• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
• /
• pp.137-138
• /
• 2012

Domestic construction materials market was about 65 trillion won and it occupied 45% level of total construction cost by 2007. In addition, due to the recent rapid rise of crude oil and iron ore price, fluctuation of raw material cost has a great influence to the cost of construction industry. This means that smooth performance is closely related to construction materials. And among them, because of high putting rate of metal materials, it can be seen that the fluctuation of metal material prices is an important variables. So in this study, for the pre-study to analyze the impact of metallic material prices to construction cost, the researcher analyzed a causal relationship between metal material prices and construction cost.

• 산업경영시스템학회지
• /
• 제37권4호
• /
• pp.116-125
• /
• 2014

In this paper, we investigate an inventory and production system in a three-layer supply chain system involving a single supplier, single manufacturer and multiple retailers. Earlier study in this type of supply chain only consider a single raw material in order to produce single item, but we consider raw materials in order to produce multiple items. It is assumed that the cycle time at each stage is an integer multiple of the adjacent downstream stage. We develop an iterative solution procedure to find the order quantity for the multiple items and raw materials that minimizes the supply chain-wide total cost per unit time of the supplier and manufacturer's raw materials ordering and holding, setup and finished items holding, the retailer's ordering and inventory holding. Numerical examples are presented to show that the proposed heuristic gives good performance.

• Journal of Microbiology and Biotechnology
• /
• 제25권2호
• /
• pp.185-195
• /
• 2015

Glucoamylase is an important industrial enzyme. Glucoamylase production by industrial Aspergillus niger strain featured with two major problems: (i) empirical substrate feeding methods deteriorating the fermentation performance; and (ii) the high raw materials cost limiting the economics of the glucoamylase product with delegated specification. In this study, we first proposed a novel three-stage varied-rate substrate feeding strategy for efficient glucoamylase production in a 5 L bioreactor using the standard feeding medium, by comparing the changing patterns of the important physiological parameters such as DO, OUR, RQ, etc., when using different substrate feeding strategies. With this strategy, the glucoamylase activity and productivity reached higher levels of 11,000 U/ml and 84.6 U/ml/h, respectively. The performance enhancement in this case was beneficial from the following results: DO and OUR could be controlled at the higher levels (30%, 43.83 mmol/l/h), while RQ was maintained at a stable/lower level of 0.60 simultaneously throughout the fed-batch phase. Based on this three-stage varied-rate substrate feeding strategy, we further evaluated the economics of using alternative carbon sources, attempting to reduce the raw materials cost. The results revealed that cornstarch hydrolysate could be considered as the best carbon source to replace the standard and expensive feeding medium. In this case, the production cost of the glucoamylase with delegated specification (5,000 U/ml) could be saved by more than 61% while the product quality be ensured simultaneously. The proposed strategy showed application potential in improving the economics of industrial glucoamylase production.

• 품질경영학회지
• /
• 제16권1호
• /
• pp.78-87
• /
• 1988

The purpose of this study is to develop the algorithm applicable to the integrated production inventory model under quantity discount. To achieve this purpose, the integrated production inventory model which unifies the inventory problem of raw materials and the finished product for a single product manufacturing system is considered. The product is manufactured in batches and the raw materials are obtained from outside suppliers but some of the raw materials are discounted according to the purchasing quantity. The intergrated production inventory problem considered in this study is formulated by the non-linear mixed integer programming model, and the optimal solution is obtained by using the algorithm developed by Goyal. Then, the algorithm developed by this study is applied to the quantity discount problem, and the optimal solution is revised by this results. The quantity discount algorithm of the integrated production inventory model developed by this study gives a systematic procedure to obtain the optimum policy to minimize the total cost in any case. The numerical example involving 20 raw materials and 5 raw materials among them are discounted according to the purchasing quantity is given to verify the mathematical model and the algorithm developed in this study.

• 대한산업공학회지
• /
• 제11권2호
• /
• pp.29-37
• /
• 1985

This paper studies a production-inventory model which unifies the inventory problem of raw materials and the finished product for a single product manufacturing system. The integrated production-inventory model is formulated wth a nonlinear mixed integer programming problem. An algorithm is developed by utilizing the finite explicit enumeration method. The algorithm guarantees to generate an optimal policy for minimizing the total annual variable cost. A mumerical example involving 15 raw materials is given to illustrate the recommended solution procedure.

