• The Korean Journal of Pain
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• v.4 no.2
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• pp.142-146
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• 1991

One hundred twenty patients with acute and chronic pain treated by a low power laser were divided into several groups by their pathology and evaluated according to their response rate to laser therapy through a follow-up study. 1) The ages of the patients were between the early twenties and late forties (71.7%), and there was no differences between sexes. 2) The spinal pathology group was the most common(52.5%) and the articular pathology group occupied next (14.2%). 3) The average duration of Laser therapy was about 20 days and response to the therapy appeared about the eighth day. 4) The response to the therapy in the spinal pathology group appeared about the eighth day and the average duration of therapy was about 18 days. 5) The response to the therapy in the articular pathology group appeared about the eighth day and the average duration of therapy was about 28 days. 6) The response rate of the spinal pathology group was 81.0%, and remarkable symptom relief was noted when compaired to a 58.7% response rate in the control group, 7) The response rate of the articular pathology group was 82.4%, which was similar to the control group. 8) The response rate of the miscellaneous group was 87.0%, and remarkable symptom relief was noted when compaired to a 66.7A response rate in the control group. 9) The mean response rate of all patients treated by a low power laser was 82.5% and that of the control group was 70.5%. Laser therary proved to be an effective treatment modality for acute and chronic pain.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.192-201
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• 1997

The feedback control scheme of the pressure control system of the rear wheel steering gear which has relatively large volume and sprung load was built up in order to improve th response characteristic of the system. The control algorithm chosen was a feedback compensator joined by a feedfoward compensator and the model matching method was used in the process of control system design. The structures and properties of the reference models were inspected and the parameters of the controller were decided. The improvement of the response characteristic of the pressure control valve by means of the feedback control is affirmed. Particularly, when the order of the system model is higher than the 2nd order, the effectiveness of the feedback control on the improvement of the response characteristic of the valve is distinct. And the convenience of the model matching method is the process of control system design is confirmed as well.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.261-263
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• 1988

In this study, the several control laws and switching planes are considered to eliminate the steady state error and to obtain the rapid response for variable structure control systems. An elimination algorithm is achieved by combination with each other control law, and the type of control law having the most rapid response is shown through some simulations.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.3
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• pp.130-142
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• 2018

We use heat pumps with thermal storage system to reduce peak usage of electric power during winters and summers. A heat pump stores thermal energy in a thermal storage tank during the night, to meet load requirements during the day. This system stabilizes the supply and demand of electric power; moreover by utilizing the inexpensive midnight electric power, thus making it cost effective. In this study, we propose a system wherein the thermal storage tank and heat pump are modeled using the TRNSYS, whereas the control simulations are performed by (i) conventional control methods (i.e., thermal storage priority method and heat pump priority method); (ii) region control method, which operates at the optimal part load ratio of the heat pump; (iii) load response control method, which minimizes operating cost responding to load; and (iv) dynamic programming method, which runs the system by following the minimum cost path. We observed that the electricity cost using the region control method, load response control approach, and dynamic programing method was lower compared to using conventional control techniques. According to the annual simulation results, the electricity cost utilizing the load response control method is 43% and 4.4% lower than those obtained by the conventional techniques. We can note that the result related to the power cost was similar to that obtained by the dynamic programming method based on the load prediction. We can, therefore, conclude that the load response control method turned out to be more advantageous when compared to the conventional techniques regarding power consumption and electricity costs.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.52-61
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• 1999

This paper proposes the application of fuzzy control for high performance control of induction motor using electric vehicles. A fuzzy controller converts a set of liguistic rules based on expert knowledge into a automatic control strategy. Such controllers have often been found superior to conventional controllers especially when information being processed is inexact and uncertain. A system with fast torque response is very beneficial in applications where direct self control (DSC) is highly desirable. The response of DSC is slower during startup and during change in command torque. Fuzzy control is used for implementation of DSC to improve its slow response. Simulation implementation of the fuzzy logic controller was carried out to verify the behavior of the controller. The simulation results with fuzzy control are compared with those of the conventional DSC. The starting flux and torque response and the responses to the step changes in command torque with fuzzy implementation show a considerable improvement over the conventional control. The steady state responses in both the cases are the same.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.203-206
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• 2006

In this study, the method of designing the flexible wing model which will be used for wind tunnel testing of gust response alleviation system was presented. The design concept proposed herein was validated by performing the modal testing of the flexible wing model manufactured for demonstration purpose. In addition, the study on the gust response alleviation using flexible wing control surface was performed. For this purpose, optimal control with output feedback was adopted for designing the control surface controller, and the effects of gust response alleviation was validated by performing the numerical simulation for the representative flexible wing model. The methods proposed and validated in this study can be applied for wind tunnel testing of the flexible wing for gust response alleviation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1991.10a
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• pp.53-58
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• 1991

This paper presents the speed control of DC motor based on deadbeat response method. Since 송 deadbeat response systems are characterized by the discrete time control, the instabiliby of the systems caused by saturation and time lag problems is inevitable. In order to release these problems, we propose a compensator utilizing the predictive control so that the fast response can be also achieved in the saturation state. Experimental results demonstrated that outputs are able to settle final values in on sampling time for unsaturated reference inputs. For saturated reference inputs, outputs take one sampling time after getting free from the saturation state. Further we are able to settle the fast response with suppressed overshoot by appling the predictive control.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.416-418
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• 1997

Stable power source and fast control response are important for the generator excitation system. To stabilize the control of excitation circuit the PI controller for excitation current has been used. But the response of the system with this conventional control technique is very poor, especially in transient response with a predictive current control, the response of the excitation system can be improved. In this study, it is verified by the PSIM simulation.

• Structural Engineering and Mechanics
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• v.15 no.2
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• pp.239-248
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• 2003

The dynamic response analysis of closed loop control system based on probability for the intelligent truss structures with random parameters is presented. The expressions of numerical characteristics of structural dynamic response of closed loop control system are derived by means of the mode superposition method, in which the randomness of physical parameters of structural materials, geometric dimensions of active bars and passive bars, applied loads and control forces are considered simultaneously. The influences of the randomness of them on structural dynamic response are inspected by several engineering examples and some significant conclusions are obtained.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.597-603
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• 2001

Control of pressure transients in a hydraulic system may be important and necessary to avoid failures and to improve the efficiency of operation. Flow restricting devices can result in a decrease in the peak pressure, but may change the response time. The response time has an important effect on both operator and operator perceived smoothness. The response time should correspond to how fast a system responds to a given disturbance at the system boundary. Occasionally the appropriate response time is not easily determined. This study is on the response time characteristics in the hydraulic system studied for the control of response time.