• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.31-31
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• 2023

During December 2022, the northeast monsoon, which dominates the south and the Gulf of Thailand, had significant rainfall that impacted the lower southern region, causing flash floods, landslides, blustery winds, and the river exceeding its bank. The Golok River, located in Narathiwat, divides the border between Thailand and Malaysia was also affected by rainfall. In flood management, instruments for measuring precipitation and water level have become important for assessing and forecasting the trend of situations and areas of risk. However, such regions are international borders, so the installed measuring telemetry system cannot measure the rainfall and water level of the entire area. This study aims to predict 72 hours of water level and evaluate the situation as information to support the government in making water management decisions, publicizing them to relevant agencies, and warning citizens during crisis events. This research is applied to machine learning (ML) for water level prediction of the Golok River, Lan Tu Bridge area, Sungai Golok Subdistrict, Su-ngai Golok District, Narathiwat Province, which is one of the major monitored rivers. The eXtreme Gradient Boosting (XGBoost) algorithm, a tree-based ensemble machine learning algorithm, was exploited to predict hourly water levels through the R programming language. Model training and testing were carried out utilizing observed hourly rainfall from the STH010 station and hourly water level data from the X.119A station between 2020 and 2022 as main prediction inputs. Furthermore, this model applies hourly spatial rainfall forecasting data from Weather Research and Forecasting and Regional Ocean Model System models (WRF-ROMs) provided by Hydro-Informatics Institute (HII) as input, allowing the model to predict the hourly water level in the Golok River. The evaluation of the predicted performances using the statistical performance metrics, delivering an R-square of 0.96 can validate the results as robust forecasting outcomes. The result shows that the predicted water level at the X.119A telemetry station (Golok River) is in a steady decline, which relates to the input data of predicted 72-hour rainfall from WRF-ROMs having decreased. In short, the relationship between input and result can be used to evaluate flood situations. Here, the data is contributed to the Operational support to the Special Water Resources Management Operation Center in Southern Thailand for flood preparedness and response to make intelligent decisions on water management during crisis occurrences, as well as to be prepared and prevent loss and harm to citizens.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.2
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• pp.75-85
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• 2023

Objectives: Suspending bisphosphonates (BPs) to reduce the risk and severity of medication-related osteonecrosis of the jaw (MRONJ) remains controversial. In this study, we quantitatively evaluated the clinical significance of BP suspension before surgery in osteoporosis patients with MRONJ. Materials and Methods: We analyzed 24 osteoporosis patients with MRONJ who were treated from 2012 to 2020 at Seoul National University Dental Hospital and compared the treatment outcomes of those who suspended BPs with those who did not. The number of surgical interventions, follow-up panoramic radiographs for relative bone density measurement, and laboratory blood tests including white blood cells, erythrocyte sedimentation rate, absolute neutrophil count, hemoglobin, hematocrit, and alkaline phosphatase were analyzed. ANOVA, Student's t-test, and Mann-Whitney U tests were used to compare results. Fisher's exact test was used to discover the association between treatment outcome and BP suspension, and Pearson's correlation test was used to measure the statistical relationship between the changes in serum inflammatory markers. Results: The number of interventions was significantly higher in the non-drug suspension group due to recurrence (P<0.05). The relative bone density in patients who suspended BPs was significantly different over time (P<0.05), with the highest density at one-year follow-up. Fisher's exact test shows an association between successful treatment outcomes and BP suspension. The alkaline phosphatase and erythrocyte sedimentation rate levels decreased significantly in the BP-suspended group, and a positive correlation was found between these elevated markers. Conclusion: A significant increase in bone density throughout follow-up and a lower number of interventions were found in the BP suspension group compared to the non-drug suspension group. Also, BP suspension decreased inflammatory markers in the serum after surgery, resulting in good treatment outcomes. BP suspension is a prognostic factor for MRONJ and should be implemented before surgery.

