• PNF and Movement
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• v.15 no.1
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• pp.51-56
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• 2017

Purpose: The purpose of this study was to examine the effects of the PNF stabilization technique for the hip joint and the bridging exercise on the trunk stabilizer muscles in healthy adults. Methods: Twenty-eight healthy adults were randomly allocated to either a PNF stabilization exercise group (n = 12) or a bridging exercise group (n = 16). The outcome measures included the contraction thickness ratio in the transversus abdominis (TrA), internal oblique (IO), and external oblique (EO), and the TrA lateral slide was assessed during the abdominal drawing-in maneuver using b-mode ultrasound. The researcher measured the abdominal muscle thickness of each participant before the therapist began the intervention and at the moment that the intervention was applied. Between-group comparisons were performed using the Mann-Whitney U test. The level of statistical significance was set at 0.05. Results: The PNF intervention program showed a significant increase in the trunk stabilizer muscle. The percentage of change in the TrA thickness showed a significant interaction between intervention. However, there were no significant differences in the IO and EO between the two groups. Conclusion: The PNF stabilization technique for the hip joint can be used effectively to improve the IO and TrA muscles in healthy adults.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.2
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• pp.129-136
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• 2014

The "WuQinXi" exercise, one of the medical Qi-gongs, is an exercise maximizing human's self healing power and has been confirmed to be effective significantly at several modern researches. There are many exercise therapies in western medcine, such as Willams's flexion exercise, Mckenzie's extension exercise, vertebral stabilization exercise and so on. However, there isn't a special exercise therapy which can be applied for medical practice in oriental medicine. So we selected 24 motions which are related with lumbar movements from 3 type "WuQinXi" exercises ; 20 mode, 30 mode, and 40 mode. And then, we classified them according to lumbar movements as flexion, extention, lateral bending and rotation, and also functions as stabilization and rubbing. Next, with these classifications, we assorted them by kinds of lumbar spinal disease as HIVD(herniation of intervertebral disc), spinal stenosis, spondylolysis and spondylolisthesis, facet joint syndrome, compression fracture and spondylosis. We expect that "WuQinXi" exercise be a exercise therapy for lumbar spinal disease at an oriental medical clinic in this way. Oriental medical doctors will be able to teach easily patients "WuQinXi" exercise's motions at clinic, depending on kinds of lumbar spinal disease each patient suffers from. We plan to study the effect of "WuQinXi" exercise by comparing patients who do the "WuQinXi" exercise with the patients who do the western medical exercise therapy.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.10-18
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• 2010

This paper proposes an image stabilization algorithm for close watching UAV(Unmanned Aerial Vehicle) using motion separation and stabilization mode. The motion of UAV is composed of its actual navigating motion and unwanted vibrating motion so that image sequences obtained from UAV are shaken randomly. In order to stabilize these images we separate the vibrating motion component from UAV motion and remove the effect caused by it from image sequences. In the proposed algorithm the motion and global intensity change of two consecutive images are modeled with 6 motion parameters and 2 intensity change parameters respectively. These modeled parameters are estimated by non-linear least square method based on Gauss-Newton algorithm. The vibrating motion component is separated from the estimated motion using IIR filtering and the geometric deformation caused by it is removed from image sequences. In order to apply the proposed method to real aerial image sequences with many abrupt changes of camera view, we proposed a stabilizing method using two different modes named as stabilizing and non-stabilizing mode. Experimental results show that the accuracy of motion estimation is 99% and the efficiency of removing the vibrating motion component is 90%. We apply the proposed method to real aerial image sequences and verified its stabilizing performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.7
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• pp.587-595
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• 2006

A system operating algorithm was developed for the effective operation of a multi-type air-conditioning system. The system operating algorithm includes control algorithms for a safety mode, an initial operating mode, a stabilization mode, a fault diagnosis mode, an efficiency mode, and a tracking mode. Various tests were performed to show the effectiveness of these algorithms. Tests showed good results for the operation of a multi-type air-conditioning system. Therefore, these algorithms developed for this study may be used for the effective control of a multi-type air-conditioning system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1708-1712
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• 2008

