• 한국과학교육학회지
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• 제15권1호
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• pp.17-26
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• 1995

The purposes of this study were to investigate the effects of systematic analogy on pupils' concepts changes compared with non-systematic analogy and no analogy using longuitudal study. The subjects were the second year middle school students(N=140), 49 of them were experimental group, using systematic analogy; 47 of them were control group 1, using non-systematic analogy; and 44 of them were control group 2, using no analogy. We have elicited their ideas about electric current three times: pretest, posttest and delayed posttest by P-O-E(Prediction-Observation-Explanation) method. With time, resistant ;rrelevant idea was decreasing dominantly; sequential reasoning idea and scientific idea were increasing; and current consumption idea was rare. Systematic analogy is more effective than non-systematic analogy on pupils' concepts changes of electric current. Systematic analogy is more effective than no analogy in case of simple situation, but we couldn't find significant difference between systematic analogy and no analogy in case of complicated situation.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.452-457
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• 1999

The recent control system has been changed into the type of PLC(Programmable Logic Controller) control. Up to now, systematic approach of PLC programming or control logic design is not suggested. In this study, the design process of the control logic is systematized and concrete process in each step is suggested. This systematized approach lead developer to be convenient to implement control system. When some error is occurred in the system, this approach enable the developer to analyze the reason of error rapidly and the system is amended according to systematic information of the analysis. The example of control system implementation following this approach is introduced.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1072-1075
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• 1993

To design a fuzzy controller for DC servo-motor, a systematic procedure is proposed. Fuzzy rule base is simply designed through utilizing both the PID gain and the pole-zero cancelation. The results of simulation show that the control system has good performances.

• 한국임상약학회지
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• 제33권4호
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• pp.221-241
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• 2023

Background: The purpose of this systematic review was to investigate the effects of digital therapeutics for insomnia on sleep disorders and mental health improvement compared to the control group. Methods: Following the guidelines on systematic review(PRISMA, NECA), a literature search was conducted through PubMed, Cochrane Library, EMBASE, RISS, KISS, and KoreaMed using keywords. The Cochrane Risk of Bias Tool and Review Manager version 5.3 were used for risk of bias and effect size assessment. Results: Thirty eight RCT met criteria for inclusion. When compared against three control conditions, the digital therapeutics for insomnia was an effective intervention for improvement sleep disorders and mental health in comparison to waiting list and Patient-directed care with some intervention by medical staff. However, digital therapeutics for insomnia were no more effective than face-to-face CBT-I control group. Conclusion: The efficacy of digital therapeutics for insomnia was evaluated differently depending on the control group. Therefore, in phase 3 clinical trials for efficacy evaluation, it is necessary to review whether the control group has been properly established.

• 중환자간호학회지
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• 제5권2호
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• pp.28-36
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• 2012

Purpose: The purpose of this study was to examine the effects of the systematic breathing exercise program on recovery of patients with pneumothorax. Methods: An nonequivalent interrupted time-series control group posttest design was used. Participants were 40 inpatients (Experimental Group; 20, Control Group; 20) at the one University Hospital in U city. The systematic breathing exercise program including education on deep breathing exercise using incentive spirometry, Range of motion (ROM) exercise in shoulder joint, walking exercise and feedback were provided to the experimental group, while the control group carried out deep breathing exercise using incentive spirometry. The duration of chest tube insertion, duration of hospitalization, and frequency of analgesics use were measured. The data were analysed by a SPSS/WIN program. Results: The duration of chest tube insertion and duration of hospitalization in the experimental group were significantly shorter than the control group. However, there is no difference of the frequency of analgesics use between the experimental group and control group. Conclusion: The result showed that the systematic breathing exercise program was effective to improve recovery of patients with pneumothorax. This program can be applied in hospitals for patients with pneumothorax as one of the nursing intervention modalities.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.389-392
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• 1996

We propose a method to improve repeatability positioning precision of a linear pulse motor. By using this method the systematic error which may make the precision worse can be suppressed easily. And also we show that Power OP-Amp drive system enables the accidental error to be suppressed in comparison with PWM control drive system using IGBT inverter. As a result of the suppression of systematic and accidental error, improved performance of a linear pulse motor with repetitive positioning control is shown by experimental results.

• International Journal of Precision Engineering and Manufacturing
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• 제9권4호
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• pp.39-44
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• 2008

In this paper, through the study of discrete implementation of time delay control (TDC) and PID control algorithm, a new systematic gain selection method for PID controller is proposed. An important advantage of this method is that it may be applied to real systems with very simple and systematic procedure. The proposed method is derived for SISO systems and then extended to MIMO system. Through simulation for the second order non-linear plant and experiment on 2-DOF robot, the effectiveness of the proposed method is confirmed. The proposed method could solve the problem of difficulty in gain tuning of existing PID controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.324-326
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• 2006

This paper present backstepping control approach for controling chaotic Liu system. The proposed method is a systematic design approach and consists in a recursive procedure that interlaces the choice of a Lyapunov Function. Based on Lyapunov stability theory, control laws are derived. We used the same technique to enable stabilization of chaotic motion to a steady state as well as tracking of any desired trajectory to be achieved in a systematic way. Numerical solution are shown to verify the result.

• Journal of Power Electronics
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• 제13권3호
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• pp.447-457
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• 2013

For grid-connected LCL-filtered inverters, resonance yields instability and low bandwidth. As a result, careful designs are required. This paper presents a systematic current control structure, where pole assignment consisting of one or more feedbacks is the inner loop, and the outer loop is the direct grid current control. Several other issues are discussed, such as the inner-loop feedback choices, pole-assignment algorithms, robustness and harmonic rejection. Generally, this kind of strategy has three different types according to the inner-loop feedback choices. Among them, a novel pole-assignment algorithm has been proposed, where the inner control maintains four freely-assigned poles which are just two pairs of conjugated poles located at the fundamental and resonance frequencies separately. It has been found that with the different types, the steady-state and dynamic performances are quite different. Finally, simulations and experiments have been provided to verify the control and design of the proposed methods.

• 동력기계공학회지
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• 제22권1호
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• pp.18-24
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• 2018

This paper focuses on systematic design about the membership ranges of the main design factors such as control error, control error rate, and sampling time for the fuzzy logic control of the variable speed drive refrigeration cycle. The upper and the lowest limit of the membership ranges are set up from the data of static characteristics obtained by experiments. Three kinds of membership ranges on the control error and the control error rate are tested by experiments. Especially, an effect of sampling time on control performance is also investigated in the same way. Experimental data showed the control error rate and the sampling time strongly effected on the control performance of the refrigeration cycle with a variable speed drive.