• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.153-156
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• 2008

Comparative analysis of forest fire danger rating on the forest characteristics of thinning area and non-thinning area on forest fire burnt area was studied in this work. To investigate the effect of thinning slash in forest fire, Gangneung-si Wangsan-myeon, Ulgin-gun Wonnam-Myeon, Samchok-si Gagok-Myeon, in which forest fire broke out, were selected. As a result that investigated forest fire danger ratio between thinning slash and non-thinning slash, leeward scorching ratio(36%), crown damage ratio(29%), mortality of branch at the former are higher than those at the latter, leeward scorching ratio of tree, where thinning slash is around, is 10%-20% higher than that of independent tree. So I estimate that thinning slash has a some effect on the intensity of forest fire. And the result to investigate damage of forest fire according to tree species shows that leeward scorching ratio of conifer is 5% higher than that of non-conifer, and mortality of branch of the former is 19% higher than that of the latter. It is considered that forest fire may affect directly to a tree trunk if it diffuse to piled thinning tree because there was no space between thinning trees and trees. Furthermore, it was found that re-ignition had a chance to occur due to lots of piled thinning trees.

• 한국산림과학회지
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• 제108권4호
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• pp.618-627
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• 2019

최근 멧돼지와 같은 야생동물에 의한 작물 및 시설물 피해가 매우 심각한 사회적 문제로 대두되고 있다. 이 연구는 산악형 국립공원 인근 산촌주민들의 야생동물로 인한 농작물 및 임산물 피해액을 추정하는 것을 목적으로 한다. 이를 위해 2016년 4월과 6월에 지리산 국립공원과 인접한 구례군 토지면에 위치하는 6개 산촌마을을 조사하였고, 84가구로부터 얻은 자료를 토대로 분석하였다. 2015년 기준, 84가구의 야생동물에 의한 농작물 및 임산물 피해 추정액은 총 1억 3,863만원이었고, 가구당 연평균 165만원의 피해를 입었다. 이 중 야생동물에 의한 피해액이 가장 큰 것은 밤, 고사리, 돌배, 복숭아, 감자 등의 순이었으나, 단위면적당 피해액이 가장 큰 것은 고구마, 복숭아, 옥수수, 감자 등의 농작물이었다. 구례군 전체 농작물 및 임산물 생산지의 잠재적인 야생동물 피해액은 연간 약 40억 원으로 추정되었고, 구례군의 야생동물 피해 보상을 위한 연평균 예산액은 피해액의 0.9%에 불과한 것으로 나타났다. 따라서 잠재적인 야생동물 피해에 대비하여 피해보상제도의 실효성을 높이기 위해서는 지자체의 재정자립도와 야생동물 피해의 책임을 고려하여 국가가 재정을 지원해야 함을 시사한다. 또한 산촌의 지속가능성을 위한 안정적인 작물 생산을 위해서는 형평성을 고려한 보상정책을 개발하고, 야생동물 피해예방시설의 효과성과 예방 지원 정책을 개선해야 한다.

• 한국토양비료학회지
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• 제50권1호
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• pp.1-11
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• 2017

In order to assess risk of high temperature damages about corn during reproduction stages in the future, we carried out analysis of climate change scenarios RCP (Representative Concentration Pathway) 4.5 and RCP8.5 distributed by KMA (Korea Meteorological Administration) in 2012. We established two indexes such as average of annual risk days of high temperature damage which express frequency and strengthen index of high temperature damage. As results of producing maps for 157 cities and counties about average of annual risk days of high temperature damage during total periods of scenarios, the risk of high temperature in RCP8.5 was evaluated to increase at all over nation except inland area of Gangwon province, while RCP4.5 showed similar to present, or little higher. The maps of annual risk days of high temperature damage with 10 years interval in RCP8.5 prospected that the risk for damaging corn growth would increase rapidly from 2030's. The largest risk of high temperature damage in the future of RCP8.5 was analyzed at Changnyeong county located east-south inland area in Kyeongnam province, while the smallest of risk counties were Pyeongchang, Taebaek, Inje, and Jeongseon. The prospect at 12 counties which is large to produce corn at present and contains large plains have been showed that there will be only a little increase of risk of high temperature at Goesan, Yangpyeong, Hongcheon, Seosan, and Mooju until 2060's. But considering strengthen index of high temperature damage, most regions analyzed would be prospected to increase rapidly after 2030's. To cope with high temperature damage of corn in the future, we should develop various practical technologies including breeding adapted varieties and controlling cultivation periods.

