• Journal of ILASS-Korea
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• v.27 no.3
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• pp.117-125
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• 2022

This study examines whether engine fuel efficiency is improved by optimization of the exhaust valve timing in a state where the intake valve timing has been optimized in a small turbo gasoline engine that has intake cams and exhaust cams with fixed valve opening periods. When the exhaust valve is opened late, the expansion stroke is longer, and the efficiency can be improved. A 2-cylinder turbo gasoline engine with 0.8 liters of displacement and an MPI (Multi Point Injection) fuel system was used. The engine was operated at 1,500 and 3,000 rpm, and the load conditions included a partial load of 50 N·m and a high load of 70 N·m. Data was recorded as the exhaust valve timing was controlled, and this was used to calculate the efficiency of combustion using a heat release, the fuel conversion efficiency, and the pumping loss. Results and the hydrocarbon concentrations in the exhaust gas were compared for each condition. Experiment results confirmed that additional fuel efficiency improvements are possible through exhaust valve timing control at 1,500 rpm and 50 N·m. However, in other operating conditions, fuel efficiency improvements could not be obtained through exhaust valve timing control because cases where the pumping loss and fuel/air mixture slip increased when the exhaust valve timing changed and the fuel efficiency declined.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.37-42
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• 2016

The purpose of this paper is to study for the emission gas control of passenger car. The first example, the PCSV never open when operating condition, but it opened by causing malfunction because of trouble. As a result, the purge gas entered into surge tank, a mount of fuel was displayed with excessive supply on tester. Therefore, it certified the bad-condition of the engine when idling by decreasing of fuel injection quantity from engine ECU. The second example, the hose activating a EGR valve didn't supply the vacuum pressure because of assembling the other part. Thus, it knew the bad-condition of engine that the EGR valve would not work normally by leaking with the other port. The third example, as the rear oxygen sensor of two sensor were fault-installing by changing the sensor of other a car it could not detect of oxygen quantity. Finally, it found the phenomenon of abruptly decreasing vehicle speed when braking a car. Therefore, the system including with emission control has to drastically manage by maximizing condition to role decreasing the emission gas.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.917-920
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• 2006

It is possible to make a practical application for many services by using Home Networking. It's brings much improve the quality of our life. Remote control communication should be made by Home Network but present networks are generally using wireless Internet. But, this method don't use exist home and not install wireless internet. Because It need to many devices. Therefore, in this paper we implement gas valve remote control system using RPM(Radio Packet Modem). We can easily installing systems and operating. This system provide different solution for Home networking.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.229-230
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• 2007

It is possible to make a practical application for many services by using Home Networking. It's brings much improve the quality of our life. Remote control communication should be made by Home Network but present networks are generally using wireless Internet. But, this method don't use exist home and not install wireless internet. Because It need to many devices. Therefore, in this paper we implement gas valve remote control system using RPM(Radio Packet Modem). We can easily installing systems and operating. This system provide different solution for Home networking.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2796-2798
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• 2000

It is a quite quality concerning to control temperature of single crystalline growth as it does when you get most of heat treating products. It is also important factor to control temperature when you make the $Al_{2}O_3$(single crystalline) used to artificial jewels. glass of watches. heat resistant transparent glasses. Thus. it is a major interest to get the proper temperature in accordance with the time process while you are making mixture of oxygen and hydrogen to have the right temperature. In this paper. we will study of electrical valve positioning system for the gas mixture to improve the quality of products.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2489-2491
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• 2004

DC-Motor is needed more and more sophisticated control to follow the highest precision of industrial automation and used in a number of control equipment or industrial fields. It is also useful to control single crystal($A1_2O_3$) growth. It is possible to procure a quality crystal utilizing a DC-Motor, if you mix Hydrogen and Oxygen gas properly and keep proper temperature in accordance with time process. In this paper, we will study about electrical valve positioning system for the gas mixture to improve the quality of single crystal($A1_2O_3$) growth and we will design about realtime monitoring systems of the automatic gas control DC- Motor for single crystal($A1_2O_3$) growth.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.237.1-237
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• 2001

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.1-9
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• 2010

Fuel shutoff valve of a gas generator controls propellant mass flowrate of a rocket engine, by using pilot pressure and spring force. The developing fuel shutoff valve can be self sustained even though pilot pressure is removed in an actuator. Therefore, it is necessary to analyze the characteristics of the forces with respect to the opening and closing of the valve in order to evaluate its performance. In light of this, the valve has been designed to adjust the control pressure for the opening of the poppet and to determine the working fluid pressure at which the valve starts to close. This paper also has been designed dynamic model using the AMESim and predicted flow coefficient of the valve by Fluent CFD analysis. Various results from the prediction and the analysis have been compared with experiments. Finally, dynamic characteristics of the valve have been verified with experimental results.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.6
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• pp.48-55
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• 2009

The purpose of using Gas Generator Oxidizer On/Off Valve(GOV) is to control opening and closing of oxidizer mass flow. This paper describes analytical results of flow and structural properties for four different GOV models, using commercial software such as Fluent(Ver. 6.3.26) and NASTRAN(2005 r.2), PATRAN(2005 r.2). Analytical results show that GOVs could generate 2.3~3.8 kg/s of oxidizer mass flow rate and come up with 1.09~1.42 of safety factor.

• Journal of the Korean Institute of Gas
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• v.15 no.6
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• pp.28-33
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• 2011

The purpose of this paper analyzes and studies to improve the failure cases on the computer that one of electronic control elements for engine in liquified petroleum gas vehicle. The first case, it certified the non-starting phenomenon of engine that it's electronic control unit didn't control the fuel for idle speed actuator because of no given action signal in slow-cut solenoid valve. The second case, it knew the bad condition phenomenon of engine and back-fire by the wire melting of ignition coil and firing of transistor being inside ECU. The third case, it certified the action stoping phenomenon of engine and malfunctioning signal for engine ECU because of leakage of current and an excess current by moisture inflowing inside ECU curcuit plate. Therefore, it is thought that will elevate the durability and reliability of engine computer throughout procure of quality.