• Title/Summary/Keyword: gamma model

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Service Life Prediction for Building Materials and Components with Stochastic Deterioration (추계적 열화모형에 의한 건설자재의 사용수명 예측)

  • Kwon, Young-Il
    • Journal of Korean Society for Quality Management
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    • v.35 no.4
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    • pp.61-66
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    • 2007
  • The performance of a building material degrades as time goes by and the failure of the material is often defined as the point at which the performance of the material reaches a pre-specified degraded level. Based on a stochastic deterioration model, a performance based service life prediction method for building materials and components is developed. As a stochastic degradation model, a gamma process is considered and lifetime distribution and service life of a material are predicted using the degradation model. A numerical example is provided to illustrate the use of the proposed service life prediction method.

H$\gamma$LINE SPECTRUM OF INTERMEDIATE POLARS

  • Kim, Yong-Gi
    • Journal of Astronomy and Space Sciences
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    • v.15 no.1
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    • pp.59-64
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    • 1998
  • Kim & Beuermann (1995, 1996)have developed a model for the propagation of X-rays from the accreting white dwarfthrough the infalling material and the re-emission of the energy deposited by photo-absorption in the optical (and UV) spectral range. By using this model, we calculate the profiles of the $H_{\gamma}$ emission-line spectrum of intermediate polars. Photoabsorption of X-ray by the infalling material is the dominant process in forming the observed energy-dependent rotational modulation of the X-ray flux. X-ray and optical modulations are sensitive to model parameters in different ways. In principle, these dependencies allow us to obtain improved insight into the accretion geometry of the intermediate polars. We present results of our calculations and compare them with the $H{\beta}$ line spectrum(Kim & Beuermann 1996).

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Rao-Wald Test for Variance Ratios of a General Linear Model

  • Li, Seung-Chun;Huh, Moon-Yul
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.11-24
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    • 1999
  • In this paper we propose a method to test $\textit{H}$:$\rho_i$=$\gamma_i$ for 1$\leq$$\textit{i}$$\leq$$\ell$ against $\textit{K}$:$\rho_i$$\neq$$\gamma_i$ for some iin k-variance component random or mixed linear model where $\rho$i denotes the ratio of the i-th variance component to the error variance and $\ell$$\leq$K. The test which we call Rao-Wald test is exact and does not depend upon nuisance parameters. From a numerical study of the power performance of the test of the interaction effect for the case of a two-way random model Rao-Wald test was seen to be quite comparable to the locally best invariant (LBI) test when the nuisance parameters of the LBI test are assumed known. When the nuisance parameters of the LBI test are replaced by maximum likelihood estimators Rao-Wald test outperformed the LBI test.

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Initial Mass Function and Star Formation History in the Small Magellanic Cloud

  • Lee, Ki-Won
    • Journal of the Korean earth science society
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    • v.35 no.5
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    • pp.362-374
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    • 2014
  • This study investigated the initial mass function (IMF) and star formation history of high-mass stars in the Small Magellanic Cloud (SMC) using a population synthesis technique. We used the photometric survey catalog of Lee (2013) as the observable quantities and compare them with those of synthetic populations based on Bayesian inference. For the IMF slope (${\Gamma}$) range of -1.1 to -3.5 with steps of 0.1, five types of star formation models were tested: 1) continuous; 2) single burst at 10 Myr; 3) single burst at 60 Myr; 4) double bursts at those epochs; and 5) a complex hybrid model. In this study, a total of 125 models were tested. Based on the model calculations, it was found that the continuous model could simulate the high-mass stars of the SMC and that its IMF slope was -1.6 which is slightly steeper than Salpeter's IMF, i.e., ${\Gamma}=-1.35$.

Some Siegel Threefolds with a Calabi-Yau Model II

  • Freitag, Eberhard;Manni, Riccardo Salvati
    • Kyungpook Mathematical Journal
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    • v.53 no.2
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    • pp.149-174
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    • 2013
  • In a previous paper, we described some Siegel modular threefolds which admit a Calabi-Yau model. Using a different method we give in this paper an enlarged list of such varieties. Basic for this method is a paper of van Geemen and Nygaard. They study a variety $\mathcal{X}$ that is the complete intersection of four quadrics in $\mathbb{P}^7(\mathbb{C})$. This is biholomorphic equivalent to the Satake compactification of $\mathcal{H}_2/{\Gamma}^{\prime}$ for a certain subgroup ${\Gamma}^{\prime}{\subset}Sp(2,\mathbb{Z})$ and it will be the starting point of our investigation. It has been pointed out that a (projective) small resolution of this variety is a rigid Calabi-Yau manifold $\tilde{\mathcal{X}}$. Then we will consider the action of quotients of modular groups on $\mathcal{X}$ and study possible resolutions that admits a Calabi-Yau model in the category of complex spaces.

