• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 제11회 음성통신 및 신호처리 워크샵 논문집 (SCAS 11권 1호)
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• pp.323-327
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• 1994

There have been three contrastive claims over the classification of Korean. To answer the classification question, timing variables which would determine the durations of syllable, word and foot were investigated with various words either in isolation or in sentence contexts using Soundcoup/16 on Macintosh P.C., and a total of 284 utterances, obtained from six Korean speakers, were used. It was found 1) that the durational pattern for words tended to maintain in utterances, regardless of position , subjects and dialects 2) that the syllable duration was determined both by the types of phoneme and by the number of phonemes, the word duration both by the syllable complexity and by the number of syllables, and the foot duration by the word complexity, 3) that there was a constractive relationship between foot length in syllables and foot duration and 4) that the foot duration varied generally with word complexity if the same word did not occur both in the first foot and in the second foot. On the basis of these, it was concluded that Korean is a word timed language where, all else being equal, including tempo, emphasis, etc., the inherent durational pattern for words tends to maintain in utterances. The main difference between stress timing, syllable timing and word timing were also discussed.

• 한국관개배수논문집
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• 제19권1호
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• pp.87-96
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• 2012

Information of local solar radiation is essential for many field, including water resources management, crop yield estimation, crop growth model, solar energy systems and irrigation and drainage design. Unfortunately, solar radiation measurements are not easily available due to the cost and maintenance and calibration requirements of the measuring equipment and station. Therefore, it is important to elaborate methods to estimate the solar radiation based on readily available meteorological data. In this study, two empirical equations are employed to estimate daily solar radiation using Cheongju Regional Meteorological Office data. Two scenarios are considered: (a) sunshine duration data are available for a given location, or (b) only daily cloudiness index records exist. Simple linear regression with daily sunshine duration and cloudiness index as the dependent variable accounted for 91% and 80%, respectively of the variation of solar radiation(H) at 2011. Daily global solar radiation is highly correlated with sunshine duration. In order to indicate the performance of the models, the statistical test methods of the mean bias error(MBE), root mean square error(RMSE) and correlation coefficient(r) are used. Sunshine duration and cloudiness index can be easily and reliably measured and data are widely available.

• 가정∙방문간호학회지
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• 제27권2호
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• pp.189-197
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• 2020

Purpose: The purpose of this study was to examine the relationship between sleep duration, quality of sleep and depression, and to identify the factors associated with depression in middle school students. Methods: This study used a cross-sectional design with secondary data, middle school student panel data from the Korean Children and Youth Panel Survey (2018), and data from a total of 2,590 students was used for analysis. For the statistical analysis, t-test, ANOVA, and hierarchical multiple regression were performed using SPSS ver. 26. Results: The mean depression score in adolescents was 17.99±6.38. Depression had significant differences according to sleep duration and quality. Adolescents with less than eight hours of sleep showed the highest depression, and poor sleepers showed higher depression scores than good sleepers. Gender, school achievement, school satisfaction, economic status, and exercise time were found to significantly relate to depression. After controlling for general characteristics, depression explained 17.2% of the variance in quality of sleep (β=-.15, p<.001) and sleep duration (β=-.04, p=.022). Conclusion: These findings indicate that it is necessary to develop intervention strategies to enhance the quality of sleep and appropriate sleep duration for preventing depression in adolescents.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.151-151
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• 2019

Because drought is a complex and stochastic phenomenon in nature, statistical approaches for drought assessment receive great attention for water resource planning and management. Generally drought characteristics such as severity, duration and intensity are modelled separately. This study aims to develop a relationship between drought characteristics using a bivariate copula model. To achieve the objective, we calculated the Standardized Precipitation Index (SPI) using rainfall data at 6 rain gauge stations for the period of 1961-1999 in Jehlum River Basin, Pakistan, and investigated the drought characteristics. Since there is a significant correlation between drought severity and duration, they are usually modeled using different marginal distributions and joint distribution function. Using exponential distribution for drought severity and log-logistic distribution for drought duration, the Galambos copula was recognized as best copula to model joint distribution of drought severity and duration based on the KS-statistic. Various return periods of drought were calculated to identify time interval of repeated drought events. The result of this study can provide useful information for effective water resource management and shows superiority against univariate drought analysis.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• 제61권12호
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• pp.669-673
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• 2018

Background and Objectives Tinnitus, a common complaint of workers who are exposed to noise, can cause substantial negative effects on the quality of life of these workers. The aim of this study was to analyze the characteristics of tinnitus in patients with noise-induced hearing loss and the relationship between tinnitus and the duration of noise exposure. Subjects and Method Thirty-three patients with subjective tinnitus and noise-induced hearing loss were included in this study. Tinnitus questionnaire, Tinnitus Handicap Inventory (THI) and audiological examinations were investigated according to the duration of noise exposure. Results There was a significant correlation between the tinnitus loudness and the duration of noise exposure. Patients who had longer periods of noise exposure had a louder tinnitus and higher THI score. However, there is no significant correlation between the characteristics of tinnitus and aging process. Conclusion The duration of noise exposure influences the loudness and distress of tinnitus. An awareness of tinnitus should be considered as part of hearing conservation program.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권5호
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• pp.247-254
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• 2001

Silent period(SP) is transient stops of muscle activity that are induced by mechanical or electrical stimulus and the duration of silent period is a important parameter that have been associated with symptoms of masticatory dysfunction. Muscle fatigue is induced by sustained muscular contractions. It is associated with the external manifestations as the inability to maintain a desired force output, muscular tremor, and localized pain. Muscle fatigue is a parameter that have been measured or monitored the deterioration of a performance of muscles. On the study of relationship between SP and masticatory muscle fatigue, Nagasawa suggested that SP increases up to 3 min. from the beginning of clenching when the subjects performed sustained contractions at 50% maximum clenching level. In this paper, in order to evaluate a relationship between SP and muscle fatigue, 10 SPs per 1 minute are measured at 10%, 20%, 50% maximum clenching level. We used the median frequency in order to quantify the degree of muscle fatigue. However, the results shows that the duration of silent period was not significantly affected by differing levels of muscle fatigue. Therefore, we suggest that the SP is not increased or decreased as the results of muscle fatigue, also the origin of the SP generation mechanism is discussed.

