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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of the Acoustical Society of Korea
Journal Basic Information
Journal DOI :
The Acoustical Society of Korea
Editor in Chief :
Volume & Issues
Volume 14, Issue 6 - Dec 1995
Volume 14, Issue 5 - Oct 1995
Volume 14, Issue 4 - Aug 1995
Volume 14, Issue 3 - Jun 1995
Volume 14, Issue 2 - Apr 1995
Volume 14, Issue 1 - Feb 1995
Volume 14, Issue 2E - 00 1995
Volume 14, Issue 1E - 00 1995
Selecting the target year
The Image Compression Using the Central Vectors of Clusters
Cho, Che-Hwang ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 5~12
In the case where the set of training vectors constitute clusters, the codevectors of the codebook which is used to compression for speech and images in the vector quantization are regarded as the central vectors of the clusters constituted by given training vectors. In this work, we consider the distribution of Euclidean distance obtaining in the process of searching for the minimum distance between vectors, and propose the method searching for the proper number of and the central vectors of clusters. And then, the proposed method shows more than the about 4[dB] SNR than the LBG algorithm and the competitive learning algorithm
A Study on an Image Classifier using Multi-Neural Networks
Park, Soo-Bong ; Park, Jong-An ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 13~21
In this paper, we improve an image classifier algorithm based on neural network learning. It consists of two steps. The first is input pattern generation and the second, the global neural network implementation using an improved back-propagation algorithm. The feature vector for pattern recognition consists of the codebook data obtained from self-organization feature map learning. It decreases the input neuron number as well as the computational cost. The global neural network algorithm which is used in classifier inserts a control part and an address memory part to the back-propagation algorithm to control weights and unit-offsets. The simulation results show that it does not fall into the local minima and can implement easily the large-scale neural network. And it decreases largely the learning time.
Convergence Behavior of the Least Mean Fourth Algorithm for a Multiple Sinusoidal Input
Lee, Kang-Seung ; Lee, Jae-Chon ; Youn, Dae-Hee ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 22~30
In this Paper we study the convergence behavior of the least mean fourth (LMF) algorithm where the error raised to the power of four is minimized for a multiple sinusoidal input and Gaussian measurement noise. Here we newly obtain the convergence equation for the sum of the mean of the squared weight errors, which indicates that the transient behavior can differ depending on the relative sizes of the Gaussian noise and the convergence constant. It should be noted that no similar results can be expected from the previous analysis by Walach and Widrow.
Speech Recognition on Korean Monosyllable using Phoneme Discriminant Filters
Hur, Sung-Phil ; Chung, Hyun-Yeol ; Kim, Kyung-Tae ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 31~39
In this paper, we have constructed phoneme discriminant filters [PDF] according to the linear discriminant function. These discriminant filters do not follow the heuristic rules by the experts but the mathematical methods in iterative learning. Proposed system. is based on the piecewise linear classifier and error correction learning method. The segmentation of speech and the classification of phoneme are carried out simutaneously by the PDF. Because each of them operates independently, some speech intervals may have multiple outputs. Therefore, we introduce the unified coefficients by the output unification process. But sometimes the output has a region which shows no response, or insensitive. So we propose time windows and median filters to remove such problems. We have trained this system with the 549 monosyllables uttered 3 times by 3 male speakers. After we detect the endpoint of speech signal using threshold value and zero crossing rate, the vowels and consonants are separated by the PDF, and then selected phoneme passes through the following PDF. Finally this system unifies the outputs for competitive region or insensitive area using time window and median filter.
PDOCM : Fast Text Compression on MasPar Machine
Min, Yong-Sik ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 40~47
Due to rapid progress in data communications, we are able to acquire the information we need with ease. One means of achieving this is a parallel machine such as the MasPar. Although the parallel machine makes it possible to receive/transmit enormous quantities of data, because of the increasing volume of information that must be processed, it is necessary to transmit only a minimal amount of data bits. This paper suggests a new coding method for the parallel machine, which compresses the data by reducing redundancy. Parallel Dynamic Octal Compact Mapping (PDOCM) compresses at least 1 byte per word, compared with other coding techniques, and achieves a 54.188-fold speedup with 64 processors to transmit 10 million characters.
Capacity Evaluation of a Digital Cellular CDMA System for Reverse Link
Park, Yong-Seo ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 48~55
The capacity of a digital cellular CDMA system is evaluated by computer simulation for reverse link (mobile-to-base) with 37 hexagonal cells including 3 rings from a center cell. It is assumed that the channels have shadow fading and the system is ideally power controlled. In this paper the capacity of CBMA system is evaluated for various propagation exponents, voice activity factors and neighboring cell traffics. The following results are obtained. The capacity of CDMA system is increased according to the increase of the propagation exponents and the decrease of the voice activity factors. Its capacity is about 15 and 5 times larger thari that of analog cellular FM/FDMA and digital cellular TDMA for
respectively, and is very sensitive to the neighboring cell traffics.