• 한국산업융합학회 논문집
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• 제23권6_2호
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• pp.1043-1050
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• 2020

In this study, a study was presented on the monitoring technique of landslide area using UAV. In the case of disaster investigation using drone mapping, it can be used at various disaster sites. The mission can be carried out at various disaster sites, including surveys of damage to mountainous areas caused by landslides, building collapses surveys of flood damage, typhoons, earthquakes. The damage investigation plan using drone mapping is expected to be highly utilized at disaster sites where investigators cannot access it like in mountainous areas and where it is difficult to conduct direct damage investigations at the site. Drone mapping technology has many advantages in terms of disaster follow-up, such as recovery. Compared to the existing survey system, which was mainly carried out manually, the investigation time can be drastically reduced, and it can also respond to disaster sites that are difficult to carry out or are difficult to access directly. In addition, it is possible to establish and guide spatial data at the disaster site based on accurate mapping data from the time of the disaster, which has considerable strength in managing the situation of the disaster site, selecting priority areas for recovery, and establishing recovery plans. As such, drone mapping is a technology that can be used in a wide range of sites along with natural disasters and social disasters. If a damage investigation system is established through this, it is believed that it will contribute significantly to the rapid establishment of recovery plans along with the investigation of disaster response time and extent of damage recovery.

• Earthquakes and Structures
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• 제4권3호
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• pp.299-324
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• 2013

The current research focuses on the seismic vulnerability assessment of typical Southern Europe buildings, based on processing of a large set of observational damage data. The presented study constitutes a sequel of a previous research. The damage statistics have been enriched and a wider damage database (178578 buildings) is created compared to the one of the first presented paper (73468 buildings) with Damage Probability Matrices (DPMs) after the elaboration of the results from post-earthquake surveys carried out in the area struck by the 7-9-1999 near field Athens earthquake. The dataset comprises buildings which developed damage in several degree, type and extent. Two different parameters are estimated for the description of the seismic demand. After the classification of damaged buildings into structural types they are further categorized according to the level of damage and macroseismic intensity. The relative and the cumulative frequencies of the different damage states, for each structural type and each intensity level, are computed and presented, in terms of damage ratio. Damage Probability Matrices (DPMs) are obtained for typical structural types and they are compared to existing matrices derived from regions with similar building stock and soil conditions. A procedure is presented for the classification of those buildings which initially could not be discriminated into structural types due to restricted information and hence they had been disregarded. New proportional DPMs are developed and a correlation analysis is fulfilled with the existing vulnerability relations.

• 대한건축학회논문집:구조계
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• 제35권3호
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• pp.3-10
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• 2019

On November 15, 2017, an earthquake($M_L5.4$) occurred in Pohang. Pohang earthquake was the second largest earthquake since earthquake was observed in Korea, but structural damage caused by earthquake was biggest. Structural damage caused by Pohang earthquake was mainly caused by schools and pilotis, above all damage to pilotis was outstanding. This is because area where pilotis structures are concentrated is located near epicenter, and seismic performance of pilotis structures is not excellent compared with general structures. In this study, described results of damage investigation and analysis of damage causes through analysis of pilotis Structures on 131 buildings that were investigated immediately after Pohang earthquake. In addition, cause of damage was analyzed through analysis of seismic wave. Investigation site was selected to Jangseong-dong, where damage occurred in large numbers. Damage level was classified into A, B, and C level by measuring residual crack width and story drift of structural members.

• Structural Engineering and Mechanics
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• 제16권5호
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• pp.581-595
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• 2003

Since the conventional direct approaches are hard to be applied for damage diagnosis of complex large-scale structures, a two-step approach for diagnosing the joint damage of framed structures is presented in this paper by using artificial neural networks. The first step is to judge the damaged areas of a structure, which is divided into several sub-areas, using probabilistic neural networks with natural Frequencies Shift Ratio inputs. The next step is to diagnose the exact damage locations and extents by using the Radial Basis Function (RBF) neural network with the second Element End Strain Mode of the damaged sub-area input. The results of numerical simulation show that the proposed approach could diagnose the joint damage of framed structures induced by earthquake action effectively and has reliable anti-jamming abilities.

