• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.3
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• pp.100-116
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• 1993

It is experienced fact that unreasonable design criterion and unsitable operation management for the agricultural structures including reservoirs based on short terms data of monthly flows have been brought about not only loss of lives, but also enormous property damage. For the solution of this point at issue, this study was conducted to simulate long series of synthetic monthly flows by multi-season first order Markov model with selection of best fitting frequency distribution and to make a comparison of statistical parameters between observed and synthetic flows of six watersheds in Yeong San and Seom Jin river systems. The results obtained through this study can be summarized as follows. 1.Both Gamma and two parameter lognormal distribution were found to be suitable ones for monthly flows in all watersheds by Kolmogorov-Smirnov test while those distributions were judged to be unfitness in Nam Pyeong of Yeong San and Song Jeong and Ab Rog watersheds of Seom Jin river systems in the $\chi$$^2$ goodness of fit test. 2.Most of the arithmetic mean values for synthetic monthly flows simulated by Gamma distribution are much closer to the results of the observed data than those of two parameter lognomal distribution in the applied watersheds. 3.Fluctuation for the coefficient of variation derived by Gamma distribution was shown in general as better agreement with the results of the observed data than that of two parameter lognormal distribution in the applied watersheds both in Yeong San and Seom Jin river systems. Especially, coefficients of variation calculated by Gamma distribution are seemed to be much closer to those of the observed data during July and August. 4.It can be concluded that synthetic monthly flows simulated by Gamma distribution are seemed to be much closer to the observed data than those by two parameter lognormal distribution in the applied watersheds. 5.It is to be desired that multi-season first order Markov model based on Gamma distribution which is confirmed as a good fitting one in this study would be compared with Harmonic synthetic model as a continuation follows.

• Journal of Korean Biological Nursing Science
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• v.18 no.2
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• pp.102-109
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• 2016

Purpose: The purpose of this study was to describe sports injuries among elderly people and to compare physical activity, perceived health status and exercise self-efficacy between elderly people who had experienced a sports injury and elderly people who hadn't. Methods: The sample of this study were 100 elderly in Korea, 51 of whom had had a sports injury. The study used questionnaires to gather data. There were 8 demographic factors, 4 factors related to physical activity, perceived health status and exercise self-efficacy of the subjects. Data were analyzed by frequencies, chi-square test, and t-test. Result: Among the sports injured elders, one occurrence of a sport injury was 86.3%. There were more outdoor than indoor sports injuries of elders (66.7%), and sports injuries of elders occurred more in the winter (82.7%). The major cause of the sports injuries was loss of balance. Ankles were frequently damaged from these injuries. The most significant change after the sports injury was reduction of physical activity (60.8%). There were significant differences between sports injured elderly and non-injured elderly for age (${\chi}^2=2.58$, p=.011) and the amount of physical activity (t=1.96, p=.050), but there was no significant difference in perceived health status and exercise self-efficacy. Conclusion: To prevent sports injuries in the elderly means to maintain a medium level of physical activity and to improve their balance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1599-1605
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• 2014

This study aimed to identify the relationship between depression of the elderly and low back pain. Data were obtained from cross-sectional surveys conducted as a part of the Community Health Survey 2008. The final analysis included data from 3,647 of the 3,649 elderly participants (aged over 65 years), as 2 responses were excluded since they were inaccurate. Data were analyzed with SPSS for Windows (ver. 19.0), using a Rao-Scott ${\chi}^2$-test and Logistic regression by applying a proper weighting. The significance threshold was set as p<0.05. Factors related to the depression of the elderly were low back pain, subjective health status, average sleep duration. Further, depression score was 1.38 times higher in elderly adults with low back pain than elderly adults without low back pain. In order to decrease depression of the elderly with low back pain the development of a program to decrease activities of daily living discomfort and management of low back pain will need to be determined. It is considered necessary to conduct further study to follow through the analysis of the various variables by applying them to the elderly with low back pain and depression.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.118-128
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• 2023

