• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.8-15
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• 2015

This paper includes a method for estimating the parameter of a synchronous generator and exciter using the modified particle swarm optimization. A solid round rotor synchronous generator and exciter have been modeled with the saturation function. They are regarded as state of being cooperative to a infinite bus. The behavior characteristic of all particles assigned to a parameter needs to be reflected in the PSO algorithm to fine out more close result to the optimal solution. The results of the simulation to estimate the parameters of the synchronous generator and exciter in the modified PSO algorithm are described.

• Journal of Information Processing Systems
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• v.16 no.2
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• pp.394-405
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• 2020

The parameters of transmission lines have an influence on the electromagnetic environment surrounding the line. This paper proposes a method based on phasor measurement unit (PMU) and supervisory control and data acquisition (SCADA) to achieve online estimation of transmission line full parameters, such as resistance, reactance and susceptance. The proposed full parameter estimation method is compared with the traditional method of estimating resistance independently based on SCADA system. Then, the electromagnetic environment is analyzed based on the different parameter estimation methods. The example results illustrate that online estimation of transmission line full parameters is more accurate in the analysis of electromagnetic environment, which further confirms its necessity and significance in engineering application.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.8-13
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• 2008

The paper proposes a model-based measurement of unsteady flow rate by using distributed parameter pipeline model and the measured pressure values at two distant points along the pipeline. The distributed parameter model of hydraulic pipeline is applied with consideration of frequency dependent viscosity friction and unsteady velocity distribution at a cross section of a pipeline. By using the self-diagnostics functions of the measurement method, the validity is investigated by comparison with the measured and estimated pressure and flow rate wave forms at the halfway section on the pipeline. The results show good agreement between the estimated flow rate wave forms and theoretical those under unsteady laminar flow conditions. The method proposed here is useful in estimating unsteady flow rate through an arbitrary cross section in hydraulic pipeline and components without installing an instantaneous flowmeter.

• Journal of KSNVE
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• v.9 no.5
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• pp.891-898
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• 1999

The purpose of Superconducting Magnetic Bearing Flywheel Energy Storage System (SMB-FESS) is to store unused nighttime electricity until it is needed during daytime. An analytical model of the SMB-FESS is necessary to identify the system behavior. At first, we have to model the superconducting magnetic bearing. Modeling the SMB is same as estimating the bearing parameter. The theoretical modal parameter is calculated through the equation of motion and the experimental modal parameter is estimated through the impact testing (modal testing). The bearing parameter is searched by using the non-linear least square method until the theoretical result corresponds to the experimental result. The suggested modeling method is verified by comparing experimental and analytical frequency response function.

• Structural Engineering and Mechanics
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• v.56 no.3
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• pp.423-442
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• 2015

This study examines the wavelet transform for output-only system identification of ambient excited engineering structures with emphasis on its utilization for modal parameter estimation of high-order and closely-spaced modes. Sophisticated time-frequency resolution analysis has been carried out by employing the modified complex Morlet wavelet function for better adaption and flexibility of the time-frequency resolution to extract two closely-spaced frequencies. Furthermore, bandwidth refinement techniques such as a bandwidth resolution adaptation, a broadband filtering technique and a narrowband filtering one have been proposed in the study for the special treatments of high-order and closely-spaced modal parameter estimation. Ambient responses of a 5-story steel frame building have been used in the numerical example, using the proposed bandwidth refinement techniques, for estimating the modal parameters of the high-order and closely-spaced modes. The first five natural frequencies and damping ratios of the structure have been estimated; furthermore, the comparison among the various proposed bandwidth refinement techniques has also been examined.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.718-722
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• 2014

A method for estimating the cylindrical shape of a sound radiator is presented. It assumes that sound field can be measured by a linear array. A sound field, due to the radiator vibrating with uniform velocity, can be determined by its shape, size, and orientations. Measured data also can be varying from the array's position. To predict the shape of radiators from these measured data, mathematical relation between geometric parameter and measured information is needed. Assume that a radiator is cylinder, the magnitude and phase of measured pressure is related with the length and diameter of radiator, respectively. In this paper, the method for estimating length and shape of a finite cylinder by using its radiated pressure is proposed and verified through experiment.

• Membrane Journal
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• v.26 no.3
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• pp.187-196
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• 2016

Pressure-assisted forward osmosis (PAFO) process has recently been under spotlight for its potential to improve forward osmosis (FO) process performance by applying low hydraulic pressure on the feed side. Structure parameter, one of the governing factors in estimating water flux and solute flux across FO membranes in the solution-diffusion model (S-D model), determines solute resistivity in FO and PAFO processes. This study aims to estimate the trend of structure parameter change with respect to varying additional hydraulic pressure condition in PAFO.

• Kyungpook Mathematical Journal
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• v.50 no.2
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• pp.307-314
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• 2010

By introducing a homogeneous kernel of 0-degree with an independent parameter and estimating the weight coefficient, a bilateral form of the Hilbert-type series inequality with a best constant factor is established.

• Journal of the Korean Statistical Society
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• v.27 no.2
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• pp.221-235
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• 1998

Suppose that an observed process can be written as the additive model of the signal process and the noise process with unknown parameters. In practice the signal process is not directly observed. We consider the problem of estimating parameter from the observation process using the quasi-likelihood method.

• Kyungpook Mathematical Journal
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• v.49 no.2
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• pp.393-401
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• 2009

By introducing a parameter and estimating the weight coefficient, we obtain a new Hilbert-type integral inequality with a composite kernel and a best constant factor. As applications, we also consider its equivalent forms and reverse forms.