• Journal of the Korean Chemical Society
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• v.60 no.3
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• pp.163-168
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• 2016

We summarize the discrete variable representation method which is a simple numerical method enabling us to calculate the vibrational energies and wave functions of anharmonic oscillators. The ranges of its parameters well-performing for the calculation of fundamental and overtone transition energies are predicted by analyzing the model of Morse oscillator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1047-1052
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• 2017

In this paper, the calculation torque using the d-q axis has advantage like faster execution time. However, the torque ripple can't be considered in the torque calculation using d-q axis equivalent circuit because the time-dependent component is removed. When d-q transformation was performed, it was founded that some parameters has some characteristics. These characteristics were considered for representing torque ripple. The calculation with d-q axis transformation and Finite Element Analysis(FEA) were performed, and the results were compared. As a result, it was validated that the calculated torque can be expressed with ripple.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.159-164
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• 2013

Difficulty of torque measurements in high-speed permanent magnet (HSPM) motors has necessitated the development of improved torque calculations. Hence, this paper presents an analytical torque calculation of a high speed permanent magnet (HSPM) motor based on the power factor angle. On the basis of analytical magnetic field solutions, the equations for circuit parameters such as back-emf and synchronous inductance are derived analytically. All analytical results are validated extensively by non-linear finite element (FE) calculations and measurements. The internal angle (${\delta}$) between the back-emf and the phase current is calculated according to the rotor speed by using analytical circuit parameters and the measured power factor because this angle is not measured but estimated in case of sensorless drive of the HSPM motor, significantly affecting torque calculation. Finally, the validity of the torque analysis method proposed in this paper is confirmed, by showing that the torque calculated on the basis of the internal angle is in better agreement with the measurements.

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.282-289
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• 2010

A Thomson coil type actuator is applied as the driving unit in an arc eliminator system. To eliminate the arc efficiently, the speed of the actuator is required as fast as possible with certain limit of the exciting current. Therefore, the dynamic characteristics of the Thomson coil type actuator should be analyzed in an effective way. In this paper, a novel solving technique has been developed based on the equivalent circuit model which is set up by dividing the conducting plate into multi segments. To guarantee the calculation accuracy and improve the calculation efficiency, an adaptive refinement algorithm is suggested based on the field continues condition. The proposed method has been verified by the FEM calculation and experiment. The influence of circuit and plate parameters to the performance of the actuator is also investigated, from which a reasonable set of parameters can be found.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.64-69
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• 1997

The code WIMS-AECL has been used for the lattice analysis of DUPIC fuel. The lattice parameters calculated by the code is sensitive to the choice of number of parameters, such as the number of tracking lines, number of condensed groups, mesh spacing in the moderator region, other parameters vital to the calculation of probabilities and burnup analysis. We have studied this sensitivity with respect to these parameters and recommend their proper values which are necessary for carrying out the lattice analysis of DUPIC fuel.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.738_739
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• 2009

This paper describes the calculation of the equivalent circuit parameters according to the slip in squirrel-cage induction motor. Recently, the induction motor is demanded of the various operation condition. In order to acquire the accurate characteristic for the operation condition of the motor, equivalent circuit parameters have to be calculated accurately. So the equivalent circuit parameters are computed by using the finite element method, the reliable characteristic analysis is carried out by application of the parameter to the equivalent circuit analysis. From the analysis result using this combined equivalent circuit and finite element method is compared with the experimental results by a detailed equivalent circuit, the validity of the method is proved.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.171-178
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• 2002

Numerical simulations of the condition in the iron ore sintering bed are performed for various parameters. The sintering bed is modelled as an unsteady one-dimensional progress of solid material, containing cokes and iron ore. Bed temperature, solid mass and gas species distributions are predicted for various parameters of moisture contents, cokes contents and air suction rates, along with the various particle diameters of the solid for sensitivity analysis. Calculation results show that influences of these parameters on the bed condition should be carefully evaluated for achievement of the self-sustaining combustion without the high temperature section, which can cause the excessive melting in the bed. It suggests that the model should be extended to consider the bed structural change and multiple solid phase, which can treat the inerts and fuel particles separately.

• Journal of Welding and Joining
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• v.10 no.2
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• pp.32-42
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• 1992

A method of optimization of process parameters in Arc Welding has been discussed in this paper. The method of investigation is based on the numerical calculation of weld bead by a finite element method and non-linear optimization technique is applied to estimated the optimization process parameters from the numerical calculation. The common package program(ANSYS 4.4A) was used to obtain the process parameters for a thin plate arc welding (TIG, CO$_{2}$). The results on some test are satisfactory and the used method of this paper is a useful guide to the optimum welding condition.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.252-256
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• 1999

In this research, the performance predictions of the submersible mixer were investigated. The variation of the performance characteristics by changing the impeller design parameters were discussed through the flow calculation results by using a commercial program, FLUENT. The performance of the submersible mixers is related to the velocity diffusion profiles downstream of the impeller and also the required input motor power to mix the fluid. In this study, the various design parameters such as the number of blade, the hub and tip diameters, the impeller blade profiles and revolution speed of the blades were taken for the fixed values. The blade sweep direction, the chord length distribution along with the radius of the blade and the inlet blade angle were changed to make different testing models. The flow calculation results show the effect of the changed design parameters on the performance of the submersible mixers and also give some helpful information for designing more efficient submersible mixers.

• Bulletin of the Korean Chemical Society
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• v.12 no.2
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• pp.228-238
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• 1991

Generalized multichannel quantum defect theory [C. H. Greene et al. Phys. Rev., A26, 2441 (1982)] is implemented to the vibrational predissociation of triatomic van der Waals molecules. As this is the first one of such an application, the dependences of the quantum defect parameters on energy and radius are examined carefully. Calculation shows that, in the physically important region, quantum defect parameters remain smoothly varying functions of energy for this system as in atomic applications, thus allowing us very coarse energy mesh calculations for the photodissociation spectra. The choice of adiabatic or diabatic potentials as reference potentials for the calculation of quantum defect parameters as done by Mies and Julienne [J. Chem. Phys., 80, 2526 (1984)] can not be used for this system. Physically motivated reference potentials that may be generally applicable to all kinds of systems are utilized instead. In principle, implementation can be done to any other predissociation processes with the same method.