• Journal of Chest Surgery
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• v.24 no.9
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• pp.870-880
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• 1991

One hundred eleven cases of open heart surgery had been performed at the department of thoracic and cardiovascular surgery in College of Medicine Hallym Univ. from November 28, 1984 to August, 1991. There were 68 cases of congenital heart disease and 43 cases of acquired heart disease. Among the 68 cases of congenital heart diseases, 65 cases of acyanotic group and 3 cases of cyanotic group were noted. The majority of acquired heart diseases were valvular heart disease. The congenital heart disease consisted of 33 ASD, 27 VSD, 6 PS, 3 TOF. The sex ratio of congenital and acquired heart diseases was represented as 1.4: 1 and 1; 1.4 respectively. The age distribution of congenital heart diseases ranged from 11 months to 50 years old and that of acquired heart diseases from 15 to 61 years old. The overall operation mortality was 1 case[0.9%].

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.43-50
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• 2000

In the first-order shear deformation laminated beam theory (FSDT), the Kirchhoff hypothesis is relaxed such that the transverse normals do not remain perpendicular to the midsurface after deformation. Bending behavior of laminated composite thin-walled beams with singly- and doubly-symmetric open sections under uniformly distributed and concentrated loads is analyzed by the Timoshenko-type thin-walled beam theory. A closed-form expression for the shear correction factor of I-shaped composite laminated section is obtained. Numerical examples are presented to compare present analytical solutions by FSDT with the finite element solutions obtained by using three dimensional model. The effects of lamination of scheme and length-to-height ratio on the shear deformation of laminated composite beams with various boundary conditions are studied.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.194-196
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• 2006

This paper deals with design of a small-scaled permanent magnet generator (PMG) for wind power applications. First, this paper determines rated power and rated speed of the PMG from measured characteristics of wind turbines. Second, we derive analytical solutions for the open-circuit field in order to determine optimum magnet thickness and pole pitch/arc ratio. Third, on the basis of open circuit field solutions, stator magnetic circuit is designed. And then, a diameter of stator coil which agree with a required current density is calculated, and its turns are determined from the area of slot. Finally, finite element (FE) method is employed for validity of the designed PMG and, the back-emf measurements are also given to confirm the design.

• Water for future
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• v.18 no.4
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• pp.361-367
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• 1985

The variation of water surface profile due to the constriction of flow section in open channel was analysed by numerical scheme. Findings are that the variations of water surface are mainly dependent on the constriction ratio and Froude number of uniform flow, and the magnitudes of backwater obtained from the flow profiles agrees fairly well with the experiments by Skogerboe. This implies that the backwater can be predicted by numerical technique.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.480-485
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• 2004

The applications of composite materials have increased over the past few decades in a variety of structures that require high ratio of stiffness and strength to weight ratios. Recently the thick open section composite beams are used extensively as load carrying members and stiffeners of structural elements. However, most of studies on thick composite beams are limited only to closed section beams. In this study, an open cross-section thick-walled composite beam model which includes coupled stiffness, transverse shear, and warping effects is suggested and the deflections associated with the thick-walled composite beams and thin-walled composite beams are obtained and compared with the finite element analysis results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.6
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• pp.1762-1772
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• 1996

The main objective of this study is to develop a gripper mechanixm that can be employed for assembly and removal tasks of a nozzle-dam of steam genetator in the process of the nuclear reactor maintenances. Brief description of the open-close thpe gripper mechanism, its position analysis, and its kinematic analysis are given. The optimal design of the gripper mechanism with and without slipping on its two gipping surfaces is considered. As an optimal design index, the ratio of the actuator force of prismatic cylinder to gripping load is proposed. Then, based on this index the oiptimal design is carried out to identify values of optimal design parameters for the gripper dechanism.

• Journal of Chest Surgery
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• v.24 no.6
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• pp.555-559
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• 1991

Post-pneumonectomy empyema thoracis is an uncommon, but very serious problem. Early diagnosis & adequate drainage followed by thoracoplasty and or myoplasty are very important principles for the management of the empyema thoracis & will enable patient to recover from the toxic effects. During the period of January, 1985 to December, 1990, 13 patients with post-pneumonectomy empyema thoracis were treated in the department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine. There were 10 males % 3 females ranging from 31 years to 79 years of age. The occurrence ratio of left to right side was 8: 5. The underlying pathologic lesions of empyema thoracis were pulmonary tuberculosis[7], lung ca. [2] pneumothorax[2], lung abscess[1] pneumonia[1]. We treatment procedure for post-pneumonectomy empyema thoracis were open window thoracostomy in 10 cases, Clagett procedures in 2 cases, one thoracoplasty, and two cases of Clagett procedures followed by open window thoracostomy in one cases.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.498-505
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• 1987

From June 1984 to Aug. 1986, 90 cases of open heart surgery were performed at the department of cardiothoracic surgery of Kosin Medical College. There were 63 cases of congenital cardiac anomalies and 27 cases of acquired heart diseases. The sex ratio of congenital and acquired heart diseases were represented as 1.4:1 and 1:1.5 respectively. The age distribution was ranged from 7/12 to 56 years old. Among the 63 congenital cardiac anomalies, 49 cases of acyanotic group and 14 cases of cyanotic group were noted. In 49 cases of acyanotic group, 32 VSD, 15 ASD, 1 PS, and 1 RCA-LV fistula were noticed. In 14 cases of cyanotic group, 7 TOF, 1 TOF (Dextrosardia) combined with IVC interruption, 1 Triology of Fallot, 2 Pentalogy of Fallot. 1 DORV, 1 TA with PDA, VSD, ASD and Left SVC and 1 TAPVC were included. Of the 27 acquired heart diseases, 13 mitral, 3 aortic , 6 bival, 3 triplevalvular diseases and 2 LA myxomas were noted. Overall mortality were 11 cases, which included 2 cases of acyanotic heart diseases, 6 cases of cyanotic heart diseases and 3 cases of acquired hear diseases.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.239-243
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• 2005

Fully three-dimensional Large Eddy Simulation calculations of the flow past 2D cavity are conducted to study the purging of neutrally buoyant or dense miscible contaminants introduced instantaneously inside the cavity. The length to depth ratio(L/D) is 2 and Reynolds number based on the depth is 3,360. Fully developed turbulent inflow are fed at the inlet from precursor simulation of channel flow. Mean flow pattern and unsteady features are investigated based on the experimental data of Pereira and Sousa. From the study of mass exchange processes, it is found that the mechanism of removal of the contaminant is very different between the non-buoyant and buoyant cases. In the buoyant case, internal wave motion which interacts with a strong cavity vortex is dominant in the ejection mechanism of the contaminants.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.780-785
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• 1984

We had studied 20 cases of VSD patients whose murmur was sustained after open heart surgery from 1977 to 1984. The postoperative cardiac catheterization was performed on post-op. 20th day. Their ages ranged from 5 to 25 years old. Among them, 4 patients had significant residual shunt which required reoperation. [1 patient; re-op, 3 patient; refused]. Sex ratio was 13:7 in male and female. Associated anomalies were PDA, ASD, Pulmonary stenosis, Mitral insufficiency. Except 1 case, all of them was Kirklin type II VSD. Postoperative complications were I RBBB, residual shunt, cardiac tamponade due to bleeding, wound infection. Preoperative pulmonary artery systolic pressure was highly related to residual shunt in our study. Postoperative LVEDV returned to normal range on the 3rd week.