• The Korean Journal of Financial Management
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• v.10 no.1
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• pp.249-280
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• 1993

Recent financial theory views insurance policies as financial instruments that are traded in markets and whose prices reflect the forces of supply and demand. This article analyzes individual's insurance purchasing behavior along with capital market investment activities, which will provide a more realistic look at the tradeoff between insurance and investment in the individual's budget constraint. It is shown that the financial economic concept of insurance cost should reflect the opportunity cost of insurance premium. The author demonstrates the importance of riskless and risky financial assets in reaching an equilibrium insurance premium. In addition, the paper also investigates how the investment income could affect the four established theorems on traditional insurance literature. At the present time in Korea, the price deregulation is being debated as the most important current issue in insurance industry. In view of the results of this paper, insurance companies should recognize investment income in pricing their coverage if insurance prices are deregulated. Otherwise. price competition may force insurance companies to restrict coverage or to leave the market.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.3.2-3
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• 1981

This paper was attemped to analize 55 cases of fiberoptic bronchoscopy during period of 3 years from Feb. 1978 till Feb. 1981 in Chung Ang University hospital. The results were as follow; 1) In age distribution; Most common age group was 5th decade (15 cases, 27.2%) and the other age groups showed relatively even distribution. 2) The ratio of male to female was 3 to 1. 3) The chief complaints were presented in following order; cough (52%), hemoptysis(25%), dyspnea(23.6%), chest pain(18%), chest disomfort(9%). 4) Direct smear of bronchoscopic aspiration material; Not found 33 cases (60%) were most common finding. In the founded bacteria Gram positive cocci 2 cases (3.6%), Gram negative cocci 2 cases (3.6%), Gram positive bacilli 1 cases (1.8%), Gram negativebacilli 2 cases (3.6%), mixed form 15 cases(27.2%) were presented. 5) Bacterial culture of bronchoscopic aspiration material; No growth 28 cases (50.9%) were most common finding. In the bacterial growth, alpha hemolytic streptococci 10 cases (18.2%), Neisseria group 7cases(12.7%), Klebsiella 2 cases (3.6%), Pseudomonas 2 cases (3.6%), mixed culture 6 cases (10.9%) were presented, 6) The diagnosis of bronchoscopic appearance, laboratory exam., and pathologic exam. of biopsed specimen were 21 cases (38.1%) primary carcinoma of bronchus, 8 cases (14.5%) pulmonary tuberculosis, 7 cases (12.7%) bronchitis in orders.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.142-149
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• 2003

To know the feasibility of the coronary artery bypass graft (CABG) for multivessel coronary artery disease with purely bilateral internal thoracic arteries (ITAs), we analyzed the short-term clinical results and the coronary angiography of the patients. Material and Method: From March 2001 to June 2002, four hundred and five patients underwent CABG. Purely bilateral ITAs were used in 159 patients (39.3%). We analyzed these patients retrospectively The mean age of these patients was $61.2{\pm}8.5$ (range: 30 ~80) years and there were 123 male patients. The preoperative risk factors were as follows: diabetes in 54 patients (34.0%), history of acute myocardiac infarction within 4 weeks in 29 (18.2%), and emergency operation in 6 (3.8%). Off-pump CABG was carried out in 128 patients (80.5%). Associated procedures were mitral valvuloplasty (5), aortic valve replacement (3), Dor procedure (1), and so on. Result: The mean number of distal anastomoses was $3.1{\pm}0.9$ (range: 2~6), the mean duration of hospital stay was $8.4{\pm}4.5$ days. There was one (0.6%) operative death. Except for one early death, no other patients suffered from low cardiac output. The other postoperative complications were occurred as follows: reoperation due to bleeding in 3 patients, perioperative myocardiac infarction in 1, transient cardiac arrest in 2, transient cognitive dysfunction in 7, and transient ischemic attack in 1, and deep sternal wound infection in 1 patient. Recently, early postoperative angiography was performed in 19 patients who had triple vessel disease. The total number of distal anastomosis was 78 (mean $4.1{\pm}0.8$/patient). All distal anastomosis sites were patent, but competition flow was observed at the bypass sites where the native coronary artery stenosis was not significant. Conclusion: The CABG with purely bilateral ITAs for triple vessel disease was performed safely. The early patency rate was relatively good in small number of patients. However the long-term patency rate and the functional study to evaluate the sites where competition flow was observed should be followed.

