• Proceedings of the IEEK Conference
• /
• 2001.06d
• /
• pp.89-92
• /
• 2001

In this paper, we propose a new approach for tracking a moving object in moving image sequences using active contour models and optical flow. In our approach object segmentation is achieved by active contours, and object tracking is done by motion estimation based on optical flow. To get more dynamic characteristics, Lagrangian dynamics combined to the active contour models. For the optical flow computation, a method, which is based on Spatiotempo-ral Energy Models, is employed to perform robust tracking under poor environments. A prototype real tracking system has been developed and applied to a contents-based video retrieval systems.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.2 s.95
• /
• pp.15-22
• /
• 1999

This paper demonstrates the feasibility of Shape Memory Alloy (SMA) actuators in controlling the motion of micro active catheter. The dynamic behavior of SMA is obtained by several experiments for the design of the controller. With the control parameters obtained in experiments, temperature feedback control algorithm is proposed and realized. The prototype of micro active catheter is fabricated, and its control performance which uses the designed controller is investigated. The results obtained show the potential of the SMA as viable means for actuating the micro active catheter.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.11 no.7
• /
• pp.261-266
• /
• 2001

The flexural vibration of laminated composite beams with active and passive constrained layer damping has been investigated to design a structure with maximum possible damping capacity. The equations of motion are derived fro flexural vibrations of symmetrical,. multi-layer laminated beams. The damping ratio and model damping of the first bending mode are calculated by means of iterative complex eigensolution method. The direct negative velocity feedback control is used for the active constrained layer damping. It is shown that the flexible laminated beam is more effective in the vibration control for both active and passive constrained layer damping. and this paper addresses a design strategy of laminated composite under flexural vibrations with constrained layer damping.

• The Journal of Korean Physical Therapy
• /
• v.29 no.4
• /
• pp.187-193
• /
• 2017

Purpose: The purpose of this study was to confirm the immediate effect of wrist joint mobilization with taping on the range of motion, grip strength, and spasticity. Methods: Thirty stroke patients were randomly divided into two groups: the joint mobilization with taping group (n=15) and a taping group (n=15). For measurement of spasticity and joint range of motion, the modified Tardieu scale, active and passive range of motion of wrist flexion, as well as extension were measured by the Rapael smart glove, and for grip strength measurement, grip dynamometer was performed. Results: The experimental group showed a significant improvement in the range of motion, grip strength, and spasticity after 10 minutes of taping (p<0.05), no significant difference was found in the control group (p>0.05). However, there was no significant difference between the two groups (p>0.05). Conclusion: The study found that wrist joint mobilization with taping has an immediate effect on wrist range of motion, grip strength, and spasticity in stroke patients, whereas it was not effective in the control group with just taping. The long-term change still needs to be evaluated, when taking into consideration of the carryover effect.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.1
• /
• pp.446-467
• /
• 2012

In this paper, the analysis and design of a motion simulator (based on the approach taken by interactive virtual reality (VR) entertainment systems) is conducted. The main components of the system include a bilateral control interface, simulation and a motion simulator control scheme. The space entertainment system uses a virtual environment that enables operators to feel the actual feedback sensing and distorted motion from the virtual environment, just as they would in the real environment. The space entertainment system integrates the dynamics of the motion simulator and the virtual environment and the operator maneuvers a steering wheel to interact with the system. The multiple bilateral control schemes employ a dynamical controller, which is designed by considering the velocity and acceleration that the operator imposes on the joystick, the environmental changes imposed on the motion simulator. In addition, we develop a calculated method to evaluate the Ratio of the simulation results. It is shown that the proposed control scheme can improve the performance of the visual entertainment system. Experiments are conducted on the virtual reality entertainment system to validate the theoretical developments.

• Journal of KSNVE
• /
• v.7 no.3
• /
• pp.387-392
• /
• 1997

This paper concerns a SCARA robot with the flexible forearm linked to the rigid upper arm. The equations of motion are derived by the Lagrangian mechanics. For controller design, the perturbation approach is taken to separate the original equations of motion into linear equations describing small perturbed motions and nonlinear equations describing purely rigid motion of the robot. To effect the desired payload motion, open loop control inputs are determined based on the inverse dynamics of the latter. In order to reduce the positional error during maneuver, an active vibration suppression is done. To this end, a feedback control is designed for robustness against disturbance on the basis of the linear equations and the LQR theory modified to have a prescribed degree of stability. The proposed control scheme shows satisfactory performances in experiments as well as in numerical simulations.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.582-584
• /
• 2006

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system's compact size, low-cost, ease of installation, and high frame rates are suitable for high speed motion tracking in games.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.225-228
• /
• 1996

This paper concerns a SCARA type robot with the second arm flexible. Its equations of motion are derived by the Lagrangian mechanics. For controller design, the perturbation approach is taken to separate the original equations of motion into linear equations describing small perturbed motions and nonlinear equations describing purely rigid motion of the robot. To effect the desired payload motion, open loop control inputs are first determined based on the inverse dynamics of the latter. Next, in order to reduce the positional error during maneuver, an active vibration suppression is done. To this end, a feedback control is designed for robustness against disturbance on the basis of the linear equations and the LQR theory modified with a prescribed degree of stability. The numerical simulations results show the satisfactory control performance.

• Earthquakes and Structures
• /
• v.3 no.6
• /
• pp.869-887
• /
• 2012

Ground motion scaling techniques are actively debated in the earthquake engineering community. Considerations such as what amplitude, over what period range and to what target spectrum are amongst the questions of practical importance. In this paper, the effect of various ground motion scaling approaches are explored using three reinforced concrete prototypical building models of 8, 12 and 20 stories designed to respond nonlinearly under a design level earthquake event in the seismically active Southern California region. Twenty-one recorded earthquake motions are selected using a probabilistic seismic hazard analysis and subsequently scaled using four different strategies. These motions are subsequently compared to spectrally compatible motions. The nonlinear response of a planar frameidealized building is evaluated in terms of plasticity distribution, floor level acceleration and uncorrelated acceleration amplification ratio distributions; and interstory drift distributions. The most pronounced response variability observed in association with the scaling method is the extent of higher mode participation in the nonlinear demands.

• Journal of the Korean Society of Physical Medicine
• /
• v.6 no.1
• /
• pp.81-92
• /
• 2011

Purpose : The purpose of this study was to compare combined exercise program group to conventional physiotherapy for patients with chronic neck pain. Methods : Participants were randomly allocated to two groups by experimental(n=17) and control(n=17). Combined exercise program group involved stretching, stability, strengthening and endurance, proprioceptive exercises along with an educational programme. Patient attended for 60min, three times a weeks. Control group was treated as conventional physiotherapy on 40 min, three times a weeks. Outcome variables included pain, disability, range of motion, fatigability at 0 and 6 weeks. Results : Pain, Disability Index, Fatigability significantly decreased(p<.05) and Range of motion improved significantly after active exercise program(p<.05). In conclusion. Combined exercise program improves pain and disability, range of motion, fatigability. Conclusion : These results suggest that combined exercise program is suitable for chronic neck pain.