• Title/Summary/Keyword: external control

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A Study on Controlling the External Effect in Student Evaluation of Teaching

  • Lee S. W.;Lee K. H.
    • Communications for Statistical Applications and Methods
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    • v.12 no.3
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    • pp.589-601
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    • 2005
  • Student evaluation of university teaching is a common tool for measuring the educational contribution of a professor and improving the quality of classes. There, however, exist external factors in the beyond of control of a instructor, which affect the result of Student's rating to prevent practical use of evaluation for administrative purpose. This paper investigates the factors that spoil the validity and the reliability of student evaluation and proposes a method to control the effect by the statistical analysis of evaluation data of Jeonju University for two years.

Robust Reduced Order State Observer for Lipschitz Nonlinear Systems (Lipschitz 비선형 시스템의 강인 저차 상태 관측기)

  • Lee, Sung-Ryul
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.837-841
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    • 2008
  • This paper presents a robust reduced order state observer for a class of Lipschitz nonlinear systems with external disturbance. Sufficient conditions on the existence of the proposed observer are characterized by linear matrix inequalities. It is also shown that the proposed observer design can reduce the effect on the estimation error of external disturbance up to the prescribed level. Finally, a numerical example is provided to verify the proposed design method.

Synthesis on External Feedback Loop of Oculomotor Control System (안구제어계의 외부귀환 루우프 구성)

  • 박상희;김성환
    • 전기의세계
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    • v.26 no.4
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    • pp.54-60
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    • 1977
  • The feedback sources of oculomotor control system consist of three types of feedback path originating from retinal image displacement, in the proprioceptive fibers of the extraocular muscles, in the efference copy within the C.N.S. From above feedback loops, the retinal image feedback path is a main subject in this experiment. The electrical output of eye ball motion detecting with a photo-electric matrix method is fed into galvanometer through the external feedback path, and the stability was also examined.

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Remote Monitoring Systems Using StrongARM (StrongARM을 이용한 원격 감시시스템)

  • 임홍식;남현도;강철구
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2003.11a
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    • pp.259-264
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    • 2003
  • In this paper, web based monitoring systems are implemented using embedded Linux. The external equipment is controlled via HTTP protocol and web browser program. HTTP protocol is ported into Linux. A micro web server program and external equipment control program are installed on-board memory using CGI to be accessed by web browser. Experimental result of the proposed web based monitoring systems can be used in automation systems and remote distributed control via internet using web browser.

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Health Locus of Control and Eating Behavior of Obese High School Girls (비만 여고생의 건강통제위 성격과 섭식행동)

  • 문선영;김신정;김숙영
    • Journal of Korean Academy of Nursing
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    • v.31 no.1
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    • pp.43-54
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    • 2001
  • The purpose of this study was to investigate the relationship between health locus of control (HLOC) and the eating behaviors in obese high school girls. The sample consisted of 262 obese high school girls in Seoul and Kangwon-Do. The results of this study were as follows: 1. The average scores of HLOC were HLOC- Internal; 4.06, HLOC-External; 2.47, and HLOC-Chance; 2.15. 2. The average scores of eating behavior factors were Disinhibition ; 2.91, Hunger ; 2.73, Dietary Restraint ; 2.55. 3. The HLOC-Internal and eating behavior (dietary restraint, disinhibition and hunger) were correlated positively. The HLOC- Chance and hunger was correlated positively. But HLOC-Chance and other eating behavior factors (dietary restraint & disinhibition) were not correlated in the level of statistical significances. The HLOC-External and eating behavior (dietary restraint, disinhibition and hunger) were correlated positively. 4. There was not a significant difference in HLOC depending on the existence of an obese sibling. There were significant differences in HLOC-Internal and HLOC- External depending on the evaluation of one's body figure. 5. There were significant differences in disinhibition and hunger depending on the existence of obese sibling. Also, there were significant difference in dietary restraint according to self perception of who is obese or not (t=3.342, p=.001). This study has shown a correlation between HLOC and eating behavior. As a result of these findings, clinical and school nurses should be involved in management and counselling obese girls concerning individual health locus of control and eating behavior.

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Synchronous Control of an Asymmetrical Dual Redundant EHA (비대칭 이중화 EHA의 동기 제어)

  • Lee, Seong Ryeol;Hong, Yeh Sun
    • Journal of Drive and Control
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    • v.13 no.2
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    • pp.1-9
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    • 2016
  • In this paper, an elementary force fighting problem was investigated. The problem is encountered when a double-rod type EHA(electro-hydrostatic actuator) is combined with a single-rod type EHA to build a redundant actuator system with synchronized motion. When the rod-side chambers of the two different types of EHAs have the same effective piston areas and are simultaneously pressurized by an external load, the two EHAs behave identically, sharing the external load equally. However, when the piston head-side chamber of the single rod type EHA, having a larger effective area than the rod-side chamber, is pressurized by the external load, an abnormal force fighting between the two EHAs occurs, unless their pump speeds are properly decoupled. In this study, the output drive forces of each EHA were obtained from the cylinder pressure signals and applied to the position control for each EHA to maintain the balance between their pump speeds. Adding minor force difference feedback loops to the position control, the force fighting phenomena could be eliminated and steady state synchronization errors were reduced. The power consumption of the pumps also could be remarkably reduced, avoiding unnecessarily high load pressures to the pumps.

