• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2212-2220
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• 2020

Background: Repetitive damage to the ankle joint causes chronic ankle instability, and studies comparing the effects of exercise in open and closed chains as a treatment method are very rare. Objectives: To investigate the effects of open and closed kinetic exercises on muscle activity and dynamic balance of ankle joint in adults with chronic ankle instability. Design: Single-blind randomized controlled trial. Methods: The selected 30 subjects are randomly divided into open kinetic chain exercise experimental group (EGI, n=10), closed kinetic chain exercise experimental group (EGII, n=10), and stretching control group (CG, n=10). Open and closed kinetic exercises lasted 30 minutes three times a week for six weeks and stretching exercises performed four actions for 20 seconds and five sets. The measurement tools using surface electromyography to measure muscle activity in the ankle joint. The dynamic balance of the ankle was evaluated using the Y-Balance test. Results: Following the intervention, closed and open kinetic chain exercise group showed significant difference in tibialis anterior and gastrocnemius muscle activity and dynamic balance (P<.05). However, no significant difference in tibialis anterior and gastrocnemius muscle activity and dynamic balance between closed and open kinetic chain exercise group (P<.05). Conclusion: This study provides evidence that closed and open kinetic chain exercise can be presented as an effective exercise for the muscle activity of ankle muscle and dynamic balance of the subject with chronic ankle instability.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1256-1263
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• 2015

A novel vector control strategy for a permanent magnet synchronous motor (PMSM) based on the kinetic energy stored in the rotor is proposed in this paper. The novel strategy is composed of two closed loops, in which the current loop is the inner loop, and the kinetic energy serves as the outer loop. The theoretical basis and the design procedure of the two loops are given. The feasibility of the proposed control strategy is verified by experimental results. When compared with traditional vector control strategies, the proposed vector control strategy based on energy feedback has better dynamic performance. In addition, an effective estimation solution for the load variation is put forward.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.345-350
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• 2015

Purpose: This study was conducted to determine the effects of ankle joint position during closed kinetic chain (CKC) exercise on knee extensor strength and balance in patients with chronic stroke. Methods: Sixteen patients with chronic stroke participated in the study. Participants were randomly assigned to two groups: $15^{\circ}$ ankle joint plantar flexion group (n=8) and ankle joint neutral group (n=8) during CKC exercise. All participants underwent conventional physical therapy for 30 minutes. In addition, the experimental group ($15^{\circ}$ ankle joint plantar flexion group) and control group (ankle joint neutral group) participated in a 20-minute CKC exercise program. In both groups exercise was performed three times a week for four weeks. Outcomes including knee extensor strength and balance ability (Five times sit-to-stand test, Timed up and go test, and Balancia) were measured before and after exercise. Results: Significant differences in knee extensor strength and balance ability were observed between pre- and post-exercise in all groups (p<0.05). The improvement of knee extensor strength and dynamic balance was significantly higher in the experimental group than in the control group (p<0.05). Conclusion: These findings demonstrated that $15^{\circ}$ ankle joint plantar flexion during closed kinetic chain exercise is effective in improvement of knee extensor strength and dynamic balance in patients with chronic stroke.

• The Journal of Korea Robotics Society
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• v.12 no.3
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• pp.339-349
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• 2017

In this paper, we present a finite-time sliding mode control (FSMC) with an integral finite-time sliding surface for applying the concept of graph theory to a distributed wheeled mobile robot (WMR) system. The kinematic and dynamic property of the WMR system are considered simultaneously to design a finite-time sliding mode controller. Next, consensus and formation control laws for distributed WMR systems are derived by using the graph theory. The kinematic and dynamic controllers are applied simultaneously to compensate the dynamic effect of the WMR system. Compared to the conventional sliding mode control (SMC), fast convergence is assured and the finite-time performance index is derived using extended Lyapunov function with adaptive law to describe the uncertainty. Numerical simulation results of formation control for WMR systems shows the efficacy of the proposed controller.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.134-137
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• 2001

