• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.77-77
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• 2016

최근 기후변화로 인한 수문기상학적인 극한 사상들은 점점 대형화되고 있고, 그 발생빈도 또한 잦아지고 있다. 인구의 증가와 급격한 도시화, 자산 가치의 증가 등으로 물과 관련된 재해로 인한 피해는 점점 더 규모가 커지고 있다. 홍수와 가뭄, 허리케인, 쓰나미와 같이 물과 관련된 재해는 그 영향을 받는 사람들의 수로 본다면 지구상의 재해 중 90%를 차지하고 있을 만큼 그 규모가 크다 할 수 있으며, 전세계적으로 물관련 재해로 인한 재산상의 피해를 약 1,000억 달러 규모로 추산하고 있는데, 2030년에는 그 현재의 두 배가 될 것으로 예측하고 있다. 이와 같은 재해로 인한 피해는 개도국이나 최빈국뿐만 아니라 관련 인프라가 잘 구축되어 있는 선진국 또한 예외는 아니다. 2015년 9월 UN 세계지속가능 정상 회의에서 각국의 수반들 또한 17개의 "지속가능개발목표(Sustainable Development Goals; SDGs)"를 채택함으로서 post-2015 아젠다가 세계를 지속가능하고 균형 있게 바꾸어 나가기 위해서 취해야 하는 가장 시급하고 필요한 과감한 혁신적인 조치임을 인식하였다. 재해경감과 지속가능개발은 2005년 채택된 "효고프레임웍(Hyogo Framework for Action) 2005-2015"에서 도 중요하게 다루어 졌다. 2015년 3월 제3차 세계재해경감대회에서 채택된 "센다이 프레임웍(Sendai Framework for Disaster Risk Reduction) 2015-2030"은 Post-2015 개발의제의 첫 번째 합의 결의안이라 할 수 있으며, 인명피해의 실질적인 감소와 재해에 의한 영향으로 피해 보는 사람들의 수를 줄이고, 경제적 손실과 대형 인프라 피해의 경감을 주요 타겟으로 하고 있다. 이와 같은 리질리언스의 중요성은 SDGs의 Goal 11인 "안전하고 지속가능한 도시와 정주지 조성(Make cities and human settlements inclusive, safe, resilient and sustainable)"에서 강조되고 있을 뿐만 아니라 다양한 골에서 재해로 부터의 리질리언스 확보에 대한 필요성을 강조하고 있다. 재해 위험을 경감시키기 위해서 국제적으로, 지역적으로 또는 국경을 넘어서는 협력 관계의 구축이 중앙정부나 지방정부를 비롯한 국가적으로 절대적으로 필요한 노력이라 할 수 있다. 특히나, Post-2015 개발 아젠다에 대한 기후변화와 재해경감을 위한 금융지원을 포함한 최빈국, 개도국, 군소 도서국가들과 중견국 선진국들의 양자간이나 다자간 협력 채널을 통한 역량 강화가 필요하다.

• Smart Structures and Systems
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• v.31 no.4
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• pp.365-381
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• 2023

The existing vision-based techniques for inspection and condition assessment of civil infrastructure are mostly manual and consequently time-consuming, expensive, subjective, and risky. As a viable alternative, researchers in the past resorted to deep learning-based autonomous damage detection algorithms for expedited post-disaster reconnaissance of structures. Although a number of automatic damage detection algorithms have been proposed, the scarcity of labeled training data remains a major concern. To address this issue, this study proposed a semi-supervised learning (SSL) framework based on consistency regularization and cross-supervision. Image data from post-earthquake reconnaissance, that contains cracks, spalling, and exposed rebars are used to evaluate the proposed solution. Experiments are carried out under different data partition protocols, and it is shown that the proposed SSL method can make use of unlabeled images to enhance the segmentation performance when limited amount of ground truth labels are provided. This study also proposes DeepLab-AASPP and modified versions of U-Net++ based on channel-wise attention mechanism to better segment the components and damage areas from images of reinforced concrete buildings. The channel-wise attention mechanism can effectively improve the performance of the network by dynamically scaling the feature maps so that the networks can focus on more informative feature maps in the concatenation layer. The proposed DeepLab-AASPP achieves the best performance on component segmentation and damage state segmentation tasks with mIoU scores of 0.9850 and 0.7032, respectively. For crack, spalling, and rebar segmentation tasks, modified U-Net++ obtains the best performance with Igou scores (excluding the background pixels) of 0.5449, 0.9375, and 0.5018, respectively. The proposed architectures win the second place in IC-SHM2021 competition in all five tasks of Project 2.