• Journal of Chest Surgery
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• v.39 no.9 s.266
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• pp.681-691
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• 2006

Background: The aim of this study was to investigate the mid-term outcomes of our modifications to the maze procedure using cryoablation for treating atrial fibrillation associated with rheumatic mitral valve disease. Material and Method: Between March 2000 and February 2004, 177 consecutive patients underwent the modified maze procedure with the use of cryoablation concomitant with mitral valve surgery for atrial fibrillation associated with rheumatic mitral valve disease, and were divided into three groups: (1) modified Cox-maze III (CM group, n=88): (2) modified Kosakai-maze (KM group, n=63): and (3) left atrial maze procedure (LA group, n=26). The postoperative and follow-up results were analyzed and compared between the groups. Result: There were three hospital deaths (1.7%) and no significant differences in the incidence of postoperative complications between the three groups. The operative time, such as the cardiopulmonary bypass and aortic crossclamp time, were significantly longer in the CM group than in the KM and LA groups, respectively (p<0.0001). The mean follow-up was $22.4{\pm}15.1$ months ($1\sim52.6$ months) for all patients. One late death developed in the CM group (0.0%). At last follow-up, 139 patients exhibited sinus rhythm (79.9%), which was also regained in 67 patients (77.9%) in the CM group, 50 (80.7%) in the KM group and 22 (84.6%) in the LA group (p=0.743). The actuarial freedom from stroke at 4 years was $84.5{\pm}9.4%$ in the CM group, $95.0{\pm}4.9%$ in the KM group, and $92.9{\pm}6.9%$ in the LA group (p=0.916). Conclusion: The modified maze procedure using cryoablation is safe and effective in treating chronic atrial fibrillation associated with rheumatic mitral valve disease.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.929-936
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• 2003

We analysed the surgical outcomes of immediate reoperations after mitral valve repair. Material and Method: Eighteen patients who underwent immediate reoperation for failed mitral valve repair from April 1995 through July 2001 were reviewed retrospectively. There were 13 female patients. The mitral valve disease was regurgitation (MR) in 12 patients, stenosis (MS) in 3, and mixed lesion in 3. The etiologies of the valve disease were rheumatic in 9 patients, degenerative in 8, and endocarditis in 1. The causes of reoperation was residual MR in 13 patients, residual MS in 4, and rupture of left ventricle in 1. Fourteen patients had rerepair for residual mitral lesions (77.8%) and four underwent replacement. Result: There was no early death. After mean follow-vp of 33 months, there was one late death. Echocardiography revealed no or grade 1 of MR (64.3%) in 9 patients and no or mild MS in 11 patients (78,6%). Reoperation was done in one patient. The cumulative survival and freedom from valve-related reoperation at 6 years were 94% and 90%, respectively. The cumulative freedom from recurrent MR and MS at 4 years were 56% and 44%, respectively. Conclusion: This study suggests that immediate reoperation for failed mitral valve repair offers good early and intermediate survival, and mitral valve rerepair can be successfully performed in most of patients. However, because mitral rerepair have high failure rate, especially in rheumatic valve disease, adequate selections of valvuloplasty technique and indication are important to reduce the failure rate of mitral rerepair.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.31-38
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• 2008

Ad-Hoc network is a network architecture which has no backbone network and is deployed temporarily and rapidly in emergency or war without fixed mobile infrastructures. All communications between network entities are carried in ad-hoc networks over the wireless medium. Due to the radio communications being extremely vulnerable to propagation impairments, connectivity between network nodes is not guaranteed. Therefore, many new algorithms have been studied recently. This study proposes the secondary header approach to the cluster based routing protocol (CBRP). The primary header becomes abnormal status so that the primary header can not participate in the communications between network entities, the secondary header immediately replaces the primary header without selecting process of the new primary header. This improves the routing interruption problem that occurs when a header is moving out from a cluster or in the abnormal status. The performances of proposed algorithm ACBRP(Advanced Cluster Based Routing Protocol) are compared with CBRP. The cost of the primary header reelection of ACBRP is simulated. And results are presented in order to show the effectiveness of the algorithm.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.598-604
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• 2008