The cure kinetics of a cycloalipatic epoxy / anhydride / Co(II) system for a no-flow underfill encapsulant, has been studied by using a differential scanning calorimetry(DSC) under isothermal and dynamic conditions over the temperature range of $160^{\circ}C ~220^{\circ}C$. The kinetic analysis was carried out by fitting dynamic/isothermal heating experimental data to the kinetic expressions to determine the reaction parameters, such as order of reaction and reaction constants. Diffusion-controlled reaction has been observed as the cure conversion increases and successfully analyzed by incorporating the diffusion control term into the rate equation. The prediction of reaction rates by the model equation corresponded well to experimental data at all temperature.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.5
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• pp.358-363
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• 2000

In this paper, a voltage equations, a thrust force equations and kinetic equation are derived from the basic structure of a 2-phase hybrid type linear stepping motor(HLSM). And a micro-stepping method in order to eliminate effectively the resonant phenomena and to increase the positional resolution of the HLSM was proposed. The proposed micro-stepping method can divide one step into the maximum 128 micro-steps under simple control system. The dynamic characteristics of proposed micro-stepping method were analyzed by the ACSL(Advanced Continuous Simulation Language) with the voltage equations, the thrust force equations and the kinetic equation, and were measured by laser experimental system. As the result, the justice of theory was confirmed, and the resonant phenomena, the positional resolution and dynamic thrust were improved by the proposed micro-stepping method.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.48-55
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• 2001

An accumulator in hydraulic systems stores kinetic energy during braking action, and then that control hasty surge pres-sure. This study suggests a method to select the capacity of accumulator to control surge pressure to a desired degree. The selection method is based upon a trial and error approach and computer simulation. A mathematical dynamic model of the system was derived and the parameters in the model were identified from experimental data. A series of computer simulation were done for the brake action. The results of the simulation work were compared with those of experiments. These results of the computer simular-tion and experiments show that the proposed method can be applied effectively to control the surge pressure of the hydraulic regenerative brake systems.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1611-1616
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• 1991

A high power stewart platform is designed and manufactured to simulate the 6 degrees of freedom motion of moving vehicle. This paper describes the design of such a motion system including kinematic and kinetic analysis, real time servo control mechanical and hydraulic system configuration, and techniques of regeneration of test records. Discussions are also presented for an algorithm called remote parameter control, which has been developed to compensate the dynamic delay of the electro-hydraulic servo actuators and the nonlinearities of stewart platform.

• Architectural research
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• v.8 no.2
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• pp.37-42
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• 2006

Starting from the quadratic optimal control algorithm, this study obtains the relation of the performance index for constrained systems and Gauss's principle. And minimizing a function of the variation in kinetic energy at constrained and unconstrained states with respect to the velocity variation, the dynamic equation is derived and it is shown that the result compares with the generalized inverse method proposed by Udwadia and Kalaba. It is investigated that the responses of a 10-story building are constrained by the installation of a two-bar structure as an application to utilize the derived equations. The structural responses are affected by various factors like the length of each bar, damping, stiffness of the bar structure, and the junction positions of two structures. Under an assumption that the bars have the same mass density, this study determines the junction positions to minimize the total dynamic responses of the structure.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1021-1024
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• 1993

System identification is a major component for a control system. In biosystems, which is nonlinear and dynamic, precise identification would be very helpful for implementing a control system. It is difficult to precisely identify such non-linear systems. The measurable data on products from 2,3-butanediol fermentation could not be included in a process model based on kinetic approach. Meanwhile, a predictive capability is required in developing a control system. A neural network (NN) dynamic identifier with a by/(1＋ t ) transfer function was therefore designed being able to predict this fermentation. This modified inverse NN identifier differs from traditional models in which it is not only able to see but also able to predict the system. A moving window, with a dimension of 11 and a fixed data size of seven, was properly designed. One-step ahead identification/prediction by an 11-3-1 BPNN is demonstrated. Even under process fault, this neural network is still able to perform several-step ahead prediction.