• Journal of KIISE:Computer Systems and Theory
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• v.31 no.11
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• pp.643-657
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• 2004

The chordal ring based CC-NUMA system contains many links to transmit transactions between a local node and a remote node because of its structural characteristics. However, the inclination that the transactions concentrate on the ring link increases both the traffic of the ring link and the response time, which degrades the overall performance of the chordal ring based CC-NUMA system. In this paper we suggest a new remote cache replacement policy that considers both the number of total links and the number of ring links to traverse for the transactions. Our proposed replacement policy can balance data between the ring link and the chordal link properly because it reflects the characteristics of chordal ring based CC-NUMA system well.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.2
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• pp.105-115
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• 2002

Since NUMA architecture has to access remote memory an interconnection network determines the performance of CC-NUMA system Bus which has been used as a popular interconnection network has many limits to build a large-scale system because of the limited physical scalabilty and bandwidth Dual ring interconnection network composed of high speed point-to-point links is made up for resolving the defects of the bus for large-scale system But it also has a problem that the response latency is rapidly increased when many node are attached to snooping based CC-NUMA system with dual ring In this paper we propose a chordal ring architecture in order to overcome the problem of the dual ring on snooping based CC-NUMA system and design and efficient link controller adopted to this architecture. We also analyze the effects of chordal ring architecture on the system performance and the response latency by using probability driven simulator.

• Journal of Chest Surgery
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• v.30 no.5
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• pp.533-536
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• 1997

We report a successful repair of severe traumatic tricuspid regurgitation by PTFE chordal replacement and ring annuloplasty. A 64-year-old man with multiple trauma was referred to our department because of cardiomegaly on chest roentgenogram. Echocardiography showed moderate amount of pericardial effusion and severe tricuspid regurgitation with rupture of anterior papillary muscle. But he experienced progressive dyspnea, and chest roentgenogram showed pro ressive cardiomegaly. He underwent operation 4 months after trauma. The nterior papillary muscle was reinserted, and the valve was repaired by PTFE chordal replacements and ring annuloplasty. Postoperatively, the patient's functional status was improved, and there was trivial tricuspid regurgitation on echocardiographic examination.

• Journal of Chest Surgery
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• v.14 no.1
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• pp.33-39
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• 1981

In the presence of severe non-calcific mitral regurgitation, a dilated mitral annulus, absence of severe subvalvular chordal thickening, and no major loss of leaflet substance, reconstructive surgery for mitral regurgitation is a reasonable approach. Between March, 1980 to November, 1980, 5 patients underwent mitral annuloplasty using Carpentier Ring for severe mitral regurgitation. All 5 cases were of rheumatic in origin. There were no ruptured chorda tendinae or ruptured papillary muscles except slight thickening of the leaflet. There was no operative or late death. As is Carpentier`s report, in patient with severe mitral regurgitation who meet above criteria, mitral annuloplasty using Carpentier Ring is preferable to valve replacement.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.70-81
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• 1988

From January 1962 to March 1987, 97 patients underwent operation for mitral valve disease. Of these patients, 61 [62.9%] required mitral valve replacement. Thirty-six patients [37.1%] had mitral valve repair. The mean age was 26.9*11.6 years [range 5 months to 48 years]. There were 32 [88.9%] cases of rheumatic valve disease, 4 [11.1%] cases of congenital mitral valve disease. Valve dysfunction was classified into three types: type I [normal leaflet motion], 6 patients; type II [prolapsed leaflet], 1 patient; type III [restricted leaflet motion], 29 patients. Twenty-nine patients [80.6%] had pure or predominant stenosis and 7[19.4%] had pure regurgitation. No patient was in NYHA functional class I. Three patients [16.7%] were in functional class II, 15[83.3%] were in functional class II. The techniques used included closed mitral commissurotomy [16 patients], open mitral commissurotomy [13 patients], localized Wooler type annuloplasty [4 patients], suture repair of leaflet defect [3 patients], chordal shortening [1 patient], Carpentier ring annuloplasty [1 patient], and fenestration of fused chordae [1 patient]. There were two perioperative deaths [5.6%], related to left ventricular failure and reoperation. The survivors were followed up for 94 patient-years [mean 4.68*5.54 years]. One late death [1.1*1.1% per patient-year] occurred and was valve related. Reoperation was required in 3 patients, of whom 2 were deaths. There was 1 case [1.1*1.1% per patient-year] of thromboembolism. No patient received anticoagulant after operation. At 10 year, 92*7.4% of the patients were still alive. The actuarial survival rate of patients free of valve-related complication was 79*6.4% at 6 years, 27*12.1% at 11 years. After surgery, 18 patients [88.9%] were in NYHA functional class I or II.

