• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.241-242
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• 2021

In this study, we develop the damage depth diagnostic technology of fire damage concrete and propose an method of impaired depth due to fire by drying impaired concrete after immersing. Test results indicated that when assesing impared depth due to fire with the dry method after water immersing, impaired depth was clearly found and furthermore, compared with that by Phenolphthalein method 10 mm of damage depth was additionally identified, which is imposible to asses when Phenolphthalein is applied.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.245-246
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• 2021

In this study, we develop the damage depth diagnostic technology of fire damage concrete and propose an method of impaired depth due to fire by drying impaired concrete after immersing. Test results indicated that when assesing impared depth due to fire with the dry method after water immersing, impaired depth was clearly found and furthermore, compared with that by Phenolphthalein method 15 mm of damage depth was additionally identified, which is imposible to asses when Phenolphthalein is applied.

• 항공우주시스템공학회지
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• 제4권1호
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• pp.23-26
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• 2010

In this study, it was performed damage assesment of small scale composite aircraft developing. This aircraft adopted the sandwich structure to skin of wing. This study aims to investigate the residual strength of sandwich composites with Nomex honeycomb core and carbon fiber face sheets after the open hole damage by the experimental investigation. The 4-point bending tests were used to find the bending strength, and the open hole was applied to introduce the simulated damage on the specimen. The bending strength test results after open hole was compared with the results of no damaged specimen test. The FEM analysis is assessed via an experimental 4-point bending test.

• 대한환경공학회지
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• 제31권3호
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• pp.223-231
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• 2009

환경친화적인 도로노선대 선정을 위하여 공간분석기능을 활용한 GIS 기반 환경성평가 기법을 개발하고 실제 사례노선을 통하여 검증해 보고자 하였다. 도로건설 사업으로 인해 환경훼손을 가져오는 요인에 관한 분석을 바탕으로 영향범주를 구체화 시킨 후, 이에 관한 다양한 등급화 사례 및 법적 규제에 관한 문헌조사를 수행하였다. 공간 분석을 위한 정량화 모델로는 AHP를 선택하였다. 환경성 평가항목으로는 지형지질, 동식물, 토양생태, 수질, 대기질, 소음진동, 토지이용, 위락경관의 8개 항목을 선정하고 그에 따른 세부지표를 구성하여 이를 3등급 체계로 구분하였다. 가중치 산정을 위해 쌍대비교에 의한 설문수행 결과 동식물 1등급의 가중치가 0.191로 가장 높게 산출되었다. 위 방법을 사례지역에 대하여 검증한 결과 가장 환경친화적인 도로노선대를 생성할 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.161-162
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• 2010

본 연구에서는 콘크리트 구조물인 교량의 교각과 같은 압축부재의 충격하중을 정량적인 손상지수로 평가하기 위해서 동적유한요소해석 프로그램인 LS-DYNA를 이용하여 차량의 충격각도에 따른 충격도, 세장비 등을 변화시켜 case별 해석을 수행하였다. 본 연구결과를 통해 콘크리트 구조물의 거동해석 및 설계기법을 Bayesian 통계방법을 이용하여 충격하중을 받을 시의 성능기반형 설계기법을 산정하였으며, 이는 실제 충격하중에 의한 구조물의 방호성능 및 설계 시에 적절하게 적용할 수 있을 것으로 판단된다.

• 한국농공학회논문집
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• 제59권3호
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• pp.21-28
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• 2017

The main goal of this paper is to assess application of UAV (Unmanned Aerial Vehicle) remote sensing and GIS based images in detection and measuring of rice field drought area in South Korea. Drought is recurring feature of the climatic events, which often hit South Korea, bringing significant water shortages, local economic losses and adverse social consequences. This paper describes the assesment of the near-realtime drought damage monitoring and reporting system for the agricultural drought region. The system is being developed using drought-related vegetation characteristics, which are derived from UAV remote sensing data. The study area is $3.07km^2$ of Wonbuk-myeon, Taean-gun, Chungnam in South Korea. UAV images were acquired three times from July 4 to October 29, 2015. Three images of the same test site have been analysed by object-based image classification technique. Drought damaged paddy rices reached $754,362m^2$, which is 47.1 %. The NongHyeop Agricultural Damage Insurance accepted agricultural land of 4.6 % ($34,932m^2$). For paddy rices by UAV investigation, the drought monitoring and crop productivity was effective in improving drought assessment method.

