• Title/Summary/Keyword: Beta-mixture

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Use of Beta-Polynomial Approximations for Variance Homogeneity Test and a Mixture of Beta Variates

  • Ha, Hyung-Tae;Kim, Chung-Ah
    • Communications for Statistical Applications and Methods
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    • v.16 no.2
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    • pp.389-396
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    • 2009
  • Approximations for the null distribution of a test statistic arising in multivariate analysis to test homogeneity of variances and a mixture of two beta distributions by making use of a product of beta baseline density function and a polynomial adjustment, so called beta-polynomial density approximant, are discussed. Explicit representations of density and distribution approximants of interest in each case can easily be obtained. Beta-polynomial density approximants produce good approximation over the entire range of the test statistic and also accommodate even the bimodal distribution using an artificial example of a mixture of two beta distributions.

Electrophoretic Behaviors of α-Lactalbumin and β-Lactoglobulin Mixtures Caused by Heat Treatment

  • Lee, You-Ra;Hong, Youn-Ho
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.7
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    • pp.1041-1045
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    • 2003
  • In order to study the reaction behaviors of bovine $\alpha$-lactalbumin ($\alpha$-La), $\beta$-lactoglobulin ($\beta$-Lg), and their mixtures during heat treatment, samples were analyzed using native-polyacrylamide gel electrophoresis (Native-PAGE), sodium dodecylsulfate (SDS)-PAGE, and two-dimensional (2-D)-PAGE. The electrophoresis demonstrated that the loss of native-$\alpha$-La increased as temperature increased, and that the loss of apo-$\alpha$-La was slightly higher than that of holo-$\alpha$-La. The tests also showed that during heat treatment, a mixture of $\alpha$-La and $\beta$-Lg was less stable than $\alpha$-La alone. As such, it was assumed that $\beta$-Lg induced holo-$\alpha$-La to be less stable than apo-$\alpha$-La during heat treatment. The reaction behavior of $\alpha$-La (holo-, apo-form) during heat treatment showed similar patterns in the 2-D-PAGE electropherogram, but the mixture of $\alpha$-La and $\beta$-Lg created new bands. In particular, the results showed a greater loss of native $\alpha$-La in the holo-$\alpha$-La and $\beta$-Lg mixture than in the apo-$\alpha$-La and $\beta$-Lg mixture. Thus, it can be concluded that the holo-$\alpha$-La and $\beta$-Lg mixture was more intensively affected by heat treatment than other samples, and that free sulphydryl groups took part in the heat-induced denaturation.

Antioxidant Action of Reaction Mixtures of Gums Hydrolysates and Urea Derivatives (중합도별 gum류 가수분해 올리고당과 urea관련화합물과의 반응혼합물이 항산화능에 미치는 영향)

  • Kim, Sang-Woo;Park, Gwi-Gun
    • Applied Biological Chemistry
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    • v.47 no.4
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    • pp.384-389
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    • 2004
  • The purified ${\beta}-mannanase$ hydrolyzed various gums to mannose, ${\beta}-1,4-mannobiose$, $Gal^3Man_4$, and D.P 7 of galactosyl mannooligosaccharide, and isolated from the enzymatic hydrolysate for 24 hrs reaction by activated carbon column chromatography and Sephadex G-25 column chromatography. For the elucidate of antioxidant action of ${\beta}-1,4-mannobiose$, $Gal^3Man_4$ and DP 7 of galactosyl mannooligosaccharide and urea derivatives, coloration, reducing power, antioxidant activity and DPPH test were accomplished. The coloration was high at reaction mixture of ${\beta}-1,4-mannobiose$, $Gal^3Man_4$ D.P 7 and urea. TLC of reaction mixture of ${\beta}-1,4-mannobiose$, $Gal^3Man_4$ D.P 7 and ureas showed new reaction products, respectively. but except reaction mixture of ${\beta}-1,4-mannobiose$ and urea. The reducing power was high at reaction mixture of ${\beta}-1,4-mannobiose$, $Gal^3Man_4$ D.P 7 and phenylthiourea. The reaction mixture of ${\beta}-1,4-mannobiose$, $Gal^3Man_4$ D.P 7 and thiourea showed similar radical scavenging activities on DPPH to activity of AsA. The reaction mixture of ${\beta}-1,4-mannobiose$, $Gal^3Man_4$ D.P 7 and thiourea, phenythiolurea shown strong antioxidative activites on the oxidation of linoneic acid.