• The Journal of Sustainable Design and Educational Environment Research
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• v.17 no.2
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• pp.11-21
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• 2018

This study suggests desirable disaster safety education curriculum through analyzing the operational status of the school disaster safety management training course and demand survey of school staff. First, the problem of the disaster safety training course of the school is not connected with the lack of law and system and the school disaster safety job. Second, improvement of law and system and variety of training should be made to acquire professional knowledge. Third, it is necessary to divide curriculum into the following four categories, according to educational needs of public officials ; Educational administration officers course focused on facility safety, maintenance and disaster countermeasure. Educational officials in technical post course addressing approval and permission of school facility projects, seismic reinforcement of school building, etc. Educational supervisors course covering roles and responsibilities of the school safety supervisors in the event of disaster. Teaching staffs course focused on safety instructions for students. Fourth, it is found that lectures and experiential learning methods are the most desirable methods of teaching and learning, and the major ranks are earthquake disaster, fire, gas, typhoon, school road, and electrical safety.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.640-654
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• 2021

Purpose: Normal education operation was difficult in the national disaster situation of Coronavirus Infection-19. Non-face-to-face education can be an alternative to face to face education, but it is not easy to provide the same level of education. In this study, the professor of disaster management field will identify problems that can occur in the overall operation and progress of non-face-to-face education and seek ways to improve non-face-to-face education. Method: Non-face-to-face real-time education was largely categorized into pre-class, in-class, post-class, and evaluation, and case studies were conducted through the professor's case studies. Result&Conclusion: The results of the survey are as follows: First, pre-class, it was worth considering providing a non-face-to-face educational place for professors, and the need for prior education on non-face-to-face educational equipment and systems was required. In addition, it seems necessary to make sure that education is operated smoothly by giving enough notice on classes and to make efforts to develop non-face-to-face education programs for practical class. Second, communication between professor and learner, and among learners can be an important factor in non-face-to-face mid classes. To this end, it is necessary to actively utilize debate-type classes to lead learners to participate in education and enhance the educational effect through constant interaction. Third, non-face-to-face post classes, policies on the protection of privacy due to video records should be prepared to protect the privacy of professors in advance, and copyright infringement on educational materials should also be considered. In addition, it is necessary to devise various methods for fair and objective evaluation. According to the results of the interview, in the contents, which are components of non-face-to-face education, non-face-to-face education requires detailed plans on the number of students, contents, and curriculum suitable for non-face-to-face education from the design of the education. In the system, it is necessary to give the professor enough time to fully learn and familiarize with the function of the program through pre-education on the program before the professor gives non-face-to-face classes, and to operate the helpdesk, which can thoroughly check the pre-examination before non-face-to-face education and quickly resolve the problem in case of a problem.

• Wind and Structures
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• v.25 no.1
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• pp.79-100
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• 2017

The use of wind energy resources is developing rapidly in recent decades. There is an increasing number of wind farms in high wind-velocity areas such as the Pacific Rim regions. Wind turbine towers are vulnerable to tropical cyclones and tower failures have been reported in an increasing number in these regions. Existing post-disaster failure case studies were mostly performed through forensic investigations and there are few numerical studies that address the collapse mode simulation of wind turbine towers under strong wind loads. In this paper, the wind-induced failure analysis of a conventional 65 m hub high 1.5-MW wind turbine was carried out by means of nonlinear response time-history analyses in a detailed finite element model of the structure. The wind loading was generated based on the wind field parameters adapted from the cyclone boundary layer flow. The analysis results indicate that this particular tower fails due to the formation of a full-section plastic hinge at locations that are consistent with those reported from field investigations, which suggests the validity of the proposed numerical analysis in the assessment of the performance of wind-farms under cyclonic winds. Furthermore, the numerical simulation allows to distinguish different failure stages before the dynamic collapse occurs in the proposed wind turbine tower, opening the door to future research on the control of these intermediate collapse phases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.296-299
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• 2015

Marine disaster, such as 'Dolphin Lake ship', "the Sewol ferry', on the ocean needs emergency communication with land post and Rescue services. It needs of emergency communication system has increased in Republic of Korea peninsula with the sea on three side. The system will be more fully equipped to deal with disasters linked to communication so alone sailing ship is at sea. Research is needed on communication links to submarines operated by submarine to sink a ship, as well as immersion in the sea with. And it is necessary in the study of the land in preparation for the emergency disaster ship and submarine communication links for offshore and subsea oil and associated communication systems. Will be studied in preparation for the communication protocols and emergency and disaster location and land the plane or for a career in the satellite systems are linked through this.

