• Tribology and Lubricants
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• 제25권3호
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• pp.163-170
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• 2009

We developed a compact micro indentation testing device (designated SNUT) which is capable to measure Young's modulus of a sample using depth and applied load data during indentation. Performance of this device was evaluated using pure Ti, pure Ni, and die steel (SKD11). As a result of analysing the indentation test data, the frame compliance $C_f$ was found to influence mainly the modulus by 80% among several factors affecting accuracy of Young's modulus. Project area, which was determined by indirect indentation method, was modified using direct SEM observation. Finally, Young's modulus error was reduced to 5% after taking into consideration the frame compliance and modified projected area from 80% error without any these two correction factors. The performance of SNUT and MTS instruments was compared using same specimen (pure Ti).

• 한국농공학회지
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• 제45권4호
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• pp.98-106
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• 2003

In order to set up structural improvement strategy against meteorological disasters of the shading structures in ginseng fields, structural safety analyses as well as some case studies of structural damage patterns were carried out. According to the results of structural safety analysis, allowable safe snow depth for type B(wood frame with single span) was 25.9 cm, and those for type A(wood frame with multi span) and type C and D (steel frame with multi span) were 17.6 cm, 25.8 cm, and 20.0 cm respectively. So types of shading structures should be selected according to the regional design snow depth. An experiential example study on meteorological disasters indicated that a strong wind damage was experienced once every 20 years, and a heavy snow damage once every 9.5 years. The most serious disasters were caused by heavy snow and it was found that a half break and complete collapse of structures were experienced by about 70% of snow damage. In addition to maintenance, repair and reinforcement, it is also recommended that improved model of shading structures for ginseng cultivation should be developed as a long term countermeasures against meteorological disasters.

• 한국차세대컴퓨팅학회논문지
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• 제14권6호
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• pp.87-97
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• 2018

강우량은 매우 중요한 기상 정보이다. 일반적으로, 도로 수준과 같은 높은 공간 해상도의 강우량이 더 높은 가치를 가진다. 하지만, 도로 수준의 강우량을 측정하기 위해 충분한 수의 기상 관측 장비를 설치하는 것은 비용 관점에서 비효율적이다. 본 논문에서는 도로의 감시 카메라 영상으로부터 강우량을 인식하기 위해 심층 신경망을 활용하는 방법에 대해 제시한다. 해당 목표를 달성하기 위해, 본 논문에서는 교내 두 지역의 감시 카메라 영상과 강우량 데이터를 수집했으며, 새로운 심층 신경망 구조인 Temporal and Spatial Segment Networks(TSSN)를 제안한다. 본 논문에서 제시한 심층 신경망으로 강우량 인식을 수행한 결과, 프레임 RGB와 두 연속 프레임 RGB 차이를 입력으로 사용했을 때, 높은 성능으로 강우량 인식을 수행할 수 있었다. 또한, 기존의 심층 신경망 모델과 비교했을 때, 본 논문에서 제안하는 TSSN이 가장 높은 성능을 기록함을 확인할 수 있었다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2016년도 하계학술대회
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• pp.228-230
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• 2016

본 논문은 깊이 영상 기반의 렌더링 방식을 이용하는 다시점 영상 시스템에서 새로운 프레임율 변환(Frame Rate Up-Conversion, FRUC) 방식을 소개한다. 제안된 방식은 깊이 영상을 이용해 각각의 블록을 세부 영역으로 나누고, 주변 시점의 영상을 이용해 각각 세부 영역의 폐쇄 영역의 정보를 복원한다. 복원된 폐쇄 영역의 정보와 기존의 세부 영역의 정보를 이용해 움직임 예측 및 보상을 수행한다. 제안하는 방법은 폐쇄 영역이 발생하는 영역에서 기존의 방법보다 정확한 움직임 예측을 수행한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.223-228
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• 1999

The state of the current design practice in designing the so-called hybrid structures with the upper shear-wall and lower frame systems are reviewed through the investigation of the 43 design examples. In particular, the trend in the design of the transfer system between upper wall and lower frame systems are analyzed with respect to the depth, the length and the number of spans of transfer deep girders and the number of upper stories. Finally the most critical portions in this conventional transfer system, which should be studied in depth in the future, are pointed out to improve the current design and analysis practice.

