• The Journal of Korean Physical Therapy
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• v.17 no.4
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• pp.537-557
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• 2005

The purpose of this study was to investigate the effect of pelvic traction and muscle energy technique(MET) for hemiplegic patients on static standing balance. The scale for static standing balance is measured by using mean balance(%), frequence(Hz), sway area($mm^2$), sway path(mm), max sway velocity(mm/s), ant/post sway angle($^{\circ}$), lateral sway angle($^{\circ}$), sway number, change of pelvic height is measured in relation to the height of ASIS and PSIS. The subjects of this study were thirty hemiplegic patients: 15men and 15 women, with an average ages of 50.80 years. The thirty subjects were divided into 3 group of 10 at random ; ten subjects had pelvic traction after bobath therapy (the pelvic traction group), ten subjects had muscle energy technique after bobath therapy (the MET group), and ten subjects had only bobath therapy (the control group). Static standing balance was measured using BPM (balance performance monitor; data print software version 5.3), pelvic height was measured using height measuring with an adjustable horizontal arm. In order to assure the statistical significant of the result, an one-way ANOVA, the paired t-test, and a person's correlation were applied at the.05 level of significance. The results of this study were as follows: 1) The change in pelvic height were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 2) The change in affected and non-affected on weight bearing were not statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p>.05). 3) The change in frequency were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 4) The change in sway area were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 5) The change in sway pa1h were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 6) The change in max sway velocity were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 7) The change in ant/post sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 8) The change in lateral sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 9) The change in sway number were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). In conclusion, there was a difference between the experimental group and the control group. In the future, we have to study continuously about pelvic traction and muscle energy technique in hemiplegic patients.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.219-227
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• 2002

In this paper, we designed neural network predictive PID controller to control sway happened in transfer of trolley for automatic travel control system. We include dynamic character of nonlinear system, and mathematical expression veny simple used neural network. When various establishment location and surrounding disturbance were approved based on mathematical modelling of crane, controller designed to become effective control location error and vibration angle of two control variables that simultaneously can predictive control. Neural network predictive PID controller produced parameter of PID controller using neural network self-tuner. Neural network self-tuner's input used crane's output and neural network predictive output. Neural network self-tuner using error back propagation algorithm. We analyzed control performance comparison through computer simulation when applied disturbance about sway of location and angle in transfer of crane. The results show that the proposed neural network predictive PID controller has better performances than general PID controller, neural network PID controller.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.73-81
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• 2012

Purpose: The aim of the present study was to measure the standing balance symmetry of stroke patients using a force-plate with computer system, and to investigate the correlation between the standing balance symmetry and that of the walking function in stroke patients. Methods: 48 patients with stroke (34 men, 14 women, $56.8{\pm}11.72$ years old) participated in this study. Static standing balance was evaluated by the weight distribution on the affected and the nonaffected lower limbs, sway path, sway velocity, and sway frequency, which reflected the characteristic of body sway in quiet standing. Dynamic standing balance was evaluated by anteroposterior and mediolateral sway angle, which revealed the limit of stability during voluntary weight displacement. Symmetry index of static standing balance, (SI-SSB) calculated by the ratio of the affected weight distribution for the nonaffected weight distribution, and symmetric index of dynamic standing balance (SI-SDB) by the ratio of the affected sway angle for the nonaffected sway angle. Functional balance assessed by a Berg balance scale (BBS), and the functional walking by 10m walking velocity, as well as the modified motor assessment scale (mMAS). Results: Static balance scales and SI-SSB was the only correlation with BBS (p<0.05). Dynamic balance scales and SI-DSB, not only was correlated with BBS, but also with 10m walking velocity and mMAS (p<0.01). Additionally, there was a significant difference between SI-SSB and that of SI-DSB (p<0.01). Conclusion: The balance and the walking function relate to real life in the stroke showed strong relationships with the dynamic standing balance symmetry in the frontal plane and the ability of anterior voluntary weight displacement in sagittal plane.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.4
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• pp.211-216
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• 2014

In general, gantry robot is very useful handling of heavy objects. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. These approaches require sway angle. But it is very difficult to know sway angle and its derivative. Therefore control algorithm of trolley speed is not practical in general. On the contrary, control strategy using auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And we propose the control strategy and analyse the behavior of the proposed system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.109-115
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• 2012

In this paper, we consider the sway suppression control problem for container cranes with load hoisting. The proposed control law improves the positioning accuracy but also the sway suppression through fast stabilization of the under-actuated sway dynamics, which is based on a class of feedback linearizing control incorporated with an additional control including the sway angle and its rate as well as positioning errors and their rates. For the design of the additional control, a variable structure control with the proper sway damping and simple switching action is employed, thus preventing excessive overshoots of the trolley travelljng and effectively suppressing the residual sway of container arrived at the target position. Simulation results are provided to show effectiveness of the proposed controller in the presence of such uncertainties as winds and the variation of payload weights.

