• 제목/요약/키워드: Transfer efficiency

검색결과 2,708건 처리시간 0.031초

DEA 모형을 이용한 공공연구기관의 기술이전 효율성 분석에 관한 연구 (A Study on the Technology Transfer Efficiency for Public Institutes Using DEA Model)

  • 현만석;유왕진
    • 산업경영시스템학회지
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    • 제31권2호
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    • pp.94-103
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    • 2008
  • This study measured technology transfer efficiency for public institutes. The study made use of DEA being one of the non-parametric linear programming to evaluate technology transfer efficiency for public institutes and to measure technology efficiency, pure technical efficiency and scale efficiency. The measurement of the technology transfer efficiency for public institutes was as follows: The cause of the technology transfer inefficiency was affected by pure technical inefficiency more than by scale inefficiency. Public institutes' RTS(Return To Scale) value varied depending upon the features of the organizations than the features of the regions. Public research institutes' RTS value is more effective than universities' RTS value. We compared the RTS group with the RTS of Projected DMU groups. The RTS group had constant returns to scale effect while the RTS of the Projected DMU had increasing returns to scale effect. The technology transfer efficiency of public institutes varied depending upon the features of the organizations and regions : The technology transfer efficiency of public institutes were as follows : public research institutes at the metropolitan area, public research institutes at the local areas, universities at the metropolitan area and universities at the local areas. In other words, the technology transfer efficiency was affected by organizational characteristics more than by regional characteristics at the place where public institutes were located.

콘크리트포장에서 하중전달효과 영향인자 연구 (A Study on Effect Factor of Load Transfer Efficiency in Concrete Pavement)

  • 양홍석;서영찬;권수안
    • 한국도로학회논문집
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    • 제3권3호
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    • pp.147-158
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    • 2001
  • 콘크리트포장의 구조적 능력을 평가하는 가장 중요한 요소 중의 하나는 하중전달효과이다. 하중전달효과는 슬래브 상 하부 온도차, 다우월바 시공여부, 포장 노후도, 그리고 균열틈 등에 영향을 받는다. 본 연구의 목적은 콘크리트 포장의 하중전달효과 특성을 파악하고 하중전달효과에 영향을 주는 요소를 정량화하고 적절한 하중전달효과 조사방법을 제시하는 것이다. 연구결과 하중전달효과는 슬래브 표면온도가 아닌 슬래브 평균온도 영향을 받는 것으로 나타났다. 하중전달효과는 온도가 내려가고 균열틈이 벌어질수록 감소하는 것으로 나타났다. 다우월바를 시공한 구간의 경우 온도변화에 따라 하중전달효과는 큰 차이를 보이지 않은 반면, 다우월바를 시공하지 않은 구간에서는 온도가 내려갈수록 하중전달효과는 급격히 감소하였다. 다우월바를 시공한 구간이라도 포장이 노후화되면 하중전달효과는 온도가 하락함에 따라 감소하는 것으로 나타났다. 본 조사대상 구간에서는 슬래브 단위온도 하락시 하중전달효과는 1.4% 감소하는 것으로 나타났다.

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Enhancement of Wireless Power Transfer Efficiency Using Higher Order Spherical Modes

  • Kim, Yoon Goo;Park, Jongmin;Nam, Sangwook
    • Journal of electromagnetic engineering and science
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    • 제13권1호
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    • pp.38-43
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    • 2013
  • We derive the Z-parameters for the two coupled antennas used for wireless power transfer under the assumption that the antennas are canonical minimum scattering antennas. Using the Z-parameter and the maximum power transfer efficiency formula, we determine the maximum power transfer efficiency of wireless power transfer systems. The results showed that the maximum power transfer efficiency increases as the mode number or the radiation efficiency increases. To verify the theory, we fabricate and measure two different power transfer systems: one comprises two antennas generating $TM_{01}$ mode; the other comprises two antennas generating $TM_{02}$ mode. When the distance between the centers of the antennas was 30 cm, the maximum power transfer efficiency of the antennas generating the $TM_{02}$ mode increased by 62 % compared to that of the antennas generating the $TM_{01}$ mode.

자기공진방식의 무선전력전송 시스템에서 공진 중계기 적용 여부에 따른 전력전송 효율 분석 (Analysis of the Efficiency According to Resonant Repeater Application in Magnetic Resonant Wireless Power Transfer System)

  • 백승명;김동은;손진근
    • 전기학회논문지P
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    • 제67권4호
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    • pp.221-226
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    • 2018
  • In this paper, the power transfer efficiency analysis based on the resonant repeater in a magnetic resonance wireless power transfer system is proposed. The efficiency of the magnetic resonance method was verified by comparing the general frequency with the resonance frequency. The resonance repeater was arranged to increase the efficiency and increase the transfer distance. When using resonant repeaters, the maximum efficiency increase is about 36.23[%] and the transfer distance was extended to more than 20[cm]. Through this study, confirmed the effect of using resonance repeaters in wireless power transfer system. As a result, it can be expected that the overall technology related to wireless power transfer system will be more valuable for energy-IT technology.

