http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
성숙도 방법을 이용한 불포화 폴리에스터 수지 폴리머 콘크리트의 압축강도 예측
최기봉,김남길,이윤수,연규석,Choi, Ki-Bong,Jin, Nan Ji,Lee, Youn-Su,Yeon, Kyu-Seok 한국농공학회 2017 한국농공학회논문집 Vol.59 No.6
This study investigated to predict the compressive strength of unsaturated polyester resin based polymer concrete using the maturity method. The test results show that the development of the compressive strength increased exponentially until an age of 24 hours. After 24 hours, the development of the compressive strength just increased gradually. This test result shows that the strength of unsaturated polyester resin based polymer concrete was developed mainly at the early age. Estimated datum temperature of unsaturated polyester resin based polymer concrete was $-20.67^{\circ}C$ which was much lower than of datum temperature ($-10^{\circ}C$) of Portland cement concrete. Also, this study result shows that the existing maturity index associated with Portland cement concrete was not applicable for polymer concrete because curing time of Portland cement concrete is different clearly with curing time of polymer concrete. The cause of different curing time was that there were different curing mechanisms between Portland cement concrete and polymer concrete. In order to best apply the experimental data to a model, CurveExpert Professional, the commercial software, was used to determine the predictive model regarding the compressive strength of unsaturated polyester resin based polymer concrete. As a result, Gompertz Relation or Weibull Model was an appropriate model as a predictive model. The proposed model can be used to predict the compressive strength, especially, it is more useful when the maturity is in the range between $40^{\circ}C{\cdot}h^{0.4}$ and $900^{\circ}C{\cdot}h^{0.4}$.
자기력을 이용한 비접촉 6자유도 미소위치결정 기구의 개발-설계, 모델링 및 제어-
최기봉,박기환,김수현,곽윤근,Choi, Kee-Bong,Park, Kyi-Hwan,Kim, Soo-Hyun,Kwak, Yoon-Keun 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.4
A magnetically levitated micro-positioner is implemented to avoid mechanical friction and increase precision. Since magnetic levitation system is inherently unstable, most concern is focused on a magnetic circuit design to increase the system dynamic stability. For this, the proposed levitation system is constructed by using an antagonistic structure which permits a simple design and robust stability. From the dynamic equations of motion, it is verified that the proposed magnetically levitated system is decoupled in 6 degree-of-freedom motion. Experimental results are presented in terms of time response and accuracy.
최기봉,윤희주,차승희,최정도 ( Ki Bong Choi,Hee Ju Youn,Seung Hee Cha,Jung Do Choi ) 한국센서학회 1997 센서학회지 Vol.6 No.5
Fiber-optic evanescent wave sensor was designed and fabricated to detect mouse immunoglobulin G(IgG) with decladed optical fiber on which anti-mouse IgG was immobilized. A sensitivity obtained by any direct or competitive method was lower than 1 ㎍/㎖. Anti-mouse IgG was immobilized on 93.9% of core surface of optical fiber by simple adsoption method. The effect of postcoating using bovine serum albumin to remove non-specific binding was not observed. As the ratio of fluorescein to mouse IgG increased, the fluorescence signal increased, but that increase showed no linear relationship. Our fiber--optic sensor system could be used as immunosensor by measuring evanescent fluorescence in antigen-antibody reaction with good sensitivity below lug/mP level.
미세 부품 조작을 위한 탄성힌지 기반 압전소자 구동형 초정밀 머니퓰레이션 시스템
최기봉(Kee-Bong Choi),이재종(Jae Jong Lee),김기홍(Gee Hong Kim),고국원(Kuk Won Ko) 제어로봇시스템학회 2009 제어·로봇·시스템학회 논문지 Vol.15 No.9
This paper presents a manipulation system consisting of a coarse/tine XY positioning system and an out-of-plane manipulator. The object of the system is to conduct tine positioning and manipulation of micro parts. The tine stage and the out-of-plane manipulator have compliant mechanisms with flexure hinges, which are driven by stack-type piezoelectric elements. In the fine stage, the compliant mechanism plays the roles of motion guide and displacement amplification. The out-of-plane manipulator contains three piezo-driven compliant mechanisms for large working range and fine resolution. For large displacement, the compliant mechanism is implemented by a two-step displacement amplification mechanism. The compliant mechanisms are manufactured by wire electro-discharge machining for flexure hinges. Experiments demonstrate that the developed system is applicable to a fine positioning and tine manipulation of micro parts.