Syntheses of SiC and $SiC-Si_3N_4$ Powder from Jecheon Quartz (제천규석으로부터 SiC 및 $SiC-Si_3N_4$계 분말 합성)

  • 이홍림;배철훈;문준화
    • Journal of the Korean Ceramic Society
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    • v.23 no.1
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    • pp.67-73
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    • 1986
  • SiC and $SiC-Si_3N_4$ powder were synthesized via the carbiding and carbiding-nitriding reaction of Jecheon quartz respectively using graphite as a reducing agent. $\beta$-SiC+($\alpha$+$\beta$)-$Si_3N_4$ composite was obtained by the carbiding-nitriding reaction of Jecheon quartz-graphite mixture at 1, 35$0^{\circ}C$ in $H_2$ atmosphere. $\beta$-SiC+($\alpha$+$\beta$)-$Si_3N_4$ composite was obtained by the carbidint-nitriding reaction of Jecheon quartz-graphite mixture at 1, 35$0^{\circ}C$ in $N_2-H_2$ atmosphere. The ratio of $\beta$-SiC+($\alpha$+$\beta$)-$Si_3N_4$ content in a produced composite could be controlled by adjusting the reaction time and gaseous mixture.

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Bayesian Inferences for Software Reliability Models Based on Beta-Mixture Mean Value Functions

  • Nam, Seung-Min;Kim, Ki-Woong;Cho, Sin-Sup;Yeo, In-Kwon
    • The Korean Journal of Applied Statistics
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    • v.21 no.5
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    • pp.835-843
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    • 2008
  • In this paper, we investigate a Bayesian inference for software reliability models based on mean value functions which take the form of the mixture of beta distribution functions. The posterior simulation via the Markov chain Monte Carlo approach is used to produce estimates of posterior properties. Its applicability is illustrated with two real data sets. We compute the predictive distribution and the marginal likelihood of various models to compare the performance of them. The model comparison results show that the model based on the beta-mixture performs better than other models.

Synthesis of Hβ (core)/SAPO-11 (shell) Composite Molecular Sieve and its Catalytic Performances in the Methylation of Naphthalene with Methanol

  • Wang, Xiaoxiao;Guo, Shaoqing;Zhao, Liangfu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3829-3834
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    • 2013
  • $H{\beta}$ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of $H{\beta}$ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of $H{\beta}$ and SAPO-11. The physicochemical properties of $H{\beta}$, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that $H{\beta}$/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the $H{\beta}$ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of $H{\beta}$ and SAPO-11. The composite had fewer acid sites than $H{\beta}$ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

Antiinflammatory effect of ursodeoxycholic acid and mixture of natural extracts combined with ursodeoxycholic acid (UDCA를 함유한 생약추출물혼합제제의 항염효과에 관한 연구)

  • Rhyu, In-Cheol;Kim, Sang-Nyun;Chung, Chong-Pyoung
    • Journal of Periodontal and Implant Science
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    • v.26 no.4
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    • pp.1013-1021
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    • 1996
  • There are many important factors in periodontal inflammation. $IL-1{\beta}$, $PGE_2$ and collagenase are predorminantly key factors. These inflammatory mediators induce gingival tissue and alveolar bone destruction. For the prevention and treatment of periodontal disease, it is necessary to inhibit $IL-1{\beta}$, $PGE_2$ production and collagenase activity. Ursodeoxycholic acid(UDCA) has immunomodulatory properties, and there is evidence that some natural extracts show antiinflammatory activity to some degree. The purpose of this study was to assess the inhibitory effect of UDCA and its mixture with natural extracts on $IL-1{\beta}$, $PGE_2$ production and collagenase activity. Accordingly we assessed the effect of UDCA and its mixture combined with some natural extracts on inhibition of $IL-1{\beta}$, $PGE_2$ production and collagenase activity. For the $IL-l{\beta}$ inhibition study, cultured cells were exposed to $25{\mu}g/ml$ LPS. $IL-1{\beta}$ activity was measured by $IL-1{\beta}$ enzyme immunoassay system. Human gingival fibroblasts were prepared and cells (l05/well) were seeded into culture plates. $rhIL-1{\beta}$ was added to induce $PGE_2$. The amount of $PGE_2$ in sample media was measured using enzyme immunoassay system. Crude collagenase was prepared from Porphyromonas gingivalis and collagenolytic activity was determined using a Collageno kit CLN-100. The test inhibitor was added to the assay mixture consisting of 0.1ml of 50mM Tris buffer(pH 7.5) and 0.2ml of substrate solution. UDCA and UDCA combined with natural extracts generally inhibited $IL-1{\beta}$ production. groups above 0.01% UDCA strongly inhibited $IL-l{\beta}$ synthesis. Both groups inhibited $IL-1{\beta}-induced$ synthesis of $PGE_2$. In low concentration, the degree of inhibition was as same as prednisolone. In high concentration, each group was superior to prednisolone. UDCA group and UDCA mixture group exerted a moderate inhibition of collagenolytic enzyme. The present study suggested that UDCA and its mixture with natural extracts could be further investigated as antiinflammatory drug for periodontal disease.

