• Title/Summary/Keyword: Theory U

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SangHanUiDam(桑韓醫談) & interchange in ancient oriental medicine between Korea and Japan (『상한의담(桑韓醫談)』과 한일의학문화교류(韓日醫學文化交流))

  • Cha, UngSeok;Kim, NamIl;An, SangU
    • The Journal of Korean Medical History
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    • v.17 no.2
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    • pp.73-98
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    • 2004
  • In this study, we took a look at Joseon's Korean-Japanese Medical Science Cultural Exchange Context through SangHanUiDam(桑韓醫談). SangHanUiDam(桑韓醫談)'s contents mainly include patient treatment and consultations on medical theory, starting from distinguishing medicine. Like the views many scholars that studied Joseon Diplomatic Missionary hold, even in SangHanUiDam(桑韓醫談)'s Medical Science Cultural Exchange, Japan shows great enthusiasm in taking in Joseon's medical culture.

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A New Solar Concentrator Design and Its Characteristics Measurements (태양열 집속기 설계 및 열 특성시험)

  • 황우성;양윤섭
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1998.10a
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    • pp.216-221
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    • 1998
  • Concentrators with concentration ratios between 1.2X-2.0X do not require sun-tracking or seasonal adjustments. Therefor, well designed such a system is more economical as well as abtainable much higher temperature (100-35$0^{\circ}C$) than a flat plate can achieve. In the present study, a 2X tubular concentrator is constructed and tested. The design was based on a new theory. The results of this preliminary study show that its efficiency is 60-70% at the operating temperature range of 80-10$0^{\circ}C$, and the U-value of -3.0 W/$m^2$$^{\circ}C$.

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A Computational Study for Designing Electrical Contacts to MoS2 Monolayers

  • Kim, Hwi-Su;Ha, Hyeon-U
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.478-482
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    • 2014
  • Graphene have renewed considerable interest in inorganic, two-dimensional materials for future electronics. However, graphene does not have a bandgap, it is limited to apply directly to transistors and logic devices. Hence, other layered materials such as molybdenum disulphide ($MoS_2$) have been investigated to address this challenge. Here, we find that the nature of contacts plays a more important role than the semiconductor itself. In order to understand the nature of $MoS_2$/metal contacts, we perform density functional theory electronic structure calculations based on linear combination of atomic for the geometry, bonding, binding energy, PDOS, LDOS and electronic structure. We choose Au as a contact metal because it is the most common contact metal. In this paper, we demonstrate $MoS_2$/Au contacts have a more promising potential in flexible nanoelectronics than $MoS_2$ itself.

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Effects of VHP Positions on the Steering Stability of Agricultural Tractors(I) -Experimental Verification of Safe VHP Positions- (가상(假想) 히치점의 위치(位置)가 트랙터의 조향(操向) 안정성(安定性)에 미치는 영향(影響)(I) -가상(假想) 히치점의 안전(安全) 영역(領域)에 대한 실험적(實驗的) 고찰(考察)-)

  • Shin, S.I.;Kim, K.U.
    • Journal of Biosystems Engineering
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    • v.16 no.3
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    • pp.219-227
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    • 1991
  • This paper concerns with experimental verification of the theory on the safe VHP positions presented in the first part of this study. In the experiment, tillage operation was conducted using a plow mounted to the threepoint hitch and the forces acting on the hitch points were measured. Using the data from the test tractor and plow, computer simualtion was also conducted and its results were compared with those obtained from the field experiment. The comparison showed a reasonable agreement between the two results, by which the theoretical method for the determination of safe VHP positions for steering control can be verified. Some guidelines for expanding the safe VHP region were finally proposed.

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Static VAR Compensator Using 3 Phase PWM converter (3상 PWM 콘버어터에 의한 정지형 무효전력 보상장치의 동작특성)

  • Kim, Cheul-U;Kim, Kwang-Tae;Kwon, Soon-Jae;Hong, Soon-Il
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.137-139
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    • 1988
  • A reactive power compensator whitch employs a three phase voltage source PWM converter is presented and analysed in this study. In this study, instantaneous reactive power compensator by the theory of instantaneous real and imaginary power are theoretically studied how to compensate reactive power occured by fundamental and harmonic reactive current. And we showed the compensation characteristics by comparing the experimental results with those of computer simulation.

