• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.399-402
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• 2003

In this paper, the on line volt/var control algorithms of the food Load Tap Changer (LTC) transformer and Shunt Capacitor(SC) are proposed for distribution volt/var regulation. In the existing volt/var control of the distribution substation, the voltage of feeders and var of distribution systems is mainly controlled by the LTC transformer tap position and on/off status of the shunt capacitor. The LTC and shunt capacitor bank has discrete operation characteristics and therefore it is very difficult to control volt/var at the distribution networks within the satisfactory levels. Also there is limitation of the operation times of the LTC and shunt capacitor bank because it is affects on their functional lifetime. The proposed volt/var control algorithm determine an optimal tap position of LTC and on/off status of shunt capacitors at a distribution network with the multiple feeders. The mathematical equations of the proposed method are introduced. Simple case study was performed to verify the effectiveness of the proposed method.

• 대한두개안면성형외과학회지
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• 제18권3호
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• pp.186-190
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• 2017

We report a case of free flap deterioration which may have been induced by pressure gradient resulting from cranial defect overlying a ventriculoperitoneal shunt (VP shunt). The patient, male and aged 78, had a VP shunt operation for progressive hydrocephalus. Afterwards, the scalp skin flap surrounding the VP shunt collapsed and showed signs of necrosis, exposing part of the shunt catheter. After covering the defect with a radial forearm free flap, the free flap site showed signs of gradual sinking while the vascularity of the flap remained unimpaired. An agreement was reached to remove the shunt device and observe the patient for any neurological symptoms, and after the shunt was removed and the previous cranial opening filled with fibrin glue by Neurosurgery, we debrided the deteriorated flap and provided coverage with 2 large opposing rotational flaps. During 2 months' outpatient follow-up no neurological symptoms appeared, and the new scalp flap displayed slight depression but remained intact. The patient has declined from any further follow-up since.

• Journal of Chest Surgery
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• 제38권4호
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• pp.277-283
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• 2005

다양한 선천성 심기형에서 전신-폐 단락술을 시행하는 경우 단락의 기술적 실패에 의한 폐색이 없이 수술 후 산소포화도가 불안정한 경우가 있다. 이에 전신-폐 단락술 후 산소포화도 불안정성의 빈도 및 위험 인자를 분석하고 그 원인 기전에 대해 고찰하였다. 대상 및 방법: 1996년 1월부터 2000년 12월까지 전신-폐 단락술을 받은 환자 중 폐동맥의 적절한 성장으로 단심실 혹은 양심실 교정을 받았거나 받을 예정인 93명의 환자를 연구 대상으로 하였다. 환자들의 연령, 수술 당시 체중, 수술 전혈색소치는 각각 3일-36세(중간 값: 1.8개월), 2.3-51kg (중간 값: 4.1kg), $10.7\~24.3$ gm/dL (중간 값: 15.2 gm/dL)이었다. 진단은 폐동맥 폐쇄나 협착을 동반한 기능적 단심실(39예), 활로씨 4징증(38예), 심실중격결손이 없는 폐동맥 폐쇄(16예)의 순이었고, 폐혈류 공급원은 동맥관이나 기존 단락(64예) 및 협착성 우심실 유출로를 통한 전방 혈류(29)였다. 수술 후 단락의 기술적 실패나 호흡 보조의 문제점이 없이 산소포화도가 1시간 이상 $50\%$ 미만으로 유지되었던 경우 산소 포화도 불안정성으로 정의하였다. 결과: 수술 후 10명$(10.7\%)$의 환자에서 산소포화도의 불안정성을 보였으며, 심초음파로 단락의 폐색 가능성을 배제한 뒤 폐혈관 저항을 감소시키는 치료를 통해 모두 수 시간 내에 산소포화도를 회복시킬 수 있었다. 산소포화도의 불안정성의 위험 인자로는 수술 시 연령의 증가(p=0.039),수술 전 낮은 산소 포화도(p=0.001) 및 응급 수술(p=0.0001) 등이었고, 협착성 우심실 유출로를 통한 전방 혈류에 의한 폐혈류 공급은 약간의 유의성을 나타내었다(p=0.065). 걸론: 단락이 필요한 선천성 심기형 환자가 수술 전 저산소증이 심하고 혈역학이 불안정한 경우 수술 후 폐혈관 저항의 일시적 상승에 의해 산소포화도의 불안정성이 나타날 수 있으며, 이 경우 폐혈관 저항을 감소시키는 치료를 통하여 산소포화도를 안정시킬 수 있다.