Control Rules of Synthetical Pauses and Syllable Duration depending on Pronunciation Speed in Korean Speech
Kim, Jae-In ; Kim, Jin-Young ; Lee, Tae-Won ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 56~64
In this paper we extracted control rules of synthetical pauses and syllable durations depending on pronunciation speed in Korean speech from the spoken sentences recorded by 18 professional announcers. Pause rules were divided into three categories : pause between sentences(PBS), pause between clauses(PBC) and pause between intonational phrases(PBI). From the analysis results it is found that comparing the slowly spoken sentence with the fast spoken sentence the duration difference between them is due to the synthetical pause increments, expecially, of PBS and PBC. In addition, it is also found that the increment ratio of the mean syllable duration Is low. On the other hand, PBI was not pronounced in the fast spoken sentences. PBI was pronounced at the pronunciation speed(PS) over some PS.
A Study on the Acoutical Characteristics of Last Consonants in Korean
Kim, Seon-Il ; Hong, Ki-Won ; Lee, Haing-Sei ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 65~72
An auditory experiments for the phonetic value of the last consonants when its signal is transmitted through the amplifier from the last to the first, shortly speaking, time reversed waveform, were done for the 14 Korean consonants. Then the last consonant becomes to the first consonant in the time reversed waveform. The listeners who heard the 14 reversed consonants have recorded the phonetic value being heard. We analyzed these results by the method of articulation and the position of articulation. By the results, the phonetic value of the last consonants /n/, /l/ and /m/ is the same as the first consonants. Last consonant /d/ is heard like first consonant /n/. Last consonant /ng/ is heard like first consonant /m/. Last consonants /k/ and /b/ don't have any particular phonetic values. These results were tested by the experiments and were analyzed by the principle of articulation.
Material Noise Reduction in Ultrasonic Test Using Polarity Thresholding Algorithm
Koo, Kil-Mo ; Ko, Dae-Sik ; Kim, Tae-Hyoun ; Jun, Kye-Suk ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 73~80
In this paper, Polarity Thresholding(PT) algorithm has been studied to enhance the received signal in ultrasonic inspection of the stainless-steel(SUS 304) which is the primary piping material of a nuclear power plant. The spectral decomposition components obtained by splitting the spectrum of received signals are composed of dispersive signal of the interference pattern produced by the grain boundaries and nondispersive signal by the flaw. PT algorithm enhance the SNR of received signal by using above properties. In experiment the stainless-steel has been chosen as the sample and heat-treated at 1125, 1150, 1175, and
, respectively. And the flat-bottom hole type defects have been made artificially in samples. The pulse-echo signals from the sample by using ultrasonic transducer of center frequency 5 MHz have been processed by PT algorithm. It has been shown that PT algorithm enhanced the SNR by average 14.2 dB.
Korean Continuous Speech Recognition Using Discrete Duration Control Continuous HMM
Lee, Jong-Jin ; Kim, Soo-Hoon ; Hur, Kang-In ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 81~89
In this paper, we report the continuous speech recognition system using the continuous HMM with discrete duration control and the regression coefficients. Also, we do recognition experiment using One Pass DP method(for 25 sentences of robot control commands) with finite state automata context control. In the experiment for 4 connected spoken digits, the recognition rates are
when the discrete duration control and the regression coefficients are included, and
when they are not included. In the experiment for 25 sentences of the robot control commands, the recognition rate are
when FSN is not included and
when FSN is included.
Design and Implementation of a Hypermedia System for Hypermedia Presentation
Park, Jong-Hoon ; Choi, Ki-Ho ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 90~107
In this paper, we propose the time relation model among the media with the concept of time and space on hypermedia system. This model classifies time proceeding relations in the node and among media connected with the link which is extended to internal link (while a current node remains, a destination node of internal link proceeds) and external link(a current node is replaced by a destination node of external link). Using this model, hypermedia system for hypermedia presentation is designed and implemented. This hypermedia system provides editing tools and controllers to created and edit nodes with time relation information, link tool to construct associative relations among nodes and navigation tool to control context flows.
An Acoustic Analysis of Mufflers with a Concentric Extended Pipe
Lee, Jun-Shin ; Lee, Jeong-Guon ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 108~114
Cylindrical chamber mufflers with an extended inlet or outlet are extensively used in many application fields to reduce the propagated noise in ducts. The basic attenuation effectivencess in the low frequency region can be explained by the reactive wave action inside the expansion chamber associated with the geometric configurations of the inlet and outlet locations, and the area expansion of the jacket. In this study, an acoustic analysis is carried out for a concentric extended pipe inserted into a simple expansion chamber. An algebraic equation is derived by using the eigenfuction expansion and orthogonality principle in which the acoustic pressures and particle velocities defined on each subdivided surface are expressed by the separable coordinates. By using the proposed analytical method, transmission losses are predicted for several configurations of the concentric extended systems and they agree very well with experimental results.
A Space-Tapering Approach for a Rectangular Array
Chang, Byong-Kun ;
The Journal of the Acoustical Society of Korea, volume 14, issue 1, 1995, Pages 115~122
It is practical to taper the element (e.g., antenna or sensor) spacing with uniform weight rather than to taper the weights with uniform spacing. In a rectangular array, a triangular grid geometry of elements is more economical than a rectangular grid geometry in terms of reducing the number of elements. A space-tapering approach is proposed to improve the performance of a rectangular phased array with a triangular grid geometry of elements above a ground plane. The effects of space tapering on the main beam width and sidelobe level are discussed. It is shown that the proposed approach improves the sidelobe performance while the main beam width becomes a little broader.