• Journal of Chest Surgery
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• v.31 no.9
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• pp.827-836
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• 1998

Background: Effective cardiopulmonary resuscitation (CPR) should provide acceptable hemodynamics for the vital organs during cardiac arrest and early restoration of spontaneous circulation that guarantees long-term, neurologically intact survival. CPR using heart-lung bypass has been suggested as an option for that use. This study was designed to determine the effectiveness of standard CPR techniques, closed-vs. open-chest CPR, which could be used in the future study verifying the role of heart-lung bypass CPR. Material and Method: By using adult mongrel dogs, closed-chest CPR (CCCPR, n=4) and open-chest CPR (OCCPR, n=5) were compared with respects to hemodynamics, restoration of spontaneous circulation(ROSC), and survival. Ventricular fibrillation-cardiac arrest (VF-CA) was induced by electrical shock in all animals. After 4 minutes of cardiac arrest, basic life support (BLS) was applied for 15 minutes and followed by advanced life support (ALS). ALS was maintained until achi ving ROSC but not longer than 30 minutes regardless of the recovery. Resuscitation procedures in either group were standardized by adopting the protocol of American Heart Association. Result: Prearrest baseline hemodynamic data was not different between two groups. During resuscitation, substantially higher systolic pressure was maintained in OCCPR group than in CCCPR group (45$\pm$15 vs. 33$\pm$11 mmHg during BLS, 83$\pm$36 vs. 44$\pm$15 mmHg during ALS; p=NS). Mean pulmonary arterial pressure went up to the level of mean systemic arterial pressures in CCCPR group and to half of that in OCCPR group, and had kept higher in CCCPR group throughout CPR (32$\pm$10 vs. 22$\pm$4 mmHg during BLS and 32$\pm$15 vs. 24$\pm$10 mmHg during ALS; p=NS). ROSC was obtained in 4 of 5 dogs receiving open-chest CPR and 2 of 4 closed-chest CPR. Prolonged survival was noted in all dogs in OCCPR group (6 to 1440 hours) but not in CCPR group (p<.05). Conclusion: These findings indicate that open-chest CPR can be more effective t maintain hemodynamics during cardiac arrest and to obtain restoration of spontaneous circulation and survival. Further experiment will be designed to compare heart-lung bypass CPR with open-chest CPR.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.567-572
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• 1999

Background: Surgical correction of the full spectrum of esophageal atresia with tracheoesophageal fistula has improved over the years, but the mortality and morbidity assoiated with repair of these anomalies still remains high. Material and Method: We retrospectively analyzes 27 surgically treated patients with esophageal atresia and tracheoesophageal fistula at Dong-A University Hospital between January 1992 and March 1997. Result: There were 21 male and 6 female patients. Mean birth weight was 2.62$\pm$.385 kg(2.0~3.4 kg). Twenty- four(88.9%) had esophageal atresia with distal tracheoesophageal fistula, and 3(11.1%) had pure esophageal atresia. Four(14.8%) infants were allocated to Waterston risk group A, 18(66.7%) to group B, and 5(18.5%) to group C. In eighteen(66.7%) infants with associated anomalies, cardiovascular anomalies were the most common. Three had a gap length of 3.5 cm or greater(ultra-long gap) between esophageal segments, 7 had 2.0 to 3.5 cm(long gap), 8 had 1.0 to 2.0 cm(medium gap), and 9 had 1 cm or less(short gap) gap length. Among 27 neonates, 3 cases underwent staged operation, late colon interposition was done in 2, and all other 24 cases underwent primary esophageal anastomosis. Oerative mortality was 2/27(7.4%). Causes of death included acute renal failure(n=1), empyema from anastomotic leak(n=1), necrotizing enterocolitis(n=1), sepsis(n=1), insulin-dependent diabetus mellitus(n=1 . There were 4 anastomosis- related complications including stricture in 3, leakage in 1. Mortality was related to the gap length(p<.05). Conclusion: Although the complication rate associated with surgical repair of these anomalies is high, this does not always implicate the operative mortality. The overall survival can be improved by effective treatment for combined anomalies and intensive postoperatve care.

• Solar Energy
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• v.7 no.1
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• pp.42-52
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• 1987

파형 단면을 가진 유하식 집열기의 이론 및 실험 결과로서 유량, 각도등 집열성능에 미치는 영향등이 고려되었다. 입구 온도와 출구온도 차이가 적을 경우에는 이론과 실험치가 잘 맞으나 온도차이가 많을 경우 혹은 입구온도가 높을 때에는 투과체안에 생기는 결로 및 수증기의 영향으로 편차가 커진다. 개방회로와 폐쇄회로의 경우를 구분하여 실험되었는데 개방회로의 경우 효율은 약간 저하되지만 전반적인 성능은 폐쇄회로와 같은 경향을 나타내었다. 개방회로는 과열을 막는 방편으로 이용될 수 있다.