• 한국터널지하공간학회 논문집
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• 제4권1호
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• pp.3-12
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• 2002

본 연구는 우면산터널 시공에 따른 예술의 전당내의 오페라극장 구조물에 대한 영향을 검토하고 필요시에는 적절한 대책을 조기에 강구하기 위하여 3차원 유한요소해석을 실시하였다. 쌍굴터널 굴진시 지반거동의 영향범위내에 있는 오페라극장은 문화재급의 건축물로써 그 기초형식 또한 다양하다. 그러므로, 건물구조의 3차원적인 특성과 기초형태의 변화를 이상적으로 모델링하고, 3차원해석 결과에 따른 시공전 예측과 시공중 안정성확인을 평가할 수 있도록 검토하였다. 문제발생시 신속한 대처를 할 수 있고, 터널굴진시 정보화 시공이 적용될 수 있도록 관리기준치를 단계적으로 변화 설정하였다.

• 대한조선학회논문집
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• 제56권2호
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• pp.161-167
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• 2019

In general, fatigue analysis is performed by using deterministic model to estimate the optimal parameters. However, the deterministic model is difficult to clearly describe the physical phenomena of fatigue failure that contains many uncertainty factors. With regard to this, efforts have been made in this research to compare with the deterministic model and the stochastic models. Firstly, One deterministic S-N curve was derived from ordinary least squares technique and two P-S-N curves were estimated through Bayesian-linear regression model and Markov-Chain Monte Carlo simulation. Secondly, the distribution of Long-term fatigue damage and fatigue life were predicted by using the parameters obtained from the three methodologies and the long-term stress distribution.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2101-2108
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• 2008

Most of train fires which occur in usual cases do not grow up significantly on a large scale enough to bring about casualties and harmful damages. However, the consequence of some train fire accidents can be devastating disaster so that it would be even recorded in history in unusual cases. Accordingly, such a probability of fire disaster cannot be ignored in aspect of the railway safety assesment. A scale of injury and damage is very difficult to predict and analyze. Because it is depend on various factors, i.e. fire load, burning period, facilities, environment condition, and so on. Thus, a prediction of fire load could be understood as a one methodology to estimate railway safety assesment. The summation method which is one of them is used to evaluate the overall fire load by assuming that sum of heat release rate per unit area or mass of each composite material equals the total. However, since the train fire is classified into a compartment fire in under-ventilation condition. The summation method do not estimate a fire load completely. In this journal, Various methods to predict fire load are introduced and evaluated. Especially the fire simulation tool FDS(Fire Dynamics Simulator)which is based on the CFD(Computational Fluid Dynamics) is introduced, too. Through the FDS simulation, numerical analyses for the fire load and flame spread are performed. Then, these results of the simulation are validated through the comparison study with the experimental data. Then, limitations and approximations including in simulation process are discussed. The future direction of research is proposed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.453-456
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• 2003

This research is to evaluate the seismic performance of reinforced concrete bridge piers with lap-spliced longitudinal reinforcement steels in the plastic hinge region, and to develop the enhancement scheme of their seismic capacity. Six circular columns of 0.6m diameter and 1.5m height were made with two confinement steel ratios. They were damaged under series of artificial earthquakes that could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading simultaneously under an axial load, P=$0.1f_{ck}A_{g}$, and residual seismic performance of damaged columns was evaluated. Test results show that RC bridge piers with lap-spliced longitudinal steels behaved with minor damage even under artificial earthquakes with 0.22g PGA, but failed at low ductility subjected to the subsequent quasi-static load test. This failure was due to the debonding of the lap splice. The specimens externally wrapped with composite FRP straps in the potential plastic hinge region showed significant improvement both in flexural strength and displacement ductility.