• 대한기계학회논문집
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• 제19권9호
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• pp.2105-2113
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• 1995

The compressive tests under impact conditions were performed to establish a design guide for impact damage tolerance. The composition of layup was selected for the real cases of composite aircraft structure. The energy level of visible of visible damage threshold was determined as 7 Joules. It was found that the normalized bending stiffnesses in the direction of closely fixed boundary affected the area of damage. Graphite/epoxy used in the tests exhibited 60% reduction in compression strength at the energy level of visible damage threshold. Wet-conditioned specimens represented 9% reduction in residual compressive strength in comparison with room temperature ambient specimens. In this study, a design factor of 2.1 was proposed for the low velocity impact damage.

• 한국자원식물학회지
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• 제35권2호
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• pp.169-182
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• 2022

본 연구는 산불피해가 발생한 접경지역 산림 내 희귀특산식물(개느삼) 분포를 예측하고 피해를 정량화하고자 수행되었다. 이를 위해 산불피해강도에 따른 산림면적 피해(NBR), 임상도를 통한 수종별 피해(Vegetation map), MaxEnt 모델 분석을 수행, 보다 정밀한 결과를 도출하고자 하였다. 우선, 산불피해강도 분석은 위성영상(Landsat-8)을 활용하여, 산불피해강도(ΔNBR_2016-2015)를 분석하고 피해범위를 도출하였다. 임상도 작성은 환경부의 토지피복도, 산림청의 임상도, 자체적으로 식생조사를 진행하여, 산불 전·후의 임상도를 작성하고, 수종 피해 및 변화를 확인하였다. 마지막으로 MaxEnt 모델 분석은 관련문헌과 자체조사 자료를 기준으로 작성된 개느삼 실제서식지 좌표를 활용하여, AUC(Area Under Curve) 값을 도출하였다. 분석된 결과의 정밀도를 높이고자, 임상도와 결합하여, 개느삼이 주로 분포하는 소나무 군락 및 소나무-참나무림 군락을 대상으로 재분석한 결과, 대상지 내 개느삼 실제출현 좌표 325개소 중 299개 지점에서 개느삼 출현가능성이 92.0%로 예측되어 유의미한 결과를 얻을 수 있었다. 해당 자료를 산불피해강도(ΔNBR_2016-2015) 자료와 중첩한 결과, 산불피해지 내 개느삼 서식가능지(예측) 면적 44,760 m²의 45.9%인 20,552 m²가 훼손된 것을 확인할 수 있었다. 따라서 본 연구는 산불로 인해 훼손된 희귀식물 서식지 면적을 정량화하고 희귀식물 보전·관리를 위한 사례가 될 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제17권5호
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• pp.655-670
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• 2004

This paper aims to evaluate the effect of typhoons on fatigue damage accumulation in steel decks of long-span suspension bridges. The strain-time histories at critical locations of deck sections of long-span bridges during different typhoons passing the bridge area are investigated by using on-line strain data acquired from the structural health monitoring system installed on the bridge. The fatigue damage models based on Miner's Law and Continuum Damage Mechanics (CDM) are applied to calculate the increment of fatigue damage due to the action of a typhoon. Accumulated fatigue damage during the typhoon is also calculated and compared between Miner's Law and the CDM method. It is found that for the Tsing Ma Bridge case, the stress spectrum generated by a typhoon is significantly different than that generated by normal traffic and its histogram shapes can be described approximately as a Rayleigh distribution. The influence of typhoon loading on accumulative fatigue damage is more significant than that due to normal traffic loading. The increment of fatigue damage generated by hourly stress spectrum for the maximum typhoon loading may be much greater than those for normal traffic loading. It is, therefore, concluded that it is necessary to evaluate typhoon induced fatigue damage for the purpose of accurately evaluating accumulative fatigue damage for long-span bridges located within typhoon prone regions.