• 품질경영학회지
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• 제33권4호
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• pp.111-116
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• 2005

This paper considers the problem of optimally choosing the sub-process means of a mixture production process where two important ingredients are mixed. The quantity of each ingredient is controlled through each corresponding sub-process. The values of the sub-process mean directly affect the defective rate, production, scrap and reprocessing costs for the mixture production process. After inspecting every incoming item, each conforming item is sold in a regular market for a fixed price and any nonconforming item is scraped. A model is constructed on the basis of the selling price, production, inspection, and scrap and reprocessing costs. The goal is to determine the optimum sub-process mean values based on maximizing expected profit function relating selling price and cost components. A method of finding the optimum sub-process means is presented when the quantities of the two ingredients are assumed to be normally distributed with known variances. A numerical example is given and numerical studies are performed.

• Computers and Concrete
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• 제9권2호
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• pp.119-131
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• 2012

Optimum packing of aggregate is an important aspect of mixture design, since porosity may be reduced and strength improved. It may also cause a reduction in paste content and is thus of economic relevance too. Several mathematic packing models have been developed in the literature for optimization of mixture design. However in this study, numerical simulation will be used as the main tool for this purpose. A basic, simple theoretical model is used for approximate assessment of mixture optimization. Calculation and simulation will start from a bimodal mixture that is based on the mono-sized packing experiences. Tri-modal and multi-sized particle packing will then be discussed to find the optimum mixture. This study will demonstrate that computer simulation is a good alternative for mixture design and optimization when appropriate particle shapes are selected. Although primarily focusing on aggregate, optimization of blends of Portland cement and mineral admixtures could basically be approached in a similar way.

• 한국농공학회지
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• 제22권3호
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• pp.46-59
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• 1980

This study was conducted to obtain the most effective distribution of grain size and the optimum lime content for lime-soil stabilization. To achieve the aim, the change of consistency, the characteristics of compaction and unconfined compressive strength were tested by adding of 0, 4, 6, 8, 10 and 12 percent lime by weight for all soils adjusted by given ratios of sand to clay. The results obtained were as follows; 1. There was a tendency that the plasticity index of lime-soil mixture was decreased by increasing the amount of lime, whereas the liquid limit was varied irregularly and the plastic limit was increased. 2. With the addition of more lime, the optimum moisture content of lime-soil mixture was increased, and the maximum dry density was decreased. 3. The optimum lime content of lime-soil mixture was varied from soil to soil, and the less amount of small grain size, the less value of optimum lime content. 4. The optimum distribution of grain size for lime-soil mixture was in the soil, having the ratio of about 60 percent of cohesive clay and about 40 percent of sand by weight. 5. In the soil having fine grain size, the effect of curing appeared for long periods of time, whereas the increasing rate of unconfined compressive strength was great on the soil of coarse grain size in the earlier stage of curing period.

• 산업기술연구
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• 제22권A호
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• pp.83-87
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• 2002

Many industrial products such as paints, ink and adhesives are composed of the ingredients of a mixture. In mixture experiments, the characteristics of quality(response) depends only on the proportions of the ingredients and does not depend on the total amount of the mixture. This article discusses the constrained mixture experimental design, the data analysis, and the optimum formulation of ingredients based on the two quality characteristics - taste and flavor. It IS shown that efficient designs can be constructed from D-optimal criterion. Special cubic models were selected as the final mixture response surfaces for both reponses. The desirability function was used for the optimization of the two responses.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.37-38
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• 2023

As one of the resource recovery projects, this study aims to select natural fibers and synthetic fibers that can be used for concrete mixing among waste fibers and reuse them for the base concrete mixture. Using waste fiber, we seek a solution to the problem of reduced fluidity and hardening time of fiber-reinforced concrete and find the optimal mix of the ground concrete mixed with waste fiber.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.525-528
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• 2005

This study determines the best composite grade to minimize the void of aggregate mixture based on the maximum density theory in an attempt to suggest a mix proportion method design for asphalt mixtures. Study results show that the grading curve with the maximum mass per unit capacity of each aggregate mixture satisfied the KS standards and the optimum AP content to meet the optimal asphalt mixture void rate of 4$\%$ was 5.7$\%$, less than the optimum AP content of 6.5$\%$ suggested in the Marshal mix proportion method design. At the same time, the asphalt mixture produced based upon the suggested mix proportion method had a flow value 17$\%$ lower than that of asphalt mixture produced according to the Marshal method, while its density was greater by 0.06$\～$0.09. This suggests that the introduced mix proportion method design helps to improve the shape flexibility and crack-resistance of asphalt concrete.

