• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.378-381
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• 2002

Instantaneous following PWM control technique is pulsed nonlinear dynamic control method. This new control technique using analog integrator is proposed to control the duty ratio D of DC-DC converter. In this control method, the duty ratio of a switch is exactly equal to or proportional to the control reference in the steady state or in a transient. Proposed control method compensates power source perturbation in one switching cycle, and the average value of the dynamic reference in one switching cycle. There is no steady state error nor dynamic error between the control reference and the average value of the switched variable. Experiments with buck converter have demonstrated the robustness of the control method and verified theoretical prediction. The control method is very general and applicable to all type PWM.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.465-465
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• 2000

The paper presents the fuzzy control technique to adjust the gain schedule in the fuzzy controller. The micro computer is designed to the fuzzy controller to execute the proportional gain with the data of the error and speed command. The gain schedule is the fuzzy set which execute based on the fuzzy rule. The gain schedule from the fuzzy controller is fed to the sinusoidal pulse width modulation (SPWM) inverter for control the response and speed of the induction motor. The induction motor coupling to the DC motor and tachogenerator which DC motor as a load. The test result of the fuzzy control technique in the open loop control, it provides a good response and in the closed loop control it can control speed in the any condition of load design

• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.11-20
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• 2021

Decontamination of systems, structures and components (SSC) during the decommissioning of a Nuclear Power Plant (NPP) can be for a variety of reasons. The main reasons for decontamination are: to reduce the contamination of SSC to a reasonably low level, to reduce the potential for the spread of contaminants into the environment and to reduce the cost of disposal due to the reduced level of contamination in a particular SSC. The decontamination technique can be aggressive or non-aggressive depending on the intent after the decontamination process. Aggressive decontamination technique is used when the intent is not to reuse the SSC while a non-aggressive decontamination technique is used with the intent of SSC reuse. For different SSCs there are different decontamination techniques that can be used, each having its own advantages and drawbacks. Metal components such as pipes in the nuclear power plant account for a large amount of nuclear wastes generated. Some of these wastes can be reused if the contaminant level is reduced to an acceptable level. Laser ablation is a non-aggressive decontamination technique that can be used to reduce the contamination in pipes to an acceptable level with no secondary waste generated during the process. The operation and control of a laser ablation device must be precise to achieve a high decontamination factor. This precision can be achieved by a well-designed motion control system. For this purpose, a motion control system was developed consisting of two parts: the first part being the precise control of the laser ablation device inside the pipe and the second part is the control of the laser ablation device outside the pipe. This paper describes the Systems Engineering approach for the development process of a motion control system for the Laser decontamination system.

• Journal of Korean Academy of Nursing
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• v.15 no.1
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• pp.76-96
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• 1985

Postoperative pain is one of the most frequently occurred pain in hospitals, but it has been underestimated because it is only a part of postoperative physiological Process and may disappear in time. It is necessary that nurses me the relaxation technique, planning and implementing by themselves independently, to reduce this postoperative pain. This study is aimed at showing the effect of relaxation technique on reduction of postoperative pain, and exploring the factors influencing postoperative. pain Fifty-seven patients with abdominal surgery who admitted in attacked D Medical Center to K University in Daegu have been studied. Of them twenty-nine were experimental group and the remaining twenty-eight were control group. This study has been conducted for collecting data through interviews and observation from August 23 to October 24, 1984. The tools of this study were two kinds: Postoperative Pain Scale is obtained from a review of references by the researcher, and relaxation technique, designed to use postoperative setting adequately, is also obtained from a review of references by the researcher. After confiriming no significant differences between the two groups, the hypotheses were statistically verified by x²-test, t-test, and pearson Correlation Coefficient. The results of this study are summerized as follows; ＊ The nam hypothesis that the experimental group who use relaxation technique will have less degree of postoperative pain than the control group who don't use relaxation technique is devided into three sub-hypotheses. 1. The first sub-hypothesis that the experimental group will have less score of postoperative pain than control group was accepted (t=7.810, p <.01). Even with controlling pain threshold, showing difference in some degree between the two groups, the experimental group has less score of postoperative pain than the control group. Therefore this confirms the acceptance of the first sub-hypothesis more strongly. 2. The second sub-hypothesis that the expermental group will have less frequency of analgesics than the control group is accepted (x²=9.85, p <.01). 3. The third sub-hypothesis that the experimental group will have less variation of pulse, respiration, and blood pressure between pre End post operative periods than the control group is rejected. So this hypothesis is reverified through comparing the variation of pulse, respiration, and blood pressure between pre and post changing Position to measure the pure effect of relaxation technique. pulse and respiration is significantly lowered in the experimental group (t=7.209, p<.01, t=3.473, p<.01), but systolic and diastolic blood pressure is not different significantly between the two groups (t= 1.309, p＞.05, t=1. 727 p>.05). Therefore the third sub-hypothesis is partially accepted. Conclusively, the researcher thinks that it is necessary that nurses should provide patients with relaxation technique to reduce postoperative pain, and to increase independence of nursing.

