• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.420-422
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• 2004

This paper reports the results of performance verification tests of the base isolated RC building with the laminated rubber bearings which is manufactured by Dongil Rubber Belt Co.. The shaking table tests were performed using a scaled 3-story model scaled to 1/3 of the prototype RC apartment building. Several major earthquake records were scaled to different peak ground accelerations and used as input base excitations. Through the verification tests, the validity of the applied base isolation device and the response reduction effect against earthquakes are confirmed.

• Journal of Biosystems Engineering
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• 제30권4호
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• pp.220-228
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• 2005

This study was conducted to investigate the main factors that contain a rotating velocity ratio between wheel and conveyor belt, a tilt angle of conveyor belt and a rotating velocity of a dick cutter for mechanization of Chinese leek harvest. In the survey on the cultivation of Chinese leek, row spacing of 350 m and cutting height of 10 mm from the ground were set up for field tests. Test equipment was designed to cut, pick up and convey Chinese leek one row by one row. From the results of material tests, pick-up height of conveyor belt was set up at $60\~90m$ from the bottom, and the strain and stress at rupture of Chinese leek was 0.487 m/m and 0.01078 MPa. An elastic coefficient of the rubber (Neoprene) of conveyor belts was 1.1077 under the strain of 0.3 nym. from the results of field tests, the tilt angle of conveyor belt was the range of $25^{\circ}\~30^{\circ}$ under consideration far space of container, the velocity ratio between vehicle and conveying belt was 1 to 2.4~1.7 at 0.1~0.3 m/s of vehicle, and optimum rotating velocity of the disk cutter was 34.8 m/s or more under consideration for soil friction.

• 한국공작기계학회논문집
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• 제12권2호
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• pp.59-64
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• 2003

Continuously Variable Transmission (CVT) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The main advantages of the U with V-belt, which has been Popular in Asia, are a simple mechanism less maintenance and low cost. One of the important factors which have an influence on the performance of the CVT is change of axial distance. Base on an experiment the effects of transfer torque and speed ratio of both driving pulley and driven pulley during the alteration of axial distance were studied.

• 한국생산제조학회지
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• 제20권4호
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• pp.376-381
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• 2011

CVT(Continuously Variable Transmission) is one of the most promising candidates for the future automobile transmission because of its continuously variable gear ratio and reduced shift shock. It is also possible to operate the power source at its high efficiency region with CVT. The CVT system consists of thrust plate, driving pulley, belt, driven pulley, and preload spring of output shaft. In this paper, the dynamic modeling of a CVT system is completed to obtain the static performances of CVT system. A simulator is implemented on Matlab(Simulink), which can analyse the static performances of a CVT system. The methods for improving the total efficiency of a motorcycle system are also proposed based on the simulation results. In this study we increase the capacity factor of CVT up to the three times of default specification.

• Macromolecular Research
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• 제17권10호
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• pp.776-784
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• 2009

N,N-dimethyldodecylamine (tertiary amine)-modified MMT (DDA-MMT) was prepared as an organically modified layered silicate (OLS), after which styrene-butadiene rubber (SBR) nanocomposites reinforced with the OLS were manufactured via the latex method. The layer distance of the OLS and the morphology of the nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). By increasing the amount of N,N-dimethyldodecylamine (DDA) up to 2.5 g, the maximum values of torque, tensile strength and wear resistance of the SBR nanocomposites were increased due to the increased dispersion of the silicate layers in the rubber matrix and the increased crosslinking of the SBR nanocomposites by DDA itself. When SBR nanocomposites were manufactured by using the ternary filler system (carbon black/silica/OLS) to improve their dynamic properties as a tire tread compound, the tan $\delta$(at $0^{\circ}C$ and $60^{\circ}C$) property of the compounds was improved by using metal stearates instead of stearic acid. The mechanical properties and wear resistance were increased by direct substitution of calcium stearate for stearic acid because the filler-rubber interaction was increased by the strong ionic effect between the calcium cation and silicates with anionic surface. However, as the amount of calcium stearate was further increased above 0.5 phr, the mechanical properties and wear resistance were degraded due to the lubrication effect of the excessive amount of calcium stearate. Consequently, the SBR/organoclay nanocomposites that used carbon black, silica, and organoclay as their ternary filler system showed excellent dynamic properties, mechanical properties and wear resistance as a tire tread compound for passenger cars when 0.5 phr of calcium stearate was substituted for the conventionally used stearic acid.

