• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.4
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• pp.211-219
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• 2019

In this study, SMG(Smart Material with Grease) was developed, which was improved the precipitation minute particle in grease during long term standstill. Also, small-sized cylinder damper equipped with an electromagnet in a piston was developed for using a performance evaluation of the damper with SMG and the dynamic load test, and damping force using Power model and Bingham model was derived in order to compare to the result of that of the damper. The data obtained from the dynamic load test were analyzed and plotted, and then a dynamic range was calculated to evaluate the usability of the damper with SMG. The performance of the damper with SMG was compared to the damping forse derived from the Power and Bingham model. The result of this evaluation shown that the usability of SMG damper was demonstrated by this test as a semi-active controlling equipment of small-sized damper.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.294-294
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• 2021

강우에 따른 수위예측은 수자원 관리 및 재해 예방에 있어 중요하다. 기존의 수문분석은 해당지역의 지형 데이터, 매개변수 최적화 등 수위예측 분석에 있어 어려움을 동반한다. 최근 AI(Artificial Intelligence) 기술의 발전에 따라, 수자원 분야에 AI 기술을 활용하는 연구가 수행되고 있다. 본 연구에서는 데이터 간의 관계를 포착할 수 있는 AI 기반의 기법을 이용하여 강우에 따른 수위예측을 실시하였다. 연구대상 유역으로는 과거 수문데이터가 풍부한 설마천 유역으로 선정하였다. AI 기법으로는 머신러닝 중 SVM (Support Vector Machine)과 Gradient boosting 기법을 이용하였으며, 딥러닝으로는 시계열 분석에 사용되는 RNN (Recurrent Neural Network) 중 LSTM (Long Short-Term Memory) 네트워크을 이용하여 수위 예측 분석을 수행하였다. 성능지표로는 수문분석에 주로 사용되는 상관계수와 NSE (Nash-Sutcliffe Efficiency)를 이용하였다. 분석결과 세 기법 모두 강우에 따른 수위예측을 우수하게 수행하였다. 이 중, LSTM 네트워크는 과거데이터를 이용한 보정기간이 늘어날수록 더욱 높은 성능을 보여주었다. 우리나라의 집중호우와 같은 긴급 재난이 우려되는 상황 시 수위예측은 빠른 판단을 요구한다. 비교적 간편한 데이터를 이용하여 수위예측이 가능한 AI 기반 기법을 적용할 시 위의 요구사항을 충족할 것이라 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.103-103
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• 2022

최근 우리나라는 기후변화의 영향에 의해 국지적으로 집중호우가 발생하고 있으며, 홍수로 인해지역적으로 사회적, 경제적 피해가 증가하고 있다. 이에 사전에 홍수로 인한 피해에 대비하고자 기상청에서는 호우특보를 발령하고 있으며, 환경부에서는 하천을 중심으로 홍수특보를 발령하고 있다. 그러나 호우특보는 전국을 동일한 판단기준을 활용하고 있으며, 홍수특보는 하천 중심으로 홍수에 대한 위험을 예보를 제공하여 사전에 행정구역에서 홍수에 대비하는 데에는 한계가 있다. 본 연구에서는 사전에 홍수에 대비하기 위한 방법으로 과거 홍수피해 자료를 활용하여 홍수위험을 평가하고, 이를 활용하여 재난인자인 강우량과 홍수량에 대한 판단 기준을 행정구역별로 제시하고자 하였다. 홍수위험 판단 기준을 설정하기 위해서 과거 홍수피해 사상별 강우량, 홍수피해액, 홍수피해 현상 등을 조사하였으며, 홍수피해 현상은 각종 기사 및 뉴스 등을 활용하여 수집하였다. 강우량 기준은 행정구역 내 존재하는 강우관측소 자료를 활용하였으며, 홍수량 기준 적용 지점은 담당 공무원의 의견과 과거 홍수피해 이력이 있는 지역에 대해 설정하였다. 각 홍수위험 판단기준은 위험정도에 따라 4개로 구분하여 제시하였다. 향후 본 연구에서 제시된 홍수위험 판단기준은 사전에 홍수위험을 인지하고 대비하기 위한 대응단계 설정에 활용 가능할 것으로 판단된다.

• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.305-312
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• 2017

In our society, the advanced, advanced, and information industries have continued to grow and now live in the era of the fourth industrial revolution. As the industry develops, the load of the users has also increased so much that it is deepened by the energy shortage phenomenon and the construction of additional energy facilities is required. Therefore, energy plant construction work is being actively carried out in the coastal area. In particular, it is common to build a plant in the ground by filling the coast with soil in other regions, reflecting the fact that Korea is lacking in the country when constructing power plants, gas and petrochemical plants. Current domestic grounding designs are designed or constructed to suit only the use of grounding resistors based on the electrical equipment design technical standards. However, in the case of a plant facility constructed in the untested buried soil, when the lightning current and the abnormal current are inputted, the facility operator or the user due to the elevation of the ground potential is seriously exposed to the risk of electric shock disaster. In this paper, we analyze the ground resistivity of the landfilled soil and use a computer program (CDEGS) based on KS C IEC 61936-1, We analyze the contact voltage and stratification voltage and propose a grounding design optimized for plant installation.

• Journal of Korea Water Resources Association
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• v.55 no.6
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• pp.421-435
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• 2022

As natural disasters have been increasing due to climate change, sustainable solutions are in need to alleviate the degree of drought hazard, assess and project the drought influence based on future climate change scenarios. In assessing drought risk, socio-economic factors of the region must be considered along with meteorological factors. This study categorized drought hazard, exposure, and vulnerability as three major components of drought risk according to the Intergovernmental panel on Climate Change (IPCC) risk assessment framework, and selected indices for each component to quantify the drought risk in South Korea according to the mid-size basins. Combinations of climate scenarios (Representative Concentration Pathway; RCP 2.6 and RCP 8.5) and socio-economic scenarios (Shared Socio-economic Pathways; SSP 1, SSP2 and SSP3) for the near future (2030-2050) ant the far future (2080-2099) were utilized in drought risk analysis, and results were compared with the historical data (1986-2005). In general, the drought risks for all scenarios shows large increases as time proceeds to the far furture. In addition, we analyzed the rank of drought hazard, exposure, vulnerability for drought risk, and each of their contribution. The results showed that the drought hazard is the most contributing component to the increase of drought risk in future and each basin shows varying contributing components. Finally, we suggested countermeasures for each basin according to future climate change scenarios, and thus this study provides made the basis for establishing drought management measures.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.228-240
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• 2022

A comprehensive safety management system will be required in accordance with the implementation of the Major Disaster Punishment Act for close-up safety management of construction sites. Safety management level evaluation management requires a comprehensive relationship between safety management under the Construction Technology Promotion Act and health and health management system under the Industrial Safety and Health Act. Purpose: Safety under the Serious Accidents Punishment Act. The ultimate goal is to study the comprehensive analysis and relationship of health management and to improve the safety evaluation level of health and health management. Methods: The feasibility of the questionnaire was confirmed through the second Delphi analysis of construction site experts and safety managers, and the regression coefficient and path analysis of potential variants in safety management, safety management, health management and safety inspection were confirmed. Result and Conclusion: In the structural model, the regression coefficient (89%) from safety management, health system, and safety management to safety inspection execution and lambda values of appropriate observation variables were confirmed. In the path analysis, the total effect (.809) was confirmed by mediating health hygiene in the relationship between health plan establishment adequacy and post-inspection management, and the path coefficient (.82) of temporary structure safety was confirmed.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.18-30
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• 2023

