• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.239-250
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• 1998

A method of finding optimal linear restriction on regression parameters in linear model for mixture experiments in the sense of minimizing integrated mean squared error is studied. We use the formulation of optimal restrictions on regression parameters for estimating responses proposed by Park(1981) by transforming mixture components to mathematically independent variables.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.491-494
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• 2004

With recent experiments to add He atoms to the Ne-Xe discharge gas mixture for high luminous efficiency PDPs, we have performed simulations on a coplanar structured AC-PDP sustained in the three species He-Ne-Xe gas mixture. We found that the correct ion mobilities are essential to get the meaningful simulation results. We determined ion mobilities in the mixture gas and presented the calculated results regarding the influence of ion mobilities on discharge characteristics.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.269-274
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• 2001

This paper describes the experimental results on direct selective laser sintering of WC-Co mixture. The experiments were carried out within an air, argon and nitrogen atmosphere. The main problem occurred during sintering within an air atmosphere was oxidation of WC-Co mixture. As the power of laser is increased and scanning speed is decreased, more severe oxidation takes place. Within an argon and nitrogen atmosphere the oxidation is reduced significantly. As the energy density is increased the thickness of the sintered layer is increased.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.1-11
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• 2002

This paper discusses problems of the Poisson Mixture model which Is widely used to decide the effective words in judging relevant document. Gamma Distribution model and Gauss Patterns model as an alternative of the Poisson Mixture model are studied. Classification experiments by using TREC sub-collection, WSJ[1,2] with MGQUERY and AidSearch3.0 system are discussed.

• Communications for Statistical Applications and Methods
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• v.14 no.3
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• pp.687-698
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• 2007

A normal mixture model with which dependence between classes is incorporated is proposed in order to detect differentially expressed genes. Gene clustering approaches suffer from the high dimensional column of microarray expression data matrix which leads to the over-fit problem. Various methods are proposed to solve the problem. In this paper, use of simple averaging data within each class is proposed to overcome the various problems due to high dimensionality when the normal mixture model is fitted. Some experiments through simulated data set and real data set show its availability in actuality.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.231-234
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• 2004

The experiments on some organic materials used in SAPS are carried out for the better sulfate reduction efficiency and the longer lifetime. Organic materials include spent mushroom compost, sewage sludge, oak chip compost and the combination of there. Reactors with mushroom compost, sewage sludge, the mixture of mushroom compost and sewage sludge, and the mixture of mushroom compost and oak chip compost maintained pH higher than 6.0. Reactors with mushroom compost, the mixture of mushroom compost and sewage sludge, and the mixture of mushroom compost and oak chip compost maintained reduction condition. Reactors with sewage sludge, oak chip compost and the mixture of sewage and oak chip compost produced COD less than 2,000ppm. Reactors with sewage and the mixture of mushroom compost, sewage sludge, oak chip compost showed about 60% of sulfate removal ratios.

• Progress in Superconductivity and Cryogenics
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• v.10 no.4
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• pp.38-42
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• 2008

Miniature J-T cryocooler using nitrogen or argon has been widely adopted in cooling infrared sensor for space/military application and cryosurgery. Argon or nitrogen, however, has relatively low specific cooling power compared to nitrous oxide, but the ultimate operating temperature is much lower than nitrous oxide. On the other hand, nitrous oxide has large specific cooling power, but the operating temperature is limited to its boiling point (>183K). To compromise the different characteristics of these gases, the performance of miniature J-T cryocooler using argon and nitrous oxide mixture is investigated in this paper. Three different compositions of mixture (25/75, 50/50, and 75/25 molar fraction) are blended and tested. The results are compared with the experiments of pure argon and pure nitrous oxide. The experimental results show some encouraging potentiality of mixed refrigerant J-T cryocooler. The critical clogging problem, however, was observed with argon and nitrous oxide mixture, and the lowest achievable temperature with this mixture was limited to the freezing point of nitrous oxide. The paper discusses detailed clogging process of the mixture and suggests an alternative.

• Biomedical Science Letters
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• v.26 no.4
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• pp.296-301
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• 2020

The purpose of this study was performed to evaluate antioxidant activity of the Artemisia asiatica Nakai and Moringa oleifera Lam mixture extract. Mixture extracts were manufactured by concentration and compared with a single extract (only the Artemisia asiatica Nakai mixture and only the Moringa oleifera Lam mixture). The experiments conducted Total polyphenol measurements, Total flavonoid measurements, DPPH radical scavenging activty, ABTS radical scavenging activty and LDH assay. The LDH assay assessment shows that all extracts are cells compared to controls. The toxicity was weak. Finally, The antioxidant capacity was rated higher than mixture extract of a single extract. Also, the optimized mixture was determined AM5 (Artemisia asiatica Nakai mixture: Moringa oleifera Lam mixture = 3:1). For extracts of AM5, Total phenol and flavonoid contents were 271.769±18.087 mg/g and 45.384±5.026 mg/g. and DPPH and ABTS scavenging activity were 70.8±6.496% and 77.1±9.634%. Therefore, it is expected that the value of the extract will increase as it increases its antioxidant activity if it is manufactured according to the appropriate ratio.

• Journal of the Korean Applied Science and Technology
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• v.41 no.2
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• pp.318-328
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• 2024

In this study, we enhanced the emulsifying power and solubilization of sucrose stearate (SS) by creating mixtures with sodium deoxycholate (SDOC) and PEG-40 hydrogenated castor oil (HCO). We employed the design of mixture experiments (DOME) methodology to identify the optimal composition of the mixture, and the impact of varying the mixture composition on its characteristics was examined through regression analysis of the experimental data. It was revealed that the emulsifying power for coconut oil was most improved when only SDOC was added to SS, and solubilization was most improved when only HCO was added, while the emulsifying power for cetyl ethylhexanoate (CEH) was most significantly improved when SDOC and HCO were added together. As a result of simultaneous optimization of three characteristics, emulsifying power for each of coconut oil and CEH, and solubilization, the optimal surfactant mixture composition was determined as SS 0.7939, SDOC 0.0586, and HCO 0.1475.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.881-892
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• 2016

Following the Fukushima accident and its extended station blackout, attention was brought to the importance of the spent fuel pools' (SFPs) behavior in case of a prolonged loss of the cooling system. Since then, many analytical works have been performed to estimate the timing of hypothetical fuel uncovery for various SFP types. Experimentally, however, little was done to investigate issues related to the formation of a flammable gas mixture, distribution, and stratification in the SFP building itself and to some extent assess the capability for the code to correctly predict it. This paper presents the main outcomes of the Experiments on Spent Fuel Pool (ESFP) project carried out under the auspices of Swissnuclear (Framework 2012-2013) in the PANDA facility at the Paul Scherrer Institut in Switzerland. It consists of an experimental investigation focused on hydrogen concentration build-up into a SFP building during a predefined scaled scenario for different venting positions. Tests follow a two-phase scenario. Initially steam is released to mimic the boiling of the pool followed by a helium/steam mixture release to simulate the deterioration of the oxidizing spent fuel. Results shows that while the SFP building would mainly be inerted by the presence of a high concentration of steam, the volume located below the level of the pool in adjacent rooms would maintain a high air content. The interface of the two-gas mixture presents the highest risk of flammability. Additionally, it was observed that the gas mixture could become stagnant leading locally to high hydrogen concentration while steam condenses. Overall, the experiments provide relevant information for the potentially hazardous gas distribution formed in the SFP building and hints on accident management and on eventual retrofitting measures to be implemented in the SFP building.