• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.23 no.1
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• pp.33-42
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• 2012

Background and Objectives : Dysarthria refers to speech disorder that causes difficulties in speech communication due to paralysis, muscle weakening, and incoordination of speech muscle mechanism caused by damaged central or peripheral nerve system. Pitch, strength and speed are influenced by dysarthria during detonation due to difficulties in muscle control. As evaluation items, alternate motion rate and diadochokinesis have been commonly used, and articulation is also an important evaluation items. The purpose of this study is to find acoustic characteristics on sound production of dysarthria patients. Materials and Methods : Research subjects have been selected as 20 dysarthria patients and 20 subjects for control group, and voice sample was composed of bilabial, alveolar sound, and velar sound in diadochokinetic rate, while consonant articulation test was composed of bilabial plosive, alveolar plosive, velar plosive. Analysis items were composed of 1) speaking rate, energy, articulation time of diadochokinesis, 2) voice onset time (VOT), total duration (TD), vowel duration (VD), hold of plosives. Results and Conclusions : The number of diadochokinetic rate of dysarthria was smaller than control group. Both control group and dysarthria group was highly presented in the order of /t/>/p/>/k/. Minimum energy range per cycle during diadochokinetic rate of dysarthria group was smaller than control group, and presented statistical significance in /p/, /k/, /ptk/. Maximum energy range was larger than control group, and presented statistical significance in /t/, /ptk/. Articulation time, gap, total articulation time during diadochokinetic rate of dysarthria group was longer than control group and presented statistical significance. The articulation time was presented in both control group and dysarthria group in the order of /k/>/t/>/p/, while Gap was presented in the order of /p/>/t/>/k/ for control group and /p/>/k/>/t/ for dysarthria group. VOT, TD, VD regarding plosives of dysarthria group were longer than control group. Hold showed large deviation compared to control group that had appeared due to declined larynx and articulation organ motility.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.20-24
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• 1988

This paper proposed the phonemic segmentation method that employed two types of Likelihood Ratio that measures the change of spectral structure. By this method, isolated digits and words of VCV form are segmented into phoneme-unit and especially, first-burst part in an aspirated bilabial plosive is divided.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.482-489
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• 2014

The purposes of this study are (1) to see if the length of residence in Korea affects to the VOT values of Korean plosives produced by Chinese speakers (2) to investigate if such VOT values are different in non-sense words and real words and (3) to find out how such VOT values are related to the native Korean speakers' understanding of the words. For these purposes, eighteen Chinese speakers' VOT values of Korean plosives were measured using Speech Analyzer and their pronunciations were evaluated by three native Korean speakers. The results show that there is no effect of both (1) length of residence in Korea and (2) production of non-sensed words and sensed words. In addition, it is noticed that VOT values of some plosives affect more to the native Korean speakers' understanding of the words, while some are not.

• MALSORI
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• no.47
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• pp.31-49
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• 2003

This paper investigates phonation types of Malay plosives and compares Malay plosives with Korean ones in terms of VOT, F0, duration of closure, and durations of the preceding and following vowels. This study is significant in that it specifies phonetic characteristics of phonation types of the two languages and provides phonetic bases for teaching and learning either of the two languages. The results showed that Malay voiceless plosives are greater than voiced ones in VOT, F0, duration of closure, but the other way in durations of the preceding and following vowels. Comparison of the two languages, particularly in terms of the distribution of VOT, indicates that Malay voiceless plosives are close to Korean fortis plosives.

• The Journal of the Korean dental association
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• v.10 no.9
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• pp.605-625
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• 1972

한글의 파열자음(Plosive Consonants of stop consonants)인 ㄱ, R, ㅋ, ㅃ, ㅍ이나, ㄷ, ㄸ, ㅌ의 삼중 구별은 외국어에서는 찾아 볼수 없는 한글 고유의 특성이라고 생각되어 왔다. 이는 한국인 학자에게 뿐만 아니라 외국인 학자에게도 크나큰 관심사가 되어 왔다. 그 가장 큰 이유중의 하나가 소위 파열자음의 생리기전면에서 볼때, p,b나 k,g의 구별이 단순히 무성(Voiceless)대 유성(Voiced)의 차이냐 또는 근육의 힘의 차이냐 하는 문제가 오랫동안 국제학계에서 논난의 대상이 되어왔기 때문이다. 둘째로는 기이하게도 한글의 파열자음은 모두 무성자음으로 외국어에서 볼수있는 유성대 무성의 대조는 없으며, 다만 근육의 gal의 대조가 있지 않을까 생각되어 왔기 때문이다. 그러나 현재까지는 이 세가지 종류의 한글파열자음 발음시의 생리기전의 차이를 규명한 연구가 없었다. 저자는 이점에 착안하여 미국 위스컨신대학교 언어병리학 및 생리학 실험실에서 고도로 발달된 최신 연구기구를 이용하여 한글파열 자음 발음시의 생리기전의 차이를 규명하였다. 서론 연구방법, 연구결과, 결론에 관한 자세한 내용은 영문초록에 기술되어 있다.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.481-485
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• 1989

