• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.183-185
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• 2006

This paper presents a SISO nonlinear controller for the power system consisting of a synchronous generator connected to an infinite bus. The proposed controller is based on input-output feedback linearization, with a modified version of the terminal voltage equation used as the output. The resulting closed-loop has no internal dynamics, and thus stability is guaranteed. The controller performance is seen to be effective through simulations.

• 대기
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• 제20권2호
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• pp.101-109
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• 2010

The service of health information was provided through internal and external weather agency web sites. The purpose of this study was to analyze current status of the weather agency web sites dealing with health information in the internet, and to evaluate their contents and technical aspects. The evaluation tool consisted of five area (appropriateness, accessibility, supportiveness, feedback, and continuance) with nineteen items. For the public confidence, web sites were limited to national meteorological administration and representative weather agencies. The evaluating web sites were fourteen from eight countries. The evaluation scores of fourteen web sites were 37.8 out of 53.0 in total. Each subcategory score were 5-12 out of 12 in appropriate, 4-12 out of 12 in accessibility, 4-10 out of 11 in supportiveness, 2-8 out of 9 in feedback, and 2-8 out of 9 in continuance. The score of feedback was the lowest. Survey results indicated that Korean Meteorological Administration homepage was middle status compared with the others in side of depth of health information and feedback from expert. Climate change affect human health, so it will be possible to prevent some disease at first through climate information. It should be developed to provide high quality health information and system related climate on KMA homepage.

• 전기전자학회논문지
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• 제24권4호
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• pp.1162-1166
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• 2020

본 논문에서는 피드백 감지 회로 구조로 인하여 향상된 load regulation 특성을 개선시킨 LDO를 제안하였다. LDO 레귤레이터 내부 오차증폭기의 출력단과 패스 트랜지스터의 입력단 사이에 제안된 feedback 감지 회로를 추가하여 출력에 들어오는 델타 값의 regulation을 개선시켜 기존의 LDO 레귤레이터보다 개선된 load Regulation 특성의 전압 값을 갖는다. 제안된 회로는 Cadence의 Spectre, Virtuoso 시뮬레이션을 이용하여 삼성 0.13um 공정에서 특성을 시뮬레이션 하였다.

• 대한물리의학회지
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• 제6권3호
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• pp.303-310
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• 2011

Purpose : This study examined the feedback effect of real-time ultrasound imaging on the thickness of transversus abdominis(TrA), internal abdominal oblique(IO) and external abdominal oblique(EO) during abdominal hollowing exercise(AHE) in crook lying. Methods : We performed this study on 30 healthy men who voluntarily consented to participate in this study after listening to its purpose and method. All subject were divided into an experimental group(n=15) with using the real-time ultrasound imaging feedback(RUIF) and a control group(n=15) without the RUIF The thickness changes between rest and AHE were compared between the two groups in crook lying. Results : The difference in TrA and EO thickness changes between the groups were significant in crook lying (p<0.05). Conclusion : The group with using real-time ultrasound imaging feedback showed a higher increase in the thickness of TrA than the other group without real-time ultrasound imaging feedback. And the thickness of EO in the group with using real-time ultrasound imaging feedback decreased than the other group without real-time ultrasound imaging feedback. If the muscle thickness can be regarded as an indicator of muscle activity, RUIF will be helpful for inducing the independent activity of TrA by reducing the activities of abdominal muscles such as EO.

• 한국소음진동공학회논문집
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• 제15권8호
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• pp.954-961
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• 2005

This paper is concerned with the implementation of auto-tuning positive position feedback controller using a digital signal processor and microcontroller. The main advantage of the positive position feedback controller is that it can control a natural mode of interest by tuning the filter frequency of the positive position feedback controller to the natural frequency of the target mode. However, the positive position feedback controller loses its advantage when mistuned. In this paper, the fast fourier transform algorithm is implemented on the microcontroller whereas the positive position feedback controller is implemented on the digital signal processor. After calculating the frequency which affects the vibrations of structure most, the result is transferred to the digital signal processor. The digital signal processor updates the information on the frequency to be controlled so that it can cope with both internal and external changes. The proposed scheme was installed and tested using a beam equipped with piezoceramic sensor and actuator. The experimental results show that the auto-tuning positive position feedback controller proposed in this paper can suppress vibrations even when the target structure undergoes structural change thus validating the approach.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.498-503
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• 2005

This paper is concerned with the implementation of adaptive positive position feedback controller using a digital signal processor and microcontroller The main advantage of the positive position feedback controller is that it can control a natural mode of interest by tuning the filter frequency of the positive position feedback controller to the natural frequency of the target mode. However, the positive position feedback controller loses its advantage when mistuned. In this paper, the fast fourier transform algorithm is implemented on the microcontroller whereas the positive position feedback controller is implemented on the digital signal processor. After calculating the frequency which affects the vibrations of structure most the result is transferred to the digital signal processor. The digital signal processor updates the information on the frequency to be controlled so that it can cope with both internal and external changes. The proposed scheme was installed and tested using a beam equipped with piezoceramic sensor and actuator. The experimental results show that the adaptive positive position feedback controller proposed in this paper can suppress vibrations even when the target structure undergoes structural change thus validating the approach.