• Structural Engineering and Mechanics
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• v.62 no.4
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• pp.465-475
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• 2017

Photovoltaic (PV) panels are used in high-rise buildings to convert solar energy to electricity. Due to the considerable energy consumption of high-rise buildings, applying PV technology is of great significance to energy saving. In the application of PV panels, one of the most important construction issues is the connection of the PV panel with the main structures. One major difficulty of the connection design is that the PV panel connection consists of two separate components with coupling and indeterminate dimension. In this paper, the gap element is employed in these two separated but coupled components, i.e., hook and catch. Topology optimization is applied to optimize and design the cross-section of the PV panel connection. Pareto optimization is conducted to operate the optimization subject to multiple load scenarios. The initial design for the topology optimization is determined by the common design specified by the Technical Code for Glass Curtain Wall Engineering (JGJ 102-2003). Gravity and wind load scenarios are considered for the optimization and numerical analysis. Post analysis is conducted for the optimal design obtained by the topology optimization due to the manufactory requirements. Generally, compared with the conventional design, the optimized connector reduces material use with improved structural characteristics.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.210-210
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• 2022

This study evaluates Japan's Official Development Assistance (ODA) projects in Thailand from 2011 to 2013 by deploying the Sendai Framework for Disaster Risk Reduction (SFDRR) and the Organization for Economic Cooperation Development (OECD) evaluation criteria. Special attention is placed on disaster-related development assistance activities of Japan through reviewing long-term impacts of the projects. The Japan International Cooperation Agency (JICA) has played a crucial role in transferring Japan's experiences on disaster risk management to developing countries, including Thailand. The study highlights two flood risk management projects in Thailand with the support of JICA after the 2011 floods, namely the Project for the Comprehensive Flood Management Plan for the Chao Phraya River Basin and the Project for Flood Countermeasures for Thailand Agriculture Sector. The case studies demonstrate that the projects were efficiently and effectively conducted for meeting Thailand's needs and requirements. JICA provided multi-hazards risk analysis through scientific data as well as local knowledge. However, achievements of the project did not last for long because of a lack of Thai stakeholders' commitment and JICA's post-project management. It is concluded that a development agency should consider impacts and sustainability of flood risk management projects more carefully from the stage of planning, and the practical application of the knowledge, and technologies should also be monitored progressively after the completion of the project.

• Earthquakes and Structures
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• v.26 no.6
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• pp.489-499
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• 2024

Infill masonry walls are vulnerable to lateral loads, including seismic, wind, and concentrated push loads. Various strengthening metal fittings have been proposed to improve lateral load resistance, particularly against seismic loads. This study introduces the use of post-compressed wedges as a novel reinforcement method for infill masonry walls to enhance lateral load resistance. The resistance of the infill masonry wall against lateral-concentrated push loads was assessed using an out-of-plane push-over test on specimens sized 2,300×2,410×190 mm³. The presence or absence of wedges and wedge spacing were set as variables. The push-over test results showed that both the unreinforced specimen and the specimen reinforced with 300 mm spaced wedges toppled, while the specimen reinforced with 100 mm spaced wedges remained upright. Peak loads were measured to be 0.74, 29.77, and 5.88 kN for unreinforced specimens and specimens reinforced with 100 mm and 300 mm spaced wedges, respectively. Notably, a tighter reinforcement spacing yielded a similar strength, as expected, which was attributed to the increased friction force between the masonry wall and steel frame. The W-series specimens exhibited a trend comparable to that of the displacement ductility ratio. Overall, the findings validate that post-compressed wedges improve the out-of-plane strength of infill masonry walls.

• Wind and Structures
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• v.26 no.3
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• pp.163-177
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• 2018

Tornadoes are one of the world's deadliest natural phenomena. They are characterized by short life span and danger. It has been observed through post-damage surveys that localities with large numbers of buildings suffer major damage during a tornado attack resulting in huge loss of life and property. Thus,it is important to study interfering buildings exposed to tornado-like vortices. The present study focuses on external and internal pressures developed on building models exposed to translating tornado-like vortices in the presence of an interfering building model. The effects of translating speed and swirl ratio of a tornado-like vortex on external and internal pressures for a principal building in the vicinity of an interfering building are investigated. Results indicate that external and internal pressures are enhanced or reduced depending on the location of the interfering building with respect to the principal building.