• Physical Therapy Korea
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• v.29 no.2
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• pp.117-123
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• 2022

Background: Push-up are effective exercises for shoulder stability. Previous studies have documented the effects of support plane and hand position and width on muscle activities during a push-up. Objects: This study aimed to investigate the changes in muscle activities in the upper extremity when performing the standard and the knee-flexed push-up with different hand shapes. Methods: A total of twenty-six healthy males participated in this study. Three different hand shapes (finger abduction, finger adduction, and fists) and two types of push-up posture (standard and knee-flexed push-up) were set as the independent variables. Electrograms were used to measure the muscle activity of the upper trapezius (UT), triceps brachii (TB), pectoralis major (PM), and serratus anterior (SA). Each participant performed the randomly assigned push-up to the sound of the metronome. The mixed-effect linear regression model was used to detect the changes in muscle activities after changing the hand shape and push-up posture. Statistical significance was set at α = 0.05. Results: The UT muscle activity was statistically significantly higher when performing push-up with fists than finger abduction (p = 0.035) or finger adduction (p = 0.044). During the standard push-up, the muscle activity in all muscles was that the push-up with fists showed the highest muscle activity compared to the finger abduction (p < 0.01) and finger adduction (p < 0.01). Regardless of the shape of the hand, UT had the lowest muscle activity compared to other muscles (p < 0.001). In contrast, the SA muscle had the highest muscle activity among four muscles during the standard push-up. Conclusion: Based on the results of this study, we suggest hand shape is related to the difficulty level of push-up either in the standard or the knee-flexed push-up, especially in the push-up with fists. In addition, knee push-up can be recommended as shoulder muscle-strengthening exercises for individuals with low shoulder muscle strength.

• The Journal of the Society of Stroke on Korean Medicine
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• v.7 no.1
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• pp.17-22
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• 2006

Objectives : Uwhangchungsimwon (UC) is one of the famous herbal medicine frequently used for stroke, hypertension, and atherosclerosis, etc. Therefore, we intended to examine if UC could have therapeutic effect on arterial stiffness by assessing Cardio-Ankle Vascular lndex (CAVI). Methods : We enrolled 38 healthy male subjects (28±4.41 years old) and divided them into two groups (UC and control group). The UC group (N=22) were treated with 1 pill of UC and monitored by CAVI every hour for 6 hours. The control group(N=16) did not receive any medicine and were also monitored by CAVI the same manner as the UC group. In both group, we also assessed each subject's Yin-Yang pattern score by the diagnostic scoring system. In analysis, we compared the difference of CAVIs between the UC and the control group considering subject's Yin-Yang pattern. Results : There was no significant difference in the change of CAVI between the UC and the control group. After excluding Yang-pattern subjects in both group, however, we could observe that CAVI decreased significantly 5 hours after UC administration compared with the corresponding CAVI in the control group (P=0.025). In the repeated measure analysis, the between-subjects effect had statistical significance (P=0.035). Conclusion : According to these results, we suggest that UC have therapeutic effect on arterial stiffness especially after taking oriental medical diagnosis into consideration.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.10-20
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• 2022

Objectives: The aim of this study is to evaluate exposure levels of the extremely low frequency magnetic fields(ELF-MF) radiated from various electric facilities in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the exposure levels of personal and local ELF-MF for the electronic facilities installed in two LCD manufacturing companies. Samplers were installed around workers' waist during working hours to identify personal exposure levels, and direct reading equipment were located at 3 cm, 10 cm, and 30 cm away from the surface of the electronic facilities to measure local exposure levels. Average and maximum(ceiling) values were calculated for personal and local exposure levels. Results: Average and maximum of personal exposure levels for each worker were 0.56(mean) ± 0.02(SE) µT and 6.31 ± 0.75 µT, respectively. Statistical analyses of the study found that maximum of the personal exposure levels for engineers was significantly higher than that for operators since engineers spend more time near the electronic facilities for repairing. The range of maximum personal exposure levels was 0.50 ~ 43.50 µT and its highest level was equivalent to 4.35 % of ACGIH(American Conference of Governmental Industrial Hygienists) exposure limit value(1 mT). Maximum of local exposure levels was 8.18 ± 0.52 µT and the electronic facilities with higher exposure levels were roof rail and electric panel, which were not related to direct manufacturing. The range of maximum local exposure levels was 0.60 ~ 287.20 µT and its highest level was equivalent to 28.7 % of the ACGIH exposure limit value. Lastly, the local exposure levels significantly decreased as the measurement distance from the electronic facilities increased. Conclusions: Maximum of personal and local exposure levels did not exceed the exposure limit value of ACGIH. However, it is recommended to keep the workers as far as possible from the sources of ELF-MF.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.498-502
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• 2007

