• MALSORI
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• no.46
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• pp.51-64
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• 2003

In order to produce high quality synthesized speech, it is very important to get an accurate grapheme-to-phoneme conversion and prosody model from texts using natural language processing. Robust preprocessing for non-Korean characters should also be required. In this paper, we analyzed Korean texts using a morphological analyzer, part-of-speech tagger and syntactic chunker. We present a new grapheme-to-phoneme conversion method for Korean using a hybrid method with a phonetic pattern dictionary and CCV (consonant vowel) LTS (letter to sound) rules, for unlimited vocabulary Korean TTS. We constructed a prosody model using a probabilistic method and decision tree-based method. The probabilistic method atone usually suffers from performance degradation due to inherent data sparseness problems. So we adopted tree-based error correction to overcome these training data limitations.

• Korean Journal of Cognitive Science
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• v.26 no.3
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• pp.323-355
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• 2015

This study examined grapheme-to-phoneme regularity effect among late Korean-English bilinguals by using whole word level task (lexical processing) and two meta-phonological tasks(sub-lexical processing): [1] English word naming task(whole word level), [2] rhyme judgement task(rhyme level), and [3] phoneme deletion task(phoneme level). Forty-three late Korean-English bilinguals participated in all three tasks. In these tasks, participants showed better performance in regular word conditions compared to irregular word conditions, demonstrating a clear English regularity effect. Post-hoc correlational analysis revealed strong correlation between word naming task and rhyme judgement task, which is different from the results reported with English monolinguals. The contradicting results might be due to the relevantly low English proficiency level among late Korean-English bilingual speakers. In conclusion, this study suggests that late Korean-English bilinguals make use of L2 grapheme-to-phoneme conversion (GPC) rule when reading L2 English words.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.499-511
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• 2016

The aim of this study was to find out effect of the orthographic representation on speech sound segmentation performance. Children's performances of the orthographic representation task and the speech sound segmentation task had positive correlation in words of phoneme-grapheme correspondence and negative correlation in words of phoneme-grapheme non-correspondence. In the case of words of phoneme-grapheme correspondence, there was no difference in performance ability between orthographic representation high level group and low level group, while in the case of words of phoneme-grapheme non-correspondence, the low level group's performance was significantly better than the high level group's. The most frequent errors of both groups were orthographic conversion errors and such errors were significantly more noticeable in the high level group. This study suggests that from the time of learning orthographic knowledge, children utilize orthographic knowledge for the performance of phonological awareness tasks.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.175-179
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• 2003

In order to produce a high quality (intelligibility and naturalness) synthesized speech, it is very important to get an accurate grapheme-to-phoneme conversion and prosody model. In this paper, we analyzed Chinese texts using a segmentation, POS tagging and unknown word recognition. We present a grapheme-to-phoneme conversion using a dictionary-based and rule-based method. We constructed a prosody model using a probabilistic method and a decision tree-based error correction method. According to the result from the above analysis, we can successfully select and concatenate exact synthesis unit of syllables from the Chinese Synthesis DB.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.87-90
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• 2003

In order to produce high quality synthesized speech, it is very important to get an accurate grapheme-to-phoneme conversion and prosody model from texts using natural language processing. Robust preprocessing for non-Korean characters should also be required. In this paper, we analyzed Korean texts using a morphological analyzer, part-of-speech tagger and syntactic chunker. We present a new grapheme-to-phoneme conversion method, i.e. a dictionary-based and rule-based hybrid method, for unlimited vocabulary Korean TTS. We constructed a prosody model using a probabilistic method and decision tree-based method.

