• Title/Summary/Keyword: $Y_H$

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Effects of Anti-Helicobacter pylori IgY Powder to Protect Mice from Helicobacter pylori (Helicobacter pylori 감염생쥐에서 항-Helicobacter pylori 난황항체 분말의 효과)

  • Jung, Soon-Hee;Kim, Hyun-Jue;Lyoo, Young-Soo;Rho, Jeong-Hae;Lee, Nam-Hyung
    • Korean Journal of Food Science and Technology
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    • v.38 no.1
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    • pp.93-98
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    • 2006
  • Effects of anti-Helicobacter pylori IgY powder on H. pylori infection were evaluated 3 and 7 weeks after powder feeding by urease, PCR, and histological tests, and specific IgG assay of murine gastric tissue using mouse model. To produce anti-H. pylori IgY powder, laying hens were immunized with H. pylori prior to egg yolk harvest. C57BL/6 mice showing high response to H. pylori were infected with H. pylori and fed with the anti-H. pylori IgY powder. In urease and PCR tests, urease activity and gene count of anti-H. pylori IgY powder-fed group significantly decreased in comparison with control. Histological results indicated anti-H. pylori IgY powder effectively protected mice from H. pylori.

Studies on the Standardization of pH Measurement System (pH 측정 시스템의 표준화에 관한 연구)

  • Lee, Hwa Shim;Kim, Myung Soo;Kim, Jin Bok;Oh, Sang Hyup
    • Journal of the Korean Chemical Society
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    • v.42 no.4
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    • pp.432-442
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    • 1998
  • Since the definition of pH, $pH=-Ioga_H$ is based on a single ion activity, pH values can not be determined with measurement itself, but require an approximation method. They are derived from EMF measurement of a liquid junction free cell using hydrogen and Ag/AgCl electrodes. Primary standard materials with certified pH values can be obtained with this approximation method. Standard buffer solutions are used to calibrate pH meters. Thus the accuracy of the pH values of standard buffer solutions limits the reliability of measured pH values can be obtained with this approximation method. Standard buffer solution are used to calibrate pH meters. Thus the accuracy of the pH values of standard buffer solutions limits the reliability of measured pH values of sample solutions. To certify the pH values, we have established the system for the primary standard measurement and certified the pH of buffer solutions in the range of 1.6∼12.5 pH unit within uncertainty of ${\pm}0.005$ pH unit.

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$H_{2}$/$H_{\infty}$ control of active suspension system (능동 현가 시스템을 위한 $H_{2}$/$H_{\infty}$ 제어기 설계)

  • 정우영;김상우;원상철
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.888-891
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    • 1996
  • The objective of a mixed H$_{2}$/H$_{\infty}$ controller of active suspension system is to achieve not only the general performance improvement(H$_{2}$) but also the worst case disturbance rejection(H$_{\infty}$). In this paper, a mixed H$_{2}$/H$_{\infty}$ controller for an active suspension system, comparing the performance with that of an H$_{2}$ controller and of an H$_{\infty}$ controller.ler.EX> controller.

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Mixed $H_2/H_{\infty}$ Controller Realization with Entropy Integral

  • Lee, Sang-Hyuk;Kim, Ju-Sik
    • International Journal of Control, Automation, and Systems
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    • v.1 no.2
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    • pp.206-209
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    • 2003
  • An $H_2$/$H_{\infty}$ -controller realization is carried out by considering an entropy integral. Using J-spectral factorization, the parametrizations of all $H_{\infty}$ stabilizing controllers are derived. By the relation of a mixed $H_2$/$H_{\infty}$ control problem and a minimum entropy/$H_{\infty}$ control problem, the mixed $H_2$/$H_{\infty}$-controller state-space realization is presented.

A mixed $H_2/ H_\infty$ digital control of Inverted pendulum system (도립진자 시스템의 혼합$H_2/ H_\infty$ 디지털 제어)

  • 박종우;곽칠성
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.1111-1116
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    • 2000
  • The mixed $H_2/ H_\infty$ control method is one of positive approaches to design a controller having both the$H_2$-performance and the $H_\infty$-robust stability. In this paper, Firstly, The tracking Performance to be designed has been represented as $H_2$-norms for the plants with uncertainties. Secondly, $H_\infty$-norm have been set up in order to ensure the robust stabilities. The mixed digital controllers have been designed for an inverted system. The mixed $H_2/ H_\infty$digital controller for the inverted pendulum system was intended to stabilize the unstability of the plant together with the good tracking Performance.

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Molecular Phylogenetic Studies of Korean Hydrocotyle L. (한국산 피막이속(Hydrocotyle L.) 식물의 분자계통학적 연구)

  • Choi, Kyoung-Su;Park, Seon-Joo
    • Korean Journal of Plant Resources
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    • v.25 no.4
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    • pp.490-497
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    • 2012
  • Phylogenetic analyses were conducted to evaluate relationships of 5 taxa of Korean Hydrocotyle, H. spp. found in the Ulleung island including one outgroup (Centella asiatica). The molecular phylogenetic methods based on nuclear ribosomal DNA ITS region and cpDNA trnH-psbA region. Centella asiatica was used outgroup for analysis. As the result, genus Korean Hydrocotyle were grouped by 94% bootstrap value. Korean Hydrocotyle was grouped by four clades; Clade I-H. maritima, H. sibthorpides and H. yabei clade Clade II-H. nepalensis clade clade III-H. ramiflora clade clade IV-H. spp. clade. H. maritima, H. sibthorpides and H. yabei was not distinguished, seperately. H. spp. was distinctly distinguished other Korean Hydrocotyle.

