• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.417-423
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• 2002

Magnetorheological(MR) 댐퍼는 적은 용량의 전력을 사용하고 반응속도가 빠른 장점 때문에 구조물의 내진제어에 적당하여, 근래에 주목받고 있는 새로운 장치이다. MR 댐퍼는 반능동 제어 장치로써, 능동 질량감쇠기와는 다른 특성을 갖는다. 즉 필요한 제어력을 제어신호로 직접 생성해 낼 수 없는 대신에 MR 댐퍼의 입력전원을 제어하여 간접적으로 제어한다. 따라서 MR 댐퍼의 반능동 제어장치로써의 특성을 고려하는 효과적인 제어기법이 요구된다. 그러므로 본 연구에서는 지진에 대한 구조물의 응답을 줄이기 위해서, MR댐퍼를 제어할 수 있는 반능동 제어기법을 Lyapunov 안정성 이론을 바탕으로 제안하고자 한다. 제안방법을 검증하기 위해, 전단형 MR 댐퍼를 1층과 2층에 설치한 수치예제를 수행하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.62.3-62
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• 2001

The predictive control is one of the nonlinear three-axis rotation methods. The desired trace of a satellite is pre-determined, and the control inputs are designed so that the satellite follows the ´predictive´ trace. The predictive control has been adapted to the research for the three-axis attitude control. In that case, the control variables are the quaternion represented the angular rates and attitude angles of the body about the three-axes. The objective of this paper is to propose to design a predictive controller for the three-axis attitude control under external disturbances. In order to do that, this paper proposes how to construct a predictive control law including disturbances and to discern them. The basic algorithm of the existent predictive control is partially modified, and the presumption and modeling of disturbances are performed ...

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.439-443
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• 1987

This paper presents a method for constructing model of manufacturing processes for simulation and design of the discrete control logic. The models represent the discrete vent evolution of the system as well as features of the underlying continues processes, for applications such as discrete parts manufacture and assembly, the process is decomposed into operations and for each operation the required resources and associated discrete resource slates are Identified. The structure of the discrete-level control is modeled by modified Perti nets which are synthesized from single resource activity cycles. Construction of nets provides discrete control logic with guaranteed properties based on extended Petri nets theory, for illustration, the proposed method is applied to the high-level discrete control of a two-robotic assembly cell.

• Journal of Astronomy and Space Sciences
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• 제20권4호
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• pp.365-374
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• 2003

Satellite formation flying is currently an active area of research in the aerospace engineering. So it has been researched by various authors. In this study, a tracking controller using sliding mode techniques was designed to control a satellite for the satellite formation flying. In general, Hill's equations are used to describe the relative motion of the follower satellite with respect to the leader satellite. However the modified Hill's equations considering the $J_2$ perturbation were used for the design of sliding mode controller. The extended Kalman filter was applied to estimate the state vector based on the measurements of relative distance and velocity between two satellites. The simulation results show that the follower satellite tracks the desired trajectory well by thruster operations based on the sliding mode control law.

• PNF and Movement
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• 제11권2호
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• pp.41-48
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• 2013

Purpose : The aim of this study was to compare the effect of task-oriented training using the PNF(proprioceptive neuromuscular facilitation) and task-oriented training with chronic stroke patients. Methods : Sixteen chronic stroke patients participated. Participants were randomly assigned to the control and experimental group( 8 experimental, 8 control). All of participants were in-patients at local hospital and had been received training appropriate to the purpose of each group program. Experimental period was carried out 30 minutes/day, five days/week, during four weeks. The experimental group trained the task-oriented training using the PNF and control group trained the task-oriented training. Fugl-meyer assessment scale and Modified Barthel Index was measured to compare the upper arm function and activities of daily living. We were measured before and after the training. Results : The results of the study were as follow: Fugl-meyer assessment scale was significantly increased both groups(p<.05), and significant between groups(p<.05). Modified Barthel index was significantly increased both groups(p<.05) and between groups(p<.05). Conclusion : PNF can be effective in improving upper arm function and ability to perform daily life of chronic stroke patients.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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• pp.41-41
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• 2003

Satellite formation flying is currently an active area of research in the aerospace engineering. There are many categories for this research such as the determination of initial conditions, formation keeping, configuration and reconfiguration. In this study, a tracking controller using sliding mode techniques is designed to control a satellite for the satellite formation flying. In general, Hill's equations are used to describe the relative motion of the follower satellite with respect to the leader satellite. But, the modified Hill's equations considering J2 perturbation were used for the design of sliding mode controller. Sliding mode control law causes the chattering phenomenon because it is a discontinuous control. Dead-zone was used to avoid the chattering. The Extended Kalman filter was applied to estimate the state vector based on the measurements of relative distance and velocity between two satellites.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.430-433
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• 1989

