• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.1
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• pp.22-31
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• 2008

RT/IMPOST is an effective algorithm that can realize real-time internal metering policy (IMP) using queue information from loop detector and signal control strategies. In this paper, an investigation was made to adopt the IMP methodology within COSMOS environments in terms of communication environment and control time point. Through the analysis of the communication environment of COSMOS and communication and control steps in RT/IMPOST, a set of applicable alternative were developed and evaluated. Then, one of the alternatives was selected, and performance of the alternative was compared with RT/IMPOST system using a simulation technique. Results showed that two techniques produced the similar performance. Therefore, the method suggested in this paper was evaluated as a practically viable alternative.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.75-85
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• 2003

Laboratory model blast and in-situ rock blast tests were conducted to determine blast-induced stress wave propagation characteristics under different explosive types, different loading conditions and different mediums. Dynamic numerical approaches were conducted under the same conditions as experimental tests. Stress magnitudes at mid-point between two blast holes which were detonated simultaneously increased up to two times those of single hole detonation. The rise time of maximum stress in a decoupled charge condition was delayed two times that of a fully charged condition. Dynamic numerical analysis showed almost similar results to blast test results, which verifies the effectiveness of numerical approaches fur optimizing the tunnel blast design. Dynamic numerical analysis was executed to evaluate rock behavior and damage of the contour hole, the sloping hole adjacent to the contour hole in the road tunnel blasting pattern. The rock damage zone of the sloping hole from the numerical analysis was larger than that of the contour hole. Damage in the sloping hole can be reduced by using lower density explosive, by applying decoupled charge, or by increasing distance between the sloping hole and the contour hole.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.929-929
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• 2012

제주도는 연평균 강우량이 1,975mm에 달하는 우리나라 최다우 지역이지만 하천은 주로 한라산 정상을 중심으로 남 북사면 방향으로 급한 경사를 이루며 발달하고 있으며 하천연장은 대부분 15km 내외로 내륙지역의 하천에 비하여 매우 짧은 특성을 보이고 있다. 투수성이 높은 지질학적 특성으로 인하여 집중 호우시 짧은 기간 동안만 유출이 발생하고 평상시 대부분의 하천은 건천의 상태로 유지되고 있다. 향후 기후변화에 의하여 강우량 및 강우강도의 증가로 인한 강우패턴 변화로 집중호우 및 강력한 태풍의 가능성이 지속적으로 증가할 것으로 예측되고 있으나 제주도에서는 기초 수문자료의 확보조차 어려운 실정이며 강우사상에 따른 하천유출 특성 해석 연구는 거의 전무한 실정이다. 본 연구에서는 제주도 도심부에 위치한 화북천 유역을 대상으로 SWAT 모델 및 WMS(HEC-HMS) 모델을 이용하여 장단기 강우에 따른 유출 특성을 해석하고자 한다. 유역 내 수문 기상 자료는 기상청 관할 AWS 및 기상관측지점 자료를 수집하여 사용하였으며 DEM(미국 USGS), 토지피복도(국가수자원 종합정보시스템), 토양통도(농업과학기술원)의 자료를 각각 구축하여 모델의 입력자료로 사용하였다. 또한 제주특별자치도 수자원본부에서 운영하는 화북천 하류지점의 실 관측자료를 이용하여 모델의 결과치를 검 보정 하였으며, 모의결과의 적합성을 판단하기 위하여 상관계수의 제곱( ), 평균 제곱근 오차(RMSE), 모형 효율성계수(ME)를 이용하였다. 모델링 기법을 이용하여 장기간(2008.1.1~2010.12.31) 동안의 유출량을 산정한 결과 2008년에는 전체 유역 평균 강우량 중에서 5.66%가 유출되었으며, 2009년도에는 3.47%, 2010년도에는 8.12%가 유출되었다. 화북천 유역은 단일강우 40~50mm 발생시에도 유출은 발생하지 않으나 선행강우가 발생시에는 20mm의 강우에도 반응을 하고 50mm 이상에서 급격한 유출이 발생하는 특징을 도출하였다. 향후 유역 내의 많은 실측 유출량 관측자료를 구축하고 모델 개선을 통하여 모델링 기법을 적용한다면 보다 정밀한 하천유출량 산정 및 유출특성 해석이 가능할 것으로 판단된다.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.87-97
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• 2008

The traditional trip-based modeling approach has assumed that a trip is generated for a purpose. However, the approach has not considered trips as a set of connected trips nor has it considered trip chaining. The purpose of this study is to identify general characteristics of trip chaining, and to explore relationships between trip purposes and trip chains using multivariate regression models. The data for this study come from the 2006 Seoul household travel diary survey. It is found that simple trip chains are dominant phenomena, and socio-economic characteristics such as occupation, income, age, and gender are closely related to types of trip chains. People aged less than 20, females, or high-income people are more likely to have a higher number of home-based trip chains. In addition, commute and school trips for workers and students respectively tend to be strongly associated with simple trip chains, while shopping and leisure trips for housewives tend to be related to simple trip chains.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.49-57
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• 2010

