• 산업경영시스템학회지
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• 제16권28호
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• pp.203-209
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• 1993

In Factory Automation environments such as FMS, the formation of machine-part based on GT should be considered. The purpose of this study is to develop a economic heuristic algorithm which considers various elements such as unit processing time, subcontract cost, and functional operation cost, machine processing capacity etc. When this proposed approach is applied to the real situation expected benefits are as follows: the reduction of production lead time work in process, labor force, tooling, rework and scrap, setup time, order time delivery, and paper work, etc.

• 산업경영시스템학회지
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• 제35권4호
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• pp.16-23
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• 2012

At present, the significance of a new manufacturing system that can shift from 'mass production' and consider life cycles of a product is pointed out and extremely expected. In such a situation, it is recognized that the modular design, often called 'unit design,' is the important design methodology which realizes the new production system enabling 'cost reduction,' 'flexible production of a multi-functional artifact,' 'settlement of an environmental issue,' and so on. A module (unit) of a product is generally defined as 'the parts group made into the sub-system from a certain specific viewpoint.' So far, there have been many researches related to the modular design. However, they are often limited to a certain viewpoint (objective). This paper proposes a simple but effective method for multi-objective modular design. In the proposed method, a new design metric, called similarity index, is proposed to evaluate the modular design candidates from the multiple viewpoints.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.854-866
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• 2016

The production cost of biodiesel from microalgae is still not competitive, compared with that of petroleum fuels. The genetic improvement of microalgal strains to increase triacylglycerol (TAG) accumulation is one way to reduce production costs. One of the most promising approaches is the isolation of starch-deficient mutants, which have been reported to successfully increase TAG yields. To date, such a stable mutant is not available in an oleaginous marine microalga, despite several advantages of using marine species for biodiesel production. Algae in the genus Dunaliella are known to tolerate high salt concentration and other environmental stresses. In addition, the cultivation processes for large-scale outdoor commercialization have been well established for this genus. In this study, Dunaliella tertiolecta was used to screen for starch-deficient mutants, using an iodine vapor-staining method. Four out of 20,016 UV-mutagenized strains showed a substantial reduction of starch content. A significantly higher TAG content, up to 3-fold of the wild-type level, was observed in three of the mutants upon induction by nitrogen depletion. The carotenoid production and growth characteristics of these mutants, under both normal and oxidative stress conditions, were not compromised, suggesting that these processes are not necessarily affected by starch deficiency. The results from this work open up new possibilities for exploring Dunaliella for biodiesel production.

• 산업경영시스템학회지
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• 제4권5호
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• pp.1-10
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• 1981

The purpose of this study is to cut down cost of production and improve the productivity of industry through quality improvement of castings and reduction of defectives by applying the experimental design to the foundry sand mixing operation done at molding department in the foundry. Among the related foundry sand mixing factors which have an effect on casting the experiment of which factors have a dominant effect on quality improvement was performed between two different levels by means of "$2^n$ type orthogonal array." The results cail be summarized as follows ; (1) The optimum conditions per each foundry sand mixing between two different levels proved to be such as $A_2$(used sand) : 24 unit (172.8kg), $B_2$(unused sand ) : 2 unit (15.0kg), $C_2$(binder) : 2.5 unit (4.4kg). $D_2$(addition agent) : 1 unit(1.4kg) and $F_1$(moisture) : 7.4%(14.6kg). (2) As a result of the application of experimental design, the fraction defective during the foundry sand mixing operation turned out to be reduced front 6.6% to 2.04%. (3) For the purpose of cost-down, It was found that the optimum level decision of foundry sand mixing for various castings is required to be made by means of experimental design.al design.

• Asian-Australasian Journal of Animal Sciences
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• 제13권12호
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• pp.1726-1730
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• 2000

High fibre (CF, 242 g/kg) sunflower seed meal (SSM) was incorporated in standard grower and layer quail diets at 0, 50, 75 or 100 g/kg replacing part of the soybean meal (SBM) and deoiled rice bran (DORB). Each grower diet was offered to 30 quails housed in battery cages from day one to 5 weeks of age. At the end of the growing period, Twelve female quails from each of the four respective dietary groups were transferred to the individual laying cages and their laying performance from 7 to 20 weeks of age were evaluated on diets containing SSM at similar levels as that during the growing period. The results of growth bioassay revealed that the live weight gain, feed intake, nutrient retention and carcass characteristics of quails in different dietary groups did not vary significantly (p>0.05), although the quails fed SSM based diets utilized the feed less (p<0.05) efficiently than those fed the control diet. During the laying period, the egg production and egg quality traits remained unaffected due to dietary treatments but feed required per unit egg production increased (p<0.05) as the level of SSM in diet was increased to 100 g/kg. Although, the cost of feed per kg decreased due to the incorporation of SSM in diet but the same was not reflected in feed cost per unit gain, meat or egg production as such parameters were comparable on all the diets. It could thus be concluded that the SSM can be incorporated in quail diets upto 100 g/kg for part of SBM, an item usually expensive and also in short supply in developing countries including India.

