• Journal of the Korean Society for Precision Engineering
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• v.12 no.6
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• pp.120-127
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• 1995

A nonlinear empirical state-space model of the Artificial Neural Network(ANN) has been developed. The nonlinear model structure incorporates characteristic, so as to enable identification of the transient response, as well as the steady-state response of a dynamic system. A hybrid feedfoward/feedback neural network, namely a Local Time Delayed Recurrent Multi-layer Perception(RMLP), is the model structure developed in this paper. RMLP is used to identify nonlinear dynamic system in an input/output sense. The feedfoward protion of the network architecture provides with the well-known curve fitting factor, while local recurrent and cross-talk connections provides the dynamics of the system. A dynamic learning algorithm is used to train the proposed network in a supervised manner. The derived dynamic learning algorithm exhibit a computationally desirable characteristic; both network sweep involved in the algorithm are performed forward, enhancing its parallel implementation. RMLP state-space and its associate learning algorithm is demonstrated through a simple examples. The simulation results are very encouraging.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.156-163
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• 2022

Loss of leg muscle and muscle weakness, which are caused by aging, affect muscle function and sense of balance. As a way of preventing seniors from falling, we developed the idea of wearing functional supporters based on graduated compression technique and in the form of a taping supporter. Their impact on power, sense of balance, overcoming fatigue, and subjective wearing sensation was investigated. The following results were obtained. After wearing functional compression supporters, body temperature increased from 24.5 ± 0.5℃ to 26.3 ± 0.6℃. Calf size, which assesses the level of edema, decreased from 26.1 ± 1.8cm to 25.7 ± 1.8cm. The result of dynamic balance test, which helps estimate the fall prevention effect, increased from 6.4 ± 0.9sec to 7.1 ± 0.6sec. Lactate level, which indicates the level of fatigue, decreased from 8.1 ± 0.6mmol/L to 7.3 ± 0.8mmol/L. Standing long jump record, which assesses power, increased from 110.1 ± 3.1cm to 112.0 ± 2.8cm. Standing on one leg with eyes closed, which assesses sense of balance, increased from 4.2 ± 1.1sec to 6.5 ± 0.8sec. Ankle angle, which assesses joint stability, increased from 75.3 ± 4.0° to 80.1 ± 1.7°. In metabolism and physical performance testing, which assesses keep, the score increased from 26.3 ± 1.7 to 28.8 ± 1.2. Muscle supporting score, which assesses joint stability, increased from 7.3 ± 0.6 to 7.8 ± 0.4. In the category of body type, which assesses wearing sensation and body shaping function, the score increased from 5.7 ± 1.4 to 6.4 ± 1.2

• Proceedings of the ESK Conference
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• 1993.10a
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• pp.113-123
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• 1993

In a sensory evaluation, the data obtained by a result of evaluation have a wide dispersion and fuzziness because human sense organ is used as a means of measuring sensation instead of measuring instruments. These dispersion and fuzziness are caused by all kinds of time error and have a great influence on a sensory evaluation, but most of previous papers don't deal with these time errors. In this study, a comparative judgement capacity of an evaluator is discriminated by means of the eigen-structure analysis on the premise that evaluation value of sensory evaluators obtained by a paired-comparison become different by the order of sample presentation

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.900-902
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• 1997

Stabilization of Power systems is investigated using a proportional-integral power system stabilizer(PI PSS). Time division PI PSS is examined in this paper. Two approaches are presented for determining the optimal stabilizer gains of the proposed PI PSS. Simulation results show that the proposed PI PSS yields better system dynamic performance and stability than the sub-optimal stabilizer in the sense of having greater damping in response to a step disturbance.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.03a
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• pp.39-42
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• 1998

This paper proposes an adaptive fuzzy control scheme for a class of continuous-time nonlinear dynamic systems for which an explicit linear parameterization of the uncertainty is either unknown or impossible. In order to improve robustness under approximation errors and disturbances the proposed scheme includes deadzone in adaptation laws which varies its size adaptively. The assumption of known bounds on the approximation errors and disturbances is not required since those are estimated using adaptation laws. The overall adaptive scheme is proven to guarantee uniform ultimate boundedness in the Lyapunov sense.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12B
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• pp.1996-2002
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• 2000

This paper investigates a priority scheme for IEEE 802.11 Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) protocol in order to provide short access times for priority frames (e.g. time-deadline traffic) even when the overall traffic on the wireless channel is heavy. Under the compatibility constraint for the IEEE 802.11 wireless LANs, two priority systems are simulated: no priority (current IEEE 802.11 standard) for time-deadline traffics and dynamic time-deadline priority. We evaluate algorithms to improve the time-deadline traffic performance using discrete event simulation (DES)

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.29-32
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• 2002

In this paper the wheeled mobile robot is studied. The kinematic and dynamic modeling of the robot is presented via LPD(Linear Parameter Dependent) framework. A path-planning algorithm which is optimized in the sense of robot mobility and distance is presented. And by using PI controller we show that the presented algorithm and model is work very well in the computer simulation and experiment.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.284-284
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• 2000

In adaptive fuzzy control systems. fuzzy systems are used to approximate the unknown plant nonlinearities. Until now. most of the papers in the field of controller design for nonlinear system using fuzzy systems considers the affine system with fixed grid-rule structure based on system state availability. This paper considers observer-based nonlinear controller and dynamic fuzzy rule structure. Adaptive laws for fuzzy parameters for state observer and fuzzy rule structure are established so that the whole system is stable in the sense of Lyapunov.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.497-504
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• 2006

This paper presents a new technique that derives the dynamic acceleration bounds of multiple cooperating robot systems from given individual torque limits of robots. A set of linear algebraic homogeneous equation is derived from the dynamic equations of multiple robots with friction contacts. The mobility of the robot system is analyzed by the decomposition of the null space of the linear algebraic equation. The acceleration bounds of multiple robot systems are obtained from the joint torque constraints of robots by the medium of the decomposed null space. As the joint constraints of the robots are given in the infinite norm sense, the resultant acceleration bounds of the systems are described as polytopes. Several case studies are presented to validate the proposed method in this paper.

• Structural Engineering and Mechanics
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• v.31 no.6
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• pp.737-749
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• 2009

The problem of estimating the dynamic response of a distributed parameter system excited by a moving vehicle with random initial velocity and random vehicle body mass is investigated. By adopting the Galerkin's method and modal analysis, a set of approximate governing equations of motion possessing time-dependent uncertain coefficients and forcing function is obtained, and then the dynamic response of the coupled system can be calculated in deterministic sense. The statistical characteristics of the responses of the system are computed by using improved perturbation approach with respect to mean value. This method is simple and useful to gather the stochastic structural response due to the vehicle-passenger-bridge interaction. Furthermore, some of the statistical numerical results calculated from the perturbation technique are checked by Monte Carlo simulation.