• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.137-141
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• 2007

우리나라는 지역적 특성상 여름철에 강수량이 편중되어 있어 계절별로 하천유량의 편차가 매우 크게 나타나고 있다. 또한 계속되는 도시화와 산업화로 인하여 하천에서 다양한 형태의 취수와 이용이 이루어지고, 국민들의 수질향상 등에 대한 기대가 커짐에 따라 하천유량에 대한 양적 질적 요구가 증대되고 있다. 이에 효율적인 수자원운영을 위하여 다양한 형태의 수자원확보가 이루어지고 있으며, 이중 가장 대표적인 댐을 이용하여 운영에 따른 하류 하천에서의 유황개선효과에 대해서 유역 장기분포모의 모형 중 하나인 SWAT모형을 밀양강유역에 적용하여 일 유출량 모의를 수행하였다. 모형의 구축은 $2000{\sim}2005$년의 밀양강유역 기상자료를 활용하였으며, 건교부에서 운영하는 Wamis를 이용하여 DEM, 토지이용도, 토양도를 취득하였다. 또한 밀양댐, 운문댐 유입량과 밀양2지점의 측정유량을 이용하여, SWAT의 다양한 매개변수 중 SOL_AWC, ESCO, CH_K등을 수정하여 Calibration을 실시하였으며, 밀양강유역 오염총량지점인 밀양A지점과 밀양B지점의 측정유량을 이용하여 Validation을 실시하였다. 그 결과, 댐의 경우 0.9이상의 선형상관관계를 나타내었으며, 오염총량지점의 경우 0.6이상의 선형상관관계를 나타내어 모형의 적용성이 양호함을 알 수 있었다. 과거 39년간의 강수량자료를 이용, 구축된 모형의 유역모의운영을 통해 밀양강 유역의 밀양댐과 운문댐이 있음으로 해서, 댐이 없는 경우와 비교, 하류 지점별 유황개선에 어느 정도 효과가 있는지 댐의 순기능에 대한 정량적인 분석을 수행하였다. 또한 댐별 방류량을 변동하여 하류 주요지점에 미치는 유황개선효과를 정량화하였다. 마지막으로 댐의 효율을 최대화한 하류확보가능하천유지유량을 월별평균량으로 산정하였다. 이는 향후 오염총량제 기준유량 및 환경용수의 법제화를 통한 하천유지용수의 증가시 비구조적 대책의 공급가능 최대량으로 활용가능할 것으로 사료된다.

• Computational Structural Engineering
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• v.10 no.2
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• pp.189-201
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• 1997

A number of standard type of steel-box pedestrian bridges are constructed in th metropolitan high way or heavy traffic urban area. Although it has the advantage of speedy construction because of its simple structural form and prefabricated erection method, it has been reported that many of these bridges are deteriorated or damaged and thus are in the state such that it would give unsafe and uncomfortable feeling to pedestrians. In the paper, for the realistic assessment of safety and load carrying capacity of deteriorated and/or damaged steel box pedestrian bridges, an interactive non-linear limit state model is formulated based on the von Mises' combined stress yield criterion. It has been demonstrated that the proposed model is effective for the reliability-based safety assessment and load carrying capacity evaluation of steel-box pedestrian bridges. In addition, this study suggests an effective and practical field load test method for pedestrian bridges.

• Journal of Korean Association for Spatial Structures
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• v.8 no.3
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• pp.65-73
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• 2008

The present work deals with subjective assessments to propose the objective parameter related to the subjective attribute of reverberation in the coupled room varied the aperture opening size. A 1/10 scale model was built and used for the measurements and subjective assessments. For the subjective tests, binaural impulse responses(BIRs) were measured using a dummy head and the measured BIRs were convolved with anechoic recorded music for the presentation over the headphones. The results showed that the perceived reverberation was the largest in the aperture opening size 12.5%(1.97% of mail) room surface area)and decreased with increasing the aperture opening size over 25% (3.94% of main room surface area) in the main room coupled with the secondary reverberant room. In the main room coupled with the secondary absorptive room, there was no changes in the perceived reverberation up to the aperture opening size 6.25%(0.99% of main room surface area) and it gradually decreased with increasing the aperture opening site over 12.5%. The objective parameter, T30/T15, showed a very low correlation with the perceived reverberation in the coupled room varied the aperture opening size but showed a high correlation with a new objective parameter, T30/Tbp, proposed by the authors. Because the late part decay energy more rapidly increases with increasing the aperture opening site than the early and middle part decay energy, the LDT/EDT or T3/T1 is a better quantifier to measure double slopes in the coupled room than the T30/T15.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.267-280
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• 2016

The purpose of this study was to examine the effects of adolescent victimization on human rights consciousness and the mediating effects of depression and evaluation on their own human rights among adolescents. A total of 3,662 middle school student data from '2014 Korean Children and Youth Human Rights Survey' were used for the study. This study analysed a hypothesized research model using structural equation modeling. The main findings on structural model are as follows: First, victimization did not have a direct influence on human rights consciousness but had an indirect effect through a mediating role of evaluation on their own human rights. Secondly, victimization were related to human rights consciousness through double mediating paths of depression and evaluation on their own human right. Finally, human rights education, a control variable, had an indirect effect on human rights consciousness through self-evaluation on human rights. The results of this study suggest some implications for practical intervention and further research on the relation between adolescent victimization and human rights consciousness.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.498-510
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• 2021

