Abstract: The present invention pertains to a concatenative speech synthesis system and method which produces a more natural sounding speech. The system provides for multiple instances of each acoustic unit which can be used to generate a speech waveform representing an linguistic expression. The multiple instances are formed during an analysis or training phase of the synthesis process and are limited to a robust representation of the highest probability instances. The provision of multiple instances enables the synthesizer to select the instance which closely resembles the desired instance thereby eliminating the need to alter the stored instance to match the desired instance. This in essence minimizes the spectral distortion between the boundaries of adjacent instances thereby producing more natural sounding speech.

Abstract: Prosodic databases hold fundamental frequency templates for use in a speech synthesis system. Prosodic database templates may hold fundamental frequency values for syllables in a given sentence. These fundamental frequency values may be applied in synthesizing a sentence of speech. The templates are indexed by tonal pattern markings. A predicted tonal marking pattern is generated for each sentence of text that is to be synthesized, and this predicted pattern of tonal markings is used to locate a best-matching template. The templates are derived by calculating fundamental frequencies on a pursuable basis for sentences that are spoken by a human trainer for a given unlabeled corpus.

Abstract: A method and system for modeling handwriting using polynomials as a function of time. In a preferred embodiment, a user inputs handwriting by writing with an electronic pen on an electronic tablet. The tablet samples the location of the tip of the pen on the tablet from pen down until pen up at periodic intervals as each stroke in a character is written and inputs the (x,y) coordinates for each stroke in the character to a normalizer. The normalizer normalizes the (x,y) coordinates and inputs the normalized (x,y) coordinates to a featurizer. The featurizer generates a set of features that represent each stroke in the character. In the preferred embodiment, the features are coefficients of a Chebyshev. After the Chebyshev coefficients have been generated for each stroke in the character, the featurizer normalizes the set of Chebyshev coefficients. During training, the normalized Chebyshev coefficients are input to a prototype generator.

Abstract: A method and system for conservative-stack and generational garbage collection for a computer memory is provided. In a preferred embodiment, the computer memory includes a stack and a heap. The heap comprises a plurality of objects each of which is identified as new or old. During run time, a list of old objects that contain pointers to new objects is maintained. During garbage collection time, each new object that is accessible through an old object in the list is marked as accessible. The stack contains a plurality of stack entry that may be pointers to new objects. During garbage collection time, each stack entry is checked to see if it could point to a new object. Each new object that a stack entry could point to is marked as accessible and each new object that is accessible through the marked objects is also marked as accessible. During memory compaction, the new objects that are not marked as accessible are reclaimed.

Abstract: A method for a computer compiler for an object-oriented programming language for implementing virtual functions is provided. In preferred embodiments of the present invention, the virtual function table for a class contains a tile table and a plurality of sub-tables. The tile table contains pointers to the sub-tables, and the sub-tables contain pointers to the virtual function members of the class. Each child class shares a sub-table of the parent class when the child class does not override a function in that sub-table. If the child class overrides a function, then the child is allocated its own sub-table. Each virtual function member for a class is identified by a tile table offset and a sub-table offset.

Abstract: This invention discloses novel compounds 3-hydryl-F-oxetane and 3,3-dihydryl-F-oxetane, for use as refrigerants or solvents. The compounds will serve as close replacements for CFC's R-11 and R-113.

Abstract: A digital filter for prewhitening digital noise is realized without the need to perform multiplication or division operations to weight any of the digital samples. Instead, the data samples that need weighting are bit shifted to achieve multiplication or division by a power of two. In the preferred embodiment, the filtering function is 1-z/8, where z is a single sample delay. This function is implemented by bit shifting one sample three bits to the right and computing the difference between it and an adjacent sample.

Abstract: A chirp signal is provided that is characterized by a flat response in the frequency domain. To achieve this response, the signal is made non-flat in the time domain. That is, its amplitude is varied as its frequency is swept. The particular perturbations introduced into the chirp's waveform are typically selected to minimize the waveform's crest factor.

Abstract: A digital mixer is supplied with two digitized input signals in complex form. The product of the complex input signals is converted to analog form and provides the desired output signal without any alias terms. The first input signal is desirably stored in a first memory as a sequence of data points corresponding to a complex exponential sinusoid. The second input signal is a baseband excitation waveform that is also stored in complex form in a memory. Operands from these two sources are provided periodically to the mixer for complex multiplication. The sequence of sinusoid operands provided from the first memory is determined by a phase counter that indexes through the memory by a .DELTA..theta. term. .DELTA..theta. is selected so that the data indexed thereby corresponds to samples of a sine wave of the desired frequency. If .DELTA..theta. indexes a signal phase intermediate two complex data in the memory, an interpolated value is provided.

Abstract: An apparatus for aerosol direct fluorination is disclosed in which a material to be fluorinated is formed into an aerosol prior to fluorination by introducing a vapor stream of the material to be fluorinated centrally into converging flows of carrier particles suspended in a gas and condensing the vapor onto the particles. Fluorine is contacted with the aerosol in an elongated fluorination reactor having microporous walls providing a substantially continuous influx of fluorine-containing gas which creates an increasing fluorine concentration gradient as the aerosol moves through the reactor and provides a barrier to prevent contact of the aerosol with the microporous walls. A photochemical stage includes an elliptical reflector with a light source of one focus and a flow of aerosol and fluorine at the others.

