• Computers and Concrete
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• 제11권5호
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• pp.383-397
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• 2013

Two-dimensional tensile stresses are occurring at the back of the anchorage of the tendons of prestressed concrete bridges. A new method named "tensile stress region" for the design of the reinforcement is presented in this paper. The basic idea of this approach is the division of an anchor block into several slices, which are described by the tensile stress region. The orthogonal reinforcing wire mesh can be designed in each slice to resist the tensile stresses. Additionally the sum of the depth of every slice defined by the tensile stress region is used to control the required length of the longitudinal reinforcement bars. An example for the reinforcement design of an anchorage block of an external prestressed concrete bridge is analyzed by means of the new presented method and a finite element model is established to compare the results. Furthermore the influence of the transverse and vertical prestressing on the ordinary reinforcement design is taken into account. The results show that the amount of reinforcement bars at the anchorage block is influenced by the layout of the transverse and the vertical prestressing tendons. Using the "tensile stress region" method, the ordinary reinforcement bars can be designed more precisely compared to the design codes, and arranged according to the stress state in every slice.

• 한국강구조학회 논문집
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• 제19권6호
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• pp.559-573
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• 2007

강바닥판 교량은 비교적 얇은 강판을 서로 용접에 의해 연결한 구조물로서 많은 양의 용접을 피할 수 없다. 강바닥판의 횡리브 복부판에서는 전단력과 비틀림 모멘트가 작용하는 동시에 종리브의 비틀림으로 인한 면내 면외 변형이 작용하기 때문에 종리브-횡리브 복부판-데크플레이트 교차부 및 횡리브복부판 컷아웃(슬릿)부에서 응력집중 현상이 두드러지게 발생하게 된다. 본 연구에서는 강바닥판 구조형식의 피로성능 향상 효과가 큰 교차부에 스캘럽을 두지 않는 동시에 종리브 내부에 횡리브 복부판면과 일치되게 다이아프램을 설치하면 컷아웃부 및 교차부에서의 응력집중 감소효과가 크며, 특히 다이아프램의 설치가 컷아웃부에서의 응력집중 감소효과에 큰 영향을 미치고 있는 연구결과를 바탕으로 다이아프램 상하부면 곡률반경을 대상으로 매개변수해석을 수행한 결과 피로성능에 영향이 큰 응력집중 감소효과가 큰 최적 다이아프램형상을 도출하였다. 또한 최적 다이아프램 형상을 바탕으로 피로성능 향상에 유리한 다이아프램 최적 설치위치를 도출하였다.

• 한국심리학회지 : 문화 및 사회문제
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• 제27권4호
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• pp.629-659
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• 2021

본 연구는 코로나 19 팬데믹 시기동안 한국인이 겪는 정서적 디스트레스에 영향을 미치는 심리·사회적 요인의 영향력을 서로 다른 두 시점에서 비교하였다. 1차 조사시기는 WHO에서 코로나 19 팬데믹을 선언하고, 대구 경북지역이 특별재난지역으로 선정되었던 2020년 4월 13일부터 4월 21일까지이며, 연구참여자 600명의 자료를 수집하였다. 2차 조사시기는 전 세계적으로 코로나 19가 재확산되고, 수도권에서 처음으로 집단감염이 확산되면서 일주일동안 수도권에서만 확진자가 1,000명이 넘었던 시점인 2020년 8월 21일부터 9월 2일까지 진행되었다. 1차 조사의 연구참여자 중 482명이 2차 조사에 응하였으며, 모든 자료는 온라인 설문을 통해 수집되었다. 본 연구는 시점별로 개인특성요인, 코로나 19에 대한 두려움과 사회활동 제약요인, 대인관계갈등 및 수입감소 요인이 코로나 19로 인한 디스트레스(스트레스, 우울, 불안, 분노) 경험에 미치는 영향을 알아보기 위해 위계적 회귀분석을 실시하였다. 그 결과, 두시점 모두에서 정서적 디스트레스에 영향을 미치는 요인으로는 성별, 삶의 질, '코로나 19 관련 정보 수시 확인', '코로나 19 이후 삶을 예측할 수 없어 두려움', '병원 이용의 어려움'이 확인되었다. 시점1에서만 유의한 변인으로 '공적일정에 차질', 시점 2에서만 유의한 변인으로는 연령, 감염취약성, '개인일정에 차질'이 확인되었다. 이를 토대로 논의 및 시사점이 제시되었다.

