본 연구에서는 옹벽 구조물의 내진성능 평가를 위해 2차원 유한요소 해석을 수행하였다. 2차원 유한요소 모델은 실제로 시공된 옹벽 구조를 기반으로 2차원 평면변형 요소로 모델링되었으며, 지반은 각각 유한요소와 무한요소로 모델링 하였다. 지진하중은 총 38개의 인공 지진을 생성하여 사용하였고, 생성된 인공 지진파를 11개의 PGA로 나누어 총 418회의 시간이력해석을 수행하였다. 수치해석 결과를 바탕으로 옹벽 구조물의 지진에 대한 취약도를 분석하였다. 취약도 분석 결과 콘크리트 및 철근의 취약도 곡선이 낮은 PGA 수준에서 급격히 변하는 것을 관찰할 수 있었다. 유한요소 해석 결과를 바탕으로 실제 현장의 옹벽 구조에서 상대적으로 낮은 수준의 지진파가 발생하더라도 높은 파괴확률로 인해 지진에 상대적으로 취약함을 확인하였다.

The TRM method applied in this study is a method aiming at long span and low girder hight of the temporary bridge. When the preload is introduced to the girder member and the preload is removed after by welding the stiffener, a prestress is introduced through the stiffener to increase the load capacity of the member. Therefore, in this study, the structural performance improvement through the application of the TRM method was verified experimentally by the bending tests of the specimens with and without the TRM method.

감자에 바이러스를 매개하는 진딧물은 여름기주와 겨울기주 사이를 이동하는 기주전환을 한다. 해발 600~800m에 위치한 고랭지에서 바이러스 매개 진딧물의 월동 여부는 씨감자 재배 측면에서 매우 중요한 정보가 된다.여름기주(감자, 배추 등)에서 겨울기주(주로 장미과 수목류)로 이동하여 월동하는 진딧물 종류를 알아보기 위하여1~3월에 걸쳐 강원 고랭지(평창군, 횡성군) 감자밭 주변의 수목류 55종의 가지를 채취하여 실험실에서 수피와눈 주변에 월동중인 진딧물 알을 조사하였다. 그 결과 벚나무, 사과나무, 복숭아나무, 아로니아 등 11종의 수목류에서진딧물 월동알을 확인하였다. 진딧물은 BLASTN으로 종동정하였는데, 복숭아혹진딧물(Myzus persicae), 홉사마귀진딧물(Phorodon humuli), 붉은테두리진딧물(Rhopalosiphum rufiabdominalis), 자작나무진딧물(Euceraphis betulae) 등 9종을 확인하였다. 최근 강원 고랭지의 겨울철 기온상승으로 매개진딧물의 발생량이 증가하는 만큼 앞으로 지역별진딧물 확산 예측과 바이러스 매개율 변화에 대한 연구를 진행할 예정이다.

Experimental evaluation of torsional behavior, which is possible behavior of seismic beams of RC structures, was carried out. Concrete strength and stirrup spacing were set as experimental variables to investigate the torsional strength of RC beams. Based on the experimental results, the torsional strength of RC beams was compared and analyzed. From the experimental results, the concrete strength was caused a difference of about 30% in the torsional strength of the maximum torque of the RC beam specimen, and the stirrup spacing was found to be about 2.8 times and 5 times that of the peak torque. Therefore, this study will be an important study to understand the effect of both concrete strength and stirrup spacing for the torsional strength or torsional behavior of RC beams.

In recent years, the number of earthquakes has increased worldwide. There has been an extreme increase on the Korea Peninsula, which is considered a safety zone for earthquakes. In particular, in the event of earthquakes, most structures on the Korea Peninsula are severely damaged, because most are not designed to withstand them. Damage to and destruction of civil structures, such as bridges, nuclear facilities, and dams, is worse than that of other structures. It is necessary to evaluate and predict the extent of damage by earthquake magnitude, as the magnitude of earthquakes is increasing as well as the frequency. A major feature of the occurrence of earthquakes is uncertainty. For this reason, it is necessary to adopt a stochastic approach, and studies using this approach are increasing. However, although there have been several studies on bridges and nuclear facilities, there have been few studies on probabilistic seismic risk evaluation for multi-functional weirs. Thus, this study presents 3D multi-functional weirs and performs a time history analysis by using LS-DYNA, a general structure analysis program. Probabilistic seismic fragility assessment is conducted by Monte Carlo simulation.

