• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.3
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• pp.201-208
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• 2021

In this paper, the effect on the lateral and torsional behavior of ballastless railway plate girder bridge by the installation of the lower horizontal bracing has been reviewed. First of all, the most efficient lower bracing arrangement has been reviewed by comparing and examining the lateral displacement due to the train load, targeting analysis models with different arrangement types of lower bracing. Next, the research on torsional behavior of plate girder bridge with lower bracing has been conducted. In addition, the torsion constant from FEM analysis results has been compared with the torsion constant of a railroad plate girder bridge with a closed section by substituting the upper and lower horizontal bracing with equivalent thickness. Based on this comparison, the impact on the bridge span length and the cross section area of the lower bracing has been examined. Through this study, the curve graph related to lateral buckling moment and torsional constant ratio is presented and the range of plate girder bridge requiring torsional reinforcement is proposed.

• Land and Housing Review
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• v.13 no.3
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• pp.57-68
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• 2022

This study investigates what influences the 2030 households' intention to utilize housing support policies for the younger generation. Using the logistic regression model, our empirical results show that the 'the recognition of youth housing support projects', 'the housing occupation', 'employment type', 'housing type', and 'age' factors have a significant effect on the intention to use the housing support policies. Specifically, the intention is positively associated with economic activity, one-room residence, monthly rent, employment status during the Covid-19 period, and policy recognition, while negatively related to age. In addition, willingness to use the housing support policies is greater when respondents lived in a studio, lived on a monthly rent, recognized the policy, and improved their employment status. The results suggest that housing support programs need to be expanded and improved. Moreover, information on housing support policies should be efficiently delivered to eligible households, and more sophisticated housing support policies should be provided for young people early in their careers.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.14-25
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• 2009

Development work of apartment houses is a complex medium-and long-term project requiring grand resources and work force. Since in combination inner and outer project variables relate to project output, uncertainties caused by not only a given site condition but also politic, economy and social sectors are generated during the project. These risks influence output of the project as important factors, and ultimately as management variables in priority giving an effect on earnings and the financial structure of enterprises they should be manageable with the risk reduction plan. In this point of view, this study focused on development work of apartment houses among construction project. Risky factors were deduced, analyzed and evaluated based on Value Engineering from planning to designing to executing to maintaining. Eventually, this study showed the foundation guaranteeing competitive power of public and private construction sectors.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.3
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• pp.51-60
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• 2017

School safety in Japan in the 21st century has been directly influenced by changes in school education policy. The purpose of Japanese school education is to nurture self-reliance, cooperation, and creative humanity by promoting 'zest for life'. Reflecting this, the purpose of school safety is to strengthen survival capabilities that students can overcome in any disaster situation. The main features of Japanese school safety are as follows: 1) to emphasize ability to survive; 2) to focus on school safety role in home and community; 3) to balance between school safety and school education; 4) to emphasize school safety education through experiential and active learning; 5) to pursue safer school facilities; 6) to focus on continuous improvement through PDCA(Plan-Do-Check-Act); 7) to spread the UN safe school model. This analysis and discussion on Japanese school safety will give meaningful implications to Korea's school safety which has recently undergone dramatic changes.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.118-118
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• 2021

최근 지구 온난화 현상으로 인한 기후변화로 이상기후 현상이 발생하고 있으며 이로 인해 장기적으로 폭염의 빈도 및 강도 상승에 따른 가뭄 피해 우려가 증가하고 있다. 농업 가뭄은 강수량 부족, 토양 수분 부족, 저수량 부족 등 농업분야에 영향을 주는 인자들과 관련되어 있어 농작물 생육 및 수확량 감소를 야기한다. 우리나라는 논농사가 주를 이루고 있어 국내 농업 가뭄은 주수원공인 농업용 저수지의 가용저수용량으로 판단 가능하다. 따라서 안정적인 농업용수 공급을 위해 수리시설물의 모니터링, 공급량 등의 분석이 이루어져야 하며, 농업 가뭄에 대비하기 위해 농업용 저수지의 가용저수용량 파악이 필요하다. 수자원 분야에서 지점자료의 시·공간적 한계점을 보완하기 위해 인공위성 자료를 활용한 연구가 활발히 이루어지고 있으며, 본 연구에서는 위성영상 자료 및 딥러닝 기반 알고리즘을 적용하여 농업용 저수지 수표면 탐지 및 시계열 분석을 목적으로 한다. 위성영상 자료는 5일 주기 및 10 m 공간해상도를 가진 Sentinel-2 위성영상 자료를 활용하고자 하였으며, 딥러닝에 적용하기 위하여 100장 이상의 영상 이미지를 구축하였다. 딥러닝 기반 알고리즘으로는 Convolutional Neural Network (CNN)을 활용하였으며, CNN은 주로 이미지 분류나 객체 검출 문제를 해결하기 위해 제안된 모델로 최근 픽셀 단위로 분류가 가능한 알고리즘이 개발되어 높은 정확도의 수표면 탐지가 가능할 것으로 판단된다. 따라서 본 연구에서는 CNN 기반 수표면 탐지 알고리즘을 개발하여 Sentinel-2 영상 기준 경기도 안성시를 대상으로 소규모 농업용 저수지의 수표면적에 대한 시계열 데이터를 분석하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.380-390
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• 2020

