• 제목/요약/키워드: Transfer unit

검색결과 853건 처리시간 0.028초

공공기술 이전, 기술적 성과, 연구개발 생산성 간의 구조적 관계 분석 (The Analysis of Structural Relationships among Public Technology Transfer, Technological Performance, and R&D Productivity)

  • 전지은;권상집
    • 지식경영연구
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    • 제19권2호
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    • pp.1-19
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    • 2018
  • This study aims to identify the causal relationship among public technology transfer, technological performance, and research and development (R&D) productivity. Using the impulse-response function(IRF) of a panel vector autoregressive model (panel VAR), this study suggests the results of how long the factors such as technological performance (patent), public technology transfer, and R&D productivity takes and lasts if a one-unit shock of standard deviation occurs. As a result, first, the increase of public technology transfer activities has no power to increase the technology performance but improve the R&D productivity. If the public institute increases its technology transfer activities by one unit, the R&D productivity will increase within five years. Second, the impact of increasing technological performance on improvement of public technology transfer and R&D productivity is an insignificant. Third, the effect of R&D productivity on the public technology transfer creates a substantial reaction after a current time. Considering the structural relationships among public technology transfer, technological performance, and R&D productivity, if policy makers intend to construct the active R&D circumstance, technology suppliers should be motivated to run the active R&D mechanism because they achieve gains.

수중 모터펌프 베어링 유닛 열전달 해석 (Heat Transfer Analysis of Bearing Unit in Submersible Motor Pump)

  • 윤정의;변형균
    • Tribology and Lubricants
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    • 제27권4호
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    • pp.198-203
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    • 2011
  • The purpose of this paper is to find a proper cooling system of bearing unit in the submersible motor pump to extend a life time. To do this, heat transfer analysis of the submersible motor pump were performed using commercial CFD code ANSYS. In order to obtain the resonable heat transfer simulation results, we first set up mathematical model of heat source in the bearing system, and carried out heat transfer analysis with the model. As a results, new type bearing cap which had several ribs for cooling the bearing was proposed. Finally, through the comparison between experimental results of old and new model pump, we proofed that maximum bearing temperature of new model was about 10% lower than that of old model.

Reliability analysis of repairable k-out-n system from time response under several times stochastic shocks

  • Fang, Yongfeng;Tao, Wenliang;Tee, Kong Fah
    • Smart Structures and Systems
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    • 제14권4호
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    • pp.559-567
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    • 2014
  • The model of unit dynamic reliability of repairable k/n (G) system with unit strength degradation under repeated random shocks has been developed according to the stress-strength interference theory. The unit failure number is obtained based on the unit failure probability which can be computed from the unit dynamic reliability. Then, the transfer probability function of the repairable k/n (G) system is given by its Markov property. Once the transfer probability function has been obtained, the probability density matrix and the steady-state probabilities of the system can be retrieved. Finally, the dynamic reliability of the repairable k/n (G) system is obtained by solving the differential equations. It is illustrated that the proposed method is practicable, feasible and gives reasonable prediction which conforms to the engineering practice.

전열제어를 위한 충돌제트의 거리비에 따른 열전달특성에 관한 연구 (A Study on Heat Transfer Characteristics of Impinging Jet about Distance Ratio leer Thermal Control)

  • 김동균;김정환;배석태;김시범;이영호
    • Journal of Advanced Marine Engineering and Technology
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    • 제25권6호
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    • pp.1237-1243
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    • 2001
  • This paper presents an information about the heat transfer characteristics of impinging jet in eletronic equipment with infrared image processing unit. There have been many experimental investigations and theoretical studies on impinging jet because of application in a wide variety of industrial process including electronic equipment. In this study, we used infrared image processing unit to visualize heat transfer characteristics of impinging jet in eletronic equipment. Infrared image processing unit is one of non-contact temperature measuring methods and it is possible to minimize flow resistance and this measurement is comparatively accurate. The main parameters are distance between nozz1e and heat source. Reynolds number is 6000.

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적외선열화상처리장치를 이용한 충돌제트의 전열특성에 관한 연구 (A Study on Heat Transfer Characteristics of Impinging Jet Using Infared Thermal Image Processing System)

  • 김동균;배석태;김시범;이영호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.711-716
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    • 2001
  • This paper presents an information about the heat transfer characteristics of impinging jet in eletronic equipment with infrared image processing unit. There have been many experimental investigations and theoretical studies on impinging jet because of application in a wide variety of industrial process including electronic equipment. In this study, we used infrared image processing unit to visualize heat transfer characteristics of impinging jet in electronic equipment. Infrared image processing unit is one of non-contact temperature measuring methods and it is possible to minimize flow resistance and this measurement is comparatively accurate. The main parameters are nozzle exit angle $(30^{\circ},\;45^{\circ},\;60^{\circ},\;75^{\circ},\;90^{\circ})$ and distance between nozzle and heat source is fixed 6d("d" is diameter of circular nozzle(10 mm). Reynolds number is 4500.

