• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.64-68
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• 2011

본 연구에서는 일반 좌표계를 사용함으로써 자유수면이 매시간 변화하는 계산격자를 구성해야하는 문제점을 해결하였고, 또한 유한차분법의 단점인 지형변화의 적용성을 보완할 수 있었다. 자유수면과 동수압을 고려하기 위하여 계산단계를 3단계(정수압 계산단계, 동수압 보정단계, 자유수면 보정단계)로 나누어 해석하였고, 개발된 수치모형을 이용하여 실험값이 존재하는 수중방파제를 지나는 비선형파의 전파문제에 대해 수치모의를 실시하였다. 전반적으로 수치모의에 의한 결과는 실험값과 일치하는 경향을 나타내었다.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.525-534
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• 2019

The purpose of this convergence study was to evaluate the influence of interpersonal problems on sleep quality in college students and to analyze the mediating role of mental health and the moderated mediating role of emotional regulation. This was a cross-sectional study of 307 students at a college in Seoul. The results of hierarchical linear regression showed that interpersonal problems and mental health were statistically significant predictors of sleep quality in college students. A mediation analysis further revealed that students' mental health mediates the relationship between interpersonal problems and sleep quality. Additionally, there was a moderated mediating role of dysfunctional emotional regulation in this process. Our findings suggest that supportive and adaptive cognitive emotional regulation educational programs should be designed based on college students' maladaptive emotional regulation experiences and individual characteristics.

• Therapeutic Science for Rehabilitation
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• v.9 no.2
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• pp.73-86
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• 2020

Objective : The purpose of this study was to examine the effects of depressive symptoms on the relationship between avoidance(brooding, reflection, and behavioral avoidance) and sleep quality. Methods : In total, there were 947 subjects who were assessed using self-reports on three measures: Center for Epidemiological Studies-Depression (CES-D), Ruminative Response Style (RRS), Cognitive-Behavioral Avoidance Scale (CBAS), and Pittsburgh Sleep Quality Assessment (PSQI). Results : First, depressive symptoms fully mediated the relationship between brooding and sleep quality. Second, reflection did not mediate the relationship between brooding and sleep quality, and reflection had no direct effects on depressive symptoms. Third, depressive symptoms partially mediated the relationship between behavioral avoidance and sleep quality. Conclusion : This study was confirmed the pathological characteristics of brooding compare to reflection, and the essential role of behavioral avoidance and depressive symptoms on sleep problems.

• Sleep Medicine and Psychophysiology
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• v.30 no.1
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• pp.22-27
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• 2023

Objectives: The purpose of this study was to develop a screening tool that is simple and easy to use for assessing sleep problems, including hypersomnolence, restless legs syndrome, and insomnia. We also examined the reliability and validity of this tool. Methods: We developed the Sleep Problem Screening Questionnaire (SPSQ), which consists of three sub-sections: insomnia (SPSQi), hypersomnolence (SPSQh), and restless legs syndrome (SPSQr). Subsequently, the participants, consisting of 222 patients with insomnia disorder and 78 healthy individuals, completed both the SPSQ and the comparative scale (Korean version of the Insomnia Severity Index). The analysis was then conducted using this data. Results: The SPSQ demonstrated good convergent and discriminant validity, as well as satisfactory internal consistency. A cutoff score of 6 on the SPSQi was found to be optimal for distinguishing individuals with insomnia. Conclusion: The results of this study suggest that the SPSQ is a reliable and valid tool for screening sleep problems among general adult population. However, there is a limitation as a comparison and validation with scales related to restless legs syndrome and hypersomnolence were not conducted.

• 전기의세계
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• v.10
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• pp.10-18
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• 1963

본 논문은 Laguerre함수의 Fourier변환에 의한 Wiener와 Lee의 회로망구성법을 일반화한 것이다. 즉 Laplace변환을 사용하여 시간영역에서 임의의 과도특성을 나타내는 회로를 구성하는 문제를 복소주파수면상의 직교함수계에 의한 근사문제로 귀착시켰으며 이때 얻어진 근사함수의 물리적실현성을 확인하고 실제구성예를 들었다. 이때 근사함수로는 복소극이 포함되었을 때도 적용할 수 있도록 이론과 방법이 일반화되었다.

• Korean Journal of Occupational Health Nursing
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• v.31 no.1
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• pp.11-21
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• 2022

Purpose: This study aimed to identify the relationship among musculoskeletal problems, sleep problems, and self-rated mental health of home-care workers. Methods: Data were collected from 447 home-care workers spanning three occupation types: life supporters for the elderly, home-visit caregivers, and life supporters for the disabled. Musculoskeletal problems, sleep problems, and self-rated mental health were assessed using structured questionnaires. Factors affecting self-rated mental health were analyzed using multiple regression. SPSS was used to test the mediating effects of sleep problems on musculoskeletal problems and self-rated mental health. Results: Among the general characteristics, the variables that showed significant differences in musculoskeletal problems were monthly income level, caring-related career duration, weekly working hours, and occupation type; and the variable that showed significant differences in self-rated mental health was occupation type. Among the occupation types, supporters for the disabled had the most musculoskeletal problems and the lowest self-rated mental health. Musculoskeletal problems among home-care workers had a direct negative effect on self-rated mental health and indirect negative effects on sleep problems. Conclusion: Measures are needed to reduce the differences in working conditions and health status among the occupation types of home-care workers. Considering the relevance between the health issues of home-care workers, the development of a carefully designed health promotion strategy is required.

