Abstract: Provided are a method and an apparatus for acquiring a multi-channel sound by using a microphone array. The method estimates positions of sound sources corresponding to sound source signals, which are mixed together, from the sound source signals input via a microphone array; and generates a multi-channel sound source signal by compensating for the sound source signals, based on differences between the estimated positions of the sound sources and a position of a virtual microphone array substituting for the microphone array. By doing so, the multi-channel sound having a stereoscopic effect can be acquired from a plurality of distant sound source signals which are input via the microphone array from a portable sound acquisition device.

Abstract: An audio quality enhancing apparatus and method is provided in which a microphone array has a non-uniform configuration and thus a beam pattern of a desired direction is obtained in a wide range of frequencies including higher frequency bands and lower frequency bands even when the microphone array is relatively small.

Abstract: Provided is a method and apparatus for canceling noise from a sound signal input through a microphone. The method includes filtering a high-frequency signal having a frequency that is higher than a reference frequency and a low-frequency signal having a frequency that is lower than the reference frequency from input signals obtained through a microphone array, obtaining a high-frequency target signal by canceling a noise signal from the filtered high-frequency signal using a beamforming method, obtaining a low-frequency target signal by canceling a noise signal having a phase difference that is different from a phase difference of a target signal from the filtered low-frequency signal, and obtaining a sound source signal from which noise is cancelled, by synthesizing the obtained high-frequency target signal with the obtained low-frequency target signal.

Abstract: An apparatus and method for removing noise are provided. The apparatus includes an acoustic signal input unit configured to comprise three or more microphones including a first microphone as a reference microphone, a second microphone disposed at a position asymmetrical to the first microphone, and a third microphone disposed at a position symmetrical to the first microphone, and an acoustic signal processing unit configured to remove rear noise using acoustic signals received from the first microphone, the second microphone, and the third microphone.

Abstract: An apparatus and method for calibrating gain difference between microphones included in a microphone array are provided. In the gain calibrating apparatus, weights for each frequency component of the acoustic signals, which have been converted into the signals in the frequency domain are calculated. The weights are used to calibrate the acoustic signals such that the plurality of acoustic signals each have the same amplitude while the acoustic signals maintain their individual phase. The amplitudes of the acoustic signals are calibrated by use of the calculated weights. The gain calibrating apparatus calibrates gain in real time while calculating weights for frequency components of the frame of acoustic signals in real time.

Abstract: An apparatus and method reduce noise in a complex spectrum domain to extract a target signal from input signals containing noise and target speech. Noise estimation may be performed through a filter with a filter learning coefficient that is updated according to a prior-signal-to-noise ratio (prior-SNR). Also, noise estimation accuracy may be improved by using confidential weighted scores. The target signal may be extracted by representing candidates of the target signal as at least two circles in the complex spectrum domain using the estimated noise and then geometrically calculating the intersections of the circles.

Abstract: A digital rights management (DRM) apparatus in a mobile terminal includes DRM middleware that makes different types of DRM systems compatible. The DRM middleware includes at least one plug-in module to perform a conversion between different types of DRM contents. A part of the at least one plug-in module is downloaded in real time from a server and is executed. A part of the at least one plug-in module is executed by a server by remote control through a plug-in interface.

Abstract: A method and apparatus for normalizing a histogram utilizing a backward cumulative histogram which can cumulate a probability distribution function in an order from a greatest to smallest value so as to estimate a noise robust histogram. A method of normalizing a speech feature vector includes: extracting the speech feature vector from a speech signal; calculating a probability distribution function using the extracted speech feature vector; calculating a backward cumulative distribution function by cumulating the probability distribution function in an order from a largest to smallest value; and normalizing a histogram using the backward cumulative distribution function.

Abstract: A formant frequency estimation method which is important information in speech recognition by accelerating a spectrum using a pitch frequency, and an apparatus using the method is provided. That is, the formant frequency estimation method includes preprocessing an input speech signal and generating a spectrum by a fast Fourier transforming the preprocessed input speech signal; smoothing the generated spectrum; accelerating the smoothed spectrum; and determining a formant frequency on the basis of the accelerated spectrum.

Abstract: A technology for eliminating or reducing interference sound from a sound signal to extract target sound is provided. Interference sound is modeled using training noise, and mixed source sound is separated using the modeled interference sound. The mixed source sound is separated into target sound and interference sound using a basis matrix of the modeled interference sound.

