• 말소리와 음성과학
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• 제11권2호
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• pp.23-31
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• 2019

The present study examines whether pitch range variation in North Kyunsang Korean shows a categorical or continuous function. Specifically, the study is focused on the data imitated by adults and children in the North Kyungsang region. To investigate pitch range variation, the log-produced f0 intervals were measured and statistically analyzed. The results of the study are as follows. First, both the adults' and children's imitations were more categorical than continuous, especially for the HL-LH patterns. For the other pitch accent patterns, such as HH-HL and HH-LH, the curves were continuous or flat for most of the speakers. Second, the children's imitations were poorer than those of the adults. That is, the children's imitative responses were shown as more continuous or flat curves than categorical. For the children, the HL-LH pattern showed a categorical function at the midpoint of the curves, though the shifts were not as distinctive as the adults' data. This implies that the imitative responses of children follow the perceptual and productive trace of adults' speech behavior.

• 말소리와 음성과학
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• 제5권2호
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• pp.59-69
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• 2013

The purpose of this study is to examine the variation of pitch contour observed in the reading of Korean sentences produced by Chinese Korean-learners. In the reading context, Korean sentence intonation can be described by considering accentual phrases' pitch pattern and intonational phrases' boundary tone. But when APs and IPs connect to each other to form sentences, another aspect of speech production must be considered, that is declination of pitch contour. So, in order to examine how Chinese speakers produce Korean sentence intonation, we have analysed the sentences' pitch contours produced by fourteen Chinese speakers differing in proficiency, and compared them to pitch contours produced by six Korean native speakers. The results show that Chinese speakers tend to decline the pitch contour in shorter sentences, but for longer sentences, the declination was not observed. Moreover, even though Chinese speakers produced sentences with declination, internal tonal modulation differs from native speakers.

• 음성과학
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• 제4권2호
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• pp.115-139
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• 1998

The aim of this study is to develop an the assessment program for the singing voice which is based on the physiological and acoustic methods. 22 sopranos, 6 mezzo sopranos, 4 tenors and 4 baritones participated to these experiments. The results measured by Visi-Pitch, spectrograph, and strobo-scope can be summarized as follows: (1) The maximum phonation time of singers must over 14 second higher with one deep inspiration (2) The parts classified by vocal range using Visi-Pitch: soprano between 167Hz $\sim$1,190Hz, mezzo soprano between 146Hz$\sim$956Hz, tenor between 75Hz$\sim$503Hz and baritone between 73 Hz and 385 Hz. (3) Longitudinal glottal size of singers decreases depending on the high-low pitch variation while lattitudinal glottal size increases depending on high-low pitch variation. (4) Well-trained singers show over 5 times the vibrato rate of untrained singers and regular pitch variation during measured periods. Vibrato's intensity do not over 3 dB. (5) Singer's formant indicates professional voice depending on the each parts: 3,207 Hz for soprano, 3,057 Hz for mezzo soprano, 2,754 Hz for tenor and 2,560 Hz for baritone.. (6) $F_1$ of singing voice is higher than that of speech while $F_2\;and\;F_3$ of singing voice are lower than those of speech.

• 말소리와 음성과학
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• 제13권4호
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• pp.35-46
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• 2021