Today’s teenagers were significantly deficient of calcium intakes, taking on the average only 55.4 percents of the recommended. Milk was the major source of calcium intakes, and therefore the school milk program need to be readdressed to remedy this problem. However, school milk program(SMP) was said to be simply the substitute for milk at home, so that no more than a minimal effect on total milk consumption be warranted. This Study aimed to find out whether or not the school milk program was an effective measure to increase teenager’s milk consumption and explored the relation between school milk and total milk consumption for 1,079 junior and senior high school students who were surveyed by questionnaire from 15th June to 15th July in 2006. A Tobit model was used for the statistical analysis. In this model, we first regressed milk consumption on 5 variables i.e. degree of satisfaction, participation in SMP, sex, school, region. But the variable region was not significant statistically. Then we regressed on 4 variables except for region. The results showed 4 variables were all significant and the marginal effect of variable ‘participation in SMP’ was 1.3. Especially, the marginal effect 1.3 means that the students participating in the school milk program consumed 1.3cups more than the non-participants, which indicated the effectiveness of school milk program to improve the calcium deficiency program of teenagers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.279-289
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• 2006

The reconstruction of low dimension nonlinear behavior from the hydrologic time series has been an active area of research in the last decade. In this study, we present the applications of a powerful state space reconstruction methodology using the method of Support Vector Machines (SVM) to the Great Salt Lake (GSL) volume. SVMs are machine learning systems that use a hypothesis space of linear functions in a Kernel induced higher dimensional feature space. SVMs are optimized by minimizing a bound on a generalized error (risk) measure, rather than just the mean square error over a training set. The utility of this SVM regression approach is demonstrated through applications to the short term forecasts of the biweekly GSL volume. The SVM based reconstruction is used to develop time series forecasts for multiple lead times ranging from the period of two weeks to several months. The reliability of the algorithm in learning and forecasting the dynamics is tested using split sample sensitivity analyses, with a particular interest in forecasting extreme states. Unlike previously reported methodologies, SVMs are able to extract the dynamics using only a few past observed data points (Support Vectors, SV) out of the training examples. Considering statistical measures, the prediction model based on SVM demonstrated encouraging and promising results in a short-term prediction. Thus, the SVM method presented in this study suggests a competitive methodology for the forecast of hydrologic time series.

• Asia Marketing Journal
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• v.15 no.4
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• pp.33-49
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• 2014

