• Title/Summary/Keyword: q-series

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An Over Current Protection Scheme for Hybrid Active Power filter

  • Lee Woo-Cheol;Chae Beom-Seok;Hyun Dong-Seok;Lee Taeck-Kie
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.571-575
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    • 2001
  • A protection scheme for hybrid active power filters, which is combined shunt passive filter and small rated series active filter, is presented and analyzed in this paper. The proposed series active power filter operated as a high impedance 'k($\Omega$)' to the fundamental component when over current occurs in the power distribution system, and three control strategies are proposed in this paper. The first is the method by detecting the fundamental source current through the p-q theory, the second is the method by detecting the fundamental component of load current in Synchronous Reference Frame (SRF) and the third is the method by detecting the input voltage. When the over current occurs in the power distribution system, the proposed scheme protects the series active power filter without additional protection circuits. The validity of proposed protection scheme is investigated through experimental result for the prototype hybrid active power filter system.

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CERTAIN UNIFIED INTEGRALS INVOLVING A PRODUCT OF BESSEL FUNCTIONS OF THE FIRST KIND

  • Choi, Junesang;Agarwal, Praveen
    • Honam Mathematical Journal
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    • v.35 no.4
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    • pp.667-677
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    • 2013
  • A remarkably large number of integrals involving a product of certain combinations of Bessel functions of several kinds as well as Bessel functions, themselves, have been investigated by many authors. Motivated the works of both Garg and Mittal and Ali, very recently, Choi and Agarwal gave two interesting unified integrals involving the Bessel function of the first kind $J_{\nu}(z)$. In the present sequel to the aforementioned investigations and some of the earlier works listed in the reference, we present two generalized integral formulas involving a product of Bessel functions of the first kind, which are expressed in terms of the generalized Lauricella series due to Srivastava and Daoust. Some interesting special cases and (potential) usefulness of our main results are also considered and remarked, respectively.

GENERALIZATIONS OF TWO SUMMATION FORMULAS FOR THE GENERALIZED HYPERGEOMETRIC FUNCTION OF HIGHER ORDER DUE TO EXTON

  • Choi, June-Sang;Rathie, Arjun Kumar
    • Communications of the Korean Mathematical Society
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    • v.25 no.3
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    • pp.385-389
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    • 2010
  • In 1997, Exton, by mainly employing a widely-used process of resolving hypergeometric series into odd and even parts, obtained some new and interesting summation formulas with arguments 1 and -1. We aim at showing how easily many summation formulas can be obtained by simply combining some known summation formulas. Indeed, we present 22 results in the form of two generalized summation formulas for the generalized hypergeometric series $_4F_3$, including two Exton's summation formulas for $_4F_3$ as special cases.

A Note on Gaussian Series Rings

  • Kim, Eun Sup;Lee, Seung Min;Lim, Jung Wook
    • Kyungpook Mathematical Journal
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    • v.57 no.3
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    • pp.419-431
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    • 2017
  • In this paper, we define a new kind of formal power series rings by using Gaussian binomial coefficients and investigate some properties. More precisely, we call such a ring a Gaussian series ring and study McCoy's theorem, Hermite properties and Noetherian properties.

FRACTIONAL INTEGRATION AND DIFFERENTIATION OF THE (p, q)-EXTENDED BESSEL FUNCTION

  • Choi, Junesang;Parmar, Rakesh K.
    • Bulletin of the Korean Mathematical Society
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    • v.55 no.2
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    • pp.599-610
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    • 2018
  • We aim to present some formulas for Saigo hypergeometric fractional integral and differential operators involving (p, q)-extended Bessel function $J_{{\nu},p,q}(z)$, which are expressed in terms of Hadamard product of the (p, q)-extended Gauss hypergeometric function and the Fox-Wright function $_p{\Psi}_q(z)$. A number of interesting special cases of our main results are also considered. Further, it is emphasized that the results presented here, which are seemingly complicated series, can reveal their involved properties via those of the two known functions in their respective Hadamard product.

Re-Transformation of Power Transformation for ARMA(p, q) Model - Simulation Study (ARMA(p, q) 모형에서 멱변환의 재변환에 관한 연구 - 모의실험을 중심으로)

  • Kang, Jun-Hoon;Shin, Key-Il
    • The Korean Journal of Applied Statistics
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    • v.28 no.3
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    • pp.511-527
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    • 2015
  • For time series analysis, power transformation (especially log-transformation) is widely used for variance stabilization or normalization for stationary ARMA(p, q) model. A simple and naive back transformed forecast is obtained by taking the inverse function of expectation. However, this back transformed forecast has a bias. Under the assumption that the log-transformed data is normally distributed. The unbiased back transformed forecast can be obtained by the expectation of log-normal distribution; consequently, the property of this back transformation was studied by Granger and Newbold (1976). We investigate the sensitivity of back transformed forecasts under several different underlying distributions using simulation studies.

On Strict Stationarity of Nonlinear Time Series Models without Irreducibility or Continuity Condition

  • Lee, Oe-Sook;Kim, Kyung-Hwa
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.1
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    • pp.211-218
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    • 2007
  • Nonlinear ARMA model $X_n\;=\;h(X_{n-1},{\cdots},X_{n-p},e_{n-1},{\cdots},e_{n-p})+e_n$ is considered and easy-to-check sufficient condition for strict stationarity of {$X_n$} without some irreducibility or continuity assumption is given. Threshold ARMA(p, q) and momentum threshold ARMA(p, q) models are examined as special cases.

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