본 연구는 제 2언어 억양습득 과정에서 나타나는 언어 보편적 간섭현상인 피치대역(음역) 축소현상과모국어 간섭현상이 어떤 양상으로 상호작용하며 한국어 습득과정에서 어떤 순서로 나타나는지 중국인 한국어 학습자들을 통해 살펴보았다. 본 연구에는 7명의 한국어 원어민 화자와 초·중·고급 수준의 중국인 한국어 학습자 각 10명 총 37명이 발화 실험에 참여하였다. 연구 참여자들은 난이도가 다른 한국어 담화 4개와 이를 중국어로 번역한 중국어 담화 4개를 낭독 발화하였다. 한국어화자와 중국인 학습자들이 산출한 음성자료는 음성분석 프로그램 Praat을 사용하여 각 문장별로 Pitch span, Pitch level, Pitch dynamic quotient(PDQ), 왜도와 첨도를 측정하였고 이후 언어 간 분석, 그룹 간 분석, 그룹 내 분석을 통해 두 현상의 상호작용양상을 살펴보았다. 언어 간 분석결과 중국어는 한국어보다 높은 Pitch span과 Pitch level로 특징지어졌다. 이를 바탕으로 초·중·고급 중국인 학습자들의 한국어 발화문에 대한 그룹 간 분석을 실시하였다. 그 결과 초급과 중급 학습자들에게서는 모국어 간섭보다는 음역 축소현상이 두드러지게 나타났으며 고급 학습자들은 음역 축소현상이 완화되어 한국 화자에 근접한 양상을 보여주었다. 중국인 학습자들이 발화한 목표어인 한국어와 모국어인 중국어 문장을 대상으로 한 그룹 내 분석에서도 숙달도가 높을수록 모국어와 목표어 간 피치 편차가 줄어들어 음역 축소현상이 완화되었다. 문장 내 피치 변동 범위를 파악하기 위한 PDQ분석에서 중국어 문장은 한국어 문장보다 음역 변동범위가 크다는 것을 알 수 있었다. 그룹 간 분석에서는 초·중급 학습자들의 PDQ가 한국어와 중국어보다 현저히 낮은 값을 보였다. 고급학습자들도 한국어나 중국어보다 낮은 수치를 보였으나 한국어에 근접한 양상으로 나타났다. 이상의 결과를 바탕으로 숙달도가 낮은 화자일수록 음역 축소 현상이 두드러지게 나타나며 고급 화자의 경우 목표어인 한국어와 유사한 양상으로 실현됨을 알 수 있었다. 따라서 본 연구의 분석 대상인 음성학적 층위에서는 모국어 간섭현상이 뚜렷하게 관찰되지 않았다.

• 한국전산유체공학회지
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• 제17권3호
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• pp.39-44
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• 2012

In this study, a longitudinal pitch effect on in-line tube bank heat transfer has been analyzed numerically. To verify the accuracy of the solver model and boundary conditions, global Nusselt number(Nu) and pressure drop across the 2 row tube bank are compared with the existing experimental correlations under 500 ~ 2,000 Reynolds number(Re) range. By changing transverse pitch($S_T$) or longitudinal pitch($S_L$) separately in tube bank, we're trying to identify the each effect on heat transfer. We found that the effect of transverse pitch can be accounted for Reynolds number evaluated with maximum velocity($V_{max}$) at the smallest flow area similar to most existing correlations. Variation of the longitudinal pitch($S_L$) has a greater impact on the heat transfer compared to the transverse pitch($S_T$). Overall Nusselt number increases with larger longitudinal pitch($S_L$), however individual Nusselt number of the tube row has significant difference after the first row.

• Journal of Mechanical Science and Technology
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• 제19권8호
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• pp.1632-1648
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• 2005

The effects of Reynolds number on the non-nulling calibration of a typical cone-type five-hole probe have been investigated for the representative Reynolds numbers in turbomachinery. The pitch and yaw angles are changed from - 35 degrees to 35 degrees with an angle interval of 5 degrees at six probe Reynolds numbers in range between $6.60{\times}10^3\;and\;3.17{\times}10^4$. The result shows that not only each calibration coefficient itself but also its Reynolds number dependency is affected significantly by the pitch and yaw angles. The Reynolds-number effects on the pitch- and yaw-angle coefficients are noticeable when the absolute values of the pitch and yaw angles are smaller than 20 degrees. The static-pressure coefficient is sensitive to the Reynolds number nearly all over the pitch- and yaw-angle range. The Reynolds-number effect on the total-pressure coefficient is found remarkable when the absolute values of the pitch and yaw angles are larger than 20 degrees. Through a typical non-nulling reduction procedure, actual reduced values of the pitch and yaw angles, static and total pressures, and velocity magnitude at each Reynolds number are obtained by employing the calibration coefficients at the highest Reynolds number ($Re=3.17{\times}10^4$) as input reference calibration data. As a result, it is found that each reduced value has its own unique trend depending on the pitch and yaw angles. Its general tendency is related closely to the variation of the corresponding calibration coefficient with the Reynolds number. Among the reduced values, the reduced total pressure suffers the most considerable deviation from the measured one and its dependency upon the pitch and yaw angles is most noticeable. In this study, the root-mean-square data as well as the upper and lower bounds of the reduced values are reported as a function of the Reynolds number. These data would be very useful in the estimation of the Reynolds-number effects on the non-nulling calibration.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2003년도 5월 학술대회지
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• pp.43-47
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• 2003

