• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.284-289
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• 2003

The electric furnace, inside which the desired temperature is kept by the generated heat, is known to be a difficult system to control and model exactly because system parameters and response delayed time are varied as the temperature and positions are changed. In this study, the GPCEW (generalized predictive control with exponential weight), which always guarantees the stability of the closed loop system and can be effectively applied to the internally unstable system, was introduced to the ceramic drying electric furnace and was verified by showing its temperature tracking performance experimentally.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.442-447
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• 1988

To keep comfortable indoor condition, the existing air conditioning system is controlled by the ON/OFF temperature controller. The PID control unit is developed to control temperature and humidity simultaneously, and the Air-conditioning control system is transferred from the ON/OFF temperature controller to the PID control unit for experiment. As a result of this experiment, the PID control unit reduced energy consumption compared with the ON/OFF control unit.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.435-440
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• 2009

For the effective control of a $CO_2$ air-conditioning system, the system high-side pressure algorithm, the indoor temperature algorithm, and the outdoor fan algorithm were developed. The system high-side pressure algorithm was composed of the setpoint algorithm, the reset algorithm, and the electronic expansion valve control algorithm. The indoor temperature algorithm was composed of the compressor control algorithm and the indoor fan control algorithm. These algorithms were tested by using mathematical models developed from the previous study. Results from the setpoint step change test and the disturbance test showed good control performances. Therefore, algorithms developed in this study may practically used for the control of a $CO_2$ air-conditioning system.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.156-160
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• 2018

In the paper, a kind of self-tuning PID control system is designed to keep the honing coolant temperature constant in the process of automobile engine production. The conventional PID control method and the Fuzzy PID control method both are used to design and make the simulation experiment in Matlab. According to the simulation result, the performance of Fuzzy PID control method is obviously better. The Fuzzy PID control system can react faster to get the target temperature and resume normal when external conditions exchanged.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.210-215
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• 2004

: A DNA analysis system based on fluorescence analysis has to have a DNA amplifying thermal cycle system. DNA amplification is executed by the temperature control. Accuracy of fluorescence analysis is influenced by the temperature control technology. For that reason, the temperature control is core technology in developing the DNA analysis system. Therefore, the objective of this paper is to develop the hardware to apply thermoelectric module to the DNA amplifying thermal cycle system. In order to verify the developed hardware for controlling the temperature of thermoelectric module, a DNA amplifying thermal cycle test was performed. From the test, the developed hardware controlled the temperature of thermoelectric module successfully. Therefore, it is expected that the developed hardware can be applied to the DNA amplifying thermal cycle system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1371-1376
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• 2003

In the thermal power plant, the main steam temperature is typically regulated by the fuel flow rate and the spray flow rate, and the reheater steam temperature is regulated by the gas recirculation flow rate. However, Strictly maintaining the steam temperature can be difficult due to heating value variation to the fuel source, time delay changes in the main steam temperature, the change of the dynamic characteristics in the reheater. Up to the present time, PID Controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper focuses on tuning of the 2-DOF PID Controller on the DCS for steam temperature control using immune based multiobjective approach. The stable range of a 2-DOF parameter for only this system could be found for the start-up procedure and this parameter could be used for the tuning problem. Therefore tuning technique of multiobjective based on immune network algorithms in this paper can be used effectively in tuning 2-DOF PID controllers.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.111.2-111
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• 2002

The temperature of Kimchi-refrigerator is controlled by the wishing condition the original taste of Kimchi, the fast precocity of Kimchi. In this paper we studied the controlling temperature of Kimchi-refrigerator. The controlling temperature of Kimchi refrigerator is based on microcontroller which control On/Off. In this paper, Fuzzy logic was used to control the temperature of Kimchi-refrigeration. I will apply to fuzzy logic control to have simple rule control on the place of On-Off control system in the past. This device controls the in order to measure several temperature of two refrigeration plant in Kimchi refrigerator solenoid valve in refrigeration plant. A solenoid valve...

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1201-1204
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• 2004

This paper suggests a DCS (Distributed Control System) model for steam temperature system of the thermal power plant. The model calculated within sectional range is linear. In order to calculate mathematical models, the system is partitioned into two or three sectors according to its thermal conditions, that is, saturated water/steam and superheating state. It is divided into three sections; water supply, steam generation and steam heating loop. The steam heating loop is called 'superheater' or steam temperature system. Water spray supply is the control input. A first order linear model is extracted. For linear approach, sectional linearization is achieved. Modeling methodology is a decomposition-synthetic technique. Superheater is composed of several tube-blocks. For this block, linear input-output model is to be calculated. Each tiny model has its transfer function. By expanding these block models to total system, synthetic DCS linear models are derived. Control instrument include/exclude models are also considered. The resultant models include thermal combustion conditions, and applicable to practical plant engineering field.

• Smart Structures and Systems
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• v.24 no.1
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• pp.1-14
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• 2019

Transmission tower-line system is one of most critical lifeline systems to cities. However, it is found that the transmission tower-line system is prone to be damaged by earthquakes in past decades. To mitigate seismic demands, this study introduces a tuned-mass damper (TMD) using superelastic shape memory alloy (SMA) spring for the system. In addition, considering the dynamic characteristics of both tower-line system and SMA are affected by temperature change. Particular attention is paid on the effect of temperature variation on seismic behavior. In doing so, the SMA-TMD is installed into the system, and its properties are optimized through parametric analyses. The considered temperature range is from -40 to $40^{\circ}C$. The seismic control effect of using SMA-TMD is investigated under the considered temperatures. Interested seismic performance indices include peak displacement and peak acceleration at the tower top and the height-wise deformation. Parametric analyses on seismic intensity and frequency ratio were carried out as well. This study indicates that the nonlinear behavior of SMA-TMD is critical to the control effect, and proper tuning before application is advisable. Seismic demand mitigation is always achieved in this wide temperature range, and the control effect is increased at high temperatures.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.11
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• pp.80-92
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• 1997

This research focuses onan efficient control method of temperature for multiple points using only one processor. For a yarn production system, the surface temperature control of heaters are very important for quality control. Therefore, we designed a temperature controller for a draw and twist machine and applied Fuzzy-PWM algorithm to the controller. If we use a processor for the temperature control of multiple points with the conventional ON/OFF control, the control performance of the system becomes poor. To overcome these problems, we developed a new Fuzzy-PWM algorithm for the adjustment of power rate to the heaters in the conventional ON/OFF control. It is shown that this algorithm has the same effects as the PID algorithm for the temperature control of each point. The proposed algorithm is robust against the production condition and environment such as the reference temperature and the thickness of yarn, since the power rate to the heater is adjusted by Fuzzy Rules derived from the values of the reference termperatureand the thickness of yarn. To obtain optimal Fuzzy rulees, the control simulations are perfodrmed through the modelling of the heater and simulation of Fuzzy rules. This algorithm is applied for the multiple pont temperature controller and showed satisfactory performance.