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A Study on the Influence factors for Development of Korean IT Service Industry

  • Cho, Nam-Jae;Jung, Jin-Kwan
    • Proceedings of the Korea Database Society Conference
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    • 2008.05a
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    • pp.487-491
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    • 2008
  • After 1990, Korean information technology industry was developed enormously. To estimate these situation, there were many studies such as based on resource based view, transaction cost theory, and so on. These studies were focused on the efforts of company itself and the main body of development were the company not environmental factors. But in developing countries such as Korea, environment which is government policies, other companies, etc. is important factor. So present study estimate the environmental factors for evolution of Korean IT industry with population ecology concept.

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Robust 3-D Points Estimation and Tracking with Dynamic Model for Optical Motion Capture (광학식 동작 포착에서 동적 모델을 이용한 신뢰성있는 3-D 좌표 추정 및 추적)

  • Lee, Dong-Hun;Chu, Chang-U;Kim, Seong-Jin;Jeong, Sun-Gi
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.10
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    • pp.825-834
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    • 2000
  • 광학식 동작 포착(optical motion capture)시스템에서 신뢰할만한 3차원 좌표의 획득과 마커의 궤적 추적은 매우 중요한 문제이다. 3차원 좌표를 획득하기 이해서는 다중의 카메라로부터 2차원의 데이터 간의 대응관계를 구해야 한다. 본 논문에서는 각 카메라에서의 3차원 마커들 간의 대응관계를 k-partite graph로 모델링하고, 릴렉세이션 알고리즘을 사용하여 고스트가 제거된 신뢰성있는 클릭을 추출한다. 이를 통해 정확하고 안정적인 3차원의 좌표를 생성할 수 있다. 또한 추출된 3차원 마커의 궤적의 추적을 위해 칼만 필터를 사용한 마커의 예측과 데이터 연계 문제의 해결을 위한 전략을 제안하고. 사라진 마커의 궤적을 유지시키기 위해 다이나믹 모델을 사용한 추적 알고리즘을 제시한다.

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A New Optical Design and Construction for the High Concentration of Solar Energy (고집적 태양광 집속기의 새로운 광학적 설계 및 개발)

  • Whang, U.S.;Cho, Y.S.;Choo, M.C.;Bulat, L.P.;Yang, Y.S.
    • Solar Energy
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    • v.18 no.3
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    • pp.9-14
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    • 1998
  • The present solar energy concentrator is a 2-dimensional system that incorporates with a tubular absorber. A new design theory is developed on the basis of the generalized edge-ray principle. The result shows the increase of concentration ratio for the same acceptance angle as the basic CPC by a factor of $C_{new}=C_{cpc}\{1+(d/{\pi}r)\;sin^2{\theta}_c\}$. For example, if ${\theta}_c=30^{\circ}$, the new design offers the concentration of $2.0{\sim}2.72$, whereas $C_{cpc}=2$. The new system also provide a thin and light-weight design.

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Spectral Element Modeling of the Rotating Shafts on Bearing Supports (베어링으로 지지된 회전축의 스펙트럴요소 모델링)

  • Lee, Jae-Sng;Lee, U-Sik
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.826-830
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    • 2008
  • In this paper, the vibration of a rotating shaft with a thin rigid disk on bearing supports is considered. It is assumed that the shaft has uniform, circular cross-section. Based on the Timoshenko-beam theory, the transverse displacements and slops in two lateral directions, the axial displacement, and the torsional deformation are considered. And flexible supports are used to analyse the bearings. A spectral element model is developed for the vibration analysis of the rotating shaft with a thin rigid disk, which is modeled by two shaft elements and a thin rigid disk element. The result of vibration analysis by finite element method is compared to the result of this research.

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Contribution of van der Waals Interactions to the Adsorption Energy of $C_2H_2$, $C_2H_4$, and $C_6H_6$ on Si(100)

  • Kim, Seon-U;Lee, Jun-Ho;Jo, Jun-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.269-269
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    • 2013
  • Usingvan der Waals (vdW) energy-corrected density-functional theory without or with self-consistent screening (SCS) effects, we calculate the adsorption energy of acetylene, ethylene and benzene on Si(100). We find that vdW interactions without SCS effects increase the adsorption energy by 0.23, 0.30, and 0.64 eV for adsorbed $C_2H_2$, $C_2H_4$, and $C_6H_6$ on Si(100), respectively. However, if SCS effects are included, this increase of the adsorption energy is reduced as 0.19, 0.24, and 0.54 eV for the three adsorption systems, respectively. The resulting adsorption energy for each system is between the values computed using the local-density approximation and the generalized-gradient approximation.

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