• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.491-492
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• 2008

인공위성에 탑재되는 S/W는 위성 내의 다양한 장치들과 유기적으로 통신하며 위성의 동작을 제어하고 임무를 수행한다. 따라서 이들 장치들과의 상호 작용이 충분히 테스트되어야 하나, S/W 개발 과정에서 해당 장치들과 직접 연동되어 개발하기 어려운 경우가 대부분이다. 이에 위성에 탑재되는 다른 장치 및 탑재체의 기능과 역할을 모사할 수 있는 시뮬레이터가 필요성이 대두된다. 본 연구에서는 Java를 이용한 시뮬레이터 개발 방안에 대하여 소개한다.

• Journal of the Korean Solar Energy Society
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• v.37 no.2
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• pp.13-22
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• 2017

Two-step water splitting thermochemical cycle with $CeO_2/ZrO_2$ foam device was investigated by using a solar simulator composed of 2.5 kW Xe-Arc lamp and mirror reflector. The hydrogen production of $CeO_2/ZrO_2$ foam device depending on heat recovery of Thermal-Reduction step and Water-Decomposition step was analyzed, and the hydrogen production of $CeO_2/ZrO_2$ and $NiFe_2O_4/ZrO_2$ foam devices was compared. Resultantly, the quantity of hydrogen generation increased by 52.02% when the carrier gas of Thermal-Reduction step is preheated to $200^{\circ}C$ and, when the $N_2/steam$ is preheated to $200^{\circ}C$ in the Water-Decomposition step, the quantity of hydrogen generation increased by 35.85%. Therefore, it is important to retrieve the heat from the highly heated gases discharged from each of the reaction spaces in order to increase the reaction temperature of each of the stages and thereby increasing the quantity of hydrogen generated through this.

• Journal of the Korean Solar Energy Society
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• v.34 no.6
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• pp.11-18
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• 2014

Two-step water splitting thermochemical cycle with $CeO_2$ foam device was investigated by using a solar simulator composed of 2.5 kW Xe-Arc lamp and mirror reflector. The hydrogen production of $CeO_2$ foam device depending on reaction temperature of Thermal-Reduction step and Water-Decomposition step was analyzed, and the hydrogen production of $CeO_2$ and $NiFe_2O_4/ZrO_2$ foam devices was compared. As a result, the amount of reduced $CeO_2$ considerably varies according to the reaction temperature of Thermal-Reduction step. and hydrogen production was not much when the amount of reduced $CeO_2$ decreased even if the reaction temperature of Water-Decomposition step was high. Therefore, it is very important to keep the reaction temperature of Thermal-Reduction step high in two-step thermochemical cycle with $CeO_2$.

• Journal of the Korean Solar Energy Society
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• v.37 no.5
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• pp.27-37
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• 2017

In this study, an artificial solar simulator composed of a 2.5 kW Xe-Arc lamp and mirror reflector was used to carry out the solar thermal two step thermochemical water decomposition cycle which can produce high efficiency continuous hydrogen production. Through various operating conditions, the change of hydrogen production due to the possibility of a dual-zone reactor and heat recovery were experimentally analyzed. Based on the reaction temperature of Thermal-Reduction step and Water-Decomposition step at $1,400^{\circ}C$ and $1,000^{\circ}C$ respectively, the hydrogen production decreased by 23.2% under the power off condition, and as a result of experiments using heat recovery technology, the hydrogen production increased by 33.8%. Therefore, when a thermochemical two-step water decomposition cycle is conducted using a dual-zone reactor with heat recovery, it is expected that the cycle can be operated twice over a certain period of time and the hydrogen production amount is increased by at least 53.5% compared to a single reactor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.915-918
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• 2016

Virtual testing devices are required due to rapid changes in the health care industry and the increase of the medical or nursing workforce. The importance of devices such as the simulator, blood vessels, and lab equipment for modeling blood flow to the heart is increasing too. In this study, we made heart pump by using a step motor and developed device which simulates arterial, venous blood pressure, and blood flow. We finally evaluated the function of proposed device. The proposed system is composed of the pump for simulating, the valve device to describe the resistance of the artery and vein, and a reducing device showing the characteristics of the venous system. We used BOXER pump for heart simulator and silicon tube for arterial and venous vessels, and designed a reducing device. We also used the pressure sensor to measure arterial blood pressure. For the evaluation of the proposed system, we selected a range of 50~100mmHg of the blood circuit 60 per minute and then compared the blood pressure of a person and the measured blood pressure.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.209-211
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• 2007

