• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.93-96
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• 2000

The theory of non-prismatic folded plate structures was reported by the senior author in 1965 and 1966. Fiber reinforced composite materials are strong in tension. The structural element for such tension force is very thin and weak against bending because of small bending stiffnesses. Naturally, the box type section is considered as the optimum structural configuration because of its high bending stiffnesses. Such structures can be effectively analyzed by the folded plate theory with relative ease. The "hollow" bending member with uniform cross-section can be treated as prismatic folded plates which is a special case of the non-prismatic folded plates. Tn this paper, the result of analysis of a folded plates with one box type uniform cross-section is presented. Each plate is made of composite laminates with fiber orientation of [ABBCAAB]$_r$, with A=-B=$45^{\circ}$, and C=$90^{\circ}$. The influence of the span to depth ratio is also studied. When this ratio is 5, the difference between the results of folded plate theory and beam theory is 1.66%. is 1.66%.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.707-710
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• 2002

A 120kV/70A high voltage switch has been installed at Korea Atomic Energy Research Institute in Taejon to supply power with Korea Superconducting Tokamak Advanced Research (KSTAR) Neutral Beam Injection (NBI) system. NBI system requires fast cutoff of the power supply voltage for protection of the grid when arc detected and fast turn-on the voltage for sustaining the beam current. Therefore the high voltage switch and arc current detection circuit are important part of the NBI power supply and there are much need for high voltage solid state switches in NBI system and a broad area of applications. This switch consisted of 100 series connected MOSFETs and adopted the proposed simple and reliable gate drive circuit without bias supply, Various results taken during the commissioning phase with a 100kW resistive load and NBI source are shown. This paper presents the detailed design of 120kV/70A high voltage MOSFETs switch and simple gate drive circuit. Problems with the high voltage switch and gate driver and solutions are also presented.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.453-454
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• 2009

본 연구에서는 중 고층 철근콘크리트 주상복합형 건축물에서 지진하중과 같은 반복하중이 작용할 때 단차형 내부 보-기둥 접합부의 거동 특성을 파악하기 위하여 단차 유무에 따른 내부 보-기둥 접합부 실험체를 대상으로 실험을 실시하여 다음과 같은 결론을 얻었다. 단차가 있는 내부 보-기둥 접합부 실험체는 단차가 없는 표준실험체(FJ-0D)와 비교하여 단차 수준(1.0D, 2.0D)이 증가함에 따라 수평내력과 에너지소산능력이 증가하였고 내부 보-기둥 접합부 영역을 중심으로 균열진전 상황이 상이하였다. 또한 에너지소산능력은 내부 보-기둥 접합부 단차가 높을수록 1.1${\sim}$1.35배 증가하였다.

• Journal of Radiation Protection and Research
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• 제47권1호
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• pp.50-57
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• 2022

Background: There are several proton therapy facilities in operation or planned in Taiwan, and these facilities are anticipated to not only treat cancer but also provide beam services to the industry or academia. The simplified approach based on the Monte Carlo-based data sets (source terms and attenuation lengths) with the point-source line-of-sight approximation is friendly in the design stage of the proton therapy facilities because it is intuitive and easy to use. The purpose of this study is to expand the Monte Carlo-based data sets to allow the simplified approach to cover the application of proton beams more widely. Materials and Methods: In this work, the MCNP6 Monte Carlo code was used in three simulations to achieve the purpose, including the neutron yield calculation, Monte Carlo-based data sets generation, and dose assessment in simple cases to demonstrate the effectiveness of the generated data sets. Results and Discussion: The consistent comparison of the simplified approach and Monte Carlo simulation results show the effectiveness and advantage of applying the data set to a quick shielding design and conservative dose assessment for proton therapy facilities. Conclusion: This study has expanded the existing Monte Carlo-based data set to allow the simplified approach method to be used for dose assessment or shielding design for beam services in proton therapy facilities. It should be noted that the default model of the MCNP6 is no longer the Bertini model but the CEM (cascade-exciton model), therefore, the results of the simplified approach will be more conservative when it was used to do the double confirmation of the final shielding design.

