• 한국방재학회 논문집
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• 제9권1호
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• pp.151-158
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• 2009

많은 사람들이 집중강우와 태풍으로 임한 침수로 고통 받고 있다. 비록 하천의 제방을 강화시키고 사람들의 생명과 재산을 보호하기 위하여 펌프장을 건설함에도 불구하고, 침수피해는 제어되지 않고 오히려 증가하고 있다. 미국에서는 재해를 사전에 예방하기 위해 강우자료 해석, 홍수위 계산, 홍수피해 규모를 통합시스템에서 수행 할 수 있는 CWMS 프로그램을 연구하고 있다. 그러나 이러한 프로그램을 바로 국내에 이용하기에는 하천수위, 홍수재해모의 등과 같은 데이터 구축 에 부족함이 많기 때문에 우리의 침수피해를 평가하기에는 많은 어려움이 있다. 그러므로 우리의 상황에 맞는 침수피해평가를 위한 체계적인 데이터 수집과 분석시스템이 필요한 실정이다. 이번 연구의 주된 목적은 침수재해로 부터 생명과 재산을 보호하기 위해 유용하게 사용할 수 있도록 체계적인 데이터 수집과 평가방법을 제안하는 것으로 강우로부터 홍수 피해를 평가할 수 있도록 기존 모형과 많은 인자가 고려된 침수피해 평가시스템(Flood Damage Evaluation Model; K-FDEM)을 제안하였다.

• 융합보안논문지
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• 제21권1호
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• pp.115-120
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• 2021

최근 온라인을 중심으로 광고를 수행하고 오프라인에서 실제로 물건을 매매하는 O2O 기반의 부동산중개 웹 사이트 혹은 앱이 폭발적으로 증가하고 있는 추세이다. 이로 인해서 기존의 오프라인 기반의 부동산중개 환경에서 온라인 기반으로 환경이 변화됨으로써 소비자들이 시간, 비용, 편리성 측면에서 매우 높은 호감을 얻고 있다. 하지만, 온라인 기반의 부동산중개 서비스들의 편리함 이면에 잘못된 정보 또는 악의적인 허위정보로 인해서 사용자들이 시간, 금전적으로 피해를 보게 되는 경우도 자주 발생하고 있다. 그러므로 본 연구에서 O2O 기반의 부동산중개 서비스에서 발생 가능한 소비자의 피해를 줄이고자 인공지능 기술을 활용해 등록된 매물정보에 대한 진위 여부를 판별할 수 있는 허위 매물정보 필터링 시스템을 설계하였다. 제안한 연구방법을 통해서 온라인 부동산 서비스에 등록되는 매물정보에 대한 진위 여부를 판별할 수 있을 뿐만 아니라, 소비자의 시간적, 금전적 피해를 줄일 수 있음을 보였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.252-253
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• 2017

The appearance & spread of new kind of virus might cause national economic shrinkage and reduction of foreign tourist. Finally, severe damage of national economy happens. This research wants that after property analysis for generally applied building interior materials, specifically eco-environmental materials including functional materials are reviewed, classified and their special properties in building were investigated.

• 한국해양공학회지
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• 제18권2호
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• pp.25-32
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• 2004

We surveyed the coastal structure damage created by typhoon ‘Maemi’, which heavily struck the Korean peninsula on September 12, 2003. The survey revealed that high tides and strong winds induced by the typhoon were the main causes of the coastal damage, especially in the Busan areas. Though some experimental real-time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete system should be implemented to save human lives and property from huge typhoon disasters.

