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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Journal of the Acoustical Society of Korea
Journal Basic Information
Journal DOI :
The Acoustical Society of Korea
Editor in Chief :
Volume & Issues
Volume 25, Issue 8 - Nov 2006
Volume 25, Issue 7 - Oct 2006
Volume 25, Issue 6 - Aug 2006
Volume 25, Issue 5 - Jul 2006
Volume 25, Issue 2E - Jun 2006
Volume 25, Issue 4 - May 2006
Volume 25, Issue 3 - Apr 2006
Volume 25, Issue 2 - Feb 2006
Volume 25, Issue 1 - Jan 2006
Selecting the target year
Computation of Underwater Acoustic Field Using Acoustic Impedance as an Input Parameter for the Ocean Bottom
Lee Seongwook ; Oh Taekhwan ; Na Jungyul ; Lee Phil-Ho ; Yoon Jong Rak ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 1~6
The Possibility of using acoustic impedance as an input Parameter for computation of underwater acoustic field in shallow waters was investigated. Analysis of the acoustic reflection from the ocean bottom with shear wave effect showed that acoustic impedances below the critical grazing angle have nearly angle-independent property and could be approximated with a single value of near-grazing impedance
. Computations of the Propagation loss based on the concept of 'effective depth' indicate that near-grazing bottom acoustic impedances could be used as an input parameter for simulation of the acoustic fields in shallow waters.
Development of Highly Efficient Underwater Loudspeaker for Attracting and Threatening Fish
Kim Chun-Duck ; Lee Chai-Bong ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 7~13
Fisheries policy change from catching to farming requires more intensive consideration for aquaculture industry. The oceanic farm is a desirable cost effective aquaculture method. However. in odor to gather fish in the oceanic farm, eating sound or any attracting sound should be radiated through underwater loudspeaker. In this Paper, it has been found in literature that the frequency range responding to fish is about 16Hz to 13kHz but sensitive frequency range is about 150Hz to 2kHz and sound pressure level is about 100dB to 150dB reference
. Therefore, frequency range and output sound level of designed underwater loudspeaker has been specified as 150Hz to 3kHz and 100dB to 145dB reference
. respectively To verify the stability and the endurance to the pressure of 40m water depth, manufactured underwater loudspeaker was examined before sea trial in manufactured water pressure tank which gives a maximum of 10 atmospheric Pressure. We experimented on acoustic characteristic with manufactured underwater loudspeaker under water depth of 10m.
Blind Signal Separation Using Eigenvectors as Initial Weights in Delayed Mixtures
Park, Jang-Sik ; Son, Kyung-Sik ; Park, Keun-Soo ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 14~20
In this paper. a novel technique to set up the initial weights in BSS of delayed mixtures is proposed. After analyzing Eigendecomposition for the correlation matrix of mixing data. the initial weights are set from the Eigenvectors ith delay information. The Proposed setting of initial weighting method for conventional FDICA technique improved the separation Performance. The computer simulation shows that the Proposed method achieves the improved SIR and faster convergence speed of learning curve.
Highband Coding Method Using Matching Pusuit Estimation and CELP Coding for Wideband Speech Coder
Jeong Gyu-Hyeok ; Ahn Yeong-Uk ; Kim Jong-Hark ; Shin Jae-Hyun ; Seo Sang-Won ; Hwang In-Kwan ; Lee In-Sung ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 21~29
In this Paper a split bandwidth wideband speech coder and its highband coding method are Proposed. The coder uses a split-band approach. where the wideband input speech signal is split into two equal frequency bands from 0-4kHz and 4-8kHz. The lowband and the highband are coded respectively by the 11.8kb/s G.729 Annex E and the proposed coding method. After the LPC analysis, the highband is divided by two modes according to the properties of signals. In stationary mode. the highband signals are compressed by the mixture excitation model; CELP algorithm and W (Matching Pursuit) algorithm. The others are coded by the only CELP algorithm. We compare the performance of the new wideband speech coder with that of G.722 48kbps SB-ADPCM and G.722.2 12.85kbps in a subjective method. The simulation results show that the Performance of the proposed wideband speech coder has better than that of 48kbps G.722 and no better than that of 12.85kbps G.722.2
A Microphone Array Beamforming Algorithm with Inverse Filtering of Relative Transfer Functions in Car Environments
Kang Hong-Goo ; Hwang Youngsoo ; Youn Dae-Hee ; Han Chul-Hee ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 30~35
In this paper. we Propose a frequency domain beamforming algorithm composed of inverse-filtering stages followed by a MVDR (Minimum-Variance Distortionless Response) beamformer or a GSC (Generalized Sidelobe Canceller). The proposed method is shown to require less complexity than the conventional RTF-MVDR and TF-GSC. respectively, and it is shown that the Proposed method is equivalent to the conventional RTF-MVDR and TF-GSC in optimum solution. In order to evaluate the performance of the Proposed method. speech recognition experiments are performed using the speech database recorded in a car. The Proposed method shows equal or slightly degraded Performance comparing to the conventional methods in terms of the speech recognition rate.
A PCA-based MFDWC Feature Parameter for Speaker Verification System
Hahm Seong-Jun ; Jung Ho-Youl ; Chung Hyun-Yeol ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 36~42
A Principal component analysis (PCA)-based Mel-Frequency Discrete Wavelet Coefficients (MFDWC) feature Parameters for speaker verification system is Presented in this Paper In this method, we used the 1st-eigenvector obtained from PCA to calculate the energy of each node of level that was approximated by. met-scale. This eigenvector satisfies the constraint of general weighting function that the squared sum of each component of weighting function is unity and is considered to represent speaker's characteristic closely because the 1st-eigenvector of each speaker is fairly different from the others. For verification. we used Universal Background Model (UBM) approach that compares claimed speaker s model with UBM on frame-level. We performed experiments to test the effectiveness of PCA-based parameter and found that our Proposed Parameters could obtain improved average Performance of
compared to MFCC.
to LPCC and 6.69 to existing MFDWC.
Vibration Analysis During Breaking Process of Phantom Induced by Shock Wave for Medical Treatment
Park Kyu-Chil ; Jang Yun-Seok ;
The Journal of the Acoustical Society of Korea, volume 25, issue 1, 2006, Pages 43~48
When the vibration of a phantom induced by Extracorporeal Shock Wave Lithotripter (ESWL) was investigated. we found the fact that the Peak frequency in the Power spectrum shifts from high frequency to low frequency as the number of shots increases. The fact was confirmed experimentally by detecting the peak frequency obtained from the vibrations of bronze models. This Paper investigates the experimental results. For the Purpose. we carried out the computer simulation using the finite element method. It is found that the results from the experiments are computer by computer simulation.