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전방향 이동 머니퓰레이터 시스템의 여유자유도 최적화 방법 (Redundancy resolution method of omni-directional mobile manipulator system)

  • 권순재;정재웅
    • 동력기계공학회지
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    • 제19권3호
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    • pp.75-80
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    • 2015
  • Typically, robot system configured by articulated robot manipulator with 1 DOF transfer unit is being applied in automotive manufacturing automation process. Especially, 1 DOF transfer unit is necessary to extend workspace of robot manipulator. In this configuration, because transfer unit works only one direction, robot manipulator only works in one side in case of car body painting or sealing automation process. it is necessary three robot manipulator system at least. In this paper, in order to robot manipulator works effectively in car body sealing automation application, we are suggested omni-directional manipulator system and conducted studying on redundancy resolution method to solve manipulability-optimal problem.

지역별 예비력 제약과 융통전력을 고려한 발전기 예방정비 계획 해법 (Generating Unit Maintenance Scheduling Considering Regional Reserve Constraints and Transfer Capability Using Hybrid PSO Algorithm)

  • 박영수;박준호;김진호
    • 전기학회논문지
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    • 제56권11호
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    • pp.1892-1902
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    • 2007
  • This paper presents a new generating unit maintenance scheduling algorithm considering regional reserve margin and transfer capability. Existing researches focused on reliability of the overall power systems have some problems that adequate reliability criteria cannot be guaranteed in supply shortage regions. Therefore specific constraints which can treat regional reserve ratio have to be added to conventional approaches. The objective function considered in this paper is the variance (second-order momentum) of operating reserve margin to levelize reliability during a planning horizon. This paper focuses on significances of considering regional reliability criteria and an advanced hybrid optimization method based on PSO algorithm. The proposed method has been applied to IEEE reliability test system(1996) with 32-generators and a real-world large scale power system with 291 generators. The results are compared with those of the classical central maintenance scheduling approaches and conventional PSO algorithm to verify the effectiveness of the algorithm proposed in this paper.

클린 튜브 시스템 이송 유닛의 웨이퍼 운동 역학 모델링 (Wafer Motion Modeling of Transfer Unit in Clean Tube System)

  • 신동헌;정규식;윤정용
    • 한국정밀공학회지
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    • 제21권3호
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    • pp.66-73
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    • 2004
  • This paper presents wafer motion modeling of transfer unit in clean tube system, which was developed as a means for transferring the air-floated wafers inside the closed tube filled with the super clean airs. When the wafer is transferred in x direction with an initial velocity the motion along x direction can be modeled as a simple decaying motion due to viscous friction of the fluid. But, the motion in y direction is modeled as a mass-spring-damper system where the recovering force by air jets issued from the perforated is modeled as a linear spring. Experiments with a clean tube system built fur 12 wafer show the validity of the presented force and motion models.

메타구조 기반의 고효율 공진형 무선전력전송 시스템 (Resonant Wireless Power Transfer System with High Efficiency using Metamaterial Cover)

  • 김형준;서철헌
    • 전자공학회논문지
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    • 제51권1호
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    • pp.47-51
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    • 2014
  • 본 논문에서는 공진형 무선전력전송 시스템의 효율 개선을 위해 메타구조 기반의 단위 셀 및 배열 된 구조를 제안하였다. 자기장 집속을 위해 제로 굴절률 특성을 이용하였으며, 이를 구현하기 위해 유효 투자율의 실수가 0의 값을 갖도록 설계하였다. 제안된 단위 셀의 크기는 $70mm{\times}70mm{\times}3.2mm$이며, 동작 주파수는 13.56 MHz 이다. 또한, 배열된 구조의 크기는 $400mm{\times}400mm{\times}3.2mm$이며, 2-layer 구조로 이루어져 있다. 본 논문에서 제안한 공진형 무선전력전송 시스템의 효율은 송수신 공진기 사이의 거리가 100 mm ~ 400 mm에서 각각 94.8 %, 93.2 %, 91.4 %, 90.8 % 이며, 전체 거리에서 90 % 이상의 고효율 특성을 얻을 수 있었다.