• Title/Summary/Keyword: Distribution Journal

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D-UPFC Application as the Series Power Device in the Massive Roof-top PVs and Domestic Loads

  • Lee, Kyungsoo
    • Current Photovoltaic Research
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    • v.4 no.4
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    • pp.131-139
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    • 2016
  • This paper shows the series power device in the massive roof-top PVs and domestic loads. D-UPFC as the series power device controls the distribution voltage during voltage rise (or fall) condition. D-UPFC consists of the bi-directional ac-ac converter and the transformer. In order to verify the D-UPFC voltage control, the distribution model is used in the case study. D-UPFC enables the voltage control in the distribution voltage range. Dynamic voltage control from voltage rise and voltage fall conditions is performed. Scaled-down experimental test of the D-UPFC is verified the voltage control and it is well performed without high voltage spikes in the inductive load.

Molecular Species Composition of Phosphatidylcholine Isolated from Chum Salmon Meat Oil

  • Lee, Seung-Joo;Ha, Wang-Hyun;Choi, Hye-Jin;Cho, Soon-Yeong
    • Fisheries and Aquatic Sciences
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    • v.13 no.3
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    • pp.206-209
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    • 2010
  • Chum salmon (Oncorhynchus keta) meat oil contained high amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) compared to oils extracted from other tissues of the fish. EPA and DHA occupied more than 25% of the total fatty acids in chum salmon meat oil. The main lipid classes in the meat oil were triacylglycerides and phospholipids. The major fatty acids of the molecular species composition of phosphatidylcholine isolated from the meat oil were DHA and EPA. DHA and EPA were the major molecular species in the phosphatidylcholine of chum salmon meat oil, representing 44% and 17%, respectively.

Anti-arteriosclerotic and Anti-hyperlipidemic Effects of Sea Mustard (Undaria pinnatifida) in Sprague-Dawley rats

  • Lee, Seung-Joo;Ha, Wang-Hyun;Choi, Hye-Jin;Cho, Soon-Yeong;Choi, Jong-Won
    • Fisheries and Aquatic Sciences
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    • v.13 no.3
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    • pp.197-205
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    • 2010
  • This study investigated the inhibitory effects of sea mustard on high-fat diet-induced obesity and hyperlipidemia in Sprague-Dawley rats. Sea mustard (Undaria pinnatifida) powder, sea mustard ethanol extract, and sea mustard ethanol-extracted residue were tested. The ethanol extracted residue had the most beneficial anti-hyperlipidemic activity. Alginate in the sea mustard was considered to be the key component. The ethanol-extracted residue of sea mustard also had antioxidant activity, which may be effective in preventing hyperlipidemia by increasing the enzymatic activity of superoxide dismutase, which can remove active oxygen from the bloodstream.

Preparation and Characterization of Microcapsule for non-aqueous dyeing (비수계 염색용 마이크로캡슐의 제조 및 성질)

  • 최창남;박원규;변수진;이기영
    • Textile Coloration and Finishing
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    • v.15 no.5
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    • pp.327-332
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    • 2003
  • In this study, the polyurethane microcapsules for non-aqueous dyeing containing iron oxide and disperse dyes were prepared by in-situ polymerization method using hexamethylene diisocyanate(HDI) with ethylene glycol(EG). And the size, shape, and particle size distribution of microcapsules prepared were investigated. The size and shape of microcapsule were observed by optical microscope and scanning elecron microscope. The particle size distribution was analyzed by particle size analyzer. The microcapsule size and its distribution were largely effected by the existance of surface active agent in the system. When a surfactant did not exist in the system, the size distribution of microcapsules prepared was much uneven. By adding a surfactant, this phenomenon was disappeared. And the size of microcapsule was also effeced by the hydrophobicity of core material(disperse dye). It was considered due to the difference of dispersity of core materials. And the size of microcapsule prepared was inversely proportional to the stirring speed.

On the Estimation of the Empirical Distribution Function for Negatively Associated Processes

  • Kim, Tae-Sung;Lee, Seung-Woo;Ko, Mi-Hwa
    • Communications for Statistical Applications and Methods
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    • v.8 no.1
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    • pp.229-235
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    • 2001
  • Let {X$\_$n/, n$\geq$1] be a stationary sequence of negatively associated random variables with distribution function F(x)=P(X$_1$$\leq$x). The empirical distribution function F$\_$n/(x) based on X$_1$, X$_2$,....., X$\_$n/ is proposed as an estimator for F$\_$n/(x). Strong consistency and asymptotic normality of F$\_$n/(x) are studied. We also apply these ideas to estimation of the survival function.