Background: The use of heated tobacco products (HTP) causes many adverse health effects. Although the use of HTP by adolescents is prevalent worldwide, research related to it is very limited. There is a considerable lack of research related to the current HTP use rather than ever-HTP use. In particular, research related to predictive factors for current HTP use in adolescents is scarce. Objectives: The purpose of this study was to analyze related characteristics according to the current use of HTP among South Korean adolescents. Methods: This was a cross-sectional study that used data from the Seventeenth Korean Youth Risk Behavior Web-based Survey (KYRBWS). A total of 54,848 students in 2021 were included in this study. Chi-square-test, multiple logistic regression analysis, and chi-square test for trend were used for analyzing related characteristics according to use of HTP. Results: Overall, 715 (1.3%) students responded as having used HTP during the last 30 days among the 54,848 students. It was found that residence type, subjective body type recognition, subjective health recognition, alcohol use, habitual drug experience, close friend current smoking, and conventional cigarette smoking were significantly associated characteristics with the current use of heated tobacco products. Comparing 'very thin recognition' with 'very fat recognition', the adjusted odds ratio (OR) was 1.93 (95% confidence interval [CI]: 1.29~2.87) for current use of HTP. Additionally, comparing 'very unhealthy recognition' with 'very healthy recognition', the aOR was 3.82 (95% CI: 2.40~6.07) for current use of HTP. Conclusions: Based on these results, residence type, subjective body type recognition, subjective health recognition, alcohol use, habitual drug experience, close friend current smoking, and conventional cigarette smoking were associated with significantly increased odds of current HTP use. Therefore, the results of this study can provide useful evidence about adolescent behaviors in predicting current HTP use.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.1
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• pp.37-47
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• 2023

A new clamped mechanical splice system was proposed to develop structural performance and constructability for precast concrete connections. The proposed mechanical splice resists external loading immediately after the engagement. The mechanical splices applicable for both large-scale rebars for plants and small-scale rebars for buildings were developed with the same design concept. Quasi-static lateral cyclic loading tests were conducted with reinforced and precast concrete members to verify the seismic performance. Also, shaking table tests with three types of seismic wave excitation, 1) random wave with white noise, 2) the 2016 Gyeongju earthquake, and 3) the 1999 Chi-Chi earthquake, were conducted to confirm the dynamic performance. All tests were performed with real-scale concrete specimens. Sensors measured the lateral load, acceleration, displacement, crack pattern, and secant system stiffness, and energy dissipation was determined by lateral load-displacement relation. As a result, the precast specimen provided the emulative performance with RC. In the shaking table tests, PC frames' maximum acceleration and displacement response were amplified 1.57 - 2.85 and 2.20 - 2.92 times compared to the ground motions. The precast specimens utilizing clamped mechanical splice showed ductile behavior with energy dissipation capacity against strong motion earthquakes.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.213-222
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• 2018

This study purposed to verify the effects of knee balance taping therapy on knee pain and knee range of motion in the elderly with knee pain. The Quasi-experimental design, nonequivalent control group pretest-posttest was used in this study. Data collected from December 5 to 10, 2014. The participants were older than 60 with knee pain visiting senior community centers. Non-medicated elastic tapes were applied around the knee in the experimental group(n=21) and were not applied in the control group(n=19). Knee pain and range of motion were measured 3 times (before, after 1 hour, after 24 hours). Data were analyzed using ${\chi}^2$ test, Fisher's exact test, Mann-Whitney test, t-test, Repeated measure ANOVA with the SPSS version 21.0 program. The experimental group showed significantly decreased knee pain (F=34.03, p<.001) and increase in knee range of motion (F=7.83, p=.006). The results of this study confirm that knee balance taping therapy is an effective intervention for reducing pain and improving range of motion in elderly with knee pain.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.465-476
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• 2019

This study was convergence study to determine sleep and its factors in university students on the basis of Spielman's 3P model. The participants were 191 graduate and undergraduate students who were scheduled to take the exam after 1~2 weeks. The related variables of quality of sleep were self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Chi-square test and t-test were used to make a comparison of the quality of sleep between the good and the bad sleep quality group. Pearson's coefficient correlation analysis was performed for correlation between the quality of sleep and the general characteristics, self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Stress and test anxiety as precipitating factors for sleep disturbance, smartphone dependency as a perpetuating factor for sleep disorder, and daytime sleepiness as a sleep-related factor were correlated with the quality of sleep; no statistically significant correlation was found with self-control as a predisposing factor in the biopsychological area. It is necessary to solve such problems with mental health as stress and test anxiety, which are factors for sleep disturbance, and smartphone dependency as a perpetuating factor for sleep disorder, in pursuit of higher quality of sleep for university students.

