• 말소리와 음성과학
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• 제13권3호
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• pp.53-64
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• 2021

일본어의 어두 폐쇄음은 일차적으로 VOT로 구별되며 유성음은 음 값의 VOT, 무성음은 양 값의 VOT를 갖는 것으로 알려져 있다. 최근의 연구에 의하면 유성음이 양 값의 VOT를 갖는 어두 유성 폐쇄음의 무성화 현상이 전국적으로 젊은 층을 중심으로 진행되고 있는 것이 확인되었다. 또한 지역마다 정도의 차이는 있으나 어두 폐쇄음 구별에 VOT 이외에 후속 모음의 F0 차이가 유효한 것이 밝혀졌다. 본고는 산출에 쓰이는 음향 변수 VOT와 F0가 지각 변수로도 유효한지를 검토한 것이다. 4개 지역의 대학생 55명을 대상으로 자연음과 합성음을 이용한 세 가지 지각 실험을 실시한 결과는 어느 지역에서나 어두 폐쇄음의 일차적 지각 변수로 기능하는 것은 VOT이며 예상했던 F0의 사용은 극히 한정적인 것으로 나타났다. F0는 VOT가 기능하지 않을 때에 높은 F0를 무성음으로 지각하는 경우는 있으나 반대로 낮은 F0를 유성음으로 지각하는 경우는 거의 보이지 않았다. 이러한 결과는 유성/무성의 구별에 관여하는 산출의 음향 변수와 지각 변수가 일치하지 않는 것을 뜻하며, 나아가 일차적 변수인 VOT의 구별이 어려운 상황에서도 F0의 적극적인 사용 없이 일상생활에서 유성/무성의 구별에 혼란이 없는 것은 VOT와 F0 이외의 다른 요인이 관여하고 있음을 시사한다. 본고에서는 산출에서 어느 정도 관여가 인정된 모음의 음질(H1-H2)이나 음향 변수가 아닌 문맥이 관여하고 있을 가능성에 대해 논하였으나 이에 대한 검증은 앞으로의 과제로 남아 있다.

• 말소리와 음성과학
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• 제15권1호
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• pp.35-45
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• 2023

일본어의 전통적인 어두 폐쇄음은 파열 전에 성대 진동을 동반하는 유성음과 파열 후에 약간의 기음을 동반하는 무성음으로 이분된다. 한편 도호쿠지방의 유성음은 어느 세대나 파열 전에 성대 진동을 동반하지 않고 무성화한 유성음으로 실현되어 다른 지역과 대조를 이룬다. 무성화한 유성음은 voice onset time(VOT)이 양값으로 나타나고 그러면 기존의 무성음의 VOT와 충돌하게 되어 카테고리 구별에 영향을 미치게 된다. 이에 대해 도호쿠지방의 화자는 생성 시에 다른 지역과는 달리 폐쇄음 구별에 후속 모음의 fundamental frequency(F0)를 적극적으로 사용하는 것이 여러 연구에 의해 확인되었다. 본 연구는 인지면에서도 F0가 폐쇄음 구별에 중요한 역할을 하고 있는지를 밝히기 위해 VOT와 함께 검토한 것이다. VOT와 F0를 재합성한 자극음을 사용하여 도호쿠지방 청자를 대상으로 조건을 달리한 여러 개의 지각실험을 실시하였다. 결과에서는 무의미어의 경우 지역차(도호쿠 지방 vs.주부 지방)는 유의하지 않았으나 유의미어에서는 어휘에 따라 F0 사용에 유의한 차이가 있었으며 이러한 차이는 F0를 적극적으로 사용하는 몇몇의 청자들에게서 기인하는 것으로 밝혀졌다. 논의에서는 이들이 혁신 청자들로 여겨지며 이들을 중심으로 폐쇄음 지각에 F0 역할이 일반화되고 지각특성으로서 F0가 확립될 가능성에 대해 추론해 보았다.

