• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.5
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• pp.1025-1030
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• 2001

As the pre-stage of making 3D stabilizing systems, at this paper designed 2D stabilizing system. This is composed of two axes stabilizing platform to preserve targeted direction while vehicle is moving. The system maintains stabilization by recovering error using the rate gyro with DSP TMS320F240 as controller, vibratory rate gyro (Tokimec co. TFG -l60D) as gyro scope, SD1015B52-1·SD1004C04-l/DM1015B DM1004C as direct drive driver/motor, PI control as control algorithm. This paper got a comparably good stabilization.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.48.5-48
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• 2001

The resulting stabilizing controller in this paper consists of the disturbance estimator and the gain scheduled controller. The disturbance estimator tracks the unknown external disturbance and its derivative information in the closed-loop control system using fuzzy logic based adaptation law. Moreover, the gains of the stabilizing controller are appropriately scheduled according to the estimated values. Furthermore, since the estimation law is combined with the stabilizing controller in the closed control loop, it asymptotically minimizes the estimation error. In order to conrm the usefulness of the proposed control scheme, it is applied to the magnetic suspension systems.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.429-432
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• 2004

In this paper, we derive the guaranteed bound of the horizon size for the stabilizing receding horizon control(RHC). From the convergence property of the solution to the Riccati equation, it is shown that the lower bound can be represented in terms of the parameters in the given system model, which makes an off-line calculation possible. Additionally, it is shown to be able to obtain the stabilizing RHC without respect to the final weighting matrix. The proposed guaranteed bound is obtained numerically via simulation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.13 no.2
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• pp.21-30
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• 2007

Purpose: The purpose of this study was to evaluate effects of lumbar vertebrae mobilization and lumbar stabilizing exercises on the muscle strength. Methods: The subject were sixty healthy adult(30 females. 30 males) two decade from 21 to 35. All subjects randomly assigned the control group, lumbar vertebrae mobilization group, lumbar stabilizing exercises group. lumbar stabilizing exercises group received lumbar stabilizing exercises for 30 minutes, lumbar vertbrae mobilization group received lumbar vertbrae mobilization for 4-5 minutes per day and three times a week during 3 weeks period. BIODEX was used to measure muscle strength. All measurements of each subjects were measured at pre-experiment, after 10 day, and post-experiment. Results: The results of this study were summarized as follows; 1. The flexion strength test of control group, lumbar vertebrae mobilization group, lumbar stabilizing exercises group were no significantly differences at pre-experiment and after 10 days(p> .05), however significantly increased post-experiment(p <.05). The result of analyzed effects of flexion strength test was significantly increased accordining to experiment type(p <.05). 2. The extension strength test of control group, lumbar vertebrae mobilization group, lumbar stabilizing exercises group were no significantly differences at pre-experiment and after 10 days(p> .05), however significantly increased post-experiment(p <.05). The result of analyzed effects of extension strength test was significantly increased accordining to experiment type(p <.05). Conclusion: conclusionally these data suggest that a 3-week lumbar stabilizing exercises improved muscle strength. Additional randomized controlled trials to more fully investigate trement effects and factors that may mediate these effect are needed.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.435-438
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• 1990

A new robust stabilizing method of uncertain system is proposed. The model uncertainty is considered to be the system matrix perturbations. The region of perturbed system eigenvalues are estimated by union of the disks which have the constant radius. Full state feedback control matrix which satisfies the new stabilization condition can be obtained by weighted LQ regulator or pole assignment technique.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.1031-1035
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• 2001

In this paper, a robust recursive control approach for nonlinear system, which is based on Lyapunov stability, is proposed. The proposed method can apply to extended systems including cascaded systems and the stability is guaranteed in the sense of Lyapunov. The recursive design procedure so called “robust recursive control approach” is used to find a stabilizing robust controller and simultaneously estimate the uncertainty parameters. First, a nonlinear model with uncertainties whose bounds are unknown is derived. Then, unknown bounds of uncertainties are estimated. By using these estimates, the stabilizing robust controller is updated at each step. This approach is applied to the pitch autopilot design of a nonlinear missile system and simulation results indicate good performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.567-575
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• 2008

Transient security assessment(TSA) is becoming an essential requirement not only for security monitoring but also for stabilizing control of power systems under new electricity environments. It has already been pointed out that fast transient stability study is an important part for monitoring and controlling system security. In this paper, we discuss an energy function method for stabilizing control of transiently unstable systems by introducing generator tripping system to enhance the transient stability of power systems. The stabilization with less tripped power can be obtained by tripping the generators faster than out-of-synchronism relay. Fast transient stability assessment based on the state estimation and direct transient energy function method is an important part of the stabilizing scheme. It is possible to stabilize the transiently unstable system by tripping less generators before the action of out-of-synchronism relay, especially when a group of generator are going to be out-of-synchronism. Moreover, the amount of generator output needed for tripping can be decided by Transient Energy Function(TEF) method. The main contribution of this paper is on the stabilizing scheme which can be running in the Wide Area Control System.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.310-313
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• 1993

A design of stabilizing supervisory controller for discrete event dynamic systems(DEDS) is investigated in this paper. The notion of system stability is introduced for the supervisory control and the stable behavior is defined. A framework of stabilizing supervisory controller, which controls a given system to have stable behavior. is formulated and a design method is proposed for the stabilizing, supervisory controller.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.364-368
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• 1994

Algebraic matrix Riccati equations of the form, FP+PF$^{T}$ -PRP+Q=0. are analyzed with reference to the stability of closed-loop system F-PR. Here F, R and Q are n * n real matrices with R=R$^{T}$ and Q=Q$^{T}$ .geq.0 (nonnegative-definite). Such equations have been playing key roles in optimal control and filtering problems with R .geq. 0. and also in the solutions of in H$_{\infty}$ control problems with R taking the form R=H$_{1}$$^{T}$ H$_{1}$-H$_{2}$$^{T}$ H$_{2}$. In both cases an existence of stabilizing solution, i.e. the solution yielding asymptotically stable closed-loop system, is an important problem. First, we briefly review the typical results when R is of definite form, namely either R .geq. 0 as in LQG problems or R .leq. 0. They constitute two extrence cases of Riccati to the cases H$_{2}$=0 and H$_{1}$=0. Necessary and sufficient conditions are shown for the existence of nonnegative-definite or positive-definite stabilizing solution. Secondly, we focus our attention on more general case where R is only assumed to be symmetric, which obviously includes the case for H$_{\infty}$ control problems. Here, necessary conditions are established for the existence of nonnegative-definite or positive-definite stabilizing solutions. The results are established by employing consistently the so-called algebraic method based on an eigenvalue problem of a Hamiltonian matrix.x.ix.x.