• 한국인터넷방송통신학회논문지
• /
• 제21권4호
• /
• pp.177-182
• /
• 2021

다양한 원재료를 혼합하여 원하는 성분 함유량을 가진 제품을 최소의 비용으로 생산하는 혼합 최적화 문제에 대해 일반적으로 O(n⁴)의 수행 복잡도의 선형계획법을 적용하고 있다. 본 논문에서는 이 문제에 대해 O(n log n)복잡도로 해를 얻을 수 있는 휴리스틱 알고리즘을 제안한다. 제안된 알고리즘은 합금 강판에서 요구하는 성분들의 함유량 범위를 충족시키면서 최소의 원자재비용을 얻기 위해, 원재료 단가 오름차순으로 성분별 함유량을 충족시키도록 원재료 양을 결정하였다. 3가지 사례에 대해 적용한 결과 제안된 알고리즘은 O(n log n)복잡도로 단순한 결정기법을 적용하였음에도 불구하고, LP의 최적화 기법과 동일하거나 보다 좋은 해를 얻을 수 있었다.

• 한국식품영양학회지
• /
• 제21권3호
• /
• pp.288-292
• /
• 2008

To save cost and time in Kimchi manufacture, the use of raw red-pepper paste and device-mashed vice materials, in place of dried red-pepper powder, was examined. Two kinds of Kimchi were prepared: One with dried red pepper powder and device-not mashed vice materials and the other with raw red pepper paste and device-mashed vice materials. Then pH, total acidity, total viable cell counts, total lactic acid bacteria and sensory characteristics were evaluated. Comparisons of the two Kimchis, indicated that changes in pH, total acidity, the total number of viable cells and total lactic acid bacteria were similar between the two groups. The acceptability score of the Kimchi made using the raw red pepper paste and device-mashed vice materials was slightly lower than that of Kimchi made using the dried red-pepper powder. This color was indistinctly changed since the vice materials were mashed and mixed. In conclusion, the results indicate that when manufacturing Kimchi using device-mashed vice materials, Kimchi of better quality can be made by adding dried red-pepper powder.

• 융합보안논문지
• /
• 제15권3_2호
• /
• pp.71-76
• /
• 2015

글로벌 기업들은 글로벌 생산 네트워크를 구축하여 세계 시장의 수요에 대응하고 있다. 그러나 해외 공장 설립 및 운영 시 현지 노동자들의 임금문제, 낮은 생산의욕 및 도난사고로 인한 피해가 속출하고 있다. 따라서 본 논문에서는 글로벌 기업의 해외 공장에서 원자재를 IP Camera와 RFID Box를 이용하여 관리함으로써, 실시간적인 재고 파악과 원자재의 도난 또는 멸실되는 상황을 방지할 수 있는 원자재 유실 방지 모델을 제안하였다. 이 모델은 원격지에 있는 재고의 관리가 가능하여 보다 비용 효율적인 생산관리를 실현할 수 있게 해주며, 불합격품 거래로 인한 브랜드 이미지 손실과 수익 저하를 방지할 수 있도록 해준다.

• 한국세라믹학회지
• /
• 제42권7호
• /
• pp.483-489
• /
• 2005

For the raw materials of 3CaO$\cdot$3Al$_{2}$O$_{3}$ $\cdot$CaSO$_{4}$(CSA) clinker manufacturing, the applications of industrial wastes such as waste shell, spent oil-refining catalyst and desulfurized gypsum were examined. The c1inkerbility of the raw mix and the behaviour of formation of clinker minerals were studied and then some hydraulic properties of cements containing the clinker were also investigated. By virtue of the high reactivity of thermally decomposed raw materials, CSA clinkers were obtained at relatively low temperature of 1250$^{\circ}C$ and thus oil-refining catalysts were more desirable than aluminium hydroxide as an aluminous raw material. The expansive cement samples showed somewhat lower flow value than that of OPC, but their compressive strengths were developed earlier and higher than that of OPC due to formation of ettringite in the early hydration time, which indicated the possibility of practical use of low-cost CSA clinker using industrial wastes only.

• 대한기계학회논문집A
• /
• 제26권4호
• /
• pp.660-666
• /
• 2002

It has many variables and factors to design the friction materials for automotive brake pads. The purpose of this study is to develop the proper method for design of low-cost and to know friction characteristics of each raw materials. For the purpose of examining the effect of each major raw materials, we used the Taguchi L9(3$^4$)orthogonal matrix and 1/5 scale dynamo machine for evaluation of the friction characteristics of composite brake pads. By adapting the Taguchi method, it is easy to investigate the influence of each component in complicated composites friction materials. After analyzing the testing results by the Taguchi method, the effect of factors and levels influenced friction behavior was studied.