• 한국환경복원기술학회지
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• 제23권6호
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• pp.15-28
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• 2020

Urbanization and industrialization have caused increasing damage to national lands, and ecological restoration has proceeded without any specific assessment of this damage. The purpose of this study is to select indices to assess damaged areas through literature review and panel discussions, and to derive the importance of damaged area assessment indices by analyzing them through the Analytic Hierarchy Process (AHP). This study has derived, via literature review, six types of damage and a total of 18 related assessment indices. A total of 51 responses were collected from surveys and given to experts, and an AHP analysis conducted. As a result of the analysis, "Landform change (0.268)" was of the highest importance, with associated damage types as follows: "Soil contamination (0.193)", "Vegetation damaged (0.149)", "Surface soil loss (0.143)", "Change in soil physiochemical property (0.125)", and "Vegetation decline (0.122)". The analysis determined that the item of the highest importance in the overall assessment of damage was "Slope occurred area (0.100)", and that "Conductivity (0.022)" was of the lowest importance. This study can be presented as a criterion in determining the type and degree of damage in setting priorities for future ecological restoration projects.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.647-650
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• 2004

This paper deals with the damage assessment of the concrete beam using Damage-area concept and the modulus of elasticity reduction of the beam was evaluated. Simply supported concrete beams were loaded at the mid-span. When the displacements from the tests were increased more than $10\%$ of the initial values, flexural cracks occured. Judging from the observed cracks, damaged area of the beams were assumed and the modulus of elasticity reduction using the smeared-cracking concept was estimated to minimize the error between the test results and analytical results. Main parameters for the assessment were height of the crack area, length of the crack area, position of the crack area and the modulus of elastic reduction ratio. In each stage, damaged elements and their stiffness reduction were estimated to minimized the error.

• 한국측량학회지
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• 제37권5호
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• pp.351-357
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• 2019

UAV (Unmanned Aerial Vehicle) images can be exploited for rapid forest fire damage assessment by virtue of UAV systems' advantages. In 2019, catastrophic forest fire occurred in Goseong and Sokcho, Korea and burned 1,757 hectares of forests. We visited the town in Goseong where suffered the most severe damage and conducted UAV flights for forest fire damage assessment. In this study, economic and rapid damage assessment method for forest fire has been proposed using UAV systems equipped with only a RGB sensor. First, forest masking was performed using automatic elevation thresholding to extract forest area. Then ExG (Excess Green) vegetation index which can be calculated without near-infrared band was adopted to extract damaged forests. In addition, entropy filtering was applied to ExG for better differentiation between damaged and non-damaged forest. We could confirm that the proposed forest masking can screen out non-forest land covers such as bare soil, agriculture lands, and artificial objects. In addition, entropy filtering enhanced the ExG homogeneity difference between damaged and non-damaged forests. The automatically detected damaged forests of the proposed method showed high accuracy of 87%.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.60-63
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• 2004

The paper deals with the damage assessment of the concrete beam using static displacements and the flexural stiffness reduction of the beam was evaluated. Simply supported concrete beams were loaded at the mid-span, and the applied load level ranged $20\%,\;40\%,\;80\%$ of the flexural strength of the beam. When the displacements from the tests were increased more than $10\%$ of the initial values, flexural cracks occured. Judging from the observed cracks, damaged area of the beams were assumed and the stiffness reduction using the smeared-cracking concept was estimated to minimize the error between the test results and analytical results. Four stages of the behavior of a RC beam, which are uncracked, initial cracking, stabilized cracking and post-yielding, can be considered to assess the damage of RC beams. Main parameters for the assessment were cracking area and the stiffness reduction ratio. In each stage, damaged elements and their stiffness reduction were estimated to minimized the error.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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• pp.202-211
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• 1996

A number of typical type of steel-box pedestrian bridges are constructed in the metropolitan highway or heavy traffic urban area. Although it has the advantage of speedy construction because of its simple structural form and prefabricated erection method, it has been reported that many of these bridges are deteriorated or damaged and thus are in the state such that it would give unsafe and uncomfortable feeling to pedestrians. In the paper, for the realistic assessment of safety and residual earring-capacity of deteriorated and/or damaged steel box pedestrian bridges, an interactive non-linear limit state model are formulated based on the von Mises' combined stress yield criterion. It is demonstrated that the proposal model is effective for the reliability-based safety assessment and residual carrying-capacity evaluation of steel-box pedestrian bridges. In addition, this study suggests an effective and practical field load test method for pedestrian bridges.

• 상하수도학회지
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• 제25권4호
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• pp.535-546
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• 2011

The study area investigated in this research is Hwaseong city, Gyeonggi-Do where small scale development is currently in progress. For the last three years, we carried out the environmental and ecological assessment by using data from The Ministry of Environment and Han River Basin Environmental Office. Most of development works in Hwaseong city, Gyeonggi-Do are small scale developments which are related with factory and distribution complex based on individual laws and regulations. However, environmental and ecological assessment is not being sufficiently reflected beforehand. Especially, because the development takes place mainly in the outskirts of the city, the fine forest is continuously being damaged. We analyzed changes in green zone area caused by the developments. As a result, the percentage of original green zone was decreasing while the percentage of artificial green zone was increasing. We should maintain the percentage of the original green zone in order to conserve natural environment. In the past three years, the damage of the DGN (Degree of Green Naturality) 7 area that has high conservative value was little, but, there was serious damage in the area of DGN 6. In order to conserve natural environment, political and institutional investigation should be seriously carried out for mitigation of environmental and ecological damages.