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THE UNIFORM MIXTURE OF GENERALIZED ARC-SINE DISTRIBUTIONS

  • JONES M.C.
    • Journal of the Korean Statistical Society
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    • v.34 no.1
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    • pp.35-38
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    • 2005
  • A single, tractable, special case of the problem of continuous mixtures of beta distributions over their parameters is considered. This is the uniform mixture of generalized arc-sine distributions which, curiously, turns out to be linked by transformation to the Cauchy distribution.

Beta glucan: Heath benefits of optimal ingredients via the mixture ratio of rice bran and Sarcodon aspratus

  • Seo, Yu-Ri;Kim, Hye-Been;Cheong, Kyu-Min;Lim, Ki-Taek
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.101-101
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    • 2017
  • Beta-glucan is a polymerized polysaccharide on beta-1,3 chemical bonds. It has the main pharmacological action of various anticancer mushrooms and is colorless and odorless. In addition, it enhances phagocytosis of macrophages against mycobacterium tuberculosism and increases resistance of host against food poisoning bacteria. Owing to these advantages, beta-glucan was used in various health supplement foods such as immune boosters, hypotensive agent and hypoglycemic agent. Our study was aimed to investigate the effective components of beta-glucan, which was optimized via the contents of Sarcodon aspratus and rice bran. First, the mixture ratio condition of Sarcodon aspratus and rice bran were respectively 10:0, 7:3, 5:5, 3:7, and 0:10. The raw materials were fabricated using hot water extraction method. Distilled water of 100 mL was added to the raw material and extracted. After the extraction processed, the content of effective components was analyzed. The absorbance of beta-glucan was measured using a beta-glucan kit (Megazyme, (1-3) (1-4) BETA-D-GLUCAN ASSAY KIT). The absorbance analysis was repeated three times for accurate analysis. After the extracts were lyophilized, the yields of extracted raw materials according to the mixture ratio conditions of Sarcodon aspratus and rice bran (10:0, 7:3, 5:5, 3:7, and 0:10) were respectively 33.1%, 34.5%, 35.3%, 30.7%, and 24.3%. The absorbance was 1.52, 1.47, 1.50, 1.79, and 1.56, respectively. As a result, the optimum ratio of beta-glucan is 3:7 at Sarcodon aspratus and rice bran. This study suggested that the optimal amount of beta-glucan could be used as a health supplement foods and food additive such as immune boosters, hypotensive agent and hypoglycemic agent. However, the new condition (temperature, time) of hot water extraction to maximize the content of beta-glucan could be considered, could be necessary to compare with the existing extracts.

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Synthesis of ${\beta}-FeSi_2$ Powder by Mechanical Alloying Process (기계적 합금화법에 의한 ${\beta}-FeSi_2$ 분말 함성)

  • 이충효;조재문;김환태;권영순
    • Journal of Powder Materials
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    • v.8 no.2
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    • pp.104-109
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    • 2001
  • The semiconducting ${\beta}-FeSi_2$ compound has been recognized as a thermoelectric material with excel-lent oxidation resistance and stable characteristics at elevated temperature. In the present work, we applied mechanical alloying(MA) technique to produce ${\beta}-FeSi_2$ compound using a mixture of elemental iron and silicon powders. The mechanical alloying was carried out using a Fritsch P-5 planetary mill under Ar gas atmosphere. The MA powders were characterized by the X-ray diffraction with Cu-K $\alpha$ radiation, thermal analysis and scanning electron microscopy. The single ${\beta}-FeSi_2$ phase has been obtained by mechanical alloying of $Fe_{33}Si_{67}$ mixture powders for 120 hrs or for 70 hrs coupled with the subsequent heat treatment up to $700^{\circ}C$. The grain size of ${\beta}-FeSi_2$ powders analyzed by Hall plot method was 44nm.

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