• Journal of Chest Surgery
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• v.24 no.5
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• pp.445-450
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• 1991

Forty eight patients diagnosed as atrial septal defect, had been operated from April 1986 to December 1990 at the Department of Thoracic and Cardiovascular Surgery, Inha University Hospital, were analysed retrospectively. Of the 48 patients, 12 patients, were male and 36 patients were female, Their ranged from 8 months to 51 years old, and the mean was 18.0 years old. The proceeding two symptoms were exertional dyspnea and frequent upper respiratory infection. But 10 patients [20.8%] were asymptomatic. Electrocardiographic findings were regular sinus rhythm in 100.0%, RVH in 29.2%, incomplete RBBB in 27.1%, and first degree AV block in 2.1%. Hemodynamic studies were performed in 38 of 48 patients. Significant pulmonary hypertension[over 50mmHg in systolic pulmonary arterial pressure], which is the most serious risk factor, was developed in 4 patients[8.3%]. There was statistical significance between size of defect[cm2/BSA-M2] and systolic pulmonary arterial pressure[sPAP] retrospectively[p=0.036]. We could not find the correlationship between age and Qs % size. Anatomically, secundum type constituted 97.9%, in which 43 patients were PFO type[91.6%] and 3 patients were IVC type[6.3%]. 38 of 48 ASD patients were repaired with patch closure[72.9%] and remains were repaired with direct closure[27.1%]. The operative result was excellent except two cases of transient postoperative arrhythmia. There was no operative mortality.

• Journal of Chest Surgery
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• v.21 no.6
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• pp.996-1002
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• 1988

A clinical analysis was performed on 115 cases of -patent ductus arteriosus treated surgically during the period of 11 years from Aug. 1977 to Jul. 1988. at the Department of Thoracic and Cardiovascular Surgery, Chungnam National University Hospital. Among 115 cases, male was 38 and female was 77 and ages ranged 12 days to 27 years old with the average of 8 7/12 years. The major clinical symptoms on admission were frequent URI attack[77.4%], dyspnea on exertion[32.2%] and palpitation[13%]. On auscultation, continuous machinery murmurs were detected in 97 cases[84.3%] and loud systolic murmurs were detected in 18 cases[15.7%]. Preoperative electrocardiographic findings were as follows: LVH 59[51.3%], RVH 12[10.4%], BVH 16[13.9%] and WNL 28[24.3%]. Radiologically, there were increased pulmonary vascularity in 104[90.4%] and cardiomegaly 62[53.9%]. Cardiac catheterization were performed in 101 cases and mean systolic pulmonary arterial pressure was 49.84*29.7mmHg and mean Qp/Qs was 2.95k1.8. Methods of operation were multiple ligation in 96, division in 11 and transpulmonary arterial repair using cardiopulmonary bypass in 8. Complication were recannalization in 2, temporary hoarseness due to left recurrent laryngeal nerve paralysis in 3 and respiratory distress in 1 and overall mortality rate was 1.7%[2 cases].

• Journal of Chest Surgery
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• v.17 no.2
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• pp.244-249
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• 1984

Surgical treatment of partial endocardial cushion defect was accomplished in Feb. 1984 in this department. The 5 year old male patient had history of frequent upper respiratory tract infection and since his age of 3 years dyspnea on exertion and palpitation were noted but there were no cyanosis and clubbing. A thrill was palpable on the apex and grade IV/IV harsh systolic ejection murmur and diastolic murmur was audible on it. Liver was palpable about 3 finger breadths and no ascites. Chest X-ray revealed increased pulmonary vascularity, moderate cardiomegaly [C-T ratio; 0.69], and enlarged left atrium. EKG showed first degree heart block, RVH, LVH, and LAD. Echocardiogram showed paradoxical ventricular septal movement and abnormal diastolic movement of the anterior leaflet of mitral valve. Right heart catheterization resulted left to right shunt [Qp:Qs:2.1:1 ] and moderate pulmonary hypertension [60/40 mmHg]. Left ventriculogram showed mitral regurgitation [Grade III/IV] and filling of left atrium and right atrium nearly same time. Operative findings were: 1.Primum type atrial septal defect [3x2 cm] 2.Cleft on the anterior leaflet of mitral valve. 3.No interventricular communication and cleft of tricuspid valve leaflet. The mitral cleft was repaired with 4 interrupted sutures. The primum type atrial septal defect was closed with Dacron patch intermittently at endocardial cushion and continuously remainder. The post operative course was uneventful and discharged on 22nd postoperative day in good general conditions.

