• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.601-606
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• 1986

In this paper, two methods of power circuit simulation is described in order to obtain the back data for design of current source inverter. One is steady-state analysis by differential equations during the various operating modes. Another method uses switching function, which represents the switching pattern of inverter, and direct-guadrature model of induction motor. The results of digital computer simulation by two methods are compared with the results of laboratory test.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.546-549
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• 2002

In this paper, a simulation system, which is almost same with the real motor-mechanical control system, is established. The real system is identified by using the data from DSP(TMS320F240). The RLS(Recursive Least Square) algorithm is used for the identification and MATLAB Simulink program is used for simulation. The exact simulation system obtained by using the proposed method is very useful for analysis and design of motor-mechanical control systems.

• IE interfaces
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• v.9 no.1
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• pp.25-40
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• 1996

It is a time-consuming work to develop a control software for AGVS considering different physical arrangements and transport requirements in automated manufacturing systems. An integrated software environment is suggested to support the development of the control software by utilizing a simulation software which imitates changes in the target shop floor. First, the basic functions of the controller are defined and interactions between modules(function) are identified to enhance the modularity of the controller. Prototype software is developed for the simulation station and the control station, respectively, which are connected with each other by a communication link to transmit predefined messages.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.153-156
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• 2001

We have developed CNS(Compact Nuclear Simulator) which can be used for the fundamental training of the nuclear power plant operators. The application software for CNS consists of simulation engine(analyzer code), instructor station software, and man-machine interface software. Each application software is regarded as one black box and the communication of black boxes is performed by the predefined shared memory variables. In this paper, we discuss our experience for CNS development.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.62-62
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• 1999

In this paper, we propose a new technique of estimating tail of steady-state queue length distribution; Pr(Q>q), fo ATM multiplexer. Pr(Q>q) is a fundamental measure of network congestion. Assessing Pr(Q>q) properly is crucial for design and control of ATM networks. Data traffic pattern of high-speed networks is highly correlated and bursty. Estimating Pr(Q>q) is very difficult because of correlation and burstiness. We estimate entropy(rate-function) using large deviation principles and threshold bootstrap. Simulation studies are conducted to compare the performance of an existing method and our new method.

• Journal of the Semiconductor & Display Technology
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• v.3 no.3
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• pp.27-29
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• 2004

The responses of hypothetical silicon nanotubes under torsion have been investigated using an atomistic simulation based on the Tersoff potential. A torque, proportional to the deformation within Hooke's law, resulted in the ribbon-like flattened shapes and eventually led to a breaking of hypothetical silicon nanotubes. Each shape change of hypothetical silicon nanotubes corresponded to an abrupt energy change and a singularity in the strain energy curve as a function of the external tangential force, torque, or twisted angle. The dynamics of silicon nanotubes under torsion can be modelled in the continuum elasticity theory.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.109-111
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• 2008

PWM IC modeling for single and double output type is performed for converter simulation. The function and performance of a specific IC, UC 3525, is realized in model for real case simulation.

• Journal of the Korea Society for Simulation
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• v.10 no.3
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• pp.31-46
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• 2001

Repeated measurements on units under different conditions are common in biological and biomedical studies. In a number of growth and pharmacokinetic studies, the relationship between the response and the covariates is assumed to be nonlinear in some unknown parameters and the form remains the same for all units. Nonlinear random coefficient models are used to analyze such repeated measurement data. Extended least squares methods are proposed in the literature for estimating the parameters of the model. However, neither objective function has closed form expression in practice. This paper proposes Monte Carlo methods to estimate the objective functions and the corresponding estimators. A simulation study that compare various methods is included.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.6
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• pp.706-713
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• 1985

It is clear that when the amplitude of grinding chatter increases enough the contact between grinding wheel and workpiece cannot be sustained and the loss of contact occurs during a period of grinding chatter. In this paper the behavior of nonlinear grinding chatter due to the loss of contact has been studied. A nonlinear grinding chatter loop is developed where the loss of contact is considered as a nonlinear element of asymmetrical gain. The analysis is carried out in the time domain by numerical simulation and also in the complex domain by use of describing function method. The results show that two typical patterns of nonlinear grinding chatter can originate from the nonlinearity. One is an irregular chatter frequency at starting stage decreases to the natural frequency of grinding structure while the chatter amplitude increases and decreases repeatedly. The other is a limit cycle chatter of which the amplitude and frequency converge to constant and remain. This nonlinear behavior of grinding chatter has been well analyzed by the describing function method and confirmed by the numerical simulation.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.268-284
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• 2010

The purpose of this study was to evaluate the effects of horseback riding simulation training(HRST) on gross motor function of children with cerebral palsy. Twenty-four children with cerebral palsy participated were divided into two groups randomly. Control group and experimental group both received 30 minutes of regular neuro-rehab exercises for three times a week per twelve weeks, but experimental group received additional 15 minutes of the HRST. Gross Motor Function Measure(GMFM) was used to evaluate the changes before and after HRST. Normalized GMFM scores were compared using Mann-Whitney U test, statistical significance was set at a=.05. The results were as followings: First, in each compared before and after the experiment, the control group showed significantly increased GMFM score in dimensions A and B. The experimental group showed significant increasing in all dimensions of GMFM test. Second, the experimental group showed significant differences comparing to control group in dimensions C, D and E of GMFM test. Consequently, HRST should be considered as a therapeutic method for physical therapy for the children with cerebral palsy to improve the functional movements.