• Computers and Concrete
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• 제33권6호
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• pp.689-706
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• 2024

This study is aimed at identifying structural element stiffness influence on vertical earthquake response of mid-rise R/C frame buildings. To this aim, a mid-rise RC building structure is designed as per the new Turkish Seismic Code for Buildings-2018, and 3D FE model of the building is established. Based on the established FE model, a total number of six buildings are considered depending on certain percentage increase in beam, slab, and column. The time-history response analyses (THA) are performed separately for only horizontal (H) and horizontal +vertical (H+V) earthquake motions to make a comparison between the load cases. The analysis results are presented comparatively in terms of the monitoring parameters of the base overturning moment (M_o), the top-story lateral displacement (d_L) and the top-story vertical displacement (d_V). The obtained results reveal that the base overturning moment and the top-story vertical displacement are affected by vertical earthquake motion regardless of the increase in the dimension of beam, slab, and column. However, vertical earthquake motion is not effective on the top-story lateral displacement due to no change between H and H+V load. The dimensional increase in either slab or beam leads to a considerable increase in the base overturning moment and the top-story vertical displacement while causing decrease in the top-story lateral displacement. In addition, the dimensional increase in column has a positive effect on the decrease in the monitoring parameters of the base overturning moment (M_o), the top-story lateral displacement (d_L) and the top-story vertical displacement (d_V).

• 한국전기전자재료학회논문지
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• 제13권6호
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• pp.526-532
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• 2000

The paste on the glass or fabrication of the PDP(Plasma Display Panel) barrier rib was selectively etched using focused A $r_{+}$ laser(λ=514 nm) and Nd:YAG(λ=532, 266 nm) laser irradiation. The depth of the etched grooves increase with increasing a laser fluence and decreasing a laser beam scan speed. Using second harmonic of Nd:YAG laser(532 nm) the etching threshold laser fluence was 6.5 mJ/c $m^2$ for the sample of PDP barrier rib. The thickness of 180 ${\mu}{\textrm}{m}$ of the sample on the glass was clearly removed without any damage on the glass substrate by fluence of 19.5J/c $m^2$beam scan speed of 20${\mu}{\textrm}{m}$ /s. In order to increase the etch rate of the barrier rib material barrier rib samples heated by a resistive heater during laser irradiation. The heated sample has many defects and becomes to be fragile. This imperfection of the structure compared to the sample without heat treatment allows the effective etching by the focused laser beam. The etch rates were 65${\mu}{\textrm}{m}$/s and 270 ${\mu}{\textrm}{m}$/s at room temperature and 20$0^{\circ}C$, respectively.y.

• Current Optics and Photonics
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• 제1권3호
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• pp.207-213
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• 2017

The Adaptive Front-lighting System (AFS) is a part of the active safety system, providing optimized vision to the driver during night time and other poor-sight conditions of the road by automatic adaptation of lighting to environmental and traffic conditions. Basically, an AFS provides four different modes of the passing beam as designated in an United Nations Economic Commission for Europe regulation (ECE324-R123): neutral state or country light (Class C), urban light (Class V), highway light (Class E), and adverse weather light (Class W). In this paper, we first present an optics design for an AFS system capable of producing the Class C/V/E/W patterns requiring only on/off modulation of multi-array LEDs with no need for any additional mechanical components. The AFS optics consists of two separated modules, cutoff and spread; the cutoff module lights a narrow central area with high luminous intensity, satisfying the cutoff regulation, and the spread module forms a wide spread beam of low luminous intensity. Each module consists of two major parts; the first converts a discretely positioned LED array into a full-filled area emitting light source plane, and the second projects the light source plane to a 25 m away target plane. With the combination of these two optics modules, the four beam patterns are formed by simple on/off modulation of multi-array LEDs. Then we report the development of a prototype that was demonstrated to provide the four beam patterns.