• 한국물환경학회지
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• 제25권1호
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• pp.125-135
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• 2009

Reliable long-term flows by SWAT-K model were applied to the relationship between stream flow and pollutant load derived from 8-day measured data of Ministry of Environment (MOE) in order to obtain continuous loadograph and evaluate accuracy in water quality modeling for the Chungju dam watershed. The measured flow were compared with flow duration curve from the model, and it showed that measured values corresponded to the almost full range of stream flow conditions except at Odae A. And there was significant relationship ($R^2=0.60{\sim}0.97$) between measured flow and water quality load at all unit-watersheds. Applying this relationship to simulated flows, continuous loadograph was obtained and compared with modeled pollutant loads. Although there were some differences during some dry and flood seasons, those were not significant and overall trend showed a good agreement. From the results, we would be able to derive a continuous loadograph based on measured data at total maximum daily loads (TMDLs) unit-watersheds on a national scale, in which stream flow and water quality have been measured at 8-day intervals since 2004, and this could be helpful to utilize distributed water quality models with difficulty in calibrating and validating parameters from lack of measured data at present.

• Journal of Astronomy and Space Sciences
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• 제38권1호
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• pp.23-29
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• 2021

Utilizing a new version of the sunspot number and group sunspot number dataset available since 2015, we have statistically studied the relationship between solar activity parameters describing solar cycles and the slope of the linear relationship between the monthly sunspot numbers and the monthly number of active days in percentage (AD). As an effort of evaluating possibilities in use of the number of active days to predict solar activity, it is worthwhile to revisit and extend the analysis performed earlier. In calculating the Pearson's linear correlation coefficient r, the Spearman's rank-order correlation coefficient rs, and the Kendall's τ coefficient with the rejection probability, we have calculated the slope for a given solar cycle in three different ways, namely, by counting the spotless day that occurred during the ascending phase and the descending phase of the solar cycle separately, and during the period corresponding to solar minimum ± 2 years as well. We have found that the maximum solar sunspot number of a given solar cycle and the duration of the ascending phase are hardly correlated with the slope of a linear function of the monthly sunspot numbers and AD. On the other hand, the duration of a solar cycle is found to be marginally correlated with the slope with the rejection probabilities less than a couple of percent. We have also attempted to compare the relation of the monthly sunspot numbers with AD for the even and odd solar cycles. It is inconclusive, however, that the slopes of the linear relationship between the monthly group numbers and AD are subject to the even and odd solar cycles.

• 한국작물학회지
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• 제28권4호
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• pp.469-472
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• 1983

아열대 지역에서의 콩생육기간과 수량과의 관계를 구명하고자 1981년 대만 소재 아세아 채소연구개발센터(AVRDC)에서 선발한 콩 482계통을 봄, 여름, 가을 작기에 동일재료를 공시 생산력시험을 실시하여 얻은 결과를 요약하면 다음과 같다. 1. 작기별 평균수량 및 최고수량은 봄작기에서 높았고 가을, 여름 순으로, 낮았으며 가을 작기에서 계통간의 수량차가 제일 적었다. 2. 콩 수량은 작기에 관계없이 생육일수가 증가됨에 따라 증가되었으나 개화일수가 길어짐에 따라 수량은 감소되었다. 3. 100립중은 작기에 관계없이 결실기간이 길수록 무거운 경향을 보였으며 여름과 가을 작기에서 그 관계가 유의적이었다. 4. 다중회귀분석 결과 봄, 여름, 가을 어느 작기에서나 개화일수는 짧고 결실기간이 상대적으로 긴 계통이 고위생산력을 보이는 계통으로 고려되었다.

• 한국수자원학회논문집
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• 제40권8호
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• pp.643-654
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• 2007

본 연구에서는 도로나 도시유역에서와 같은 소유역의 배수시스템에서 적정량의 설계 규모를 결정하기 위해 지속시간 10분 이하의 강우강도-지속시간-재현기간 관계를 유도할 수 있는 방안을 제시하고 검토하였다. 본 연구에서 제시하는 방법은 모포마 분포에 근거한 것이며, 그 적용성을 서울지점 자료에 대한 적용을 통해 확인하였다 본 연구의 결과를 정리하면 다음과 같다. (1) 1분단위 강우자료를 이용하여 빈도해석을 수행한 결과 기존 건설교통부 (2000)에 의해 제시된 강우강도식은 분단위로 외삽할 수 없음을 확인하였다. (2) 60분 집성자료를 모포마 분포에 적용하여 추정한 지속시간별 분단위 연최대치 강우계열은 관측된 분단위 연최대치 강우계열의 특성을 적절히 설명할 수 있는 것으로 파악되었다. (3) 60분 집성자료와 시단위 강우자료를 이용하여 모포마 분포에 적용한 IDF 관계의 차이는 미미한 것으로 나타났다.