In this study, a PTZ(Pan-Tilt-Zoom) system was applied as the methods for measuring the deformation angle of a steel pipe elbow. An image of the steel pipe elbow was enhanced using an image filter processing algorithm. To measure the deformation angle, the Hough transform was applied to the enhanced image to facilitate line recognition. In this study, the limit state of the elbow was defined as rupture or leakage. To verify the validity of measuring the deformation angle of a steel pipe elbow by using a PTZ system, an in-plane cyclic loading test was conducted so that deformation angles that are too large to measure using a conventional sensor could be measured effectively.

최근 해상교통량이 증가하고 선박교통 관제구역이 확대됨에 따라 관제사의 업무 부하가 증가하고 있으며, 이로 인해 교통량이 급증하는 경우 관제사가 위험을 인지하지 못하는 상황도 발생하게 된다. 이러한 배경에서 본 논문에서는 관제 업무의 지원을 위해 이상 거동 선박을 자동으로 식별하는 방법을 제안한다. 본 방법은 누적된 AIS 데이터를 이용하여 관제구역 내의 통항 패턴을 학습하고, 학습된 모델과 의 비교를 통해 이상치를 계산하여 이상 거동 선박을 식별한다. 특히, 선박의 거동 상태에 대한 분류 정보가 없더라도 비지도 학습법을 기반으로 항적 데이터를 자동으로 분류하여 통항 패턴을 학습할 수 있으며, 항적의 군집화와 분류 과정을 통해 이상 거동 선박을 실시간으로 식별 할 수 있는 특징을 가진다. 또한, 본 논문에서는 선박운항 시뮬레이터 및 실제 AIS 항적 데이터를 이용한 식별 실험을 수행하였으며, 이를 통해 선박교통관제 시스템에의 활용 가능성을 고찰하였다.

Cement-milk filled in prebored space has high possibility to leak into surrounding soil when ‘prebored and precast piles’ are constructed according the soil and ground water conditions. The effects of this phenomenon on the lateral resistance are analyzed through the static lateral resistance tests. The 15 mock-up piles are installed to the ground and cement-milk is filled up to the 100% , 75%, and 50% of total lengths of piles from the bottom.

Recently, concrete-steel hybrid girder is being developed to improve economic efficiency and durability. To evaluate flexural behavior of the proposed girders, 17.0m full-scale joint was fabricated and tested under vertical loading. The study was examined vertical displacement; the strain of the reinforcement; and the crack patterns in the concrete. The proposed girders was analyzed to be safe in all members.

Blast-resistant doors are installed to protect human life, precious equipments and materials in the plant and other similar industrial facilities, national important SOC, evacuation facilities and military shelter. In this study structural behavior according to the boundary condition is analyzed. For the simulation the FE program LS-DYNA is used. Anaylsis results will be used to design blast-resistant door in detail.

The objective of this study is to identify reasonable repair and reinforcement methods by performing an analysis and analysis and measurement of corrosion that occurred at the bridge support due to leakage from the expansion joint device.

In this study, a PTZ(Pan-Tilt-Zoom) system was developed to analyze the behavior characteristics of pipe fittings and joints using the image processing techniques. In the developed PTZ system, two cameras and lenses were installed in a pan-tilt drive to measure the strain and deformation angle of the piping components using one system. In-plane cyclic loading test was conducted to verify the validity of the method to measure the strain and deformation angle using the developed PTZ system.

Load test is performed to obtain the data to evaluate load carrying capacity and check static & dynamic characteristics of a structure by estimating the real behavior of bridge due to loading the load. The subject facility in this paper is a bridge located on the spiilway of dam and traffic is relatively less than most brige. Considering the age and operation rules of a dam, however, load test and structure programming analysis were performed to check current conditions for structure under in-depth inspection and the results of that analysis are shown.

기존 거더 형식의 교량이나 슬래브 교량에서는 신축이음장치, 받침, 역T형 교대 및 별도의 접속슬래브 구조를 이루는 시스템으로 이루어져 있다. 이러한 시스템은 신축이음부의 빈번한 파손으로 인한 비용증가, 모멘트 재분배가 낮은 구조로 인한 내구성 감소 등의 문제가 있다. 상기의 문제를 개선하기 위해 일체식 및 반일체식 복합 교량을 제안하고 구조해석을 통해 안전성을 검토하였다. 검토결과 단면강성은 작 지만 접속슬래브와 본체 구조가 연속 강결된 다연속‧ 프레임 구조계 형성과 상부구조의 경간과 단면강성의 균형으로 인하여 모멘트재분배와 힘전달이 확실하게 이루어져 기존교량에 비해 구조안전성 높은 구조임을 확인하였다.

본 연구에서는 다공성 매질의 공극율과 투수능 그리고 유체의 동점성 계수와 같은 물리적 특성에 따른 유체흐름의 비선형 거동에 대한 수치적 분 석을 수행하였다. 적용된 수치모형은 ANSYS CFX 3차원 유동해석 모형이며, 모형의 검증은 기존의 물리적 실험 결과 및 수치모의 결과의 적용을 통해 수행되었으며, 적용된 압력경사와 유속과의 관계 그리고 마찰계수와 레이놀즈 수와의 관계에 대해 비교적 잘 일치하였다. 다공성 매질의 공극 율과 투수능 그리고 유체의 동점성 계수의 값을 변화시키면서 모의한 결과 유체의 동점성 계수가 다공성 매질의 유체흐름의 비선형 거동에 가장 큰 영향을 미치는 것으로 나타났다.

