• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1181-1187
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• 2006

HS-1580 series (HS-1580, HS-1581, HS-1582) can produce anti-imflammatory effects were synthesized from the marine algae extraction in 2,3,6-tribromo-4,5-dihydroxy benzyl methyl ether (TDB). Raw 264.7 cells were pre-treated with $1{\mu}g/{\mu}l$ lipopolysaccharide (LPS) and later treated with HS-1580 series. These cells of inflammatory mediators were tested as well. Nitric oxide (NO) is related to autoimmune disease and is produced by inducible NOS (iNOS). When treated with HS-1580 series, the product of NO will reduce in a dose-dependent manner. HS-1580 series significantly inhibit the iNOS protein expression. Cyclooxygenase (COX) involves with the various physiologic events and catalyzes in prostaglandin. HS-1580 series also inhibit the COX-2 protein expression as well as pro-inflammatory cytokines production such as tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})\;and\;interluekin-1{\alpha]\;(IL-1{\beta})$. These upcoming results suggest that HS-1580 series have anti-inflammatory efforts in Raw 264.7 cells by inhibiting such as iNOS, COX-2, $TNF-{\alpha}\;and\;IL-1{\beta}$ as inflammatory mediators.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.203-208
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• 2006

This study compared the roundwood demand prediction accuracy of econometric and time-series models using Korean data. The roundwood was divided into softwood and hardwood by species. The econometric model of roundwood demand was specified with four explanatory variables; own price, substitute price, gross domestic product, dummy. The time-series model was specified with lagged endogenous variable. The dummy variable reflected the abrupt decrease in roundwood demand in the late 1990's in the case of softwood roundwood, and the boom of plywood export in the late 1970's in the case of hardwood roundwood. On the other hand, the prediction accuracy was estimated on the basis of Residual Mean Square Errors(RMSE). The results showed that the softwood roundwood demand prediction can be performed more accurately by econometric model than by time-series model. However, the hardwood roundwood demand prediction accuracy was similar in the case of using econometric and time-series model.

• 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.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.2
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• pp.73-80
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• 2011

The present study deals with the propeller design for the standard new propeller series so called KF Series for 52ton class fishing vessel. The MAU or B series have been usually used for the fishing vessel's propeller, which are to be improved in consideration of the efficiency as well as the cavitation point of view. The high technology of propeller design has been applied to the design of 52ton class fishing vessel's propeller in the present study. The new designed series propellers will be validated by the experimental results whose data will be also used for the new series chart.

• Journal of the Chungcheong Mathematical Society
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• v.31 no.3
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• pp.281-285
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• 2018

Let $S_k(N)$ be the space of cusp forms of weight k for ${\Gamma}_0(N)$. We show that $S_k(N)$ is the direct sum of subspaces $S_k^+(N)$ and $S_k^-(N)$. Where $S_k^+(N)$ is the vector space of cusp forms of weight k for the group ${\Gamma}_0^+(N)$ generated by ${\Gamma}_0(N)$ and $W_N$ and $S_k^-(N)$ is the subspace consisting of elements f in $S_k(N)$ satisfying $f{\mid}_kW_N=-f$. We find generators spanning the space $S_k^-(N)$ from $Poincar{\acute{e}}$ series and give all linear relations among such generators.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.1101-1121
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• 2008

One proposes an approach to fractional Fourier's transform, or Fourier's transform of fractional order, which applies to functions which are fractional differentiable but are not necessarily differentiable, in such a manner that they cannot be analyzed by using the so-called Caputo-Djrbashian fractional derivative. Firstly, as a preliminary, one defines fractional sine and cosine functions, therefore one obtains Fourier's series of fractional order. Then one defines the fractional Fourier's transform. The main properties of this fractal transformation are exhibited, the Parseval equation is obtained as well as the fractional Fourier inversion theorem. The prospect of application for this new tool is the spectral density analysis of signals, in signal processing, and the analysis of some partial differential equations of fractional order.

• Bulletin of the Korean Mathematical Society
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• v.35 no.2
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• pp.339-344
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• 1998

The aim of this paper is to establish generalizations of the well known Preece's identity and other identities involving product of generalized hypergeometric series by using new and very short method.

• Industrial Engineering and Management Systems
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• v.14 no.3
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• pp.312-317
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• 2015

The dynamic system approach in time series has been used in many real problems. Based on Taken's embedding theorem, we can build the predictive function where input is the time delay coordinates vector which consists of the lagged values of the observed series and output is the future values of the observed series. Although the time delay coordinates vector from multivariate time series brings more information than the one from univariate time series, it can exhibit statistical redundancy which disturbs the performance of the prediction function. We apply dimension reduction techniques to solve this problem and analyze the effect of this approach for prediction. Our experiment uses delayed Lorenz series; least squares support vector regression approximates the predictive function. The result shows that linearly preserving projection improves the prediction performance.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.583-592
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• 2015

Zero-inflation has recently attracted much attention in integer-valued time series. This article deals with conditional variance (volatility) modeling for the zero-inflated count time series. We incorporate zero-inflation property into integer-valued GARCH (INGARCH) via conditional Poisson and negative binomial marginals. The Cholera frequency time series is analyzed as a data application. Estimation is carried out using EM-algorithm as suggested by Zhu (2012).

• The Korean Journal of Applied Statistics
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• v.27 no.7
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• pp.1219-1228
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• 2014

Constant conditional correlation (CCC) is frequently employed for parsimony in the field of multivariate GARCH time series. An extended-CCC (ECCC) model is further developed in order to allow interactions between multivariate volatilities. The paper introduces both CCC model and ECCC model to the domestic financial time series. The CCC and ECCC models are fitted and then compared with each other through various multivatiate time series.