Abstract: A pole and zero analyzer determines the poles and zeroes of a device by applying a stimulus signal to the device, detecting the stimulus and response signals and computing the auto- and cross-spectra. An estimated transfer function is least squares fit to a measured transfer function obtained from the auto- and cross-spectra and the poles and zeroes are obtained as the roots of the estimated transfer function. A weighting function may be used to emphasize certain desired regions of the frequencies of interest in the determination of the least squares fit. The orders of the poles and zeroes are modified until an optimum fit is reached.

Abstract: A pole and zero analyzer determines the poles and zeroes of a device by applying a stimulus signal to the device, detecting the stimulus and response signals and computing the auto- and cross spectra. An estimated transfer function comprising a rational fraction of two Chebyshev polynomials is least squares fit to a measured transfer function obtained from the auto- and cross-spectra and the poles and zeroes are obtained as the roots of the estimated transfer function. Inaccuracies due to noise and computational error are minimized by the use of the Chebyshev polynomials.

Abstract: A contaminant trap for a gas-insulated electrical conductor is provided. A resinous dielectric body such as Kel-F wax, grease or other sticky polymeric or oligomeric compound is disposed on the inside wall of the outer housing for the conductor. The resinous body is sufficiently sticky at ambient temperatures to immobilize contaminant particles in the insulating gas on the exposed surfaces thereof. An electric resistance heating element is disposed in the resinous body to selectively raise the temperature of the resinous body to a molten state so that the contaminant particles collected on the surface of the body sink into the body so that the surface of the resinous body is renewed to a particle-less condition and, when cooled, returns to a sticky collecting surface.

Abstract: Electrical breakdown of a gas insulator in high voltage apparatus is preved by placing an electrical insulative coating on contaminant particles in the gas insulator.

Abstract: An apparatus and process useful in direct fluorination of a variety of compositions, as well as the fluorinated compositions themselves, are disclosed.The apparatus comprises a cryogenic zone reactor, such as a packed column reactor, suitably divided into a plurality of independently controllable cryogenic temperature zones. Means are also provided to introduce a reactant to be fluorinated as well as to introduce a mixture of fluorine gas and an inert gas.New fluorinated compounds are also disclosed. These include: perfluoro-2-methoxyethyl ether; perfluoro-1,4-dioxane; perfluoro-2,5-diketohexane; perfluorohexamethylethane; and monohydropentadecafluoroadamantane.Additionally, new syntheses for trifluoroacetic acid, a commercially significant bulk chemical, are disclosed. One synthesis comprises producing perfluorooethyl acetate by direct fluorination using a cryogenic zone reactor, followed by hydrolysis of perfluoroethyl acetate. Two moles of the acid are produced for each mole of ester.

Abstract: A plastic composite construction and process for its preparation are disclosed in which the composite comprises a plastic core or center of extended surface area. The composite includes a metallic layer on at least one face of the core and an elastomeric layer, such as of a butyl rubber, adhered to an opposite face of the core. The addition of an elastomeric layer converts the composite to an energy-absorbing construction of substantially improved impact resistance which avoids the normal cracking or spalling of the metallic layer upon impact. The present plastic composite may have an impact resistance of at least seven foot pounds at minus 30.degree. F. The plastic composite can be used as an exterior mirror housing and the like for vehicles.

Abstract: A method and apparatus for improving direct fluorinations are disclosed in which the material to be fluorinated is formed into an aerosol prior to fluorination.

Abstract: An apparatus and process useful in direct fluorination of a variety of compositions, as well as the fluorinated compositions themselves, are disclosed.The apparatus comprises a cryogenic zone reactor, such as a packed column reactor, suitably divided into a plurality of independently controllable cryogenic temperature zones. Means are also provided to introduce a reactant to be fluorinated as well as to introduce a mixture of fluorine gas and an inert gas.New fluorinated compounds are also disclosed. These include: perfluoro-2-methoxyethyl ether; perfluoro-1,4-dioxane; perfluoro-2,5-diketohexane; perfluorohexamethylethane; and monohydropentadecafluoroadamantane.Additionally, new syntheses for trifluoroacetic acid, a commercially significant bulk chemical, are disclosed. One synthesis comprises producing perfluoroethyl acetate by direct fluorination using a cryogenic zone reactor, followed by hydrolysis of perfluoroethyl acetate. Two moles of the acid are produced for each mole of ester.

Abstract: Perfluorinated functionalized materials are disclosed which are prepared by simultaneous perfluorination and functionalization. A wide variety of materials can be used including polymers and other branched or straight chain hydrocarbons. The material to be perfluorinated is placed in a direct fluorination apparatus and a mixture of fluorine and oxygen is passed over the material using La-Mar direct fluorination techniques. With materials such as polyethylene or polypropylene, pendant alkyl groups are converted to either acid fluoride groups or perfluoroalkyl groups, with the exact ratio of each being dependent upon the specific fluorine-to-oxygen ratio used.

Abstract: An apparatus and process useful in direct fluorination of a variety of compositions, as well as the fluorinated compositions themselves. The apparatus comprises a cryogenic zone reactor, such as a packed column reactor, divided into a plurality of independently controllable cryogenic temperature zones. Means are also provided to introduce a reactant to be fluorinated as well as to introduce a mixture of fluorine gas and an inert gas. The direct fluorination process is carried out in the reactor as described above. At least the first zone of the reactor is chilled to a temperature below the freezing point of the reactant to be fluorinated. The reactant is then introduced into the reactor wherein it condenses upon a suitably provided fluorination surface, such as copper column packings. A mixture of fluorine gas and an inert gas, with the fluorine gas initially comprising a very small percentage of the mixture, but gradually increasing as fluorination proceeds, is then introduced into the reactor.