The object of this parer is on the design of an broad board classifier for connected. Korean digit. Many approaches have been applied in speech recognition systems: parametric vector quantization, dynamic programming and hiden Markov model. In the 80's the neural network method, which is expected to solve complex speech recognition problems, came bach. We have chosen the rule based system for our model. The phoneme-groups that we wish to classify are vowel_like, plosive_like fricative_like, and stop_like.The data used are 1380 connected digits spoken by three untrained male speakers. We have seen 91.5% classification rate.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.179-184
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• 2005

The aim of this paper is to analyze the phonetic features of the lexical contrastive focus and the segmental contrastive focus. In this paper, I made two variables to study the realization of the contrastive focus. One is the three phonation types of the Korean plosive, a lenis, a fortis and an aspirate. The other is the positions of the segmental contrastive focus syllable in a word. I examined pitch, duration, intensity, VOT, formant, and so on. The realization of focus is different by the phonation types and the positions of the focused syllable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.234-239
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• 2008

For the efficient coding and transmission, the speech signal can be classified into three distinctive classes: voiced, unvoiced, and transition classes. At low bit rate coding below 4 kbit/s, conventional sinusoidal transform coders synthesize speech of high quality for the purely voiced and unvoiced classes, whereas not for the transition class. The transition class including plosive sound and abrupt voiced-onset has the lack of periodicity, thus it is often classified and synthesized as the unvoiced class. In this paper, the efficient algorithm for the transition class detection is proposed, which demonstrates superior detection performance not only for clean speech but for noisy speech. For the detected transition frame, phase information is transmitted instead of magnitude information for speech synthesis. From the listening test, it was shown that the proposed algorithm produces better speech quality than the conventional one.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.4
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• pp.33-41
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• 1997

Korean unvoiced phonemes consist of nonstationary parts comparing that the vowels and nasal consonants consist of quasi-stationary part. And some phonemes, which have smae point of articulation but differnt manner of articulation, has similar characteristics, so it makes to be hard to distinguish each other. A new method usin gchanges and characteristics of acoustic properties of these phonemes to improve recognition rate are proposed. And because these changes and cahracteristics evidently occur in continuous speech except some unvoiced consonants are articulated as voiced phoneme in case to be used as an midial between voiced phonemes, this method can be applied easily. The features of the frames extracted to represent each phonemes are used asinputs to the hierarchical neural network. And with these results final decision for phoneme recognition is made thorugh post processing which the new method is applied to. Through the experimental recognition results for 9 unvoiced consonants which belong to bilabial, alveolar, and velar phoneme series, 89.4% recognition rate to distinguish in same phoneme series is obtained, and 85.6% recognition rate is obtained in case of including cistinguishing phoneme series.

• Journal of the Ergonomics Society of Korea
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• v.10 no.1
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• pp.3-10
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• 1991

The teach pendant and keyboard have been used as an input device of control command in human-robot sustem. But, many problems occur in case that the usef is a novice. So, speech recognition system is required to communicate between a human and the robot. In this study, Korean voice commands, eitht robot commands, and ten digits based on the broad phonetic analysis are described. Applying broad phonetic analysis, phonemes of voice commands are divided into phoneme groups, such as plosive, fricative, affricative, nasal, and glide sound, having similar features. And then, the feature parameters and their ranges to detect phoneme groups are found by minimax method. Classification rules are consisted of combination of the feature parameters, such as zero corssing rate(ZCR), log engery(LE), up and down(UD), formant frequency, and their ranges. Voice commands were recognized by the classification rules. The recognition rate was over 90 percent in this experiment. Also, this experiment showed that the recognition rate about digits was better than that about robot commands.