• The Korean Journal of Applied Statistics
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• v.19 no.2
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• pp.369-377
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• 2006

This paper considers moving variance ratio (MVR) for valiance detection problem with time series data in progress. For testing purpose, parametric method based on F distribution and nonparametric method based on empirical distribution are compared via simulation study.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.218-221
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• 1982

Delayed cardiac tamponade in an uncommon and frequently fatal complication after open-heart surgery. We had been experienced two cases of delayed cardiac tamponade as a complication of open-heart surgery and treated successfully by reinsertion of pericardial drain through subxiphoid route. First case was 60 years old female patient and underwent MVR under impression of MSi + Ti Second case was 19 years old male patient and underwent total correction of T.O.F.with Blalock shunt [Lt]. Both cases had Initial symptoms, which were epigastric pain, chest tightness, dropped blood pressure, and increased pulse rate and respiratory rate, mimic as low cardiac output syndrome after open-heart surgery. Roentgenogram of the chest showed a rapid increased cardiothoracic ratio. It is important to realize the presence of late cardiac tamponade for proper diagnosis of complication after open-heart surgery.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.254-258
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• 1982

We have experienced one case of Redo AVR which was performed 13 months after initial operation. The patient had received AVR [Bjork-Shiley disc valve] and MVR [Ionescu-Shiley tissue valve] because of ASI and MSI at March, 1981. During follow up through the OPD, he complained exertional dyspnea and progressive jaundice with hemolytic anemia was also noticed since 1 month prior to readmission. Cardiac catheterization and angiography revealed periaortic valvular leakage due to partial detachment of previously replaced prosthetic aortic valve. Re-replacement of prosthetic aortic valve with Ionescu-Shiley valve was performed and the patient was discharged at 17th POD without any complications.

• Journal of Chest Surgery
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• v.17 no.1
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• pp.3-11
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• 1984

Prosthetic valve replacement has resulted in marked improvement in the functional status of many patients with valvular heart disease. But valve failure from various causes has necessitated re-replacement of prosthetic valve in some of these patients. This selective group of patients has many inherent problems. This report presents our experience with seven patients who received re-replacement of prosthetic valve in the Seoul National University Hospital from 1981, to 1983. The patients included one woman and six men in the range of 9 and 49 years old. As the first valve operations, there were five MVR using tissue valves, one DVR [Bjork-Shiley and Ionescu-Shiley valve] and one case of modified Bentall operation with composite graft [Ionescu-Shiley valve]. Reoperations on prosthetic valve failure were performed 17 to 54 months after the first operation [mean 34 months]. Amon8 seven patients, there were two cases of prosthetic valve endocarditis and five cases of primary tissue failure. Gross calcification of the xenograft was found in two children with Ionescu-Shiley valve. All except one had relatively successful operative results. The unsuccessful one died intraoperatively from low output syndrome.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.305-314
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• 1984

From May 1977 to April 1984, 204 cases of open heart surgery were performed under cardiopulmonary bypass. There were 99 male and 105 female patients ranging in age from 19 months to 58 years. 136 cases [66.7%] were congenital heart disease, and 68 cases [33.3%] were acquired heart disease, which were 66 valvular disease [97.1%], 1 IVC obstruction, and 1 myxoma. There were 136 congenital heart anomaly with 16 operative deaths [11.8%], consisting of 94 acyanotic cases with 7 death [7.4%] and 42 cases of cyanotic cases with 9 deaths [21.4%]. In 66 patients of acquired valvular disease, 52 valves were implanted; 47 mitral valve replacement with 4 death [8.5%] and 5 double valve replacement [MVR+AVR] with 1 death [20%]. Postoperative, warfarin sodium was medicated with checking prothrombin time. Finally, the operative mortality was 11.8% in congenital anomaly, and 11.8% in acquired heart disease, overall mortality rate was 8.5%.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.383-390
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• 1985

108 cases of open heart surgery were done at our department in 1984. There were 58 male and 50 female patients ranging in age from 20 months to 52 years. 75 cases were congenital heart disease, and 33 cases were acquired heart disease. There were 75 congenital heart anomalies with 5 operative deaths [6.7%], consisting of 62 acyanotic cases with 2 deaths [3.2%] and 13 cases of cyanotic cases with 3 deaths [23.1]. In 33 patients of acquired valvular disease, 29 valves were implanted; 20 mitral valve replacement with 2 death [10%], 2 aortic valve replacement with 1 death [50%], 2 double valve replacement [MVR+AVR] and 2 open mitral commissurotomy plus aortic valve replacement with no death. Postoperative, Warfarin sodium was medicated with checking prothrombin time. Finally, the operative mortality was 9.2% in congenital anomaly, and 9.1% in acquired heart disease, overall mortality rate was 9.3%.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.990-995
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• 1989

Since 1984, 24 patients underwent repair of atrioventricular septal defect. Nineteen had a partial defect and 5 had a complete atrioventricular septal defect. There were 9 men and 15 women, ranging in age from 1 to 50 years [mean age, 13.3 years]. Four patients had a Downs syndrome. Additional congenital heart defects were present in 11 patients. One patient had palliative operation prior to total correction. In partial defects, the primum atrial septal defect was closed with Xenomedica patch and the mitral valve was repaired with simple closure of the septal commissure. Central incompetence from annular dilatation was repaired by a local annuloplasty. In complete defect, the septal defects were closed with two patches except one. Operative mortality was 5% in partial defects and 60% in complete defects and low cardiac output was the commonest etiology. In a mean follow-up period of 27.9 months [range, 4 to 63 months] there were no late death and no instances of late-onset complete heart block. One patient required reoperation [MVR] for residual mitral regurgitation. The majority of patients were asymptomatic and mean postop. NYHA functional class was 1.2.

• Journal of the Korean Data and Information Science Society
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• v.16 no.2
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• pp.289-300
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• 2005

In this article quick variance change point (VCP) detection problem for time series is considered. For this variance VCP detector equipped with tuning parameters is proposed. A major tool for the detector is moving variance ratio (MVR) which monitors variance change of a given time series. Tuning process of detector is investigated via simulation, which shows that tuning parameters are critical in achieving sensitivity and adaptiveness of detector.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.59-65
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• 2004

Survivability of the general purpose warhead during the target impact was studied. We first simulated the penetration phenomena and temporarily defined the survivability of the warhead at the impact situation. Next we launched the warhead projectiles by using Counter Mass Gun(CMG) system against the simulated specific steel target. The recovered warheads were carefully investigated and the penetration behaviors were analyzed. As a result the warhead can be hardened efficiently to enhance the survivability with the help of CMG test ＆ analysis.

• Journal of Chest Surgery
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• v.22 no.3
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• pp.448-455
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• 1989

Till June 1988, We experienced 3 cases of single atrium at Dept. of Thoracic k Cardiovascular Surgery of National Medical Center. Case 1 was 26 years old female, and had single atrium associated with partial cleft in mitral anterior leaflet and PAPVC. Atrial septation with Dacron patch and MVR [I-S, 31 mm] were done, followed by TAP, De Vega. Postoperative course was good, OPD follow-up for about 4 years with normal physical activity and ordinary working. Case 2 was 4 years old female with single atrium alone. Atrial septation with pericardial patch. Good postoperative course and OPD follow-up for about 2 years with appropriate physical growth. Case 3 was 22 years old female, single atrium with complete cleft in the anterior and posterior mitral leaflet, and septal tricuspid cleft were identified. Atrial septation with polystan bovine pericardial patch and repair of mitral anterior cleft. Postoperatively, residual regurgitation of mitral and tricuspid valve, but tolerable in some limitation of physical activity.