• Korean Chemical Engineering Research
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• 제47권4호
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• pp.403-409
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• 2009

1906년 George Oenslager에 의해 처음으로 아닐린계 유기 가황 촉진제를 발견한 이 후 현재 많은 종류의 유기 가황 촉진제가 알려져 있으며 이들 유기 가황 촉진제를 그 특성에 맞도록 병용하면 더욱 효과적이고 이것을 2종 혹은 3종을 병용하면 또 다른 효과를 나타낸다. 최근 고무 산업의 많은 분야에서 생산성 향상 및 제조환경 개선 요구에 부응하기위하여 사출 기법이 도입되고 있으며 이를 위해서 고속 가류형 고무 컴파운드의 개발이 요구되고 있다. 따라서 적절한 가류 시간 확보를 위하여 다양한 종류의 촉진제에 대한 연구, 컴파운드의 적절한 저장 안정 기간 확보에 대한 연구, pellet 형상 제조 시 자중에 의한 autoadhesion 감소에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 NR/BR compounds에 MBTS(2,2' Dithiobisbenzothiazole), TMTM(Tetramethylthiuram Monosulfide), ZDMC(Zinc dimethyldithiocarbamate), CBS(N-Cyclohexyl benzothiazolyl-2-sulfenamide), DPG(Diphenylguanidine)를 각각 병용하여 가황 고무의 가황 특성 및 기계적 물성을 비교 분석하였다. 촉진제 병용에 따른 NR/BR compounds를 평가한 결과 MBTS 1.5 phr, TMTM 0.5 phr, DPG 0.15 phr을 사용한 경우 가장 우수한 가황 특성($t_{90}$: 235 sec, $T_{max}$: 5.77 Nm)을 나타내었으며 100, 300% 모듈러스 및 인열 강도 값이 각각 2.180, 5.656 MPa, 59.58 kgf/cm으로 가장 우수한 결과를 나타내었다.

• 한국기계기술학회지
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• 제13권2호
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• pp.129-135
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• 2011

Dry CVT(Continuously variable transmission) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The movable flange of the driving pulley has the centrifugal roller and a ramp plate in the flange. The movable flange moves toward a fixed flange under the actuation of a centrifugal roller, as the driving pulley speed increases. The main advantages of the Dry CVT with V-belt, which has been popular in Asia, are a simple mechanism, less maintenance and low cost. The important claim which have an influence on the performance of the Dry CVT is the wear of the centrifugal roller. In this study ball type is proposed instead of roller type of movable flange to resolve claim. Also experiments are carried out for new model to evaluate performances.

• 복식
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• 제64권8호
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• pp.83-96
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• 2014

This study aims to analyze the design of current nurse uniforms, investigate the state of nurse uniforms, and uniform design preferences in order to ultimately develop functional nurse uniform, which satisfy their needs. First, observing photos of nurses' campaign on wearing a badge showed that opening of top uniform almost always incorporated buttons, and sleeves were mostly set-in half sleeves while collars tended to be mandarin collars. The colors were mostly white for both top and bottom, while the top showed a bit more variety in colors. White tops often incorporated hospital logos on them. Second, in terms of the nurse uniform distribution, each nurse is given one top and one bottom per year. In addition, either a cardigan or a jacket on top of the regular summer uniform constitutes the winter uniform, whereas the availability of cardigans differed by hospitals. Third, the main source of contamination of uniforms was blood, and the level of satisfaction was all low in terms of the design, function, and material of the uniform, calling for the enhancement and development of new uniforms. Design preferences were two-piece with pants, color preferences were blue and pink, and pattern preferences were hospital logo, stripes, and check patterns in the listed order of preference. Complaints were usually made on the contamination of front pocket of the top, lack of sufficient pockets for storage, and tightness of the sleeves. Some preferences on finishing were the princess seams, mandarin collar, set-in half sleeves, and button closing on top. The preferred belt was a mixed form of straight-lined belt and rubber belt, and straight lined hem and spandex blended fabrics were favored for the clothing.

