Abstract: In a telecommunications system, automatic directory assistance uses a voice processing unit comprising a lexicon of lexemes and data representing a predetermined relationship between each lexeme and calling numbers in a locality served by the automated directory assistance apparatus. The voice processing unit issues messages to a caller making a directory assistance call to prompt the caller to utter a required one of said lexemes. The unit detects the calling number originating a directory assistance call and, responsive to the calling number and the relationship data computes a probability index representing the likelihood of a lexeme being the subject of the directory assistance call. The unit employs a speech recognizer to recognize, on the basis of the acoustics of the caller's utterance and the probability index, a lexeme corresponding to that uttered by the caller.

Abstract: A flexible vocabulary speech recognition system is provided for recognizing speech transmitted via the public switched telephone network. The flexible vocabulary recognition (FVR) system is a phoneme based system. The phonemes are modelled as hidden Markov models. The vocabulary is represented as concatenated phoneme models. The phoneme models are trained using Viterbi training enhanced by: substituting the covariance matrix of given phonemes by others, applying energy level thresholds and voiced, unvoiced, silence labelling constraints during Viterbi training. Specific vocabulary members, such as digits, are represented by allophone models. A* searching of the lexical network is facilitated by providing a reduced network which provides estimate scores used to evaluate the recognition path through the lexical network. Joint recognition and rejection of out-of-vocabulary words are provided by using both cepstrum and LSP parameter vectors.

Abstract: In an optical time domain reflectometer (OTDR), an optical signal is coupled to an optical fiber path to be tested, and back-scattered and reflected light from the optical fiber path is detected and used to determine loss-distance characteristics of the path. A control unit varies the wavelength of the optical signal by varying the temperature of a semiconductor laser constituting the optical source, so that the loss-distance characteristics for a plurality of different wavelengths are determined and can be displayed to show any wavelength dependent loss of the optical fiber path, which loss may be due to modal interference associated with closely spaced discontinuities in the path.

Abstract: A treatment device and a method for simultaneously applying vibrations and percussion forces to a predetermined area of a patient's body adjacent the lungs of the patient. The device comprises a housing having a handle portion. A clapping head is disposed exteriorly of the housing and connected to a reciprocable element which is imparted a set low frequency reciprocation movement by a low frequency generation device to impart a clapping action to the head. The head has a contact surface for engagement with the predetermined area of the patient's body. An independent vibrator element is also provided and has a body engaging member which is disposed in relation to the clapping head and connected to a vibration generating device capable of vibrating the vibrator element at a higher predetermined frequency than the reciprocation movement of the clapping head. Preferably, the clapping frequency is in the range of from 0.5 Hz to 2 Hz and the vibration frequency is in the range of from 40 Hz to 70 Hz.

Abstract: In a method and apparatus for inhibiting ice mass formation around equipment housed in a chamber subject to water penetration, a plurality of compressible, non-absorbent, smooth-surfaced blocks are packed around the equipment to substantially fill the chamber. The blocks are provided with handles for their placement in and removal from the chamber. The blocks are particularly useful for inhibiting ice mass formation in shallow underground chambers housing telecommunications cable equipment.

Abstract: A wood preservative solution comprising water, hexavalent chromium, copper and arsenic can be stabilized against precipitation by the addition of fluorine ion, thereby enhancing the useful life and safety of the solution. Fluoride salts like cerium fluoride, sodium fluoride and calcium fluoride are suitable sources for fluorine ion in such a solution. Wood treated with the preservative solution displays increased penetration, distribution and retention of chromium, copper and arsenic.

Abstract: A treatment for wood poles, as used for telecommunications and electric power poles, to reduce surface hardening comprises modifying the standard treatment solution by the addition of a polymer of ethylene oxide. A surface active agent is a further possible additive, and reduction of the hexavalent chrome ion in the standard solution is a further modification.