• Title/Summary/Keyword: spectral tilts

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A study on the release burst spectra of the voiceless plosives from the English and Korean spontaneous speech corpus (영어와 한국어 자연발화 코퍼스에서의 무성 폐쇄음 개방 파열 스펙트럼 연구)

  • Hwang, Sunmi;Yoon, Kyuchul
    • Phonetics and Speech Sciences
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    • v.9 no.4
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    • pp.27-34
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    • 2017
  • The purpose of this work is to examine the English and Korean voiceless plosives from the Buckeye[15] and Seoul[16] corpus in terms of their static spectral characteristics. The plosives were automatically extracted by a Praat script. In order to estimate the percent correctness in the classification of the plosives, discriminant analyses were performed whose trainings were based on four spectral moments, i.e. the center of gravity, variance, skewness and kurtosis as suggested in [6]. Another set of discriminant analyses were performed based on the spectral tilts. In the last set of analyeses, the spectral moments and tilts were both used in the training. Results showed that the correct classification rate did not exceed around 65% in the best case, which suggested that phonetic cues other than the release burst would be necessary including the dynamic spectral aspects and vowel-onset cues.

A study on the voiceless plosives from the English and Korean spontaneous speech corpus (영어와 한국어 자연발화 음성 코퍼스에서의 무성 파열음 연구)

  • Yoon, Kyuchul
    • Phonetics and Speech Sciences
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    • v.11 no.4
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    • pp.45-53
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    • 2019
  • The purpose of this work was to examine the factors affecting the identities of the voiceless plosives, i.e. English [p, t, k] and Korean [ph, th, kh], from the spontaneous speech corpora. The factors were automatically extracted by a Praat script and the percent correctness of the discriminant analyses was incrementally assessed by increasing the number of factors used in predicting the identities of the plosives. The factors included the spectral moments and tilts of the plosive release bursts, the post-burst aspirations and the vowel onsets, the durations such as the closure durations and the voice onset times (VOTs), the locations within words and utterances and the identities of the following vowels. The results showed that as the number of factors increased up to five, so did the percent correctness of the analyses, resulting in 74.6% for English and 66.4% for Korean. However, the optimal number of factors for the maximum percent correctness was four, i.e. the spectral moments and tilts of the release bursts and the following vowels, the closure durations and the VOTs. This suggests that the identities of the voiceless plosives are mostly determined by their internal and vowel onset cues.

Meso-tetrakis(N-methylpyridinium-4-yl)porphyrin at the Minor Groove of Contiguous Adenine-Thymine Base Pairs

  • Chae, Youn-Hee;Jin, Biao;Kim, Jong-Ki;Han, Sung-Wook;Kim, Seog-K.;Lee, Hyun-Mee
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2203-2208
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    • 2007
  • Three possible binding modes of cationic meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) to d[(GCATATATGC)2] duplex were investigated by the molecular dynamics (MD) simulation. Among the three binding modes namely, “along the groove”, “across the groove” and “face on the groove”, the “across the groove” model exhibited the largest negative binding free energy and the DNA backbone remained as the B form. In this model, the molecular plain of the TMPyP tilts 45o with respect to the DNA helix axis and is largely exposed to the solvent. TMPyP was stabilized mainly by the interaction between the positively charged neighboring pyridinium moieties of TMPyP and negatively charged phosphate groups of DNA. The result obtained in this work by MD and the report (Jin, B. et al., J. Am. Chem. Soc. 2005, 127, 2417.) that the spectral properties of poly[d(A-T)2] bound TMPyP in the presence and absence of the minor groove binding drug 4',6- diamidino-2-phenylindole are similar, we propose that TMPyP bind across the minor groove of the AT rich- DNA.