• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1461-1467
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• 2001

This paper proposes a new approach for the ant-swing control of overhead cranes. The proposed control consists of a model-based anti-swing control scheme and a practical path planning scheme. The anti-swing control scheme is designed based on the Lyapunov stability theorem; the proposed control does not require the usual constraints of small load mass, small load swing, slow hoisting speed, and small hoisting distance, but guarantees asymptotic stability while keeping all internal signals bounded. The path planning scheme is designed based on the concepts of minimum-time control and anti-swing control; the proposed path planning generates near-minimum-time trajectories independently of hoisting speed and distance. The effectiveness of the proposed control is shown by computer simulation.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.75-77
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• 2002

Stability theorem for nonlinear systems with slowly varying inputs is extended to systems with slowly varying and small jump inputs.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.103-111
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• 2016

This paper presents an adaptive variable weights tuning system for an integrated chassis control with electronic stability control (ESC) and active front steering (AFS) for lateral stability enhancement. After calculating the control yaw moment needed to stabilize a vehicle with a controller design method, it is distributed into the tire forces generated by ESC and AFS using weighted pseudo-inverse-based control allocation (WPCA). On a low friction road, lateral stability can deteriorate due to high vehicle speed. To cope with the problem, adaptive tuning rules on variable weights of the WPCA are proposed. To check the effectiveness of the proposed method, a simulation was performed on the vehicle simulation package, CarSim.

• Journal of the Korean Mathematical Society
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• v.32 no.4
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• pp.869-876
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• 1995

Piezo devices such as piezoceramic patches knwon as collocated rate sensor and actuators are commonly used in control of flexible structure (see, e.g., [1]) and noise reduction. Recently, Ito and Kang ([4]) developed a nonlinear feedback control synthesis for regulating fluid flow using these devices.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.463-467
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• 1991

A continuous variable structure system control as a DC servomotor trackhig controller is proposed for the improvement of the chattering problems. The stability property of the proposed algorithms is analyzed. The prescribed trackfiig error is gauranteed in the existence of load variations based on the stability analysis.

• The Journal of Korean Physical Therapy
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• v.24 no.6
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• pp.419-422
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• 2012

Purpose: Malalignment of the lower limbs may increases the difficulty of maintaining equilibrium. The purpose of this study was to study the effects of genu varum and poor posture in the sagittal plane on postural stability. Methods: We had 27 subjects with varus and 27 normal subjects participate in this study. Subjects for whom the distance between the medial epicondyles in the knee joint was more than 3 cm were classified as varus group, and subjects for whom the distance was less than 3 cm were classified as normal group. The measurements of static and dynamic stability were used overall stability index (OSI), anterioposterior stability index (APSI), and mediolateral stability index (MLSI) using a Biodex balance system. Results: When measuring the static stability index, there were significant differences in the mediolateral stability index between the varus and control groups. When measuring the dynamic stability index, there were significant differences in the overall, anteriorposterior, and mediolateral stability index between the varus and control groups. These results demonstrated that genu varum affects mediolateral movement in static stability, and overall, anterioposterior and mediolateral movements in dynamic stability. Conclusion: As genu varum affects static and dynamic stability in young adults, it increases the risk of injuries or falls. Exercise and surgery are required for realigning the genu varum. Future studies about postural stability in young children and elderly people who have a risk of falls due to lower postural control ability, are needed, as well as in young adults.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.101-108
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• 2010

Recently, core and neuromuscular training(CNT) is emerging as a clinically relevant tool to improve neuromuscular control and to prevent sports injuries. The purpose of this study was to examine the effect of a 12 weeks CNT program on the dynamic stability after drop landing. The subjects attempted drop landing onto the force platform on single foot from a 40 cm height distance. The collected data was used to calculate the dynamic stability index. The Dynamic stability index was derived by measuring the medial-lateral stability index(MLSI), anterior-posterior stability index(APSI), and the vertical stability index(VSI). In comparison to the control group, the MLSI and APSI showed no difference, yet, it resulted in higher VSI. The results of this study suggest that CNT is worthwhile to be considered as a way to improve neuromuscular control and to prevent traumatic injuries. However, the results are taking into consideration to discuss the limitations of CNT and suggested future approaches.

• Journal of Korean Physical Therapy Science
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• v.19 no.2
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• pp.63-71
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• 2012

Purpose : This study aimed to acquire a basic knowledge about lumbar stability and inquire into exercise approach of pressure biofeedback unit for lumbar stability. Methods : This study was composed with reviewed theory of lumbar stability and several books and articles for exercise using pressure biofeedback unit. Results : The stability of lumbar should work symmetrical with passive, active, control subsystem in neutral zone, and local muscles should be using for stability. Especially, selective using of transverse abdominis work for lumbar stability importantly. The control of using pressure biofeedback unit may important not only examination but treatment. Conclusion : The stability of lumbar need co-contraction of specific local muscle and training for timing as well as using pressure biofeedback unit for accurate control may use for examination and therapedic approach.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2863-2866
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• 2003

In nonlinear control fields, for irregular nonlinear systems, control form which consists of approximate tracking control law and exact tracking control law and which switches between two laws has been proposed recently. In this thesis, we design new switching control law which connect approximate linearization control law and exact linearization control law by fuzzy rules for irregular nonlinear system, ball and beam system. Fuzzy switching controller designed by fuzzy concept is proved that designed scheme overcomes singularities of irregular system, improves unstability problem of switching procedure, and has more efficient control value through simulation. Stability of fuzzy control system proved by Lyapunov's stability theorems.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2763-2765
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• 2003

Generally, we made use of PID control for torque control, speed control and stability, Hence, dynamic characteristic of DC motor has been studied for stable drive and accurate speed control by many engineers. But, in this paper, we applied genetic algorithm to current control for robust control and stability In conclusion, we prove that current control of genetic algorithm can be high efficiency.