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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of the Acoustical Society of Korea
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Journal DOI :
The Acoustical Society of Korea
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Volume & Issues
Volume 30, Issue 8 - Nov 2011
Volume 30, Issue 7 - Oct 2011
Volume 30, Issue 6 - Aug 2011
Volume 30, Issue 5 - Jul 2011
Volume 30, Issue 4 - May 2011
Volume 30, Issue 3 - Apr 2011
Volume 30, Issue 2 - Feb 2011
Volume 30, Issue 1 - Jan 2011
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Hardware Design of Enhanced Real-Time Sound Direction Estimation System
Kim, Tae-Wan ; Kim, Dong-Hoon ; Chung, Yun-Mo ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 115~122
DOI : 10.7776/ASK.2011.30.3.115
In this paper, we present a method to estimate an accurate real-time sound source direction based on time delay of arrival by using generalized cross correlation with four cross-type microphones. In general, existing systems have two disadvantages such as system embedding limitation due to the necessity of data acquisition for signal processing from microphone input, and real-time processing difficulty because of the increased number of channels for sound direction estimation using DSP processors. To cope with these disadvantages, the system considered in this paper proposes hardware design for enhanced real-time processing using microphone array signal processing. An accurate direction estimation and its design time reduction is achieved by means of an efficient hardware design using spatial segmentation methods and verification techniques. Finally we develop a system which can be used for embedded systems using a sound codec and an FPGA chip. According to experimental results, the system gives much faster real-time processing time compared with either PC-based systems or the case with DSP processors.
Improved Minimum Statistics Based on Environment-Awareness for Noise Power Estimation
Son, Young-Ho ; Choi, Jae-Hun ; Chang, Joon-Hyuk ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 123~128
DOI : 10.7776/ASK.2011.30.3.123
In this paper, we propose the improved noise power estimation in speech enhancement under various noise environments. The previous MS algorithm tracking the minimum value of finite search window uses the optimal power spectrum of signal for smoothing and adopts minimum probability. From the investigation of the previous MS-based methods it can be seen that a fixed size of the minimum search window is assumed regardless of the various environment. To achieve the different search window size, we use the noise classification algorithm based on the Gaussian mixture model (GMM). Performance of the proposed enhancement algorithm is evaluated by ITU-T P.862 perceptual evaluation of speech quality (PESQ) under various noise environments. Based on this, we show that the proposed algorithm yields better result compared to the conventional MS method.
Decoupled Location Parameter Estimation of 3-D Near-Field Sources in a Uniform Circular Array using the Rank Reduction Algorithm
Jung, Tae-Jin ; Kwon, Bum-Soo ; Lee, Kyun-Kyung ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 129~135
DOI : 10.7776/ASK.2011.30.3.129
An algorithm is presented for estimating the 3-D location (i.e., azimuth angle, elevation angle, and range) of multiple sources with a uniform circular array (UCA) consisting of an even number of sensors. Recently the rank reduction (RARE) algorithm for partly-calibrated sensor arrays was developed. This algorithm is applicable to sensor arrays consisting of several identically oriented and calibrated linear subarrays. Assuming that a UCA consists of M sensors, it can be divided into M/2 identical linear subarrays composed of two facing sensors. Based on the structure of the subarrays, the steering vectors are decomposed into two parts: range-independent 2-D direction-of-arrival (DOA) parameters, and range-relevant 3-D location parameters. Using this property we can estimate range-independent 2-D DOAs by using the RARE algorithm. Once the 2-D DOAs are available, range estimation can be obtained for each source by defining the 1-D MUSIC spectrum. Despite its low computational complexity, the proposed algorithm can provide an estimation performance almost comparable to that of the 3-D MUSIC benchmark estimator.
