• 한국인구학
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• 제33권1호
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• pp.1-25
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• 2010

본 글은 여성과 남성의 이동행동 차이 뿐 아니라 여성의 가족 내에서의 성역할과 경제활동 배경에 따라 여성집단 내부에서 이동행동에 어떠한 차이가 있는지 살펴보고, 이러한 차이가 그들의 사회활동참여나 활동공간 등에 대해 가지는 함의를 살펴보고자 하였다. 분석 자료는 통계청의 2004년 "생활시간조사" 원자료(raw data)로 시간량 데이터와 시간대 데이터를 이용하였으며 분석대상은 20세 이상 59세 이하의 서울시민이다. 분석결과 여성의 이동행동 특성은 남녀의 차이가 나타나는 부분도 있고, 또한 여성집단 내에서 혼인지위, 미취학아동의 유무, 경제활동상태, 소득수준 등과 관련하여 성별 차이보다도 더 큰 여성집단 내부의 차이를 가지는 경우도 있었다. 즉 여성의 이동시간량은 남성보다 적고, 남성은 유급노동관련 이동시간량이 그리고 여성은 무급노동관련 이동시간량이 많으며, 여성은 남성보다도 낮 시간대에 주로 이동행동이 발생하고 버스 지하철, 보도 등 대중교통수단을 이용한 이동시간량과 이동행위자비율이 높았다. 반면 미혼여성은 남성보다도 이동시간량이 많고, 경제활동을 하거나 개인소득수준이 높은 여성들은 시간대별 이동행위자비율, 이동목적별 이동시간량 등에서 남성과 비슷한 이동행동 특성을 보여 혼인경험자나 미취학자녀가 있어 성역할 부담이 부과되는 지위에 있는 여성과 많은 차이를 가지고 있었다.

• Human Ecology Research
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• 제55권5호
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• pp.465-480
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• 2017

This study examined the relationship between family meal time and emotional well-being for 5,186 fathers who were employed and had at least one child aged under 18 for the years 2009 and 2014 by analyzing their time diaries. In doing so, changes in time spent by fathers on family meals between 2009 and 2014 were also examined along with the factors associated with the amount of meal time for each year in order to understand ways to increase paternal participation in family meals. Analytic results showed that a father's family meal time had a positive association with his time use and life satisfaction; however, fathers who spent more than 40 minutes a day having meals with the family reported the highest score in time use and life satisfaction. The amount of time fathers spent on family meals increased from 38 minutes in 2009 to 43 minutes in 2014, whose change turned out to be mainly attributable to something more than the compositional change in the population between the two years, such as growing public awareness or cultural acceptance of the value of family meal. Fathers in dual-earner households tend to have longer family meal times; however, different factors were associated with their family meal times in 2009 and 2014. Policy implications are discussed in light of the government-initiated dining table education campaign to increase family meal time for the sake of children's character education at home.

• 한국조사연구학회지:조사연구
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• 제7권2호
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• pp.39-52
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• 2006

우리나라 대다수 조사전문기관은 지역 성 나이대 할당표본추출에 의한 전화조사를 하고 있다. 그러나 평일에는 인구사회적 속성에 따른 개인별 재택률의 차이가 심하므로 체계적 응답자선택편향(respondent selection bias)이 우려된다. 문제 해결을 위해 조사시간대를 할당변수로 추가한 '시간균형할당표본추출'(time-balanced quota sampling) 방법과 저녁시간대 할당을 부분적으로 완화한 '시간균형준할당표본추출'(time-balanced quasi-quota sampling) 방법을 제안한다. 그리고 우리나라 통계청에서 2004년에 수집한 생활시간조사 원자료를 가상적 모집단으로 설정하여 새로운 할당추출법과 기존할당추출법에 의해 얻는 몬테칼로 표본들을 비교할 것이다.

• 항공우주시스템공학회지
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• 제7권3호
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• pp.51-57
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• 2013

This study describes the Federal Aviation Administration(FAA) certification policy for approving the use of Type II, III, and IV deicing/anti-icing fluids on small category airplanes. These fluids can be characterized as non-Newtonian, pseudo-plastic fluids, also known as "thickened" fluids. Deicing fluids are used before takeoff to remove frost or ice contamination, while anti-icing fluids are used before takeoff to prevent frost or ice contamination from occurring for a period of time(referred to as "holdover time") after application. Thickened deicing/anti-icing fluids can affect airplane performance and handling characteristics and their residue may cause stiff or frozen flight controls. This study also describes an approval process that may be used by type certificate holders and applicants for a type certificate under parts 23 to support operational use of these fluids on their airplanes.

