Abstract: The present invention relates to a time delay estimation device. The time delay estimation device of the present invention includes a sound signal detection unit configured to detect sound signals through a plurality of microphones, a frequency domain conversion unit configured to convert the detected sound signals into signals of a frequency domain, and a time delay estimation unit configured to estimate a time delay on the basis of a slope of a phase difference between the sound signals converted into the frequency domain.

Abstract: The present invention relates to a time delay estimation device. The time delay estimation device of the present invention includes a sound signal detection unit configured to detect sound signals through a plurality of microphones, a frequency domain conversion unit configured to convert the detected sound signals into signals of a frequency domain, and a time delay estimation unit configured to estimate a time delay on the basis of a slope of a phase difference between the sound signals converted into the frequency domain.

Abstract: The present disclosure provides a distance estimation device, including a wave signal detection unit configured to measure different types of waves, respectively, to detect different wave signals, a time delay estimation unit configured to produce a correlation coefficient from the detected different wave signals, and computes an arrival time difference using the correlation coefficient, and a distance calculation unit configured to estimate the distance of a target object using an arrival time difference for each of the different types of waves.

Abstract: Magnetostrictive transducers for monitoring wall thinning in a pipe, and an apparatus and method for monitoring wall thinning in a pipe using magnetostrictive transducers are provided. The magnetostrictive transducers generate broadband multimode shear horizontal (SH) waves, and allow the generated SH waves to travel along the pipe, thus correctly monitoring a status of the wall thinning of the pipe. The apparatus includes a transmitting transducer which is installed outside of a pipe and generates shear horizontal (SH) waves traveling along the pipe, a receiving transducer which is spaced apart from the transmitting transducer and measures the shear horizontal (SH) waves traveling along the pipe, and a controller for monitoring wall thinning of the pipe by exciting and measuring output signals of the transmitting and receiving transducers.

Abstract: A method and system for predicting acoustic fields based on generalized moving frame acoustic holography are disclosed. The method includes acquiring a first wavenumber spectrum on a measurement plane according to a moving coordinate system, converting the first wavenumber spectrum to a second wavenumber spectrum on a reference coordinate system using a relative velocity between the measurement plane and a medium, converting the second wavenumber spectrum to a third wavenumber spectrum on a prediction plane using an acoustic wave propagation theory, converting the third wavenumber spectrum to a fourth wavenumber spectrum on a moving coordinate system using a relative velocity between the medium and the prediction plane, and computing acoustic fields on the prediction plane using the fourth wavenumber spectrum.

Abstract: Magnetostrictive transducers for monitoring wall thinning in a pipe, and an apparatus and method for monitoring wall thinning in a pipe using magnetostrictive transducers are provided. The magnetostrictive transducers generate broadband multimode shear horizontal (SH) waves, and allow the generated SH waves to travel along the pipe, thus correctly monitoring a status of the wall thinning of the pipe. The apparatus includes a transmitting transducer which is installed outside of a pipe and generates shear horizontal (SH) waves traveling along the pipe, a receiving transducer which is spaced apart from the transmitting transducer and measures the shear horizontal (SH) waves traveling along the pipe, and a controller for monitoring wall thinning of the pipe by exciting and measuring output signals of the transmitting and receiving transducers.

Abstract: A method and system for predicting acoustic fields based on generalized moving frame acoustic holography are disclosed. The method includes acquiring a first wavenumber spectrum on a measurement plane according to a moving coordinate system, converting the first wavenumber spectrum to a second wavenumber spectrum on a reference coordinate system using a relative velocity between the measurement plane and a medium, converting the second wavenumber spectrum to a third wavenumber spectrum on a prediction plane using an acoustic wave propagation theory, converting the third wavenumber spectrum to a fourth wavenumber spectrum on a moving coordinate system using a relative velocity between the medium and the prediction plane, and computing acoustic fields on the prediction plane using the fourth wavenumber spectrum.