• Journal of Chest Surgery
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• v.18 no.2
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• pp.151-156
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• 1985

A clinical analysis was done on 50 cases of ventricular septal defect, operated from April 1981 to March 1984 at the department of Thoracic and Cardiovascular Surgery, School of Medicine, Keimyung University. Among 50 cases, 34 cases were males and 16 cases were females. Their age ranged from 1 to 26 years and the mean age was 9.7 years. The main symptoms at admission were frequent upper respiratory infection [50%], exertional dyspnea [42%] and palpitation [34%]. In anatomical classification by Kirklin, type I constituted 20%, type II 76%, type IV 4%. Associated congenital cardiac lesions were pulmonic stenosis [6 cases], patent foramen ovale [5 cases], aortic insufficiency [3 cases] and persistent left superior vena cava [1 case]. When a normal electrocardiogram pattern was present, Qp/Qs, Rp/Rs and pulmonary artery systolic pressure and Pp/Ps were relatively low. Among cases of above 1 cm2/M2 BSA in size of defect, Pp/Ps and pulmonary artery systolic pressure were increased than the cases of below 1 cm2/M2 BSA [P=0.01]. The postoperative right bundle branch block was occurred in 21 cases [75%] among 28 cases of right ventriculotomy approach. The operative mortality was 2% [1 case] among 50 cases and complication rate was 14% [7 cases].

• Journal of Chest Surgery
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• v.23 no.2
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• pp.253-259
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• 1990

Between January, 1970 and August, 1989, a total of 81 patients whose age were more than 20 years of life, received total correction for tetralogy of Fallot. This report analyzed 70 patients among them and excluded the remaining 11 patients whose clinical data could not be found. Their mean age was 25.750.39 years[range 20 \ulcorner50]. The clinical manifestations were cyanosis and clubbing [64 pts], frequent URI[40 pts], anoxic spell [19 pts], infective endo-carditis[4 pts], brain abscess[3 pts], pulmonary tuberculosis[3 pts] and CHF, chest tightness, nephrotic syndrome, left hemiplegia, and tamponade. The types of right ventricular outflow tract obstruction were combined[46 pts], pure infundibular [21 pts] and pure valvular[3 pts]. Associated cardiovascular anomalies were PFO [27 pts], ASDi8 pts], LSVC[8 pts], aortic regurgitation [5 pts], right aortic arch, coronary artery anomalies, PDA and dextrocardia. Hospital mortality was 5.7%. The causes of death ware low cardiac output [2 pts], aggravation of CRF[1 pts] and brain damage[1 pts]. There was one late death because of residual intracardiac shunt and congestive heart failure. During the follow-up period, 16 patients were lost and the remaining 49 patients were asymptomatic and leading normal lives. Residual intracardiac shunt was detected in 5 patients with radionuclide single pass study but all of them had Qp / Qs ratio less than 1.5.

• Journal of Chest Surgery
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• v.20 no.1
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• pp.106-111
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• 1987

Twenty eight patients with atrial septal defect operated on from May, 1983, to July, 1986 at the Department of Thoracic and Cardiovascular Surgery, Chungnam National University Hospital, were analyzed retrospectively. Among the 28 patients of atrial septal defect, 8 were male and 20 were female. Their ages ranged from 4.6 years to 52.5 years old with the mean of 15.3 years. The main clinical symptoms on admission were exertional dyspnea [82%], frequent respiratory infection [75%], palpitation [54%] and easy fatigability [25%]. Electrocardiographic findings were as follows: Regular sinus rhythm [100%], RVH [54%], RBBB [25%] and first degree of A-V block [4%]. Hemodynamic studies were performed in all cases and mean pulmonary systolic arterial pressure was 34.1*11.8mmHg. and mean Qp/Qs was 2.6*0.9. All 28 patients were operated under direct vision using extracorporeal circulation. 23 cases were secundum type defect and a single hole was found in 22 cases. The associated cardiovascular anomalies were found in 11 patients: ventricular septal defect in 3, patent ductus arteriosus in 1, partial anomalous pulmonary venous drainage in 2, mitral regurgitation in 2, tricuspid regurgitation in 1, anomalous left atrial septation in 1 and valvular pulmonary stenosis in 1. The defect closed directly in 22 cases and with patches in 6 cases. Postoperative complications were wound infection, arrhythmia bleeding, intracardiac patch detachment, pneumothorax and urethral injury. But there was no operative mortality.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.528-535
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• 1987