• Sleep Medicine and Psychophysiology
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• v.16 no.2
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• pp.85-90
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• 2009

Introduction: There has been an increasing interest in the relationship between sleep and suicidality. In addition, suicidal patients habitually report their sleep problems. Although sleep-related complaints and electroencephalographic changes are generally encountered in psychiatric disorders, sleep complaints such as insomnia, hypersomnia and nightmares are more common in suicidal patients. In current study, we aimed at investigating the relationship between self-reported sleep duration and suicidality in general population. Methods: One thousand general population (male:female=500:500, mean age=$39.6{\pm}11.6$ years, ranged age=20-77 years) completed Center for Epidemiologic Study-Depression (CES-D), Beck Suicide Intent scale (BSI), Spielberger State-Trait Anger Expression Inventory (STAXI), Barratt Impulsiveness Scale (BIS), Morningness-Eveningness Scale (MES) and brief questionnaire of sleep habits. Results: After controlling for age and sex, score of BSI was correlated positively with the score of CES-D, STAXI and BIS on partial correlation analysis ($r_p$=0.251; p<0.001, $r_p$=0.352; p<0.001, and $r_p$=0.175; p<0.001, respectively). In addition, score of BSI was inversely correlated with the score of MES (rp=-0.066; p=0.037). However, score of BSI showed no significant correlation with sleep duration. However, regression analysis revealed that short (<6 hrs) or long (>10 hrs) sleep duration, the family history of psychiatric illness, the score of CES-D, and the score of STAXI predicted higher score of BSI significantly in total subjects (F=17.837, adjusted $R^2$=0.166; p=0.003, p=0.003, p<0.001, and p=0.003, respectively). This model was explained better in depressed subjects with 16 or higher score of CES-D (F=9.920, adjusted $R^2$=0.298). Conclusion: Current result suggested that not only short sleep duration (<6 hrs) but also long sleep duration (>10 hrs) might be related to suicidality.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.97-104
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• 2015

Sleep is not only an essential physiological function, but also serves important roles in promoting growth, maturation, and overall health of humans. There is increasing interest regarding the impact of sleep and its disorders on the regulation of inflammatory processes and end-organ morbidities, particularly in the context of metabolic and cardiovascular diseases (CVD) and their complications. Obstructive sleep apnea syndrome (OSAS) is an increasingly common health problem in children. In the last decade, the emergence of increasing obesity rates has further led to remarkable increases in the prevalence of OSAS, along with more prominent neurocognitive, behavioral, cardiovascular and metabolic morbidities. Although the underlying mechanisms leading to OSAS-induced morbidities are likely multifactorial and remain to be fully elucidated, activation of inflammatory pathways by OSAS has emerged as an important pathophysiological component of the end-organ injury associated with this disorder. To this effect, it would appear that OSAS could be viewed as a chronic, low-grade inflammatory disorder. Furthermore, the concurrent presence of obesity and OSAS poses a theoretically increased risk of OSAS-related complications. In this study, we will critically review the current state of research regarding the impact of insufficient and disrupted sleep and OSAS on the immune processes and inflammatory pathways that underlie childhood OSAS as a distinctive systemic inflammatory condition in children, and will explore potential interactions between OSAS and obesity.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.175-180
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• 1995

산업계를 중심으로 많은 직장에서 교대제 근무가 실시되고 있으나, 교대작업에 관한 작업시간의 단축이 요구되고 있는 실정이다. 교대제근무의 도입에 따라 직장내에서 취하는 수면과 이러한 수면후 아침 일찍 작업을 계속하는 경우도 일반화 되고 있다. 일반적으로, 수면시간은 적어도 7시간 정도 취하는 것이 이상적 이라고 일본 후생성 등에서 권장하고 있지만, 직장에 따라서는 심야 근무의 종료시간등의 문제때문에, 반드시 이러한 수면의 장려시간이 지켜지는 경우는 많지 않다. 따라서, 수면량의 부족 및 그에 따른 수면의 질적 저하가 다음날 작업시에 작업자의 심신반응에 좋지않은 영향을 미치게 될것이라는 것은 쉽게 예상할 수가 있다. 이러한 점을 배경으로, 본 연구는 신경감각작업의 대표적인 예의 하나인 열차운전에 종사하는 운전사을 대상으로 새벽에 하는 작업에 대해 전날밤에 취한 수면의 양.부가 작업시에 작업자의 자각적 피로감에 양향을 미친는 가를 사례적으로 연구하여 분석한 것이다.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.13-21
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• 2014

The paper provides an efficient method for generating water crown animation. Compared to general liquid simulation, water crown animation requires tremendous computational loads. Tackling the problem, we propose a novel geometry based approach with procedural texture. Unreal engine is utilized to construct material and handle the geometric mesh combined with water texture. The experimental results demonstrate our method achieves effective performance for realistic water crown animation.