• Proceedings of the KSPS conference
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• 2006.11a
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• pp.135-138
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• 2006

In this paper, we introduce a method for extracting grapheme-to-phoneme conversion rules from the transcription of speech synthesis database and a prosody modeling method using the light version of ToBI for a Korean conversational style TTS. We focused on representing the characteristics of the conversational speech style and the experimental results show that our proposed methods are suitable for developing a Korean conversional style TTS.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.387-394
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• 2004

In this paper, we propose a modified unsupervised linear alignment algorithm for building an aligned corpus. The original algorithm inserts null characters into both of two aligned strings (source string and target string), because the two strings are different from each other in length. This can cause some difficulties like the search space explosion for applications using the aligned corpus with null characters and no possibility of applying to several machine learning algorithms. To alleviate these difficulties, we modify the algorithm not to contain null characters in the aligned source strings. We have shown the usability of our approach by applying it to different areas such as Korean-English back-trans literation, English grapheme-phoneme conversion, and Korean morphological analysis.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.139-149
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• 2015

This paper aims to analyze pronunciation variations of loanwords produced by Korean and improve the performance of pronunciation modeling of loanwords in Korean by using syllable-based segmentation and phonological knowledge. The loanword text corpus used for our experiment consists of 14.5k words extracted from the frequently used words in set-top box, music, and point-of-interest (POI) domains. At first, pronunciations of loanwords in Korean are obtained by manual transcriptions, which are used as target pronunciations. The target pronunciations are compared with the standard pronunciation using confusion matrices for analysis of pronunciation variation patterns of loanwords. Based on the confusion matrices, three salient pronunciation variations of loanwords are identified such as tensification of fricative [s] and derounding of rounded vowel [ɥi] and [$w{\varepsilon}$]. In addition, a syllable-based segmentation method considering phonological knowledge is proposed for loanword pronunciation modeling. Performance of the baseline and the proposed method is measured using phone error rate (PER)/word error rate (WER) and F-score at various context spans. Experimental results show that the proposed method outperforms the baseline. We also observe that performance degrades when training and test sets come from different domains, which implies that loanword pronunciations are influenced by data domains. It is noteworthy that pronunciation modeling for loanwords is enhanced by reflecting phonological knowledge. The loanword pronunciation modeling in Korean proposed in this paper can be used for automatic speech recognition of application interface such as navigation systems and set-top boxes and for computer-assisted pronunciation training for Korean learners of English.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.370-372
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• 2001

본 논문은 ㄴ-첨가 규칙을 전 처리를 통한 문자열-발음열 변환 기법을 소개한다. 한국어 TTS 시스템에서의 고질적인 문제는 문자열-발음열 변환이라고 할 수 있는데, 그 이유는 한국어의 특징상 음운적 조건과 형태론적 조건등에 의해 다양한 방법과 예외처리를 요구하기 때문이다. 그 중 ㄴ-첨가 규칙은 위와 같은 대표적인 현상으로 많은 문제점과 그에 따른 연구를 필요로 하고 있다. 이 시스템은 형태소 분석을 선행한 후, 특수문자나 숫자를 정규화하고 ㄴ-첨가 규칙을 전 처리한 후, 음운변화 현상을 분석하여 선택적으로 규칙을 적용하여 발음열을 생성한다. 제안된 시스템은 기존의 시스템에 비해 더욱 효과적인 음운, 형태소 변화를 가져옴과 함께, 특히 ㄴ-첨가가 적용되는 문장을 효과적으로 해결할 수 있어 TTS시스템에 좋은 결과를 가져오게 될 것이다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.442-444
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• 2005

본 논문에서는 아라비안 숫자의 중의성을 효과적으로 제거하고 숫자 표현의 발음을 정확하게 문자화할 수 있는 임베디드 시스템용 경량화된 아라비안 숫자 읽기 시스템을 제안한다. 이를 위해 7 가지의 숫자 읽기 방식(Headings of Arabic Numerals RAN)을 분류하였고, 문자화 규칙을 설정하기 위해. (1) 문맥 자질, (2) 패턴 자질, (3) 휴리스틱 정보를 숫자 표현의 의미에 따라 분석하였다. 그리고 숫자의 문자화 시스템을 최적화하여 임베디드 시스템에 탑재하기 위해 (1) 형태소 분석 모듈의 분리, (2) 사전 압축, (3) 인명과 지명의 제거를 하였고, 이를 홍해 심각한 정확도 손실 없이 메모리 사용량과 처리 시간을 크게 줄일 수 있었다. 경량화된 mini-TAN 은 $96.9\~98.3\%$의 정확도를 보이며, 기존 상용 TTS 시스템에 비해서도 숫자 읽기의 처리에 있어 높은 정확도를 보인다.