• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.625-632
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• 2014

It is required a lot of strength in aquaculture, such as dragging up or moving heavy loads. So, a helper system like excavator at construction is need for fishermen. As most of HFMSC(Hydraulic Fishery Managing Small Crane)s are operated based on ON/OFF control, it can make sway the contents in the crane. In worse case, it could threaten workers. In this paper, we development the MICOM based controller which can reduce the swing sway. This paper describes the hydraulic characteristics, the design method of controller and the control algorithms. And, the proposed controller show the efficiency to carry out the experimental validation.

• Transactions of The Korea Fluid Power Systems Society
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• v.2 no.2
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• pp.8-13
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• 2005

This paper investigates a fast, accurate and inexpensive hydraulic motor speed control system using high speed on-off solenoid valves. In order to retain the advantages of the two position valve and obtain better performance, the valves are operated by pulse width modulation(PWM) control. PWM signal is generated from a LabWIEW program in microcomputer in order to set up various duty ratio and frequency of carrier wave in PWM signal with varying system parameters. As the results of experiments, the speed control of a hydraulic motor was successfully implemented using on-off solenoid valves. In order to attenuate the pressure ripple and speed variation due to discontinuously controlled flow through the on-off valves, a resonator hose fabricated for automobile power steering system was connected between the valve and a hydraulic motor. From experimental results obtained in the hydraulic motor system with a resonator hose, it was ascertained that the resonator hose showed excellent performances in reducing pressure ripple and motor speed variation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.6
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• pp.1282-1289
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• 1988

It has recently shown that a solenoid valve can be utilized in a hydraulic position-control system by discontinuous control methods. The objective of this study is to investigate the effects of solenoid valves on the response characteristics of a hydraulic position-control system by applying two kinds of discontinuous control methods i.e., Simple On-Off(SOF) and Pulsating On-Off(POF) controls. Three types of solenoid valves i.e., low-frequency, closed-center type(LF/C), low-frequency, tandem-center type(LF/T) were used in this study. Effects of loading conditions and control parameters on the response characteristics were experimentally examined and compared each other. Pressure transients within the actuator were also studied.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.238-239
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• 2011

겨울철이나 추운지역에서는 선박용 및 건축용의 창유리에 결로, 결빙현상이 쉽게 발생하고 쾌적한 시야확보 및 청결유지를 방해한다. 이를 방지하기 위해 발열유리 온도제어 시스템을 사용한다. 기존의 아날로그 발열유리 시스템은 정확한 온도설정, 상태표시 및 고장검지가 어렵다. 또한 통신에 의한 중앙제어가 어렵다. 이와 같은 기존시스템의 단점을 해결하기위해 본 논문에서는 마이크로프로세서에 의한 TRIAC제어를 이용하여 4[kW]급 발열유리의 온도제어 시스템을 설계한다. 그리고 실험을 통해 그 성능을 확인하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.727-730
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• 2009

유비쿼터스는 어떤 기기나 사물에 컴퓨터 칩을 내장시켜 각 사물들이 컴퓨터네트워크에 접속되어 통신을 가능하도록 해주는 정보 기술(IT ; Information Technology)을 총칭하는 것으로, 유비쿼터스 환경이란 결국 사물들의 네트워크를 의미한다. 막연한 유비쿼터스를 보다 현실성 있게 접근 할 수 있도록 휴대폰의 SMS기능을 활용한 "제어기(Controller)"를 설계하고 시험 하였다. 사용자가 휴대폰의 문자 메시지(SMS) 신호를 제어기의 중앙처리장치에 전달하고 이 신호를 처리해서 Relay를 ON/OFF 할 수 있도록 구성 되어 Relay에 연결된 외부기기 즉, 조명, 선풍기, 히터 등 가전기기 등의 전원을 ON/OFF한다. 이를 통해서 일반인들도 간단하고 쉽게 원격제어를 체험 할 수 있고 원한다면 얼마든지 다양한 종류의 전기기기 제어를 할 수 있다.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3150-3158
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• 1997

In the ATM networks, there are two method in traffic control as schemes to improve the quality of service; one is the reactive control after congestion and the other is the preventive control before congestion. The preventive control include the CAC(Connection Admission Control), the UPC(Usage Parameter Control), the NPC(Network Parameter Control) and the PC(Priority co ntrol). In this paper, we propose an efficient UPC algorithm that has a complex structure using the Jumping window algorithm within the Leaky Bucket algorithm. The proposed algorithm controls peak hit rate by the Leaky Bucket algorithm, then it does the traffic control to evaluate by the Jumping Window whether violates mean bit rate or not. As we assume On/Off traffic source model, our simulation results showed cell loss rate less than the pre-existential Leaky Bucket algorithm method, and it could decrease the demanded Bucket size.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1736-1740
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• 2003

POSCO Kwang-Yang Works #2 Cold Rolling Mill RCL has the main hydraulic system that controlled on/off control method. In the aspect of the consumption of electrical energy this system has some problem. So, we present a continuous control method instead of on/off control method that controls the pressure of main hydraulic system with saving the electric energy.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.432-439
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• 1999

In this paper, an off-line programming(OLP) system is presented as the three dimensional graphic simulator and one of the human-robot interface systems for industrial robots. The OLP system has been especially developed to testify robot programs visually using three dimensional geometric modeling and graphics technologies in personal computes. A special feature is its capability of collision detection and of comparing performance of control algorithms. This paper places the focus on the structure and major characteristic of OLP system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.2
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• pp.179-185
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• 2015

The main objective of thermal design for a space-borne FPA(Focal Plane Assembly) is to provide stable thermal environment during imaging operation and thus maintain the image quality. An FPA must be maintained within its operating temperature range and cooled down to its initial temperature soon enough for the next imaging operation. This paper describes the study result on performing trade-off studies for FPA thermal design by using simplified thermal node analysis about FPA preliminary design. It also describes the verification results of the study by comparing thermal analysis results and trade-off study results. According to results, we can conclude that this approach is useful for simple and quick trade-off studies without thermal analysis based on thermal math models.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1211-1217
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• 2001

This paper presnts a controller for the heat capacity of thermal storage systems using off-peak electricity which is composed of an identifier using neural networks and a storage time adjuster in order to store exactly the required thermal energy without loss. Since thermal storage systems have nonlinear characteristics and large time constant, even if we predict the heating load accurately, it is very difficult to store exactly the required thermal energy. Thus, in the neural network for the identifier, the adaptive learning rate for high learning speed and bit inputs based on state changes of thermal storage power source are used. Also a hardware for the controller using a microprocessor is developed. The performance of the proposed controller is shown by experiment.