열과 물질 전달을 수반하는 연속휜의 휜효율에 관한 연구 (A Study on the Fin Efficiency of Continuous Fin with Combined Heat and Mass Transfer)

  • 정세환
    • Journal of Advanced Marine Engineering and Technology
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    • 제22권4호
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    • pp.445-450
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    • 1998
  • In the present paper the effects of combined heat and mass transfer on the fin efficiency were calculated. Sector method was used for calculating the fin efficiency of the continuous fin. The parameter Lewis No. and C which describe the combined heat and mass transfer is derived by using the heat and mass transfer analogy and effects of Lewis No. and C on the fin efficiencies were calculated.

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Effects of Technology Transfer Policies on the Technical Efficiency of Korean University TTOs

  • HAN, JAEPIL
    • KDI Journal of Economic Policy
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    • 제40권4호
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    • pp.23-45
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    • 2018
  • The Korean government has provided various policy devices to boost technology transfers between academia and industry since the establishment of the Technology Transfer Promotion Act in 2000. Along with the enactment of the law, the Korean government mandated the establishment of a technology transfer office at national and public universities and encouraged technology transfer activities. Despite the quantitative expansion of technology transfer offices (TTOs), operational inefficiency was brought up. As a supplementary policy, the Korean government implemented a line of projects to support the labor and business expenses of leading TTOs. This research questions whether the project greatly affected the technical efficiency of TTOs. We analyze publicly available university panel data from 2007 to 2015 using a one-step stochastic frontier analysis. The results suggest that the program was marginally effective at shifting the technical efficiency distribution to the right on average, but it failed to maximize its impact by diversifying the policy means based on targets. The marginal effects of the program on technical efficiency differ according to the research capability and size of each school. We also compare technical efficiency against the licensing income at the start and end of the program. Technical efficiency increased for the leading TTOs, and both measures show improvements for unsupported TTOs. Our empirical results imply that diversifying the program for universities with different characteristics may have improved the effectiveness of the policy.

판형 휜을 갖는 열교환기의 휜효율에 관한 수치해석적 연구 (Numerical study for the fin efficiency of the heat exchanger having plate fins)

  • 강희찬
    • 설비공학논문집
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    • 제11권6호
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    • pp.903-911
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    • 1999
  • This study is discussed about the heat transfer coefficient and the fin efficiency of the heat exchanger having plate fins. A new definition for the fin efficiency of the heat exchanger is proposed. More than one hundred cases were tested numerically for the plate fins having uniform and non-uniform heat transfer coefficient. The previous models for the fin efficiency and the pure heat transfer coefficient were applicable to the heat exchanger only when the NTU is very small. It was found that the fin efficiency of the heat exchanger was nearly the same as the normalized fin temperature. The present model could estimate the pure heat transfer coefficient within a few percent in the present test range of 0<NTU<2.5.

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Experimental technique for efficiency transfer along different geometries and volumes

  • Haddad, Kh;AL-Homyed, A.
    • Nuclear Engineering and Technology
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    • 제53권2호
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    • pp.695-698
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    • 2021
  • Efficiency calibration is a fundamental procedure in gamma spectrometric measurement. Experimental technique for efficiency calibration transfer in gamma spectrometer along different geometries and volumes has been developed and validated in this work. The developed technique offers simple and easy procedures to overcome several problems encountered in efficiency calibration of gamma spectrometer such as rate-related correction and different sample volumes. The validation shows that application of the developed technique has a precision of 95%.

피로실험에 의한 콘크리트 포장체 경사가로줄눈부의 하중전달율에 관한 연구 (A Study on Load Transfer Efficiency of Skewed Transverse Joint of Concrete Pavement by the Fatigue Test)

  • 황승의;배주성
    • 한국구조물진단유지관리공학회 논문집
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    • 제5권3호
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    • pp.203-211
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    • 2001
  • This paper presents load transfer efficiency of skewed transverse joint of jointed concrete pavement with the fatigue model test. A 1/12 scale model was used to satisfy the geometry, loading, material similitude, which are variables to the skew angel of transverse joint. As the test results by fatigue load 700kgf applied, the deflection and stress of transverse joint were decreased as to increasing of skew angle of transverse joint. In addition, load transfer efficiency of transverse joint with skew angle is better than the load transfer efficiency of transverse joint without skew angle.

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Performance Analysis of Contactless Electrical Power Transfer for Maglev

  • Hasanzadeh, S.;Vaez-Zadeh, S.
    • Journal of Magnetics
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    • 제17권2호
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    • pp.115-123
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    • 2012
  • Contactless electrical power transfer through an air gap is a revived technology for supplying energy to many movable applications including Maglev. In this paper, magnetic equivalent circuits and analytical models of contactless electrical power transfer systems are developed and evaluated through experiment. Overall coupling coefficient and overall efficiency are introduced as means for evaluating the systems' performance. Compensating capacitors in primary and secondary sides of the systems improve the overall coupling coefficient and overall efficiency. Using the analytical models, the effects of different parameters and variables such as air gap and load current are analyzed to give a high coupling coefficient and an improved efficiency of power transfer for different compensation structures.