• 제목/요약/키워드: External Control

검색결과 3,209건 처리시간 0.034초

Adaptive Neural Dynamic Surface Control via $H_{\infty}$ Approach for Nonlinear Flight System (비선형 비행 시스템을 위한 $H_{\infty}$ 접근법 기반 적응 신경망 동적 표면 제어)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1728-1729
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    • 2007
  • This paper presents an adaptive neural dynamic surface control (DSC) approach with $H_{\infty}$ tracking performance for a full dynamics of a nonlinear flight system. It is assumed in this paper that model uncertainties such as structured and unstrutured uncertainties and external disturbances influence the nonlinear aircraft model. In our control system, self recurrent wavelet neural networks (SRWNNs) are used to compensate model uncertainties of the nonlinear flight system, and an adaptive DSC technique is extended for disturbance attenuation of the nonlinear flight system. From Lyapunov stability theorem, it is shown that $H_{\infty}$ performance from external disturbances can be obtained. Finally, we perform the simulation for the nonlinear six-degree-of-freedom F-16 aircraft model to confirm the effectiveness of the proposed control system.

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Sliding Mode Control of a Robot Manipulator by the Impedance Approach (임피던스 방식에 의한 로보트 매니퓰레이터의 슬라이딩 모드 제어)

  • 최형식
    • Journal of Advanced Marine Engineering and Technology
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    • 제18권4호
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    • pp.25-32
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    • 1994
  • This paper presents a robust impedance controller design to coordinate a robot manipulator under system uncertainties while regulating external forces. By an impedance approach, the relationship between the motion and external forces is defined. Due to the system uncertainties, two kind of sliding mode control schemes based on the impedance approach are derived to ensure that the manipulator end-effector follows a desired trajectory and the force applied to end effector is regulated according to a target impendance. A stability condition is shown according to a sliding condition. To evaluate the devised control scheme, a numerical example is shown.

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Implementation of Optimal Temperature Controller for Thermoelectric Device-based Heating System Using Genetic Algorithm (유전알고리즘을 이용한 열전소지 기반 히팅 시스템의 최적 온도 제어기 구현)

  • Jung-Shik Kong
    • Design & Manufacturing
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    • 제17권3호
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    • pp.41-47
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    • 2023
  • This paper presents the development of a controller that can control the temperature of an heating system based on a thermoelectric module. Temperature controller using Peltier has various external factors such as external temperature, characteristics of an aluminum plate, installation location of temperature sensors, and combination method between the aluminum plate and heating element. Therefore, it is difficult to apply the simulation and simulation results of heating system using Peltier at control algorithm. In general, almost temperature controller is using PID algorithm that finds control gain value heuristically. In this paper, it is proposed mathematical model that explain correlate between the temperature of the heating system and input voltage. And then, optimal parameter of estimated thermal model of the aluminum plate are searched by using genetic algorithm. In addition, based on this estimated model, the optimal PID control gain are inferred using a genetic algorithm. All of the sequence are simulated and verified with proposed real system.

A Second Order Sliding Mode Control of Container Cranes with Unknown Payloads and Sway Rates (미지의 부하와 흔들림 각속도를 갖는 컨테이너 크레인의 2차 슬라이딩 모드 제어)

  • Baek, Woon-Bo
    • Journal of Institute of Control, Robotics and Systems
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    • 제21권2호
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    • pp.145-149
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    • 2015
  • This paper introduces a sway suppression control for container cranes with unknown payloads and sway rates. With no priori knowledge concerning the magnitude of payload mass and sway rate, the proposed control maintains superior sway suppressing and trolley positioning against external disturbances. The proposed scheme combines a second order sliding mode control and an adaptive control to cope with unknown payloads. A second order sliding mode control without feedback of the sway rate is first designed, which is based on a class of feedback linearization methods for stabilization of the under-actuated sway dynamics of the container. Under applicable restrictions of the magnitude of payload inertia and sway rate, a linear regression model is obtained, and an adaptive control with a payload estimator is then designed, which is based on Lyapunov stability methods for the fast attenuation of trolley oscillations in the vicinity of the target position. The asymptotic stability of the overall closed-loop system is assured irrespective of variations of rope length. Simulation are shown in the existence of initial sway and external wind disturbances.

The Effect of External-rotation Reducing Exercise on the Gait of Patient with Hemiplegia (편마비 환자의 보행에 대한 외회전 감소운동의 효과)

  • Kim, Ah-Ram;Park, Cheol-Ju;Ryu, In-Jeong;Choi, Jeong-Wook;Hyun, Ju-Hyup;Cho, Nam-Jung;Yoo, Byung-Kook;Jeong, Jong-Hee;Lee, Ho-Jun
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • 제6권1호
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    • pp.69-79
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    • 2008
  • In this paper, the effects of the external-rotation exercise on the gait of hemiplegia was investigated. 26 patients with hemiplegia due to cerebrovascular accident participated in this study. Subjects were randomly assigned to experimental group(n=12) and control one(n=14). 12 subjects of the experimental group were received the external rotation reducing exercise on the mat with seating and supine posture after the general therapeutic exercise for hemiplegia. 14 subjects of the control group were received only general therapeutic exercise. The effects of external rotation reducing exercise were evaluated by measurements of gait velocity, cadence, stride length, step length and foot angle using ink-foot prints. The collected data were analyzed statistically based on Wilcoxon, Mann-Whitney and correlation analysis. After treatment of three weeks, it turned out that external rotation reducing exercise has the significant effect on foot angle(p<0.01). However the exercise has no statistically significant direct effect on the gait velocity, cadence, stride length and step length.