• Design & Manufacturing
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• 제12권3호
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• pp.31-35
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• 2018

In this paper, the method of improving the flatness and perpendicularity for a corner fixing bracket of the large display frame is studied through experiments. Three specimens were tested, one specimen not subjected to bending line before bending, and two specimens with a straight groove with 0.2 mm and 0.5 mm depth. Experimental results show that the flatness of bracket becomes worse with deeper depth. When there is no straight groove, the perpendicularity becomes worse. For the flatness correction, a restriking process was added. The twist of bracket was corrected by performing the restriking with a curvature larger than the twist amount in the direction opposite to the deformed direction. We also found that the perpendicularity is maintained regardless of the amount of curvature with the restriking process.

• Earthquakes and Structures
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• 제20권1호
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• pp.29-38
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• 2021

According to ACI 224.3R-95 (ACI, 2013), construction joints (cold joint) in the column are to be provided at the top of floor slab for column continuing to the next floor and underside of floor slab and beam. A recent study reveals that providing cold joint of the mentioned location significantly reduced the seismic performance of the frame structures. Since, the construction joints in multi-story frame structures normally provided at the top of the floor slabs and at soffit of the beam in the column. This study investigated the effect of construction joint at various location in the column of beam-column joint such as at the top of floor slab, soffit level of the beam, half the depth of beam below the soffit of the beam and at a full depth of the beam below the soffit of the beam. The study revealed that there is an improvement in seismic capacity of the specimens as the location of cold joint is placed away from the soffit of the beam for lower story column.

• Structural Engineering and Mechanics
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• 제58권1호
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• pp.103-119
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• 2016

Multi-storey frame structures are frequently exposed to static and dynamic forces. Therefore analyses of static (buckling) and dynamic stability come into prominence for these structures. In this study, the effects of number of storey, static and dynamic load parameters, crack depth and crack location on the in-plane static and dynamic stability of cracked multi-storey frame structures subjected to periodic loading have been investigated numerically by using the Finite Element Method. A crack element based on the Euler beam theory is developed by using the principles of fracture mechanics. The equation of motion for the cracked multi-storey frame subjected to periodic loading is achieved by Lagrange's equation. The results obtained from the stability analysis are presented in three dimensional graphs and tables.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2011년도 추계학술대회
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• pp.288-291
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• 2011

Video stabilization is an important image enhancement widely used in surveillance system in order to improve recognition performance. Most previous methods calculate inter-frame homography to estimate global motion. These methods are relatively slow and suffer from significant depth variations or multiple moving object. In this paper, we propose a fast and practical approach for video stabilization that selects the most reliable key frame as a reference frame to a current frame. We use optical flow to estimate global motion within an adaptively selected region of interest in static camera environment. Optimal global motion is found by probabilistic voting in the space of optical flow. Experiments show that our method can perform real-time video stabilization validated by stabilized images and remarkable reduction of mean color difference between stabilized frames.

• 전기전자학회논문지
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• 제16권4호
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• pp.369-374
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• 2012

본 논문에서는 손동작을 영상 입력 정보로 하여 기기의 기능을 제어하는 UX를 구현하였다 이를 위하여 Microsoft 사의 Kinect 센서를 이용하여 초당 30 프레임의 사용자의 3차원 depth map을 얻고 여기서 skeleton 이미지를 추출하여 손목 등의 관절의 위치에 대한 좌표 값을 얻는다. 전 후 프레임의 손의 위치가 변화하는 방향과 병화량으로부터 손 동작의 의미를 추출하고 다양한 손동작을 이용하여 스마트TV 등의 원격의 영상을 제어하는 명령어 입력으로 사용하는 UX를 제시하고 실험을 통하여 구현하였다.