The Effect of Eccentric Strengthening Exercise on Athletes after Shoulder Rotator Cuff Tear (운동선수들의 견관절 회전근 손상 이후 등속성 측정을 통한 원심성 근력운동의 효과)

  • Kim, Jwa-Jun;Kim, Dae-Kyeong;Ha, Kyung-Jin
    • PNF and Movement
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    • v.12 no.1
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    • pp.33-37
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    • 2014
  • Purpose: In this research, the properties of the shoulder joint were measured through eccentric resistive exercise with the patients who have rotator cuff tear of shoulder joints as the targets. Methods: 23 patients who have pain due to the rupture of rotator cuff on shoulder joints were selected and divided into Exercise group (12) and Control group (11). Two groups executed exercise for 30 minutes 3 days a week. Exercise group had executed eccentric resistive exercise, and the Control group executed Complex exercise. Results: In external rotation $180^{\circ}/s$, $240^{\circ}/s$, the Exercise group showed to be an average of 8% higher than the Control group. For Internal rotation $90^{\circ}/s$, $180^{\circ}/s$, $240^{\circ}/s$ the Exercise group showed to be an average of 30% higher that the Control group. Conclusion: To lessen the rupture of rotator cuff on shoulder joints, muscles strengthening is very important across various methods of eccentric exercise programs which are external/internal rotators of the shoulder joint needed for throwing. This is effective in preventing injury and improving rotation.

Effect of Virtual Reality Based Ring Fit Adventure Core Exercise on the Thickness of the Transverse Abdominis, Internal Oblique and External Oblique Muscle (가상현실 기반의 링 피트 어드벤처 코어 운동이 배가로근, 배속빗근, 배바깥빗근의 두께에 미치는 영향)

  • Yoon, Sam-Won;Yoon, Sung-Young;Park, Han-Kyu
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.4
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    • pp.93-102
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    • 2022
  • Purpose : The purpose of this study was to analyze the change in thickness of transvers abdominis, internal oblique, and external oblique when virtual reality based ring fit adventure is applied to young adults in order to investigate the effect of ring fit adventure on core stabilization. Methods : 30 subjects participated in the experiment. Subjects were randomly assigned to two groups. 15 subjects performed ring fit adventure core exercise (experimental group) and 15 subjects bridge and dead bug exercise (control group). The ring fit adventure core exercise program consists of 6 types, 1) bow pull, 2) overhead lunge twist, 3) pendulum bend, 4) seated ring raise, 5) plank, 6) warrior III pose. Each exercise was performed for 5 minutes, for a total of 30 minutes. The bridege and dead bug exercise were performed for 15 minutes each for a total of 30 minutes. All interventions were performed 3 times a week for 4 weeks. Thickness of the abdominal muscles was measured with a ultrasound. The paired t-test was used to compare the thickness of the transverse abdominis, internal oblique, and external oblique before and after intervention, and the comparison between groups was analyzed using the independent t-test. Results : As a result, in the experimental group, thickness of transverse abdominis and internal oblique increased significantly (p<.05), but external oblique decreased significantly (p<.05), and in the control group, thickness of transverse abdominis, internal oblique, and external oblique increased significantly (p<.05). There was a significant difference in external oblique in the difference between groups (p<.05). Conclusion : These study results showed that core exercise using ring fit adventure can reduce external oblique and increased selective muscle activity of transverse abdominis and internal oblique of the deep abdominal muscles, so it is meaningful as an effective intervention for core stabilization.

Drawing and Writing as Methods to Assist Students in Connecting and Integrating External Representations in Learning the Particulate Nature of Matter with Multiple Representations (물질의 입자적 성질에 대한 다중 표상 학습에서 외적 표상들 간의 연계와 통합을 촉진시키는 방안으로서의 그리기와 쓰기)

  • Kang, Hun-Sik;Kim, Bo-Kyung;Noh, Tae-Hee
    • Journal of The Korean Association For Science Education
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    • v.25 no.4
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    • pp.533-540
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    • 2005
  • This study investigated the effects of drawing and writing as methods to assist students in connecting and integrating multiple external representations provided in learning the particulate nature of matter. Seventh graders (N=224) at a coed middle school were assigned to a control group, a drawing group, and a writing group. The students were taught about "Boyle's Law" and "Charles's Law" for two class periods. Students observed macroscopic phenomena through experiments. After this observation, students in the control group learned the topic with both external visual and verbal representations simultaneously. Students in the drawing group drew their mental model from the external verbal representation provided, and then compared their drawing with external visual representation. Students in the writing group wrote their mental model from the external visual representation provided, and then compared their writing to the external verbal representation. The two-way ANCOVA results revealed that the scores of a conception test for the writing group were significantly higher than those for the control group. While the drawing group performed better than the control group, the difference is relatively smaller. There were no significant interactions between the instruction and spatial visualization ability in the scores of the conception test. Most students perceived the writing or drawing activities helpful in understanding the concepts, and a few students responded that the writing or drawing activity was interesting. Educational implications were discussed.

Flutter Characteristics and Active Vibration Control of Aircraft Wing with External Store (외부장착물이 있는 항공기 날개의 플러터 특성 및 능동 진동 제어)

  • Kang, Lae-Hyong;Lee, Seung-Jun;Lee, In;Han, Jae-Hung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.4
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    • pp.73-80
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    • 2007
  • Modern aircraft are required to carry various external stores mounted at different locations on the wing. Sometimes the attachment of stores to an aircraft wing leads to flutter speed reduction, which is a very severe aeroelastic problem. In order to suppress structural vibration and expand the flutter boundary of the aircraft with stores, it is necessary to investigate the main problems and characteristics of them. In addition, active vibration control may be required because passive vibration isolators show limited capabilities for the various wing/store configuration. In this paper, therefore, the flutter stability to the various wing/store configurations was investigated and active vibration control of wing/store model was performed using a piezoelectric actuator.