• Journal of Chest Surgery
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• 제15권2호
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• pp.194-203
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• 1982

In this investigation we undertook to evaluate the utility of radionuclide cardiac angiography in the detection of cardiac shunts before and after surgical correction. Time-activity curves of ventricles and lungs were evaluated after bolus intravenous injection of 99mTc-human serum albumin in 512 preoperative patients and 551 post-operative patients. Omitting 31 cases of technical failure due to poor bolus, we detected shunts in 459 cases of 481 preoperative evaluations, so the detectability was 95.4%. The cases which couldn`t be detected by this method had small amount of shunt. Also the degree of shunt detected by radioisotope methods were well correlated with oxymetry method. [r=0.89, p<0.01 ] In postoperative evaluations, 18 out of 411 patients with left to right shunt and 10 out of 140 right to left shunt were found to have remnant shunts with radionuclide cardiac angiography. Of the 28 cases with failed operation, 2 were confirmed in reoperation, 2 by cardiac catheterization, 2 by two -dimensional echocardiography. All except one .f these patients had membranous ventricular septal defects and those with left to right shunts had moderate to severe pulmonary hypertension and shunt amount. Also those had larger septal defects than control group. We consider that radionuclide cardiac angiography is a simple and noninvasive method which can show the preoperative diagnosis and postoperative follow up of cardiac shunts.

• Journal of Chest Surgery
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• 제21권1호
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• pp.10-16
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• 1988

Ten patients with tetralogy of Fallot were studied angiocardiographically before a modified Blalock-Taussig shunt and again 25*3.2 months after the previous shunt. All of ten patients had patent previous shunt at the time of follow up examination. Pre-and postoperative diameters of left and right pulmonary artery and descending aorta were measured and pulmonary artery index [the sum of the crossectional areas of the right and left pulmonary arteries standardized by the body surface area] was calculated. The ratio of mean diameter of left and right pulmonary arteries to the diameter of the descending aorta [LPA+RPA/2xDA] was increased postoperatively by 0.20*0.068 [p=0.020]. Mean PAI [pulmonary artery index] increased from 283.8*178.4 mm/m2 BSA to 345.8~144.5 mm/m2 BSA after shunt operation [p=0.019]. This results suggested that the modified Blalock-Taussig shunt was effective to help growth of the pulmonary arteries in most cases of the study populations but the ones with the PAI>233mm*/m* BSA appeared less benefited by Blalock Taussig shunt. Calculation of PAI could be an aid to making a decision whether to perform a one stage corrective surgical procedure or a palliative shunt procedure in the patient with small pulmonary arteries.

• Journal of Chest Surgery
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• 제16권1호
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• pp.91-96
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• 1983