Abstract: The present invention relates to a diagnostic marker containing ZNF312b gene and the fragment thereof, a diagnostic method for stomach cancer and a screening method for stomach cancer inducers or inhibitors using the same. ZNF312b gene expression is specifically increased in stomach cancer. And the over-expression or the under-expression of the gene affects activation or inhibition of cell proliferation and tumor formation of a stomach cancer cell line and cell proliferation signal transduction system as well to induce stomach cancer at last. Therefore, ZNF312b marker gene can be effectively used for diagnosis of stomach cancer, construction of a stomach cancer animal model, prevention and treatment of stomach cancer and development of a stomach cancer specific anticancer agent.

Abstract: A virtual screen sound source is spatially synchronized with a visual object displayed on a display. A plurality of loudspeaker sets, which each include at least three of a plurality of loudspeakers installed at the periphery of a display, are selected, individual sound sources corresponding to the respective selected loudspeaker sets are generated, and a multi-sound source is generated by overlapping the generated individual sound sources and output through loudspeakers included in the loudspeaker sets.

Abstract: A sound zooming technique synchronized with a moving picture zooming function is disclosed. A signal to control ambient noise and a signal to control a long distance sound are extracted from an audio signal input through a plurality of microphones. A front directivity-emphasized signal is masked using the two signals and a weighted value to control volume.

Abstract: An apparatus for positioning a screen sound source, a method of generating loudspeaker set information for screen sound source positioning, and a method of reproducing a positioned screen sound source are provided. The apparatus and methods relate to a screen sound source positioning technique. A plurality of loudspeakers, each configured to have approximately the same gain, are each disposed proximate to the edge of a display, and a loudspeaker set including at least two of the loudspeakers is selected to position a virtual sound source substantially synchronized with a visual object displayed at a position on the screen of the display. Accordingly, a virtual sound source may be positioned at a certain specific position on the screen of a display without sound source distortion.

Abstract: A method and apparatus for measuring a distance to a sound source. The method includes combining sound source signals input through at least two microphones and generating at least two microphone output signals, and performing an operation on the generated microphone output signals and calculating a distance to a sound source by using the relationship between a result of the operation and a frequency of the input sound source signals. Accordingly, regardless of the strength of a sound source, the distance to a sound source can be measured.

Abstract: A method, medium, and apparatus for extracting a target sound from a mixed sound. The method includes obtaining the mixed signal from a microphone array, generating a first signal which is emphasized and directed toward a target sound source, and a second signal which is suppressed and directed toward the target sound source, calculating a non-linear filter which is adaptive to at least one of an amplitude ratio of the first signal to the second signal in a time-frequency domain, frequencies of the first and second signals, and a ratio of an interference signal to the mixed signal, and filtering the first signal by the non-linear filter.

Abstract: Provided is a method and apparatus for canceling noise from a sound signal input through a microphone. The method includes filtering a high-frequency signal having a frequency that is higher than a reference frequency and a low-frequency signal having a frequency that is lower than the reference frequency from input signals obtained through a microphone array, obtaining a high-frequency target signal by canceling a noise signal from the filtered high-frequency signal using a beamforming method, obtaining a low-frequency target signal by canceling a noise signal having a phase difference that is different from a phase difference of a target signal from the filtered low-frequency signal, and obtaining a sound source signal from which noise is cancelled, by synthesizing the obtained high-frequency target signal with the obtained low-frequency target signal.

Abstract: Provided is a sound source signal filtering method and apparatus. The sound source signal filtering method includes: generating two or more microphone output signals by combining sound source signals input through a plurality of microphones; calculating distances between the microphones and a sound source from which the sound source signals are emitted by using distance relationships according to frequencies of the sound source signals extracted from the generated microphone output signals; and filtering the sound source signals to obtain one or more sound source signals corresponding to a predetermined distance by using the calculated distances. Accordingly, it is possible to obtain only sound source signals emitted from a sound source at a particular distance from the microphone array among a plurality of sound source signals input through the microphone array.

Abstract: A method, medium, and apparatus canceling noise from a mixed sound. The method includes receiving sound source signals including a target sound and noise, extracting at least one feature vector indicating an attribute difference between the sound source signals from the sound source signals, calculating a suppression coefficient considering ratios of noise to the sound source signals based on the at least one extracted feature vector, and canceling the sound source signals corresponding to noise by controlling an intensity of an output signal generated from the sound source signals according to the calculated suppression coefficient. Accordingly, a clear target sound source signal can be obtained.

Abstract: Provided are a method and an apparatus for acquiring a multi-channel sound by using a microphone array. The method estimates positions of sound sources corresponding to sound source signals, which are mixed together, from the sound source signals input via a microphone array; and generates a multi-channel sound source signal by compensating for the sound source signals, based on differences between the estimated positions of the sound sources and a position of a virtual microphone array substituting for the microphone array. By doing so, the multi-channel sound having a stereoscopic effect can be acquired from a plurality of distant sound source signals which are input via the microphone array from a portable sound acquisition device.