• Journal of the Korean Data and Information Science Society
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• 제15권2호
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• pp.379-386
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• 2004

This paper deals with a mixed logit model for vaccination data. The effect of a newly developed vaccine for a certain chicken disease can be evaluated by a noninfection rate after injecting chicken with the disease vaccine. But there are a lot of factors that might affect the noninfecton rate. Some of these are fixed and others are random. Random factors are sometimes coming from the sampling scheme for choosing experimental units. This paper suggests a mixed model when some fixed factors need to have different experimental sizes by an experimental design and illustrates how to estimate parameters in a suggested model.

• 대한한의학회지
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• 제38권4호
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• pp.11-40
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• 2017

Objectives: We investigated whether a mixture of the main component of pomegranate concentrated powder (PCP) with appropriate proportions of Eucommiae Cortex (EC) and Achyranthis Radix (AR) could act synergistically as an effective treatment for osteoarthritis (OA). Methods: In order to evaluate the effects of PCP, EC, and AR against OA, knee thicknesses, maximum extension angle of each knee, anti - inflammation effects, the transcript levels of chondrogenic genes mRNA expressions in femur and tibia articular cartilage (AC) with synovial membrane (SM) were analyzed. In addition, the histopathology and immunohistochemistry of the femur and tibia AC or SM were performed. Results: The surgically-induced OA signs in rats were significantly inhibited by 28 days of continuous treatment of PCP, EC and AR single formulas, and PCP with EC:AR mixed formulas. Especially, PCP with EC:AR 4:1, 2:1 and 1:1 mixed formula treatment constantly showed significantly more favorable inhibitory activities, as compared with those of single formula of PCP, EC and AR treated rats. Conclusion: PCP and EC:AR 4:1 mixed formula showed similar OA refinement effects through potent anti-inflammatory pathways as compared with those of diclofenac treatment, and showed additional chondrocyte proliferating effects on the both femur and tibia AC.

• 한국안광학회지
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• 제1권1호
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• pp.1-14
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• 1996

Magic-Angle-Spinning NMR에 나타나는 $Li^+$ 이온의 운동과 관련된 알칼리 혼합 효과에 미치는 전이금속 산화물의 영향을 조사하기 위하여 불순물 $Fe_2O_3$를 0.1 mol% 첨가시킨 혼합 알칼리 Silicate 유리들을 제조하였고, 온도에 따라 $^7Li$ MAS-NMR 스펙트럼과 상온에서 $^7Li$ 스핀-살창 완화시간을 측정하였다. $Fe_2O_3$가 첨가되었을 때, 스펙트럼의 선폭이 조금 변화되었을 뿐이며 선 모양이 거의 변하지 않고 있다. 이 때문에, 스핀-스핀 완화 과정에서는 혼합 알칼리 효과가 충분히 나타나는 것으로 불수도 있지만 반드시 그렇지만은 않아 보인다. $Li^+$ 이온의 활성화 에너지가 혼합 알칼리 유리에서 오히려 감소하는 경향이 나타났다. 이것은 혼합 알칼리 효과가 아니다. 스핀-살창 완화시간, 완화 과정 분석을 통한 $Li^+$ 이온의 확산 환경, 그리고 핵 자가화 (nuclear magnetization) 등의 비교에 의하면, $^7Li$ 스핀-살창 완화 과정에서 알칼리 혼합 효과는 거의 나타나지 않는 것을 확인 할 수 있었다.

• 한국수소및신에너지학회논문집
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• 제18권1호
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• pp.75-84
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• 2007

The effects of hydrogen enrichment to methane on NOx formation have been investigated with swirl stabilized pre-mixed hydrogen enriched methane flame in a laboratory-scale pre-mixed combustor(nominally of 5,000 kcal/hr). The hydrogen enriched methane fuel and air were mixed in a pre-mixer and introduced to the combustor through different degrees of swirl vanes. The flame stability was examined for different amount of hydrogen addition to the methane fuel, different combustion air flow rates and swirl strengths by comparing equivalence ratio at the lean flame limit. The hydrogen addition effects and swirl intensity on the combustion characteristics of pre-mixed methane flames were examined using gas analyzers, and OH chemiluminescence techniques to provide information about species concentration of emission gases and flowfield. The results of NOx and CO emissions were compared with a diffusion flame type combustor. The results show that the lean stability limit depends on the amount of hydrogen addition and the swirl intensity. The lean stability limit is extended by hydrogen addition, and is reduced for higher swirl intensity at lower equivalence ratio. The addition of hydrogen increases the NOx emission, however, this effect can be reduced by increasing either the excess air or swirl intensity. The NOx emission of hydrogen enriched methane premixed flame was lower than the corresponding diffusion flame under the fuel lean condition.

• Communications for Statistical Applications and Methods
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• 제20권3호
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• pp.235-240
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• 2013

Generalized linear mixed models(GLMMs) are frequently used for the analysis of longitudinal categorical data when the subject-specific effects is of interest. In GLMMs, the structure of the random effects covariance matrix is important for the estimation of fixed effects and to explain subject and time variations. The estimation of the matrix is not simple because of the high dimension and the positive definiteness; subsequently, we practically use the simple structure of the covariance matrix such as AR(1). However, this strong assumption can result in biased estimates of the fixed effects. In this paper, we introduce Bayesian modeling approaches for the random effects covariance matrix using a modified Cholesky decomposition. The modified Cholesky decomposition approach has been used to explain a heterogenous random effects covariance matrix and the subsequent estimated covariance matrix will be positive definite. We analyze metabolic syndrome data from a Korean Genomic Epidemiology Study using these methods.

