• 대한가정학회지
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• 제44권7호
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• pp.11-20
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• 2006

This study investigated the purpose of internet usage among high-school seniors and how their psychological, behavioral, and interpersonal adjustment levels were affected by the amount of lime spent on the internet. The subjects were 572 high-school seniors who participated in the first panel of Korean Education Empolyment Panel (KEEP). The participants were divided into 2 groups: low use group using the internet for less than 30 minutes a day and high un group using the internet for more than 3 hours a day. The adjustment levels of these two groups were compared. The findings were as follows. First, the high use group used the internet to enjoy games, whereas the low use group used the internet to seek schoolwork-related information. Second, the high use group had more negative self-concepts and experienced more stress regarding economic hardship than the low use group. Finally, the high use group watched T.V. longer, studied less, and had more experiences of deviant behaviors, such as bullying, smoking, drinking, and sexual relations.

• 한국직업건강간호학회지
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• 제24권2호
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• pp.76-85
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• 2015

Purpose: The purpose of this study was to identify knowledge structure of the Korean Journal of Occupational Health Nursing from 1991 to 2014. Methods: 400 articles between 1991 and 2014 were collected. 1,369 keywords as noun phrases were extracted from articles and standardized for analysis. Co-occurrence matrix was generated via a cosine similarity measure, then the network was analyzed and visualized using PFNet. Also NodeXL was applied to visualize intellectual interchanges among keywords. Results: According to the results of the content analysis and the cluster analysis of author keywords from the Korean Journal of Occupational Health Nursing articles, 7 most important research topics of the journal were 'Workers & Work-related Health Problem', 'Recognition & Preventive Health Behaviors', 'Health Promotion & Quality of Life', 'Occupational Health Nursing & Management', 'Clinical Nursing Environment', 'Caregivers and Social Support', and 'Job Satisfaction, Stress & Performance'. Newly emerging topics for 4-year period units were observed as research trends. Conclusion: Through this study, the knowledge structure of the Korean Journal of Occupational Health Nursing was identified. The network analysis of this study will be useful for identifying the knowledge structure as well as finding general view and current research trends. Furthermore, The results of this study could be utilized to seek the research direction in the Korean Journal of Occupational Health Nursing.

• 지역사회간호학회지
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• 제18권4호
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• pp.651-661
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• 2007

Purpose: This study was performed to identify factors affecting the functional status in disabled persons in the Jeiu Province. Method: Data were collected from 318 disabled persons in the Jeiu province during the period from the 6th of July to the 11th of October in 2006. The functional status was assessed by the disability assessment schedule II (Whodas II) of the World Health Organization and collected data were analyzed using the SAS 8.0 program. Result: The mean score of WHODAS II was 29.9. According to the results of multiple regression, factors affecting the functional status were perceived health condition(t=3.44, p<.001), brain disorder disability(t=2.55, p<.001), treatment status(t=-1.95, p=.05), drinking(t=2.09, p=.04), stress(t=-2.72, p=.01), depression(t=-2.70, p=.01). heart disease(t=2.62. p=.01) and anemia(t=2.20, p=.03). Conclusion: The functional status was affected by health behaviors, diseases, and the type of disability. Thus, future efforts to promote the functional status of disabled persons may need to take into account all these factors.

• 방사성폐기물학회지
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• 제19권3호
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• pp.307-322
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• 2021

This study developed an analytical methodology for the mechanical integrity of spent nuclear fuel (SNF) cladding tubes under external pinch loads during transportation, with reference to the failure mode specified in the relevant guidelines. Special consideration was given to the degraded characteristics of SNF during dry storage, including oxide and hydride contents and orientations. The developed framework reflected a composite cladding model of elastic and plastic analysis approaches and correlation equations related to the mechanical parameters. The established models were employed for modeling the finite elements by coding their physical behaviors. A mechanical integrity evaluation of 14 × 14 PWR SNF was performed using this system. To ensure that the damage criteria met the applicable legal requirements, stress-strain analysis results were separated into elastic and plastic regions with the concept of strain energy, considering both normal and hypothetical accident conditions. Probabilistic procedures using Monte Carlo simulations and reliability evaluations were included. The evaluation results showed no probability of damage under the normal conditions, whereas there were small but considerably low probabilities under accident conditions. These results indicate that the proposed approach is a reliable predictor of SNF mechanical integrity.

• 지역사회간호학회지
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• 제29권4호
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• pp.476-487
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• 2018

Purpose: The present study is focused on understanding weight perception related with individual- and school-level multifactorial origins, underestimated and overestimated respectively, in normal body weight adolescents. Methods: Using the 2017 Korea Youth Risk Behavior Web-based Survey data of 45,902 students from 799 secondary schools, a multilevel multinomial logistic regression analysis was performed where adolescents (level1) were nested within schools (level 2). Results: At the school level, the average school body mass index (BMI, $kg/m^2$) and physical education were associated with weight perception among both boys and girls. In boys, geographic areas were associated with weight underestimation. At the individual level, perceived economic status, weekly allowance, BMI ($kg/m^2$), smartphone usage time (hrs/day) and perceived stress were associated with weight perception among both boys and girls. Age, paternal education, academic achievement and alcohol use were associated with weight perception among girls, while part-time job and physical activity were associated with weight perception among boys. Conclusion: Our findings underscore the importance of individual- and school-level environments in developing correct weight perception and have implications for school health education to establish healthy lifestyle behaviors for all adolescents.

