• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.254-259
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• 1992

In this paper, we propose an optimal method for the tracking a trajectory of the end-effector of flexible robot arms with multiple joints. The proposed method finds joint trajectories and joint torques necessary to produce the desired end-effector motion of flexible manipulator. In inverse kinematics, optimized joint trajectories are computed from elastic equations. In inverse dynamics, joint torques are obtained from the joint equations by using the optimized joint trajectories. The equations of motion using finite element method and virtual work principle are employed. Optimal control is applied to optimize joint trajectories which are computed in inverse kinematics. The simulation of flexible planner manipulator is presented.

• Transactions on Control, Automation and Systems Engineering
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• v.1 no.1
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• pp.32-43
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• 1999

Adaptive robust control scheme is introduced for flexible joint manipulator with nonlinearities and uncertainties. The system does not satisfy the matching condition due to insufficient actuators for each node. The control only relies on the assumption that the bound of uncertainty exists. Thus, the bounded value does not need to be known a prior. The control utilizes the update law by estimating the bound of the uncertainties. The control scheme uses the backstepping method and constructs a state transformation. Also, stability analysis is done for both transformed system and original system.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.1
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• pp.29-36
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• 2005

The purpose of this study was to evaluate change of path length center of body on sacroiliac joint mobilization. The subjects were consisted of sixty healthy adult two decade(28 females. 32 males; mean aged 22.2) from 20 to 29. All subjects randomly assigned to the control group, sacroiliac joint mobilization group. sacroiliac joint mobilization group received sacroiliac joint mobilization for 2-3 minutes per day and three times a week during 3 weeks period. The study carried out to determine the change of path length center of body on sacroiliiac joint mobilization from July 1, 2004 through september 30, 2004. Active balancer(SAKAI EAB-100) was used to measure equilibrium ability. All measurements of each subjects were measured at pre-experiment and post-experiment. The results of this study were summarized as follows: 1. The WPL of control group, sacroiliac joint mobilization group was no significantly differences at pre-experiment but significantly reduced post-experiment(p<.05). The results of analyzed effects of WPL was significantly reduced between experiment type of control group, sacroiliac joint mobilization group according to pre-experiment and post-experiment(p<.05). 2. The UPL of control group, sacroiliac joint mobilization group was no significantly differences at pre-experiment but significantly reduced post-experiment(p<.05). The results of analyzed effects of UPL was significantly reduced between experiment type of control group, sacroiliac joint mobilization group according to pre-experiment and post-experiment(p<.05). Conclusionally these data suggest that a 3-week S-I joint mobilization improved equilibrium. Additional randomized controlled trials to more fully investigate treatment effects and factors that may mediate these effects are needed.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.2
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• pp.121-125
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• 2008

Purpose : The objective of this study was conducted to find out the treatment of joint problems. Methods : This is a literature study with books, seminar note and international course books. Results : Passive oscillation and distraction movement therapy is only joint mobilization and pain control. In the joint therapy need muscle strengthening, training of eccentrical control and neurophysiological therapy for joint mobility, stability, stability of mobility and skill. Conclusion : Joint therapy is not only joint mobility but also strengthening of soft tissue. Need the neurophysiological therapy those are use of ventromedial motor nucleus and dorsolateral motor nucleus, reciprocal inhibition, eccentrical muscle contraction training, proprioceptors and exteroceptor for structures and functional activities. For the pain control, reduce swelling, keeping GAGs and functional activities need direct and indirect therapy.

• Computers and Concrete
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• v.32 no.4
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• pp.411-423
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• 2023

The rapid development of road transport has increased the number of bridges that require widening. A critical issue in the construction of bridge widening is the influence of vibrations of the old bridge on the casting of wet joint concrete between the old and new bridges owing to the running traffic. Typically, the bridge is closed to traffic during the pouring of wet joint concrete, which negatively affects the existing transportation network. In this study, a newly developed microscopic traffic load modeling approach and the vehicle-bridge interaction theory are incorporated to develop a refined numerical framework for the analysis of random traffic-bridge coupled dynamics. This framework was used to investigate traffic-induced vibrations at the wet joint of a widened bridge. Based on an experimental study on the vibration resistance of wet joint concrete, traffic control strategies were proposed to ensure the construction performance of cast-in-site wet joint concrete under random traffic without interruption. The results show that the vibration displacement and frequency of the old bridge, estimated by the proposed framework, were comparable with those obtained from field measurements. Based on the target peak particle velocity and vibration amplitude of the wet joint concrete, it was found that traffic control measures, such as limiting vehicle gross weight and limiting traffic volume by closing an additional traffic lane, could ensure the construction performance of the wet joint concrete.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.922-927
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• 2007

The present urban maglev which has been developed in Korea is controlled by 4-edge control method over each bogie. The control output which is derived from two gap sensors and one vertical acceleration sensor controls magnet to maintain a nominal gap. But, the gap signal acts as a big disturbance in rail joint though two gap sensors are used and finally result in unstable response and poor ride comfort. This paper treats of a method to compensate the gap signal in rail joint for the levitation control of urban maglev. The physically abnormal change of gap is detected when one gap sensor passes a rail joint, the disturbance of gap in rail joint is estimated. Finally the disturbance in gap signal is eliminated by processing the information of vehicle speed and estimated disturbance in when the other gap sensor passes a rail joint.