Cyber-university has a higher rate of dropout freshmen due to various educational factors, such as social background, economic factors, IT knowledge, and IT utilization ability than students in twenty offline-based university. These students require a different dropout prevention method and improvement method than offline-based universities. This study examined the main factors affecting dropout during the first semester of 2017 and 2018 A Cyber University. This included management and counseling factors by the 'Decision Tree Analysis Model'. The Management and counseling factors were presented as a decision-making method and weekly methods. As a result, a 'Dropout Improvement Model' was implemented and applied to cyber-university freshmen in the first semester of 2019. The dropout-rate in freshmen applying the 'Dropout Improvement Model' decreased by 4.2%, and the learning-persistence rate increased by 11.4%. This study applied a questionnaire survey, and the cyber-university students LMS (Learning Management System) learning results were analyzed objectively. On the other hand, the students' learning results were analyzed quantitatively, but qualitative analysis was not reflected. Nevertheless, further study is necessary. The 'Dropout Improvement Model' of this study will be applied to help improve the dropout rate and learning persistence rate of cyber-university.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.1
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• pp.33-46
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• 2019

Even though Korea is strengthening the support for startups due to the limitations of growth policies focusing on large companies, the survival rate of startups is very low, so that there should be more efforts to increase the survival rate of startups. As the existing startup support institutions have provided only fragmentary supports to startups, it would be necessary to have the comprehensive support institutions. As an alternative, the accelerator providing the comprehensive support such as spatial support, education, mentoring, networking, seed investment, and connection for follow-up investment to the initial startups was legalized in Korea of 2016, based on the registration system. Currently, within less than two year from then, there have been much interest in it enough to have about 136 registered accelerators. In the United States, the accelerator was introduced more than ten years ago. In Korea, however, it is still in the initial stage, so that the researches or social consensus on the accelerator are not sufficient. Thus, this study aims to suggest the measures for the development of accelerator and the consensus on the decision making for the selection of accelerator of startups, by researching which parts are considered when startups in the accelerator stage select the accelerator. As a result of the empirical analysis, the factor that has the greatest influence on decision making factors when startup chooses an accelerator was the subsequent investment attraction. This can be explained to the accelerator as desired, considering the factor that the startup of the initial stage places the most importance on growth as investment. We hope that these research results will be sustainable in future research related to accelerators, in hopes that it will be useful for establishing accelerator policies for domestic startups and direction for revitalizing related industries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.43-45
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• 2021

The short-term quantitative precipitation prediction (QPF) system is important socially and economically to prevent damage from severe weather. Recently, many studies for short-term QPF model applying the Deep Neural Network (DNN) has been conducted. These studies require the sophisticated pre-processing because the mistreatment of various and vast meteorological data sets leads to lower performance of QPF. Especially, for more accurate prediction of the non-linear trends in precipitation, the dataset needs to be carefully handled based on the physical and dynamical understands the data. Thereby, this paper proposes the following approaches: i) refining and combining major factors (weather radar, terrain, air temperature, and so on) related to precipitation development in order to construct training data for pattern analysis of precipitation; ii) producing predicted precipitation fields based on Convolutional with ConvLSTM. The proposed algorithm was evaluated by rainfall events in 2020. It is outperformed in the magnitude and strength of precipitation, and clearly predicted non-linear pattern of precipitation. The algorithm can be useful as a forecasting tool for preventing severe weather.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.11-19
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• 2014

This study is analyze future climate and land cover change affects behaviors for amount of streamflow and sediment discharge within basin. We used the climate forecast data in RCP 4.5 and 8.5 (2011-2100) which is opposite view for each other among RCP scenarios that are discussed for 5th report for IPCC. Land cover map built based on a social economic storyline in RCP 4.5/8.5 using Logistic Regression model. In this study we set three scenarios: one scenario for climate change only, one for land cover change only, one for Last both climate change and land cover change. It simulated amount of streamflow and sediment discharge and the result showed a very definite change in the seasonal variation both of them. For climate change, spring and winter increased the amount of streamflow while summer and fall decreased them. Sediment showed the same pattern of change steamflow. Land cover change increases the amount of streamflow while it decreases the amount of sediment discharge, which is believed to be caused by increase of impervious Surface due to urbanization. Although land cover change less affects the amount of streamflow than climate change, it may maximize problems related to the amount of streamflow caused by climate change. Therefore, it's required to address potential influence from climate change for effective water resource management and prepare suitable measurement for water resource.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.3
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• pp.346-354
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• 2021

Since 2015, Blockchain has experienced rapid development throughout the world, institutions including Central Banks, Government Departments, Commercial Banks, IT Giants are all accelerating their exploration on Blockchain, and investment on Blockchain related R&D departments and start-up companies also shows explosive growth. This paper studies the impact of blockchain technology on banks' conventional trade settlement methods and describes blockchain technology in term of its concepts, advantages, and disadvantages. It also studies the application processes of blockchain technology combined with conventional trade settlement methods (remittance, collection, and L/C), and analyzes the positive and negative impacts of blockchain technology on the conventional trade settlement methods. In addition, this paper lists the blockchain application cases, analyzes the technology development status and existing problems, and puts forward suggestions and measures for the development of blockchain finance in China based on the case analysis and impact research.