This paper is phonetic study of $F_{0}$ range and boundary tone in Mandarin Chinese. The production data from 6 Chinese speakers show that there are declination, pitch resetting and tonal variation of boundary tone. In declarative sentence, $F_{0}$ declines gradually over the utterance but mid-sentence boundary prevents $F_{0}$ of following syllable from declining because of pitch resetting. $F_{0}$ range of syllable is expanded before the mid- and final sentence boundaries. In interrogative one, $F_{0}$ ascends gradually over the utterance and mid-sentence boundary makes $F_{0}$ of following syllable rise more. $F_{0}$ range of sentence final syllable is expanded and $F_{0}$ contour shows rising curve.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.30-34
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• 2001

In the present study, we studied the method of predicting the on-design and on-design point performance of axial flow fan with adjustable pitch blades. With the change of stagger angle of axial flow fan with adjustable pitch blade, flow rate and pressure can be changed. Because of this merit adjustable pitch fans are used in many industrial facility. When changing stagger angle or estimating the performance at a wide range of off-design condition, incidence angle changes greatly as the flow rate changes. Therefore, the deviation angle at the blade exit is estimated by the correlation considering the effects of blade design, incidence angle variation. In the loss model, we used known pressure loss model for blade boundary layer and wake, secondary flow, endwall boundary layer and tip leakage flow. The results of modified deviation angle model and experiment were compared for the usefulness of the modified model.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.27-36
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• 1984

This study was carried out to investigate the effects of the tilling depth, tilling travel speed and soil shear stress on the tilling load characteristics and power requirement for rotary tillers. The results obtained from the study are summarized as follows. 1. The average and maximum PTO torque increased as the tilling depth, tilling pitch and soil shear stress increased. A multiple linear regression equation to estimate the average PTO torque in terms of the above parameters was developed. 2. The ratios of maximum PTO torque to the average torque were in the range of 1.17 to 1.65 for the various tilling conditions tested. The variation in PTO torque increased greatly as the tilling pitch and soil shear stress increased, but decreased as the tilling depth increased. 3. Power requirement for the PTO shaft increased with the tilling depth, travel speed and soil shear stress, but decreased slightly as the tilling pitch increased. A multiple linear regression equation to estimate power requirement for the PTO shaft in terms of the above parameters was developed. 4. The specific power requirement for the rotary tiller was in the range of $0.008-0.015ps/cm^2$ for the various tilling conditons tested. The specific tilling capacity decreased as the tilling depth and soil shear stress increased, but increased with the tilling pitch. A multiple linear regression equation to estimate the specific tilling capacity in terms of the above parameters was developed.

• 음성과학
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• 제8권1호
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• pp.7-19
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• 2001

The acoustic parameters of nine Korean numbers were analyzed by Praat, a speech analysis software, and synthesized by SenSynPPC, a Klatt formant synthesizer. The overall intensity, pitch and formant values of the numbers were modified dynamically by a step of 1 dB, 1 Hz and 2.5% respectively. The study explored the sensitivity of listeners to changes in the three acoustic parameters. Twelve subjects (male and female) listened to 390 pairs of synthesized numbers and judged whether the given pair sounded the same or different. Results showed that subjects perceived the same sound quality within the range of 6.6 dB of intensity variation, 10.5 Hz of pitch variation and 5.9% of the first three formant variations. The male and female groups showed almost the same perceptual ranges. Also, an asymmetrical structure of high and low boundary was observed. The ranges may be applicable to the development of a speaker identification system while the method of synthesis modification may apply to its evaluation data.