A clinical study was performed on 164 cases of PDA experienced at the Dept. of Thoracic and Cardiovascular Surgery of Pusan National University Hospital during 6 years from Jan. 1981 to Dec. 1986. It was shown that the PDA was a female-dominant heart disease [male to female ratio, 1:2.8] and two most common symptoms were frequent URI [45.6%] and exertional dyspnea [36.7%]. Continuous machinery murmurs were detected in 143 cases [87.2%], increased pulmonary vascularities [89.0%] and cardiomegalies [63.4%] by chest X-ray. The signs of LVH [43.9%], RVH [3.7%] and BVH [4.9%] were noted on the EKG. Cardiac catheterizations were performed on 67 out of 164 patients and the mean systolic pulmonary artery pressure was 48mmHg [range: 18-131mmHg] and the mean Qp/Qs was 3.1 [range:1.2-8.5] and Rp/Rs below 0.25 was 83.6%. Associated cardiac anomalies were VSD [7.9%], ASD [3.0%], pulmonary valvular stenosis [2.4%] and left persistent SVC [2.4%]. Operative methods were as follows; ligations [145; 88.4%] and divisions [6;3.7%] were performed through the left posterolateral thoracotomies without mortality and the remained cases [13;8.0%] were managed under the cardiopulmonary bypass because of the associated cardiac anomalies. Atelectasis [4.9%] and pneumonia [4.3%] were most frequent postoperative complications and the overall mortality rate was 2.4% [4 out of 164 cases].

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.778_779
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• 2009

The maximum output torque developed by the machine is dependent on the allowable current rating and maximum voltage that the inverter can supply to the machine. Therefore, to use the inverter capacity fully, it is desirable to use the control scheme considering the voltage and current limit condition, which can yield the maximum torque per ampere over the entire speed range. The paper is proposed maximum torque control of induction motor drive using adaptive learning neuro fuzzy controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d, q axis current $_i_{ds}$, $i_{qs}$ for maximum torque operation is derived. The proposed control algorithm is applied to induction motor drive system controlled adaptive learning neuro fuzzy controller and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the adaptive learning neuro fuzzy controller and ANN controller.

• Geomechanics and Engineering
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• v.15 no.6
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• pp.1193-1205
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• 2018

A footing located on slopes possess relatively lower bearing capacity as compared to the footing located on the level ground. The bearing capacity further reduces under seismic loading. The adverse effect of slope inclination and seismic loading on bearing capacity can be minimized by proving sufficient setback distance. Though few earlier studies considered setback distance in their analysis, the range of considered setback distance was very narrow. No study has explored the critical setback distance. An attempt has been made in the present study to comprehensively investigate the effect of setback distance on footing under seismic loading conditions. The pseudo-static method has been incorporated to study the influence of seismic loading. The rate of decrease in seismic bearing capacity with slope inclination become more evident with the increase in embedment depth of footing and angle of shearing resistance of soil. The increase in bearing capacity with setback distance relative to level ground reduces with slope inclination, soil density, embedment depth of footing and seismic acceleration. The critical value of setback distance is found to increase with slope inclination, embedment depth of footing and density of soil. The critical setback distance in seismic case is found to be more than those observed in the static case. The failure mechanisms of footing under seismic loading is presented in detail. The statistical analysis was also performed to develop three equations to predict the critical setback distance, seismic bearing capacity factor ($N_{{\gamma}qs}$) and change in seismic bearing capacity (BCR) with slope geometry, footing depth and seismic loading.

• Journal of Applied Reliability
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• v.4 no.2
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• pp.65-72
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• 2004

If a quality system is properly designed and implemented, it will be one of the most effective tools in the prevention of quality problems, as well as potential product liability incidents. The purpose of this research is to present how the quality system should developed and focuses more on what it should include for the sake of preventing unsafe products and design. Includings are descriptions on how a manufacturer can put a comprehensive procedures and processes for product safety and effort in place, and move their existing quality system to a new level.