Manpower Simulation for the Power Plant Design Engineering (발전소 설계 인력 수요의 통계적 분석)

  • Byung Soo Moon;Poong Eil Juhn
    • Nuclear Engineering and Technology
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    • v.14 no.1
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    • pp.1-9
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    • 1982
  • Some observations from the examination of actual manhour curves for the power plant design engineering obtained from Sargent & Lundy Engineers and of a few of the model curves proposed by Bechtel, are analyzed in this paper. A model curve representing typical design engineering manhour has been determined as a probability density function for the Gamma Distribution. By means of this model curve, we strategically forecast the future engineering manpower requirements to meet the Government's long range nuclear power plan. As a sensitivity analysis, the directions for the localization of nuclear power plant design engineering, are studied in terms of the performance factor for the experienced versus inexperienced engineers.

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Antioxidant Effect of Tocopherols and Tocotrienols and cis/trans-, trans/trans-Hydroperoxide Isomer from Linoleic Acid Methylester (토코페롤류의 항산화작용과 Linoleic Acid Methylester에서 생성된 cis/trans-, trans/trans-Hydroperoxide Isomer)

  • Lee, Hyung-Ok
    • Korean Journal of Food Science and Technology
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    • v.25 no.4
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    • pp.307-312
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    • 1993
  • Antioxdant effect was studied in model system with linoleic acid methylester and tocochromanols $({\alpha}-,\;{\beta}-,\;{\gamma}-,\;{\delta}-tocopherol\;and \;{\alpha}-,\;{\gamma}-,\;{\delta}-tocotrienol)$ under definite autoxidation condition-temperature $(40,\;60,\;80^{\circ}C),\;O_2\;(0,\;10,\;20%\;O_2\;in\;N_2)$. 13-Hydroperoxy-9-cis-11-trans-, 13-hydroperoxy-9-trans-11-trans-, 9-hydroperoxy-10-trans-12-cis-, 9-hydroperoxy-10-trans-12-trans-octadecadienoic acid methylester as the major oxidation product were produced from linoleic acid methylester by autoxidation, analyzed with HPLC and antioxidant activities were compared by their quantitative changes. Experimental results showed that all added tocochromanols except ${\alpha}-tocotrienol$ had antioxidant effect at $60^{\circ}C$, and also ${\alpha}-tocopherol$, ${\alpha}-tocotrienol$ and ${\delta}-tocotrienol$ had prooxidant effect at $80^{\circ}C$. And cis/trans-hydroperoxide was predominantly produced at $40^{\circ}C$, but trans/trans-hydroperoxide at $80^{\circ}C$. Except no reproductive experimental data in produced hydroperoxides amount, the production ratio of cis/trans-:trans/trans-hydroperoxides in the autoxidation condition of range from $40^{\circ}C/10%,\;O_2\;to\;60^{\circ}C/20%\;O_2$ were as follows: ${\alpha}-T>{\alpha}-T_3>{\gamma}-T>{\beta}-T>{\gamma}-T_3>{\delta}-T>{\delta}-T_3$. This result showed that ${\alpha}-tocopherol$ among tocochromanols had the lowest antioxidant effect.

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The Changes of Allergenic and Antigenic Properties of Egg White Albumin (Gal d 1) by Gamma Irradiation (감마선 조사된 난백 Albumin(Gal d 1)의 알러지성 및 항원성의 변화)

  • 이주운;육홍선;조경환;이수영;변명우
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.3
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    • pp.500-504
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    • 2001
  • Gamma irradiation was applied to reduce egg allergy. Ovalbumin (OVA), an egg white protein, was used as model allergen and was gamma-irradiated at 3, 5, or 10 kGy in an aqueous state (2.0 mg/mL). The changes in allergenic and antigenic properties of OVA resulted from gamma irradiation were monitored by ELISA with serum from egg-hypersensitive patients (H-IgE), and mouse monoclonal IgG (M-IgG) or rabbit polyclonal IgG (R-IgG). The binding ability of H-IgE to irradiated OVA was dose-dependently reduced. However, IgGs from animal did better recognize 3 or 5 kGy-irradiated OVA. In the evaluation of immune reactivity using blind test, the reactivity of H-IgE rapidly decreased depending upon the irradiation dose. However, the reactivities of M-IgG and R-IgG was higher at 5 and 3 kGy-irradiated OVA than non-irradiated control. The results provide a new possibility to use irradiation process for reducing the allergenicity of egg white.

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Design and Synthesis of Oxime Ethers of β-Oxo-γ-phenylbutanoic Acids as PPAR α and -γ Dual Agonists

  • Han, Hee-Oon;Koh, Jong-Sung;Kim, Seung-Hae;Park, Ok-Ku;Kim, Kyoung-Hee;Jeon, Sang-Kweon;Hur, Gwong-Cheung;Yim, Hyeon-Joo;Kim, Geun-Tae
    • Bulletin of the Korean Chemical Society
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    • v.33 no.6
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    • pp.1979-1982
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    • 2012
  • Oxime ethers of ${\beta}$-oxo-${\gamma}$-phenylbutanoic acids were prepared to develop more effective PPAR ${\alpha}$ and ${\gamma}$ dual agonists. Among them, compound 11k exhibited potent $in$ $vitro$ activities with $EC_{50}$ of 2.5 nM and 3.3 nM in PPAR ${\alpha}$ and ${\gamma}$, respectively. It showed better glucose lowering effects than rosiglitazone 1 and improved the lipid profile like plasma triglyceride in db/db mice model.