• Journal of Biomedical Engineering Research
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• v.23 no.4
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• pp.309-315
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• 2002

Since the discovery, in the 1980s, of erosion-pit-induced fractures in implanted mechanical heart valves. cavitation on the surface of mechanical heart valves has been widely studied as a possible cause of pitting. Several factors, including peak dp/dt of the ventricular pressure. maximum closing velocity of the leaflet, and squeeze flow. have been studied as indices of the cavitation threshold. In the present study. cavitation erosion on the surface of a mechanical valve was examined by focusing on squeeze flow and the water hammer phenomenon during the closing period of the valve. In this study, we measures pressure wave forms near a valve and closing velocities of a disk, which were placed in a holder with and without compliance. In case of all holders, pressure drop of below vapor pressure expect at near the surface disk. It was also found that the closing velocity of the disk increased and that cavitation erosion was enhanced too. These results suggest that disk closing velocity during the closing phase has signifiant effects on pitting erosion.

• 도로교통
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• s.97
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• pp.14-27
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• 2004

도로에 있어 교통량이 일정한 수준을 초과하여 증가되는 경우 통행시간과 운행비용이 과도하게 증대되는 혼잡현상이 발생하게 된다. 이러한 혼잡은 경제적 관점에서 추가분의 통행자가 기존 이용자의 통행비용을 증가시키는 유형으로 해석되고 있고, 이에 대한 대응으로 많이 사용되어 왔던 방법이 개별 통행자에게 다른 이용자들의 통행비용 증가분에 상응하는 요금을 혼잡통행료로서 부과하는 방법이다. 이와 같은 혼잡통행료는 국내의 경우 도심부로 진입하는 특정 도로에 국한하여 시행되는 것을 일반적인 것으로 인식하고 시행해왔으나(서울시 남산1, 3호 터널) 국외의 경우에는 환경보호 및 수요조절 측면에서 고속도로까지 확대 시행하고 있는 사례를 찾아볼 수 있다. 이에 본 연구에서는 국내의 고속도로 요금체계 현황에서 혼잡 통행료의 도입방안 및 가능성을 검토하고자 한다. 고속도로의 현행 통행료 부과 방법 및 제도를 고려할 때 통행요금에 혼잡통행료를 도입할 경우 1)시간대별 차등요금제, 2)폐쇄식 및 개방식 구간에서의 차등요금제, 3)노선별, 구간별 차등요금제, 4)요일별, 계절별 차등요금제를 고려할 수 있다. 현재의 고속도로에서 혼잡통행료를 도입할 경우 현행 이부요금제의 주행요금에 혼잡통행료 개념을 도입하는 것이 타당할 것으로 검토된다. 시간대별 차등요금제는 그 시간대를 주간(06시~24시)과 야간(24시~06시)으로 구분함이 타당할 것으로 판단되고 폐쇄식 구간의 경우 혼잡도를 고려한 주행요금을 이용거리에 비례하여 부과하며 개방식 구간의 경우 최단 이용거리를 기준으로 혼잡도를 고려한 주행요금을 부과하는 것이 타당할 것으로 판단된다. 또한 혼잡도를 고려한 주행요금을 부과하는데 있어 노선별, 구간별 차등을 두는 것이 바람직할 것으로 기대된다. 그러나 요일별 차등요금제는 주 5일 근무제가 확산됨에 따라 증가하는 비업무 승용차의 통행에 의해 고속도로의 비효율적인 운영이 발생할 경우를 제외하고는 적용하지 않는 것이 타당할 것으로 검토된다.

• Fire Science and Engineering
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• v.33 no.2
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• pp.79-84
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• 2019

The use of emergency escape breathing devices (EEBD) is strongly required to protect against toxic gas or flooding caused by ship fires or accidents. Recently developed domestic EEBD products only satisfy the basic performance requirements, but no wear fit and activity performance evaluation has been done for real usage. In this study, the global level test requirements for wear comfort and activity of EEBDs were developed and the open and closed type of domestic EEBD products were evaluated. Poor visibility, longer wear time, breathing resistance, and hose obstruction in an open type and canister obstruction, weight unbalance, and an invisible black breathing bag in the closed type EEBD were estimated to be the main problems that need to be improved.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.236-240
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• 1997