• 대한조선학회논문집
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• 제48권5호
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• pp.404-413
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• 2011

It is important to assess and improve the warship survivability for the weapon threats which have a critical effect on warship. The survivability of the warship is defined as the capability of a warship to avoid or withstand a man-made hostile environment. The survivability of the warship consists of three categories (Susceptibility, Vulnerability and Recoverability). Firstly, the susceptibility is defined as the inability of a warship to avoid radars, guns, missiles and etc. Secondly, the vulnerability is defined as the inability of a warship to withstand the man-made hostile environment. Finally, the recoverability is defined as the ability of a warship to recover the damaged components and systems. Among them, this paper has described the vulnerability assessment for the hypothetical system which is composed of critical components. Also, the procedure which is suggested to calculate the vulnerable probability of the damaged warship is based on the Vulnerable Area Method.

• 해양환경안전학회지
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• 제25권1호
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• pp.34-44
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• 2019

해양에서의 이용행위가 최근 사회발전에 따라 점차 대형화, 다양화되고 있으며 이에 따라 해양생태계가 가지는 환경용량을 넘어서 해양생태계의 복원력 및 저항성, 항성상 등이 훼손 또는 저하되고 있다. 이로 인해서 생태계가 가지는 본연의 기능을 발휘하지 못하게 되고 이는 생태계의 서비스와 가치 하락으로 이어진다. 이에 따라 훼손된 생태계를 다시 건강한 생태계로 회복하고자 하는 인식이 증가하고 있으며 그 수단으로써 복원이 관심을 받고 있다. 복원사업이 점차 확대되는 시점에서, 복원사업의 해역이용협의 및 영향평가를 시행함에 있어 발생할 수 있는 다양한 문제점과 앞으로 나아가야 할 방향에 대해서 점검할 필요가 있다. 따라서 본 연구에서는 복원과 관련된 용어를 연구논문 및 보고서를 통해서 복원의 개념을 정리하였고 복원사업과 관련된 해역이용협의 검토 상황 및 복원사업의 현황을 살펴보았다. 또한, 복원사업을 성공적으로 이끌어 갈 수 있도록 해역이용협의서 상의 문제점을 사례조사를 통해서 고찰하였다. 이를 토대로 복원사업의 해역이용협의 및 영향평가에 있어 개선방안을 제시하고자 하였다. 이는 향후 정책 및 계획 수립 등에 있어 유용한 정보를 제공할 수 있을 것으로 판단된다.

• 상하수도학회지
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• 제23권5호
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• pp.619-630
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• 2009

The study area investigated in this research is Hwaseong city, Gyeonggi-Do where small scale development is currently in progress. For the last three years, we carried out the environmental and ecological assessment by using data from The Ministry of Environment and Han River Basin Environmental Office. Most of development works in Hwaseong city, Gyeonggi-Do are small scale developments which are related with factory and distribution complex based on individual laws and regulations. However, environmental and ecological assessment is not being sufficiently reflected beforehand. Especially, because the development takes place mainly in the outskirts of the city, the fine forest is continuously being damaged. We analyzed changes in green zone caused by the developments. As a result, the percentage of original green zone was decreasing while the percentage of artificial green zone was increasing. We should maintain the percentage of the original green zone in order to conserve natural environment. In the past three years, the damage of the DGN (Degree of Green Naturality, 7) area that has high conservative value was little, but, there was serious damage in the area of DGN 6. In order to conserve natural environment, political and institutional investigation should be seriously carried out for mitigation of environmental and ecological damages.

• 환경영향평가
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• 제19권6호
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• pp.563-571
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• 2010

In carrying out the prior review on environmental conditions for basic plan of public waters reclamation, the important item is review on conditions of location on prearranged reclaimed land. In this study, environmental assessment which needs careful consideration in the first stage of selecting location is presented by analyzing environmental impact assessment on public waters reclamation projects for about 10 years. The assessment index for alternative comparison is divided into two parts according to importance level. What is most important in alternative comparison is the comparison on direct influence due to reclamation. In other words, it figures out damaged extent of natural shoreline as well as intertidal and infralittoral zones. Comparing influence extent due to reclamation through the 1st comparison on this is regarded as to be important. In case there is no significant difference by alternatives through the 1st assessment, the 2nd assessment should be carried out. In the 2nd assessment indexes are damaged quantity of benthic organism, change in seawater current, erosion, accumulation and exchangeable rate of seawater. The plan for selecting optimal location which minimizes environmental influence in establishing public waters reclamation plan is demonstrated through model cases. For this, 3 districts which have similar environment and scale are selected, and then comparison on location alternative is made through environmental assessment index. In addition, the comparison on 3 arrangement alternatives are conducted, targeting certain areas. It is thought that carrying out comparison review on respective areas in the same cities and counties, not merely comparing arrangement plan by selecting 1 targeting area in advance, is the most appropriate. Besides, selection of arrangement plan considering environment, which minimizes damage of natural shoreline and influence due to change of seawater current is required in alternative comparison on arrangement plan as well. In case of the prior review on environmental conditions though alternative comparison method presented in this study is carried out, it is safely said that the influence on ocean environment due to public waters reclamation can be minimized.