• 아동학회지
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• 제29권4호
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• pp.181-197
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• 2008

A mobile phone usage survey was administered to a nationwide sample of 3,617 adolescents. Major motivations of mobile phone usage were mobility/real-time connection, show off, information acquisition, entertainment, dialogue, schedule management, and advice. Maintenance of social relationship with the peer group was most important in mobile phone use. Motivations influenced mobile phone dependency : show off had the strongest influence on anxiety/paranoia followed by dialogue, entertainment, mobility/real-time connection. Without their phones, fashion-oriented adolescents showed mobile phone dependency and anxiety. Stronger dialogue and entertainment motivations were associated with weaker real time connection motivation and stronger paranoia symptoms. Mobile phone dependent adolescents had lower grades, showed lack of attention, had little dialogue with their parents and showed withdrawal from the peer group.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권3호
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• pp.181-191
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• 2015

Change in labor time is affecting occupational safety and health. Recently reduction in labor time brought innovational operation method, investment in plant and equipment, and flexible labor time in some companies, thereby affecting working conditions for labourers. However, working conditions for some vulnerable social groups have deteriorated. As a result, they are becoming more exposed to risk factors such as injury and emotional stress. In this study we use 2014 KWCS data in order to find the social and demographic characteristics in Korean working conditions. To this end, we use exploratory data analysis approach to find the relationship between some of the important variables in the KWCS data. We also use Press-State-Response model to find which group of people are vulnerable to Press and State. We find that women, people over age 50 and business owners are more vulnerable to Press and State than men, people below age 50 and wage workers.

• Kyungpook Mathematical Journal
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• 제64권2호
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• pp.353-369
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• 2024

In this study, we investigate the unknown time-dependent heat source function in inverse problems. We consider three general nonlocal conditions; two classical boundary conditions and one nonlocal over-determination, condition, these genereate six different cases. The finite integration method (FIM), based on numerical integration, has been adapted to solve PDEs, and we use it to discretize the spatial domain; we use backward differences for the time variable. Since the inverse problem is ill-posed with instability, we apply regularization to reduce the instability. We use the first-order Tikhonov's regularization together with the minimization process to solve the inverse source problem. Test examples in all six cases are presented in order to illustrate the accuracy and stability of the numerical solutions.

• 지역사회간호학회지
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• 제26권2호
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• pp.169-177
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• 2015

Purpose: Previous studies focused on the negative effects of Internet use such as obesity, depression, and addiction. However, few studies investigated whether the Internet use for an appropriate time has positive effects on adolescents' health. Thus, the purpose of the study was to examine the dose-response relationship between Internet use for non-academic purposes (NAP) and happiness/stress in adolescents. Methods: This study used data from the 2013 Korea Youth Risk Behavior Web-Based Survey. A total of 72,435 adolescents were included. Rao-Scott ${\chi}^2$ and multiple logistic regression were conducted. To test the dose-response relationship, this study examined how happiness/stress changed with increase in the time of Internet use for NAP. Results: After controlling for general characteristics, the odds ratios for being unhappy and stressful were lowest in adolescents using the Internet for NAP for more than 0 hour and less than an hour a day. Interestingly, students who did not use the Internet for NAP had a significantly higher risk of being unhappy/stressful than those using for more than 0 hour and less than an hour a day. Conclusion: Internet use for NAP for more than 0 hour and less than an hour a day has positive effects on happiness/stress in adolescents.

• Nuclear Engineering and Technology
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• 제53권2호
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• pp.399-413
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• 2021

The solution of the time-dependent neutron diffusion equation can be approximated using quasi-static methods that factorise the neutronic flux as the product of a time dependent function times a shape function that depends both on space and time. A generalization of this technique is the updated modal method. This strategy assumes that the neutron flux can be decomposed into a sum of amplitudes multiplied by some shape functions. These functions, known as modes, come from the solution of the eigenvalue problems associated with the static neutron diffusion equation that are being updated along the transient. In previous works, the time step used to update the modes is set to a fixed value and this implies the need of using small time-steps to obtain accurate results and, consequently, a high computational cost. In this work, we propose the use of an adaptive control time-step that reduces automatically the time-step when the algorithm detects large errors and increases this value when it is not necessary to use small steps. Several strategies to compute the modes updating time step are proposed and their performance is tested for different transients in benchmark reactors with rectangular and hexagonal geometry.

• 한국조경학회지
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• 제29권1호
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• pp.92-99
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• 2001

This study analyzed the effects of illumination on psychological accessibility from a view of satisfaction of night use at urban neighborhood park for actual night users. For this, we have classified the effects of illumination as five sampled independent variables from 12 effects of illumination, and tested the relationship with satisfaction of night use of a dependent variable by multiple regression analysis. The results of this study are as follows; 1) The effects of illumination for night use at urban neighborhood park were divided into five factors; (1) direct effect, (2) effect of promoting use, (3) effect of ensuring security, (4) effect of preparing landscape in the night time, and (5) psychological effect. Among independent variables indicating characteristics of effects of each illumination, uneasiness at night use was high. 2) In a multiple regression model, when other conditions were not changed, the value of security of night use (X\ulcorner) had maximumly an affect on the value of dependent. And, the value of danger to meet the depraved(X\ulcorner) had minimally an affect on the value of dependent variable. 3) For the contribution of security of nigh use(X\ulcorner) and brightness of present using space(X$_4$) to satisfaction of night use(Y) of dependent variable, they had a nearly equal effect on that, and showed about 2 times importance compared to familiarity with park(X\ulcorner) and the beauty of park(X\ulcorner). Also, they showed about 7 times contribution to satisfaction of night use compared to danger to meet the depraved(X\ulcorner), which had minimally an affect on the value of dependent variable, as the most important variables. 4) For the effects of illumination on satisfaction of night use, the effect of ensuring security - pursues security of park for the general rather than security for the specific class or subject - and direct effect to offer proper brightness in using space relatively affected on it much compared to psychological effect, effect of preparing landscape in night time, and effect of promoting use. A research on the psychological effects among the variables related to illumination as well as physical circumstances such as the height, location, direction of illumination should be studied.