• Title/Summary/Keyword: PP model

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A Repository Model of Security Environment Contents based on CC (CC 기반의 보안환경 컨텐츠 리파지토리 모델)

  • Choi Sang-Soo;Bang Young-Hwan;Lee Gang-Soo
    • Journal of Digital Contents Society
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    • v.5 no.2
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    • pp.157-162
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    • 2004
  • A development of PP/ST is essential in CC environment. And, the KOREA is expected that PP/STs demand increases explosively by joining to CCRA hereafter. Specially, PP/ST development experience of the KOREA is lacking. So, development of security environment(assume, threat, policy) and security objective contents refer only PP/ST Guide(ISO/IEC PDTR 15446) are very difficult. In this paper, we propose a web service based common security environment and security objective repository model that make developers can run PP/ST creation to be simple. Through proposed model, developers who development experience is lacking are expected to achieve PP/ST development to be simple.

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Performance of VaR Estimation Using Point Process Approach (점과정 기법을 이용한 VaR추정의 성과)

  • Yeo, Sung-Chil;Moon, Seoung-Joo
    • The Korean Journal of Applied Statistics
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    • v.23 no.3
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    • pp.471-485
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    • 2010
  • VaR is used extensively as a tool for risk management by financial institutions. For convenience, the normal distribution is usually assumed for the measurement of VaR, but recently the method using extreme value theory is attracted for more accurate VaR estimation. So far, GEV and GPD models are used for probability models of EVT for the VaR estimation. In this paper, the PP model is suggested for improved VaR estimation as compared to the traditonal EV models such as GEV and GPD models. In view of the stochastic process, the PP model is regarded as a generalized model which include GEV and GPD models. In the empirical analysis, the PP model is shown to be superior to GEV and GPD models for the performance of VaR estimation.

Experimental and Theoretical Study on Shear Flow Behavior of Polypropylene/Layered Silicate Nanocomposites

  • Lee, Seung-Hwan;Youn, Jae-Ryoun
    • Advanced Composite Materials
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    • v.17 no.3
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    • pp.191-214
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    • 2008
  • Polypropylene/layered silicate nanocomposites containing maleic anhydride grafted polypropylene were prepared by melt compounding and their rheological behavior was investigated in shear flow. Transient and steady shear flows were simulated numerically by using the K-BKZ integral constitutive equation along with experimentally determined damping functions under dynamic oscillatory and step strain shear flows. Nonlinear shear responses were predicted with the K-BKZ constitutive equation using two different damping functions such as the Wagner and PSM models. It was observed that PP-g-MAH compatibilized PP/layered silicate nanocomposites have stronger and earlier shear thinning and higher steady shear viscosity than pure PP resin or uncompatibilized nanocomposites at low shear rate regions. Strong damping behavior of the PP/layered silicate nanocomposite was predicted under large step shear strain and considered as a result of the strain-induced orientation of the organoclay in the shear flow. Steady shear viscosity of the pure PP and uncompatibilized nanocomposite predicted by the K-BKZ model was in good agreement with the experimental results at all shear rate regions. However, the model was inadequate to predict the steady shear viscosity of PP-g-MAH compatibilized nanocomposites quantitatively because the K-BKZ model overestimates strain-softening damping behavior for PP/layered silicate nanocomposites.

Studies for the Sustainable Management of Oyster Farms in Pukman Bay, Korea: Estimate of Primary Production

  • Jeong, Woo-Geon;Cho, Sang-Man;Lee, Sang-Jun
    • Fisheries and Aquatic Sciences
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    • v.12 no.2
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    • pp.111-117
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    • 2009
  • To develop sustainable management strategies for oyster farms in Pukman Bay, Korea, we estimated primary production using a numerical model. Because oysters are filter feeders, estimations of primary production (PP) are essential in developing management strategies. The daily PP ranged from 0.07 to 1.5 gC/$m^2$/d and showed significant spatial variations. The spatial distribution of PP was strongly associated with hydrodynamic features, and distinct patterns were observed in three different regions. In the inner bay, high PP was directly influenced by urban and agricultural sewage. The middle part of the bay had low PP, whereas PP in the outer area was high. PP was relatively low during the main oyster growth season, from late autumn to early winter. These findings represent important information for developing a management model for oyster farms in Pukman Bay.

Accuracy Comparison of Existing 3 Models in Estimating Time-Varying Variance of Phase Deviation of a Simple Planar Oscillator (간단한 평면 오실레이터의 위상 천이의 시변 분산에 대한 기존 3개 모델의 추정 정확도 비교)

  • Jeon, Man-Young
    • Journal of IKEEE
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    • v.19 no.4
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    • pp.500-505
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    • 2015
  • Through Montecarlo simulation, this study compares how accurately the existing three phase deviation models estimate the time-varying variance of a planar oscillator perturbed by Gaussian noises. The comparison reveals that Kaertner model estimates the time-varying variance with about 1000 times higher accuracy than ISF or PP model exhibits. Additionally, it finds that the estimation accuracy of PP model is somewhat higher than that of ISF model.

Flow Properties of Traditional Kochujang : Effect of Fermentation Time (숙성기간에 따른 재래 고추장의 유동성 변화)

  • 유병승;최원석;류영기
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.3
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    • pp.554-558
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    • 1999
  • Flow properties of traditional kochujang at various fermentation times(0~12 weeks) were determined with rotational cylindrical(RC) and serrated plate plate(PP) viscometer. Magnitudes of consistency index(K) of power law model and Cassson parameters(yield stress and viscosity) measured by PP viscometer were higher than those using RC viscometer. All kochujang samples during fermentation were much shear thinning with values of flow behavior index(n) as low as 0.2~0.34. K value and Casson yield stress measured by PP viscometer had good correlations(r=0.94; r=0.91) with fermentation time. No significant changes in flow model parameters measured by RC viscometer were observed for kochu jang during fermentation. Magnitudes of flow model parameters measured by PP viscometer more closely correlated with fermantation times of kochujang than did RC viscometer.

