• Journal of dental hygiene science
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• v.17 no.4
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• pp.298-305
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• 2017

This study aimed to investigate the relationship between sleep duration and periodontitis in adult Korean women. This cross-sectional study was based on the 2014 Korea National Health and Nutrition Examination Survey (KNHNES). We selected the data from 3,292 women (over 19 years of age) out of 7,550 participants for analysis, after excluding data from men. Complex logistic regression analysis was performed to determine the effect of sleep duration on the risk of periodontitis; the crude and adjusted odds ratios (ORs) were calculated. The risk of periodontitis was higher in participants who had a sleep duration of 7 hours or more, than in those with less than 7 hours (crude OR) by 1.37 times (95% confidence interval [CI], 1.13~1.65). The adjusted OR of the participants after adjusting for the sample characteristics of the participants (age, education level, income level, diabetes, hypertension, obesity) was 1.04 times (95% CI, 0.82~1.32), but the risk for periodontitis was slightly higher, though not statistically significant. This study confirmed the relationship between sleep duration and the risk of periodontitis in Korean women. Therefore, it is necessary to develop and implement a comprehensive health promotion program that can improve the proper sleeping habits of adult women in Korea and to combine oral hygiene management programs to prevent periodontal disease.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.159-167
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• 2009

With the increase of weight and influence of TV drama, many researchers began to publish papers on TV drama. However, those papers were mainly focused on social meaning and viewing motives and attitudes of TV audience. However, only a few papers researched about television image production techniques, such as 'Relationship between TV ratings and image production techniques', 'Transition process of TV drama's image production techniques', and 'Comparison of TV and film image production techniques'. According to the recent research on the relationship between TV ratings and image production techniques, TV rating is inverse proportionate to multiple camerawork and shot average duration with a very close relationship. The purpose of this thesis is to analyse the relationship between TV genre and image production technique with the data of top 100 of TNS Media Korea from the year 2004 to 2008. This paper found out that history drama uses more closeup, longshot, tracking and less waist shot than other genres, with shorter shot duration and longer scene duration.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.839-850
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• 2018

The flood damage in urban areas due to torrential rain is increasing with urbanization. For this reason, accurate and rapid flooding forecasting and expected inundation maps are needed. Predicting the extent of flooding for certain rainfalls is a very important issue in preparing flood in advance. Recently, government agencies are trying to provide expected inundation maps to the public. However, there is a lack of quantifying the extent of inundation caused by a particular rainfall scenario and the real-time prediction method for flood extent within a short time. Therefore the real-time prediction of flood extent is needed based on rainfall-runoff-inundation analysis. One/two dimensional model are continued to analyize drainage network, manhole overflow and inundation propagation by rainfall condition. By applying the various rainfall scenarios considering rainfall duration/distribution and return periods, the inundation volume and depth can be estimated and stored on a database. The Rainfall-Duration-Flooding Quantity (RDF) relationship curve based on the hydraulic analysis results and the Self-Organizing Map (SOM) that conducts unsupervised learning are applied to predict flooded area with particular rainfall condition. The validity of the proposed methodology was examined by comparing the results of the expected flood map with the 2-dimensional hydraulic model. Based on the result of the study, it is judged that this methodology will be useful to provide an unknown flood map according to medium-sized rainfall or frequency scenario. Furthermore, it will be used as a fundamental data for flood forecast by establishing the RDF curve which the relationship of rainfall-outflow-flood is considered and the database of expected inundation maps.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.3
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• pp.139-149
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• 1994

In many project-oriented production systems, e. g., shipyards or large-scale steel products manufacturing, resource loading by an activity is flexible, and the activity duration is a function of resource allocation. For example, if one doubles the size of the crew assigned to perform an activity, it may be feasible to complete the activity in half the duration. Such flexibility has been modeled by Weglarz [13] and by Leachman, Dincerler, and Kim [7[ in extended formulations of the resource-constrained poject scheduling problem. This paper presents a new algorithmic approach to the problem that combines the ideas proposed by the aforementioned authors. The method we propose involves a two-step approach : (1) solve the resource-constrained scheduling problem using a heuristic, and (2) using this schedule as an initial feasible solution, find improved resource allocations by solving a linear programming model. We provide computational results indicating the superiority of this approach to previous methodology for the resource-constrained scheduling problem. Extensions to the model to admit overlap relationship of the activities also are presented.

• Journal of Nutrition and Health
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• v.31 no.4
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• pp.747-755
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• 1998

In order to study the relationship between body core temperature and adiposity , the core temperatures of normal weight female college students were measured during an instant-noodle lunch eaten in a laboratory at the ambient temperature of 22-24.8$^{\circ}C$. Ambient temperature was positively correlated with meal-start core temperature and meal duration. The difference between the peak postprandial and the meal-start core temperature was negatively correlated with body weight and BMI. This means that the thermogenic response induced by meal consumption was negatively associated with adiposity. Meal duration also showed a negative correlation with body weight, BMI, and hip girth. Thus, the obese eating style characterized by a rapid rate of food intake was also associated with adiposity in normal weight women. It was possibly a contributing factor in the development of obesity. In conclusion, adiposity is negatively associated with the difference between the peak postprandial and the meal-start core temperature and meal duration during a meal.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.82-84
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• 2008

A surface encoder based on the Half-shaded square pattern (HSSP) is presented. The HSSP working as reference grid is composed of the straight lines which are easy to be fabricated and make measuring time short. Since the periodic cell is separated in ON/OFF by the $45^{\circ}$ straight line, the duration from the starting point of scanning to the first rising edge and the duty cycle of the pulse train vary with respect to the position of the starting point. And the relationship between X and Y position and the duration, and duty cycle is described in the simple linear equation. Therefore, it is possible to measure X and Y position with the measured duration and duty cycle without calculating load. Through the test set-up, the feasibility of the proposed surface encoder was verified. Also the future works for improvement of performance were suggested.