• 대한물리의학회지
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• 제7권4호
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• pp.533-539
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• 2012

PURPOSE: The purpose of this study was to investigate the effect of pelvic floor muscle contraction with image feedback on Abdominal muscle thickness. METHODS: Twenty three adults participated in this study. Abdominal muscle thickness was measured by ultrasound in three condition(rest, pelvic floor muscle contraction, pelvic floor muscle contraction with image feedback). Subjects was contraction pelvic floor muscle by general method. And ultrasound(convex probe, 3.5MHz) was used to image feedback for selective pelvic floor muscle contraction. One-way ANOVA was used to compare abdominal muscle thickness in three condition. RESULTS: There was no significant difference in external oblique(p=.514) and internal oblique muscle(p=.250) thickness by three condition. There was significant difference in transverse abdominis thickness by three condition (Transverse abdominis thickness was highest while Pelvic floor muscle contraction than pelvic floor muscle contraction with image feedback and rest.)(p=.000). CONCLUSION: This study shows that pelvic floor muscle contraction with image feedback increase the thickness of transverse abdominis lesser than general pelvic floor muscle contraction.

• 한국운동역학회지
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• 제33권2호
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• pp.62-72
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• 2023

Objective: Although balance training has been used as an effective ankle injury rehabilitation program to restore neuromuscular deficits in patients with chronic ankle instability, it is not effectively used in terms of motor learning. Attentional focusing can be an effective method for improving ankle kinematics to prevent recurrent ankle injuries. This study aimed to 1) evaluate the effects of attentional focus, including internal and external focus, and 2) determine a more effective focusing method for patients with chronic ankle instability to learn balance tasks. Method: Twenty-four patients with chronic ankle instability were randomly assigned to three groups (external focus, internal focus, and no feedback) and underwent four weeks of progressive balance training. The three-dimensional ankle kinematics of each patient were measured before and after training as the main outcomes. Ensemble curve analysis, discrete point analysis, and post hoc pairwise comparisons were performed to identify interactions between groups and time. Results: The results showed that (1) the external focus group was more dorsiflexed and everted than the internal focus group; (2) the external focus group was more dorsiflexed than the no feedback group; and (3) the no feedback group was more dorsiflexed than the internal focus group. Conclusion: Because dorsiflexion and eversion are ankle motions that oppose the mechanism of lateral ankle sprain, using the external focus method during balance training may be more effective in modifying these motions, thereby reducing the risk of ankle sprain.

• The Journal of Korean Physical Therapy
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• 제22권6호
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• pp.1-6
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• 2010

Purpose: This study investigated the effects of visual feedback during abdominal hollowing (AH) in four point kneeling position, using real-time ultrasound imaging through measurement of the changes in the thickness of transversus abdominis (TrA), internal abdominal oblique (IO), and external abdominal oblique (EO). Methods: The subjects of this study were 32 healthy males who were divided intothe experimental group of 16 subjects and the control group of 16 subjects. The real-time ultrasound feedback was applied to the experimental group while they were educated on the AH exercise in four point kneeling whereas only general education and training were given to the control group. After the training, the changes in the thickness of abdominal muscles during AH in four point kneeling were compared between the experimental group and the control group. Results: The differences of the changes in the thickness of TrA and EO between the two groups were statistically significant. Conclusion: The experimental group experienced a higher increase in the thickness of TrA than the control group while the thickness of IO and EO of the experimental.

• 간호행정학회지
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• 제13권2호
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• pp.242-253
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• 2007

Purpose: The aim of this study is to examine the effectiveness of an computer-tailored intervention program to promote breast-feeding. Method: A quasi-experimental design was used assigning forty pregnant women to the experimental group (computer-tailored intervention condition) and the control group (no-intervention control condition). Thirty-three participants completed pretest and posttest questionnaires and 19 participants assigned to intervention condition received personal feedback tailored by computer program. Result: Participants in the experimental group showed higher mean score of 'perception of the importance of breast-feeding'. Significant differences in internal health locus of control was found between the participants in the experimental group and the control group. Participants in the experimental group exceeded controls on intention of breast-feeding. Participants in the control group more often felt that the length of program contents they received was somehow longer. Conclusions: The use of a computer-tailored intervention improved the perception of the importance of breast-feeding and the internal health locus of control. The intention of breast-feeding was increased through the personal feedback tailored by computer even though participants felt that the length of program contents of tailored feedback was not longer.