• Journal of East-West Nursing Research
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• v.25 no.2
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• pp.103-116
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• 2019

Purpose: This study investigated the effects of the Seogeum therapy among college students with allergic rhinitis. Method: A non-equivalent control group pretest-posttest non-synchronized design was used. Intervention of Seogeum therapy has been performed from March 2 through March 31, 2017. Sixty college students diagnosed with allergic rhinitis from two different colleges in B and K cities were assigned to the experimental and control group. Data analysis were conducted using descriptive statistics, chi-square test, Fisher's exact test, and t-test. Results: There were significant differences in nose itching (t=4.89, p<.001), sneezing (t=6.26, p<.001), watery rhinorrhea (t= 4.09, p<.001), nasal congestion (t=2.36, p=.022), the percent of eosinophil (t=2.01, p=.049), perceived stress (t=2.05, p=.045), and allergic rhinitis related quality of life (t=4.33, p<.001) between the two groups. However, there were no significant differences in the percent of IgE (t=0.60, p=.553) and level of cortisol (t=0.53, p=.598). Conclusion: The results of this study indicates that the self-management of Seogeum therapy improved physical and psychological status of the college students with allergic rhinitis which ultimately improved their quality of life.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.106-114
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• 2021

This study was conducted to provide basic data for the systematic management and preservation of Nak-nam Jeongmaek. Of the Nak-nam Jeongmaek, six priority research areas, Gilmajae, Mt. Cheonwang, Mt. Yeohang, Mt. Muhak, Mt. Cheonju, Mt. Sineo, with consideration to terrain and environmental characteristics, were selected for this study. Two fixed plots for each bird habitat type were selected for each site and were surveyed from May to October in 2018. The survey conducted in the six priority research areas of Nak-nam Jeongmaek identified 48 species with 1,181 individual birds. The largest number of species and individuals occupying a particular habitat type were found in the developed land with 35 species and 567 individuals. Species diversity was the highest at 2.66 in the forest road. According to the results of nesting guild analysis of Nak-nam Jeongmaek (Pearson Chi-square test, 𝛘²=16.681, p<0.05) by each habitat type, the communities that belong to the canopy nesting guild showed a high frequency in the developed land, the valley, and the forest road. The results of the Pearson Chi-Square test (𝛘²=16.217, p<0.005) showed that the communities that belonged to the bush foraging guild were the most frequent in the developed land, and the communities that belonged to the canopy foraging guild were the most frequent in the valley and the forest road. The results of these studies suggest that the various habitats of the Nak-nam Jeongmaek provide a variety of resources for bird habitats.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.111-119
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• 2013

It is essential and fundamental to extract boundary information of target object via massive three-dimensional point data acquired from laser scanner. Especially extracting boundary information of manmade features such as buildings is quite important because building is one of the major components consisting complex contemporary urban area, and has artificially defined shape. In this research, extended ${\chi}$-algorithm using geometry information of point data was proposed to extract boundary information of building from three-dimensional point data consisting building. The proposed algorithm begins with composing Delaunay triangulation process for given points and removes edges satisfying specific conditions process. Additionally, to make whole boundary extraction process efficient, we used Sweep-hull algorithm for constructing Delaunay triangulation. To verify the performance of the proposed extended ${\chi}$-algorithm, we compared the proposed algorithm with Encasing Polygon Generating Algorithm and ${\alpha}$-Shape Algorithm, which had been researched in the area of feature extraction. Further, the extracted boundary information from the proposed algorithm was analysed against manually digitized building boundary in order to test accuracy of the result of extracting boundary. The experimental results showed that extended ${\chi}$-algorithm proposed in this research proved to improve the speed of extracting boundary information compared to the existing algorithm with a higher accuracy for detecting boundary information.