• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.214-214
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• 2019

가뭄이 '심함' 단계 이상 도달 시에는 매주 수문분석을 수행하여 가뭄전망을 수행하여야 한다. 이를 위해서는 기상청의 강수량과 기온 등의 기상예측 자료가 필요하다. 현재 기상청에서는 3개월 기상전망으로 월단위 강수량과 평균기온을 매월 제공하고 있다. 1개월 전망에서 4주의 강수량합과 평균기온을 제공하고 있다. 하지만, 향후 4주간을 전망하는 1개월 전망에서는 1주단위의 강수량과 평균기온이 아닌, 4주간의 강수량합과 평균기온을 1주일 단위로 업데이트해 WINS에 제공하고 있다. 1주단위의 강수량과 평균기온을 취득하기 어려워, 평년 일단위 강수량과 평균기온 자료를 사용하여 4주간의 자료를 1주 단위로 분할하는 방법을 사용하였다. 주간단위 수문자료의 처리를 위해 국제표준기구(ISO)에서 제시하는 기준(ISO 8601)에 따랐다. ISO 8601은 월요일부터 일요일까지를 1주로 정의하며 현재 사용하고 있는 날짜체계와 1대1로 대응되도록 하였다. 예를 들면 1981년 2월 22일은 '1981-W07-7' 또는 '1981W077'로 표시한다. 표시된 형식은 1981년 7번째 주 일요일을 뜻한다. 이 기준에 따라 수문자료를 정리할 수 있도록 프로그램을 개발하였다. 주간 단위 잠재증발산량 계산은 월잠재증발산량 프로그램을 1주단위로 계산할 수 있도록 수정 및 보완하여 개발하였다. 수정 및 보완한 부분은 외기복사(外氣輻射)량 계산부분이다. 외기복사량은 지구가 태양을 1년 주기로 공전하므로 특정 위도에서 특정날짜에 따라 복사량이 달라지므로 주간단위의 월요일부터 일요일에 해당하는 날짜의 외기복사량을 각각 계산하고 이를 평균하여 주간단위 대푯값으로 사용하도록 하였다. 계산된 주간단위 외기복사량과 최고 최저기온을 입력하여 Hargreaves식에 의해 잠재증발산량을 계산한다. 융적설을 포함한 주단위 강우-유출 모형의 매개변수를 추정하기 위해 전국 24개 지점의 수문자료를 사용하였다. abcd 모형과 융적설모듈의 초기값 포함 11개 매개변수를 SCE-UA 전역최적화 알고리즘으로 추정하였다. 추정된 유역의 매개변수는 토양배수, 토양심도, 수문지질, 유역특성인자를 사용한 군집분석 결과에 의해 113개 중권역에 할당하였다. 개발된 주간단위 강우-유출 모형은 비교적 단기 가뭄전망을 위해 사용된다. 계산된 유량은 자연유량이며, 전국 취수장 수량, 하수처리장 방류수, 회귀수를 반영하여 지점별 유량을 계산하여 가뭄전망에 사용되고 있다.

• 한국노년학
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• v.40 no.4
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• pp.639-657
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• 2020

The purpose of this study is to analyze the effect of individual differences in recognition of retirement responsibility on financial preparedness for retirement and to examine moderating effect of income-level on the relationships between the two variables, using the 7th Korean Retirement and Income Study(KReIS). Two research methods, descriptive analysis and hierarchical multiple logistic regression(HMLR) analysis, have been conducted. The total number of sample was 3,869 subjects with an average age of 58.9 years and 55.3% males. The results show that only 35.8% of the respondents make financial plans for retirement, and 64.2% did not. Main findings are as follows. First, 65% of respondents take a responsibility for financial preparedness for retirement, compared to 37% in European countries. Second, people with responsibility for their own retirement are more likely to have a financial preparation for retirement than people who think others(family, society, government) have to take a responsibility for retirement instead of them. Third, there is a significant moderating effect of income-level on relationships between recognition of retirement responsibility and financial preparedness for retirement. As income level decreases, the moderating effect reduces the positive effect of recognition of retirement responsibility on financial preparedness for retirement and vice versa. Fourth, as income level increases and educational level is higher, the tendency to prepare financially for retirement is also increasing. Low-income and low-educated people are less likely to have a financial preparation for retirement than their counterparts. The findings suggest that it is necessary to design an effective incentive scheme for financial preparedness for retirement for low-income and low-educated people and to develop various policies and services to encourage them to prepare financially for retirement.