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The Effect of Attentional Focus on Performance of Task (집중방식이 과제수행에 미치는 영향)

  • Roh, Jung-Suk;Kim, Jang-Hwan
    • Journal of Korean Physical Therapy Science
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    • 제13권3호
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    • pp.77-84
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    • 2006
  • The purpose of this study is to introduce the effect of attentional focus on performance of task. Previous studies has shown that motor learning can be enhanced by directing performers's attention to the effects of their movements(external focus), rather than to the body movement producing the effects(internal focus). Wulf and colleagues have invoked the 'constrained action hypothesis' to explain the comparative benefits of adopting an external rather than an internal focus of attention. This hypothesis proposed that when performers utilize an internal focus of attention, they may actually constrain or interfere with automatic control processes that would normally regulate the movement, whereas an external focus of attention allows the motor system to more naturally self-organize. Electromyography(EMG) was used to determine neuromuscular correlates of external versus internal focus differences. EMG activity was lower with an external relative to an internal focus. This suggest that an external focus of attention enhances movement economy, and presumably reduces 'noise' in the motor system that hampers fine movement control. Focusing on a more remote effect seems to facilitate the discriminability of the effect from the body movements that produced it and to be more beneficial than focusing on a very close effects. There might be an optimal distance of the effect, at which ti wis easily distinguishable from the body movement but at which it is also still possible for the performer to relate this effect to the movement techniques. Future Studies of motor learning of patient need to accommodate these new finding and account for the role of the learner's attentional focus and its influencing on learning.

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Successful local use of heparin calcium for congested fingertip replants

  • Kadota, Hideki;Imaizumi, Atsushi;Ishida, Kunihiro;Sashida, Yasunori
    • Archives of Plastic Surgery
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    • 제47권1호
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    • pp.54-61
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    • 2020
  • Background Conventional methods of external bleeding for congested fingertip replants exhibit notable problems, including uncontrollable bleeding and unpredictable survival of the replant. We have added a local injection of heparin calcium to the routine use of systemic heparinization for inducing external bleeding. We retrospectively examined patients who underwent external bleeding using our method. Methods Local subcutaneous injections of heparin calcium were made in 15 congested replants in addition to systemic heparinization. Each injection ranged from 500 to 5,000 U. The average duration of the injections was 4.1 days. Surgical outcomes were analyzed and compared with a control group of patients who underwent external bleeding without heparin calcium. Results The overall survival rate was 93.3%, which was higher than that of the control group (83.3%), but the difference was not statistically significant (P=0.569). The survival rate for subzones I and II by the Ishikawa subzone classification was 100%, whereas it was 87.5% in subzones III and IV. No statistically significant difference was observed. The rate of partial necrosis was 0% in subzones I and II, whereas it was significantly higher (66.7%) in subzones III and IV (P=0.015). The mean total blood loss via external bleeding was 588 g in 10 fingers. No patients required blood transfusion. Conclusions Congestion of a replanted fingertip can be successfully managed without blood transfusion by our method. Although complete relief from congestion in replants in subzones I and II is achievable, there is a higher risk of partial necrosis in subzones III and IV.

A Development of Risk-Taking Behavior Forecasting Model of Taxi driver's Risk-Taking Propensity by Structural Analysis (택시운수업 종사자 위험성향 관련 변인들의 구조적 분석을 통한 위험감행 예측 모형 개발)

  • Park, Mi So;Yoon, Hyo Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • 제32권4D호
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    • pp.313-322
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    • 2012
  • This study analyzes taxi driver's risk-taking propensity with respect to risk-taking behaviour and traffic locus of control. In order to explore the traffic risk-taking, we present a predictive model by structural analysis of driver's risk-taking propensity. By applying this model to survey data from taxi drivers, we can observe that driver's risk-taking propensity has a significant impact on the traffic violation intention, and the higher perception of law and the lower lack of law-abiding drivers have, the more they tend to violate. Second, we test using multivariate analysis if the level of risk-taking propensity differs by the locus of control( external or internal). Drivers of external control shows higher risk-taking level compared to those of internal control so that the risk-taking propensity shows difference according to the locus of control for the responsibility of traffic accidents. The structural equation model of our study yielded ${\chi}^2$ = 279.7, ${\chi}^2$/df = 1.55, RMSEA = 0.44, GFI = 0.911, TLI = 0.916, CFI = 0.929.

