• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.516-521
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• 1993

In order to hold a underwater vehicle at a depth, we can modulate buoyancy that acts on the underwater vehicle. In this research, by using a ballon, we was able to generate buoyancy that could control depth in which vehicle was operate. And in order to control flux of air that was flowed in balloon, we used solenoid valve, relief valve and so on. We derived differential equations of volume of balloon, pressure of inside of balloon, dynamic of underwater vehicle, and air flux for the simulation and linearized these differential equation. So we designed LQG/LTR controller, and applied the controller to nonlinear system. Through the simulation, we compares the nonlinear system with the linear system and investigated the operation of solenoid valve.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2771-2776
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• 2008

AOV is fluid capacity and fluid pressure control in nuclear power plant with heating power plant. The control valve in order channel to control a high differential pressure developed in the form which is complicated and precise control form. Form the research which sees in order description below analyzed the performance comparison which follows in trim forms of the control valve with CFD. The Result, multi-stage trim are a fluid kinetic energy small will prevent damages of AOV.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.448-448
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• 2000

This paper deals with dynamic behaviour analysis for pipeline inspection gauge (PIG) flow control in natural gas pipeline. The dynamic behaviour of the PIG is depending on the different Pressure between the rear and nose parts, which is generated by injected gas flow behind PIG's tail and expelled gas flow in front of its nose. To analyze the dynamic behaviour characteristics such as gas flow in pipeline, and the PIG's position and velocity, mathematical model is derived as two types of a nonlinear hyperbolic partial differential equation for unsteady flow analysis of the PIG driving and expelled gas, and nonhomogeneous differential equation for dynamic analysis of PIG. The nonlinear equation is solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used when we solve the steady flow equations to get initial flow values and the dynamic equation of PIG. The gas upstream and downstream of PIG are divided into a number of elements of equal length. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. The simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of PIG with different operational conditions of pipeline.

• 설비공학논문집
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• 제26권7호
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• pp.343-350
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• 2014

Regardless of the building design scenarios, evaluation of high-rise buildings required to have smoke-proof enclosures that are provided with a smoke management system. The goal of the smoke management system design is to make sure the pressure differentials at every story within the building fall within the allowable pressure range. If the minimum design pressure is not met, smoke may enter the stair. If the provided pressure is too great, it becomes difficult for occupants to open the doors, while attempting to egress. Ensuring that the pressure differential between the vestibule and the floor is within the prescribed range becomes challenging, due to natural effects on the building, such as the stack effect. In this research, smokeproof enclosure design scenarios were evaluated; and as a result, separation levels for compartmentation were deduced, in the balancing of pressurized-vestibule smoke control systems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.46.3-46
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• 2002

Most of the process control algorithms in practice are based on the finite dimensional control theory. However, many chemical processes are described by partial differential equations (PDE's) and are infinite dimensional in nature due to spatial variation. Especially when the convection is dominant and thus diffusion can be ignored, chemical processes that are described by a system of first order hyperbolic PDE's. Such processes include tubular reactors, fixed bed reactors and pressure swinging adsorption. Conventionally such infinite dimensional systems described by PDE's are controlled by finite dimensional controllers that are designed through finite dimensional reduction of the process m...

• 한국화재소방학회논문지
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• 제32권4호
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• pp.69-74
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• 2018

본 연구에서는 기존 제연설비의 문제점 개선 및 제연설비의 성능극대화를 위해 제연구역의 압력변화에 따라 풍량제어가 가능한 배출댐퍼를 개발하였으며, 개발 댐퍼의 효용성 검증과 상용화를 위해 성능시험을 실시하였다. 시험결과로부터 개발 배출댐퍼에 의해 급기량이 약 1 ~ 5% 정도 더 증가되는 것으로 나타났고, 제연구역에는 송풍기의 설계풍량 이상의 안정적인 풍량이 공급됨으로 풍량제어 배출댐퍼의 효용성이 입증되었다. 풍량제어 배출댐퍼의 원천기술을 확보하였다.

• 한국공작기계학회논문집
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• 제13권1호
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• pp.63-68
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• 2004

Recently ER fluids are put to practical use in fluid power industry field. As only with electrical signal change to the valve in which ER fluid flowing, ER fluid flow is controlled, so devepment of simple ER valves have been tried. In this case a technical problem is to check the pressure drop caused from flow rate change in valves because the pressure drop is very small. In this study ER valves are designed and manufactured, and small pressure drop induced from flow rate change is checked by pressure transducer which is made with appling strain gage. The ER valves and pressure drop check method are considered to be applied to the fluid power industry.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2005년도 추계학술대회 논문집
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• pp.111-116
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• 2005

An automobile engine has the Positive Crankcase Ventilation system (PCV system) for preventing air pollution as the environmental problem is important In this system, a PCV valve is the most important component to control the flow rate of Blowby gas which is generated by various engine powers. But, in the working place, the design of a PCV valve is very difficult because of interaction between fluid and solid motions. In this study, we investigated fluid flow characteristics using re-meshing method of a CFD technique to simulate spool behavior. As the results, a spool is periodically oscillated with time and is largely oscillated in proportion to the differential pressure between inlet and outlet. And, although the velocity at the orifice increases with the differential pressure, the flow rate of the outlet decreases. This research may give PCV designers visual flow information to help them

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2005년도 춘계학술논문발표회 논문집
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• pp.138-144
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• 2005

• 드라이브 ㆍ 컨트롤
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• 제16권2호
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• pp.30-35
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• 2019

EPPR (Electro-hydraulic Proportional Pressure Reducing) valves are pressure control valves. In this study, an independent metering valve (IMV), which is a combination of a spool valve opened and closed with the help of an EPPR valve, was discussed. The overall performance of the valve (IMV) was obtained by the respective modeling and simulation of the system. The valve investigated in this study is to be used for independent metering of hydraulic excavator actuator e.g. boom, arm, bucket etc. To design the model, continuity equations and force balance equations were used. The set of differential equations were then simulated in Simulink using ODE45 option in the configuration toolbox. The valve has to be able to control the flow rate going in and out of the cylinder separately, which is why the particular configuration was needed and selected.