• Corrosion Science and Technology
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• 제6권2호
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• pp.68-73
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• 2007

The toxicity of chromium that is used to impart corrosion resistance to galvanized steel created environmental and health-related concerns and generated a great deal of interest in developing chrome-free treatment coatings. In the present work, organic-inorganic composite coatings were used to coat electrogalvanized steel (EG) sheets for corrosion protection without degrading its weldability property. The new coatings composed of specially modified polyurethane dispersion hybridized with silicate and unique inorganic-organic inhibitors were developed during this work. It was found that about $1{\mu}m$ thickness of coating layer is secure enough in corrosion resistance of flat and formed part even after alkaline degreasing. Overall chemical resistances including fingerprint resistance and paint adhesion property were satisfied with the test specification of Sony technical standard of SS-00260-2002. Therefore, it is concluded that the newly developed chrome-free product can replace the conventional chromated product.

• 대한산업공학회지
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• 제14권2호
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• pp.81-90
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• 1988

This paper is concerned with warranty cost models for a product with two types of failure ; type 1 failures corrected by minimal repair and type 2 failures removed only by replacement. Two warranty policies involving an initial free service period followed by a pro-rata period are considered ; the difference is whether the warranty is renewed or not when type 2 failure occures during its free service period. Expected warranty costs under the two policies are obtained, and their behaviors are examined for the case where type 1 and 2 failure distributions are Weibull and exponential, respectively.

• 품질경영학회지
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• 제40권4호
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• pp.441-452
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• 2012

Purpose: In this paper, we have considered a problem of newsvendor model in an environment of random yields in quality and customer balking behavior, in which only the mean and the variance of the demand are known. In practice, the distributional information of the demand is very limited and only the mean and variance are guessed by experience. In addition, due to the customers balking behavior occurring when the available inventory level decreases, the product's demand becomes a function of inventory level so that the classical newsvendor's optimal order quantity is no longer optimal. Methods: We have developed an optimal order quantity model that enables us to incorporate the random yield of a product and the customer balking information such as a threshold inventory level of balking and the corresponding probability of a sale during the balking. Results: We illustrated the concepts developed here through simple numerical examples and showed the robustness of our model in a various setting of parameters. Conclusion: This paper provides a useful analysis showing that our distribution-specific and distribution-free approach to the optimal order quantity in the newsboy model can act as an effective tools to match supply with demand for these product lines.

• Korea-Australia Rheology Journal
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• 제12권2호
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• pp.107-117
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• 2000

Prediction of the product shape in sheet casting process is performed from the numerical simulation. A three-dimensional finite element method is used to investigate the flow behavior and to examine the effects of processing conditions on the sheet produced. Effects of inertia, gravity, surface tension and non-Newtonian viscosity on the thickness profile of the sheet are considered since the edge bead and the flow patterns in the chill roll region have great influence on the quality of the products. In the numerical simulation with free surface flows, the spine method is adopted to update the free surface, and the force-free boundary condition is imposed along the take-up plane to avoid severe singularity problems existing at the take-up plane. From the numerical results of steady isothermal flows of a generalized Newtonian fluid, it is shown that the draw ratio plays a major role in predicting the shape of the final sheet produced and the surface tension has considerable effect on the bead thickness ratio and the bead width fraction, while shear-thinning and/or tension-thickening viscosity affect the degree of neck-in.

• 한국식품영양과학회지
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• 제17권1호
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• pp.69-72
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• 1988

재래식, 개량식으로 만든 된장과 시판되는 된장의 맛성분중 유리아미노산과 핵산관련물질을 분석해 본 결과 지미성분으로 알려진 glutamic acid 함량은 개량메주로 담근 된장에서 월등히 많았고 총유리아미노산 함량도 역시 개량메주로 담근된장에 많은 것으로 나타났다. 세 가지 시료에서 핵산관련물질의 총함량은 시판된장이 가장 높았고, 지미성분으로 알려진 GMP의 양은 개량메주에서 제일 많았으며, 시판된장, 재래식메주 된장의 순서였다. 발효기간이 많이 경과된 상태의 된장에서는 ATP, ADP, AMP 의 함량이 낮게 나타났다.