• Journal of Chest Surgery
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• v.31 no.3
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• pp.221-225
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• 1998

From February 1996 to May 1997, 18 patients underwent mitral valve repair for mitral regurgitation. There were 9 male and 9 female patients aged from 19 to 68 years(mean, 53). Thirteen patients were in New York Heart Association(NYHA) class III and IV. The cause of mitral regurgitation was degenerative in 12 patients, rheumatic in 5 patients and infective in 1 patient. Fifteen patients were in Carpentier's functional classification II, 2 patients in Carpentier's class III and 1 patient in Carpentier's class I. Surgical procedures included prosthetic ring annuloplasty(16 cases), rectangular resection of posterior leaflet(15 cases), chordal shortening(5 cases), triangular resection of anterior leaflet(2 cases), commissurotomy(2 cases), partial transposition of posterior leaflet(1 case). These procedures were combined in most patients. There was no operative death. These patients have been followed from 1 to 15 months, mean of 6.7 months. There was one late death resulted from low cardiac output following mitral valve replacement. The function of the repaired valve in other 17 patients has remained satisfactory during the observed interval. We consider that mitral valve repair is highly satisfactory in patients with mitral regurgitation.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.597-603
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• 2001

Background: The purpose of writing this article is to get better clinical results and further clinical improvement based on subject to 110 cases of cardiac surgery which were performed and clinically analyzed. Material and Method: Since January 1995, the patent ductus arteriosus surgery had started in our hospital. In February 1999, an open heart surgery had started and up to September 2000, total of 110 cases were performed as of double ligation of patent ductus arteriosus(10 cases) and open heart surgery(100 cases). Result: Among the patients, Korean-Chines was 74(67.3%) and Han-Chinese was 35(31.8%). Congenital heart disease was 95 cases and acquired valvular heart disease was 15 cases. 83 cases of acyanotic congenital heart disease consisted of ventricular septal defect(VSD) with associated anomaly(45 cases), atrial septal defect(ASD) with associated anomaly(20 cases), patent ductus arteriosus(PDA) with associated anomaly(11 cases), cogenital aortic stenosis(5 cases), double chamber right ventrical(1 case) and Ebstein's anomaly(1 case). Among the 12 cases of cyanotic congenital heart disease, 11 cases of tetralogy of Fallot underwent total correction. Among the 15 cases of acquired valvular heart disease, valvular replacement(7 cases), double valve replacement (3 cases), mitral valve replacement(3 cases) and aortic valve replacement(1 case) were performed. And 8 cases of valvuloplasty were performed by using of commissurotomy, chordal plasty, plasty of papillary muscle, ring type annuloplasty, repair of leaflet. Conclusion: on cogenital heart disease, short term results of surgery for acyanotic cogenital heart disease was good. Among the cyanotic congenital heart disease, tetralogy of Fallot showed a little difference of recovery according to the surgery method so that further follow up observation was needed for long term result. On acquired valvular heart disease, especially, in terms of short term result of valvuloplasty, was relatively good, but further follow up observation was also needed for long term result. There wasn's any operative mortality.