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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
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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
Selecting the target year
Measurement System for Performance Evaluation of Acoustic Materials in a Small Water Tank
Shin, Mi-Ru ; Cho, Jung-Hong ; Lee, Kyung-Teak ; Kim, Jea-Soo ; Jeon, Jae-Jin ; Ham, Il-Bea ; Kang, Chang-Gi ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 63~72
DOI : 10.7776/ASK.2011.30.2.063
Since the detection probability is critically dependent on the target strength (TS) in active sonar and on the radiated noise level (RNL) in passive sonar, the acoustic materials for echo reduction (ER) and transmission loss (TL) are widely used for the stealth of underwater targets. In this paper, a measurement system based on the small water tank, for the frequency range of greater than 30 kHz, is developed and verified using reference targets. In order to design the water tank and the geometry of test samples, a program is developed to calculate the arrival time of interfering signals due to the reflection from water tank walls and also due to the diffraction from the edge of the test samples. Considering all the interfering signals, an optimal experimental configuration for water tank and test samples is designed and used throughout the experiment. Next, the signal processing algorithms to estimate ER and TL are developed based on the measured propagation loss reflecting the geometric spreading characteristics of the transducer. Finally, a set of reference targets such as aluminium plate and perfectly reflecting plate are used in a small water tank to verify the developed measurement system.
Time-Frequency Domain Impulsive Noise Detection System in Speech Signal
Choi, Min-Seok ; Shin, Ho-Seon ; Hwang, Young-Soo ; Kang, Hong-Goo ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 73~79
DOI : 10.7776/ASK.2011.30.2.073
This paper presents a new impulsive noise detection algorithm in speech signal. The proposed method employs the frequency domain characteristic of the impulsive noise to improve the detection accuracy while avoiding the false-alarm problem by the pitch of the speech signal. Furthermore, we proposed time-frequency domain impulsive noise detector that utilizes both the time and frequency domain parameters which minimizes the false-alarm problem by mutually complementing each other. As the result, the proposed time-frequency domain detector shows the best performance with 99.33 % of detection accuracy and 1.49 % of false-alarm rate.
Speaker Change Detection Based on a Graph-Partitioning Criterion
Seo, Jin-Soo ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 80~85
DOI : 10.7776/ASK.2011.30.2.080
Speaker change detection involves the identification of time indices of an audio stream, where the identity of the speaker changes. In this paper, we propose novel measures for the speaker change detection based on a graph-partitioning criterion over the pairwise distance matrix of feature-vector stream. Experiments on both synthetic and real-world data were performed and showed that the proposed approach yield promising results compared with the conventional statistical measures.
An Efficient ARQ for Multi-Hop Underwater Acoustic Channel with Long Propagation Delay and High Bit-Error Rate
Lee, Jae-Won ; Jang, Youn-Seon ; Cho, Ho-Shin ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 86~91
DOI : 10.7776/ASK.2011.30.2.086
In the underwater communications, the acoustic channel is in poor communication conditions, such as long propagation delay, narrow bandwidth, and high bit-error rate. For these bad acoustic channels, we propose an efficient automatic repeat request (ARQ) for multi-hop underwater network by using the concepts of concurrent bi-directional transmission, multiple sub-packets, and overhearing data packet instead of the acknowledgement signal. Our results show that the proposed ARQ significantly reduces the transmission latency especially in high BER compared with the existing Stop and Wait ARQ.
Floor Impact Noise Characteristics Depending on the Experimental Conditions Using Impact Ball
Lee, Won-Hak ; Haan, Chan-Hoon ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 92~99
DOI : 10.7776/ASK.2011.30.2.092
In Japan, bang machine has been considered to have problems about not only the impact force and frequency response which are different from the real impact sources such as children's jumping and running, but also damage in the wooden structure housing. Therefore, a new impactor for lower impact force to prevent demage in wooden structure housing was developed. The impact ball was adopted as the second standard impact source in JIS A 1418-2 and ISO 140-11. In the present study, floor impact sounds generated by impact ball with drop heights in four floors of mock-up building of Building Research Institute (BRI) similar to typical Japanese wooden structure housing were investigated and also compared to jumping sound. The results show that Impact ball sound dropped at 10 cm to 30 cm was most similar to jumping sound. And The impact sound levels at 250 and 500 Hz were more sensitive to drop height than other lower frequencies. The error that may occur from the difference of height of 10 cm up and down based on the standard drop height caused by the impact ball operated by human hands was approx. 1 dB or less only in its value of characteristic, but it must be carefully taken into Impact ball in the Korea Standard.
Music Genre Classification System Using Decorrelated Filter Bank
Lim, Shin-Cheol ; Jang, Sei-Jin ; Lee, Seok-Pil ; Kim, Moo-Young ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 100~106
DOI : 10.7776/ASK.2011.30.2.100
Music recordings have been digitalized such that huge size of music database is available to the public. Thus, the automatic classification system of music genres is required to effectively manage the growing music database. Mel-Frequency Cepstral Coefficient (MFCC) is a popular feature vector for genre classification. In this paper, the combined super-vector with Decorrelated Filter Bank (DFB) and Octave-based Spectral Contrast (OSC) using texture windows is processed by Support Vector Machine (SVM) for genre classification. Even with the lower order of the feature vector, the proposed super-vector produces 4.2 % improved classification accuracy compared with the conventional Marsyas system.
Development of Loop Filter Design of Plucked String Instruments
Cho, Sang-Jin ;
The Journal of the Acoustical Society of Korea, volume 30, issue 2, 2011, Pages 107~113
DOI : 10.7776/ASK.2011.30.2.107
This paper describes a development of a loop filter design in a physical modeling of the plucked string instrument. The conventional method proposed by V
ki cannot estimate right parameters if a sound has either very short sustain or no sustain. In order to overcome this drawback, we propose the use of the decay region and 5 to 20 harmonics of the sound in the estimation of loop filter parameters. The most appropriate filter coefficient is chosen by frequency signal to noise ratio. To verify the performance of the proposed method, the guitar, gayageum and geomungo were selected as the target because they have different shape, structure, and material of strings. Regardless of the duration of harmonics, the proposed method was able to estimate the loop filter parameters representing frequency-dependent damping of harmonics.