• 산업경영시스템학회지
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• 제39권4호
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• pp.7-14
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• 2016

Unlike most researches that focus on single manufacturer or single buyer, this research studies the cooperation policy for two participants of supply chain such as single vendor and single buyer. Especially, this paper deals with single vendor-single buyer integrated-production inventory problem. If the buyer orders products, then the vendor will start to make products and then the products will be shipped from the vendor to the buyer many times. The buyer is supposed to order again when the buyer's inventory level hits reorder point during the last shipment and this cycle keeps repeated. The buyer uses continuous review inventory policy and customer's demand is assumed to be probabilistic. The contribution of this paper is to present a mixed approach and derive its cost function. The existing policy assumes that the size of shipping batch from single vendor to single buyer is increasing, called Type 1, or constant, called Type 2. In mixed approach, the size of shipping batch is increasing at the beginning part of the cycle, and then its size is constant at the ending part of the cycle. The number of shipping for Type 1 and Type 2 in a cycle in mixed approach is determined to minimize total cost. The relationship between parameters, for example, the holding cost per product, the set up cost per order, and the shortage cost per item and decision variables such as order quantity, safety factor, the number of shipments, and shipment increasing factor is figured out via sensitivity analysis. Finally, it is statistically proved that the mixed approach is superior to the existing approaches.

• 한국식품영양학회지
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• 제26권3호
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• pp.358-365
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• 2013

The study was conducted to investigate the condition for mixed fermentation of Rhodilola sachalinensis with red ginseng using Lactobacillus acidophillus 128 and the changes of physicochemical properties and antioxidant activities before and after the lactic acid fermentation was examined. In the single fermentation of Rhodiola sachalinensis extract, the pH and titratable acidity rarely changed, and the number of lactic acid bacteria decreased greatly. On the other hand, in the lactic acid fermentation of Rhodiola sachalinensis-red ginseng mixed extract of 50% red ginseng content, the pH decreased, whereas the titratable acidity and the number of lactic acid bacteria increased. The solid content of optimal mixed extract for lactic acid fermentation was 0.5%. Sugar content decreased during fermentation, but total phenolic compounds tended to increase during fermentation. The salidroside and p-tyrosol content of the initial Rhodiola sachalinensis-red ginseng mixed extract was 419.5 mg% and 60.1 mg%, respectively; after fermentation, the salidroside content after lactic acid fermentation decreased greatly to 81.8 mg%, and the amount of p-tyrosol increased greatly to 324.9 mg%. The DPPH scavenging activity of Rhodiola sachalinensis-red ginseng mixed fermentate was 78.1% at 0.1% concentration, showing a tendency to increase as compared to 50.3% of Rhodiola sachalinensis-red ginseng mixed extract before the fermentation (p<0.05); it was a higher antioxidant activity as compared to the single fermentation of Rhodiola sachalinensis or red ginseng.

• 대한화학회지
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• 제59권4호
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• pp.271-279
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• 2015

음이온성 계면활성제인 sodium dodecanoate과 sodium n-octanoate의 혼합미셀 물성인 임계미셀농도(CMC), 반대이온의 결합상수(B), 및 미셀형성 응집수(N^*) 등을 여러 조성에서 전기전도도법과 광산란법으로 조사하였다. 여러 혼합조성에서의 혼합미셀 형성에 대한 실험 결과는 이상용액의 예측 거동과는 상당히 벗어났으므로, 정규용액 이론에 기반을 둔 Rubingh 모델과 Motomura 모델을 이용하여 분석하였다. 또 미셀 형성에 대한 표준 Gibbs 에너지 ΔG^micel,0는 전체 조성에서 음의 값이 얻어져 혼합미셀의 안정성을 확인할 수 있었으며, 이러한 ΔG^micel,0 측정값은 이론적 계산치와 실험 오차 내에서 일치하였다.

• Journal of Mechanical Science and Technology
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• 제19권3호
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• pp.913-923
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• 2005

The dynamic mixed model (DMM) combined with a box filter of Zang et. al. (1993) has been generalized for passive scalar transport and applied to large eddy simulation of turbulent channel flows with Prandtl number up to 10. Results from a priori test showed that DMM is capable of predicting both subgrid-scale (SGS) scalar flux and dissipation rather accurately for the Prandtl numbers considered. This would suggest that the favorable feature of DMM, originally developed for the velocity field, works equally well for scalar transport problem. The validity of the DMM has also been tested a posteriori. The results of the large eddy simulation showed that DMM is superior to the dynamic Smagorinsky model in the prediction of scalar field and the model performance of DMM depends to a lesser degree on the ratio of test to grid filter widths, unlike in the a priori test.

• 설비공학논문집
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• 제7권3호
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• pp.461-472
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• 1995

The interaction of laminar mixed convection and surface radiation in a two-dimensional channel with an array of rectangular blocks is analyzed numerically. Three blocks are maintained at high temperature and the other bottom and top horizontal walls are insulated. Discrete ordinate method(DOM) is introduced to analyze the radiative heat transfer. The effects of the variations of Reynolds number and channel specifications on the heat transfer characteristics are investigated. The average Nusselt numbers along the block surfaces are correlated and presented in terms of Reynolds number and dimensionless geometric parameters such as the block spacing, height and channel spacing. For the conditions considered in this study, average Nusselt numbers along the block surfaces are strongly influenced by the channel spacing and Reynolds number but weakly influenced by the block spacing and block height.