3차원 미세형상 측정용 탄성힌지 기반 압전구동식 격자 스캐너
최기봉(Kee-Bong Choi),텐 알렉세이 대성(Aleksey-Deson Ten),이재종(Jae Jong Lee),김성현(Sung-Hyun Kim),고국원(Kook Won Ko),권순기(Soon Ki Kwon) 제어로봇시스템학회 2009 제어·로봇·시스템학회 논문지 Vol.15 No.8
This paper proposes a grating scanner which is driven by a stack-type piezoelectric element. The mechanism of the grating scanner is based on flexure hinges. Using some constraints, the compliant mechanism is designed and then verified by Finite Element Analysis. The designed compliant mechanism is manufactured by wire electro-discharge machining, and then integrated with a stack-type piezoelectric element for actuation and a capacitance displacement sensor for measuring ultra-precision displacement. Experiments demonstrates the characteristics and the performances of the grating scanner using the terms of working range, resonance frequency, bandwidth and resolution. The grating scanner is applicable to a Moire interferometry for measuring 3-dimensional microscopic surface.
바잘트섬유 시트로 전단보강한 철근콘크리트 보의 전단경간비에 따른 거동특성
최기봉 ( Choi Ki-bong ) 한국복합신소재구조학회 2021 복합신소재구조학회논문집 Vol.12 No.6
이 연구는 바잘트 섬유시트로 전단보강한 철근콘크리트 보의 전단경간비에 따른 구조물의 구조적 거동을 실험을 통해 확인하였다. 철근콘크리트 보의 전단보강은 무보강, 45도, 90도, U형보강을 변수로 두었으며 전단경간비에 따른 실험결과 U형으로 보강하였을 때 철근콘크리트 보의 전단보강효과가 높음을 확인하였다. In this study, the structural behavior of reinforced concrete beams shear-strengthened with basalt fiber sheets based on the shear span ratio was investigated via experiments. The experimental parameters for the shear strengthening of reinforced concrete beams comprised beams without reinforcement and 45°, 90°, and U-shaped reinforcements. Experimental results showed that the shear strengthening effPect of the reinforced concrete beams was excellent when the basalt fiber sheet was subjected to U-shape reinforcement.
다방향성 바잘트 섬유 시트로 전단보강한 철근콘크리트 보의 전단성능
최기봉 ( Choi Ki-bong ) 한국복합신소재구조학회 2022 복합신소재구조학회논문집 Vol.13 No.5
이 연구는 다방향성 바잘트 섬유 시트로 보강한 철근콘크리트 보의 보강방법에 따른 전단거동을 실험을 통해 확인하였다. 실험변수는 보강방법(무보강, 45도 90도 U형)과 보강겹수(0, 1 2겹)를 변수로 두었으며 전단강도실험결과 바잘트섬유시트를 90도로 1겹 보강하였을 때 최대 11% 이상의 보강성능을 확인하였다. 또한, 유효변형률을 검토한 결과 섬유양이 증가함에 따라 유효변형률이 감소함을 확인하였다. The shear behavior according to the reinforcement method of concrete beams reinforced with multidirectional basalt fiber sheets was verified through experiments. The experimental parameters were the reinforcement method (non-reinforcement, 45°, 90°, and U-shaped) and the number of reinforcement layers (0, 1, and 2 layers). The shear strength test revealed an up to 11% increase in shear performance when a basalt fiber sheet was used as reinforcement in a single layer at 90°. Additionally, the effective strain decreased as the amount of FRP was increased.
보수/보강된 구조물의 건전도 평가기술 - CFS로 휨보강된 철근콘크리트 보의 보강성능 및 음향방출 특성 평가 : 보수/보강된 구조물의 건전도 평가기술
최기봉(Choi Gi-Bong),최창식(Choi Chang-Sik),서수연(Seo Soo-Yeon),윤현도(Yun Hyun-Do) 한국구조물진단유지관리학회 2006 한국구조물진단학회 학술발표회논문집 Vol.10 No.1
As time goes up, structural capacity of members decreases in R/C structures. The deterioration of the capacity is mainly due to the corrosion of materials, environmental pollution, etc. Thus it is necessary to develop the method for repair and retrofit of structures in order to ensure structural safety of members. Recently, a method using Carbon Fiber Sheet (CFS) has been widely recognized as good one for strengthening members. Several flexural tests for beam strengthened with CFS show that CFS of the beam is ripped by tension or separated from the concrete face at failure. The ultimate strength of the beam, also, depends on those failure patterns. The flexible capacity of RC members retrofitted with CFS depends on bond capacity between concrete and CFS. Experimental and analytical works are performed to develop an integrity Evaluation of repaired/strengthened RC structure. From a test, damage information for strengthened structure with CFS investigated and the estimation method structural capacity by using the damage information is developed. And an analysis is carried out to predict nonlinear behavior of RC member retrofitted by CFS and analysis result is compared with test result to verify the usefulness of it.