• 한국식품영양과학회지
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• 제28권2호
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• pp.403-408
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• 1999

This study was conducted to investigate chemical properties, quality stability and utilization of approved sardine surimi(ASS) which is developed our laboratory. The product yield of the ASS was about 3 times higher than that of usual sardine surimi(SS). The proper addition concentration of sodium bicarbonate was 0.1% for the neutralization of the ASS. The content of salt soluble protein nitrogen in the ASS was about the half of that in the SS, while the content of water soluble protein nitrogen was 2.4 times higher in ASS. The total amount of free amino acids in the ASS was about 11 times higher than that of the SS. Predominant free amino acids in the ASS were histidine, taurine, glutamic acid and alanine, and those four amino acids occupied 94% of total amount of free amino acids. During cold storage at 21oC for 6 months, the quality of ASS was more stable than that of SS in judging from changes of water soluble and salt soluble protein nitrogen, AV and POV. Quality of fish burger, fish sausage and fried fish paste processed in accordance with commercial processing preparation using the ASS or SS exclusively and mixtures which other white meat fish surimi(alaska pollack, hair tail and sole) were proportionallly added to each of two types of sardine meat were evaluated. In case of fish burger, the product processed from the ASS only were superior.

• Mycobiology
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• 제47권2호
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• pp.217-229
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• 2019

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10-30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were $50^{\circ}C$ and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.

• 디지털융복합연구
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• 제18권8호
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• pp.1-9
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• 2020

본 연구에서는 중국 최대 온라인 리뷰 사이트인 Dazhong Dianping에서 중국인 관광객들은 한국과 중국 시내 면세점의 어떠한 속성들을 중요하게 생각하며 어떠한 Cluster들이 별점 점수(만족도)에 영향을 미치는지에 대해 알아보고자 하였다. 따라서 한국 시내면세점 리뷰 5,659개 중국 산야 시내면세점 리뷰 4,051개 총 9,710개를 R을 활용하여 텍스트 마이닝 분석하였다. 분석 결과, 한국 시내 면세점에서는 Sale, Membership, Food가 총 별점에 정(+)의 영향을 미치는 것으로 나타났다. 중국 시내면세점에서 Sale, Product, Airport, Food, Membership이 총 별점에 정(+)의 영향을 미치는 것으로 나타났다. 면세점 만족도 속성 중 Food라는 속성을 발견하면서 면세점 쇼핑 중 이용할 수 있는 식당 등의 편의 시설 공간을 제공하는 것이 중요함을 알 수 있었다. 이는 면세점 선택 및 만족의 새로운 속성을 찾았다는 점에 기인하여 연구를 확장시킬 수 있었다. 실무적으로 면세점 종사자들에게 식당 등의 편의시설 공간 제공이 중요함을 인식시킬 수 있었다.

• 한국식품과학회지
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• 제27권6호
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• pp.964-971
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• 1995

키조개 부산물로 부터 향미제로 응용하기 위하여 제조한 가수분해물의 유리아미노산 및 휘발성 향기성분을 분석한 결과, 유리아미노산의 경우 가수분해물이 생시료에 비해 3배 이상 증가하였으며 taurine의 함량이 가장 많았다. 그리고 생시료와 가수분해물의 휘발성 향기성분을 분석한 결과 총 109종의 화합물이 동정되었는데 이중에서 생시료는 88종, 가수분해물은 65종이 검출되었다. 그리고 이들은 주로 알데히드류(16종), 케톤류(17종), 알콜류(31종), 함질소화합물류(16종), 방향족화합물류(8종), 에스테르류(3종) 및 기타 화합물류(17종)으로 구성되어 있었다. 특히 생시료에서의 산화취 성분인 알데히드류 및 방향족화합물은 가수분해물에서 상당량 감소되었으며 반면에 고소한 향기성분인 heterocyclic 화합물이 상당량 검출되었다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2015년도 자성 및 자성재료 국제학술대회
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• pp.20-20
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• 2015