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.77-86
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• 2005

Over the last 10 years, significant changes have taken place in the world of container shipping. The size and the speed of the quay-side crane have been increased considerably. As a result, the stiffness of a crane is decreased and the sway oscillation of cargo may become violent. The purpose of this paper is to determine the design force caused by the sway oscillation of the cargo, lifted by four ropes, with an initial fleet angle, and the governing equations of the lifting system for an anti-sway control system design.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.334-339
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• 2012

Purpose: This study was conducted in order to compare the ability to control postural sway during perturbation when stroke patients received postural sway induced by head rotation. Methods: This study included 15 stroke patients and 15 healthy adults. Each group was measured by 3D motion analysis for determination of the angle of the neck in static position and by balance performance monitor for estimation of swaying angle in both neutral posture and head rotation position. These results were then analyzed in order to compare the healthy control group and the stroke patients group. Results: In both static posture ($60.7{\pm}4.81$) and dynamic posture ($51.46{\pm}6.87$, $70.8{\pm}6.55$), significant decreases were observed in the angle of head rotation of the patient group, compared to the healthy group (p<0.05), and significant decreases were observed in the sway angle of the patient group when in the neutral position ($3.62{\pm}7$, $24{\pm}0.60$) and head rotation ($3.04{\pm}0.80$, $51.46{\pm}6.87$), compared to the healthy group (p<0.05). Conclusion: According to these findings, patients with stroke tend to restrict the ROM of head rotation and swaying angle in dynamic posture and maintain their posture instability using limitation of head movement relative to the trunk and sway angle of area which is larger than that of affected side in unaffected side.

• The Journal of Korean Physical Therapy
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• v.16 no.2
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• pp.99-107
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• 2004

The purpose of this study was to investigate the effect of foot orthotic on postural sway. Subjects were 15 patients(7 men and 8 women) who prescribed foot orthotic at B hospital and L rehabilitation medicine clinic in Seoul. Postural sway during a single limb stance was measured using the CMS 10 Measuring System when subjects positioned on the balance trainer under two treatment conditions(orthotic and nonorthotic). RCSP(resting calcaneal stance position) while subjects were standing on the glass plate was measured using the angle finder after subjects were positioned in prone to divide equally lower leg and calcaneus using the goniometer. The result was as follows. There were significant difference between postural sway of orthotic and nonorthotic conditions(t=4.888, 4.589, p<0.001), and the leg of the small RCSP within a subject has the small postural sway index($x^2=26.000$, p<0.001). In conclusion, foot orthotics provide structural support for detecting and controlling postural sway in patients prescribed foot orthotics.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.1
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• pp.23-31
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• 1997

The sway control problem of pendulum motion of a container hanging on a Portainer Crane, which transports containers from a container ship to trucks, is considered in the paper. The equations of motion are obtained through the Lagrange mechanics and simplified for control purposes. Considering that the fast traveling of trolley and no residual swing motion of the container at the end of acceleration and deceleration are crucial for quick transportation, several velocity patterns of trolley movement including the time-optimal control are investigated. Incorporating the change of rope length, a reference swing trajectory is introduced in the control loop and the error signal between the reference sway angle and the measured sway angle is feedbacked. Proposed control strategy is shown to be robust to disturbances like winds and initial sway motion.

• Korean Journal of Applied Biomechanics
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• v.30 no.3
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• pp.217-223
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• 2020

Objective: The purpose of this study was to analyze the effect of postural sway on the kinematic variables of the putter head during golf putting and to provide information to the importance of postural sway control in the putting stroke for novice golfers. Method: The center of pressure (CoP) and Kinematics variables of the putter head were calculated during 2 m flat golf putting using 8 motion capture cameras (250 Hz) and 2 force plate (1,000 Hz). SPSS 24.0 was used to perform Pearson's correlation coefficient and simple regression analysis, and the statistically significance level was set to .05. Results: As a result of analyzing the correlation between CoP variables and the putter head rotation angle, the CoP moving length, CoP moving range (ML direction), and CoP moving velocity (ML direction) showed a positive correlation with the putter head rotation angle (yaw axis) and were statistically significant. Conclusion: Therefore, In order to perform the accurate putting stroke maintaining the ball's directionality, it is determined that it is important to control posture sway in the ML directions by minimizing the movement and velocity of the CoP.