• Title/Summary/Keyword: 바이패스

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Right Heart Support in OPCAB -2 cases Report- (우심실 보조장치 하의 심장박동 상태에서 시행한 관상동맥 우회수술 -2례 보고-)

  • 조석기;김기봉
    • Journal of Chest Surgery
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    • v.33 no.11
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    • pp.906-909
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    • 2000
  • 심폐바이패스를 사용하지 않고 심장박동 상태에서 시행하는 관상동맥 우회수술은 심 비대와 좌심실 기능저하가 동반된 협증심 환자에서는 심장 뒤쪽에 위치한 관상동맥에 대한 접근이 어렵고 수술 중 혈역학적으로 불안정하여 시행하기에 어려운 경우가 많다. 우심실 보조장치 하의 심장박동 상태에서 시행하는 관상동맥 우회수술은 대동맥의 삽관을 피하고, 심폐바이패스의 합병증을 줄일 수 있으며, 심장 뒤쪽에 위치한 혈관의 문합시에도 안정된 혈역학적 상태를 유지 할 수 있어 고위험군 환자에게 도움을 줄 수 있다. 좌심실 기능저하와 심 비대가 동반된 환자에서 우심실 보조장치 하의 심장박동 상태에서 시행한 관상동맥 우회수술을 2례 시행하여 좋은 결과를 얻어 보고하고자 한다.

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The Characteristics of a Bypass Air Conditioning System for Load Variation (부하변동에 대한 바이패스 공조시스템의 특성)

  • 김보철;신현준;김정엽
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.3
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    • pp.240-246
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    • 2002
  • Bypass air conditioning systems are divided into three types; an outdoor air bypass, a mixed air bypass and a return air bypass system. What makes the return air by pass system more effective is that it directs all of moist outdoor air through the cooling coil. The bypass air conditioning system can maintain indoor R.H (Relative Humidity) less than a conventional CAV (Constant Air Volume) air conditioning system by adjusting face and bypass dampers at part load. When a design sensible load (the ratio of sensible load to total sensible load) is 70 percent (at this time, RSHF (Room Sensible Heat Factor) . 0.7), indoor R.H was maintained 59 percent by the return air bypass system, but 65 percent by the conventional CAV air conditioning system (valve control system). The bypass air conditioning system can also improve IAQ (Indoor Air Quality) in many buildings where the number of air change is high.

Supra-Arterial Myotomy without Cardiopulmonary Bypass for Myocardial Bridging -One case report- (심폐바이패스없이 관상동맥 심근교의 수술치험 -1례 보고-)

  • 김재현;최세영;유영선;이광숙;윤경찬;박창권
    • Journal of Chest Surgery
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    • v.32 no.2
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    • pp.181-184
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    • 1999
  • Systolic coronary arterial narrowing, secondary to myocardial bridging which is capable of producing chest pain, myocardial infarction and ventricular fibrillation is a known but an uncommon entity. A supra-arterial myotomy in a case of myocardial bridge causing medication-refractory angina is described. Under the partial sternotomy incision, we performed a supra-arterial myotomy in the left anterior descending coronary artery without cardiopulmonary bypass. The postoperative course was uneventful.

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Study of monitoring technique using Raman amplification for long distance optical (라만증폭기를 이용한 장거리 광 전송망 감시 연구)

  • Kim Byung-Jun;Choi Hyun-Beom;Seo Dea-Dong;Lee Dong-Han;Jeon Jeoung-U;Lee Yung-Tark
    • 한국정보통신설비학회:학술대회논문집
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    • 2003.08a
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    • pp.163-164
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    • 2003
  • 현재의 OTDR 기술은 150km 이상의 광선로를 감시하기 어렵다. 이 문제를 해결하기 위하여 라만 증폭기를 사용하여 장거리의 기간 전송망을 감시할 수 있는 바이패스 모듈을 구성하였다. 1625nm 파장에서 11dB 이득을 갖는 라만 증폭기가 포함된 바이패스 모듈을 사용하여 300km의 광전송라인을 감시할 수 있는 기술을 확보하였다.

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Experimental and Numerical Analyses of flow field in a bypass valve (바이패스밸브 유동장에 관한 실험 및 수치해석)

  • Choi, Ji-Yong;Cho, An-Tae;Kim, Kwang-Yong
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.527-530
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    • 2006
  • In the present work, characteristics of the flow in the cage of a steam turbine bypass control valve for thermal power plant are investigated. Experimental measurement for wall static pressure has been carried out to validate numerical solutions. And, the flowfield is analyzed by solving steady three-dimensional Reynolds-averaged Navier-Stokes equations. Shear stress transport (SST) model is used as turbulence closure. The effects of the flow area between stages of the cage on the pressure drop are also found.

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Nonlinear Robust Control of Passenger Car Torque Converter Bypass Clutch (승용차용 토크컨버터 바이패스 클러치의 비선형 견실제어)

  • Han, Jin-Oh;Kang, Soo-Joon;Lee, Kyo-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.8
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    • pp.1251-1258
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    • 2003
  • This paper presents a nonlinear robust approach to the slip control problem for a torque converter bypass clutch in a passenger car. The proposed nonlinear robust controller builds upon only the measurements avail-able from inexpensive sensors that are already installed in passenger cars for control. The issue of torque estimation problems for the implementation of the proposed controller is addressed. The stability of the internal dynamics is investigated, upon which a nonlinear robust controller is designed using input-output feedback linearization and Lyapunov redesign technique. The performance of the designed controller is validated by simulation studies.

Effect of Gas Bypass at Turbine Inlet on Design of a Pressurized Solid Oxide Fuel Cell / Gas Turbine Hybrid System (가압형 고체산화물 연료전지 / 가스터빈 하이브리드 시스템 설계에서 터빈입구 바이패스의 효과)

  • Park, S.K.;Sohn, J.L.;Kim, T.S.
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.1
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    • pp.33-39
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    • 2008
  • Hybrid power generation systems combining a solid oxide fuel cell and a gas turbine is promising due to their high efficiency. In the pressurized hybrid system, the operating condition of the gas turbine may play a critical role in designing the hybrid system. In particular, prevention of surge of the compressor can be a critical issue. The existence of fuel cell between the compressor and the turbine may cause an additional pressure loss and thus compressor operating points tend to approach the surge if the original turbine inlet temperature is pursued. In this study, bypassing some of the turbine inlet gas directly to the turbine exit side is simulated. Its effects on suppressing the surge problem and change in performance characteristics are discussed.

Performance Evaluation on an MR Damper Featuring Bypass Hole for Passenger Vehicle (바이패스홀을 특징으로 하는 승용차용 MR 댐퍼의 성능 평가)

  • Oh, Jong-Seok;Shin, Do-Kyun;Sohn, Jung-Woo;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.998-999
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    • 2014
  • This paper proposes a method for damping force modeling of magnetorheological (MR) damper featuring bypass hole. After describing configuration and of the MR damper, a damping force modeling of the MR damper is derived based on Bingham model of MR fluid. MR damper consists of piston, accumulator, gap, bypass hole and coil. Damping force is consists of spring force induced by accumulator, viscous force induced at gap and bypass hole, and controllable force induced at gap.

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