Comparison of Pork Quality by Different Postmortem pH24 Values (돈육의 사후 24시간 pH 수준에 따른 육질 특성)

  • Park, B.Y.;Cho, S.H.;Yoo, Y.M.;Kim, J.H.;Chae, H.S.;Ahn, J.N.;Kim, Y.K.;Lee, J.M.;Yun, S.G.
    • Journal of Animal Science and Technology
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    • v.44 no.2
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    • pp.233-238
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    • 2002
  • Meat quality of the domestic pork loins(n=537) classified by 3 groups(5.31-5.50, 5.51-5.70 and $\geq$5.71) according to pH at 24hr post-mortem(pH24) was investigated. In proximate chemical compositions, protein was highest and fat was lowest in the pork loins of pH24 5.31-5.50 group. Water holding capacity increased as pH24 increased, whereas purge loss and cooking loss decreased as pH24 increased. Meat color values(CIE L*, a*, b*, Chroma, Hue and $\Delta$E) decreased as $pH_{24}$ increased. In texture traits, hardness and chewiness were lowest and fat hardness was highest in the pork loins of $pH_{24}{\geq}$5.71 group when compared to the other $pH_{24}$ groups. However, Warner-Bratzler Shear force, springiness and cohesiveness were not significantly different among the pH24 groups(P>0.05). In sensory properties, juiciness and tenderness were highest in $pH_{24}{\geq}$5.71 group. From the results of this study, pork quality was highly related to $pH_{24}$. Therefore, the factors affecting the post-mortem pH, such as stress before slaughter, slaughtering methods, and cooling condition slaughter must be properly controlled and improved to produce high quality pork.

Histone H3K27 Modifications and Gene Transcription (히스톤 H3K27 변형과 유전자 전사)

  • Kim, Ae-Ri
    • Journal of Life Science
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    • v.21 no.4
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    • pp.616-620
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    • 2011
  • Lysine residues of histone H3 and H4 are covalently modified in the chromatin of eukaryotic cells. Lysine 27 in histone H3 was acetylated (H3K27ac) or methylated at three levels; mono-, di-, and trimethylation (H3K27me1, H3K27me2, and H3K27me3). These modifications at H3K27 were related with gene transcription and/or chromatin structure in distinct patterns. Generally, H3K27ac and H3K27me1 were enriched in active chromatin, such as the locus control region or transcriptionally active genes, while transcriptionally inactive genes were highly marked by H3K27me2 and H3K27me3. These modifications appear to have been catalyzed by distinct histone-modifying enzymes. Recent studies suggest that the four kinds of modifications at H3K27 have inter-correlation in gene transcription or chromatin structure formation.

The LMI mixed ${H_2}/H_{\infty}$ control of inverted pendulum system using LFR (도립진자 시스템의 LFR에 의한 LMI 혼합 ${H_2}/H_{\infty}$ 제어)

  • 박종우;이상철;이상효
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.7A
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    • pp.967-977
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    • 2000
  • In this paper, we apply a mixed $H_2/H_{\infty}$ control to a generalized plant of inverted pendulum system represented by an LFR(Linear Fractional Representation). First, in order to obtain the generalized plant, the linear model of the inverted pendulum represented by an LFR(Linear fractional Representation) is derived. In LFR, we consider system uncertainties as three nonlinear components and a pendulum mass uncertainty. Augmenting the LFR model by adding weighting functions, we get a generalized plant. And then, we design a mixed $H_2/H_{\infty}$ controller for the generalized plant. In order to design the mixed $H_2/H_{\infty}$ controller, we use the LMI technique. To evaluate control performances and robust stability of the mixed $H_2/H_{\infty}$ controller designed, we compare it with the $H_{\infty}$ controller through the simulation and experiment. In the result, with the fewer feedback information, the mixed $H_2/H_{\infty}$ controller shows the better control performances and robust stability than the $H_{\infty}$ controller in the sense of pendulum angle.

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Taxonomic revision of the genus Herposiphonia (Rhodomelaceae, Rhodophyta) from Korea, with the description of three new species

  • Koh, Young Ho;Kim, Myung Sook
    • ALGAE
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    • v.33 no.1
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    • pp.69-84
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    • 2018
  • We examined the species diversity of Herposiphonia on Korean coasts, based on a combination of morphology and molecular analyses of the mitochondrial COI-5P DNA barcode marker and plastid rbcL gene. We report the presence of eight species including three novel species: H. donghaensis sp. nov., H. jejuinsula sp. nov., H. sparsa sp. nov., H. caespitosa, H. fissidentoides, H. insidiosa, H. parca, and H. subdisticha. Specimens were separated into eight clades in both the COI-5P and rbcL gene analyses, with 1.3-19.6 and 6.6-15% interspecific sequence divergence, respectively. These eight species are also distinguishable by several morphological characteristics such as: branching pattern (d/i pattern in H. donghaensis sp. nov. and H. sparsa sp. nov.; d/d/d/i pattern in others), shape of determinate branch (ligulate in H. fissidentoides; terete in others), number of vegetative trichoblasts (1-2 in H. insidiosa and H. sparsa sp. nov.; 3-4 in H. caespitosa; absent in others), and number of segments and pericentral cells in determinate branches. About three novel species revealed by our analyses, H. donghaensis sp. nov. is newly discovered, and H. jejuinsula sp. nov. and H. sparsa sp. nov. were previously reported in Korea as H. nuda and H. secunda, respectively. Our results show that DNA barcoding and rbcL analyses are useful for delimiting species boundaries and discovering cryptic species diversity in the genus Herposiphonia.