• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1176-1185
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• 2016

This paper proposes a new output voltage control scheme based on the SoC variation of the battery energy storage system (BESS) applicable for the stand-alone DC microgrid. The proposed control scheme provides relatively lower variation of the DC grid voltage than the conventional droop method. The performance of proposed control scheme was verified through computer simulations for a typical stand-alone DC microgrid which consists of BESS, photo-voltaic (PV) panel, engine generator (EG), and DC load. A scaled hardware prototype for the stand-alone DC microgrid with DSP controller was set up in the lab, and the proposed control algorithm was installed in the DSP controller. The test results were compared with the simulation results for performance verification and actual system implementation.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.32-35
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• 1997

A recent development in the Flat Panel Display(FPD) industry requires an auto-alignment system which is operated in high speed and high precision. In the FPD production process, aligning photo-mask with respect to guide mark printed in the glass should be accomplished in the accuracy of sub-micron order. So the system has high bandwidth and needs a dedicated control system which is fast and robust enough to control linear motors in precise manner. Proposed auto-alignment system structure in this presentation which consists of the master controller board, the DSP position controller board which controls 3 axis precision linear motors, the servo system and the man machine interface software. Designed and tuned under repeated experiments, the proposed system showed a reasonable performance in the aspect of rise time and steady state error.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.449-454
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• 2003

In this paper, GU environmental controller is implemented with USB(Universal serial bus) IF(interface). Especially, the performance examination of ultrasound diagnostic device which connects external USB port with front panel is automatically inspected by VC++ examination program. The test program minimizes the operation of inspector with making the examined result audible or visible, and maximizes the productivity of custom device. The GUI environmental controller controls a standard keyboard, a track ball with dedicated buttons to emulate a standard two-button mouse, switches, rotary encoders, an analog potentiometer group, two alpha-numeric displays. and a touch screen; all of which generate events for the host.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1997-1998
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• 2006

In this paper, we propose a remote control system which is used by internet network system in the small water booster supply. So far, TMTC(Tele Metering Tele Control) has been used to control and monitor small water booster pump. But it is possible and easy to control and observe local booster panel with the rapid development of internet, This new system is to provide operators and managers with sufficient information and control in order to implement the operation in an efficient and economical way. This system consists of three parts that are controller, netpump server and netview client. Controller has a dual architecture. The motive for installing controller is the continuous production and supply of drinking water.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.153-156
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• 2000

This paper presents an PID type fuzzy based method for nohnear engine idle controller The output is a duty cycle(DC) for driving a idle speed cont개l valve(1SCV). For precise control of SI engine, the CPS sensor and coolant temperature are used. Visual C* language is used to make simulation panel for the fast and precise idle speed control. The dSPACE board and supported Control desk program is used in experiment ta the same purpose as simulation. The experimental results have a good agreement with simulation ones.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.168-171
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• 2009

The solar lighting system has been popular in these days. It is composed of solar panel, controller, and battery. The battery is charged during the day time, and discharged at the night time. The battery status should be carefully controlled in order to guarantee the safe operation. If there were measurement noise or system noise, the performance of controller could be degraded. In this paper, the state estimator design in the noisy environment is proposed. The proposed system shows the excellent tracking performance under in harsh conditions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.237-243
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• 2016

Recently, technologies that produce biofuels from microalgae are being studied worldwide. It is necessary to significantly reduce the production costs of biofuels from microalgae for economic reasons. In this study, the growth curve of the microalgae was obtained using the batch-culture method, and the specific growth rate was predicted using the regression method. Based on the culture conditions of the estimated specific growth rate, the turbidity of the microalgae in the flat panel photobioreactor (PBR) was measured. Furthermore, an on-off control scheme was applied to the flat panel PBR in order to culture the microalgae continuously on the basis of turbidity. The parameters of the on-off control system were displayed by LabView. The on-off scheme of peristaltic pump was controlled based on the turbidity in the PBR. In addition, the turbidity values of growth curves were compared and analyzed in the continuous culture process using the on-off controller.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1209-1218
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• 2006

Precision servomechanisms are widely used in machine tool, semiconductor and flat panel display industries. It is important to improve contouring accuracy in high-precision servomechanisms. In order to improve the contouring accuracy, cross-coupled control systems have been proposed. However, it is very difficult to select the controller parameters because cross-coupled control systems are multivariable, nonlinear and time-varying systems. In this paper, in order to improve contouring accuracy of a biaxial servomechanism, a cross-coupled controller is adopted and an optimal tuning procedure based on an integrated design concept is proposed. Strict mathematical modeling and identification process of a servomechanism are performed. An optimal tuning problem is formulated as a nonlinear constrained optimization problem including the relevant controller parameters of the servomechanism. The objective of the optimal tuning procedure is to minimize both the contour error and the settling time while satisfying constraints such as the relative stability and maximum overshoot conditions, etc. The effectiveness of the proposed optimal tuning procedure is verified through experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.28-35
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• 2001

In this paper, an electronic starter and controller are develor:ed for blinking and color variation oI:'||'&'||'pound;fations of fluorescent ]arrps, which would be suitElble for use in an advertising panel. The deve1oporl electrornc starters enable single-pulse ignition for fluorescent lamps of 2O-4Q[W] according to the start signal of controller, and the lamp life is e;.qxccted to go beyond 3,OCO hours with blinking o]:ffations for minimum 0.2[s]. Also, the controller based on a micro-controller can handle up to 128 fluorescent lanlpS and have ten modes of blinking pattems and 7-color variation mxles.

• Composites Research
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• v.13 no.5
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• pp.50-59
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• 2000

In this paper, two methods to suppress flutter of the composite panel are examined. First, in the active control method, a controller based on the linear optimal control theory is designed and control input voltage is applied on the actuators and a PZT is used as actuator. Second, a new technique, passive suppression scheme, is suggested for suppression of the nonlinear panel flutter. In the passive suppression scheme, a shunt circuit which consists of inductor-resistor is used to increase damping of the system and as a result the flutter can be attenuated. A passive damping technology, which is believed to be more robust suppression system in practical operation, requires very little or no electrical power and additional apparatuses such as sensor system and controller are not needed. To achieve the great actuating force/damping effect, the optimal shape and location of the actuators are determined by using genetic algorithms. The governing equations are derived by using extended Hamilton's principle. They are based on the nonlinear von Karman strain-displacement relationship for the panel structure and quasi-steady first-order piston theory for the supersonic airflow. The discretized finite element equations are obtained by using 4-node conforming plate element. A modal reduction is performed to the finite element equations in order to suppress the panel flutter effectively and nonlinear-coupled modal equations are obtained. Numerical suppression results, which are based on the reduced nonlinear modal equations, are presented in time domain by using Newmark nonlinear time integration method.