• 방사성폐기물학회지
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• 제19권1호
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• pp.141-160
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• 2021

Unit 1 of the Kori Nuclear Power Plant (NPP) and Unit 1 of the Wolsong NPP are being prepared for decommissioning; their decommissioning is expected to generate large amounts of intermediate-level, low-level, and very low level Waste. Mixed waste containing both radioactive and hazardous substances is expected to be produced. Nevertheless, laws and regulations, such as the Korean Nuclear Safety Act and Waste Management Act, do not define clear regulatory guidelines for mixed waste. However, the United States has strictly enforced regulations on mixed waste, focusing on the human health and environmental effects of its hazardous components. The U.S. Nuclear Regulatory Commission and the U.S. Department of Energy regulate the radioactive components of mixed waste under the Atomic Energy Act. The U.S. Environmental Protection Agency regulates the hazardous waste component of mixed waste under the Resource Conservation and Recovery Act. In this study, the laws, regulations, and authorities pertaining to mixed waste in the United States are reviewed. Through comparison and analysis with waste management laws and regulations in Korea, a treatment direction for mixed waste is suggested. Such a treatment for mixed waste will increase the efficiency of managing mixed waste when decommissioning NPPs in the near future.

• Journal of Acupuncture Research
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• 제31권4호
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• pp.45-55
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• 2014

Objectives : The main aim of this study was to assess the comparative efficiency of two preparation types of Hwangryunhaedok decoction(HRHD-D) using distilled and mixed extraction by measuring the index components and indicators of antioxidant and anti-inflammatory effects. Methods : The antioxidant activity was assessed by comparing distilled and mixed extractions of HRHD-D using an ELISA reader. The anti-inflammatory effect was determined by measuring NO amounts in RAW 264.7 cells. The contents were analyzed with high performance liquid chromatography-diode array detector(HPLC-DAD). Results : The electron donating ability of mixed and distilled extractions obtained with 500 ppm DPPH(1,1-diphenyl-2-picrylhydrazyl assay) solution were 57.8 % and 4.2 %, respectively. The total phenolic content of mixed extraction was 6.9 times that of distilled extraction and total flavonoid content was 51.5 times higher. The anti-inflammatory effect was assessed by NO measurement, and was found to increase significantly dependent on concentration in all mixed extract concentrations(25, 50, 100, 200, $400{\mu}g/mL$), but the difference in distilled extraction by concentration was only significant at 200 and $400{\mu}g/mL$. The HPLC analysis results of mixed extract of HRHD-D showed detection of all four main active constituents of HRHD-D. However, they were not detected in the distilled extract of HRHD-D. Conclusions : Mixed extraction with distillation added to decoction of HRHD-D showed better efficacy in antioxidant and anti-inflammatory effects, and ingredient quantities compared to distilled extraction. Further stability and clinical efficacy studies for standardization of mixed extractions are required.

• 한국식품영양과학회지
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• 제23권4호
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• pp.548-554
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• 1994

In order to observe the effects of the feeds mixed with the lard and two vegetable seed oils on the fatty acid compositions of serum lipkid and lipoprotein, the oils mixed with 2.5% lard and various levels of perilla oil and evening promrose oil were administered to the male rats of the Sprague-DAwley for 4 weeks. In the fatty acid compositions of serum lipid and serum lipoprotein fractions, as the content so f mixed perilla oil decreased and the contents of mixed evening primrose oil increased, n -3 PUFa (polyunsaturated fatty acid) contents and ratio of EPA/AA (eicisapentaenoiidacid/arachidonic acid) tended to decrease, but n-6 PUFA contents and ratio of AA/PUFA tended to increase. Fatty acid compositions of serum lipid and serum lipoprotein fractions were influenced from the fatty acid composition of the test lipids.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.604-609
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• 2001

This numerical analysis uses the lifting surface method and frequency-domain panel method based on the linear compressible aerodynamic theory. Increased knowledge of flow conditions within mixed-flow fan should indicates means of improving performance of these turbomachines. Thus, only an approximate solution is obtained whose prime intent is to recognize the most significant characteristics of the "ideal" geometry. For a given set of operating condition, the flow conditions within mixed-flow fan depend on the geometry of the machine (three-dimensional flow effects) and on the properties of the fluid. But most treatments of the problem have been concerned with the two-dimensional flow effects for incompressible, non-viscous fluids. Interest in the field of mixed-flow fan resulted in the undertaking of a program to develop reliable design procedures that would avoid the need for lengthy development work.

• Membrane and Water Treatment
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• 제11권4호
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• pp.237-245
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• 2020

The effects of the mixed two solvents, Dimethylacetamide (DMAc) and Dimethylformamide (DMF), and Polyethylene glycol (PEG) and Polyvinylpyrrolidone (PVP) as additives on performance of Polyvinylidene fluoride (PVDF) membranes were studied. Initially, PEG200 was used as a primary additive at fixed percentage of 5% wt. PVP was then blended with PEG200 in different concentrations. PVDF and DMAc were used as polymer and solvent in the casting solutions, respectively. To control the diffusion rate of PVP in the presence of PEG200 and PVP blend, mixtures of DMAc and DMF were used as the mixed solvent in the casting solutions. Asymmetric PVDF membranes were prepared via phase inversion process in a water bath and the effects of two additives and two solvents on the membrane morphology, pure water flux (PWF), hydrophilicity and rejection (R) were investigated. Attenuated Total Reflection Fourier Transform Infrared Spectra (ATR-FTIR) analysis was used to show the residual PVP on the surface of the membranes. Atomic Force Microscopy (AFM) was utilized to determine roughness of membrane surface. The use of mixed solvents in the casting solution resulted in reduction of PVP diffusion rate and increment of PEG diffusion rate. Eventually, PWF and R values reduced, while porosity and hydrophilicity increased.