Background: The improvements in endoscopic equipment and surgical robots has encouraged the performance of minimally invasive cardiac operations. Yet only a few Korean studies have compared this procedure with the sternotomy approach. Material and Method: Between December 2005 and July 2007, 48 patients (group A) underwent minimally invasive cardiac surgery with AESOP through a small right thoracotomy. During the same period, 50 patients (group B) underwent conventional surgery. We compared the operative time, the operative results, the post-operative pain and the recovery of both groups. Result: There was no hospital mortality and there were no significant differences in the incidence of operative complications between the two groups. The operative $(292.7{\pm}61.7\;and\;264.0{\pm}47.9min$, respectively; p=0.01) and CPB times ($128.4{\pm}37.6\;and\;101.7{\pm}32.5min$, respectively; <0.01) were longer for group A, whereas there was no difference between the aortic cross clamp times ($82.1{\pm}35.0\;and\;87.8{\pm}113.5min$, respectively; p=0.74) and ventilator times ($18.0{\pm}18.4\;and\;19.7{\pm}9.7$ hr, respectively; p=0.57) between the groups. The stay on the ICU $(53.2{\pm}40.2\;and\;72.8{\pm}42.1hr$, respectively; p=0.02) and the hospitalization time ($9.7{\pm}7.2\;and\;14.8{\pm}11.9days$, respectively; p=0.01) were shorter for group A. The Patients in group B had more transfusions, but the difference was not significant. For the overall operative intervals, which ranged from one to four weeks, the pair score was significantly lower for the patients of group A than for the patients of group B. In terms of the postoperative activities, which were measured by the Duke Activity Scale questionnaire, the functional status score was clearly higher for group A compared to group B. The analysis showed no difference in the severity of either post-repair of mitral ($0.7{\pm}1.0\;and\;0.9{\pm}0.9$, respectively; p=0.60) and tricuspid regurgitation ($1.0{\pm}0.9\;and\;1.1{\pm}1.0$, respectively; p=0.89). In both groups, there were no valve related complications, except for one patient with paravalvular leakage in each group. Conclusion: These results show that compared with the median sternotomy patients, the patients who underwent minimally invasive surgery enjoyed significant postoperative advantages such as less pain, a more rapid return to full activity, improved cosmetics and a reduced hospital stay. The minimally invasive surgery can be done with similar clinical safety compared to the conventional surgery that's done through a median sternotomy.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.249-254
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• 1999

Background: Recovery of the left atrial contractile function after the Cox-Maze procedure is related to the size of the left atrium. We have postulated that if too wide area of the atrium were isolated electrically, then the atrial contractile function would be impaired postoperatively. We have modified the Cox-Maze procedure to dissect each pair of the pulmonary veins separately instead of the conventional pulmonary vein encircling incision, and compared the atrial contractile function after each procedure. Material and Method: From February 1995 to October 1997, 55 cases of the Cox-Maze procedure were performed in mitral valvular heart disease. We excluded the cases that did not covert to sinus rhythm. The patient groups were divided according to the interpulmonary vein distance(IPVD) and the procedure performed. Group I was IPVD under 6.5 cm(n=30), group II was IPVD over 6.5cm and the conventional Cox-Maze III procedure was performed(n=16), and group III was IPVD over 6.5cm and the modified Cox-Maze procedure was performed(n=9). Result: Atrial contractile function was evaluated by the echocardiography follow-up between 6 months to 12 months. The right atrial contractile function recovered gradually, the recovery rate after long-term follow-up was 90% in group I, 81% in group II, and 100% in group III(p>0/05). In the left atrium the recovery rate was 63% in group I, 31% in group II(p=0.03), and 66% in group III(p>0.05). Conclusion: The modified Cox-Maze procedure may have beneficial effects on the recovery of the left atrial contractile function, however, there are no statistically significant values. Therefore, further evaluation of this procedure is necessary.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.643-652
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• 2002

