Massachusetts Institute of Technology

Empower Corporation

United States of America As Represented by the Secretary of the Air Force

David H Staelin

Jeffrey Hastings Lang

Carlos R Cabrera-Mercader

Pitch-synchronous speech processing invention involves two main steps: 1) divide the speech into pitch periods, or into pseudo pitch periods for unvoiced speech, where the breaks occur, for example, at the first zero-crossing preceding each glottal pulse for voiced speech and at any arbitrary point for unvoiced speech, and 2) compute the log-magnitude of the Discrete Fourier Transform (DFT) of each pitch-period waveform, and interpolate each log-magnitude spectrum to a common regular grid which can accommodate the spectrum of a waveform having the longest pitch period anticipated.

Pitch-synchronous speech processing

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Powered skateboard

A cathode ray tube apparatus uses a ribbon electron beam to illuminate one line of information at a time on the display surface of the tube. The resulting increase in scanning speed allows for a reduced beam current density and corresponding reduction in electrostatic spreading. The beam is focusable to a smaller spot which allows enhanced image resolution. Velocity filters enhance resolution in the plane of the ribbon beam. A linear modulation assembly allows the ribbon beam to be modulated prior to deflection, removing the need for a full modulation grid. Thin septa are provided to support the tube against compressive external forces. The septa are tapered near the display surface where septum electrodes draw electrons of the beam toward the septa near the display surface to prevent image discontinuity. Rapidly-varying high voltages are provided by an electron gun directed toward receiving anodes which absorb electron energy and transfer resulting voltages to storage circuits which service high voltage electrodes.

Ribbon beam cathode ray tube

A visual display device is disclosed in which a liquid crystal cell is adjacent a light waveguide. Electrodes in the liquid crystal cell alter the dielectric constant therein to change the critical angle defined by the two media of the cell and the waveguide to regulate the amount and location of light which may escape from the waveguide. Color display can be obtained with visible light by providing a dyed layer and with ultraviolet light by providing colored ultraviolet phosphors. A shaped mirror or contoured reflective layer is provided with a visible light device to cause the displayed light to scatter in desired directions.

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Wellesley, MA, United States of America

David H Staelin