• Elastomers and Composites
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• 제7권2호
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• pp.239-246
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• 1972

이제까지 polyurethane 탄성체(彈性體)에 대한 새로운 연구분야(硏究分野)와 급속(急速)히 변화(變化)되어 가고 있는 polyurethane 제품(製品)의 응용면(應用面에) 대해 알아보았다. 예(例)의 대부분(大部分)은 미국(美國)의 Goodyear tyre & Rubber Co 연구소(硏究所)에서의 연구(硏究) 및 개발(開發)된 것을 기본(基本)으로 하였다. 자동차(自動車)의 내부부분(內部部分), 특히 Crashpad 및 기타 내부부분(內部部分), 고무제자동차(製自動車) bumper의 가능성(可能性), solid tyre, 연료용기(燃料用器) 정지용 belt 장치(裝置), 접착제(接着劑), 고무 Roll, 통풍용치차(通風用用齒車), 진동통(振動桶)과 흥미(興味)진진한 응용면(應用面)에 관한 다른 분야(分野)에 관(關)한 응용(應用)을 검토(檢討)하였다. 화학약품(化學藥品)의 저항성혹(抵抗性或)은 비저항성(非抵抗性)을 가진 새로운응용의 개발(開發)이 urethanr 응용(應用)의 새로운 길을 넓게 열어 놓았다. 합성피혁(合成皮革)과 피혁(皮革)의 Coating 물(物)은 완전(完全)이 polyruethane 기술(技術)에 기초(基礎)를 두게되었다. 특유(特有)한 혼합기기(混合機械)의 개발(開發)은 가격(價格) 및 질(質)에 커다란 영향을 미치게 될 것이다. polyurethane 연구(硏究)의 흥미(興味)있는 분야(分野)는 인공기관(人工器官)에 관(關)한 의학적(醫學的)인 연구(硏究)이다. 우리들이 장래(將來)를 내다볼적에 융통성(融通性) 있는 polyurethane 탄성체(彈性體의) 응용(應用)은 아직도 개발(開發)될 여지가 많이 남아있다는 것을 쉽게 예측할 수 있다. 그 이유(理由)는 polyurethane의 구조적(構造的) 특성(特性), 성능(性能)및 응용(應用)의 가능성(可能性) 및 그의 양식(樣式)이다.

• Composites Research
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• 제16권3호
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• pp.9-17
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• 2003

타이어 벨트층내의 코드간 균열연결 및 층간균열진전을 모사하기 위해 자유단을 갖는 2층 고무/코드 적층시험편에 대한 4~11mm 변위제어 실험을 수행하였다. 자유단의 코드간 균열연결시의 폭방향 균열진전량은 45$^{\circ}$ 경사진 코드들간 길이의 절반에 도달할 때의 측정값으로 하였으며, 이는 탐침법에 의해 측정되었다 또한, 자유단에서 코드들간 균열연결을 모사하기위해 2차원의 이상화된 모델링 기법을 고안하였다. 이론수명은 테어링에너지(균열파단면의 단위면적당 방출에너지)를 이용하여 코드간 균열연결수명(임계값)과 이후 최종파손까지의 수명으로 구분하였으며, 이들을 각기 실험값과 비교하였다. 임계값까지의 수명예측은 실험과 비교하여 약 20%, 최종파손까지 약 65%의 오차가 발생하였다. 따라서, 전체 이론수명은 실험과 비교하여 약 45%의 오차를 발생하였다.