Environmental concern has been an important issue for a few decades, and the extent of consumer demand for eco-friendly consumption has been increased. This study seeks to investigate consumers' willingness to pay (WTP) a premium for eco-friendly cosmetics. This study evaluates how much more a consumer is willing to pay for eco-friendly cosmetics and examines significant factors influencing consumers' WTP for eco-friendly cosmetics. Consumers' WTP is measured using four different ecofriendly cosmetics: low-priced skin care cosmetics, low-priced makeup cosmetics, high-priced skin care cosmetics, and high-priced makeup cosmetics. This study uses the contingent valuation method (CVM) to estimate consumer's WTP for eco-friendly cosmetics. Survey questions were designed using both dichotomous choice and payment card method of CVM. Through face to face interviews and on-line surveys, the data were collected from women between 20 and 49 years old residing in Seoul and Kyeonggi area, Korea, in May 2010. A total of 226 questionnaires (132 from interviews and 94 from on-line) were included for the analytical sample in this study. The data were analyzed using descriptive analysis, T-test and Log-Logit analysis. The findings are as follows: First, the WTP measured by dichotomous choice method was estimated using the Log-Logit analysis. The results showed that the estimated WTP for low-priced skin care cosmetics was 19,152 won, which was 27.7% higher than the reference price, 15,000 won. For low-priced makeup cosmetics, the estimated WTP was 18,524 won, and its green premium was 21.0%. The estimated WTP for high-priced skin care cosmetics was 59,128 won, which was 18.3% higher than the reference price, 50,000 won. For high-priced makeup cosmetics was 57,666 won, and its green premium was 15.3%. Second, the WTP measure by payment card method was estimated using descriptive analysis. The results showed that the respondents were willing to pay 17,955 won for low-priced skin care cosmetics, which was 19.7% higher than the reference price, 15,000 won and 17,595 won for low-priced makeup cosmetics, which was 17.3% higher than the reference price. For high-priced skin care cosmetics, the average WTP was 56,950 won which was 13.9% higher than the reference price, 50,000 won. For high-priced makeup cosmetics, the average WTP was 55,650 won, which was 11.3% higher than the reference price. Overall, the WTP was higher in order of low-priced skin care, low-priced makeup, high-priced skin care, and high-priced makeup. It means that consumers decide degree of premium based on the price and the attributes of eco-friendly products. Third, the findings showed that age, monthly income, and having children or not were statistically significant factors that influenced consumers' willingness to pay for eco-friendly cosmetics. Other explanatory variables such as education, marital status, job, purchase experience of eco-friendly products, and environmental concerns did not show any statistical significance. The major contribution of this study is the investigation of the value of green attributes of the products by using CVM. Unlike most previous researches, this research used two methods of CVM, the dichotomous choice and the payment card, so it enhanced the reliability of research. According to this study, consumers showed price sensitivity when they pay green premium. These findings can be used as useful information to establish marketing strategies for green cosmetics.

• Archives of Plastic Surgery
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• v.50 no.5
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• pp.514-522
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• 2023

Background This is a prospective study on 118 patients who underwent lymphaticovenous anastomosis (LVA) due to secondary lower limb lymphedema between January 2018 and October 2020 to evaluate patients' quality of life (QOL) using the Quality of Life Measure for Limb Lymphedema (LYMQoL) questionnaire. Methods The outcome measurement included the LYMQoL leg scoring system tool evaluating the function, appearance, symptom, mood, and overall outcome. In addition, correlation analysis was performed for three factors: based on International Society of Lymphology (ISL) stages, disease duration, and amount of volume reduction. Results The LYMQoL tool overall satisfaction score significantly increased at all intervals from 4.4 ± 0.2 preoperative to 6.5 ± 0.3 postoperative at 12 months (p < 0.001). Significant findings were seen for each domain scores compared preoperatively and at 12 months: function score (18.6 ± 0.5 to 15.4 ± 0.6), appearance score (17.8 ± 0.5 to 16.0 ± 0.6), symptom score (11.8 ± 0.3 to 8.9 ± 0.4), and mood score (14.5 ± 0.4 to 11.4 ± 0.5; p < 0.05). The correlation analysis between improvement of the overall score and the ISL stage (p = 0.610, correlation coefficient [r] = -0.047), disease duration (p = 0.659, r = -0.041), and amount of limb volume reduction (p = 0.454, r = -0.070) showed no statistical significance. Conclusion The QOL of secondary lower limb lymphedema patients was significantly improved after LVA regardless of the severity of disease, duration of disease, and amount of volume reduction after LVA. Understanding the patient-reported outcome measurement will help the surgeons to manage and guide the expectations of the patients.

• Journal of Family Resource Management and Policy Review
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• v.27 no.3
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• pp.1-19
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• 2023

This study aims to develop a family strength scale for dual-earner families with young children. Based on existing theories of family strength and a review of related literature, we draw on 80 items to measure the strength of dual-earner families. Using a sample of 747 people, all members of dual-earner families with young children, we examined the items' factor structures. Using the statistical method, we checked the validity and reliability of these items. The final scale consisted of four domains with a total of 49 items : basic foundation (basic structure, economic life, and resource management), parenting, social interest and participation (citizenship, volunteer, leisure, network), work-life balance (balance between work and family, sharing the family role, equal division of role). The developed scale can be used in the field, such as in the Healthy Family Support Center or Family Center, in the context of education, counseling, or consulting for dual-earner families. In order to enhance the usefulness and efficiency of the scale, the adequate education system for the professionals who handle this scale in the field and updated data are required.