• 한국심리학회지 : 문화 및 사회문제
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• 제29권2호
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• pp.223-252
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• 2023

본 연구에서는 코로나 대유행 시기에 지각된 스트레스가 심리적 디스트레스(부정정서, 우울, 불안, 분노)에 미치는 영향에서 대처전략의 종단매개효과를 확인하고자 하였다. 또한 코로나 대유행 상황에서 각 연령별로 대처전략의 사용에 차이가 있었는지 살펴보았다. 이를 위해 8개월의 간격을 두고 두 번에 걸쳐 수집된 성인 941명의 두 시점 종단 자료를 활용하였다. 분석결과, 코로나 스트레스(시점1)는 심리적 디스트레스(시점2) 중 우울을 제외한 부정정서, 불안, 분노에 종단으로 영향을 끼치는 것으로 확인되었다. 종단매개효과 분석결과, 대처전략 중 부적응적 대처전략만(시점2)이 코로나 스트레스(시점1)와 심리적 디스트레스(시점2)의 관계에서 종단매개효과를 보이는 것으로 나타났다. 연령별 다집단 분석결과, 대처전략의 사용에 있어서 연령별 차이는 없는 것으로 나타났다. 본 연구는 코로나 대유행 상황에서 일반 성인의 심리적 디스트레스를 종단으로 살펴보았다는 점에서 의의를 지닌다. 마지막으로 본 연구의 한계점과 추후 연구를 위한 제언을 제시하였다.

• 대한조선학회논문집
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• 제28권1호
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• pp.139-149
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• 1991

본연구에서는 이상화구조요소법(理想化構造要素法)을 적용하여 선체구조(船體構造)의 최종(最終) 종강도(縱强度)를 효율적으로 해석할 수 있는 방법을 개발하였다. 이를 위해 2축방향 축력을 받는 판요소(板要素)에 대한 이상화판요소(理想化板要素)를 초기처짐과 잔류응력의 영향 및 국부구조와 전체구조간의 상관효과를 고려하여 정식화하였다. 본 해석법을 이중선각구조(二重船殼構造)로 된 4만톤급 정유운반선(精油運搬船)에 적용하여 초기처짐, 잔류응력 및 재료의 항복응력의 변화에 따른 선각(船殼)거어더의 최종(最終) 종강도(縱强度)를 해석하고, 이들 결과를 바탕으로 종강도(縱强度)측면에서의 잉여강도계수(剩餘强度係數) 및 신뢰성지표(信賴性指標)를 평가하였다.

• 가정과삶의질연구
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• 제31권3호
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• pp.81-92
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• 2013

The purpose of this study is to identify difference in motivation of move to senior cohousing communities in Sweden during 10 years between the year of 2001 and 2010 by a longitudinal study. Questionnaire survey was used for the study. 313 data were collected from 12 senior cohousing communities, which were established by residents-initiated process. It includes 8 of Senior g${\aa}$rden cohousings in 2001 and 4 of +40 cohousings in 2010 nationwide in Sweden. The result indicates that there are significant differences in motivation of move to senior cohousing between 2001 and 2010. Comparing motivation of move to senior cohousing during 10 years, respondents of 2010 focus more on social merits than practical merits of cohousing as they move to cohousing communities. They stress more to the reasons as good contacts with neighbors, mutual supports, sharing common activities and getting rid of loneliness rather than burden of housing and garden management, and universal-designed house. The result of this study reveals motivation of move to senior cohousing has been changed during 10 years in Sweden.