• 한국노년학
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• v.39 no.2
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• pp.347-362
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• 2019

This study aimed to investigate the association between social support and the change of depressive symptoms and its difference by gender among Korean Baby Boomer. We used the Korean Longitudinal Study of Aging (KLoSA) 5th (in 2014) and 6th waves (in 2016). Samples were Korean Baby Boomer (born 1955 to 1963) who have spouse and children(N = 1,210). Dependent variable was depressive symptoms and independent variables were four social support variables (spousal relationship satisfaction, parent-child relationship satisfaction, frequency of social contact, and number of participation groups). Interaction variables between social support and gender were also included in the model. Hierarchical regression analysis with the lagged dependent variable was performed. Results showed that the higher the satisfaction of spousal relationship and the satisfaction of parent-child relationship, the less the depressive symptoms increased. All interaction variables were not significant. These findings mean that the support from the spouse and the child is helpful in lowering depressive symptoms, and the associations between social support and depressive symptoms are not different by gender among Baby Boomer. It implies that interventions for enhancing family relationships, especially spousal relationship and parent-child relationship, may be useful to reduce depressive symptoms among Korean Baby Boomer.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.95-102
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• 2023

This study aims to empirically verify the moderating effect of population drop on the relationship between demographic changes and crime decline in local cities facing population decline in Korea. The study employs changes in the population of young adults, men, elderly, foreign residents, and population movement as factors of demographic changes, including types of the city as a control variable in the research model. The rate of change in population drop is used as a moderator variable and the rate of change in crime decline as a dependent variable. Data are collected from 155 cities with declining populations from 2010 to 2022 through KOSIS, the National Statistics Portal, and information disclosure requests. Data collected are analyzed using moderated regression analysis. In the first and second stages of the analysis, they show that changes in the population of young adults, population movement, foreign people, population drop, and the type of city affect the change in crime. Moderated regression analysis shows that only the interaction terms among changes in the population of young adults, changes in population movement, and changes in the population of foreigners and the population drop affects change in crime significantly.

• Journal of Industrial Convergence
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• v.20 no.9
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• pp.91-98
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• 2022

This study was conducted to investigate the effect on subjective well-being and depression of the elderly with chronic diseases. Using data from the 15th Korea Welfare Panel in 2020, 3,910 people who responded that they had chronic diseases over the age of 65 were analyzed with stepwise regressions. As a result, the factors affecting the subjective well-being of the elderly with chronic diseases were in the order of satisfaction with leisure life, subjective health status, satisfaction with children relationship, satisfaction with family income, satisfaction with spouse. The explanatory power of this model was 32.0% (F=351.44 p<.001). And also, factors affecting depression were in order of subjective health status, satisfaction with spouse, satisfaction with social relationship, satisfaction with children relationship, satisfaction with leisure life, and satisfaction with family income. The explanatory power of this model was 21.4% (F=178.59, p<.001). Therefore, policy systems to support leisure life of the elderly with chronic disease and measures to induce participation in programs using community resources are needed. And health management programs and institutional support to improve subjective health status are also needed. In addition, it is expected that economic support at the national policy level and various program execution strategies and support personnel will be secured at the community level.

• The Journal of Bigdata
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• v.5 no.2
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• pp.1-15
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• 2020

The duty-free industry before COVID-19 has continuously grown since 2000, along with the increase of demand in tourism industry. To cope with the increased demand, the duty free companies have kept the strategies which focused on the sales volume. Therefore, they have developed the ways to increase the volume and capacity, not the efficient operations. In the most of previous research, however, authors have proposed the better strategies for marketing and supporting policies. It is very hard to find the previous research which dealt with the operations like logistics and inventory management. Therefore, in this study, it has been predicted the future demand of frequently purchased items in airport duty free shops based on the estimated number of departing passengers by the linear regression, which concluded with the appropriate inventory level. In addition, it has been analyzed the expected effects by introducing the inventory management policy considering the cost and efficiency of operations. Based on the results of this study, it may be possible to reduce total cost and improve productivity by predicting the excessive inventory problems at duty-free shops and improving cycles of supplying items.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.729-738
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• 2021