• 산업공학
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• 제18권4호
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• pp.402-411
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• 2005

Secondary batteries with high performance are essential in widespread use of modern portable devices such as cellular phones and laptop computers. High energy density, long cycle life, and safety are some of important requirements for secondary battery. To achieve such characteristics, a mixing proportion of electrolyte solution ingredients in the battery should be carefully chosen. In this paper, using statistical design of mixture experiments (DOME), we attempt to find an optimum condition of designing the secondary battery. DOME has a distinct feature in that the experimental region is represented by simplex, rather than hypercube, because the sum of blend proportions should be unity. Several designs based upon this point have been proposed for mixture experiments. Among them, an extreme vertices design is employed in this paper because there are a couple of blend constraints to be considered. In order to investigate how the mixing proportion interacts with other manufacturing factors, a fractional factorial design is also included across the extreme vertices design. As a result, we find that the blend proportion of solution ingredients has a significant effect on battery performances. By simultaneously optimizing two battery capacities, this paper proposes an optimum blend proportion according to process factor settings.

• 한국도로학회논문집
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• 제15권4호
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• pp.43-51
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• 2013

PURPOSES : The main purposes of this study are to examine the influences of polyethylene wax-based WMA additive on the optimum asphalt content of warm-recycled asphalt mixture based on the Marshall mix design and to evaluate performance of warm-recycled asphalt mixture containing 30% RAP with polyethylene wax-based WMA additive. METHODS: Physical and rheological properties of the residual asphalt were evaluated in terms of penetration, softening point, ductility and performance grade (PG) in order to examine the effects of polyethylene wax-based WMA additive on the residual asphalt. Also, To evaluate performance characteristics of the warm-recycled asphalt mixtures using polyethylene wax-based WMA additive along with a control hot-recycled asphalt mixture, indirect tensile strength test, modified Lottman test, dynamic immersion test, wheel tracking test and dynamic modulus test were conduced in the laboratory. RESULTS : Based on the limited laboratory test results, polyethylene wax-based WMA additive is effective to decrease mixing and compacting temperatures without compromising the volumetric characteristics of warm-recycled asphalt mixtures compared to hot-recycled asphalt mixture. Also, it doesn't affect the optimum asphalt content on recycled-asphalt mixture. All performance test results show that the performance of warm-recycled asphalt mixture using polyethylene wax-based WMA additive is similar to that of a control hot-recycled asphalt mixture. CONCLUSIONS: Overall, the performance of warm-recycled asphalt mixture using polyethylene wax-based WMA additive is comparable to hot-recycled asphalt mixture.

• 한국농공학회지
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• 제44권5호
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• pp.88-95
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• 2002

This study is a fundamental research for recycling waste vinyl (WV) in asphalt mixture for improving roadway pavement. Mix design was conducted by WV content and optimum asphalt content (OAC) was determined for dense-graded surface course mixture. Marshall stability test, indirect tensile strength (ITS) test and wheel tracking test were carried out to measure the characteristics of WV-added asphalt concretes. From the results of this study, recycling WV in asphalt mixture is possible. However, as WV content increased, melted WV clustering appeared in asphalt mixture. It could be considered that adding too much WV in asphalt mixture is not proper. The proper content of LDPE and HDPE WV was appeared to be 12% and 8%, respectively.

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.333-338
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• 1999

This study was aimed to develop a value-added fermented products from rice and apple pomace using Bifidobacterium fermentation. The Bifidobacterium fermentation system of the mixture of rice and apple pomace was developed, and the physicochemical properties of the products were investigated. After 4 different bifidobacteria were compared for their fermentation capability and sensory properties of the fermented product, Bifidobacterium FBD-13 and FBD-22 were selected as appropriate strains for the fermentation of saccharified rice solution(SRS). The optimum inoculation level was 2% and the optimum fermentation time was 42 hrs. When wet apple pomace(WAP) was added to SRS, it contributed to the improvement of sensory properties of the fermented products and the optimum mixing ratio was 40% WAP and 60% SRS in weight. For the fermentation of the mixture of WAP and SRS, Bifidobacterium FBD-27 and FBD-22 were selected as suitable strains.