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XPS Study of Mn 2pp and 3s Satellite Structures of Heusler Alloys: NiMnSb, ppdMnSb, pptMnSb

  • Yang, See-Hun;Oh, Se-Jung;ppark, Je-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 1994.02a
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    • pp.50-50
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    • 1994
  • Half-metallic Heusler alloys (NiMnSb, ppdMnSb, pptMnSb) have attracted much attention due to their unique electronic and magnetic structures. Sppin-ppolarized band structure calculation ppredicts metallic behavior for the majority sppin states and semiconductor behavior for the minority sppin states. We have studied the electronic structures of these half-metallic Heusler alloys by core-level pphotoemission sppectroscoppy of Mn 2pp and 3s XppS sppectra. We found large intensities of Mn 2pp satellites and 3s exchange spplitting comppared with other metal Mn-alloys. These satellite structure can be understood by applying Anderson imppurity model. This fact supports the calculated sppin pprojected ppartial density of states which suggests that the valence electrons be highly sppin ppolarized near Fermi level and that the electrons involved with charge-transfer be mainly minority sppin ones which have semiconducting band structure. The trend of charge transfer energies Δ from ligands (Sb 5pp) to Mn 3d, obtained from our model fitting, is consistent with that calculated from sppin pprojected ppartial density of state. Also the trend of d-d electron correlation energies U calculated from Mn Auger line L3 VV by Mg $K\alpha$ source is comppatible with that resulted from our model fitting. We fitted the Mn 3s curve in the same way as for insulating Mn comppounds by using the same pparameters calculated from Mn 2pp curve fitting exceppt for the Coulomb interaction energy Q between core hole and d-electrons. The 3s sppectra were analyzed by combing the charge transfer model and a simpple model taking into account the configuration mixing effect due to the intra-shell correlation. We found that the exchange interaction between 3s hole and 3d electrons is mainly respponsible for the satellite of Mn 3s sppectra. This is consistent with the neutron scattering data, which suggests local 3d magnetic moment. We find that the XppS analysis results of Mn 2pp and 3s satellite structures of half-metallic Heusler alloys are very similar to those of insulating transition metal comppounds.

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Regulation of type-1 protein phosphatase in a model of metabolic arrest

  • Ramnanan, Christopher J.;Storey, Kenneth B.
    • BMB Reports
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    • v.42 no.12
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    • pp.817-822
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    • 2009
  • Type-1 phosphatase (PP-1) was assessed in foot muscle (FM) and hepatopancreas (HP) of estivating (EST) Otala lactea. Snail PP-1 displayed several conserved traits, including sensitivity to inhibitors, substrate affinity, and reduction in size to a 39 kDa catalytic subunit (PP-1c). During EST, PP-1 activity in FM and HP crude extracts was reduced, though kinetics and protein levels of purified PP-1c isoforms were not altered. PP-1c protein levels increased and decreased in nuclear and glycogen-associated fractions, respectively, during EST. Gel filtration determined that a 257 kDa low $K_m$ PP-1$\alpha$ complex decreased during estivation whereas a 76 kDa high $K_m$ complex increased in EST. Western blotting confirmed that the 76 kDa protein consisted of PP-1$\alpha$ and nuclear inhibitor of PP-1 (NIPP-1). A suppression of PP-1 activity factors in the overall metabolic rate depression in estivating snails and the mechanism is mediated through altered cellular localization and interaction with binding partners.

Protective effects of Paeoniae Radix Alba and Puerariae Radix combination on alcoholic liver disease (알코올성 간 손상 동물 모델에서 芍藥 葛根 복합물의 간 손상 보호 효과)

  • Jeong Won, Choi;Jin Young, Kim;Mi-Rae, Shin;Hae-Jin, Park
    • The Korea Journal of Herbology
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    • v.38 no.1
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    • pp.31-43
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    • 2023
  • Objective : Alcoholic liver disease (ALD) is caused by excess alcohol intake. In the liver, alcohol breakdown results formation of toxic byproducts that lead to damage to tissue. This study is to investigate the therapeutic effects of Paeoniae Radix Alba and Puerariae Radix combination (PP) on ALD. Methods : PP was analyzed for polyphenolic compounds and free radical scavenging activity. ALD mouse model was induced by feeding ethanol and water (Control), silymarin (50 mg/kg), low-dose (PP: 100 mg/kg) or high-dose (PP: 200 mg/kg) was orally administrated to ALD mice for 14 days. The serum was assessed with levels of AST, ALT, total bilirubin, total cholesterol, and triglyceride. Liver tissues were evaluated for ROS levels, degree of liver damage and protein expression. Results : The 3:1 (Paeoniae Radix Alba:Puerariae Radix) ratio showed the best antioxidant values for the experiment. In ALD model, levels of AST, ALT, total bilirubin, total cholesterol, and triglyceride were significantly increased in the Control and the levels were decreased by treatment of PP. In addition, increased ROS, ONOO- and MDA levels in the Control were reduced in the PP groups. Western blot analysis figured out that proteins related to ROS and cholesterol metabolism were higher in ALD than in PP-treated ALD. Antioxidant enzyme expression was low in the control group and increased by PP treatment. Conclusion : Our results suggest that PP has the potential to be a medicine in ALD in terms of regulating oxidative stress and adjusting lipid metabolism.