• Proceedings of the KSLP Conference
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• 1997.11a
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• pp.253-253
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• 1997

비폐색이 있는 경우 음성이 변하는 것을 쉽게 느낄 수 있지만, 비폐색 때의 음향학적인 특성에 대하여 알려진 바를 찾기는 쉽지 않다. 저자들은 인위적으로 비폐색을 유발하여 비폐색 부위에 따른 비강자음의 음향학적 변화특성을 파악하고 비음도의 변화 정도를 비교하고자 하였다. 정상비음도를 보이는 성인남녀 각 10명을 대상으로, 2ml의 부피를 갖도록 수술용장갑에 Merocel$^{\circledR}$을 넣은 뒤, 이를 이용하여 ostiomeatal unit(OMU)을 중심으로 전후상하 4부위의 인위적인 비폐색을 유발하여, 비폐색 전과 후의 부위에 빠른 차이틀 비교하였다. /나나/의 발성을 각 조건에서 3회 실시하여, 모음중간의 /ㄴ/중 (CVCV) 안정된 spectorgram소견을 보이는 부위를 선택하여, 해당구간의 제1, 제2, 제3 음형대와 각각의 bandwidth 평균값을 남녀별로 비교하였고, 표준비음비율이 알려진 rabbit, baby, mama 문장을 이용하여 비음비율을 비교하였다. 남녀모두 비폐색전에 비하여 OMU의 앞쪽부위를 막은 경우에 제1음형대가 가장 뚜렷하게 감소되었으며, 비음비율의 유의한 감소를 보였다. 비폐색이 있는 경우, 비강자음 /ㄴ/은 제1음형대를 중심으로 주요변화가 일어남을 알 수 있었으며, 비폐색 부위에 따라 비음비율이나 제1음형대 감소의 정도가 다름을 알 수 있었다.

• The Journal of the Acoustical Society of Korea
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• v.19 no.6
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• pp.28-33
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• 2000

This paper investigates the durational difference between syllable final segment and syllable initial one within word level. The Korean consonant (m) and (nn) were focused mainly. It could hardly say that there was significant difference between preceding consonant and following one, but it was observed that the preceding consonant tended to be shorter than the following one in the (mm) case. This might be explained by the fact that bilabial sound should appear at the first step of language acquisition. This leads to the conclusion that the articulation of preceding (m) shall be easier than others. In the case of alveolar geminate (nn), there was considerable statistic difference between preceding and following segments. It tends to be that the preceding consonant has longer duration.

• The Journal of the Acoustical Society of Korea
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• v.31 no.6
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• pp.353-358
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• 2012

This paper describes acoustic phonetic parameters for detecting nasal place in a knowledge-based speech recognition system. Initial acoustic phonetic parameters are selected by studying nasal production mechanisms which are radiation of the sound through the nasal cavity. Nasals are produced with differing articulatory configuration which can be classified by measuring acoustic phonetic parameters such as band energy ratio, band energy differences, formants and formant differences. These acoustic phonetic parameters were tested in a classification experiment among labial nasal, alveolar nasal and velar nasal. An overall classification rate of 57.5% is obtained using the proposed acoustic phonetic parameters on the TIMIT database.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.19-27
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• 2008

The purpose of this study was to obtain normative nasalance scores for adult subjects speaking the Korean language and to determine whether significantly different scores exist for female and male speakers. Mean nasalance scores were obtained for normal speaking Korean adults while they are reading vowels, consonants, no nasal sentence, mild nasal sentence, and high nasal sentence. Thirty adults who had lived in Seoul area with normal articulation, resonance, and voice were included. Among the subjects 15 were male aged 24-38 years and 15 were female aged 19-33. Nasometer data were collected and analyzed using the Kay Nasometer 6400. Nasalance scores were evaluated to investigate the effect of gender by using statistical tests. Nasalance data showed that nasalance values varied accroding to speech stimuli, and there was no significant difference in nasalance scores between male and female speakers in most of the language samples.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.61-67
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• 2006

We examined seedlings of two species (Ilex rotunda and Illicium anisatum) which have a different level of shade tolerance and raised them under different light regimes (full sunlight and 50% shading). After 12 months, we investigated chlorophyll content (Chl. a, Chl. b and Chl. a+b), photosynthetic systems (photosynthetic rate, light compensation point, dark respiration rate and quantum yield), intercellular $CO_2$ concentration and water use efficiency to show acclimation reaction to different light conditions. Seedlings grown under full sunlight showed lower chlorophyll content than those in the shading regime. There was a significant difference between the full sunlight and shade treatments in I. anisatum (shade tolerance species). I. rotunda (intermediate species) showed high photosynthetic rate and water use efficiency over PPFD $1000\;{\mu}mol\;m^{-2}s^{-1}$ to full sunlight. Also, I. anisatum grown under full sunlight showed lower photosynthetic rate and water use efficiency over a range of all PPFD. This result showed that I. rotunda has a more flexible reaction system than that of I. anisatum.

