• Journal of Magnetics
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• v.22 no.1
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• pp.155-161
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• 2017

This paper presents a new nonmechanical rehabilitation system driven by magnetic force. Typically, finger rehabilitation mechanisms are complex mechanical systems. The proposed method allows wireless operation, a simple configuration, and easy installation on the hand for active actuation by magnetic force. The system consists of a driving coil, driving magnets (M1), and auxiliary magnets (M2 and M3), respectively, at the finger, palm, and the center of coil. The magnets and the driving coil produce three magnetic forces for an active motions of the finger. During active actuations, magnetic attractive forces between M1 and M2 or between M1 and M3 enhance the flexion/extension motions. The proposed system simply improves the extension motion of the finger using a magnetic system. In this system, the maximum force and angular variation of the extension motion were 0.438 N and $49^{\circ}$, respectively. We analyzed the magnetic interaction in the system and verified finger's active actuation.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.34-44
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• 2000

In this paper, a modified skyhook control for the semi-active Macpherson suspension system is investigated. A new model for the semi-active type suspension, which incorporates the rotational motion of the unsprung mass, is introduced and an output feedback control law using the skyhook control method is derived. The gains in the skyhook controller are adaptively adjusted by estimating the road conditions. Because two vertical acceleration sensors, one for the sprung mass and another for the unsprung mass, are used rather than using the angle sensor for the rotational motion of the control arm, the relative velocity of the rattle space is filtered using the acceleration signals. For testing the control performance, the actual damping force has been incorporated via the hardware-in-the-loop simulations. The performances of a passive damper and a semi-active damper are compared. Simulation results are provided.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.3
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• pp.603-610
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• 1998

This paper develops a 7 DOF vehicle model to study the effects of the active suspension on ride. The model is used to derive a control law for the active suspension using a full state linear optimal control technique. A wheelbase preview type active suspension is also considered in the control law derivation. The time delay between wheelbases is approximated using Pade approximation technique. The ride model is extended to a 14 DOF handling model. The 14 DOF handling model includes lateral, longitudinal, yaw and four wheel spin motions in addition to the 7 DOF ride model. A control law which is derived considering only ride related parameters is used to study the effects of the active suspension on a vehicle handling. J-turn maneuver simulation results show that the active suspension has a slower response in lateral acceleration and yaw rate, a bigger steady state lateral acceleration and an oversteer tendency. Lane changing maneuver simulation results show that the active suspension has a little bigger lateral acceleration but a much smaller roll angle and roll motion. Braking maneuver simulation results show that the active suspension has a much smaller pitch angle and pitch motion.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1074-1080
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• 2006

Motion capture systems are gaining popularity in entertainment, medicine, sports, education, and industry, with animation and gaming applications for entertainment taking the lead. A wide variety of systems are available for motion capture, but most of them are complicated and expensive. In the general class of optical motion capture, two or more optical sensors are needed to measure the 3D positions of the markers attached to the body. Recently, a 3D motion capture system using two Position Sensitive Detector (PSD) optical sensors was introduced to capture high-speed motion of an active infrared LED marker. The PSD-based system, however, is limited by a geometric calibration procedure for two PSD sensor modules that is too difficult for common customers. In this research, we have introduced a new system that used a single PSD sensor unit to obtain 3D positions of active IR LED-based markers. This new system is easy to calibrate and inexpensive.

• Journal of Korean Physical Therapy Science
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• v.16 no.4
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• pp.11-17
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• 2009

Background: The purpose of this study was to find out the real truth of the effect of PROM (Passive range of motion) and AAROM (Active assistive range of motion) exercise on increasing the knee flexion. This randomized, controlled trial examined whether or not the incorporation of PROME(passive range of motion exercise) to a postoperative rehabilitation protocol would offer a better clinical outcome after TKA (Total knee arthroplasty) Method: The subject (n=36) measured range of motion (ROM).18 consecutive patients who underwent TKAs at SNUH dept. OS received PROME for knee by a physical therapist during the physiotherapy sessions and not for the other 18 patients who underwent TKAs received No-PROME (AAROME) for knee by herself. Result: There were significant differences in the PROME group, No-PROME group ROM progress width And there were significant differences in the PROME group between No-PROME group ROM improvement width. Conclusion: This study demonstrates that the incorporation of PROME does offer additional clinical benefits to the patients after TKA. Our findings may suggest that encouraging patients to perform PROM exercises would be a better option and that physiotherapy session by a physical therapist holds good even now.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.409-413
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• 2022

