent system. A more complete systemfor natural language understanding would use a 10,000-word vocabulary.Voice RecognitionEarly voice recognition depended on voice prints which are digitalrecordings of short parts of speech. These prints were analyzed for thelength of a word and for the frequencies used in the word. Each voiceprint acted like a fingerprint and had to be memorized for every personthat the computer would receive voice input from.As the number of words in the vocabulary grows and the numberof persons using the system increases, the amount of memory requiredfor storing the voice prints expands and the time needed to search thevoice prints for a match goes up. Voice print systems tend to be impracticalfor handling large vocabularies.Another type of voice recognition uses phonics to recognize words.This requires storing the known phonemes of speech for a particularlanguage. These phonemes are the smallest units of speech that distinguishone utterance from another.Each word in the vocabulary is represented by these phonemes.When a voice input is received, the input is broken down into a stringof phonemes and the computer makes its best guess at matching theutterances to the phonemes. The computer must also recognize thebreaks between each word.The computer takes the string of received phonemes and comparesthem to known word phoneme patterns. The computer may ask for themeaning of a new word or for repronounication of the word. If it is anew word, the computer will add the phonemes and definition to itsdictionary.Humans increase the speed of their speech processing by assumingwhat they expect to hear. This technique occasionally leads to mistakesand the hearer may have to ask for part of the speech to be repeated. Allof a person’s past experiences are used for reference in speech processing.©2001 by The Fairmont Press, Inc. All rights reserved.