• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.223-226
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• 2008

This paper presents an effectiveness of a four-link mechanism with a tip which has four joints, but only one is an active joint. Even though the degree-of-freedom of the mechanism is one, it can be applied to implement a combined joint motion adequately. So, this paper analyzes its motion for effective robotic applications.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.10
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• pp.25-31
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• 1995

In this paper, a direct drive scalar robot manipulator is constructed and its mechanical machanism for operation is explained. Also, a motion controller board for the direct drive robot manipulator was developed where the IBM 486 computer is the main controller. For the developed direct drive robot, a force/motion control algorithm based on an active compliance scheme is developed. A preliminary experiment using the developed direct drive for a peg-in-hole job was done by implementing the control algorithm.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.3
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• pp.253-263
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• 2004

The problem considered in this paper is about the collocation of sensor and actuator for the active control of sound and vibration. It is well-known that a point collocated sensor-actuator pair offers an unconditional stability with very high performance when it is used with a direct velocity feedback (DVFB) control, because the pair has strictly positive real (SPR) property. In order to utilize this SPR characteristics, a matched piezoelectric sensor and actuator pair is considered. but this pair suffers from the in-plane motion coupling problem with the out-of-plane motion due to the piezo sensor and actuator interaction. This coupling phnomenon limits the stability and performance of the matched pair with DVFBcontrol. As a new alternative, a point sensor and distributed piezoelectric actuator pair is also considered, which provides SPR property in all frequency range when the pair is implemented on a clamped-clapmed beam. The use of this sensor-actuator pair is highly expected for the applications to more practical active control of sound and vibration systems with the DVFB control strategy.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2809-2811
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• 2005

In this paper, we address an active vibration control system, which suppresses the vibration engaged by magnetically levitated stage. The stage system consists of a levitating platen with four permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion via the vertical and horizontal forces. In the stage system, which represents the settling-time critical system, the motion of the platen vibrates mechanically. We designed an active vibration control system for suppressing vibration due to the stage moving. The command feedforward with inertial feedback algorithm is used for solving stage system's critical problems. The components of the active vibration control system are accelerometers for detecting stage tables's vibrations, a digital controller with high precise signal converters, and electromagnetic actuators.

• Structural Engineering and Mechanics
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• v.36 no.3
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• pp.381-399
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• 2010

A fuzzy hybrid control technique using a semi-active tuned mass damper (STMD) has been proposed in this study for mitigation of wind induced motion of a tall building. For numerical simulation, a third generation benchmark is employed for a wind-excited 76-story building. A magnetorheological (MR) damper is used to compose an STMD. The proposed control technique employs a hierarchical structure consisting of two lower-level semi-active controllers (sub-controllers) and a higher-level fuzzy hybrid controller. Skyhook and groundhook control algorithms are used as sub-controllers. When a wind load is applied to the benchmark building, each sub-controller provides different control commands for the STMD. These control commands are appropriately combined by the fuzzy hybrid controller during realtime control. Results from numerical simulations demonstrate that the proposed fuzzy hybrid control technique can effectively reduce the STMD motion as well as building responses compared to the conventional hybrid controller. In addition, it is shown that the control performance of the STMD is superior to that of the sample TMD and comparable to an active TMD, but with a significant reduction in power consumption.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.12
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• pp.1321-1325
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• 2013

In this paper, we proposed an air bearing stage with active magnetic preloads in vertical directions compensating motion errors and attenuating vibrations to improve dynamic characteristics. This preloaded design gives simpler configuration of the stage, and active control of preload can be used for compensating motion errors by feedforward method. To improve dynamic characteristics, vibration of the table is monitored by an accelerometer, and controlled by a DSP based digital controller with integrator and band pass filters for suppressing roll and pitch vibration modes. The modes were evaluated by measuring frequency response functions, and compared with compensated responses. This showed effective results for suppressing poorly damped regenerative vibration of air bearings.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.15 no.1
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• pp.64-71
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• 2009

Purpose: to purpose prevent to dysfunction and decrease to pain level use to active therapeutic movement and sling manual, stability exercise in shortening hamstring chronic back patient. Methods: The patient's complain was Buttock and Lower Back Pain due to dysfunction posture work. The subject's initial Pain Scale was 60 of 100(VAS). The Subject Treatment to Sling Mobility exercise, Home exercise, ATM, Sling Stability exercise, sensory motor training During 8weeks for 18 times. Results: The result was Visual Analog Scale(VAS)was decreased 10 of 100 after treatment. Conclusion: Visual Analog Scale(VAS)was decreased 10 of 100 after treatment. Functional Leg Length Was recover to same level. Trunk Flexibility was increase to 18cm. Active Knee Extension ankle was decrease to $15^{\circ}$ limit range of motion due to Lt. Hamstring Shortening limit range of motion $30^{\circ}$. GPS(Gobal Postural System)test was recover to same level. This case study need to sufficient data and times.

• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.286-291
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• 2019

Purpose: This study examined the effects of self-volar gliding combined with a strap and wrist distraction on pain and the active and passive wrist extension range of motion (ROM) in subjects with dorsal wrist pain during partial weight bearing of the hand. Methods: Thirty subjects (14 males and 16 females) with dorsal wrist pain during partial weight bearing through the hand participated in this study. The two different self-volar gliding techniques were performed for each group. Self-volar gliding using a strap (SVGS) and SVGS and wrist distraction (SVGSD) were performed five times for one week for each group. The active and passive ROM of wrist extension and the peak pressure pushed by the hand at pain (PPHP) were measured. An independent t-test was used to compare the improvements of these elements between the two different self-volar gliding techniques. The level of statistical significance was at ${\alpha}=0.05$. Results: The active and passive ROM of wrist extension and PPHP were greater in both self-volar gliding groups after the one week intervention. On the other hand, these parameters were greater in the SVGSD group than in the SVGS group (p<0.05) Conclusion: SVGSD is recommended to improve the active and passive ROM of wrist extension and PPHP in subjects with dorsal wrist pain during partial weight bearing of the hand.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.17-25
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• 2016

Purpose: This study was aimed to determine the effects of thoracic spine thrust manipulation on muscle activities of the scapular upward rotators and middle deltoid, active range of motion (AROM), shoulder pain, and rounded shoulder posture in young adults with rounded shoulder. Methods: The subjects were 30 young adults (14 males, 16 females) with rounded shoulder. Thirty subjects were randomly assigned to an experimental (manipulation) and control (placebo) groups of fifteen subjects respectively. The manipulation group received the manipulation (high velocity, low amplitude), which was performed by a physical therapist with the subject in the supine position and with the arms crossed over the chest and hands passed over the shoulders. For the sham group, the same procedure was performed, with the exception that the high-velocity thrust was not applied. Measurements were taken before and after the intervention. Muscle activity of upper and lower trapezius, serratus anterior, middle deltoid was measured using surface electromyography. Visual analog scale (VAS) was used for shoulder pain. Goniometry was used for shoulder abduction active range of motion (AROM). Straight edge was used for supine rounded shoulder posture (RSP) distance. Results: The muscle activity of the upper trapezius, lower trapezius and middle deltoid muscle increased significantly after the intervention (p<.05). However, no significant difference was observed in serratus anterior muscle (p>.05). The VAS was significantly decreased and AROM significantly increased after the intervention (p<.05). The distance of RSP were not significant (p>.05). The control group showed no differences before and after the intervention (p>.05). Conclusion: The results of this study suggest that thoracic spine thrust manipulation can be an effective component of treatment plan to improve pain and function.

• PNF and Movement
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• v.17 no.2
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• pp.167-175
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• 2019

Purpose: This study aims to determine the effect of Jeonbuk tri-pull taping and proprioceptive neuromuscular facilitation (PNF) exercise on the shoulder's active range of motion, pain, subluxation, upper extremity function, and activities of daily living in patients with stroke. Methods: In this study, Jeonbuk tri-pull taping and PNF exercise were applied to three patients with stroke and subluxation. The tape was removed and new tape applied for two days every Monday, Wednesday, and Friday over six consecutive weeks. PNF exercise was applied five times a week for six weeks. To measure the range of motion, a smart phone clinometer application was used, and the degree of pain was measured using a visual analogue scale (VAS). A jig measuring method was employed to measure the distance of subluxation. The Fugl-Meyer Assessment (FMA) was used to evaluate arm function, and the modified Barthel Index (MBI) was employed to evaluate the activities of daily living. Results: The shoulder's active range of motion was improved in the patients compared to the range of pre-tests, and the pain and subluxation distance were reduced compared to those of pre-tests. Arm function and activities of daily living were increased compared to those of pre-tests. Conclusion: The study results verified that Jeonbuk tri-pull taping and PNF exercise are useful when applied to patients with subluxation and stroke.