The purpose of measuring a dam operated after design & construction is to properly operate reservoir and maintain dam structural safety by comparing the really measured data for the behavior of dam with the data for design & construction, the past mesured data and analyzing them. In this paper, the really measured data is analized for a dam facilitiy located near a seismic epicenter of earthquake that occurred on 12th, Nov. 2016 in Gyeong-ju and the results of safety inspection for a dam is shown by comparing the behavior of dam before and after occuring earthquake

In the sliding slab track of railway bridge, a lateral support block is used to control the lateral displacement. Therefore, it is important to analyze the behavior of dowel rebar and the lateral support block of the sliding slab track. In this study, high strength concrete and steel rebar was selected to analyze the behavior of dowel rebar and shear behavior of high strength dowel rebar and the lateral support block were compared to the equations developed by Soroushian et al. (1986) and CEB-FIP (2010).

The failure of piping in nuclear power plants and various plant facilities is mainly caused by vibration due to fluid pressure, dead load, temperature expansion and earthquake load in the pipe. Repeated stresses due to vibration cause local fatigue failure on pipe joints where stress is concentrated, which is a factor that hinders the safety of the structure. Therefore, the vibration problem is solved by installing devices to solve the vibration problem in the pipe where vibration frequently occurs. In this study, we developed a damper that damps the dynamic load generated by piping using the friction pendulum principle, and analyzed the behavior curve of the MER-Spring specimen to be used.

Studies on the lattice girder of the cross sectional form and construction works through laboratory experiments have been performed. The numerical analysis for structural behavior such as deflection and stresses on the lattice girder, however, are insufficient. In this study the stiffness of a lattice girder was examined by using MIDAS.

In this study, experiment using H-beam specimens was carried out and finite element analysis was conducted using the same method as the test. As a result, although experimental strength value was approximately 10% higher than analytical value, load-strain relationships from the experiment and analysis were relatively similar to each other.

For areas with the diverse contamination sources, the change of 4-nitrophenol contamination and impact of potential contamination sources have been evaluated using monitoring data and a numerical model (HydroGeoSphere). The model considered several parameters including land cover, precipitation, and flow rate. And, the model has been performed to investigate the effect of decay rate of 4-nitrophenol. The results of the simulations showed that the influence on 4-nitrophenol in downstream was mainly greater than that in upstream, and the tributaries did not significantly affect the mainstream because of their low flow rates. In addition, the effect of contamination sources was simulated for each section, then the measured data were higher than the corresponding simulated data in most sections of the Geumho river. In particular, the impact of the potential contamination sources in the upstream area was much higher than that in the other area, thus more monitoring data for the upstream area is required.

The purpose of measuring a dam operated after design & construction is to properly operate reservoir and maintain dam structural safety by comparing the really measured data for the behavior of dam with the data for design & construction, the past mesured data and analyzing them. In this paper, the really measured data is analized for a dam facilitiy located near a seismic epicenter of earthquake that occurred on 12th, Nov. 2016 in Gyeong-ju and the results of safety inspection for a dam is shown by comparing the behavior of dam before and after occuring earthquake.

In the sliding slab track of railway bridge, a lateral support block is used to control the lateral displacement. Therefore, it is important to analyze the behavior of dowel rebar and the lateral support block of the sliding slab track. In this study, high strength concrete and steel rebar was selected to analyze the behavior of dowel rebar and shear behavior of high strength dowel rebar and the lateral support block were compared to the equations developed by Soroushian et al. (1986) and CEB-FIP (2010).

이 논문에서는 원자력발전소나 각종 플랜트 시설물에서 배관을 보호하기 위하여 마찰방식을 이용한 댐퍼를 개발하여 성능을 분석 하는 연구를 수행하였다. 마찰방식댐퍼는 MER-Spring에 압축력을 가하여 베어링과 샤프트에 마찰력을 발생시켜 진동을 감쇠시키는 장치이 다. 댐퍼의 성능을 분석하기 위하여 MER-Spring과 마찰재의 재료특성을 분석하고, 마찰의 영향에 대한 연구를 수행하였으며, 이에 대한 거동 방정식을 수립하였다. 또한 재료의 변형 여부를 판단 및 수립된 거동방정식의 신뢰성 검토를 위하여 시작품을 제작하였고 시편으로 제작된 댐 퍼의 성능 시험과 유한요소 해석을 통하여 이를 분석하였다. 그 결과, 재료의 신뢰성이 확인되었고 마찰계수는 속도에 따른 보정이 필요하며, 반복재하 실험 및 유한요소해석 결과 우수한 결과를 나타냄을 확인하였다. 또한, 추후에 동적하중에 대한 검토가 수행되어 이 연구의 성과가 더 넓은 범위에 적용되었으면 한다.

This paper introduces unfamiliarity index (UFI) that calculated from the FFT results of the short term timeline acceleration responses. If this algorithm, which can detect an abnormal behavior from the maximum constant signal, is used to the terminal sensors of an structure, more accurate safety control criteria will be prepared efficiently.