This paper describes a linear matrix inequality (LMI) approach to the design of robust low-order power system stabilizers (PSSs), which are used to damp out local-mode oscillations of synchronous generators. The performance of a PSS is expressed as the location of the closed-loop poles, and a single fixed-gain pole-placement controller is synthesized for a wide range of operating conditions. The synthesis results in simultaneous regional pole-placement stabilization. and is formulated as an LMI feasibility problem with a rank condition. A penalty method is applied to solve the rank-constrained LMI problem. Numerical experiments with a single-machine connected to an infinite bus system were performed to demonstrate the proposed method.

• Journal of KSNVE
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• v.9 no.4
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• pp.714-719
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• 1999

Because the residual vibration of a gun barrel acts negatively on the firing of a large calibers gun, the fast stabilization of theresidual vibration is indispensible to the precise and successive firing. In this study, the residual vibrations of a gun barrel carrying a bore evacuator and a muzzle brake are investigated by the experimental method. The influence of the eigenfrequencies and the mode shapes of gun barrel on the fast stabilization of the residual vibration is studied for the various masses of bore evacuator and muzzle brake, the possition of bore evacutor. Also the relationships between the funcamental frequencies and the settling times of the gun barrel are investigated for the various parameters. The experiments to reduce the residual vibration using the viscoelastic damping treatment gives the best result among the various treatments for the reduction of residual vibration of the system.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.540-549
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• 1999

In this paper, the vibration suppression scheme based on a model referece approach is proposed. The vibration results from the coupling of the system and its frequency are given by the mechanical factors. In the proposed scheme, a low frequency vibration mode is transferred to high one. And also its damping ratio can be increased without any mechanical redesign. Therefore, bandwidth and open loop gain of the plant are increased and the performance of the system can be improved. This paper analyzes the proposed vibration suppression scheme, which is compared with the conventional control scheme for mechanical resonance suppression. For proving the realistic validity, we apply the proposed scheme to a LOS(Line Of Sight) stabilization system which has vibration effect. Finally, the proposed scheme is verified through simulations and experiments.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.330-339
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• 1996

The primary objective of this paper is to grasp characteristics of unit system, for the stabilization of stablized truss structure that is an assemblage of unit system by prestress. This unit system is composed of a central post and eight cables, and is connected by hinge joints, and stabilized by the self-equilibrated stress system. As this unit structures itself is a statically closed and stabilized system individually, it can be employed to assemble a structure with a variety of configuration. In this paper, for the stabilization of truss structure stabilized by cable tension, it is proposed the self-equilibrated axial mode equation and the range of the various geometrical parameter about unit system.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.83-85
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• 1997

In this paper, a self-tunning fuzzy inference technique for stabilization of the inverted pendulum system is proposed. The facility of this self-tunning fuzzy controller which has swing-up control mode and a stabilization one, moves a pendulum in an initial natural stable equilibrium point and a cart in arbitrary position, to an unstable equilibrium point and a center of rail. Specially, the virtual equilibrium point(${\phi}_{VEq}$) which describes functionally considers the interactive dynamics between a position of cart and a angle of inverted pendulum is introduced. And comparing with the convention optimal controller, the proposed self-tunning fuzzy inference structure made substantially the inverted pendulum system robust and stable.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.875-879
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• 1998

A fault on the transmission line results in the variation of reactance and parametric uncertainties in the power system dynamics. In this case, we need a robust control to cope with these uncertainties. A sliding mode control, a sort of robust control, is known to be robust to parametric or state-dependent uncertainties if the bounding function of uncertain terms is determined a priori. However, in general, we can not readily determine the bounding function for the complex systems. Hence, in this paper we introduce a fuzzy system which can estimate the bounding function in relatively simple way. By the use of the proposed fuzzy system, determination of bounding function is made easier. We applied the proposed scheme to the stabilization of power system under the sudden fault on the transmission lines. The simulation result verifies the effectiveness of the scheme.