• 한국지진공학회논문집
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• 제27권3호
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• pp.129-137
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• 2023

This study presents a dry precast concrete (PC) beam-column connection, and its target seismic performance level is set to be emulative to the reinforced concrete (RC) intermediate moment resisting frame system specified in ACI 318 and ASCE 7. The key features include self-sustaining ability during construction with the dry mechanical splicing method, enabling emulative connection performances and better constructability. Test specimens with code-compliant seismic details were fabricated and tested under reversed cyclic loading, which included a PC beam-column connection specimen with dry connections and an RC control specimen. The test results showed that all the specimens failed in a similar failure mode due to plastic deformations in beam members, while the hysteretic response curve of the PC specimen showed comparable and emulative performances compared to the RC specimen. Seismic performance evaluation was quantitatively addressed, and on this basis, it confirmed that the presented system can fully satisfy all the required performance for the intermediate RC moment resisting frame.

• 한국구조물진단유지관리공학회 논문집
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• 제19권2호
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• pp.151-159
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• 2015

본 연구에서는 기존 철근콘크리트 구조물 보-기둥 접합부의 내진성능의 개선을 위해 보-기둥 접합부 영역을 FRP보강재 (탄소섬유시트, 아라미드섬유시트, 매입형 CFRP Rod)를 사용하여 보강한 후 내진성능을 평가하였다. 총 7개의 실험체를 제작하고 실험을 수행하여 내진성능을 평가하였으며, 본 연구의 실험결과를 근거로 다음과 같은 결론을 얻었다. 기존 철근콘크리트 보-기둥 접합부의 접합부 영역을 보강한 결과, 초기 재하시 접합부 영역의 균열억제 효과와 재하 전 과정을 통하여 보강재의 구속효과로 인하여 균열억제 효과가 커서 안정적인 파괴형태 및 내력향상 효과를 나타내었다. 매입형 CFRP Rod와 탄소섬유시트를 활용한 R/C 외부 보-기둥 접합부 실험체 LBCJ-CRUS는 표준실험체 LBCJ와 비교하여 변위연성 4, 7에서 각각 최대내력은 1.54배, 에너지소산능력은 2.36배 증가하였다. 그리고 실험체 LBCJ-CS, LBCJ-AF시리즈는 변위연성 7에서 표준실험체 LBCJ 보다 에너지소산능력이 각각 2.04~2.34, 1.63~3.02배 증가하였다.

• 대한토목학회논문집
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• 제14권3호
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• pp.439-452
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• 1994

본 논문에서는 동적하중을 받는 철근 콘크리트 뼈대구조의 경비 최적설계방법과 한계상태 설계 최적화 알고리즘을 제시하였다. 뼈대구조의 동적반응은 모드 중첩법을 이용하여 해석하였으며 뼈대구조의 각 부재를 두 개 이상의 요소로 구성하여 각 요소의 절점에서는 축방향, 횡방향 및 휨방향의 거동을 규명할 수 있도록 3 d.o.f(자유도)로 구성된 강성 매트릭스와 질량 매트릭스를 사용하였다. 철근과 콘크리트의 주 재료 경비로 유도한 목적함수는 한계 상태 설계 규정에 따라 철근 콘크리트 뼈대구조의 역학적 거동의 문제와 사용성 제약조건을 만족하면서 최적화를 이루도록 하였다. 목적함수와 제약조건은 단면의 유효깊이, 보의 폭, 인장과 압축 철근의 단면적, 기둥의 전단 철근 단면적들의 설계변수로 유도하였으며 최적화 문제를 형성하였다. 몇가지 예제를 통하여 동적거동을 고려한 철근 콘크리트 뼈대구조의 자동화된 최적 설계 알고리즘의 가능성, 타당성 및 효율성을 검토하였다.