• The Korean Journal of Health Service Management
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• v.12 no.4
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• pp.219-228
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• 2018

Objectives : This study was conducted to examine the relationships between Korean adult's daily hours of sleep, depression, and suicidal thoughts using data from the 7th National Health and Nutrition Survey. Methods : This study utilized a depression screening tool, the 9-item Patient Health Questionnaire (PHQ-9), for the 6,355 participants of the health and mental health survey. T-tests, cross analysis, correlation analysis, and logistic regression analysis were used. Results : The results showed that sufficient hours of sleep decreased depression. The depression score for females (3.19) was significantly higher than for males (2.10; p<.001). The participants in the depression group slept less than 7 hours per day (p<.01). Conclusions : The study results showed a significant correlation between sleep duration and depression when health-related factors and social factors influencing sleep were controlled. The results also indicated that this correlation may vary based on gender. This study implies that further studies are necessary to identify the causal relationship between sleep duration and depression.

• Biomedical Science Letters
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• v.9 no.4
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• pp.223-229
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• 2003

The welding workers are frequently exposed to heavy metals such as manganese. Manganese is well evaporated into the air while welding. This study had been carried out to investigate the relationship of the blood manganese level to age, work duration, and smoking status among 128 welding workers in Gyeongnam and Jeonnam province from May to November, 2003. They showed high manganese level in the first health examination. Subjects were also classified for the investigation according to their smoking status as smokers and nonsmokers, work duration ($\leq$9, 10~9, 20$\leq$years), and ages ($\leq$29, 30~39, 40~49, 50$\leq$years). Blood manganese Jevels were analyzed by atomic absorption spectrophotometer (AAS). Mean blood manganese level was 1.62$\pm$0.56 $\mu\textrm{g}$/dl. In the comparison of blood manganese levels by age and smoking status, mean blood manganese levels of smokers in age of 20's, 30's, and 50's were 2.09$\pm$0.44 $\mu\textrm{g}$/dl, 1.94$\pm$0.33 $\mu\textrm{g}$/dl, and 2.l5$\pm$0.33 $\mu\textrm{g}$/dl, respectively. Blood manganese levels of smokers were significantly higher than those of non-smokers, showing no significant difference in the 40's. In the comparison of blood manganese levels by work duration, the blood manganese levels of smokers were the highest in the case of 10 to 19 years work duration. This study showed that the blood manganese levels were related to the smoking status, work duration, and age. Mean manganese levels of smokers showed higher than those of nonsmokers. It also showed that the length of work duration was related to the elevation of blood manganese levels. Among the welding workers, blood manganese levels of smokers were the highest over their age of 50's. In conclusion, smoking was the most significant risk factor to increase blood manganese levels. The further study will need analysis of the other factors related to manganese level elevation.

• Journal of Sasang Constitutional Medicine
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• v.29 no.1
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• pp.40-49
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• 2017

Objectives Sleep duration and sleep quality are closely related to obesity, however there are few studies considering the Sasang constitution. This study is to investigate the relationship between sleep status and obesity according to Sasang constitution. Methods This cross-sectional research studied 2,672 participants (1,293 men and 1,379 women) using the Korean Medicine Data Center (KDC) of the KIOM. Sasang constitution was diagnosed by KS-15 questionnaire. Obesity was divided into two categories: general obesity was defined as Body Mass Index(BMI) ${\geq}25kg/m^2$, and abdominal obesity was defined as waist circumference ${\geq}90cm$ in men and ${\geq}85cm$ in women. Sleep quality was assessed using the Pittsburgh Sleep Quality Index. Results The distribution of the subjects was 56.9% for Taeumin and 43.1% for non-Taeeumin., Poor sleep quality increased both BMI and waist circumference in Taeeumin. In men Taeeumin, sleep duration was correlated with BMI, and sleep quality was correlated with waist circumference. The prevalence of obesity was significant difference according to sleeping duration in men Taeeumin, it was the highest at 6 hours of sleeping time. Conclusions Sleep duration and sleep quality was associated with obesity in Taeeumin. Especially, in men Taeeumin, adequate sleep duration was an important factor for prevention and treatment of obesity.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.1
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• pp.93-102
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• 2016

Objective : This study performed to evaluate that duration of acne scars effects on Qualitative Global Acne Scarring Grading System(QGASC) grade changing and treatment duration. Also this study performed to evaluate the relationship between dysmenorrhea and acne scars, and the effects of each treatment on treatment duration and Korean Acne Grading System(KAGS) and QGASC grade.Methods : 95 patients with acne scars were understood by medical records and case photos, and we evaluated pre and post acne scar grade based on KAGS and QGASC. We analyzed data by SPSS 22 for windows program, and figured out the relation between duration of acne and QGASC grade and treatment duration by Spearman correlation analysis, and performed Mann-Whitney U-test to figure out the relation between dysmenorrhea and QGASC grade. We performed Wilcoxon test to evaluate that treatment of acne scars effects on KAGS grade and QGASC grade, and performed Kruskal-Wallis test to figure out the difference of each treatment which effects on KAGS grade and QGASC grade, and performed Post-hoc analysis to figure out the group comparison.Results & Conclusions : QGASC grade depending on duration of acne was statistically significance. Subcision and Microneedle Therapy System(MTS) and pharmacopuncture were significantly improved acne scars. Other treatments were significantly more effective than subcision and pharmacopuncture combined treatment. Treatment duration of Subcision and MTS combined treatment was significantly most shortest than other treatment.