• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.372-382
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• 2023

Purpose: Suggests measures to improve the construction company's safety management system according to the enforcement of the Severe Accident Punishment Act. Method: The effectiveness of practice-oriented disaster prevention activities was analyzed through safety and health diagnosis of the level of safety and health management system for the countermeasures against the Severe Accident Punishment Act implemented at the construction site and headquarters. Result: The effect of reducing the accident rate and the advancement of the safety and health management system were analyzed by linking the Severe Accident Punishment Act with the safety and health management system, and a plan to improve the safety and health management system was presented through the analysis of the comprehensive results of safety activities before and after the implementation of the Severe Accident Punishment Act. Conclusion: The effect of practical performance measurement was manifested through the improvement of business owners' awareness, the expansion of investment for disaster prevention, and the quantification of disaster prevention activities according to the enforcement of the Severe Accident Punishment Act.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.477-485
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• 2020

Finite element (FE) model based structural damage detection (SDD) methods play vital roles in effectively locating and quantifying structural damages. Among these methods, structural model updating should be conducted before SDD to obtain benchmark models of real structures. However, the characteristics of updating parameters are not reasonably considered in existing studies. Inspired by the l_∞ norm regularization, a novel anti-sparse representation method is proposed for structural model updating in this study. Based on sensitivity analysis, both frequencies and mode shapes are used to define an objective function at first. Then, by adding l_∞ norm penalty, an optimization problem is established for structural model updating. As a result, the optimization problem can be solved by the fast iterative shrinkage thresholding algorithm (FISTA). Moreover, comparative studies with classical regularization strategy, i.e. the l₂ norm regularization method, are conducted as well. To intuitively illustrate the effectiveness of the proposed method, a 2-DOF spring-mass model is taken as an example in numerical simulations. The updating results show that the proposed method has a good robustness to measurement noises. Finally, to further verify the applicability of the proposed method, a six-storey aluminum alloy frame is designed and fabricated in laboratory. The added mass on each storey is taken as updating parameter. The updating results provide a good agreement with the true values, which indicates that the proposed method can effectively update the model parameters with a high accuracy.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.415-424
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• 2020

Recently, many structural damage detection (SDD) methods have been proposed to monitor the safety of structures. As an important modal parameter, mode shape has been widely used in SDD, and the difference of vectors was adopted based on sensitivity analysis and mode shapes in the existing studies. However, amplitudes of mode shapes in different measured points are relative values. Therefore, the difference of mode shapes will be influenced by their amplitudes, and the SDD results may be inaccurate. Focus on this deficiency, a multi-strategy SDD method is proposed based on the included angle of vectors and sparse regularization in this study. Firstly, inspired by modal assurance criterion (MAC), a relationship between mode shapes and changes in damage coefficients is established based on the included angle of vectors. Then, frequencies are introduced for multi-strategy SDD by a weighted coefficient. Meanwhile, sparse regularization is applied to improve the ill-posedness of the SDD problem. As a result, a novel convex optimization problem is proposed for effective SDD. To evaluate the effectiveness of the proposed method, numerical simulations in a planar truss and experimental studies in a six-story aluminum alloy frame in laboratory are conducted. The identified results indicate that the proposed method can effectively reduce the influence of noises, and it has good ability in locating structural damages and quantifying damage degrees.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.188-188
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• 2016

The Mekong which is one of the world's most significant rivers plays an extremely important role to South East Asia. Lying across six riparian countries including China, Myanmar, Thailand, Laos, Cambodia and Vietnam and being a greatly biological and ecological diversity of fishes, the river supports a huge population who living along Mekong Basin River. Therefore, much attention has been focused on the giant Mekong Basin River, particularly, the soil erosion and sedimentation problems which rise critical impacts on irrigation, agriculture, navigation, fisheries and aquatic ecosystem. In fact, there have been many methods to calculate these problems; however, in the case of Mekong, the available data have significant limitations because of large area (about 795 00 km2) and a failure by management agencies to analyze and publish of developing countries in Mekong Basin River. As a result, the Universal Soil Loss Equation (USLE) model in a GIS (Geographic Information System) framework was applied in this study. The USLE factors contain the rainfall erosivity, soil erodibility, slope length, steepness, crop management and conservation practices which are represented by raster layers in GIS environment. In the final step, these factors were multiplied together to estimate the soil erosion rate in the study area by using spatial analyst tool in the ArcGIS 10.2 software. The spatial distribution of soil loss result will be used to support river basin management to find the subtainable management practices by showing the position and amount of soil erosion and sediment load in the dangerous areas during the selected 56- year period from 1952 to 2007.

