• Journal of Chest Surgery
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• 제32권12호
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• pp.1123-1126
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• 1999

Coronary artery bypass grafting (CABG) technique has been much developed but CABG under cardiopulmonary bypass has the unavoidable deficits such as generalized inflammatory reaction from cardiopulmonary bypass and myocardial ischemia from aortic-cross clamp. There has been remarkable advancement of CABG without cadiopulmonary bypass. We performed CABG successfully without cardiopulmonary bypass. We performed CABG successfully without cardiopulmonary bypass in two patients with multivessel coronary disease who were failed to intervene with percutaneous transluminal coronary angioplasty. We herein report the two cases.

• Journal of Chest Surgery
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• 제48권3호
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• pp.206-209
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• 2015

Ascending aortic aneurysms are usually treated with graft replacement under cardiopulmonary bypass. However, if a candidate for off-pump coronary artery bypass grafting has an enlarged ascending aorta, surgeons may consider wrapping it without cardiopulmonary bypass. Here, we report a 78-year-old female who underwent successful wrapping of the ascending aorta concomitant with off-pump coronary artery bypass grafting, using a new wrapping technique that involves multiple bootstraps.

• 한국전자파학회논문지
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• 제30권1호
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• pp.1-7
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• 2019

본 논문에서는 bypass capacitor를 이용하여 Band Stop Matching Circuit(BSMC)을 적용한 Inverted-F Antenna(IFA)의 효율을 향상 기법을 제안한다. 본 논문에서 설계한 안테나의 동작주파수는 LTE band 26과 5(814~894 MHz) 대역이다. BSMC의 임피던스 변화를 이용하여 IFA의 대역폭을 -6 dB 기준 823~886 MHz에서 800~888 MHz로 확장하였다. 확장된 주파수 대역에서 안테나의 효율을 향상시키기 위해 BSMC가 적용된 IFA에 bypass capacitor를 적용하였다. Bypass capacitor는 BSMC가 적용된 IFA의 전류 변화량를 감소시켜 안테나의 효율을 향상시켜주는 역할을 한다. Bypass capacitor를 적용시켰을 때 대역폭은 804~895 MHz이며 확장된 주파수 대역에서 안테나 효율은 10 % 이상 증가하였다.

• 전력전자학회논문지
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• 제17권5호
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• pp.416-422
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• 2012

This paper proposes a low power-loss current measurement using a resistor and bypass switch. Conventional current sensing method using a resistor has a disadvantage of power loss which degrades the efficiency of the entire systems. On the other hand, proposed measurement technique operating with bypass-switch connected in parallel with sensing resistor can reduce power loss significantly the current sensor. The propose measurement works for discrete-time sampling of current sensing. Even while the analog-digital conversion does not occur at the controller, the sensing voltage across the sensor still causes ohmic conduction loss without information delivery. Hence, the bypass switch bypasses the sensing current with a small amount of power loss. In this paper, a 90[W] prototype hardware has been implemented for photovoltaic MPPT experimental verification of the proposed low power-loss current measurement technique. From the results, it can be seen that PV power observation is successfully done with the proposed method.

• Journal of Chest Surgery
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• 제26권11호
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• pp.881-885
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• 1993

In the last few years there has been a resurgenceof interest in in-situ saphenous vein arterial bypass for lower extremity revascularization because of improved patency rates. we performed 1 in situ bypass oreration using the intraluminal valve-disruption tecnique. A 65-year-old female who had ztherosclerotic obstruction in the superficial and popliteal arteries underwent in situ saphenous vein arterial bypass. After harvesting of saphenous vein, we used LeMaitre retrograde valvulotome for valve-disruption technique. Completion of the arterrigraphy was performed to evaluate bothh the anastomoses. The two side brances were all ligated. In situ saphenous vein arterial bypass has become the procedure of choice for distal reconstruction in severely ischemic lower extremities because of improved long-term patency compared with reversed-saphenous vein bypass procedure.

• ETRI Journal
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• 제32권2호
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• pp.327-329
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• 2010

A fully integrated small form-factor HBT power amplifier (PA) was developed for UMTS Tx applications. For practical use, the PA was implemented with a well configured bottom dimension, and a CMOS control IC was added to enable/disable the HBT PA. By using helix-on-pad integrated passive device output matching, a chip-stacking technique in the assembly of the CMOS IC, and embedding of the bulky inductive lines in a multilayer substrate, the module size was greatly reduced to 2 mm ${\times}$ 2.2 mm. A stage-bypass technique was used to enhance the efficiency of the PA. The PA showed a low idle current of about 20 mA and a PAE of about15% at an output power of 16 dBm, while showing good linearity over the entire operating power range.

• Journal of Chest Surgery
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• 제29권11호
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• pp.1267-1269
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• 1996

관상동맥우회술은 인공심폐기 및 심근보호의 안정성으로 인공심폐기사용하에 시행하는 것이 보편화된방법이다. 그러나, 좌전행지 및 우관상동맥에 병소가 위치하는 경우는 인공심폐기의 사용없이 심장이 박동하는 상태에서 관상동맥우회술을 시행하는 방법도 일부에서 시행되어왔다 저자들은 좌전행지 및 대각지에 협착을보인 환자에서 인공심폐기를 사용하지 않고 성공적으로 관상동맥우회술을 시행하였기에 보고하는 바이다.

• 전자공학회논문지S
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• 제34S권8호
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• pp.45-55
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• 1997

To design a ATM Switch which ahs advantages in high sped packet switching, it is essential to set multiple paths between input ports and output ports and to design a new packet transfer technique on that paths for decreasing Packet Loss by conflicts in internal Switch Plane. We propose new packet transfer method, Alternate Path Transfer Mechanism by Dynamic Bypass Transfer Method which can solve conflict problem in Banyan network easily. Proposed ATM Switch consists of Banyan networks, Input/Ouput Port, Bypass Link, and Bypass Link Controller. Packets caused conflicts in SEs have another chances of packet transfer over alternate switching planes by using this mechanism.

• Journal of Korean Neurosurgical Society
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• 제65권4호
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• pp.603-608
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• 2022

Vertebral artery (VA) occlusion is frequently encountered, usually without acute ischemic injury of the brain. However, when it is accompanied by hypoplasia or stenosis of the opposite VA, brain ischemia may develop due to insufficient collateral supply. Both hemodynamic instability and embolic infarction can occur in VA occlusion, which may cause severe symptoms in a patient. Extracranial carotid-VA bypass should be considered for symptomatic VA occlusion patients, especially when the patient has repeated ischemic brain injuries. In this report, the cases of three extracranial carotid-VA bypass patients are introduced, along with a brief description of the surgical techniques. All three cases were treated with different bypass methods according to their disease location.

• 전력전자학회논문지
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• 제19권2호
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• pp.133-138
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• 2014

This paper proposes a low power-loss averaging current mode control using a resistor and bypass switch. Generally, current sensing method using a resistor has a disadvantage of power loss which degrades the efficiency of the entire systems. On the other hand, proposed measurement technique operating with bypass-switch connected in parallel with sensing resistor can reduce power loss significantly the current sensor. An analog-circuited bypass driver is implemented and used along with an average-circuit mode controller. The bypass switch bypasses the sensing current with a small amount of power loss. In this paper, a 50[W] prototype average current mode boost converter has been implemented for the experimental verification.