• Proceedings of the Acoustical Society of Korea Conference
• /
• 1994.06c
• /
• pp.323-327
• /
• 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.

• KCID journal
• /
• v.19 no.1
• /
• pp.87-96
• /
• 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.

• Journal of Home Health Care Nursing
• /
• v.27 no.2
• /
• pp.189-197
• /
• 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.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.151-151
• /
• 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
• /
• v.61 no.12
• /
• pp.669-673
• /
• 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.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.50 no.5
• /
• pp.247-254
• /
• 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.

• Journal of Korean Society on Water Environment
• /
• v.25 no.1
• /
• pp.125-135
• /
• 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
• /
• v.38 no.1
• /
• pp.23-29
• /
• 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.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.4
• /
• pp.469-472
• /
• 1983

Seasonal variations influence the growth duration and yield of soybeans in the tropics and subtropics. Results of different yield trials were used to determine the relationship between yield with days to R$_1$ and R$_{8}$ in different seasons. Similarly relationship for 100 seed weight was examined. Multiple regression equations suggest that increase in yield can be obtained by increasing the days to R$_{8}$ regardless of seasons. However, increasing the days to R$_1$ invariably reduced the yield. The longer the time from R$_1$ to R$_{8}$, the higher the 100 seed weight. Since the population examined was heterogeneous for photoperiod sensitivity, the need to examine photoperiod sensitive and insensitive selections separately is discussed.

• Journal of Korea Water Resources Association
• /
• v.40 no.8
• /
• pp.643-654
• /
• 2007

This study proposes and evaluates a methodology for deriving the rainfall intensity- duration-frequency relationship for durations less than 10 minutes used for designing drainage systems in small urban catchments and roads. The method proposed in this study is based on the Moupfouma distribution, which has been evaluated by applying it to the rainfall data at the meteorological Seoul station. Summarizing the results is as follows: (1) The frequency analysis results using minutely rainfall data was found not to be corresponded with the extrapolation of that by the Ministry of Construction and Transportation (2000). (2) The annual maxima minutely rainfall data derived by applying the Moupfouma distribution to the accumulated 60-minute data was found to well reproduce the characteristics of those of observed. (3) The rainfall intensity-duration-frequency relationship derived by applying the Moufouma distribution to the accumulated 50-minute data and hourly data was found insignificant.