Purpose: This study is to contribute to the development of monitoring technology through the increase of confidence in construction monitoring by deriving the analysis of construction monitoring cost and improvement measures of railway tunnel construction in Seoul. Method: It presents the status on design and contract of construction monitoring cost, status on application construction monitoring cost and its analysis, analysis on safety management cost and quality management cost, expansion of application of the price calculation standard for monitoring management services to improve this, and monitoring for direct order of ordering organization. Results: If the monitoring management service that was meanwhile ordered as included in the construction work is performed by the directly selected company of ordering organization through the preliminary screening for bidding qualification, then the improvement of monitoring quality and the accurate monitoring data can be secured. Conclusion: For the price calculation standard for monitoring management service, the application of actual cost addition method under the Engineering Promotion Act and the calculation standard of monitoring management cost for standard estimation for ground survey should be extended through the direct order of ordering organization, not the method to be included in the net construction cost where it is performed by a subcontractor via contractor.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.828-838
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• 2022

Purpose: Through the establishment of a computerized system of risk assessment, the purpose is to analyze the case of whether the co-workers who are subject to the risk assessment at the construction site can easily fill it out and expect disaster reduction through efficient risk assessment activities. Method: By providing the risk factors and safety measures for the work by selecting the type of work, the risk estimation and the establishment of countermeasures can be made, and a system has been established to enable practical disaster prevention activities by presenting disaster cases for the work. Result: Through the analysis of the change in the scaled disaster rate for the years following the on-site application after the establishment of the risk assessment computer system of H Construction Company, it was confirmed that the scaled disaster rate of the domestic construction industry increased, while the conversion disaster rate of H Construction Company decreased. Conclusion: Through the computational systemization of risk assessments, workers in the field can easily access the risk assessment, evaluate the risk factors of the process and establish risk prevention measures, and it has been analyzed that there is an impact on the reduction of the disaster rate during the operational analysis period.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.519-531
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• 2023

With the aim of preventing safety accidents at construction sites, the company aims to create safe behaviors intended through variables called smart safety and health activities to help reduce industrial accidents. Purpose: It analyzes how smart safety and health activities affect accidents caused by unsafe behavior and changes in worker behavior, which is the root cause, and verifies the hypothesis that it helps prevent safety accidents and protect workers' lives. Method: Smart safety and health activities were selected as independent variables (X), and intended safety and anxiety, which are workers' behavioral intentions, were set as dependent variables (Y), attitude and subjective norms, and planned behavioral control as parameters (M). Exploratory factor analysis, discriminant validity analysis, and intensive validity analysis of safety and health activities were used to analyze the scale's reliability and validity. To verify the hypothesis of behavior change, the study was verified through Bayesian model analysis and MC simulation's probability density distribution. Result: It was found that workers who experienced smart safety and health activities at construction sites had the highest analysis of reducing unstable behavior and performing intended safety behavior. The research hypothesis that this will affect changes in worker behavior has been proven, the correlation between variables has been verified in the structural equation and path analysis of the research analysis, and it has been confirmed that smart safety and health activities can control and reduce worker instability. Conclusion: Smart safety and health activities are a very important item to prevent accidents and change workers' behavior at construction sites.

• Journal of the Society of Disaster Information
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• v.4 no.1
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• pp.86-100
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• 2008

It is needed to classify the kinds of construction and demolition(c&d) debris to 6 catagories of waste concrete, waste asphalt concrete, waste wood, scraps, combustible waste and incombustible waste in order to properly do a separate discharge and to estimate unit generation rate in construction site. Also, in this case, the unit treating cost for mixed wastes should be applied with the unit treating cost for combustible waste. The construction standard materials estimation data is used for basic data for estimating unit generation rate. The mixed wastes in this data should be classified to waste wood, combustible waste and incombustible waste, and their ratio is obtained by using the unit generation rate of Asia Pacific Environment and Management Institute and Seoul Metropolitan Development Institute. The waste amounts generated from newly-built construction can be obtained from multiplying the loss rate by the amount of materials used from construction standard estimation data. Also, those from dismantling construction can be obtained by subtracting waste amount generated during newly-built construction from total input amount of materials in newly-built construction. Those in two cases can be used in construction site. It can be used for estimating the amount generated and establishing the treating plan in the case of setting up the policy of waste management and doing the environment impact assessment.