• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.4
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• pp.51-58
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• 2008

Unit costs for energy production in bioenergy facilities are dependent upon both fixed cost for facility construction and operational costs including biomass feedstock supply. With the increase of capacity, unit fixed cost could be decreased while supply cost tends to increase due to the longer transportation distance. It is desirable to take into account biomass availability in planning bioenergy facilities. A cumulative curve relationship was proposed to relate biomass availability and cumulative products of biomass amount and transportation distance. Optimum size of gasification facilities was affected by collection cost, biomass cumulative relationship. Based on biomass availability of Icheon-City, optimum sizes were about $400kW_{th}$ for gas production, and about $200kW_{el}$ for power generation. Unit cost of bioenergy production could be substantially reduced by reducing collection cost through supplying biomass from diverse sources including land development areas where significant amount of waste wood is generated. When planning bioenergy facilities, however, biomass availability and spatial distribution are key factors in determining the size of capacity.

• Journal of Biosystems Engineering
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• v.19 no.4
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• pp.329-342
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• 1994

In order to reduce the production cost and improve the quality of dairy feed, several dairy feed mill models suitable for Korean farm size were developed. 6 TMR models were developed for the 1000, 600, 200 head of dairy cattle, and evaluated for capital investments and production costs to suggest the best model. Followings are summary of this study : 1. TMR terminal models were designed that dairy production capacity of TMR1000 models are 40 ton/day, TMR600 model is 20 ton/day and TMR200 models are 10 ton/day. Also, they can be extended their capacity up to twice. 2. Capital investment of TMR terminal models is 145 million won for TMR200-1,205 million won for TMR600 and 609 million won for TMR1000-3 model. 3. The bigger TMR terminal model has the more advantage in production cost. The best model for 1000 head of dairy cattle farm was TMR1000-3 with 10,849 won/ton of production cost, TMR600 for 600 head of dairy cattle farm with 13,829 won/ton, TMR200-1 for 200 head of dairy cattle farm with 16,943 won/ton of production cost, so feed production cost for the 200 head farm was 50% higher than 1,000 head size farm.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.173-185
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• 2004

The production using U-shaped line is studied. This research presents the relationship among machining time, cycle time and production rate in a U-shaped line. The U-shaped line produces shafts by automated machines. In this paper when any production rate is given the U-shaped line always satisfies the production rate. An algorithm is developed for the determination of cycle time, the number of machines and workers of the U-shaped line in order to minimize the total machine capacity and the number of workers for any given production rate. The U-shaped line was successfully designed by applying the proposed algorithm.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.71-79
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• 1993

Dynamic production planning problems are to determine the optimal production times and production quantities of product for discrete finite periods. In previous many researches, the solutions for these problems have been developed through the algorithms using dynamic programming. The purpose of this research is to suggest the new algorithm using linear programming. This research is to determine optimal production quantities of product in each period to satisfy dynamic for discrete finite periods, minimizing the total of production cost and inventory holding cost. Cost functions are concave, and no backlogging for product is allowed. The new algorithm for capacity constrained problem is developed.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.209-214
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• 2018

In this paper, the techno-economic analysis of glycerol steam reforming for $H_2$ production capacity of $300m^3\;h^{-1}$ was carried out. The process of glycerol steam reforming was constructed by using Aspen $HYSYS^{(R)}$, a commercial process simulator, and parametric studies for the effect of the operating temperature on $H_2$ production was performed. Moreover, the economic analysis was conducted through an itemized cost estimation, sensitivity analysis (SA) and cash flow diagram (CFD), and the unit $H_2$ production cost was 5.10 $ ${kgH_2}^{-1}$ through the itemized cost estimation of glycerol steam reforming for $H_2$ production capacity of $300m^3\;h^{-1}$. SA was employed to identify key economic factors and various economic indicators such as net present value (NPV), discounted payback period (DPBP), and present value ratio (PVR) were found according to $H_2$ selling price using CFD.