본 논문에서는 회생에너지 저장시스템의 충/방전 제어를 위한 가선전압 모의 장치를 제안한다. 제안된 시뮬레이터는 실측된 가선전압 데이터를 입력으로 받아 실측 가선전압과 동일한 전압패턴으로 모사한다. 이러한 전압패턴은 회생에너지가 포함된 가선전압이며 이를 토대로 에너지 저장시스템에 연계시켜 충/방전 제어를 좀 더 효율적으로 수행할 수 있다. 제안된 시뮬레이터는 AC/DC 컨버터 타입으로 시뮬레이션과 실험을 통해 제안된 시스템의 타당성을 확인하였다.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.406-408
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• 2007

현재 국가물류 수송의 경쟁력 향상과 증가되는 교통수요에 부응하기 위해 경부 고속철도의 건설 등 철도의 고속화와 수송량 증대에 많은 관심과 투자가 이루어지고 있지만, 점점 상승하는 유가 에너지 비용에 대한 문제가 발생하고 있어 전기 철도차량의 개발이 시급하다. 본 논문은 Simplorer 프로그램을 이용하여 열차 추진 장치에 관한 연구와 추후 열차 회생 에너지에 관한 연구를 하기 위해 추진 장치를 M-G set으로 구성 하였고 모터는 SVM(Space Vector PWM)방식으로, 제너레이터는 DTC(Direct Torque Control) 방식으로 제어하였다.

• Journal of Biomedical Engineering Research
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• v.29 no.4
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• pp.323-328
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• 2008

A patient with respiratory disorders such as a sleep apnea is increasing as the obese patient increase on the modern society. Positive Airway Pressure (PAP) devices are used in curing patient with respiratory disorders and turn out to be efficacious for patients of 75%. However, these devices are required for evaluating their performance to improve their performance by the mechanical breathing simulator. Recently, the mechanical breathing simulator was studied by the real time feedback control. However, the mechanical breathing simulator by an open loop control was specially required in order to analyze the effect of flow rate and pressure after operating the breathing auxiliary devices. Therefore the aims of this study were to make the mechanical breathing simulator by a piston motion and a valve function from the characteristic test of valve and motor, and to duplicate the flow rate and pressure profiles of some breathing patterns: normal and three disorder patterns. The mechanical simulator is composed cylinder, valve, ball screw and the motor. Also, the characteristic test of the motor and the valve were accomplished in order to define the relationship between the characteristics of simulator and the breathing profiles. Then, the flow rate and pressure profile of human breathing patterns were duplicated by the control of motor and valve. The result showed that the simulator reasonably duplicated the characteristics of human patterns: normal, obstructive sleep apnea (OSA), mild hypopnea with snore and mouth expiration patterns. However, we need to improve this simulator in detail and to validate this method for other patterns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.116-122
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• 2010

This paper describes the up-grade of the turbine governor for steam turbine due to its poor operation from long time use. The analog type governor of the unit 1 in Kori nuclear power plant in Korea was removed and the new digital type turbine governor was developed and installed. The procedure for the actual application, site adaptability test using dynamic simulator and the result of actual operation are described here. And the program for nuclear steam turbine is suggested here.

• Journal of the Korean Society of Visualization
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• v.11 no.2
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• pp.34-40
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• 2013

A flow visualization near submerged nozzle of solid rocket motor was conducted by experiments. A numerical simulation was also performed to reveal detailed phenomena. Radial cold flow simulating hot gas was introduced by a porous grain model which was manufactured by perforated steel plates. The grain model was mounted in high-pressure chamber which has quartz glass at the top of the grain model. From the high-speed images, a rotating vortex was observed and the two type of counter-rotating momentums were generated in numerical results. The rotating momentum was generated at the fin-slot grain because of unbalance between high-velocity flow from slots and low-velocity flow from fin-bases. As a result, roll torques can be produced by the rotating vortex tube.