• 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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    • 제16권2호
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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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    • 제16권7호
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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.

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

  • 김상우;박귀근
    • Applied Biological Chemistry
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    • 제47권4호
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    • pp.384-389
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    • 2004
  • $100^{\circ}C$에서 반응시켜 2, 4, 6, 8시간의 갈변도 변화는 ${\beta}-1,4-mannobiose$와 urea의 반응혼합물이 시간의 경과함에 따라 강한 착색도의 증가를 나타냈으나 phenylthiourea, thiourea의 반응액은 착색속도가 늦었다. 같은 조건하에서 $Gal^3Man_4$와 urea 관련화합물의 각 반응혼합물의 갈변도를 나타낸 것으로 urea가 강한 착색도의 중가를 보였고 phenylthiourea, thiourea의 반응액은 비교적 높은 착색도를 보였다. DP 7의 galactosyl mannooligosaccharide와의 각 반응혼합물의 갈변도는 urea의 반응액이 강한 착색을 보였으며 phenylthiourea, thiourea의 반응액의 순으로 착색를 나타내었다. 반응혼합물의 TLC 결과에서 ${\beta}-1,4-mannobiose$와 urea의 반응혼합물 이외에 phenylthiourea, thiourea의 반응액은 새로운 화합물이 생성되었고, $Gal^3Man_4$와 D.P 7 galactosyl manooligosaccharide와의 반응혼합물에서는 모든 반응액에서 새로운 화합물이 출현되었다. 반응혼합물의 환원력은 urea관련화합물 중에서 특히 phenylthiourea, thiourea가 ${\beta}-1,4-mannobiose,\;Gal^3Man_4$, DP 7의 galactosyl manooligosaccharide와의 반응혼합물에서 강한 환원력이 나타났다. Linoleic acid에 대한 반응혼합물의 항산화력 측정에서 ${\beta}-1,4-mannobiose$와 thiourea의 반응혼합물의 항산화력이 Ascorbic acid(AsA)수준의 항산화력을 나타내었고, $Gal^3Man_4$와 thiourea, phenylthiourea의 반응혼합물은 AsA와 유사한 항산화능을 나타내었다. DP 7의 galactosyl manooligosaccharide와 thiourea, phenylthiourea의 반응혼합물의 항산화력은 AsA에 미치지는 못하였다. ${\beta}-1,4-Mannobiose$와 thiourea, phenylthiourea의 반응혼합물이 강한 전자공여능을 나타내고 있고, $Gal^3Man_4$와 phenylthiourea의 반응혼합물 및 D.P 7의 galactosyl manooligosaccharide와 phenylthiourea와의 반응혼합물이 전자공여능을 나타내고 있다.

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

  • 이홍림;배철훈;문준화
    • 한국세라믹학회지
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    • 제23권1호
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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
    • 응용통계연구
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    • 제21권5호
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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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    • 제34권12호
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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.

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

  • 류인철;김상년;정종평
    • Journal of Periodontal and Implant Science
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    • 제26권4호
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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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    • 제34권1호
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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
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2017년도 춘계공동학술대회
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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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기계적 합금화법에 의한 ${\beta}-FeSi_2$ 분말 함성 (Synthesis of ${\beta}-FeSi_2$ Powder by Mechanical Alloying Process)

  • 이충효;조재문;김환태;권영순
    • 한국분말재료학회지
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    • 제8권2호
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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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