Measurement of Rhythmic Similarity for Auditory Memory Game
Kim, Ju-Wan ; Lee, Se-Won ; Park, Ho-Chong ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 136~141
DOI : 10.7776/ASK.2011.30.3.136
In this paper, a method for measuring rhythmic similarity between two sound signals for auditory memory game is proposed. The proposed method analyzes energy fluctuation, the temporal duration of energy peak, the timbre of two signals, and detects beat positions for each signal. Then, it determines the rhythm vector after compensating a difference in tempo and the number of beats between two signals. Finally, a method for rhythmic similarity measurement is defined as a function of the dissimilarity between two rhythm vectors and a difference in the number of beats. The rhythmic similarity measured by the proposed method and that by the subjective listening test are compared, and the correlation of 0.86 between two results is achieved.
Conversion of Image into Sound Based on HSI Histogram
Kim, Sung-Il ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 142~148
DOI : 10.7776/ASK.2011.30.3.142
The final aim of the present study is to develop the intelligent robot, emulating human synesthetic skills which make it possible to associate a color image with a specific sound. This can be done on the basis of the mutual conversion between color image and sound. As a first step of the final goal, this study focused on a basic system using a conversion of color image into sound. This study describes a proposed method to convert color image into sound, based on the likelihood in the physical frequency information between light and sound. The method of converting color image into sound was implemented by using HSI histograms through RGB-to-HSI color model conversion, which was done by Microsoft Visual C++ (ver. 6.0). Two different color images were used on the simulation experiments, and the results revealed that the hue, saturation and intensity elements of each input color image were converted into fundamental frequency, harmonic and octave elements of a sound, respectively. Through the proposed system, the converted sound elements were then synthesized to automatically generate a sound source with wav file format, using Csound.
Heart Sound-Based Cardiac Disorder Classifiers Using an SVM to Combine HMM and Murmur Scores
Kwak, Chul ; Kwon, Oh-Wook ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 149~157
DOI : 10.7776/ASK.2011.30.3.149
In this paper, we propose a new cardiac disorder classification method using an support vector machine (SVM) to combine hidden Markov model (HMM) and murmur existence information. Using cepstral features and the HMM Viterbi algorithm, we segment input heart sound signals into HMM states for each cardiac disorder model and compute log-likelihood (score) for every state in the model. To exploit the temporal position characteristics of murmur signals, we divide the input signals into two subbands and compute murmur probability of every subband of each frame, and obtain the murmur score for each state by using the state segmentation information obtained from the Viterbi algorithm. With an input vector containing the HMM state scores and the murmur scores for all cardiac disorder models, SVM finally decides the cardiac disorder category. In cardiac disorder classification experimental results, the proposed method shows the relatively improvement rate of 20.4 % compared to the HMM-based classifier with the conventional cepstral features.
Dependencies of Group Velocity and Attenuation Coefficient on Structural Properties in Copper and Nickel Foams with an Open-Celled Structure as Trabecular-Bone-Mimicking Phantoms
Kim, Seong-Il ; Lee, Kang-Il ;
The Journal of the Acoustical Society of Korea, volume 30, issue 3, 2011, Pages 158~166
DOI : 10.7776/ASK.2011.30.3.158
In the present study, copper and nickel foams with an open-celled structure as trabecular-bone-mimicking phantoms were used to investigate the dependencies of group velocity and attenuation coefficient on structural properties such as trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) in trabecular bone. The group velocity and attenuation coefficient of the copper and nickel foams were measured by a through-transmission method in water, using a pair of broadband, unfocused transducers with a diameter of 12.7 mm and a center frequency of 1.0 MHz. The separation of the Biot`s fast and slow waves was consistently observed in the ultrasonic signals transmitted through the copper and nickel foams. The group velocities of the copper and nickel foams showed highly positive correlations with Tb.Th and Tb.Sp. The attenuation coefficient of the copper foam showed a highly negative correlation with Tb.Th and Tb.Sp, whereas that of the nickle foam showed a highly positive correlation with Tb.Th and Tb.Sp. These results advance our understanding of those previously reported by other researchers using trabecular bone samples or phantoms.