• Smart Structures and Systems
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• 제2권2호
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• pp.127-140
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• 2006

In this study, a wavelet-based covariance-driven system identification technique is proposed for damage assessment of structures under ambient excitation. Assuming the ambient excitation to be a white-noise process, the covariance computation is shown to be able to separate the effect of random excitation from the response measurement. Wavelet transform (WT) is then used to convert the covariance response in the time domain to the WT magnitude plot in the time-scale plane. The wavelet coefficients along the curves where energy concentrated are extracted and used to estimate the modal properties of the structure. These modal property estimations lead to the calculation of the stiffness matrix when either the spectral density of the random loading or the mass matrix is given. The predicted stiffness matrix hence provides a direct assessment on the possible location and severity of damage which results in stiffness alteration. To demonstrate the proposed wavelet-based damage assessment technique, a numerical example on a 3 degree-of-freedom (DOF) system and an experimental study on a three-story building model, which are all under a broad-band excitation, are presented. Both numerical and experimental results illustrate that the proposed technique can provide an accurate assessment on the damage location. It is however noted that the assessment of damage severity is not as accurate, which might be due to the errors associated with the mode shape estimations as well as the assumption of proportional damping adopted in the formulation.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.227-230
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• 2009

In order to predict failure behavior of advanced high-strength steel sheets (AHSS) in hole expansion tests, damage model was developed considering surface condition sensitivity (with specimens prepared by milling and punching: 340R, TRIP590, TWIP940). To account for the micro-damage initiation and evolution as well as macro-crack formation, the stress triaxiality dependent fracture criterion and rate-dependent hardening and ultimate softening behavior were characterized by performing numerical simulations and experiments for the simple tension and V-notch tests. The developed damage model and the characterized mechanical property were incorporated into the FE program ABAQUS/Explicit to perform hole expansion simulations, which showed good agreement with experiments.

• 소성∙가공
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• 제3권1호
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• pp.120-132
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• 1994

Strip drawing of strain-hardening, viscoplastic materials with damage is analyzed by a rigid plastic finite element method. A process model is formulated using two state variables, one for strain hardening from slip dominated plastic distortion and the other for damage from growth of microvoids. Application of the model to aluminum strip drawing is given via implementation in a consistent penalty finite element formulation. The predicted density changes as a result of void growth are compared to those from experiments reported in the literature. The effects of drawing conditions such as drawing speed and die angle on the mechanical property chages are studied.

• 대한기계학회논문집
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• 제19권4호
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• pp.1033-1040
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• 1995

To simulate strength reliability and durability of ceramic parts under gas turbine application environments, particle impact damage behaviors in silicon carbide oxidized at 1673 K and 1523 K for 200 hours in atmosphere were investigated. The long-term oxidation produced a slight increase in the static fracture strength. Particle impact caused a spalling of oxide layer. The patterns of spalling and damage induced were dependent upon the property and impact velocity of the particle. Especially, the difference in spalling behaviors induced could be explained by introducing the formation mechanism of lateral crack and elastic-plastic deformation behavior at impact sit. At the low impact velocity regions, the oxidized SiC showed a little increase in the residual strength due to the cushion effect of oxide layer, as compared with the as-received SiC without oxide layer.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.164-165
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• 2014

In the case of U.S, various damage prediction models of buildings from natural disasters have been used widely in many organizations such as insurance companies and governments. In South Korea, although studies regarding damage prediction model of hurricane have been conducted, the scope has been only limited to consider the property of hurricane. However, it is necessary to consider various factors such as socio-economic, physical, geographical, and built environmental factors to predict the damages. Therefore, as a basic study on a damage prediction model development of buildings, this study is to analyze the correlation between various factors related to hurricane. The findings of study can be utilized to develop for predicting the damage of hurricane on buildings.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.171-174
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• 2004

In order to improve the damage tolerance of the conventional laminated composites, three­dimensional fiber structures incorporated with stitching yams have been utilized in this study. From the newly developed process termed as TAPIS(TApe Placement Incorporated with Stitching), carbon/epoxy composites have been fabricated. Two-dimensional composites with the same stacking sequence as 3D counterparts have also been fabricated for the property comparison. To examine the damage resistance performance the low speed drop weight impact test has been adopted. For the assessment of damage after the impact loading, specimens were subjected to C-scan nondestructive inspection compression after impact(CAI) were also conducted to evaluate residual compressive strength. Although the damage area of 3D composites was greatly reduced$(30-40\%)$ compared with that of 2D composites, the CAI strength did not show drastic improvement.