• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1003-1008
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• 2001

It is recently reported that bond failure can be initiated in the region where maximum bending moment and shear force is acted by accompanying shear deformation after flexural crack in full-scale RC beams strengthened by CFRP. Such a shear deformation effect causing bond failure is relatively little in the case of small-scale specimens. So, additional reinforcing details to the critical beam section where maximum moment and shear were acted is required to prevent the bond failure caused by the shear deformations. The U-type wrapping methods by CFRP to the critical beam section is proposed and tested in this paper. Also, the applicability of design bond strength derived from the tests of small-scale beam was investigated by the full-scale RC beam strengthened by CFRP.

• 한국농촌건축학회논문집
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• 제7권1호
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• pp.121-128
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• 2005

This experimental study was conducted to investigate beam strengthening of RC buildings with expended steel plate(ESP) in rural area. Nine test specimens were manufactured, whose variables were tensile steel ratio and the amount and the shape of expanded steel plate. The test results indicated that strengthened beams with ESP showed the improvement of flexural strength of 50%~90%, and the beam strengthening of U type was excellent for shear reinforcement as well as flexural reinforcement, more over, the honeycomb shape of ESP and anchor bolts for development of ESP were very effective.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2574-2580
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• 2002

In this paper, an experimental verification has been conducted for the frequency response function (FRF)-based structural damage identification method (SDIM) proposed for beam structures. The FRF-based SDIM requires the natural frequencies and mode shapes measured in the intact state and the FRF-data measured in the damaged state. Experiments are conducted for the cantilevered beam specimens with one slot and with three slots. It is shown that the proposed FRF-based SDIM provides damage identification results that agree quite well with true damage state.

• 한국구조물진단유지관리공학회 논문집
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• 제3권4호
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• pp.145-153
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• 1999

The major objective of this study is to investigate experimentally the shear strengthening effect of carbon fiber sheets upon reinforced concrete deep beam and shear failure behavior variation of reinforced concrete deep beam strengthened by carbon fiber sheets. Tests are carried out with 6 specimens were shear failure at first loading tests, and with parameters including the types of shear strengthening of carbon fiber sheets (I type, S type, U type), and plies of sheets (2 ply and 1 ply). From the results of test, analyzed load-deflection of midspan, strain variation of main bars and transverse reinforcement, maximum load capacity of strengthened specimens, and compared with the previous test results.

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 하계학술발표회 논문집
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• pp.187-189
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• 2008

The spatial coherence function of multy-mode beam was measured by using a Sagnac interferometer and self referencing technique. For leaner polarization laser beam passing through a multy-mode fiber, its change value of spatial mode and polarization from stress of faber and input coupling angle. And each spatial mode have each polarizations, when we simulation Wigner distribution function and Spatial Correlation function of spatial multi-mode beam by using Hermit Gaussian modes leaner sum. We measured spatial coherence function of using by multy-mode fiber. One can use this measurement method to study and characterize the property of multy-mode light field coming out of GRIN multy-mode fiber.

• 항공우주산업기술동향
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• 제7권2호
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• pp.33-39
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• 2009

1968년 미국의 피터 글레이저 박사가 정지궤도에 위성을 띄워 태양 에너지를 직접 받아 전기로 변환하여 지구로 송전하는 거대한 태양광위성의 개념을 소개한 바 있다. 이에 대해 미국, 일본, 유럽 등에서는 우주태양광 발전을 미래의 새 에너지원으로 주목하여 활발한 기초 연구와 개념 설계 그리고 최근에는 본 사업의 실현을 위한 구체적인 방안까지 발표하고 있는 실정이다. 현재 우주태양광발전 기술은 계속 개발 중으로 미국과 일본에 서는 2030 년경에 실용화할 계획으로 있다. 본 논문에서는 그린에너지와 새 에너지원으로 주목받고 있는 우주 태양광발전에 대한 선진국의 기술 동향 및 국내의 추진 전략에 대하여 기술하였다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.94-96
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• 2002

In order to achieve the radiotherapy more precisely using highly energetic heavy charged particles, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. We can directly obtain the 2-D distribution of the electron density in a sample from a heavy ion CT image. For this purpose, we have developed a heavy ion CT system using a broad beam. The performance, especially the position resolution, of this system is estimated in this work. All experiments were carried out using the heavy ion beam from the HIMAC. We have obtained the projection data of polyethylene samples with various sizes using He 150 MeV/u, C 290 MeV/u and Ne 400 MeV/u beams. The used targets are the cylinders of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. The dependence of the spatial resolution on the target size and the kinds of beams will be discussed.

• 터널과지하공간
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• 제28권1호
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• pp.25-37
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• 2018

미고결 암석에 대한 Creep 특성을 분석하고자 Burger 모델을 이용하였다. Burger 모델은 자료쌍 D(u,t)으로부터 4개의 역학적 매개변수를 결정 하여야 한다. 본 연구에서는 수학적 개념 해를 적용하여 매개변수를 결정 하였다. 미고결 암석에 대한 Burger 모델의 결정된 매개변수를 이용하여 Creep을 3년간 가속시켰다. 그 결과 Creep 거동은 수렴이 되지 않고 지속적인 변형거동을 보였다. 따라서 본 광산에서는 Roofbolt 보다 U-Beam 적용이 안정성 측면에서 더 적합 할 것으로 분석 되었다.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2006년도 제5회 추계학술대회 및 정기총회
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• pp.182-186
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• 2006

• 한국광학회:학술대회논문집
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• 한국광학회 2005년도 제16회 정기총회 및 동계학술발표회
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• pp.214-215
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• 2005