Abstract:
The present invention relates to a process of hydrogenation reaction of 2,6-naphthalenedicarboxylic acid comprising the steps of calculating an amount of hydrogen to remove impurities such as formylnaphthoic acid, naphthalenecarboxylate bromide and high molecule organic impurities of heavy substances, and inputting a fixed quantity of hydrogen calculated. Consequently, higher purity 2,6-naphthalenedicarboxylic acid may be obtained in high yield.
Abstract:
In order to detect a degree of voicing of a speech signal, an input speech signal is converted to a speech signal in the frequency domain, a pitch value is calculated from the speech signal, a plurality of harmonic peaks existing in the speech signal are detected, and a difference obtained by comparing the pitch value to an interval between adjacent harmonic peaks among the detected harmonic peaks is detected as the degree of voicing included in the speech signal.
Abstract:
Disclosed is a function of applying a speech signal to a harmonic codec without distinguishing a voiced signal from an unvoiced signal. A peak portion having harmonic and non-harmonic components is extracted from a speech signal based on morphology, and a characteristic frequency is extracted from the extracted peak portion and applied to a harmonic codec. The harmonic codec is a general sinusoidal codec applied to all speech signals. Accordingly, a morphology-based pre-processing method for extracting a characteristic frequency can be easily applied to other speech signal characteristic extracting methods, and performance of other systems using the morphology-based pre-processing method is significantly increased due to a characteristic of a pre-processed signal.
Abstract:
An apparatus and method for extracting pitch information from a speech signal. The apparatus includes a pilot pitch detector for extracting predicted pitch information from a frame of an input speech signal, a pitch candidate value selector for selecting one or more pitch candidate values from the predicted pitch information according to a predetermined condition, a harmonic-noise region decomposer for decomposing a harmonic-noise region using each of the selected pitch candidate values, a harmonic-noise energy ratio calculator for calculating an energy ratio of each of the decomposed harmonic regions to each of the decomposed noise regions, and a pitch information selector for selecting a pitch candidate value of a harmonic-noise region in which the maximum value among the calculated harmonic-noise energy ratio exists as a pitch value of the input frame of the speech signal.
Abstract:
A method of correctly segmenting phonemes by determining a boundary indicating a start point and an end point of each of the segmented phonemes, and correctly finding the phoneme in the speech signal by determining which phoneme in a phoneme recognition standard table corresponds to each of the segmented phonemes. Using this phoneme recognition method, an amount of computation can be significantly reduced, and the phoneme in the speech signal can be easily found by calculating probability distances between phonemes.
Abstract:
The present invention relates to a semiconductor based parabolic waveguide-type collimating lens and a monolithically integrated type tunable external cavity laser diode light source. The monolithically integrated type tunable external cavity laser diode light source includes a gain medium for generating a gain of an optical signal, a collimating lens for correcting an divergent light beam to a parallel light beam, a passive waveguide through which the parallel light beam travels, an optical deflector to change a traveling direction of the parallel light beam changing a refractive index of medium on a traveling path of the parallel light beam traveling through the slab waveguide in response to an external electric signal and a diffraction grating to diffract the parallel light beam passing through the optical deflector, wherein these are integrate into one substrate made of an InP-based semiconductor as well as a material such as a GaAs-based semiconductor, a Si-based semiconductor, LiNbO3-based semiconductor or the like.
Abstract:
A bidirectional add/drop multiplexer includes first input/output unit inputs a first optical signal multiplexed from a plurality of odd channels and outputs a second optical signal multiplexed from a plurality of added or dropped even channels; a second input/output unit outputs the first optical signal multiplexed from a plurality of added or dropped odd channels and outputs the second optical signal multiplexed from a plurality of even channels; an optical arrayed waveguide grating for multiplexing added or dropped odd channels of the first optical signal input to a first terminal for subsequent transmission to the second input/output unit, multiplexing added or dropped even channels of the second optical signal input to a second terminal for subsequent transmission to the first input/output unit; and an optical combining unit that amplifies the first optical signal and the second optical signal input from the first input/output unit and the second input/output unit.
Abstract:
An optical modulator using a dynamic single mode laser diode (DSM-LD) integrated with a deflector is disclosed. The optical modulator for coupling a light beam to an optical fiber, the optical modulator includes: a laser diode for generating the light beam; and a deflector for deflecting a direction of the light beam according to an electric signal externally applied and outputting the defected light beam to the optical fiber, wherein the laser diode and the deflector are integrated with a multi-layer semiconductor structure in such a way that the light beam is modulated by changing a defection angle of the deflector.
Abstract:
A wet-type image forming apparatus includes an intermediate transfer medium for receiving images which are formed in a plurality of photosensitive media and overlapped thereon to form an image and transferring the image to a print medium. The intermediate transfer medium runs along a predetermined path. A drying unit heats the intermediate transfer medium to evaporate part of carrier included in the image on the intermediate transfer medium before the image is transferred onto the print medium. A cooling unit cools the heated intermediate transfer medium after the image is transferred onto the print medium by making the intermediate transfer medium directly contact a coolant.
Abstract:
A wideband optical module includes a downward wideband light source for generating downward light, an upward wideband light source for generating upward light, a first circulator including a first to a third port for outputting multiplexed downward optical signals to the second port and for outputting multiplexed upward optical signals to the first port, a second circulator including a first to a third port for outputting multiplexed upward optical signals to the second port and for outputting multiplexed downward optical signals to the first port, a first optical coupler connected to the third port of the first circulator and the second port of the second circulator for outputting the downward light to the third port of the first circulator, and a second optical coupler connected to the second port of the first circulator and the third port of the second circulator for outputting the upward light to the third port of the second circulator.