• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.69-71
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• 2001

본 논문에서는 FACS(fluorescence activated cell sorting)의 초소형화를 위한 미세 유체소자들을 플라스틱 기판에 집적하여 제작하고 전기삼투를 이용해서 세포가 일렬로 이송되는 특성을 시험한다. 제작된 미세 유체 소자는 유리 하부 기판과 플라스틱 상부 기판 및 전원장치로 구성된다. 상부기판은 세포를 주입하기 위한 샘플 측 레저버와 세포를 운반 및 일렬 이송이 가능하게 하는 버퍼를 저장할 두 개의 레저버가 있고 이들이 배출되는 레저버로 구성된다. 마이크로머시닝 기술을 이용하여 실리콘 기판 위에 미세 채널 몰드를 제작한 후 PDMS(polydimethylsiloxane)로 주물을 제작한다. $O_2$ 플라즈마를 이용하여 유리 기판과 PDMS 주물을 접합하며 제작된 채널에 적색 잉크와 bead를 샘플 측에 충전하고 버퍼 측에 sodium borate를 충전한 후 전기삼투로 구동시킨다. bead가 일렬로 이송되도록 전장을 조절하고 이때의 유속과 유량을 측정한다. 다양한 전장에 따른 실험을 통하여 채널의 구조를 최적화한다.

• The KSFM Journal of Fluid Machinery
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• v.8 no.1 s.28
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• pp.16-22
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• 2005

This paper presents the method of ROL(Rate Of Loading) improvement for the Motor Operated Gate Valve operated in high differential pressure condition. ROL is one of the most important evaluation parameters for the valve ability. It is close to correlation in stem factor (SF) and appears different value by the differential pressure of fluid. ROL and SF are analyzed by the static test and dynamic test. The obtained result show that the modification of stem factor is very important factor for the ROL improvement. In order to obtain the same value of SF between static and dynamic test, stem and stem nut should be combined appropriately by the repetition test.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.481-487
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• 2004

Air-operated valve is one of principal valves that are using to control fluid flow in nuclear power plants. A period diagnosis lot safety of power plants is necessary. But there are many difficulties such as economic loss caused by income of high cost devices and a matter hard to deal with users. In this study, we developed the diagnostic system that users of power plants are easy to handle. The diagnostic system is composed of database module, diagnosis test module and evaluation module.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.166-171
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• 2004

The Rate-of-Loading(ROL) effect of motor operated gate valves causes a decrease in the thrust delivered at a specific torque by the actuator under dynamic flow ${\Delta}$P conditions as compared to the no-flow, static conditions. This effect needs to be studied for the quantitative evaluation of motor operated gate valve operability. This study is performed to verify the validity for the application of ROL in the evaluation of operability of motor operated gate valves for the opening stroke. The ROL is assessed on the basis of in-situ test data for the opening and closing strokes. The results show that the distribution of the ROL for the operling sake has a tendency to the negative value when DP is higher than 150psid.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.10
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• pp.993-1001
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• 2001

Experimental investigation on the performance of dual-evaporator refrigeration system with an ejector has been carried out. In this study, a hydrofluorocarbon (HFC) refrigerant R134a is chosen as a working fluid. The condenser and two-evaporators are made as concentric double pipes with counter-flow type heat exchangers. Experiments were performed by changing the inlet and outlet temperatures of secondary fluids entering condenser, high-pressure evaporator and low-pressure evaporator at test conditions keeping a constant compressor speed. When the external conditions (inlet temperatures of secondary fluid entering condenser and one evaporator) are fixed, results show that coefficient of performance (COP) increases as the inlet temperature of the other evaporator rises. It is also shown that the COP decreases as the mass flaw rate ratio of suction fluid to motive fluid increases. The COP of dual-evaporator refrigeration system with an ejector is superior to that of a single-evaporator vapor compression system by 3 to 6%.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.69-70
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• 2015

이덕터는 구동부를 통해 공급되는 작동유체가 노즐을 통과하면서 고속으로 분출됨으로써 벤츄리 효과에 의해 노즐 출구 주위에 부압이 형성됨에 따라 흡입부를 통해 유체가 흡입된다. 이덕터의 주요 설계인자는 노즐의 직경과 스로트의 직경 및 직관부 길이 그리고 노즐과 직관부 시작점까지의 거리이다. 이 연구에서는 선박용 인라인 이덕터에 대한 기초연구로서 흡입 메카니즘을 체계적으로 해석할 목적으로 주요 설계인자를 이론적으로 고찰하고 설계인자의 변화에 따른 성능실험 가능하도록 이중원관의 형태로 모델링하였다.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.562-567
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• 2003

This paper presents the method of Rate of Loading(ROL) improvement for the Motor Operated Gate Valve operating in high differential pressure condition. The character of ROL and Stem Factor is analyzed. Static test and dynamic test were performed and acquired the diagnosis signal for the valve closing stroke. The result of this study is the modification of stem factor is very important factor for the ROL improvement. In order to obtain the same value of dynamic test thread friction coefficient stem and stem nut should be combined appropriately.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.139-144
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• 2002

본 연구에서 열발생탱크, 모타, 로타와 스탯, 순환펌프, 열교환기로 구성된 풍력-열변환시스템을 제작하여 열교환에 미치는 몇 가지 요인에 대하여 시험하였다. 주요결과는 다음과 같다. 가. 풍력열교환시스템은 발열부, 구동부, 열교환부로 구성하였다. 나. 열교환성능시험에서 열교환에 미치는 요인은 유체주입량 3수준, 점성유체의 종류 2수준, 로타의 졸류 3수준, 로타와 스텟의 간격 3수준으로 정하여 열교환시험을 하였다. 다. SAS GLM procedure를 사용하여 열교환량에 대한 각 처리의 효과에 대해 조사해본바 유체주입량이 열 교환량에 가장 큰 영향을 미친다는 것을 발견했다. 라. 최고열교환량은 처리조건 R3 로타, 유체주입량 110 L, 로타와 스텟의 간격 17mm, A 오일에서 발생했으며 7,800 kcal/h 가 되었다. 마. 열 변환효율을 극대화하려면 열발생탱크의 직경보다는 높이를 크게 하고 유체를 최대 높이까지 주입하는 것이 바람직하리라 사료된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.25-30
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• 2013

The piezoelectric-based hydraulic actuator is a hybrid device consisting of a hydraulic pump driven by piezoelectric stacks that is coupled to a conventional hydraulic cylinder via a set of fast-acting valves. Nowadays, such hybrid actuators are being researched and developed actively in many developed countries by requirement of high performance and compact flight system. In this research, operation principle and performance testing of the hybrid actuator were introduced. Output velocities have been measured in both loaded case and not loaded case and the blocking force also has been measured in external loaded case. The maximum velocity of the actuator is 53.3 mm/s, blocking force is 240.7 N and corresponding power output is 3.2 W.

• Journal of Drive and Control
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• v.4 no.2
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• pp.27-34
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• 2007