• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.691-696
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• 2004

Recently, it is required that the automotive air conditioning system must keep the cabin temperature comfortable in spite of engine speed, and Improve the fuel consumption during all the seasons. To satisfy these requirements, the variable displacement swash plate type compressor with control pressure valve is developed. In this study, the effects of two type valves, suction pressure control valve and differential pressure control valve, on the performance of swash plate type compressor has been investigated experimentally.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.469-473
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• 2005

Capacities of a tandom-type air-conditioner may be modulated by turning on/off multiple compressors and adjusting positions of a electronic expansion valve. In this study. control algorithms for compressors and a electronic expansion valve were developed by using fuzzy’ logics. There algorithms were implemented in a test lab and proved to be effective for the control of indoor air temperature and superheat temperature.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.675-680
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• 2006

Capacities of a tandem-type air-conditioner may be modulated by turning on and off of multiple compressors, and adjusting the position of a electronic expansion valve. In this study, control algorithms for compressors and a electronic expansion valve were developed by using fuzzy logics. The pressure control algorithm was also developed for the safe operation of compressors. There algorithms were implemented in a test lab and proved to be effective for the control of indoor air temperature and superheat temperature,

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.67-73
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• 2013

This experimental work described the effect of flow control valve type on the performance of wobble plate type fuel pump for the stable DME fuel supply. In order to study this, different four types of flow control valves (ITV, SCV, IMV and MPROP) were installed on the wobble plate fuel pump, and fuel flow rate, torque, and temperature variation of pump were investigated under various operating conditions by using pump performance test system. It was revealed that wobble plate type fuel pump worked well with ITV and SCV control valve, and the flow rate and torque of fuel pump was in proportion to the value of valve open duty. The maximum flow rate and torque of fuel pump were achieved around the 50% duty of control valve. Temperature variation at all pump measuring points were under $60^{\circ}C$ which is acceptable.

• Solar Energy
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• v.16 no.2
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• pp.97-112
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• 1996

The purpose of research is to complement the circulating pump of gas boiler for the domestic and to develop a pump housing with internal three way valve: Housing and three way valve have been apart in the existing pump system. Based on the experimental result on can-typed circulating pump with existing housing, a new housing with internal three way valve was designed and manufactured. The performance of can-typed circulating pump with the new housing, and the performance of circulating pump of boiler system were tested. As a result ot the test, the new housing with internal three way valve has been excellent in respect of pump performance, weight and manufacturing cost. So It is expected to have an effect of import substitution.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.951-955
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• 2004

Piezoelectric(PZT) actuator can substitute for solenoid which is used in fluid control field because it has faster response times and no possibility of explosion. Besides, it is available in a high temperature and it has low energy consumption. In this study, pneumatic micro valve, bimorph type PZT actuator using the softner type PZT, carbon plate as a shim and its controller circuit were suggested and investigated. Performance tests and characteristics analysis, such as displacement, force, hysteresis and frequency properties, were carried out. The displacement of the actuator measured at the end point was 63 ${\mu}m$., force of the actuator was 0.052 N and maximum operating frequency was 15Hz. Also, characteristics of the micro valve with PZT actuator were evaluated in a testing system. The results show that the suggested PZT actuator is suitable for micro valve.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.614-619
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• 1984

Atrioventricular canal is divided into incomplete, intermediate and complete types. In ostium primum ASD [incomplete type] mitral valve cleft is almost always present, but ostium primum ASD with tricuspid valve cleft is a rare congenital anomaly. The patient was a 7 year old female whose complains were palpitation, exertional dyspnea and growth retardation. The chest films showed moderate cardiomegaly [C-T ratio, 61%]. EKG, Echocardiography, cardiac catheterization and left ventriculography were performed. Open heart surgery was done under the impression of incomplete atrioventricular canal. At the time of operation, ostium primum ASD [2x2.5 cm in diameter], secundum type ASD [lxl.5 cm in diameter] and cleft in the septal leaflet of the tricuspid valve were noted. But mitral valve was normal without cleft and VSD was not noted. Each anomalous portion was repaired. The patient made an uneventful recovery and we report this case, review and discuss the literatures.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.456-459
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• 2011

The Dual-type Solenoid Valve was developed for a domestic production of a fuel-supply valve on the satellite attitude control thruster system. The satellite valve using a hydrazine as a fuel must fulfill the cycle life, shock, vibration and the environment of an extremely low temperature In addition to the basic performance of the response time, mass flow and leakage etc.. in this paper, the design, production and performance experiment using the nitrogen pneumatic equipment were conducted.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.745-749
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• 2002

This paper is on the study of flow force compensating method of spool type valve. A simple flow force compensating method using stepped spool is presented in this paper. It is easy to manufacture stepped spool in the presented method because the shape of it is simple. The method has the merit that the size of valve need not be increased. Actuating force required for driving means of spool can be decreased by the compensation of flow force. The effect of presented method is predicted through CFD analysis. The prototypes of flow force compensating Direct Drive Servo-Valve where the result of CFD analysis is reflected are manufactured, and the measurement of flow force is carried out. It is known from the measurement that the effect of flow force compensation is very similar to from CFD analysis.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.225-230
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• 2002

Machine of textiles let off is equipment supplying constantly fabrics. Nowdays, as it is replaced band - brake type with hydraulic motor driven type, we looked into characteristic of hydraulic solenoid pilot direction valve(SPDV) for controlling acceleration performance of hydraulic motor. This study deals with controlling the initial speed of textiles let off machine. Finally, to control the initial speed of hydraulic motor, we controlled the adjustment screw of SPDV by a hand. Test which was carried out in the laboratory shows that initial speed of textiles let off could be improved by controlling adjustment screw of SPDV. Also, the results of experiment work were compared with dynamic characteristic of other on/off solenoid direction valve(SDV).