As the prevalence of coronay artery disease is increasing, the surgical treatment has been universalized and operative outcome has been improved. We analyzed the short and mid-term results of 292 CABGs performed in Kangdong Sacred Heart Hospital. Material and Method: From June 1994 to December 2001, 292 patients underwent coronary artery bypass grafting. There were 173 men and 119 women and their ages ranged from 39 to 84 years with a mean of $61.8{\pm}9.1$ years. We analyzed the preoperative risk factors, operative procedures and operative outcome. In addition, we analyzed the recurrence of symptoms, long-term mortality and complications via out-patient follow-up for discharged patients. Result: Preoperative clinical diagnoses were unstable angina in 137(46.9%), stable angina in 34(11.6%), acute myocardial infarction in 40(13.7%), non-Q myocardial infarction in 25(8.6%), postinfarction angina in 22(7.5%), cardiogenic shock in 30(10.3%) and PTCA failure in 4(1.4%) patients. Preoperative angiographic diagnoses were three-vessel disease in 157(53.8%), two-vessel disease in 35 (12.0%), one-vessel disease in 11(3.8%) and left main disease in 89(30.5%) patients. We used saphenous veins in 630, internal thoracic arteries in 257, radial arteries in 50, and right gastoepiploic arteries in 2 distal anastomoses. The mean number of distal anastomoses per patient was $3.2{\pm}1.0$ There were 18 concomitant procedures ; valve replacement in 8(2.7%), left main coronary artery angioplasty in 6(2.1%), patch closure of postinfarction ventricular septal defect(PMI-VSD) in 2(0.7%), replacement of ascending aorta in 1(0.3%) and coronary endarterectomy in 1(0.3%) patient. The mean ACC time was $96.6{\pm}35.3 $ minutes and the mean CPB time was $179.2{\pm}94.6$ minutes. Total early mortality was 8.6%, but it was 3.1% in elective operations. The most common cause of early mortality was low cardiac output syndrome in 6(2.1%) patients. The stastistically significant risk factors for early mortality were hypertension, old age($\geq$ 70 years), poor LV function(EF＜40%), congestive heart failure, preoperative intraaortic balloon pump, emergency operation and chronic renal failure. The most common complication was arrhythmia in 52(17.8%) patients. The mean follow-up period was $39.0{\pm}27.0$ months. Most patients were free of symptoms during follow-up. Fourteen patients(5.8 %) had recurrent symptoms and 7 patients(2.9%) died during follow-up period. Follow-up coronary angiography was performed in 13 patients with recurrent symptoms and they were managed by surgical and medical treatment according to the coronary angiographic result. Conclusion: The operative and late results of CABG in our hospital, was acceptable. However, There should be more refinement in operative technique and postoperative management to improve the results.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.749-755
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• 1998

Background: Twelve patients with acyanotic tetralogy of Fallot(TOF), characterized by the combination of a malaligned ventricular septal defect(VSD) and infundibular pulmonic stenosis with the clinical finding of acyanosis at rest, underwent surgical correction between January 1988 and July 1997. Materials and methods: 9.92% of patients with the diagnosis of TOF were acyanotic TOF in the same period. Ages ranged from 12 to 42 months(mean 25.2 months). 2D-echocardiographic studies, cardiac catheterization, and angiocardiograms were performed in all patients before operation. The preoperative mean systemic arterial oxygen saturation was 93.5%. According to the 2D-echocardiographic analysis, there was Lt-to-Rt shunt through VSD in 4 patients, bidirectional shunt in 2 patients, and no shunt in 6 patients. Results: The preoperative mean right ventricle to pulmonary artery(RV-PA) pressure gradients were 52.3 mmHg on 2D- echocardiogram and 48.4 mmHg on cardiac catheterization. The repair of ventricular septal defect was performed through a right atrial approach and the hypertrophic infundibular muscle bundles were resected by the transatrial and transpulmonary approach. Six patients(50%) received a transannular patch. The mean cardiopulmonary bypass time was 135.0 minutes, and the aortic crossclamp time was 87.8 minutes. Postoperative complications included bleeding necessitating reentry in one and chylothorax in one. No patient died after operation and there were no late deaths. Postoperative 2D-echocardiograms revealed tiny patch dehiscence in 5 cases and a moderate RV-PA pressure gradients(mean 15.3 mmHg). All patients were in New York Heart Association functional class 1 after operation. Conclusions: acyanotic TOF is the uncommon form of TOF, and acyanotic TOF can be repaired with a good outcome.