• Computers and Concrete
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• 제16권6호
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• pp.909-918
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• 2015

This paper presents an experimental study for determining the bond performance of lightweight concretes produced using pumice aggregate coated with colemanite-cement paste. For this purpose, eight hinged beam specimens were produced with four different concrete mixtures. 14 mm deformed bars with $10{\Phi}$ development lengths were selected constant for all test specimens. All the specimens were tested in bending and load-slip values were measured experimentally to determine the effect of colemanite-cement coated pumice aggregate on bond performances of lightweight concretes. Test results showed that, colemanite-cement coated pumice aggregate increases compressive strength and bond performance of the lightweight concretes, considerably.

• Asian Journal of Innovation and Policy
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• 제4권3호
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• pp.328-359
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• 2015

To explain the performance gap between firms in the same industry, this study focuses on innovation. It provides a new framework using the dynamic-capability view based on empirical analysis of domestic businesses. The findings of this study are as follows: First, when the uncertainty and competition intensity in the business environment and the level of innovation have “fit”, it means that when the former goes up, so does the latter. In this regard, when the innovation capability of a firm is high, being “fit” means that the level of innovation is also high. When there was fitting innovation on industrial environment and innovation capacity, companies were able to achieve relatively high performance. Also, it was confirmed that instead of innovation for innovation capacity, innovation for industrial environment led to relatively higher performances of firms.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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• pp.318-321
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• 2005

한국항공우주연구원에서는 55kW급 마이크로 터빈용 엔진에 사용되는 저공해 예혼합 연소기를 개발하였다. 연소기는 역류-캔 형 연소기로써 항공우주연구원에서 설계, 해석 제작 및 시험을 수행하였으며 최종 시험결과, 연소효율 $99.5\%$, NOx 10ppm 미만, Pattern Factor $30\%$이하. 압력 손실 $4\%$이하의 성능을 확인하였다.

• 한국항만경제학회지
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• 제21권4호
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• pp.255-274
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• 2005

To acquire a port traffic, governments in North-East Asia have intensively invested port development. Furthermore, the major shipping company directly make a call at northern chinese ports like Qingdao, Dalian and Tianjin. Those changes of port environment will have a considerable effect on a port traffic in Korea. In order to prepare against those changes, it is necessary to estimate a port traffic in Korea A port traffic in Korea is estimated by the use of explanation variables like GDP of Korea, real effective exchange rate, world economic performances and the trade in China, et al. When GDP in Korea goes up 1%, it is estimated that container port traffic of all ports and Pusan Port is upward $1.0{\sim}1.2%$ and $0.8{\sim}0.9%$ respectively. When the trade in China goes up 1%, it is estimated that Container transshipment is upward $1.6{\sim}1.7%$ approximately.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권1호
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• pp.33-39
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• 2005

In this paper, we propose a slider servo-mechanism driven by electro-magnetic actuator to improve straightness of linear motor stages. Based on axial-position dependent deterministic characteristics of the straightness error, a feedforward compensation control is appled to reduce the straightness error. In the consideration of uncertain properties of friction and its effects on positioning accuracy, a sliding mode control is applied. The effectiveness of the suggested mechanism and the control performances are illustrated along with some experimental results.

• 전기의세계
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• 제21권3호
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• pp.41-47
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• 1972

The requirements of a successful design for single phase induction motors with a high efficiency have, in recent years, led to the use of non-quadrature stator windings motors in which a high starting torque is a prime requisite. The capacitor motor is one of above machines in which various possible forms of asymmetry can be occur. These forms of asymmetry in the stator phase windings, encountered in machine designs, are 1) an asymmetrical disposition in space of their magnetic axes, 2) a difference in their effective number of turns, 3) a difference in the distribution of their coil groups per pole and 4) amounts of capacitance of an auxiary winding. In order to apply the effective performance prediction of these form to motors, mading of lower quality-domestic magnetic materials, the analysis and the experimental investigations of its sample motors are described in this paper. The utility of such a motor is demonstrated and it is shown that the effects- a good efficiency, good power factor and high starting torque-of the motor mechanism with non-quadrature stator phase windings can development disadvantages by using the lower quality-domestis magnetic materials.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1514-1519
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• 1999

This paper presents two flexible alternatives to the decoupled load flow(DCL) method. The proposed load flow methods can improve the convergence profiles of the DCL by reflecting in part the effects of the off-diagonal terms in the Jacobian at minimal costs. They can improve the convergence characteristics especially when the power system operating states deviate from the conditions required for stable convergence of the DCL and the P-Q coupling becomes significant. Two algorithms are obtained from the expression of the full Newton-Raphson load flow (NRL) method by successively diminishing the effects of the off-diagonal submatrices in the Jacobian. In the process of simplification, the Neuman series expansion is utilized. Test results show promising performances of the proposed algorithms in their convergence characteristics both in number of iterations and overall convergence speeds. Proposed algorithms are expected to provide flexible alternatives to the NRL when the DCL experiences convergence problems.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.827-828
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• 2001

이 실험은 특정 DNA를 검출 할 수 있는 새로운 방법을 제시하고 개발하려는 것이다. 이것은 geno-chromatography 분석방법이라고 하여 DNA capture probe를 membrane상에 고정하고 PCR을 통하여 증폭된 특정 유전자를 hybridization 반응을 이용하여 탐지하는 것이다. 이러한 개념을 식중독균의 일종인 Salmonella 균의 탐지에 적용하여 그 분석시스템의 성능을 확인 할 수 있었다.

• 한국광학회지
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• 제4권2호
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• pp.145-156
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• 1993

고화질 프로젝션 TV에서 광학부품들이 가격 및 성능면에서 경쟁력을 갖춘 최적의 시스템을 설정하고, 그로부터 현재 방송규격인 NTSC 및 향후에 시행될 HDTV에 공용적용할 투사렌즈를 설계 개발하였다. 3차 수차가 모두 보정된 초기설계치, 프라스틱 렌즈의 비구면화, 공차 및 제작성을 고려한 최적화 설계, 그리고 온도보상등의 과정을 통해 설계 제작된 렌즈의 구현가능한 화면크기는 40∼55인치, 해상도는 1000TV-line 이상이다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.19-22
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• 2003

In this paper are described the indirect induction heated boiler and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter which can operate in the frequency range from 20 [kHz] to 50 [kHz]. A specially designed induction heater, which is composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates, is inserted into the ceramic type vessel with external working coil. This working coil is connected to the inverter and turbulence fluid through this induction heater to moving fluid generates in the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from a practical point of view.