This paper describes dynamic engine model that is appricable to idle speed control system development. A basic linear engine model responds to throttle and load torque Inputs to provide manifold pressure and speed outputs. Transfer functions are then derived for the modified linear engine model and significant dynamic characteristics are discussed. Lastly, the strategy for controlling idle speed uses the linear optimal control theory. The linear optimal regulator was designed using a state variable and the performance Index was minimized.

• 대한물리의학회지
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• 제8권2호
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• pp.245-252
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• 2013

PURPOSE: The aim of this study is to verify the effectiveness of modified constraint-induced movement therapy(mCIMT) on upper function and activities of daily living in people with subacute stroke patients. METHODS: Eighteen participants, with subacute stroke that were randomly assigned to either the experimental group(n=9) or the control group(n=9). For subjects from the experimental group modified Constraint-Induced Movement Therapy was performed. exercise program, the patient trained in affected side upper extremity with restricted non-affected side for 1 hour and using in activity daily living for 4 hours for five times per week, during 4 weeks. For subjects from the control group, conventional upper extremity training was performed. Outcomes such as the box and block test(BBT), Fugl-Meyer motor function assessment(FMA), and modified Barthel index(MBI) were measured before and after training. Between-group and within-group comparisons were analyzed by using Independent t-test and Paired t-test respectively. RESULTS: These finding suggest that experimental group was significant increase in BBT, FMA, MBI(p<.05). In comparison of two group, experimental group was high upper function and activity daily living than control group. CONCLUSION: This study showed experimental group can be used to improve upper function and activity daily living than control group. Thus it indicates that mCIMT will be more improved through the continued upper extremity exercise program.

• PNF and Movement
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• 제18권1호
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• pp.23-34
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• 2020

Purpose: To explore the effects of action observation combined with modified constraint-induced movement therapy on upper-extremity function and the activities of daily living in subacute stroke patients. Methods: Twenty-four subacute stroke patients were randomly assigned to the experimental group or the control group (n = 12 each). Both groups received therapy based on motor learning concepts, including repetitive and task-specific practice. The experimental group watched video clips for 10 minutes related to tasks performed during modified constraint-induced movement therapy while the control group watched videos unrelated to upper-extremity movement. These programs were performed for 40 minutes a day five times a week for four weeks. Their scores on the Fugl-Meyer assessment of upper extremities (FMA-UE), the action research arm test (ARAT), a motor activity log (amount of use [AOU] and quality of movement [QOM]), and the modified Barthel index (MBI) were recorded. Results: In both groups, all variables were significantly different between the pre-test and post-test periods (p < 0.05). The post-test variables were significantly different within each group (p < 0.05). In the experimental group, the changes between pre-test and post-test scores in the FMA-UE (14.39 ± 4.31 versus 6.31 ± 4.63), the ARAT (16.00 ± 4.73 versus 11.46 ± 3.73), MAL-AOU (1.57 ± 0.15 versus 1.18 ± 0.28), and MBI (27.54 ± 4.65 versus 18.08 ± 8.52) were significantly higher than those of the control group (p < 0.05). Conclusion: These findings suggest that action observation combined with modified constraint-induced movement therapy may be a beneficial rehabilitation option to improve upper-extremity function in subacute stroke patients with moderate impairment.

• International Journal of Aeronautical and Space Sciences
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• 제4권1호
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• pp.75-87
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• 2003

The primary objective of this study is to demonstrate ground-based experiment for the attitude control of spacecraft. A two-axis rotational simulator with a flexible ann is constructed with on-off air thrusters as actuators. The simulator is also equipped with payload pointing capability by simultaneous thruster and DC servo motor actuation. The azimuth angle is controlled by on-off thruster command while the payload elevation angle is controlled by a servo-motor. A thruster modulation technique PWM(Pulse Width Modulation) employing a time-optimal switching function plus integral error control is proposed. An optical camera is used for the purpose of pointing as well as on-board rate sensor calibration. Attitude control performance based upon the new closed-loop control law is demonstrated by ground experiment. The modified switching function turns out to be effective with improved pointing performance under external disturbance. The rate sensor calibration technique by Kalman Filter algorithm led to reduction of attitude error caused by the bias in the rate sensor output.