This study aims to analyze the influence relationship between the level of fringe benefits and relational contract among social workers in the non-profit organization. Under this relationship, we explored the dual mediating effect of perceived superior's support and perceived organizational support. A total of 371 self-administered questionnaires were distributed to social workers in Gwangju, South Korea, and 271 questionnaires (73.0%) were used for study analysis after excluding incomplete and unreliable responses. This study performed structural equation modeling, the results are as follows. Perceived superior's support and perceived organizational support both have a positive (+) influence on relational contract. Furthermore, perceived superior's support and perceived organizational support were found to mediate effect between fringe benefits and relational contract. Therefore, these results contribute to provide academic meaning that the range of future studies by identifying the dual mediated effect of the fringe benefits and social worker 's relational contract.

• Journal of the Korean Society of Child Welfare
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• no.56
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• pp.221-251
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• 2016

The purpose of this study was to examine whether single-parent family status affects children's school adjustment through children's self-care and media exposure. In addition, the study investigated the mediating effects of self-protection and media exposure of children by analyzing whether single-parent family status has effects on school adjustment through self-care and media exposure of children. For this purpose, we used data of 1,916 students in the 4th grade who participated in the 4th year of the Korean Children and Youth Panel Survey (KCYPS). The results of the structural equation modeling showed that single-parent family environment not only had direct effects on the school adjustment, but also had effects on school adjustment through self-care of children. In addition, it was revealed that self-care of children influenced school adjustment through media exposure. One of the covariates, monthly income of households, did not affect the level of children's self-care. This result draws attention to the problems of the structural deficit of single-parent families. Therefore, political measures that correspond to the structural characteristics and special needs of single-parent families, along with their current financial support, are needed to improve the level of school adjustment of children from single-parent families.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.558-576
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• 2020

The purpose of the research was to verify the mediating effect of social support and cognitive emotional regulation strategy when office worker's emotional expressive ambivalence influences on interpersonal stress. A survey was conducted with 422 office workers from August to September of 2018. SPSS, AMOS and Mplus were used for descriptive statistics, correlation analysis, verification of structural equation modeling and mediated effect. There was a partial mediating effect in emotional expressive ambivalence of self-defense model, a complete mediating effect in relational emotional expressive ambivalence model. In both self-defense and relational emotional expressive ambivalence model, double mediation effect of passing through support and cognitive emotional regulation strategy in the relationship between emotional expressive ambivalence and interpersonal stress was significant. This study sought ways to reduce interpersonal stress by increasing the level of perception of social support and using adaptive cognitive emotional control strategies for office workers.

• The Korean Journal of Applied Statistics
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• v.28 no.4
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• pp.663-683
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• 2015

The change of the population pyramid due to low fertility and rapid aging threatens the financial sustainability of National Health Insurance. We construct statistical models for prevalence rates and medical expenses using National Health Insurance Service (NHIS) sample cohort data from 2002-2013. We then project yearly expenditures and income of national health insurance until 2060 that considers various assumptions in regards to future population structure and economic conditions. We adopt a VECM-LC model for prevalence rates and the double exponentially smoothing method for the per capita co-payment of healthcare expense (in which the two models are institution-disease-sex-age specific) to project of national health insurance expenditures. We accommodate various assumptions of economic situations provided by the national assembly and government to produce a financial projection for national health insurance. Two assumptions of dependents ratios are used for the projection of national health insurance income to conduct two future population structures by the two assumptions of aging progresses and various assumptions on economic circumstances as in the expenditure projection. The health care deficit is projected to be 20-30 trillion won by 2030 and 40-70 trillion won by 2060 in 2015 constant price.

• The Journal of Korean Association of Computer Education
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• v.5 no.4
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• pp.1-8
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• 2002

With the development of Internet technology, the construction and spread of network environment increased educational adaption and utilization based on World Wide Web. Learners are educated in the competitive, individual, or collaborative learning structure. Among them, competitive and individual educational methods are criticized for bringing about excessive competition and a lack of cooperation. As a new way of educational method, the interest for the collaborative learning structure was increased. In this perspective, we design and implement a web-based collaborative learning system which is adapted the merit and model of collaboration learning and show that the proposed system improves learning achievement and motivation by experimental study on student groups.

• Geotechnical Engineering
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• v.8 no.3
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• pp.37-50
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• 1992

Liquefaction leads to severe damage to earth structures after an earthquake. In this study, shaking table tests were performed on model waterfront structures as a countermeasure against liquefaction. The waterfront structure was reinforced by a compacted Bone, which was investigated for its effectiveness in protecting the structure from excessive deformation induced by the lateral pressure of liquefied ground. Through the tests . on embankment, double sheet pile wall, and anchor sheet pile wall, good quantitative information on the behavior of flow failure and the extent of reinforcement was obtained. The extent of a compacted zone for the protection of the structure depends on the magnitude of the acceleration during the shaking. The measured deformation was represented in terms of the extent of the compacted zone and the magnitude of the input acceleration.