• 산업공학
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• 제16권1호
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• pp.27-33
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• 2003

The maintenance cost in K Steelworks has been continuously increased in proportion to the production cost. However, there seems to be a possibility of reducing cost through the optimization of maintenance actions. The failure types of the equipment in steelworks ate various with different failure cost. Thus the failure rate and cost of each type of failures should be considered simultaneously when the optimum maintenance period is to be determined. It is considered that the equipment undergoes periodic replacement and a specified number of incomplete preventive maintenance actions are performed during a replacement period. Assuming that the time to failure follows a Weibull distribution, the parameters of the failure rate are estimated using the maximum likelihood estimation. The optimal replacement period is determined to minimize the average cost per unit time. As the result of analysis it is suggested that the existing maintenance period for a hot-rolling equipment can be extended significantly.

• 대한환경공학회지
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• 제39권4호
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• pp.169-179
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• 2017

기후변화를 대비하여 국내 수자원 확보를 위한 해수담수화 플랜트의 필요성이 점차 높아지고 있어 향후 해수담수화 플랜트 건설시 경제적 판단의 근간이 될 수 있는 자료의 필요성도 또한 높아졌다. 이에 본 연구에서는 국내 해수담수화 플랜트 설치가 가능한 지역, 인천, 대산, 여수, 부산, 울산, 속초시를 대상으로 생산수 단가를 추정하여, 향후 플랜트 건설시 참고 자료로 활용이 가능하도록 제안하고자 하였다. 동해바다를 취수원으로 하는 속초와 울산시 생산수 단가는 부산과 여수시의 단가와 유사하였으나, 서해바다를 취수원으로 하는 인천과 대산에 비해 취수시설 건설비용 저감으로 인하여 비교적 경제적인 생산수 단가 범위를 나타내었다. 염도 조건은 비교적 유사하여 생산수 단가에 큰 영향을 미치지 못하는 것으로 사료되나, 계절별 수온 차에 의한 영향은 역삼투막의 생산수량 차이에 의해 높게 나타날 것으로 사료되었다. 가장 크게 생산수 단가에 영향을 미치는 요소는 생애주기 분석 시 적용되는 감가상각 연수와 플랜트 용량이었으며, 인천과 대산의 경우 감가상각 연수에 따라 최대 29%, 플랜트 용량에 따라 22%까지 차이가 발생하였다. 그러나 본 연구에서 추정된 생산수 단가는 간접비 등을 고려하지 않은 것으로 국내에서 생산할 수 있는 최소한의 단가로 고려되었으며, 실질적인 공사 시에는 제시된 생산수 단가보다 증가될 것으로 사료된다.

• Nuclear Engineering and Technology
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• 제9권3호
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• pp.151-163
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• 1977

CANDU-PHWR형 원자로인 월성 1호기의 Zircaloy-4 피복 핵연료 설계치를 중심으로 Segel method에 의하며 FACOM 230 OS$_2$/VS 콤퓨터 시스템을 사용하여 핵연료비를 계산하였다. 아울러 핵연료 제조공장의 수덩, 가동을, 곧장시설 낑산규모 증대, 건설지 및 운전비기 변동, 이자율의 변화, 원광가격의 물가상승을, 기술개발인자 등이 핵연료비 계산에 미치는 효과에 패한 민감도를 분석하였다.

• 대한산업공학회지
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• 제31권3호
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• pp.248-256
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• 2005

In this paper, we compare two EOQ based inventory models under total cost minimization and profit maximization to investigate the difference in the optimal solutions. First of all, optimal solutions for both models through geometric programming (GP) techniques are found considering production (lot sizing) as well as marketing (pricing) decisions. An investigation of the effects of the changes in the optimal solutions according to varied parameters is performed by studying optimality conditions as well as by performing numerical analysis. We then conduct comparative analysis between the models to show the relationships between the optimal solutions of the models where certain conditions in the cost per unit and the demand per unit time are given. Several interesting economic implications and managerial insights are observed from this analysis.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2004년도 정기학술대회
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• pp.201-206
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• 2004

The linear consecutive-k-out-of-n:F system consists of n components ordered linearly and fails if and only if at least k consecutive components fail. We assume that the failure times of components are independent and identical exponentially distributed. This paper develops a model to calculate the expected cost per unit time of a linear consecutive-k-out-of-n:F system. The optimization problem to find the system structure parameter k to minimize the expected cost per unit time is considered.