• 한국철도학회논문집
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• 제13권5호
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• pp.528-534
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• 2010

신성장이론에서 R&D Stock은 노동과 자본 외에 제3의 생산요소이다. 이 관점에서 R&D Stock은 기존의 자본처럼 비용이 투입되어야만 축적이 가능한 자본의 위치를 차지하게 되며 이것을 지식자본이라고 한다. 이러한 지식자본을 향상시키기 위한 노력이 R&D투자이며 이의 축적이 R&D Stock이다. R&D Stock과 총요소생산 성과의 관계를 추정함으로써 경제성장의 기여도, R&D 투자의 수익률 등을 분석한다. 본 논문에서는 철도 R&D 투자에 대한 R&D Stock을 분석하고 기술수준과 비교 한 결과 R&D Stock이 증가하면 기술수준도 비례적으로 증가되었다. 그리고 GDP에 대한 철도산업의 비중과 전 부문에 대한 철도 R&D Stock 비중을 비교한 결과 철도산업의 비중에 비해 철도 R&D Stock 비중이 상대적으로 작아 지속적인 철도 R&D 투자가 필요함을 알 수 있다.

• 품질경영학회지
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• 제46권3호
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• pp.551-568
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• 2018

Purpose: This study addressed the relationship between technological innovation activity and management efficiency of Korean automobile firms. We tested the hypothesis of non-liner relationship of innovation activity in relation to management efficiency. Methods: We discussed prior literature in the firm innovation strategy and management efficiency studies to provide better understanding of relationships between technological innovation activity and management efficiency. As a result, we developed develop and tested a model (Inverted-U shaped) capturing the non-linear impact of technological innovation activity. While we used R&D expenditure and patent registration data for measuring firms' innovation activity, management efficiency was evaluated by using DEA(Data Envelopment Analysis). Results: Main findings of our empirical analysis indicated that the relationships between technological innovation activity and management efficiency was inverted U shaped. This implied that the relationship between technological innovation and management efficiency is inverted U-shaped non-linear, with management efficiency increasing up to a point, beyond which higher levels of R&D and patent registration activities led to a decrease in management efficiency. Conclusion: This study empirically assessed the inconclusive findings of previous research in the area of effects of innovation activities in relation to firm performance. The paper also provided theoretical and practical implications for firms who explore efficient strategy to promote the management performance through technological innovation activities. Future research directions with the limitation of the study was discussed.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1995년도 제47차 추계 학술대회 연제집
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• pp.283-284
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• 1995

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.481-486
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• 1997

In the paper, a simplified method for nonlinear analysis of reinforced concrete structures is presented, which is based on timeoshenko beam theory and constitutive equations that are given by the relation of average stress and average strain for concrete and reinforcing bars. Especially, this method consider shear deformation and determine the failure mode. In this paper, 1-D beam element model and program considering shear deformation are suggested. In addition, program procedure is presented briefly and the results are plotted with test examples.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.814-817
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• 2015

A new ionic mass transfer correlation is derived for the fluid-saturated, horizontal porous layer. Darcy-Forchheimer model is used to explain characteristics of fluid motion. Based on the microscales of turbulence a backbone mass transfer relation is derived as a function of the Darcy-Rayleigh number, $Ra_D$ and the porous medium Schmidt number, $Sc_p$. For the Darcy's limit of $Sc_p{\gg}Ra_D$, the Sherwood number, Sh is a function of $Ra_D$ only. However, for the region of high $Ra_D$, Sh can be related with $Ra_DSc_p$. Based on the present backbone equation and the electrochemical mass transfer experiments which are electro plating or electroless plating, the new ionic mass transfer correlation is suggested in the porous media.

• 한국정밀공학회지
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• 제15권5호
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• pp.153-160
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• 1998

A master-slave system for tele-operation had been developed and tested for several decades. In this paper the master robot is composed of several wires and provides position information of the handle which is driven by a operator within the master robot work space. A PC is used for the command calculation for a slave robot. This paper deals with the relation between the number of strings and D.O.F of the master robot, control method of the slave robot during the operation and the monitoring method over the working area by the computer graphics simulation. The D.O.F of the master robot can be modified by adding or subtracting some strings. The controller of the slave robot uses the advanced PD control method to keep the performance against varying working load.

• Current Optics and Photonics
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• 제1권2호
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• pp.95-100
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• 2017

The transmittance of the three dimensional (3D) transparent display is an important factor and can be enhanced by adding a see-through area to the displayed 3D image in order to transmit an ambient light with maximum transparency. However, there is a side effect that the perceived 3D resolution can be degraded due to the see-through area. In this paper, we propose an advanced method to resolve the above trade-off relation between the transparency and the 3D resolution by using an active parallax barrier (PB) with a see-through area. The experimental results are also presented to prove the proposed principle.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1841-1844
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• 2004

'Mixing Index($D_I$)'s generally used to measure the degree of mixing. A new method to calculate $D_I$ was proposed, when insoluble solution flows in micromixer. 'Vortex Index (${\Omega}_I$)'which indicate the degree of chaotic advection, is defined and formulated. A lots of arbitrary shaped microchannels were tested to calculate the $D_I$ and ${\Omega}_I$. And then a simple algebraic equation, $D_I=A{\Omega}_I+B$, was obtained. This equation may be used instead of partial differential equation, concentration equation.

• Journal of Plant Biology
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• 제23권3_4호
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• pp.91-98
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• 1980

In the present study effects of 2,4-D and kinetin on the callus tissue growth of Korean ginseng(Panax ginseng C. A. Meyer), in relation to the synthesis of saponin were investigated. The saponin synthesis in the callus culture of ginseng root was enhanced by 2,4-D and kinetin. The total saponin content of callus grown on the optima growth conditions, that is, 5mg/l of 2,4-D and 2mg/l of kinetin, was about three times as high as that of the 6 year-old ginseng roots commercially used as herbs. The kinetin specifically increased the synthesis of protopanaxadiol group ginsenoside and decreased the syntehsis of protopanaxatriol gropu in callus cultures, while 2,4-D caused to an increase in the synthesis of protopanaxatriol group ginsenoside and decrease the synthesis of protopanaxadiol group.

• 대한토목학회논문집
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• 제5권1호
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• pp.31-42
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• 1985

비정상(非定常) 침투문제(浸透問題)에서 가장 중요하고 어려운 점은 자유수면(自由水面)의 위치(位置)와 그 변화(變化)를 어떻게 해석(解析)하느냐이다. 그러므로 본(本) 연구(硏究)는 특히 수위상승(水位上昇)에 따른 제체내(堤體內) 침투(浸透)와의 상관계수를 찾았으며(즉, 수위상승에 대해 $V_R=\frac{dH}{dt}$, 침투속도에 대해 $V_S=Ki=k\frac{H-d_1}{d}$), 또한 기(旣) 발표(發表)된 식(式)들을 분석(分析)하여 실험자료(實驗資料)와의 비교 정리(整理) 분석(分析)하였다.