• Journal of Chest Surgery
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• v.47 no.3
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• pp.283-286
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• 2014

A 61-year-old man was diagnosed with aortic stenoinsufficiency with periannular abscess, which involved the aortic root of noncoronary sinus (NCS) that invaded down to the central fibrous body, whole membranous septum, mitral valve (MV), and tricuspid valve (TV). The open complete debridement was executed from the aortic annulus at NCS down to the central fibrous body and annulus of the MV and the TV, followed by the left ventricular outflow tract reconstruction with implantation of a mechanical aortic valve by using a leaflet of the half-folded elliptical bovine pericardial patch. Another leaflet of this patch was used for the repair of the right atrial wall with a defect and the TV.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.1
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• pp.29-35
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• 2009

Butterfly valve is a kind of rotational valve which opens and closes the flow of fluid on rotating the disk 90 degrees in the valve body. In this paper, butterfly valve design safety evaluation which is based on the international valve specifications is investigated. Both body and disk of the butterfly valve are considered under the normal and pressurized operating conditions. A finite element analysis is carried out to compute the distribution of the displacement, stress and safety factor by using ANSYS. On the basis of calculated design safety we offer the design modification and compare with them.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.144-152
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• 2018

The cleanability of machine parts is becoming increasingly important in the industrial field. In particular, cleanability is the most important factor in hydraulic products. The burr and chips are dominant factors of cleanability. If the burrs are not removed completely before the beginning of the machining stage, this will cause many problems, such as scratches and operation failure. Due to the complexity of the valve body itself, it is very difficult to use common deburring tools. In this study, a brush-like deburring tool was suggested and verified as a proper tool for removing the burrs and forming a proper edge shape through a real experiment. Various kinds of brush materials and process conditions were tested for proper deburring of the valve body. It was shown that the suggested method was successful for valve body deburring.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.167-177
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• 2003

In this study, a mathematical nonlinear dynamic model is introduced to predict the damping force of automotive shock absorber. And 11 design parameters were proposed for the sensitivity analysis of damping force. Design parameters consist of 5 piston valve design parameters, 5 body valve design parameters and 1 initial pressure of reservoir chamber air. All of these design parameters are main design parameters of shock absorber in the procedure of shock absorber design. The simulation results of this paper offer qualitative information of damping force variation according to variation of design parameters. Therefore, simulation results of this paper can be usefully use in the design procedure of shock absorber

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.79-84
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• 2011

In general, a valve body of the automatic transmission(AT) is controlled by the clutch, the brake and lubricating oil flow in a hydraulic system and lubricant flow for each valve can be adjusted independently. To increase the lifetime of AT, the lubrication flow rate in a valve body for a 6 speed AT based parallel hybrid electric vehicle must be provided with proper oil distribution and control. In this study, we carried out several experiments without the inner parts of AT and with a AT assembly. The variation of the flow rate on oil temperature and pressure between an oil supply port and the outlets of the lubrication port was evaluated and analyzed. In the case of AT without the inner parts, it was evident that as the oil required for an operation of the clutch and brake was discharged from the outlet port, the flow rate from each lubrication port is decreased. However, the flow rate of the AT assembly was slightly increased. In addition, the lubrication flow rate was increased with increasing the oil temperature, and also it was reduced with increasing the oil pressure. Details of the resulting data are discussed.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.80-84
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• 2015

In this paper, the valves for a LPG gas cylinder have been investigated on the body height and weight by comparing design data between typical automatic shut-off vertical and newly developed horizontal valves. The height of an automatic shut-off horizontal valve is radically reduced by 41~42% compared with that of a typical automatic shut-off vertical valve. And, the body weight of a horizontal valve is also reduced by 29~40% compared with that of a vertical shut-off valve. This result is just achieved by a structural design modification from typical vertical valve to horizontal arrangement of various valve components.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.104-111
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• 2003

The performance of shock absorber is directly related to the car behaviour and performance, both for handling and comfort. In this study, a mathematical nonlinear dynamic model and computational method are introduced to study the flow and performance of shock absorber. The flow characteristics of components(piston and body valve) are investigated and applied to dynamic modeling of shock absorber to predict the damping force. The simulation results agree with the test data well. The shock absorber model proposed in this paper is applicable as a part of a full vehicle suspension simulation.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.269-275
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• 2018

Nasal valve compromise (NVC) is a distinct cause of symptomatic nasal obstruction, yet there are several ambiguities surrounding the diagnosis and management of this disease. Understanding of nasal valve anatomy with critical assessment of the site of obstruction is essential to effective nasal valve management. Technique selection should be individualized to the type of valve dysfunction. This case report presents a 56 year old man with nasal valve dysfunction due to narrow middle vault, concave lower lateral cartilage and swollen septal body which was diagnosed by various techniques including navigation system and treated by spreader graft, alar batten graft and reduction of septal body.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.85-93
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• 2009

In this paper, the geometric design for the body of a 3"-PFA-lined plug valve is concerned, and body model which has less deformed PFA-resin after infection molding process is proposed. A CAE software is used to simulate the deformation due to heat in cooling. To reduce the deformation, some small shapes are added to PFA-resin surfaces related on wall of the valve housing. And thermal stress simulation with FEM methodology is followed after that. Also, the 3D-CAD package is used during the design processes. In this study, I tried to present the possibility to use the FEM analysis in the solid modeling process. So, the design engineer will be able to use analysis package effectively on his job within the limited range.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1459-1464
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• 1996

The most important parameter for hydraulic active suspension system is to sustain desirable vehicle maneuvering stability and ride comfort without increasing consumption power. The performance of hydraulic active suspension system depends on damping force of body damping valve and piston damping valve. Hydraulic actuator design and damping valve parameter selection are essential and basic procedure to design hydraulic active suspension system. This paper is on computer simulation with use of mathematical model that was delivered from dynamic characteristic of hydraulic actuator, as know basic damping characteristics of hydraulic active suspension system. The aim of this paper is to select the system parameter that affect mainly hydraulic active suspension, and identify the validity on the system parameter selection.