A study was carried out to observe the clinical progress and results after modified Blalock-Taussing shunts on II patients with cyanotic complex heart diseases unsuitable for corrective surgery. The operation was performed by interposing a vascular prosthesis [PTEE] between the left subclavian artery and the left pulmonary artery. Vascular prostheses larger than the diameter of left subclavian artery were selected. The results were as follows: 1. The postoperative courses in 10 patients were uneventful without any complications. One patient died of low cardiac output syndrome immediate postoperatively. 2. The average value of RBC count before operations was 751.2291.68 [xl00]/cubic mm. It was decreased to 588.11 90.45 [xl 0,000]/cubic mm. After the operation. 3. The average value of Hemoglobin before operations was 20.07 3.01 mg/dl. The value was decreased to 15.361.68mg/dl after the operation. 4. The value of Hematocrit before operations was 62.878.89%. The value was decreased to 49.6 5.84% 5. Patency after the shunt operations using PTFE was good for maximal 16 months follow-up period. 6. The physiological impairment like anoxic spells, degree of cyanosis and other clinical symptoms were markedly improved after the shunt operations. Although a longer follow-up seems to be necessary to assess the validity of these shunts, the early results were encouraging.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.184-186
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• 2003

As STATCOM is considered to be installed in bulk power system, various studios are conducted to establish strategies for system operation considering STATCOM. This paper describes control strategy for coordinating STATCOM with existing switched shunt in bulk power system.

• Clinical and Experimental Pediatrics
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• 제49권10호
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• pp.1106-1110
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• 2006

유미성 복수는 복강이나 후복강의 림프순환계에 이상이 발생하는 질환이나 각종 원인에 의해서 발생하는 드문 질환으로서, 대개 혈장 내 triglyceride보다 2-8배 이상의 높은 복수 내 triglyceride의 함량을 보이는 경우 진단이 가능하다. 유미성 복수는 여러 가지 원인에 의해서 발생할 수 있지만, 수술 후 부작용으로서 복강이나 후복강 및 종격동의 수술 후 발생하는 경우가 드물게 있다. 저자들은 선천성 간섬유화증을 가진 소아 환자에서 비-신장 단락수술(Warren 단락술) 후에 발생하여 금식 및 총정맥영양에 이어 저지방식이를 시행한 후 호전된 유미성 복수증 1례를 경험하였기에 문헌고찰과 함께 이를 보고하는 바이다.

• 한국산학기술학회논문지
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• 제14권4호
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• pp.1765-1773
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• 2013

본 연구에서는 단순천공배액술을 시행하고 호전된 환자들과 이차 수술로 단순천공배액술을 실시하거나 경막하복강단락술을 실시한 환자들의 임상적 경과 분석을 통해 뇌경막하수종 치료에 도움이 되고자 한다. 2006년 7월부터 2012년 6월까지 본원에서 뇌경막하수종으로 입원하여 단순천공배액술을 시행받은 16례 전체 환자를 대상으로 분석하였다. 연구결과 아스피린을 복용하고 있는 환자는 모두 이차 수술을 시행하였다(p<0.001). 경막하복강단락술을 시행한 환자 4명 중 2명이 아스피린을 복용하여 통계적으로 유의하였다(p=0.014). 경막하복강단락술을 시행한 그룹과 시행하지 않은 그룹 간의 비교 결과, 4명의 환자는 일차수술 후 GCS의 변화는 없었으나 추적 전산화단층촬영 상 정중선 편위가 심하였고 경막하수종은 증가하거나 변화가 없었으며 두통, 구토, 발열, 호흡곤란 등의 뇌압상승 증상을 보여 단락술을 결정하게 되었다(p=0.006). 아스피린을 복용했던 환자들의 수술적 치료는 주의를 요하며 개두술 과정에서 뇌척수액의 급격한 소실과 뇌압의 지나친 변화를 예방하는 것이 중요하다고 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.9-11
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• 2003

In power system planing and operation, voltage and reactive power control are very important. The voltage deviation and system losses can be reduced through control of reactive power sources. In general, there are several different reactive power sources, we used UPFC and switched shunt capacitor to improve the voltage profile and to reduce system losses in this study. Since there are many switched shunt capacitors in power system, so it is necessary to coordinate these switched shunt capacitors. In this study, Genetic Algorithm(GA) is used to find optimal coordination of UPFC and switched shunt capacitors in a local area of power system. In case study, the effectiveness of the proposed method is demonstrated in KEPCO's power system. The simulation is performed by PSS/E.