Torsional constants of both rectangular cross section and circular cross section are induced by exact solution, and was easy to calculate since of simple shape. However, it is very difficult to calculate the torsional constant of both an arbitrary cross-section and a composite cross-section. In this study, a finite element formulation was proposed as a method to calculate the torsional constant of both an arbitrary cross-section and a composite cross-section. From the numerical study, numerical results was compared with exact solution.

In this study, finite element analysis of korean precast concrete panels was performed and 3D infinite element modeling was used. Infinite elements can be formulated in time domain and nonlinear behavior analysis is possible. Based on the numerical results, the performance of the packing layer of korean precast concrete panels was examined.

Numerical behavior of FRP(Fiber Reinforced Polymer) panel in steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.

Two steel-frame joint specimens with welding joint parts were constructed and evaluated. Two types of displacement load, monotonic and cyclic, were used to evaluate the steel-frame joint specimens. According to the experimental results, the maximum moment of the cyclic test results was 80% smaller than that of the monotonic test results. Local buckling was observed in the compression area of the H-beam flange. A finite element analysis model based on the experimental results was proposed to analyze the steel-frame joint specimens. The numerical results predicted the experimental behavior of the steel-frame joint specimens well. Therefore, it is possible to use the proposed finite element analysis model to evaluate middle- and low-rise steel-frame buildings constructed in South Korea.

The number of earthquakes is increased recently. A electrical equipment is very important in all electric system because it can make a serious problems in such as nuclear power plants like a black out. So, seismic safety design of electrical equipment is necessary to keep to use the convenience of electronics. In this study, threshold values of electronic equipment was founded out from the numerical results by using seismic load.

A behavior of FRP(Fiber Reinforced Polymer) panel in a steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.

The UV/chlorine process is a UV-based advanced oxidation process for removing various organic pollutants in water. The process is becoming increasingly popular because of its effectiveness in practice. It is important to the safe and efficient operation of a UV/chlorine process that the optimal operating conditions for both target removal objective and saving energy are determined. Treatment efficiency of target compounds in UV/chlorine process was mainly affected by pH and scavenging factor. In this study, kinetic based mathematical model considering water characteristics and electrical energy dose calculations model was developed to predict of treatment efficiency and optimal operating conditions. The model equation was validated for the UV/chlorine process at the laboratory scale and in pilot tests at water treatment plants.

Abstract: In this study, finite element analysis modeling is proposed to evaluate middle- and low-rise steel-frame buildings constructed in South Korea. Two steel-frame joint specimens with welding joint parts were constructed and evaluated. Two types of displacement load, monotonic and cyclic, were used to evaluate the steel-frame joint specimens. According to the experimental results, the maximum moment of the cyclic test results was 80% smaller than that of the monotonic test results. Local buckling was observed in the compression area of the H-beam flange. A finite element analysis model based on the experimental results was proposed to analyze the steel-frame joint specimens. The numerical results predicted the experimental behavior of the steel-frame joint specimens well. Therefore, it is possible to use the proposed finite element analysis model to evaluate middle- and low-rise steel-frame buildings constructed in South Korea.

해발 600~1,000 m에 위치한 고랭지에서 주로 재배하는 여름배추는 매년 다양한 병해충의 발생으로 안정적 생산에 어려움을 겪는 실정이다. 최근 기후변화에 따라 벼룩잎벌레, 무테두리진딧물, 배추좀나방 등의 발생이 증가하고 있는 추세지만 대부분 고랭지권이 상류수계에 위치한 특성 때문에 농자재 저투입 농법에 대한 요구가 높다. 현재 친환경농업에서 해충 유인용으로 많이 사용하고 있는 점착판(sticky card, 350×250 ㎜) 트랩을 색깔과 모양을 달리하여 고랭지배추 해충 방제용에 적용하였다. 점착판(노랑, 파랑, 노랑+파랑+노랑, 파랑+노랑+파랑, 노랑+파랑, 파랑+노랑) 트랩 6종을 배추밭 3곳에 설치하고 1주일 간격으로 해충과 천적의 유인 밀도를 조사하였다. 그 결과 무테두리진딧물은 노랑+파랑, 노랑+파알+노랑 트랩에, 벼룩잎벌레는 노란색이 하위에 배치된 트랩에서 유인력이 높았다. 배추좀나방은 생육 초기에 노랑+파랑+노랑 트랩에서 유효하였다. 진딧물의 천적인 등에류는 초기에 발생한 진딧물을 억제하는 효과를 보였으나 파란색의 점착트랩에 많이 유인되는 것으로 나타났다.