The management of neonate with long gap atresia without a fistula(type A) is complex and controversial. Various esophageal reconstruction include use of native esophagus or replacement with colon, stomach and small bowel. A severe premature male, at 28 weeks gestation weighing 1.2kg, was born with type A esophageal atresia in Chonnam University Hospital. Initial treatment consisted of gastrostomy under the local anesthesia and suctioning of proximal pouch, and than underwent delayed esophageal end to end anastomosis. A minimal leakage and mediastinitis ocurred postoperatively, but was treated by adequate drainage and negative suction from the leakage site through the gastrostomy. The patient was discharged in good general condition and normal weight of 5.4kg after 4 months after the surgery.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.643-647
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• 2006

Congenital tracheomalacia associated esophageal atresia is a rare foregut anomaly. We report a case of 40-day old male infant with tracheomalacia who has undergone repair of esophageal atresia at his age of 1 day. The patient had progressive dyspnea and stridor after repair of esophageal atresia. His 3-dimensional chest computed tomography showed severe stenosis at the middle of trachea. We underwent resection and end-to-end anastomosis under cardiopulmonary bypass. Histologic examination revealed esophageal tissues indicating congenital origin as well as no cartilage.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.765-769
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• 2007

Background: The curative treatment of choice for empyema is decortication of the pleura. The risks of this treatment however are increased for the patient with reduced pulmonary function, complicated calcification or septic shock. In the past, open window thoracostomy was a final stage treatment for chronic empyema. Relatively safe treatment of empyema could be achieved in difficult cases with a closure of the open window after open drainage and use of a myocutaneous flap (one stage or staged). Material and Method: A retrospective study of the cause, progression and final outcome of empyema patients who received open window thoracostomy was performed. 21 patients were followed from 1995 to 2004 in the department of Thoracic and Cardiovascular Surgery in the College of Medicine, Pusan National University. Result: The average age of the patients was $57.5{\pm}15.5$ years (range $25{\sim}78$ years), of whom 16 (76.2%) were men and five (23.8%) were women. Pulmonary function test results showed an average FEV1 of $1.58{\pm}0.49 L$. The type of empyema was tuberculous empyema in 13 cases (61.9%), aspergillosis in three cases (14.3%), parapneumonic empyema in three cases (14.3%) and post-resectional empyema in two cases (10%). Bronchopulmonary fistula was seen in 14 cases. Eight cases were complicated by severe calcification of the pleura. For the four cases of bronchopulmonary fistula, the patients' serratus anterior muscle was covered in their first operation. The average number of ribs resected was $4{\pm}1$. Closure of the open window thoracostomy was performed in 12 cases. The average time to closure after open drainage was $10.22{\pm}3.11$ months and the average defect of the empyemal cavity before the final operation was $330{\pm}110 cc$. Among the 12 cases, there were two cases of spontaneous closure. In two cases closure was only achieved by using the reserved skin fold during the first surgery. Of the remaining eight cases, in seven we used the myocutaneous flap (four cases of lattisimus dorsi muscle and three cases of pectoralis major muscle), and in one case we used soft tissue. As regards complications of the closure, tissue necrosis occurred in one case, which led to failed closure, and there was one case of abdominal hernia in the rectus abdominis muscle flap. One patient died within 30 days of the surgery and one patient died of metastatic cancer. Conclusion: A staged operation with a final closure using open window thoracostomy, which consists of open drainage, transposition of the muscle and a myocutaneous flap, can be a safe and effective option for the chronic empyema patient who is difficult to cure with traditional surgical methods.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.30-33
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• 2003

최근 건강에 대한 인지도가 높아감에 따라 농산물의 안정성 요구도가 증가되고 있으며 환경농업의 필요성이 크게 대두되고 있고, 서구식 식문화의 급속한 도입으로 패스트푸드 식품과 육류 소비량의 증가로 신선채소의 소비가 증가되고 있는데 이에 따른 생산비 절감과 안정생산 기술이 요구되고 있다. 따라서 양액 공급에 따른 전력 등 에너지가 필요치 않고 일종의 폐쇄식 수경재배 방법으로써 작물이 주위 환경에 따라 양수분 흡수량이 다르므로 모세관 현상으로 배지내의 수분이 작물의 흡수한 만큼 공급되어 이용되고 배액이 없으므로 공해의 염려가 없고 고품질 채소의 저비용 생산이 가능한 새로운 모관양액공급시스템을 이용하여 양액공급시스템의 효율성을 검정하고 네트멜론과 몇 가지 엽채소의 생육특성을 구명코자 수행하였다. (중략)