• 한국도로학회논문집
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• 제18권2호
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• pp.43-49
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• 2016

PURPOSES : The field application and performance of continuously reinforced concrete pavement (CRCP), constructed by using the mechanical tube-feeding method, are evaluated in this study. METHODS: The location of the rebar was evaluated by using the MIRA system. The early-age CRCP performance was evaluated via visual survey, in which the crack spacing and crack width were examined. RESULTS: The location of longitudinal reinforcing bars was evaluated via MIRA testing and the results showed that the longitudinal rebars all lie within a given tolerance limit (${\pm}2.5cm$) of the target elevation. In addition, owing to the low temperature when the concrete was pured, the crack spacing in the Dae-Gu direction is slightly wider than that of the Gwang-Ju direction. Almost all of the crack spacings lay within the range of 1.0 m~3.0 m. A crack width of <0.3 mm was measured at the pavement surface. However, as revealed by the field survey, the crack spacing was not correlated with the crack width. CONCLUSIONS : In CRCP constructed by using the mechanical tube-feeding method, almost all of the longitudinal reinforcing bars lay within the tolerance limit (2.5 cm) of the target elevation. The concrete-placing temperature affects the crack spacing, owing to variations in the zero-stress temperature. Crack survey results show that there is no correlation between the crack spacing and crack width in CRCP.

• 보건교육건강증진학회지
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• 제31권3호
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• pp.51-61
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• 2014

Objectives: The purpose of this study was to identify the effects of job characteristics on smoking, and the mediating effects of job stress between job characteristics and smoking among elderly workers. Methods: This study employed data from the Korean Longitudinal Study of Ageing, and a total of 778 older workers were used for analysis. Current smoking status, job stress, job characteristics including physical job demands, job demands related to contents, working days, regularity of working hour, satisfaction with income, and sociodemographic factors were analyzed. Descriptive analysis, t-tests, chi-square test, multiple linear regression, and logistic regression were used for analysis. Results: Results showed that physical job demands and regularity of working hours were significant predictors of smoking of elderly workers. The higher level of physical job demands and regular working-hour increased the risk of smoking. Also, physical job demands, job demands related job contents, and income satisfaction directly impacted on job stress. However, job stress did not mediate the relationship between job characteristics and smoking. Conclusions: The findings suggest that smoking interventions for older workers should take into account job characteristics. Implications for practice and future study directions are discussed.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1813-1819
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• 2001

Partial penetration welding Joint defines that groove welds without steel backing, welded from on side, and groove weeds welded from both sides but without back gouging, that is. it has an unwelded portion at the root of the weld. In this study we analysed fur residual stress and displacement distribution on partial penetration welding condition of thick plate metal. For 25.4mm thick plate, theoretical residual stress and displacement analysis by finite element method using ABAQUS was carried out and compared with the experimental result using hole-drilling method. In results of the condition of partial penetration, it appeared that longitudinal stress at welding area was a little difference and transverse stress did not have any effect by partial penetration multi-pass welding. From a point of welding distortion in partial penetration multi-pass welding, it seemed to be better to control root face smaller than 6.35mm.

• Child Health Nursing Research
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• 제28권1호
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• pp.82-90
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• 2022

Purpose: The aim of this study was to examine the relationships among parenting role sharing, parenting stress, happiness, and parenting behavior of mothers with 6-year-old children. Methods: This study used data from the seventh Panel Study of Korean Children, which began collecting longitudinal data on a sample of newborn households nationwide in 2008 and will continue yearly until 2027. The participants were 1,560 mothers of children aged 6 years. We conducted statistical analyses using descriptive statistics, the t-test, analysis of variance, Pearson correlation coefficients, and stepwise multiple regression. Results: The mean age of the mothers was 36.8±3.7 years. The mothers' perceived parenting role sharing (r=.07, p=.007), parenting stress (r=-.54, p<.001), and happiness (r=.38, p<.001) were significantly correlated with warm parenting behavior. Stepwise multiple regression analysis revealed that parenting stress (β=-.47, p<.001), happiness (β=.15, p<.001), and parenting role sharing (β=.11, p<.001) were significant predictors for warm parenting behavior by mothers. Conclusion: It is essential to reduce mothers' stress and increase their positive emotions (happiness). Fathers should actively share parenting roles in raising children to enhance mothers' warm parenting behavior.