• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.110-116
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• 2017

This paper proposed a new real-time parameter tracking algorithm. Unlike the convenience algorithms, the proposed real-time parameter tracking algorithm can estimate parameters through three-phase voltage and electric current without coordination transformation, and does not need information on magnetic flux. Therefore, it can estimate parameters regardless of the change according to operation point and cross-saturation effect. In addition, as the quasi-real-time parameter tracking technique can estimate parameters through the four fundamental arithmetic operations instead of complicated algorithms such as numerical value analysis technique and observer design, it can be applied to low-performance DSP. In this paper, a new real-time parameter tracking algorithm is derived from three phase equation. The validity and usefulness of the proposed inductance estimation technique is verified by simulation and experimental results.

• Speech Sciences
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• v.9 no.1
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• pp.77-88
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• 2002

Acoustical correlates of stress can be classified as duration, intensity and fundamental frequency. This study examined the acoustical differences in the first two syllables of stressed English words produced by ten American and Korean speakers. The Korean subjects scored very high on the TOEFL. They read at a normal speed a fable from which the acoustical parameters of eight words were analyzed. In order to make the data comparison meaningful, each parameter was collected at 100 dynamic time points proportional to the total duration of the two syllables. Then the ratio of the parameter sum of the first rime to that of the second rime was calculated to determine the relative prominence of the syllables. Results showed that the durations of the first two syllables were almost comparable between the Americans and Koreans. However, statistically significant differences showed up in the diphthong pronunciations and in the words with the second syllable stressed. Also, remarkably high r-squared values were found between pairs of the three acoustical parameters, which suggests that either one or a combination of two or more parameters may account for the prominence of a syllable within a word.

• International Journal of Korean Welding Society
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• v.3 no.1
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• pp.51-56
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• 2003

It is important to evaluate the fracture initiation behaviors of steel structure. It has been well known that the ductile cracking of steel would be accelerated by triaxial stress state. Recently, the characteristics of critical crack initiation of steels are quantitatively estimated using the two-parameters, that is, equivalent plastic strain and stress triaxiality, criterion. This study is paid to the fundamental clarification of the effect of notch radius, which can elevate plastic constraint due to heterogeneous plastic straining on critical condition to initiate ductile crack using two-parameters. Hense, the crack initiation testing were conducted under static loading using round bar specimens with circumferential notch. To evaluate the stress/strain state in the specimens was used thermal elastic-plastic FE-analysis. The result showed that equivalent plastic strain to initiate ductile crack expressed as a function of stress triaxiality obtained from the homogeneous specimens with circumferential notched under static loading. And it was evaluated that by using this two-parameters criterion, the critical crack initiation of homogeneous specimens under static loading.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.328-332
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• 1996

B-ISDN is expected to be a main vehicle of future telecommunications. There has been a series fo studies on the demand and the market prospect of B-ISDN services. It is true, however, that they lacked some economic reality since the price of services has been overlooked which is a critical economic factor. In this study, we analyze some aspects of the tariff system of B-ISDN services. First, we explore and summarize the billing parameters of B-ISDN services from diverse characteristics of services and ATM network. These parameters are essential if the services are to be charged based on usage. Secondly, we discuss what factors be considered in the design fo B-ISDN services tariff systems from various points of view shch as traffic charactristics, information types and connection types, etc. The results of this study will offer fundamental insights in the design of B-ISDN service pricing scheme and provide reference for efficient services providing.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.613-616
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• 2002

Luminance and contrast ratio is one of the most fundamental and important parameters of plasma display panel. Understanding the effects of cell design parameters on the display and background luminance is inevitable for improving the contrast ratio. We report the experimental results on the relationships between cell parameters and contrast ratio of the ac PDP driven by ADS scheme. It was found that the contrast ratio is the most significantly affected by rib height and optimum range of the rib height simultaneously affects the facing discharge during the reset periods, diffusion loss of plasma and shadowing of the visible light emitted from phosphor.

• Journal of Astronomy and Space Sciences
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• v.14 no.1
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• pp.1-17
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• 1997

The results of a restricted numerical simulation for the color gradients within globular clusters have been presented. The standard luminosity function of M3 and Salperter's initial mass functions were used to generate model clusters as a fundamental population. Color gradients with the sample clusters for both King and power law cusp models of surface brightness distributions are discussed in the case of using the standard luminosity function. The dependence of color gradients on several parameters for the simulations with Salpter's initial mass functions, such as slope of initial mass functions, cluster ages, metallicities, concentration parameters of King model, and slopes of power law, are also discussed. No significant radial color gradients are shown to the sample clusters which are regenerated by a random number generation technique with various parameters in both of King and power law cusp models of surface brightness distributions. Dynamical mass segregation and stellar evolution of horizontal branch stars and blue stragglers should be included for the general case of model simulations to show the observed radial color gradients within globular clusters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.68-74
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• 2014

The electrical parameters of soils are highly dependent on the various factors such as types of soil, chemical compositions, moisture content, temperature, frequency, and so on. The analysis of soil parameters is of fundamental importance in design of grounding systems. In this paper, we present the experimental results of frequency-dependent impedance, resistivity, permittivity of soils as functions of types of soil and moisture content. The impedance and resistivity of soils are decreased as the moisture content and the frequency increase. In particular, the variation of the soil resistivity with the frequency is pronounced in the conditions of high resistivity and low moisture content. On the contrary, the permittivity of soils are sharply decreased with increasing the frequency below 10kHz and the frequency-dependent permittivity of soils are highly changed in the conditions of high moisture and low resistivity.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.1-8
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• 2003

In general, the microstructure in thin films was known to evolve in similar manner according to the energy striking the condensing film at similar homologous temperature, Th for the materials of the same crystal structure. The fundamental factors affecting particle energy are a function of processing parameters such as working pressure, bias voltage, target/sputtering gas mass ratio, cathode shape, and substrate orientation. In this study, Al, Cu, Pt films of the same crystal structure of face centered cubic (FCC) have been prepared under various processing parameters. The influence of processing variables on the microstructures and residual stress states in the films has been studied.

• Applied Microscopy
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• v.45 no.3
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• pp.150-154
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• 2015

Negative staining electron microscopy facilitates the visualization of small bio-materials such as proteins; thus, many electron microscopists have used this conventional method to visualize the morphologies and structures of biological materials. To achieve sufficient contrast of the materials, a number of imaging parameters must be considered. Here, we examined the effects of one of the fundamental imaging parameters, electron beam exposure time, on electron densities generated using transmission electron microscopy. A single site of a negatively stained biological sample was illuminated with the electron beam for different times (1, 2, or 4 seconds) and sets of micrographs were collected. Computational image processing demonstrated that longer exposure times provide better electron densities at the molecular level. This report describes technical procedures for testing parameters that allow enhanced evaluations of the densities of electron microscopy images.

• Advances in aircraft and spacecraft science
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• v.4 no.3
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• pp.269-280
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• 2017

The natural vibration analysis of microbeams resting on visco-Pasternak's foundation is presented. The thermoelasticity theory of Green and Naghdi without energy dissipation as well as the classical Euler-Bernoulli's beam theory is used for description of natural frequencies of the microbeam. The generalized thermoelasticity model is used to obtain the free vibration frequencies due to the coupling equations of a simply-supported microbeam resting on the three-parameter viscoelastic foundation. The fundamental frequencies are evaluated in terms of length-to-thickness ratio, width-to-thickness ratio and three foundation parameters. Sample natural frequencies are tabulated and plotted for sensing the effect of all used parameters and to investigate the visco-Pasternak's parameters for future comparisons.