• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.45-48
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• 2003

In general, speech coding methods are classified into the following three categories: the waveform coding, the source coding and the hybrid coding. Fast speaking is possible to encode with a few information compared with slow speaking rate. In case of speaking rate, low frequency band is more important than high frequency band while listening. Speech vocoding technique is developing to way with low bit rate and complexity and high sound quality. the CELP type of vocoder support very good sound quality with low bit rate but these vocoders don't consider about the speaking rate. When we consider speaking rate and encode the frame depending on the speaking rate, the bit rate is able to reduce the bit rate than the conventional vocoder. We propose the technique to estimate the speaking rate and applied PSOLA technique in case of the frame of slow speaking rate. As a result of simulation bit rate can be reduced about 300 bps.

• 한국콘텐츠학회논문지
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• 제11권3호
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• pp.318-326
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• 2011

노인인구 증가와 함께 신경학적 결함을 가진 장 노년기 성인들이 증가하면서 신경 말 언어장애 성인들 의 재활을 위하여 구어 유창성에 대한 기초연구가 필요하다. 그래서 본 연구에서는 신경언어장애가 없는 50대에서 70대 정상 성인을 대상으로 언어표본을 수집하여 연령 및 성별로 구어 유창성의 특성을 비교 분석하였다. 50대, 60대, 70대 각 연령대별 30명(남15명, 여15명)씩 총 90명의 언어 표본을 수집하여 구어 속도, 비유창성 빈도 등을 비교한 결과, 첫째, 70대 성인의 구어 속도가 50대 및 60대 성인의 구어 속도보다 느렸다. 그리고 50대, 60대 및 70대 모두 성별 간 구어 속도에서 차이가 없었다. 둘째, 50대, 60대 및 70대 성인들 간 정상적 비유창성 및 전체 비유창성의 빈도에서 차이가 없었다. 각 연령대별 성별 간에도 차이가 없었다. 셋째, 모든 연령대 성인들의 구어 속도와 비유창성 빈도와 상관이 없었다.

• 말소리와 음성과학
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• 제15권4호
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• pp.1-10
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• 2023

본 연구에서는 AI Hub에 구축된 '교육용 한국인의 영어 음성 데이터'에 있는 발음 평가 데이터를 활용하여 철자 기반 발화 속도 및 조음 속도와 음절 기반 발화 속도 및 조음 속도 중 발음 정확성 및 운율 유창성, 합산 점수를 예측하는 모델에 어떤 요소가 더 유의미한 영향을 미치는지 분석하였다. 이를 위해 13세, 19세, 26세 연령별, 성별, 수준별로 이 코퍼스의 훈련 데이터에서 총 900개 발화를 추출하여 데이터에 포함된 다양한 요소를 활용해 평가 점수를 예측하는 선형효과분석을 실행하였다. 선형효과분석에서 최적의 세 개 모델을 통해 예측된 평가 점수를 검증 데이터에서 추출한 총 180개 발화의 평가 점수와 얼마나 상관관계가 있는지도 분석하였다. 분석 결과 발음의 정확성과 운율의 유창성, 합산 점수 예측 모델 모두 철자 기반 발화 속도와 조음 속도보다 음절 기반 발화 속도와 조음 속도가 평가 점수를 예측하는데 더 큰 영향을 주는 것으로 밝혀졌다. 모델에서 예측한 점수와 검정 데이터의 실제 점수와의 상관계수는 .65에서 .68 사이로 각 모델의 평가 점수 예측력이 나쁘지 않았다. 발화 속도와 조음 속도 간에 어떤 요소가 더 큰 영향을 미치는지는 본 연구를 통해 밝혀내지 못하였다.