• The KIPS Transactions:PartA
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• v.15A no.6
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• pp.309-316
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• 2008

The mission-critical engagement control computer for air defense has to maintain its operation without any fault for a long mission time. The mission performed by large-scale and complex embedded software is extremely critical in terms of dependability and safety of computer system, and it is very important that engagement control computer has high reliability. The engagement control computer was implemented using four processors. The distributed computer composed of four processors quarantees the dependability and safety, and ASR fault-tolerant technique applied to each processor guarantees the reliability. In this paper, the mechanism and performance of ASR fault-tolerant technique are analysed. And MTBF, reliability, availability, and cost-effectiveness for ASR, DMR and TMR techniques applied to the engagement control computer are analysed. The mission-critical engagement control computer using software-based ASR fault-tolerant technique provides high reliability and fast recovery time at a low cost. The mission reliability of the engagement control computer using ASR technique in 4 processors board is almost same the reliability of the computer using TMR technique in 6 processors board. ASR technique is most suitable to the mission-critical engagement control computer.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.494-501
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• 2020

When we develop an OpenGL-based coastline map that displays the high resolution data of GSHHG, it takes tens of seconds until the first scene is rendered. That is because it takes time to tessellate polygons with a huge number of vertices. A commonly used solution is that it converts original data to a customized data in advance, and it displays these. But if we should use original data to display a coastline map, we need to find another solution. In this paper we suggest using a polygon splitting technique to minimize tessellation time. In order to prove its effectiveness, we implemented a software applied this technique and measured its performance. The software applied this technique took a few seconds to display the first scene and we confirmed its effectiveness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.8
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• pp.1332-1338
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• 1997

In the case of the transfer function for the secondary path is dependent on time, the on-line method which can model it is continuously must be applied to the active noise control technique. And the adaptive random noise technique among the on-line methods is effective in the narrow-band control. In this method, the signal to noise ratio between random noise for modeling and primary noise is low. Therefore, the estimations of transfer function will be prone to inaccuracies and the convergence time will be too long. Such imperfections will have an influence upon the performance of an active noise controller. In this study, t enhance the signal to noise ratio, the on-line method that is combined the conventional adaptive random noise technique and the adaptive line enhancer, is proposed. By using proposed on-line method, a rigorous system identification and control of primary noise have been implemented.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.1
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• pp.113-121
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• 2020

PURPOSE: The study examined the effects of non-elastic taping on the knee and ankle joints of stroke patients to increase muscle activity, balance and gait ability. METHODS: In this study, 10 stroke patients were assigned to experimental group (knee and ankle joint non-elastic taping and PNF technique) and control group (PNF technique). The experimental group applied the PNF technique for 30 minutes after attaching the inelastic tape, and the control group performed the PNF technique for 30 minutes. five times a week for a total of four weeks (20 times). RESULTS: The muscle activity of Vastus Medialis and Tiblialis Anterior showed significant differences between the experimental and control groups. BBS and 10MWT also showed significant differences between the experimental and control groups. CONCLUSION: In this study, the muscle activity, balance and walking on the paraplegic side of stroke patients using inelastic taping, and applied inelastic taping on two joints in a different way from the previous study, Therefore, it will have the advantage of increasing paralysis side muscle activity and improving balance and walking ability.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.468-472
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• 2003

The lifting technique is a standard control procedure that is commonly applied to dual-rate systems, where a critical difficulty is that care must be taken so that the resulting equivalent system preserves the causality constraint between the control signal and the measured output. To overcome this difficulty, the most attractive result has been suggested by defining control time sequences as the union of sample and hold time sequences. However, the sacrifice of regular control period scheme results in some serious disadvantages; restrictions on the implementation to hardware and the corresponding inefficient control scheme. On the contrary, this paper proposes a novel dual-rate control technique, which redescribes the system as a control-rate-based system having regular control period and designs the controller, with no causality constraint, through Linear Matrix Inequality (LMI) formulation.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.4
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• pp.75-81
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• 2001

Fuzzy supervisory control method is studied for the active control of earthquake excited structures. The proposed algorithm supervises and tunes previously designed control gains by evaluating the state of a structure through the fuzzy inference mechanism, which uses the information of relative displacements and velocities. Example designs and numerical simulations of earthquake exited three degrees of freedom structures are performed to prove the validity of the proposed control algorithm. Comparative results with conventional LQR method show that the proposed method is effective for the vibration suppression of earthquake excited structures.