• 음성과학
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• 제14권4호
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• pp.25-39
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• 2007

The present study investigated some perceptual phonetic attributes of two Korean stop types, aspirated and lax, in medial position of an accentual phrase. The intonational pattern across syllables (Jun, 1993) is argued to depend on the type of stop (aspirated vs. lax) only in the initial position of an accentual phrase. In Kang & Dilley (2007), we showed that significant differences between aspirated and lax stops in medial position of an accentual phrase exist in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. In the present perception experiment, we investigated whether these phonetic attributes contribute to the perception of these two types of stops: The closure durations and/or F0's of post-stop vowels on accentual-phrase medial words were altered and twenty native Korean speakers then judged these words as beginning with an aspirated or lax stop. Both closure duration and F0 significantly affected judgments of stop identity. These results indicate that a wider range of acoustic cues that distinguish aspirated and lax Korean stops in production also plays a role in perception. To account for these results we suggest some phonetic and phonological models of consonant-tone interactions for Korean.

• 말소리와 음성과학
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• 제8권1호
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• pp.25-36
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• 2016

Previous studies showed that the voice onset time (VOT) of aspirated and lenis stops has been merged, and post-stop fundamental frequency (F0) has emerged as a primary cue to distinguish the two stops in the younger generation and female speech. The purpose of this study is to demonstrate that VOT merger in aspirated and lenis stops occurs after an F0 difference between the two stops becomes stabilized. In other words, unless post-stop F0, which is a redundant feature, is fully developed, it is hard for VOT merger to happen. Females have got a stable F0 difference in stops earlier than males. Therefore, VOT merger could happen, and as a result, females could take the lead in changing from VOT to F0 in initial stops. This study also shows that speakers who acquired F0 as a primary cue use F0 to the full to distinguish lenis stops from two other stops (aspirated and fortis).

• 음성과학
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• 제11권4호
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• pp.223-232
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• 2004

This study investigated and compared the acoustic characteristics of the Korean stop sound [k'] in three different phonological environments: the tensified lenis stop [k'] as observed in /prek+kaci/, the fortis stop /k'/ as in /pre+k'aci/, and the fortis stop /k'/ following an obstruent as in /prek+k'aci/. The specific research question was whether or not the tensified lenis stop shares all the acoustic features with the other two kinds of fortis stops. The acoustic measures adopted in this study were H1*-H2*, VOT, length of stop closure, and $F_0$. The major findings were that the three stops showed no significant difference in all the acoustic measures except the length of stop closure. The fortis stop /k'/ following an obstruent showed significantly longer duration of stop closure than the other two stops, both of which showed no significant difference. Based on these phonetic results, this study argued that, for the proper phonological description of post-obstruent tensification, the phonological feature [slack vocal folds] of a lenis stop should be changed into [stiff vocal folds, constricted glottis] that the fortis stops should have.

• 음성과학
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• 제14권3호
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• pp.7-19
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• 2007

The present study investigated some phonetic attributes which distinguish two Korean stop types $^-aspirated$ and $lax^-$ in a prosodic position which has previously received little attention, namely medial in an accentual phrase. The intonational pattern across syllables which are initial in an accentual phrase (Jun, 1993) is said to depend on the type of stop (aspirated or lax), while that of syllables which are medial in an accentual phrase are not. In Experiment 1, nine native Korean speakers read sentences with a controlled prosodic pattern in which aspirated or lax stops occurred in accentual phrase-medial position. Acoustic analysis revealed significant differences between aspirated and lax stops in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. The results indicate that a wider range of acoustic cues distinguish aspirated and lax Korean stops than previously demonstrated. Phonetic and phonological models of consonant-tone interactions for Korean will need to be revised to account for these results.