• 전자공학회논문지B
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• 제31B권1호
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• pp.11-22
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• 1994

For the conventional systme based on word, it is very difficult to enlarge the number of vocabulary. To cope with this problem, we must use more fundamental units of speech. For example, syllables and phonemes are such units, Korean speech consists of initial consonants, middle vowels and final consonants and has characteristic that we can obtain syllables from speech easily. In this paper, we show a speech recognition system with the advantage of the syllable characteristics peculiar to the Korean speech. The algorithm of recognition system is the Time Delay Neural Network. To recognize many recognition units, system consists of initial consonants, middle vowels, and final consonants recognition neural network. At first, our system recognizes initial consonants, middle vowels and final consonants. Then using this results, system recognizes isolated words. Through experiments, we got 85.12% recognition rate for 2735 data of initial consonants, 86.95% recognition rate for 3110 data of middle vowels, and 90.58% recognition rate for 1615 data of final consonants. And we got 71.2% recognition rate for 250 data of isolated words.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.277-280
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• 2001

The preprocessing is very important course in speech signal processing. It influence the compression-rate in speech coding and the recognition-rate in speech recognition etc. In this paper, we propose that minimizing window-influence method with pitch period and start points. The proposed method is available for voiced detection and word labeling.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.203-206
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• 2002

In this paper, we present a sentence speech recognizer for twenty questions game. The proposed approaches for speaker-independent sentence speech recognition can be divided into two steps. One is extraction of the number of syllables in eojeol for candidate reduction, and the other is knowledge based language model for sentence recognition. For twenty questions game, we implemented speech recognizer using 956 sentences and 1095 eojeols. The results obtained in our experiments were 87% sentence recognition rate and 90.15% eojeol recognition rate.

• 한국멀티미디어학회논문지
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• 제10권12호
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• pp.1551-1558
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• 2007

The standard of evaluating function of speech coder for mobile telecommunication can be shown in channel capacity, noise immunity, encryption, complexity and encoding delay largely. This study is an algorithm to reduce complexity applying to CDMA(Code Division Multiple Access) mobile telecommunication system, which has a benefit of keeping the existing advantage of telecommunication quality and low transmission rate. This paper has an objective to reduce the computing complexity by controlling the frequency band nonuniform during the changing process of LSP(Line Spectrum Pairs) parameters from LPC(Line Predictive Coding) coefficients used for EVRC(Enhanced Variable-Rate Coder, IS-127) speech coders. Its experimental result showed that when comparing the speech coder applied by the proposed algorithm with the existing EVRC speech coder, it's decreased by 45% at average. Also, the values of LSP parameters, Synthetic speech signal and Spectrogram test result were obtained same as the existing method.

• 말소리와 음성과학
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• 제9권2호
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• pp.77-83
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• 2017

We propose a new method to reduce emotion recognition errors caused by variation in speaker characteristics and speech rate. Firstly, for reducing variation in speaker characteristics, we adjust features from a test speaker to fit the distribution of all training data by using the histogram equalization (HE) algorithm. Secondly, for dealing with variation in speech rate, we augment the training data with speech generated in various speech rates. In computer experiments using EMO-DB, KRN-DB and eNTERFACE-DB, the proposed method is shown to improve weighted accuracy relatively by 34.7%, 23.7% and 28.1%, respectively.

• 대한음성학회지:말소리
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• 제55권
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• pp.143-158
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• 2005

The adequate compression algorithm is essential to achieve high quality embedded TTS system. in this paper, we Propose waveform interpolation coder for TTS corpus compression after many speech coder investigation. Unlike speech coders in communication system, compression rate and anality are more important factors in TTS DB compression than other performance criteria. Thus we select waveform interpolation algorithm because it provides good speech quality under high compression rate at the cost of complexity. The implemented coder has bit rate 6kbps with quality degradation 0.47. The performance indicates that the waveform interpolation is adequate for TTS DB compression with some further study.

• 음성과학
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• 제6권
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• pp.181-195
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• 1999

This study proposes a method of recognizing postpositions and suffixes in Korean spoken language, using prosodic information. We detect grammatical boundaries automatically at first, by using prosodic information of the accentual phrase, and then we recognize grammatical function words by backward-tracking from the boundaries. The experiment employs 300 sentential speech data of 10 men's and 5 women's voice spoken in standard Korean, in which 1080 accentual phrases and 11 postpositions and suffixes are included. The result shows the recognition rate of postpositions in two cases. In one case in which only correctly detected boundaries are included, the recognition rate is 97.5%, and in the other case in which all detected boundaries are included, the recognition rate is 74.8%.