• Proceedings of the KSLP Conference
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• 1997.11a
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• pp.259-259
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• 1997

폐쇄성 수면무호흡의 치료를 목적으로 한 구개수구개인두성형술 이후의 음성변화 유무를 파악하여, 성악가 등의 전문적인 음성사용자에게 상기한 수술을 결정함에 있어서 가능한 guideline을 제시하여 보고자 하였다. 수면다원검사상 폐쇄성 수면무호흡증으로 진단된 성인남자 20명을 대상으로 수술전후의 음성변화에 대한 설문조사를 하였고, 수술전, 수술후 1개월에 각각 /아/, /이/, /우/ 모음의 제1, 2, 3 음향대를 비교하였으며, 표준 비음비율이 각기 다른 세가지 문장을 이용하여 수술전후의 비음비율의 변화를 측정하였다. 환자 자신은 수술전후의 음성이나 음색의 변화를 느낄 수 없었고, 비음비율의 변화나 모음의 음형대에 대부분은 변화가 없었지만, /우/ 음의 제3음형대 특성에 변화가 있음을 관찰하였고, 구인두가 중요한 역할을 담당할 수 있는 특정언어의 일부 발음이나 vibrato, singer's formant등의 변화유무에 대한 연구가 없는 점을 감안한다면, 성악가를 비롯한 전문적 음성사용자에？서는 구개수 구개인두성형수술을 결정함에 있어 신중을 기하여야 할 것으로 사료되었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.193-198
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• 2011

By a nonnegative sign pattern we mean a matrix whose entries are from the set {+, 0}. A nonnegative sign pattern A is said to allow normality if there is a normal matrix B whose entries have signs indicated by A. In this paper we investigated some nonnegative normal pattern that is different to the pattern in [1]. Some interesting constructions of nonnegative integer normal matrices are provided.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.54-60
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• 2006

The purpose of this study was to examine the reaction in variable light environments on shade tolerant species, Chloranthus glaber. We raised Chloranthus glaber seedlings under four light conditions: PPFD 400, 250, $100\;{\mu}mol\;m^{-2}s^{-1}$ and full sunlight (PPFD $1600\;{\mu}mol\;m^{-2}s^{-1}$). Using 2 years old seedlings, chlorophyll content, photosynthetic rate, stomata conductance and intercellular $CO_2$ concentration were investigated. Shaded seedlings had higher chlorophyll content, photosynthetic rates, and stomatal conductance, but not higher intercellular $CO_2$ concentration than those in the full sun treatment. This result suggested that growth and physiology of Chloranthus glaber adapted to low light intensity.

• Phonetics and Speech Sciences
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• v.15 no.1
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• pp.25-34
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• 2023

This study examined the utility of the acoustic features of vowels as cues for the place of articulation of Korean nasal consonants. In the acoustic analysis, spectral and temporal parameters were measured at the 25%, 50%, and 75% time points in the vowels neighboring nasal consonants in samples extracted from a spontaneous Korean speech corpus. Using these measurements, linear discriminant analyses were performed and classification accuracies for the nasal place of articulation were estimated. The analyses were applied separately for vowels following and preceding a nasal consonant to compare the effects of progressive and regressive coarticulation in terms of place of articulation. The classification accuracies ranged between approximately 50% and 60%, implying that acoustic measurements of vowel intervals alone are not sufficient to predict or classify the place of articulation of adjacent nasal consonants. However, given that these results were obtained for measurements at the temporal midpoint of vowels, where they are expected to be the least influenced by coarticulation, the present results also suggest the potential of utilizing acoustic measurements of vowels to improve the recognition accuracy of nasal place. Moreover, the classification accuracy for nasal place was higher for vowels preceding the nasal sounds, suggesting the possibility of higher anticipatory coarticulation reflecting the nasal place.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1992.10a
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• pp.292-295
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• 1992