• 한국기계가공학회지
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• 제3권1호
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• pp.79-83
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• 2004

This study was how to control the mass flow controller in gas supplying system. The flow controller consists of piezoelectric material and sensor with heating wire. It is difficult to obtain accurate model, because MFC was composed of many parts, and the relationship between input and output of controller is nonlinear. The model for control was obtained by time constant and DC gain Based on this model, PID controller was applied to flow controller using DSP board. Also, the results were compared to controller using system identification.

• 한국추진공학회지
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• 제21권5호
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• pp.54-60
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• 2017

연소불안정 연구의 일환인 화염전달함수에서 나타나는 gain의 특성을 파악하기 위하여 비연소상태에서의 전달함수를 도입하여 화염전달함수에서의 특성과 비연소전달함수의 특성에 대한 원인을 파악하고자 하였다. 비연소 전달함수를 획득하기 위하여 질소와 이산화탄소를 활용하였으며, 입력값과 출력값을 계측하기 위하여 열선풍속계를 이용하였다. 비연소 전달함수에서의 gain과 주파수의 peak는 비활성기체의 밀도와 유량에 대하여 영향을 받는 것을 확인하였다. 또한 연료공급라인에서의 음향학적 공진주파수가 peak 주파수에 영향을 주는 것을 확인하였다.

• International Journal of Fluid Machinery and Systems
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• 제5권3호
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• pp.126-133
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• 2012

The transfer matrix and unsteady cavitation characteristics, cavitation compliance and mass flow gain factor, of cavitating inducer were evaluated by CFD using commercial software. Quasi-steady values of cavitation compliance and mass flow gain factor were obtained first by using steady calculations at various flow rate and inlet cavitation number. Then unsteady calculations were made to determine the transfer matrix and the cavitation characteristics. The results are compared with experiments to show the validity of calculations.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 추계학술대회
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• pp.153-156
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• 1994

An in vitro steady flow experiment was performed in order to test the accuracy of velocity measurement obtained through a pulsed Doppler echocardiography. A flow phantom was designed for the use in a wide velocity range at a given flow rate. The results showed that the pulsed Doppler velocity measurement obtained in this flow phantom is accurate at low flow rates. However, ultrasound velocity measurement should be performed under a careful considerations of PRF and Doppler gain settings, especially at higher flow rates.

• 한국항공운항학회지
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• 제22권1호
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• pp.1-6
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• 2014

In this paper, controller propose to prevent compressor surge and improve the transient response of the fuel flow control system of turbojet engine. Turbojet engine controller is designed by applying Artificial Neural Network PID control algorithm and make an inference by applying Levenberg-Marquartdt Error Back Propagation Algorithm. Artificial Neural Network inference results are used as the fuel flow control inputs to prevent compressor surge and flame-out for turbojet engine for UAV. High Gain Observer is used to estimate to compressor rotation speed of turbojet engine. Using MATLAB to perform computer simulations verified the performance of the proposed controller. Response characteristics pursuant to the gain were analyzed by simulation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.121-126
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• 1993

Artificial muscle actuators are used in various fields. Especially, they are applied to the power assist circuit to make use of their characteristics. The purpose of this paper is to and analyze the power assist circuit using an artificial muscle actuator. As a result, it is found that the operating feeling of the power assist circuit depends mainly on the flow gain of the pneumatic servo valve. The required flow gain is calculated from the proposed model, and the experimental results agreed with the calculated results.

• 제어로봇시스템학회논문지
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• 제7권7호
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• pp.567-573
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• 2001

A real-time HVAC system is proposed which implements real-time control of thermal environment for virtual reality. It consists of a pair of hot and cold loops that serve as thermal reservoirs, and a mixing box to mix hot and cold air streams flowing if from loops. Their flow rates are controlled in real-time to meet a set temperature and flow rate. A cascade control algorithm along with gain scheduling is applied to the system and test results shows that the closed-loop response approached set values within 3 to 4 seconds.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.900-904
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• 1991

It is important and difficult to control the steam temperature in the once through boiler. Generally, steam temperature of once through boiler not only is controlled by boiler spray water flow, but also is influenced by feed water flow and fuel flow. So we have to make the same gain of fuel flow controller and feed water flow controller. This paper is shown the design and test of steam temperature and feed water flow control system for once through boiler in pusan thermal power plant.

• 한국초등과학교육학회지:초등과학교육
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• 제34권4호
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• pp.357-371
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• 2015

Even after learning electric current, elementary school students have various non-scientific conceptions and difficulties. Because flow of charge is not visible. Also elementary school students do not learn theory but phenomena, so they cannot transfer theoretical perspective to new situation. In this research, we have designed instruction based on PhET simulation visualizing flow of electric charge and applied it to 37 science-gifted students in elementary school for measuring conceptual understanding. As a result, six out of the seven Hake gains of question set are high gain and just one is middle gain because the students have understood the flow pattern of the charge through circuit elements such as light bulbs, wire, as well as battery with PhET simulation and it gives a chance to create various questions spontaneously about electric current. Also they become able to do spontaneous mental simulation without PhET simulation about flow of charges. This research, suggest that developed materials using PhET simulation could be used as not only program for gifted students in elementary school, but also the electrical circuit section in an elementary science curriculum.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1211-1212
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• 2011