Feedback flow control using an artificial neural network was numerically investigated for NACA0015 Airfoil to suppress flow separation on an airfoil. In order to achieve goal of flow control which is aimed to reduce the size of separation on the airfoil, Blowing&Suction actuator was implemented near the separation point. In the system modeling step, the proper orthogonal decomposition was applied to the pressure field. Then, some POD modes that are necessary for flow control are extracted to analyze the unsteady characteristics. NARX neural network based on decomposed modes are trained to represent the flow dynamics and finally operated in the feedback control loop. Predicted control signal was numerically applied on CFD simulation so that control effect was analyzed through comparing the characteristic of aerodynamic force and spatial modes depending on the presence of the control. The feedback control showed effectiveness in pressure drag reduction up to 29%. Numerical results confirm that the effect is due to dramatic pressure recovery around the trailing edge of the airfoil.

• Journal of Hospice and Palliative Care
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• v.17 no.2
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• pp.75-84
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• 2014

Purpose: This study was conducted to explore predictors of health status of family caregivers of hospice patients. Methods: This study included 118 family caregivers of patients who were admitted to the hospice ward of three general hospitals in D city. The collected data were analyzed by frequency, percentage, t-test, one-way ANOVA, Pearson's correlation coefficients, and stepwise multiple regression using the SPSS WIN 18.0 program. Results: The mean score for overall health of family caregivers was 2.68 (${\pm}0.42$). Mean scores for variables related to health were 2.55 (${\pm}0.37$) for sleep quality, 1.91 (${\pm}0.41$) for anxiety and 2.78 (${\pm}0.33$) for hope. Variables such as sleep quality, gender, anxiety and hope explained 59.8% of variance among family caregivers' health conditions. Conclusion: These results suggest the need for nurses to search for ways to promote health of hospice patients' family caregivers, such as improving the quality of sleep, easing their anxiety and encouraging hope.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.260-268
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• 2016

The objective of this study was to investigate the relationship among the variables and effects of depression and physical activity on fatigue in the elderly with chronic disease. A descriptive research design was employed in this study. In total, 500 elderly patients diagnosed with chronic disease were selected from 3 medical centers for the study. The measurements were used to examine their general characteristics, fatigue, depression, and physical activity. To analyze the data, statistical analyses, including ANOVA, t-test, Scheffe's test, Pearson's correlation coefficient, and hierarchical regression analysis, were conducted for the analysis of the data. The results indicated that the age, gender, and educational level in the first step model explained 6% of the effect on fatigue among the elderly with chronic disease. In addition, depression and physical activity in the second step model explained 16% of the effect on fatigue. These findings demonstrate the significance of (considering) depression and physical activity related to care plans when developing health-programs for decreasing fatigue and planning intervention strategies.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.205-216
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• 2021

This study aims to discuss ways needed to prepare their careers through relations between the personal internal factors perceived by college students in the process of career preparation and the external factors they experience during college life. To this end, the study conducted not only a questionnaire survey of 927 students at K University in Seoul but also hierarchical multiple regression analysis, independent two sample t-test, and one-way ANOVA (analysis of variance). The study set career preparation as a dependent variable, presented research models in four steps, and the explanatory power of each model was statistically significant. According to the findings of the study, both Model 1 and Model 2, gender had a significant impact on career preparation. Also, when self-directedness was added to Model 2, self-directedness had a greater impact on career preparation than gender did. When satisfaction with extracurricular activities was added to Model 3, this factor turned out to be helpful for career preparation. When college immersion, or a sense of belonging to college, was added to Model 4, the higher the sense of belonging students perceived, the more helpful they felt it for their career preparations. This study is expected to be helpful in preparing a policy to support college students' career preparation by grasping the relations between the personal characteristics of college students and career-related activities and college immersion they experience during college life.