Objective: This study aims to compare the range of motion of the joints by applying the contraction and relaxation techniques used in manual therapy as electrical stimulation treatment. Based on this, we would like to propose the possibility of using motor nerve electrical stimulation therapy for musculoskeletal physical therapy. Design: Single-arm interventional study Methods: Active and passive straight leg raising tests were performed on 20 healthy men and women in their 20s to measure the angle of hip joint flexion. Then, the electrical stimulation time was set to 10 seconds and 5 seconds of rest, and motor nerve electrical stimulation of 1 Hz was applied with the maximum strength that could withstand the hamstring muscles for 10 minutes. After electrical stimulation, straight leg raising tests again to confirm the range of motion of the hip joint flexion. Results: As a result of this study, it was confirmed that the joint range of motion was significantly improved for both active and passive straight leg raising tests after application of motor nerve electrical stimulation(p<.05). Conclusions: With a strong electrical stimulation treatment of 1 Hz, the effect similar to the contraction and relaxation technique used in manual therapy was confirmed through the joint range of motion. In the future, motor nerve electrical stimulation therapy can be used for musculoskeletal physical therapy to provide a new approach for patients with reduced pain and joint range of motion due to muscle tension.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.2
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• pp.1-7
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• 2016

Background: The purpose of this study was to investigate the effects of between modified mulligan technique and modified mulligan technique with taping on the active range of motion & passive range of motion, scapula index into the stroke patients. Methods: The subjects with stroke were randomly divided into two groups. Group 1 (n=9) was conducted modified mulligan technique and Group 2 (n=9) was conducted modified mulligan technique with taping week three times for 4weeks. Active range of motion (AROM), passive range of motion (PROM) and scapula index (SI) were measured by goniometer and tape measure. Wilcoxon signed-rank tests were used to compare differences before and after intervention. Mann-Whitney U-test were conducted to compare before to after intervention in the two groups. Results: AROM was significantly different both groups (p<.05) and between groups were not significantly different into pre and post intervention (p>.05). PROM was significantly different both groups (p<.05) however, between groups were not significantly different into pre and post intervention (p>.05). SI was significantly different only group 2 and between groups were not significantly different (p>.05). Conclusions: This study demonstrated effective bo-th modified mulligan technique and modified mulligan technique with taping on the active range of motion and passive range of motion. Because only modified mulligan technique with taping are effective on the scapula index we recommend modified mulligan technique with taping than modified mulligan technique.

• Smart Media Journal
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• v.6 no.3
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• pp.49-56
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• 2017

Images and Videos that include the human face contain a lot of information. Therefore, accurately extracting human face is a very important issue in the field of computer vision. However, in real life, human faces have various shapes and textures. To adapt to these variations, A model-based approach is one of the best ways in which unknown data can be represented by the model in which it is built. However, the model-based approach has its weaknesses when the motion between two frames is big, it can be either a sudden change of pose or moving with fast speed. In this paper, we propose an enhanced human face-tracking model. This approach included human face detection and motion estimation using Cascaded Convolutional Neural Networks, and continuous human face tracking and modeling correction steps using the Active Appearance Model. A proposed system detects human face in the first input frame and initializes the models. On later frames, Cascaded CNN face detection is used to estimate the target motion such as location or pose before applying the old model and fit new target.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.135-136
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• 2006

A precise linear motion stage supported by magnetically preloaded air bearings is introduced where preloading magnetic actuators are combined with permanent magnets and coils to adjust air bearing clearance by controlling magnetic force actively. Each of the magnetic actuators has a permanent magnet generating nominal magnetic flux for required preload and a coil to perturb the magnetic force resulting adjustment of air-bearing clearance. The characteristics of porous aerostatic bearing are analyzed by numerical analysis, and analytic magnetic circuit model is driven for magnetic actuator to calculate nominal preload and variation of force due to current. A 1-axis linear stage motorized with a coreless linear motor and a linear encoder is built for verifying this design concept. With the active magnetic preloading actuators controlled with DSP board and PWM power amplifiers, the active on-line adjusting tests about the vertical, pitching and rolling motion were performed, and the result shows very good linearity.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.74-82
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• 2004

In this paper, a disturbance feedforward compensator design technique is proposed for an active magnetic bearing system subject to base motion for attenuating disturbance responses. In the consideration of the requirements on the model accuracy in the model based compensator designs, an experimental feedforward compensator design based on adaptive estimation by means of the Multiple Filtered-x least mean square(MFXLMS) algorithm is proposed. The performance and the effectiveness of the proposed technique will be presented in the succeeding paper in which the proposed technique is applied to a 2-DOF active magnetic bearing system subject to base motion.