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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 13, Issue 6 - Dec 1994
Volume 13, Issue 5 - Oct 1994
Volume 13, Issue 4 - Aug 1994
Volume 13, Issue 3 - Jun 1994
Volume 13, Issue 2 - Apr 1994
Volume 13, Issue 1 - Feb 1994
Volume 13, Issue 2E - 00 1994
Volume 13, Issue 1E - 00 1994
Selecting the target year
Propagation Loss Measurement of Underwater Sound Wave using Narrow Band Acoustic Signal
Na, Young-Nam ; Shim, Tae-Bo ; Choi, Jin-Hyeok ; Chang, Duck-Hong ; Kim, Seong-Il ; Han, Jeong-Woo ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 5~15
In order to examine the propagation loss associated with water depth and bottom sediment type, an acoustic experiment was conducted in the Southeast Sea of Korea. A sound source was towed along the pre-defined tracks in about 5kts and the signal was simultaneously received at three bottom-moored hydrophones. The propagation loss of sound wave traveling along the isodepth was compared with that crossing the isodepth. The former case shows, in general, less loss than the latter. This trend is stronger as the distance between a source and a receiver increases. When sound wave propagates across the isodepth, we also find that the propagation loss is influenced by the upsloping and downslopoing conditions of wave propagtion. In general, the propagation loss under downsloping condition is smaller than that of upsloping condition, and the differences are as large as 10dB in some cases. However, little difference are found in the propagation loss depending on the bottom types : gravelly sand and sand-silt-clay. Meanwhile, the optimum propagation frequencies are found within range of 130-255Hz.
A Single Channel Adaptive Noise Cancellation for Speech Signals
Gahng, Hae-Dong ; Bae, Keun-Sung ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 16~24
A single channel adaptive noise canceling (ANC) technique is presented for removing effects of additive noise on the speech signal. The conventional method obtains a reference signal using the pitch estimated on a frame basis from the input speech. The proposed method, however, gets the reference signal using the delay estimated recursively on a sample by sample basis. To estimate the delay, we derive recursion formula of autocorrelation function and average magnitude difference function. The performance of the proposed method is evaluated for the speech signals distorted by the additive white Gaussian noise. Experimental results with normalized least mean square (NLMS) adaptive algorithm demonstrate that the proposed method improves the perceived speech quality quite well besides the signal-to-noise ratio.
Korean Digit Recognition Under Noise Environment Using Spectral Mapping Training
Lee, Ki-Young ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 25~32
This paper presents the Korean digit recognition method under noise environment using the spectral mapping training based on static supervised adaptation algorithm. In the presented recognition method, as a result of spectral mapping from one space of noisy speech spectrum to another space of speech spectrum without noise, spectral distortion of noisy speech is improved, and the recognition rate is higher than that of the conventional method using VQ (vector quatization) and DTW(dynamic time warping) without noise processing, and even when SNR level is 0dB, the recognition rate is 10 times of that using the conventional method. It has been confirmed that the spectral mapping training has an ability to improve the recognition performance for speech in noise environment.
On A Reduction of Pitch Searching Time by Preprocessing in the CELP Vocoder
Kim, Dae-Sik ; Bae, Myeong-Jin ; Kim, Jong-Jae ; Byun, Kyung-Jin ; Han, Ki-Chun ; Yoo, Hah-Young ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 33~40
Code Excited Linear Prediction(CELP) speech coders exhibit good performance at data rates below 4.8 kbps. This major drawback of CELP type coders is required much computation. In this paper, we propose a new pitch search method that preserves the quality of the CELP vocoder with reducing complexity. In the pitch searching, we detect the segments of high correlation by a simple preprocessing, and then carry out the pitch searching only for the segments obtained by the preprocessing. By using the proposed method, we can get approximately
complexity reduction in the pitch search.
Numerical analysis for nearfield measurement error in a three-dimensional intensity probe.
Kim, Suk-Jae ; Jee, Suk-Kun ; Suzuki, Hideo ; Kim, Chun-Duck ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 41~50
We studied an inherent error be caused by a measuring acoustic intensity using probe which can measure simultaneously the three-dimensional acoustic intensity. This three-dimensional intensity probe was constructed with four microphones, proposed by Suzuki et al. . In the computer simulation, we analyzed the nearfield measurement error with arbitary direction and each of axis direction on the ideal point source and the plate sound source which have finite size. From the results, in case of point source, we obtained accurate measurement below about 1dB when the distance of measurement was about 2.5 times with the distance among microphones in this probe. And in the case of plate sound source, the nearfield measurement error was decreased as the length of one side became above 0.02m, we obtained accurate measurement below about 1dB when the length of one side is 0.2m. The nearfield measurement error of finite size sound is small to ignore. Therefore this probe is useful to measure nearfield intensity.
Consonant/Vowel Segmentation in Monosyllabic Speech Data Using the Fractal Dimension
Choi, Chul-Young ; Kim, Hyung-Soon ; Kim, Jae-Ho ; Son, Kyung-Sik ; , ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 51~62
In this paper, we performed a class of experiments on segmenting consonant and vowel from Korean consonant-vowel (CV) monosyllable data, using the fractal dimension of the speech signals. We chose the Minkowski-Bouligand dimension as the fractal dimension, and computed it using the morphological covering method. In order to examine the usefulness of the fractal dimension in speech segmentation we carried out speech segmentation experiments using the fractal dimension alone, using the short-time energy alone, and using both the fractal dimension and the short-time energy, and compared the results. From the experiments, segmentation accuracy of
was achieved for the case with using the multiplication of the slope of the fractal dimension and that of the energy, while the segmentation accuracies for the cases with using the slope of either the fractal dimension or energy alone were slightly lower
or much lower
than the above case, respectively. These results indicate that the fractal dimension can be used as a good parameter for speech segmentation.
A Codeword Tying Algorithm in Speech Recognition based on Discrete Hidden Markov Model
Kim, Do-Yeong ; Kim, Nam-Soo ; Un, Chong-Kwan ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 63~70
In this Paper, we propose a new codeword tying algorithm based on a tree structured classfier. The proposed algorithm which can be viewed as a kind of soft decision using statistical properties between codewords and states has an advantage of fast construction, and guarantees a unique optimal solution. Also, it can easily be applied to any speech recognition system based on discrete hidden Markov model (HMM). Experimental results on speaker-independent isolated word recognition show error reduction of
for the codebook of size 256 and
for 512 size and also HMM parameter reduction of about
Acoustic radiation from a line array of bubbles in water
Choi, Bok-Kyeoung ; Yoon, Suk-Wang ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 71~77
The frequency characteristics of sound radiated by a line array of bubbles in water was investigated theoretically and experimentally. In the theory we proposed an effective coupled harmonic oscillator model for a line array of bubbles treating the interaction of only adjacent bubbles as the coupling of classical harmonic oscillators. For weak coupling of bubbles that the distance between adjacent bubbles is larger than the diameter of a bubble, the pressented theoretical model shows very good agreement with the experimental results.
Technical standards on magnetic field strength for a hearing-aid-compatible telephone
Kang, Kyeong-Ok ; Kang, Seong-Hoon ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 78~84
휴먼인터페이스와 음향정보처리 기술
Hong, Jin-Woo ; Kang, Seong-Hoon ;
The Journal of the Acoustical Society of Korea, volume 13, issue 3, 1994, Pages 85~91