Effects of Sopoongsangagambang Administration along with External Spray Treatment on Atopic Dermatitis Development in NC/Nga Mice (소풍산가감방(消風散加減方)과 외치방(外治方) 병용이 NC/Nga 아토피 생쥐에 미치는 영향)

  • Min, Young-Gyu;Kim, Jong-Han;Park, Su-Yeon;Choi, Jung-Hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • 제18권1호
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    • pp.116-134
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    • 2005
  • Although the parallel prescription of Sopoongsangagambang (SG) administration along with external treatment such as spraying or ointment application on the skin is clinically used for the treatment of atopic dermatitis (AD), molecular mechanism underlying its effectiveness is unknown. Thus in the present study, diverse immune responses in terms of chemical mediators related to AD were investigated using an atopic mouse model NC/Nga after SG administration and external treatment (ET), and major findings are summarized as follows. 1. The clinical severities in 16 and 20 week old NC/Nga mice with SG and ET treatment were decreased to 72.2% and 62.3% respectively compared to the control NC/Nga mice with no drug treatment. 2. IgE, IL-4, IL-5, IL-6, IL-13, IgM, IgG1 and IgG2a levels in the serum of SG and ET treated NC/Nga mouse group were significantly decreased compared to the untreated control mice. In contrast, $IFN-{\gamma}$ showed a significant increase in the experimental group compared to the untreated control group. 3. The spleen weight of SG and ET treated NC/Nga mice was significantly decreased compared to the untreated control group. 4. The B/T ratio in the lymph node of SG and ET treated NC/Nga mice was increased compared to the untreated control group. $CD4^+\;and\;CD8^+$ cell numbers in the lymph node of SG and ET treated NC/Nga mice were significantly increased compared to the untreated control group, but $CD69^+\;and\;CD11a^+$ cells were significantly decreased. 5. mRNA expression levels of IL-4, IL-5, and CCR3 in the skin tissues of SG and ET treated NC/Nga mice were significantly decreased, and expression levels of IL-6, IL-13, $CD69^+/CD3{\varepsilon}^+\;and\;CD19^+/CD44^+$ in the skin tissues of SG and ET treated NC/Mga mice were significantly decreased compared to the untreated control group. $IFN-{\gamma}$ mRNA expression levels were increased compared to the untreated control group. 6. Histological observation of the ear and neck skin tissues showed that the extents of inflammation and infiltrated immune cells in the epidermis and dermis of SG and ET treated NC/Nga mice were highly reduced compared to the untreated control group. 7. Lymphokine assay showed a significant decrease in IL-4 levels in SG and ET treated NC/Nga mice compared to the untreated control group, but the levels of $IFN-{\gamma}$ secretion were significantly increased drug treated NC/Nga mice.

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A Relations of Bone Mass Promoting Behaviors for Prevention of Osteoporosis and Multidimensional Health Locus of Control Scale Cluster (골다공증 예방을 위한 골량증진행위와 건강통제위 유형과의 관계)

  • Yeoum, Soon-Gyo
    • Women's Health Nursing
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    • 제3권2호
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    • pp.208-223
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    • 1997
  • This study was made to suggest the nursing strategies for promoting the behaviors about bone mass health behaviors in order to prevent middle aged women's osteoporosis. This study was a descriptive-correlational design that also concerned to the types which improve bone mass promoting behaviors by inspecting patterns of health locus of control method out of recognizable variables of health improving models influencing on these bone mass promoting behaviors. For these purpose, data were collected by self reported questionnaire in middle school, from 158 women living in Seoul. The measuring tools used in this study about bone mass promoting behaviors and multidimensional health locus of control, were developed by author on the basis of literature review and analyzed by SPSS-PC window, into pearson's correlation, ANOVA, multiple regression, cluster analysis. Data was analyzed as follows. 1. 6 Multidimensional health locus of control scale clusters were existed. : a)cluster I (pure internal), b)cluster II(pure chance), c) cluster III(Believer in control), d), cluster IV(Type VI), e)cluster V(yea sayer), f) cluster VI(nay sayer). There were no findings of the powerful others external cluster and double external cluster. 2. The higher the value of internal health locus of control was, the better the bone mass promoting behaviors were(r=.2891, $p=.00^{**}$). The higher the value of chance external health locus of control was, the worse the bone mass promoting behaviors were(r=-.1367, $p=.00^{**}$). 3. On the basis of these relationships, 6 clusters were significantly different in the bone mass promoting behaviors(F=2.27, $p=.05^*$). The value of bone mass promoting behaviors was ranked the order of type VI>believer in control>pure internal>yea sayer>nay sayer>pure chance external highly. 4. Bone mass promoting behaviors were not significantly different as to age. Suggestion. Based on the results from the study, I would like to make some suggestions as follows. 1) To delay the loss of bone mass in middle aged women, the study on the cluster of the multidimensional health locus of control should be conducted repeatedly. 2) The tool of multidimensional health locus of control should be developed through a qualitative method adjusted on Korean' health culture.

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