• 구강회복응용과학지
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• 제28권1호
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• pp.57-66
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• 2012

본 연구는 ProTaper Universal에 의도적으로 부여한 내부 응력이 피로 파절에 미치는 영향을 평가하였다. 25 mm 길이의 S1, S2, F1, F2, F3, F4 그리고 F5 파일을 내부 응력을 부여하기 위해서 Endo-Training-Bloc (Dentsply Maillefer)에 auto-stop 될 때까지 속도 300 rpm, 토크 1.0 Ncm의 값으로 밀어 넣었다. 부여한 내부 응력의 횟수에 따라 각각 Stress 0 군(대조군), Stress 1 군, Stress 2 군 그리고 Stress 3 군으로 분류하였다. 경사진 유리판을 사용하였고 파일 파절 시간을 측정하였다. 모든 파일에서는 Stress 3 군은 대조군에 비해 Ni-Ti 파일의 파절 시간이 감소하였고 F2와 F3에서 모든 실험군은 대조군에 비해 파절 시간이 감소하였다. F4와 F5에서 Stress 2 군과 Stress 3 군이 대조군에 비해 파절 시간이 감소하였다. ProTaper Universal의 피로 파절은 파일에 축적된 내부 응력에 의해 영향을 받는다.

• 대한간호학회지
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• 제25권4호
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• pp.653-667
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• 1995

Post - operative wound infections have been a serious problem in nursing care in the operating room and appear to be strongly related to the infection occurring during the performance of operation. The purpose of this study is to identify patterns in duration of surgical hand scrub (SHS), to evaluate the method of SHS and to examine the rate of glove perforation. Subjects for this study include 244 doctors and 169 nurses working in the operative theatre of a hospital in Seoul area. Test samples and related data were collected from this medical facility between April 1, through 15, and July 1, through 5, 1995 by the author and a staff member working in the operating room. For the study, data on the SHS of doctors and nurses were obtained at the time of operation and multiple batches of surgical gloves worn by the operating doctors were collected after each operation. The duration of SHS was measured with a stop watch and the method of SHS was evaluated according to Scoring Hand Scrub Criteria (SHS Criteria) and expressed as SHS scores. For the analysis of the data, t-test was used to compare the differences in the duration and the SHS scores of doctors and nurses, and Pearson's correlation coefficient was used to examine the relationship between the SHS duration and the SHS scores. The results of the study are summarized as follows. 1) The mean time spent in each SHS was 167 seconds in nurses, and 127 seconds in doctors. The data comparing nurses and doctors indicated that there were significant differences in Our ation of SH S between these two groups (t=5.58, p=.000). 2) The mean time spent in the first SHS was 145 seconds and that in the End SHS, 135 seconds, and there was not a significant difference in the duration of the SHS between doctors and nurses (t=1.44, P=.156). 3) The mean time spent in the SHS by OS (Orthopaedic surgery) doctors was 162 seconds, 150 seconds by NS(Neurologic surgery), 121 seconds by GS(General surgery), 94 seconds by OPH(Opthalmology) and DS(Dental surgery), 82 seconds by URO(Urology), 78 seconds by PS(Plastic surgery) and 40 seconds by ENT(Ear, Nose & Throat) These also showed a significant difference in the duration of the SHS among the medical specialities (t=4.8, P=.0001). 4) The average SHS score of the nurses was 15.2, while that of doctors was 13.1. The statistical analysis showed that t-value was 3.66, p was. 000. This indicates that the nurses actually clean their hands more thoroughly than the doctors do. 5) The average SHS score of NS doctors was 15.5, 15.3 for doctors for OPH,14.3 for OS,12.7 for GS, 12.0 for DS, 11.7 for URO, 10.1 for PS, 7.5 for ENT. Comparison of the average SHS scores from 8 specialties showed that there was a significant differences in the patterns of the SHS (F=5.08, P=.000) among medical specialties. 6) It appears that the operating personnel scrub the palms and dorsum of their hand relatively well, however, less thorough the nails and fingers. 7) The more the operating personnel spend their time in hand scrubbing, the more correctly they clean their hands(r=.6427, P<.001). 8) The overall frequencies of perforation in all post-operative gloves tested was 38 out of 389 gloves (10.3%). The perforation rate for PS was 13%, 12.1% for GS,8.8% for 05, and 3.3% for NS.