Today, internet traffic is rapidly increasing by the appearance of a large number of website thru a numerous internet service provider and the introduction of advanced teaching methods like utilizing ICT(Information and Communication Technology) education. At these actualities, it is requested to increase internet bandwidth in the scene of school; however, it is difficult to resolve the request quickly because of the government's budget and technical problems. In this circumstance, this paper proposes a method to raise the efficiency of internet operations with the current bandwidth. In order to achieve the purpose of this paper, the analysis of internet traffic has been done by the traffic currently being used in school, and an internet bandwidth distribution model differ from the existing standpoint is developed with the analyzed result. It can be used to predict the increase in the bandwidth which may be requested at school in the future, and it can support the office of education for appropriate bandwidth allocation at schools and reduction of school budget in telecommunication. Also, it can be adopted as a future oriented reference model for network policy.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.253-267
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• 2011

This study summarizes some important results from the studies on clouds and aerosols, and their effects on climate in the northeast Asia that were made mainly by Korean scientists and some other scientists from around the world. Clouds and aerosols are recognized as one of the most important factors that contributes to uncertainties in climate predictions and therefore become the subject of active research in the western developed countries in recent years. However, the researches on clouds and aerosols are very weakly done in Korea except ground based measurements of aerosol physical, chemical and optical properties. These measurements indicate that aerosol loadings in the northeast Asia are generally much higher than other parts of the world. On the other hand, researches on clouds are few in Korea. Satellite and ground remote sensing, numerical modeling and aircraft in-situ measurements of clouds are highly needed for better assessment of the role of clouds on climate in the northeast Asia.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.379-384
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• 2019

This study is an online survey user experience study. The purpose of this research is user experience research to make use and development of online surveys. In-depth interviews were conducted with 8 native Koreans who were not experienced with Naver and Google, and were surveyed using Peter Morville's Honeycomb model. In addition, we performed evaluation through tasks and think-aloud. Naver is highly useful, usable, desirable and findable, and Google can confirm its superior accessible and flexible. Research has shown that improvements in usability and ease of functioning are needed by reclassifying and moving menu categories. Online survey user experience that has not been studied previously can predict the direction of usability improvement and can help the user side. We hope that this research will improve the usability of online surveys, and will lead to various related research.

• Knowledge Management Research
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• v.20 no.3
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• pp.155-171
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• 2019

In the entertainment industry which has great uncertainty, it is essential to predict public preference first. Thanks to various mass media channels such as cable TV and internet-based streaming services, the reality audition program has been getting big attention every day and it is being used as a new window to new entertainers' debut. This phenomenon means that it is changing from a closed selection process to an open selection process, which delegates selection rights to the public. This is characterized by the popularity of the public being reflected in the selection process. Therefore, this study aims to implement a machine learning model which predicts the winner of , which has recently been popular in South Korea. By doing so, this study is to extend the research method in the cultural industry and to suggest practical implications. We collected the data of winners from the 1st, 2nd, and 3rd seasons of the Produce 101 and implemented the predictive model through the machine learning method with the accumulated data. We tried to develop the best predictive model that can predict winners of by using four machine learning methods such as Random Forest, Decision Tree, Support Vector Machine (SVM), and Neural Network. This study found that the audience voting and the amount of internet news articles on each participant were the main variables for predicting the winner and extended the discussion by analyzing the precision of prediction.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.415-424
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• 2021

The life of studying abroad includes not only school life, but also various areas such as economy, social relationship, and culture, so the level of satisfaction in each area could be differently shown in each individual. Based on this critical mind, this study aims to analyze the satisfaction with life of studying abroad in the multidimensional perspective. To analyze this, a latent class analysis was applied to identify subgroups, and a multinomial logistic regression model was applied to verify factors influencing group classification. The results of the analysis could be summarized into two. First, there were sub-groups showing different satisfaction with life of studying abroad. The sub-groups showed different levels of satisfaction in five areas such as housing, economy, social relationship, study, and culture, which were not discerned in single dimension. Second, the classification of group was complexly influenced by academic factor, psychological/emotional factor, and environmental factor. Especially, the predictive factor had different influences on each sub-factor. Based on such results of this study, this study aims to seek for the practical and policy-level suggestions for improving foreign students' satisfaction with life of studying abroad.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.323-336
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• 2020

This study's aim was to verify the mediating effect of the social withdrawal and the community spirit within path which the perception of the local community predicted the quality of life of adolescence. For verifying the purpose of this study, this study selected a total of 2,000 cases from the Korean Child-Youth Pannel Study(KYPS) as a research target. In this study, Structural Equation Modeling(SEM) of AMOS 18.0 was applied as an analysis method, and sobel test was applied for utilizing the significance of the mediating effect. The research result were as follows through the presented research method. Firstly, this study has proved the effectiveness of the direct path that the perception of the local community predicted the quality of the life of adolescence. Secondary, this study has verified the effectiveness of the indirect path of the social withdrawal and the community spirit. Based on these findings, this study has presented the intervention methods for the quality of the life of adolescence and the suggestion for the future research.