• 한국가시화정보학회지
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• 제17권2호
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• pp.10-16
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• 2019

Considering the role of viscosity in the hemorheology, the characteristics of non-Newtonian fluid are important in the pulsatile blood flows. Stenosis, with an abnormal narrowing of the vessel, contributes to block blood flows to downstream tissue and lead to plaque rupture. Therefore, systematic analysis of blood flow around stenosed vessels is crucial. In this study, non-Newtonian behaviors of blood analog fluids around the micro-stenosis with 60 % severity in diameter of $500{\mu}m$ was examined by using CFX under the pulsatile flow conditions with the period of 10 s. Viscosity information of two non-Newtonian fluids were obtained by fitting the value of normal blood and highly viscous blood. As the Newtonian fluid, the water at room temperature was used. During the pulsatile phase, wall shear stress (WSS) is highly oscillated. In addition, high viscous solution gives rise to increases the variation in the WSS around the micro-stenosis. Highly oscillating WSS enhance increasing tendency of plaque instability or rupture and damage of the tissue layer. These results, related to the influence on the damage to the endothelium or stenotic lesion, may help clinicians understand relevant mechanisms.

• 한국지반공학회논문집
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• 제35권2호
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• pp.19-27
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• 2019

본 논문에서는 테이퍼 말뚝의 좌굴 거동을 평가할 수 있는 해석모델을 제안하였다. 말뚝의 변단면과 주면마찰, 지반의 비균질성을 고려하는 지반-말뚝 시스템의 좌굴을 지배하는 미분방정식을 유도하였다. 이 지배방정식을 Runge-Kutta 법을 이용하여 직접 수치 적분하였고, 미분방정식의 고유치인 좌굴하중은 Regula-Falsi 법을 이용하여 산정하였다. 원통형 말뚝에 대한 문헌값과 이 연구의 좌굴하중을 비교하여 연구의 타당성을 검증하였고, 지반-말뚝에 관련된 무차원변수가 좌굴하중, 좌굴모드, 좌굴응력에 미치는 영향을 분석하였다.

• Steel and Composite Structures
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• 제31권3호
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• pp.291-301
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• 2019

Pure torsion loading conditions were not frequently occurred in practical engineering, but the torsional researches were important since it's the basis of mechanical property researches under complex loading. Then a 3D finite element model with precise material constitutive models was established, and the effectiveness was verified with test data. Parametric studies with varying factors as steel yield strength, concrete strength and sectional height-width ratio, were performed. Internal stress state and the interaction effect between encased steel tube and the core concrete were analyzed. Results indicated that due to the confinement effect between steel tube and core concrete, the torsional strength of CFT columns was greatly improved comparing to plain concrete columns. The steel ratio would greatly influence the torque share between the steel tube and the core concrete. Then the torsional strength calculation formulas for core concrete and the whole CFT column were proposed. The proposed formula could be simpler and easier to use with guaranteed accuracy. Related design codes were more conservative than the proposed formula, but the proposed formula presented more satisfactory agreement with experimental results.

• Journal of the Korean Wood Science and Technology
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• 제32권6호
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• pp.67-73
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• 2004

The influence of liquefied wood (LW) on the mechanical and thermal properties of liquefied wood-polymer composites (LWPC) was investigated in this study. The thermal behaviors of LWPC were characterized by means of thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. LW showed significant effects on the mechanical strength properties. The increase of flexural MOE and Young's modulus was related to the increase of stiffness of LWPC. The effect of LW was also significant on the flexural and tensile MOR. The impact strength decreased with the increase of LW application level. With the increased stress concentration by the poor bonding between LW and polymer, the impact strength of LWPC decreased, compared with that of high-density polyethylene (HDPE). The thermal stability of LWPC decreased with the increase of LW content up to 40%. The melting temperature of HDPE decreased with the increase of LW loading level. Enthalpy of HDPE also decreased with the addition of LW. This study proves the thermal stability necessary for the consolidation of composition materials.

• 한국학교보건학회지
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• 제35권3호
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• pp.92-103
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• 2022

Purpose: The purpose of this study was to prepare basic data for education and policy proposals related to enhancement of happiness by identifying factors affecting the subjective happiness among Korean adolescents by family type. Methods: The study was a secondary analysis using the raw data of the 16th Youth Risk Behavior Web-based Survey (2020). A complex sample multiple logistic regression analysis was conducted to identify factors affecting adolescent happiness by family type. Results: As a result, the factors that commonly affect the subjective happiness of adolescents for all family types were identified as economic status, academic performance, perceived stress, and loneliness. Additional factors that affect the subjective happiness of adolescents of both Korean two-parent and single parent families were sleep and subjective health status. Financial assistance, number of toilets, breakfast, exercise, depression, suicidal ideation, and suicide attempt were also reported for Korean two-parent families. Conclusion: This study provided empirical basic data for enhancing adolescent happiness in consideration of priority targets and family composition characteristics by identifying factors affecting subjective happiness by family type. Adolescent happiness is a factor that should be actively pursued at home, school, and society, and it should be the goal of education for holistic growth of students.