• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1433-1437
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• 2007

This paper describes the detection algorithm which can distinguish series arcing signal from voltage harmonics or noises produced by the operation of non-linear loads. A high pass filter with the cutoff frequency of 3 kHz is designed and it can attenuate power frequency signal to 80 dB. Series arcing phenomena is simulated to an incandescent lamp controlled by a dimmer. From the experimental results, it is confirmed that the amplitude of the filter output voltage varies at random during series arcing but the signal generated by non-linear loads appears on a regular basis. We proposed a series arcing detection algorithm using the chaotic nature of voltage signal.

• Communications for Statistical Applications and Methods
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• v.18 no.1
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• pp.13-21
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• 2011

This paper studies the analysis of multivariate nonstationary time series with seasonality. Three types of multivariate time series models are considered: seasonal cointegration model, nonseasonal cointegration model with seasonal dummies, and vector autoregressive model in seasonal differences that are compared for forecasting performances using Korean macro-economic time series data. The cointegration models produce smaller forecast errors in short horizons; however, when longer forecasting periods are considered the vector autoregressive model appears preferable.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.6
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• pp.701-707
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• 2007

The information on the incoming load to wastewater treatment plants is not often available to apply to evaluate effects of control actions on the field plant. In this study, a time series model was developed to forecast influent flow rate, BOD, COD, SS, TN and TP concentrations using field operating data. The developed time series model could predict 1 day ahead forecasting results accurately. The coefficient of determination between measured data and 1 day ahead forecasting results has a range from 0.8898 to 0.9971. So, the corelation is relatively high. We made forecasting program based on the time series model developed and hope that the program will assist the operators in the stable operation in wastewater treatment plants.

• 한국데이터정보과학회:학술대회논문집
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• 2004.04a
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• pp.91-101
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• 2004

The turbulent flow is of fundamental interest because the conservation equations for thermodynamics, mass and momentum are linked together. This turbulent flow consists of some coherent time- and space-organized vortical structures. Research has already shown that some dynamic systems and experimental models still cannot provide a good nonlinear analysis of turbulent time series. In the real turbulent flow, very complicated nonlinear behaviors, which are affected by many vague factors are present. In this paper, a kernel-based machine for fuzzy nonlinear regression analysis is proposed to predict the nonlinear time series of turbulent flows. In order to show the practicality and usefulness of this model, we present an example of predicting the near-wall turbulence time series as a verifiable model and compare with fuzzy piecewise regression. The results of practical applications show that the proposed method is appropriate and appears to be useful in nonlinear analysis and in fuzzy environments to predict the turbulence time series.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.904-905
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• 2008

In this paper, a novel 60kV, 300A, 3kHz pulsed power supply based on IGBT stacks is proposed. Proposed scheme consists of series connected 9 power stages to generate maximum 60kV output pulse and 15kW series resonant power inverter to charge DC capacitor voltage. Each power stages are configured as 8 series connected power cells and each power cell generates up to 830VDC, 300A pulses. Finally pulse output voltage is applied using total 72 series connected IGBTs. The synchronization of gating signal is important of series operation of IGBTs. For gating signal synchronization, full bridge inverter and pulse transformer generates on-off signals of IGBT gating and specially designed gate power circuit was used.

• Communications of the Korean Mathematical Society
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• v.19 no.3
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• pp.569-576
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• 2004

In 1965, Bhatt and Pandey obtained the Watson's theorem for double series by using Dioxon's theorem on the sum of a $_3F_2$. The aim of this paper is to derive twenty three results for double series closely related to the Watson's theorem for double series obtained by Bhatt and Pandey. The results are derived with the help of twenty three summation formulas closely related to the Dison's theorem on the sum of a $_3F_2$ obtained in earlier work by Lavoie, Grondin, Rathie and Arora.

• Communications of the Korean Mathematical Society
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• v.32 no.4
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• pp.865-874
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• 2017

In the theory of hypergeometric and generalized hypergeometric series, classical summation theorems have been found interesting applications in obtaining various series identities for ${\Pi}$, ${\Pi}^2$ and ${\frac{1}{\Pi}}$. The aim of this research paper is to provide twelve general formulas for ${\frac{1}{\Pi}}$. On specializing the parameters, a large number of very interesting series identities for ${\frac{1}{\Pi}}$ not previously appeared in the literature have been obtained. Also, several other results for multiples of ${\Pi}$, ${\Pi}^2$, ${\frac{1}{{\Pi}^2}}$, ${\frac{1}{{\Pi}^3}}$ and ${\frac{1}{\sqrt{\Pi}}}$ have been obtained. The results are established with the help of the extensions of classical Gauss's summation theorem available in the literature.

• The International Journal of Costume Culture
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• v.13 no.1
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• pp.5-8
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• 2010

The goal of this study is to analyze the influence of the costume culture of South Korean movies and television series on the development of fashion industry. South Korean movies and television series make full use of the influence of costume culture to advocate Korea's national spirit and character as well as the confidence and vigor of the young generation. They contribute to establishing South Korea as a country with a graceful, modern appearance and great cultural heritage. The presentation and promotion of its costume culture in movie and television series stimulates its cultural competence and advances its cultural creative industry. The spread of Korean costume culture has become the pioneer and foreshadowing of clothing industries and greatly underpins its advancement overseas. In concert, the development of clothing industry helps the spread of Korean costume culture.

• Journal of Information Display
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• v.10 no.4
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• pp.188-194
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• 2009

Conventional stereoscopic (3D) displays using binocular parallax generate unnatural conflicts between convergence and accommodation. These conflicts can affect the observer's ability to fuse binocular images and may cause visual fatigue. In this study, time series changes in visual fatigue and depth sensation when viewing stereoscopic images with changing parallax were examined. In particular, the physiological changes, including the subjective symptoms of visual fatigue, when viewing five parallax conditions, were examined. Then a comparative analysis of the 2D and 3D conditions was performed based on the visual function. To obtain data regarding the visual function, the time series changes in the spontaneous-blinking rate before and during the viewing of 3D images were measured. The time series change results suggest that 2D and 3D images cause significantly different types of visual fatigue over the range of binocular disparity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.3
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• pp.278-284
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• 2005

In this paper, phase controlled series resonant converter (PCSRC) system for power supply of communication station is suggested. PCSRC system is robust to load variations because it is POSR (parallel output series resonant) type. And it provides stable output voltage by changing phase of MOSFET switches to input voltage variations. Firstly, operation analysis about suggested series resonant converter system was carried. Then simulations using PSIM and experiments to actual system were carried to prove characteristics of suggested system.