• Journal of the Korean GEO-environmental Society
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• v.20 no.3
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• pp.5-14
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• 2019

This study attempted to study the soil erosion dynamic in the Bagmati Basin of Nepal. In this study, an inclusive methodology that combines Revised Universal Soil Loss Equation (RUSLE) and GIS techniques was adopted to determine the distribution of soil loss in the study basin. As well, this study attempts to study the intensity of soil erosion in the seven different land use patterns in the Bagmati Basin. Soil loss is an associated phenomenon of hydrologic cycle and this dynamic phenomenon possesses threats to sustainability of basin hydrology, agriculture system, hydraulic structures in operation and overall ecosystem in a long run. Soil conservation works, and various planning and design of watersheds works demands quantification of soil loss. The results of the study in Bagmati Basin shows the total annual soil loss in the basin is 22.93 million tons with an average rate of 75.83T/ha/yr. The computed soil loss risk was divided into five classes from tolerable to severe and the spatial pattern was mapped for easy interpretation. Also, evaluation of soil loss in different land use categories shows barren area has highest rate of soil loss followed by agriculture area. This is a preliminary work and provides erosion risk scenario in the basin. The study can be further used for strategic planning of land use and hydrologic conservation works in a basin.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.35-45
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• 2015

Total industrial accident rate in Korea is facing a record 0.7% for 10 years since 2000. After entering the continuous versus 0.6% (0.69%) in 2010. In 2011, the decrease was reduced to 0.65%. Conversely In contrast to foreign workers' share has increased dramatically over 10 years since 2000 to 2010 are expected to be difficult in the accident rate of 0.5% for the entry. Despite the ongoing disaster reduction efforts to reduce disaster (share) of foreign workers has been increasing rapidly Survey, Whilst the provision of disaster prevention system status and problem analysis and identify measures that can be established through such disaster reduction measures are urgently needed.

• Journal of the Society of Disaster Information
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• v.6 no.1
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• pp.62-76
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• 2010

Constructions of skyscrapers have been planned and are being performed in Korea, but the research on disaster preparedness and response is mainly focused on construction safety, fire prevention and response, and legal enforcement. So research on physical and psychological effect on human residents, methodology of increased survival rate and decreased disability rate is insufficient. Authors intended to identify the characteristics of skyscraper on human health and safety in disaster, to examine the basic influence of skyscraper on physical and psychological health and the way to decrease the negative effect on human survival.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.241-242
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• 2016

Recently, the interests in safety and prevention from disaster are increasing. In particular, lifeline networks such as water line and sewerage, electricity, gas, and road would be damaged from a disaster. If the lifeline networks do not work in normal, national public service will not properly function. Researches in social network analysis have been conducted for analyzing the interdependency between individuals since 1970s. These network analysis are utilized to investigate a spread of information and disease. However, it is hard to discover the analyzed cases including characteristics of nodes of networks in the area of transportation and disaster. Therefore, this study conducts network analysis of flooded road with flooding scenarios, investigates safe evacuation routes in flooded road network, and suggests efficient approaches for preventing damages from a flooding.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.157-158
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• 2023

본 연구는 건설기계에 의한 협착 및 충돌재해의 예방을 위해 사용하고 있는 스마트 안전관리 시스템 중 건설기계 근접 방지시스템의 재해예방 효과를 분석하여 그 안전성을 실증하고자 하였다. 건설기계 중 재해다발 및 위험성이 높은 굴삭기를 대상으로 스마트 안전관리 시스템의 유무에 따라 근로자(1,000명 기준)의 행동 변화를 라이다 센스 장비를 활용하여 분석하였다. 근로자-건설기계와 최단 이격거리, 위험구역 내 근로자의 체류시간, 위험구역 주변 근로자의 이동 경로 및 체류시간에 따른 근로자의 분포도 등 근로자의 행동 패턴을 분석한 결과스마트 안전관리 시스템을 설치한 건설기계가 미설치한 건설기계보다 근로자와의 이격거리 확보와 위험구역내 체류시간을 단축한 결과를 도출하였다. 이는 스마트 안전관리 시스템이 건설기계와 관련한 협착 및 충돌 등에 의한 재해로부터 근로자의 안전성을 확보한 결과라 분석되었다.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.118-129
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• 2013

Due to the recent surge in natural disasters, with rising social concerns, investment on research & development (R&D) project in natural disaster mitigation area is continuously increasing. However, current R&D performance management system of natural disaster mitigation area does not properly reflect characteristics and social ripple effects of R&D projects. It is indicated that mainly due to the current performance index consists of easy-quantification factors and the performance evaluation system adopts simple aggregation method. Therefore, the purpose of this study is to develop new performance evaluation system considering characteristics and social ripple effects of natural disaster mitigation R&D projects. To this ends, this study derived 3-dimensional performance measurement index through literature review and natural disaster mitigation R&D projects analysis. Finally, based on the derived performance measurement index, this study suggested new and effective performance evaluation system for natural disaster mitigation R&D projects.