• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.45-48
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• 2001

It is a quite duality concerning to control the temperature of single crystalline growth as it does when we get most of heat treating products. It is also important factor to control the temperature when we make the $Al_2$O$_3$(single crystalline) used to artificial jewels. glass of watches, and heat resistant transparent g1asses. Thus, it is a major interest to get the proper temperature in accordance with the time process while we are making mixture of oxygen and hydrogen to have the right temperature. In this paper. we will study of electrical valve positioning system with DC-Motor for the gas mixture to improve the quality of products.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1694-1695
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• 2007

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(Al2O3) 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($Al_{2}O_{3}$) growth and we will design about realtime monitoring systems of the automatic gas contol DC- Motor for single crystal($Al_{2}O_{3}$) growth

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.4
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• pp.46-52
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• 2003

For position control of electro-hydraulic servo system, single rod cylinders and double rod cylinders are used. Single rod cylinders have simple structure for manufacturing but different volume ratio of two sides induce to non-linearity in process of then mathematical modeling. So only with conventional PID control method it is difficult to control single rod cylinders precisely. For mole precise position control of single rod cylinders, a controller which is inserted a velocity feedback PID controller and MRAC controller are proposed. With experiment control performances of three control methods are compared. In case of experiment, for external varying load to the system, a hydraulic cylinder and a pressure control valve are used. In conclusion a MRAC is considered a suitable control method for external varying load.

• Journal of ILASS-Korea
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• v.25 no.2
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• pp.45-50
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• 2020

Recently, global warming and environmental pollution are becoming more important, and fuel economy is becoming important. Each automobile company is actively developing various new technologies to increase fuel efficiency. CVVD(Continuously Variable Valve Duration) system means a device that continuously changes the rotational speed of the camshaft to change the valve duration according to the state of the engine. In this paper, VVT(Variable Valve Timing) and CVVD were applied to a single-cylinder diesel engine, and the characteristics of intake and exhaust flow rate and in-cylinder pressure characteristics were analyzed by numerical analysis. In order to analyze the effect of CVVD on the actual engine operation, the study was performed by setting the valve control and injection pressure as variables in two sections of the engine operating region. As a result, In the case of applying CVVD, the positive overlap with the exhaust valve is maintained, thus it is possible to secure the flow smoothness of air and increase the volumetric efficiency by improving the flow rate. The section 2 condition showed the highest peak pressure, but the pressure rise rate was similar to that of the VVT 20 and CVCD 20 conditions up to 40 bar due to the occurrence of ignition delay.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.130-136
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• 2001

This paper presents an of a brake pressure restriction valve to a motorcycle anti-lock brake system(ABS). In the conventional anti-lock brake system of automobiles, slip ratio as a control variable is actively controlled, which requires wheel speed sensors, ECU, and a pressure modulator. In the ABS valve that has been developed for use in motorcycles, however, the brake pressure that is close to the wheel locking pressure is preset by simple exercises and then the valve just allows to pass the wheel locking pressure and cutoff the remaining pressure. Simulation studies with a single wheel braking dynamics and lumped chassis model show that the pressure restriction valve has basic ABS functions as well as some robustness properties for the uncertain load and road conditions as well as various initial braking speeds. Field tests also show that the pressure restriction valve avoids the wheel locking effectively.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.80-86
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• 1996

In order to decrease fuel comsumption rate and emissions, lean burn engine which has equipped swirl control valve, is investigated experimentally on the test bench. Single cylinder engine was used to test the combustion and emission performance with 4 kinds of swirl valve. Decrease in the carbon monoxide, hyerocarbon and specific fuel consumption was shown at the lean condition, which means that a good choice of swirl valve on the given intake port geometry can be used to increase the combustion efficiency and lean limit.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1225-1230
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• 2007

The turnover-type sluice gate is typically actuated by the hydrauic system. The hydraulic system may be a open circuit type or a closed circuit type. The open circuit type hydraulic system is composed of a uni-directional pump, a directional control valve, pilot operated check valves, flow control valves, single-rod cylinders. The closed circuit type hydraulic system is composed of a bi-directional pump, pilot operated check valves, check valves, a counter balance valve, single-rod cylinders. The energy efficiencies of two hydraulic systems for the turnover-type sluice gate are compared here.

• 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.

• The Korean Journal of Emergency Medical Services
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• v.23 no.3
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• pp.29-40
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• 2019

Purpose: This study was conducted to identify the effects of educational intervention on pre-test and post-test tidal volume, endotracheal peak pressure, and ventilation interval measurements during single-rescuer respiratory-assistant therapy by paramedic students. Methods: The present study, with a quasi-experimental design, included a pre-test and post-test nonequivalent control group. A total of 62 paramedic students (31, experimental group; 31, control group) participated in this study. The intervention lasted 80 minutes. Data were collected from each student before the intervention and two weeks after the intervention, between September 3 and 21, 2018. The collected data were analyzed using IBM SPSS Statistics for Windows, Version 25.0. Results: Tidal volume (p<.001) and endotracheal peak pressure (p=.002) measurements after the intervention were significantly different between the two groups. Analysis of covariance was used to control the variance (the pretest value of endotracheal peak pressure) in order to identify the effect of the intervention in the two groups. Endotracheal peak pressure was not significantly different between the two groups. Conclusion: Education and training of paramedic students in emergency medical services on single-rescuer respiratory-assistant therapy is necessary for the emergency care of patients with respiratory arrest.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.110-115
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• 2015

In this paper it is proposed to solve the problem of particulate matter reducing apparatus of the current DPF. One exhaust gas passage 2-way controlled to purify the exhaust gas generated during combustion efficiently. Through the control of the rotary valve within a single device, it is possible to prevent the exhaust pressure increases due to particulate matter accumulate inside the developing DPF. Develop DPF device capable of inducing a high efficiency of the output in order to improve the problem of reducing the engine output and fuel efficiency.