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Distribution Analysis of Local Critical Temperature and Current Density in YBCO Coated Conductors using Low-temperature Scanning Laser Microscopy (저온 주사 레이저 현미경(LTSLM)을 이용한 YBCO 초전도 선재의 국소적 임계 온도 및 전류 밀도 분포 분석)

  • Park, S.K.;Cho, B.R.;Ri, H.C.
    • Progress in Superconductivity
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    • v.12 no.1
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    • pp.17-22
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    • 2010
  • Distribution of local critical temperature and current density in $YBa_2Cu_3O_{7-\delta}$ (YBCO) coated conductors was analyzed using a Low-temperature Scanning Laser Microscopy (LTSLM). We prepared YBCO coated conductors of various bridge types to study the spatial distribution of critical temperature and current density in single and multi bridges. An LTSLM system was modified for a detailed two-dimensional scan without shifting of the sample. We observed a spatial distribution of the critical temperature from the bolometric response, which arises from a focused laser beam at the sample near the superconducting transition. Also we studied the relation between the critical temperature and the current density.

Regime-dependent Characteristics of KOSPI Return

  • Kim, Woohwan;Bang, Seungbeom
    • Communications for Statistical Applications and Methods
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    • v.21 no.6
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    • pp.501-512
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    • 2014
  • Stylized facts on asset return are fat-tail, asymmetry, volatility clustering and structure changes. This paper simultaneously captures these characteristics by introducing a multi-regime models: Finite mixture distribution and regime switching GARCH model. Analyzing the daily KOSPI return from $4^{th}$ January 2000 to $30^{th}$ June 2014, we find that a two-component mixture of t distribution is a good candidate to describe the shape of the KOSPI return from unconditional and conditional perspectives. Empirical results suggest that the equality assumption on the shape parameter of t distribution yields better discrimination of heterogeneity component in return data. We report the strong regime-dependent characteristics in volatility dynamics with high persistence and asymmetry by employing a regime switching GJR-GARCH model with t innovation model. Compared to two sub-samples, Pre-Crisis (January 2003 ~ December 2007) and Post-Crisis (January 2010 ~ June 2014), we find that the degree of persistence in the Pre-Crisis is higher than in the Post-Crisis along with a strong asymmetry in the low-volatility (high-volatility) regime during the Pre-Crisis (Post-Crisis).

A study on the microstructure and micro-hardenss distribution in laser welded AZ31 magnesium alloy (AZ31 마그네슘합금 레이저 용접부의 미세조직 및 미소경도의 분포에 관한 연구)

  • Choi, Y.H.;Lee, M.Y.;Choi, S.H.
    • Laser Solutions
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    • v.15 no.3
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    • pp.11-15
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    • 2012
  • The laser weld of AZ31 magnesium alloy was characterized with OM, EBSD and micros vickers hardness tester in experiment. EBSD analysis and micro-hardness measurements were carried out at the three regions (Equiaxed Zone, Columnar Dendrite Zone, Base Metal) of the welded AZ31Mg alloy sheets. The magnesium alloy show the rectangular shape bead in laser weld. EBSD analysis revealed that the three regions show the heterogeneous distribution of grain size and microtexture. Micro-hardness measurement also revealed that the heterogeneous distribution of microstructure contributed to the heterogeneous micro-hardness distribution in the three regions.

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Robust inference with order constraint in microarray study

  • Kang, Joonsung
    • Communications for Statistical Applications and Methods
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    • v.25 no.5
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    • pp.559-568
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    • 2018
  • Gene classification can involve complex order-restricted inference. Examining gene expression pattern across groups with order-restriction makes standard statistical inference ineffective and thus, requires different methods. For this problem, Roy's union-intersection principle has some merit. The M-estimator adjusting for outlier arrays in a microarray study produces a robust test statistic with distribution-insensitive clustering of genes. The M-estimator in conjunction with a union-intersection principle provides a nonstandard robust procedure. By exact permutation distribution theory, a conditionally distribution-free test based on the proposed test statistic generates corresponding p-values in a small sample size setup. We apply a false discovery rate (FDR) as a multiple testing procedure to p-values in simulated data and real microarray data. FDR procedure for proposed test statistics controls the FDR at all levels of ${\alpha}$ and ${\pi}_0$ (the proportion of true null); however, the FDR procedure for test statistics based upon normal theory (ANOVA) fails to control FDR.

Research on the Energy Hole Problem Based on Non-uniform Node Distribution for Wireless Sensor Networks

  • Liu, Tang;Peng, Jian;Wang, Xiao-Fen;Yang, Jin;Guo, Bing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.9
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    • pp.2017-2036
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    • 2012
  • Based on the current solutions to the problem of energy hole, this paper proposed a nonuniform node distribution clustering algorithm, NNDC. Firstly, we divide the network into rings, and then have an analysis and calculation on nodes' energy consumption in each ring of the network when clustering algorithm is applied to collect data. We also put forward a scheme of nonuniform node distribution on the basis of the proportion of nodes' energy consumption in each ring, and change nodes' active/hibernating states under density control mechanism when network coverage is guaranteed. Simulation shows NNDC algorithm can satisfyingly balance nodes' energy consumption and effectively avoid the problem of energy hole.