• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.9-12
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• 2013

Current-voltage characteristic models of superconducting material are suggested by many researchers. These current-voltage characteristic models are important because they can be used for design or simulation of superconductor devices. But widely used current-voltage models of superconductor wire still have some limitations. For example, a standard E-J power model has no parameters related with stabilizer's resistance in superconductor wire. In this paper, a current-voltage characteristic modeling method for high temperature superconductor (HTS) tape with considering the effect of stabilizer is introduced. And a current-voltage characteristic of a HTS tape is measured under different stabilizer conditions. Those measured current-voltage characteristics of the HTS tape modeled with proposed modeling method and the modeling results are compared.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.128-130
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• 2002

This paper describes the operating characteristic analysis of magnetic actuator that is used in breaker using 3-D axisymmetry finite element method. To analyze the operating characteristic of magnetic actuator for configuration change is designed an A, B model and C. Also, For Transient analysis of Electromagnetic system is considered Non-linear characteristic for magnetizing of iron. The analysis results of A, B model and C for magnetic actuator compared with those characteristic respectively.

• Journal of computational fluids engineering
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• v.5 no.1
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• pp.43-59
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• 2000

Characteristic boundary conditions are discussed in conjunction with a flux-difference splitting formulation as modified from Roe's linearization. Details of how one can implement the characteristic boundary conditions which are made compatible with the interior point formulation are described for different types of boundaries including subsonic outflow and adiabatic wall. The validity of boundary conditions are demonstrated through computation of transonic airfoil, supersonic ogive-cylinder, hypersonic cylinder, and S-duct internal flows. The computed wall pressure distributions are compared with published experimental and computed data. Objectives of this paper are thus to give insight of formulation procedure of a flux-difference splitting method and to pave ways for other users to adopt present boundary procedure on their numerical methods.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.531-536
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• 2003

In order to control the railway noise. we should know the radiation characteristic of the noise during the train passage Generally, the railway noise sources for conventional trains are classified by the rolling noise and power unit noise in tangent track. In this Paper. we describe on a train model that is considered to be a row of point sources to calculate the radiation characteristic The calculation results are compared with short distance measurement of three kinds of trains (EMU, Mookungwha, Saemaul). It is shown that the radiation characteristic of the rolling noise that is major noise source of electric multiple unit is dipole type. We know that characteristic of the engine noise is radiated as the cosine type.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.10
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• pp.870-879
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• 2005

This paper presents that a transient response can be characterized by certain parameters which are correlated to characteristic polynomial coefficients. These are characteristic ratios and characteristic pulsatances by P. Naslin [4]. We have developed an approach to control directly the transient response. Firstly, speed of the response can be controlled by reconstruction form via multipliable characteristic pulsatances. Secondly, overshoot is controlled by reconstruction form via multipliable characteristic ratios. These formulas can be independently characterized by the system overshoot and the response time to a step input.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.99-110
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• 1996

In this paper, the analysis o fthe electric field distribution for TEM cell which is matched iwth 50 is performed, and the relations of variables for characteristic impedance are derived. Quasi-static approximations are used to calculate the fiedl strength of the internal field of TEM cell. The results of the improved method for analysis of the electric field is compared with that of R.J. Spigel. and the improved method for characteristic impedance and the results of numerical analysis are shown.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.6
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• pp.153-161
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• 2003

The purpose of this paper is to investigate the soil-water characteristic curves for an unsaturated soil. To this ends, a series of suction measured test was conducted on the selected 4 kinds of soils taken from different sites of Korea, using modified pressure plate apparatus. Form the test results, the water contents, degree of saturation and volumetric water contents were analyzed with the suction. And the soil-water characteristic curves of unsaturated soil were drawn from the test results for various factors. The characteristic curves drawn with water content vs matric suction were classified certainly the difference in wet side but were not classified in dry side. The characteristic curves drawn with degree of saturation vs matric suction for unsaturated soil were shown the opposite inclination as compared with the former curve. But the characteristic curve with volumetric water content vs matric suction was described suitably not only in wet side condition but also in dry side. And it was found that the volumetric water contents of loose soil was high at the initial condition but that of dense soil was high at final condition (dry side).

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.136-141
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• 1998

In order to enhance the performance of a CELP coder at low bit rates, it would be necessary to make the CELP excitation have the peaky pulse characteristic. In this paper we introduce an excitation signal with peaky pulse characteristic. It is obtained by using a two-tap pitch predictor. Samples of the signal have different gains according to their amplitudes by the predictor. In voiced sound the signal has the desirable peaky pulse characteristic, and its periodicity is well reproduced. Particularly, peaky pulses at voiced onset and a burst of plosive sound are clearly reconstructed.

• Communications of the Korean Mathematical Society
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• v.22 no.4
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• pp.587-596
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• 2007

In this paper, we study two-phase flow models. The chunk mix model of the two-phase flow equations is analyzed by a characteristic analysis. The model discussed herein has real characteristic values for all physically acceptable states and except for a set of measure zero has a complete set of characteristic vectors in state space.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.236-243
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• 2008

This paper analyses magnetic flux saturation of matching transformer considering characteristic of dynamic voltage restorer(DVR) system to solve voltage sags which are considered the dominant disturbances affecting power quality. This DVR consist of PWM inverter to inject arbitrary voltage, LC low pass filter and matching transformer for isolation and grid connection. However, the matching transformer has an excess of inrush current by magnetic flux saturation in the core of transformer. Due to this inrush current, the rating of matching transformers is double for needed nominal rating for protection of DVR. Therefore, in this paper, an advanced modeling method of magnetic flux saturation is used to analyze a magnitude and characteristic of magnetizing current. Simulation and experimental results considering characteristic of DVR system are provided to demonstrate the validity of the proposed analysis method.