• IE interfaces
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• v.10 no.1
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• pp.15-22
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• 1997

In semiconductor manufacturing, the probe process between fabrication and assembly process is constrained mostly by the equipment capacity because most products pass through the similar procedures. The probe process is usually performed in a batch mode with relatively short cycle times. The capability of the probe process can be determined by the optimal combination of the equipments and the products. A probe line usually has several types of equipment with different capacity. In this study, the probe line is modeled in terms of capacity to give the efficient planning and control procedure. For the practical usage, the hierarchical capacity planning procedure is used. First, a monthly capacity plan is made to meet the monthly production plan of each product. Secondly, the daily capacity planning is performed by considering the monthly capacity plan and the daily fabrication output. Simple heuristic algorithms for daily capacity planning are developed and some experimental results are shown.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.99-105
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• 1969

The results of investigation and management analysis for the silk filatures in Korea until 1968 are evaluated as followings. (1) The average cocoon purchasing amount for a filature was found as 10,800kg and they are processed 105kg per man on the cocoon assorting process, 8,683kg per day during the drying process of which 42 percent are dried with low temperature drying system. (2) The average cocoon cooking capacity is 50 g, cocoon per minute, but the cooking capacity per man is smaller in case of larger factory. (3) The silk production capacity per month per a filature is 6,000kg and the amount gets smaller in case of larger factory. (4) The employee cost per one kg of raw silk production was found as high in smaller factory and it was found that 200~300 sets size was the optimum capacity for operation. (5) In case of multiends silk reeling machine, the employee cost for the silk reeling process acts as the most peculier factor among six different cocoon processes and it is reached to conclued to deduct the number of employees for this process in order to deduct the production cost. (6) The correlation coefficients between cost factors and total labour cost was found as 46 percent, therefore the rest (54％) will be the production cost other than labour cost.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.21-29
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• 2010

The concept of carrying capacity for bivalve culture of an area can be classified into four hierarchical categories, according to their level of complexity and scope, such as physical, production, ecological and social carrying capacity. Most scientific efforts to date have been directed towards modelling production carrying capacity and some of the resultant models have been used successfully. But, the modelling of ecological carrying capacity is still in its infancy, because it should consider the whole ecosystem and all culture activities. A more holistic approach is needed to determine the influence of bivalve aquaculture on the environment and ecological carrying capacity. As an alternative, we can use a set of ecological indicators which can show the environmental performance of bivalve farms and assess ecological carrying capacity. Clearance efficiency and filtration pressure indicators show the value of 0.331 and 0.203, respectively, and these indicators suggest that the present level of culture in GeojeHansan Bay is above the ecological carrying capacity of 0.05. Consequently, these indicators can provide a guidance on the present level of culture in regard to production and ecological carrying capacity in GeojeHansan Bay.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.82-83
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• 2017

The samll-medium sized cities do not have enough infrastructure for the construction work, especially in terms of concrete supply. This research surveyed the capacity of remicon companies in Gunsan related with production and delivery. Their production capacity is bigger than the daily quantity required, however the delivery capacity is not enough to supply the daily quantity required and it is inevitable to use the several remicon using different admixture. It might cause the harm to the structure. This research studied the way to remove the quality risk when using different admixture at the same time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.6
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• pp.1-6
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• 1982

The objective of this thesis to Provide a better insight into the effect of the amount of in-process storage has on the efficiency of production line with variable operation times. It is assumed that the material enters the line at the first work station and is then processed progressively through the line until it exits at the last work station, a finite amount of in-process storage is provided before all but the first work station of the line and the operation time of the work stations are statistically independent and follow exponential distribution. Under the above assumption, optimum allocation model is developed and following two approaches are used : 1) Given the available storage capacity, optimum allocation which minimizes the number of items in the line. 2) Given the available storage capacity, optimum allocation which. maximizes the utilization factor of the line. In a balanced three stage line, the production line efficiency is maximized under both categories when the second in-process storage is larger than the first.