• Advances in concrete construction
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• v.6 no.5
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• pp.527-543
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• 2018

Crack control of precast members is crucial for durability. However, there is no clear provision to check the crack width of precast joints. This study presents an experimental investigation of loop joint details for use in a precast bridge deck system. High strength concrete of 130 MPa was chosen for durability and closer joint spacing. Static tests were conducted to investigate the cracking and ultimate behavior of test specimens. The experimental results indicate that current design codes provide reasonable estimation of the flexural strength and cracking load of precast elements with loop joint of high strength concrete. However, the crack width control of the loop joints with high strength concrete by the current design practices was not appropriate. Some recommendations to improve crack control of the loop joint were derived.

• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.285-295
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• 2005

The purpose of this study was to evaluate effects of sacroiliac joint mobilization and lumbopelvic stabilizing exercises on the equilibrium ability. The subjects were consisted of ninety healthy adult two decade(43 females. 47 males; mean aged 22.1) from 20 to 29. All subjects randomly assigned to the control group, sacroiliac joint mobilization group, lumbopelvic stabilizing exercises group. Lumbopelvic stabilizing exercises group received lumbopelvic stabilizing exercises for 30 minutes, sacroiliac joint mobilization group received sacroiliac joint mobilization for 2-3 minutes per day and three times a week during 3 weeks period. Active balancer(SAKAI EAB-100) was used to measure equilibrium ability. All measurements of each subjects were measured at pre-experiment, after 10 days, and post-experiment. The results of this study were summarized as follows: 1. The WPL of control group, sacroiliac joint mobilization group, lumbopelvic stabilizing exercises group was no significantly differences at pre-experiment(p>.05), but significantly reduced after 10 days and post-experiment(p<.05). The results of analyzed effects of WPL was significantly reduced between experiment type of control group, sacroiliac joint mobilization group, lumbopelvic stabilizing exercises group according to pre-experiment, after 10 days, and post-experiment(p<.05). 2. The RA of control group, sacroiliac joint mobilization group, lumbopelvic stabilizing exercises group was no significantly differences at pre-experiment(p>.05), but significantly reduced after 10 days, and post-experiment(p<.05). The results of analyzed effects of RA was significantly reduced between experiment type of control group, sacroiliac joint mobilization group, lumbopelvic stabilizing exercises group according to pre-experiment, after 10 days, and post-experiment(p<.05). Conclusionally these data suggest that a 3-week SI joint mobilization and lumbopelvic stabilizing exercises improved equilibrium. Additional randomized controlled trials to more fully investigate treatment effects and factors that may mediate these effects are needed.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.61-70
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• 2019

Objective: This study aimed to investigate the characteristics of the declination of the subtalar joint rotation axis and the structural features of the ankle joint complex such as rear-foot angle alignment and ligament laxity test between chronic ankle instability (CAI) patients and healthy control. Method: A total of 76 subjects and CAI group (N=38, age: $23.11{\pm}7.63yrs$, height: $165.67{\pm}9.54cm$, weight: $60.13{\pm}11.71kg$) and healthy control (N=38, age: $23.55{\pm}7.03yrs$, height: $167.92{\pm}9.22cm$, weight: $64.58{\pm}13.40kg$) participated in this study. Results: The declination of the subtalar joint rotation axis of the CAI group was statistically different from healthy control in both sagittal slope and transverse slope. The rear-foot angle of CAI group was different from a healthy control. Compared to healthy control, they had the structure of rear-foot varus that could have a high occurrence rate of ankle varus sprain. CAI group had loose ATFL and CFL compared to the healthy control. Conclusion: The results of this study showed that the deviation of the subtalar joint rotation axis and the structural features of the ankle joint complex were different between the CAI group and the healthy control and this difference is a meaningful factor in the occurrence of lateral ankle sprains.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.927-932
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• 2007

This paper proposes a robust back-stepping control with polynomial-type PD input for flexible joint robot manipulators to overcome parameter uncertainty. In the first step, a fictitious control is designed with polynomial-type PD input for the rigid link dynamic by the H-infinity control method. In second and third steps, the other fictitious control and real control are designed using saturation control and polynomial-type PD input based on the Lyapunov's second method. In each step, the designed robust inputs satisfy the L2-gain, which is equal to or less than gamma in the closed loop system. In contrast with the previous researches, the proposed method proves performance relations with PD gain from the robust gain. The performance robustness of the proposed control is verified through a 2-DOF robot manipulator with joint flexibility.