• Journal of Power System Engineering
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• v.12 no.5
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• pp.65-70
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• 2008

The purpose of this study is to verify availability of the acoustic emission in-situ monitoring method to the internal leak and operating conditions of the turbine major valves relating to safety for turbine operating and prevention of turbine trouble at nuclear power plants. In this study, acoustic emission tests are performed when the pressurized electro-hydraulic control oil flowed through turbine electro-hydraulic controller oil check valve and turbine power/trip fluid solenoid valve in the condition of actual turbine operating. The acoustic emission method was applied to the valves at the site, and the background noise was measured far the abnormal plant condition. To judge for the leak existence ell the object valves, voltage analysis and frequency analysis of acoustic signal emitted from infernal leak in the valve operating condition are performed. It was conformed that acoustic emission method could monitor for valve internal leak to high sensitivity.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.168-175
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• 1995

A robust speed control algorithm under disturbances and reference change is developed using the self tuning control method in order to control induction motors. The method incorporates the concepts of the well known internal model principle and the annihilator polynomial. The effectiveness of the method is evaluated through the speed control experimental results of an induction motor for refernce change and arbitrary distrbance.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.578-582
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• 1994

In this paper reconstructing the internal resistivity and relative permittivity distribution is discussed. The iterative reconstruction method based on Finite Element method and Newton method were used to reconstruct both of resistivity ind permittivity distribution. The Finite Element model of impedance distribution is built in complex field of resistivity and capacitive medium. The reconstruction results based on computer simulated data and experimental data are presented.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.351-361
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• 2001

In this paper, a generalized framework called as robust internal-loop compensator(RIC) is presented, and by using this, a structural design method of sliding of sliding mode controller is proposed. First, a general sliding mode controller is derived and a stabilizing control input is designed based on Lyapunov redesign for the system in the presence of uncertainty and disturbance. And adopting the internal model following control, RIC is proposed. Next, using the structural characteristics of the proposed RIC, disturbance attenuation characteristics are analyzed and the performance of the closed-loop system is predicted. Through this analysis, it is shown that if the control gain of RIC is increased by N times, the magnitude of error is reduced to its 1/N. the proposed method is verified through experiments using a high-precision positioning system and the performance is evaluated.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.2-8
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• 2002

This paper discusses haptic display for grasping a virtual object by two fingers. Much research has been done on fundamental analysis for stability of haptic display. But it is difficult to apply the results immediately to grasping situations by two fingers, since the studies usually deal with a single device and a single object and the fingertip force in grasping situations has two components, internal and external components. The conventional methods, which specify the coupling impedance at each contact point separately, have no other alternative but to specify the impedance for the sum of the internal and external components. So even if only the impedance for the external force should be changed, the impedance for the internal force is also changed at the same time. In this paper, a new method, in which the coupling impedance is specified separately for the internal and external forces, is proposed and the stability of the proposed method is discussed using passivity analysis for 1 -DOF(Degree-Of-Freedom) system. Finally, some experiments are performed to study the effects of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.539-542
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• 1996

The forces exerted on an object by the end-effectors of multi-manipulators are decomposed into the motion-inducing force and the internal force. Motion-inducing force effects the motion of an object and internal force can't effect it. The motion of an object can't track exactly the desired motion because of internal force component, therefore internal force component must be considered. In this paper using the resolved acceleration control method and the fact that internal force lies in the null space of jacobian matrix, we construct independently the position, motion-inducing force and internal force controller. Secondly we construct the robust controller to preserve the robustness with respect to the uncertainty of manipulator parameters.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.235-240
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• 2002

We report the new method for the screening of genetically modified potato by competitive duplex-PCR using the potato specific single oligomer primer for the internal control and CaMV 35S promoter or NOS terminator specific primers. The single oligomer primer (rAGU4A) amplify the potato specific internal control band from the homozygous potato genomic DNA in the RAPD profiles of all analyzed potato varieties. The 530 bp internal control DNA was amplified independently to CaMV 35S promoter or NOS terminator DNA and identified as repetitive or microsatellite DNA of potato (AF541972). With this new technique, the transgenic potatoes which were transformed with vectors contained the different foreign genes are analyzed. In case of the commercialized transgenic potato varieties, 'Hew Leafs', those two genetic factors are used for promoter and terminator respectively So, this new PCR technique should be a promising method of cost effective and accurate screening for the commercialized GM potatoes on market.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.193-199
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• 2011

A method to improve internal corrosion control efficiency by adding lime and carbon dioxide, which, in turn increases the Langelier Index (LI) for filtered water at a conventional drinking water treatment plant (WTP) was investigated. The SJ WTP (Q=100,000 $m^{3}$/d) has been operating an internal corrosion control system since 2006. The system has achieved stable operation through technical development and trial and error over a period of several years. As a result of the operation, the LI of treated water has increased up to 29% by adjusting pH of filtered water to 7.8 with the addition of lime and carbon dioxide. Coupon tests in the distribution system indicated that the corrosion rate has been delayed by 24% when the internal corrosion method was implemented. The increase of LI by lime and carbon dioxide has been proven to be a practical method for controlling corrosion.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.4
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• pp.175-185
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• 2002

In this paper, a new fully digital current control method of UPS inverter, which is based on an internal model control, is proposed. In the proposed control system, overshoots and oscillations due to the computation time-delay are compensated by explicit incorporation of the time-delay in the current control loop transfer function. The internal model controller is adopted to a second order deadbeat reference-to-output response which means that its response reaches the reference in two sampling time including computational time-delays. That is, the average current of filter capacitor is been exactly equal to the reference current with a time lag of two sampling intervals. Therefore, this method has an essentially overshoot free reference-to-output response with a minimum possible rise time. The effectiveness of the proposed control system has been verified by the simulation and experimental respectively. From the simulation and experimental results, the proposed system is achieved the robust characteristics to the calculation time delay and parameter variation as well as very fast dynamic performance, thus it can be effectively applied to the power supply for the critical load.

• The Journal of Internal Korean Medicine
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• v.19 no.2
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• pp.278-299
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• 1998

This study was aimed to evaluate the anti-stress effect of danchisoyosan on the rats stressed by immobilization. The experimental animals were immobilized in the stress box($5{\times}5{\times}20cm$) for 12 hours in a day during 3 days, and administered $500mg/5m{\ell}/g$ of Danchisoyosan extract for 14 days before stress. There were measured the change of body weight and organ weight under immobilized-stress. The norepinephrine, epinephrine, dopamine, serotonine contents were measured by HPLC method in rat brain. There were measured the GOT, GPT contents in serum and tissue lipid peroxidation in the brain, liver, spleen, adrenalgland, pancreas, testes, thymus, heart. The following results were obtained: 1. The change of organ weight was significantly lower in control than normal group. Sample group inhibited decreased weight from stress comparing to control group. 2. Lipid peroxidation in the liver was significantly higher in control than normal group. Sample group shows significant decrease comparing to control group. 3. Lipid peroxidation in the kidney was significantly higher in control than normal group. Sample group shows significant decrease comparing to control group. 4. GPT contents in serum was significantly higher in control than normal group. Sample up shows significant decrease comparing to control group. 5. Dopamine contents in the brain was significantly higher in control than normal group. Sample group shows significant decrease comparing to control group. 6. Serotonine contents in the brain was significantly higher in control than normal group. Sample group shows significant decrease comparing to control group.