• 설비공학논문집
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• 제13권12호
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• pp.1230-1235
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• 2001

The laminar convection heat transfer in a ventilated space with various horizontal partitions was studied numerically and experimentally. The experimental results by holographic interferometer showed good agreements with the numerical results. For the numerical study, the governing equations were solved by using a finite volume method for $46.6\leqRe\leq1332,\;1460\leqGr\leql1585$, Pr=0.71 and the variations of partition lengths. The isotherms and velocity vectors have been represented for various parameters. As the length of partition increases, the convection heat transfer decreases. Based on the numerical data, a correlation was obtained for the dimensionless mean Nusselt number in terms of $Gr/Re^2$. In the region of $Gr/Re^2$<1, the mean Nusselt number was very small, but in the region of $Gr/Re^2\geq1$, the mean Nusselt number was constant.

• 한국실내디자인학회논문집
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• 제25권1호
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• pp.151-162
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• 2016

Various mixed-use buildings have been developed in the process of resolving the issue of 'urban regeneration' in the modern city. In this urban regeneration process, the size of the mixed-use buildings and the level of their functional complexity have been increased. It requires a quantitative and systematic approach in order to analyze the internal circulation flow within the large-scale commercial mixed-use buildings. Circulation system and environmental factors, respectively, have been vital criteria for the effectiveness of a Wayfinding design within the mixed-use buildings. The circulation system in this paper consists of 1) the number of the incoming paths at each node, and 2) the angle of directional transition from the incoming paths at the node. The environmental factors include 1) color tone, 2) materials, 3) lighting, and 4) pattern of the interior design of the mixed-use buildings. In this paper, the author develops a method of investigating the influence of the correlation between the circulation system and the environmental factors on the design of Wayfinding on the view of the remodeled COEX MALL interior design.

• 한국응용과학기술학회지
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• 제27권2호
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• pp.123-128
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• 2010

The continuous transesterification of mixed fat was done on the plug flow reactor packed with the static mixers. The transesterification using 0.5 wt% KOH, 0.8 wt% TMAH and mixed catalyst[40 v/v% KOH(0.5 wt%)+60 v/v% TMAH(0.8 wt%)] was conducted with the changes of molar ratios, weight percentage of beef, flow rates and number of static mixer's elements at $65^{\circ}C$. The overall conversion of mixed fat at 1:8 molar ratio, 50 wt% of beef and 24 of static mixer's elements increased until 0.7mL/min of flow rate. The overall conversion of mixed fat showed 96% at those conditions. So, the optimum operating conditions on tublar reactor were 1:8 molar ratio, 50 wt% of beef, 0.7 mL/min of flow rate and 24 of static mixer' s elements.

• 한국환경복원기술학회지
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• 제1권1호
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• pp.102-109
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• 1998

This study was conducted to find out the growth characteristic of mixed-seeding in the grasses for slope revegetation measures. Seeding treatment with six combination types of five grasses used for this experiment such as orchardgrass(Dactylis glomerata 'Potomac'), perennial ryegrass(Lolium perenne 'Manhattan'), tall fescue(Festuca arundinacea 'Jaguar'), kentucky bluegrass(Poa pratensis 'Majestic') and weeping lovegrass(Eragrostis curvula). The growth of orchardgrass, perennial ryegrass and tall fescue were good on mixed-seeding condition in case of number of individuals, heights and coverages at this experiment. These plants will useful for revegetation measures mixed-seeding, but weeping love grass and kentucky bluegrass did not show a desirable growth in mixed-seeding condition, and these plant prefered mixed seeding to single seeding. Regeneration percents of orchardgrass, perennial ryegrass and tall fescue were higher than that of weeping love grass and kentucky bluegrass, and coverage kept on good condition through one year after seeding, therefore, these plants will effective for initial stage revegetation measures.

• 한국환경생태학회지
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• 제9권2호
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• pp.197-201
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• 1996

빈도측정을 고려한 삼림군집구조 조사시 관목층의 적정 조사구수를 결정하기 위하여 오대산국립공원지역 젓나무-활엽수 혼효림군집의 관목층을 대상으로 30개의 5m*5m 조사구를 설치한 후 종수-면적 곡선, performance curve 등을 적용하였다. 종수-면적 곡선에 있어서 누적조사구수의 증가율보다 출현종수의 증가율이 낮은 최소 조사구수는 6개였으며, 누적조사구수의 증가율에 비하여 출현종수의 증가율이 1/2 이하인 최소 조사구수는 11개이었다. 주요 수종의 중요치에 의한 performance curve를 작성한 결과 우점종과 준우점종의 구분이 뚜렷해지는 최소 조사구수는 5개이었으며, 준우점종 중 제 1의 준우점종이 구분되는 최소 조사구수는 10개이었다. 본 조사지를 대표한다고 할 수 있는 전체 조사구수 30개와 비교할 때, 종다양도는 조사구수 5개 이상에서 0.05 이하의 차이를 보였으며, 유사도지수는 조사구수 5개 이상에서 70% 이상, 10개 이상에서 80% 이상의 값을 보였다. 이상의 결과를 종합하면 본 조사지인 젓나무-활엽수 혼효림군집 관목층의 무작위표본추출법에 의한 5m*5m 크기의 적정조사구수는 일반적인 경우 대체로 5개, 보다 정확성을 요구할 경우 대체로 10개이었다.