• 대한산업공학회지
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• 제4권2호
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• pp.97-105
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• 1978

A mathematical model is developed in order to describe the network configuration and heating distribution to a Central District Heating System for an Urban Residential Community. The purpose of using this model is to optimize operating costs and to distribute heat to the Residential Community efficiently. In particular, because of the inherent nonlinearity and dual optimization of the problem a dyamic programming approach is taken. It is turned out that the optimal cost of the system is a strong non-linear function of the network. In particular, it is found that increasing N, the number of houses, may not necessarily imply increased costs. It is felt that past failure of producing economical systems may be due to the improper attention given to the network.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.78-84
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• 2005

The development of eco-friendly low pressure carburizing system with high pressure gas quenching (LPC_GQ, 500kg/charge) led to new stage in the fundamental case-hardening treatments. This is due to its ability to provide tighter tolerances on the carburizing process with notable reductions in distortion of the carburized and hardened workpiece. This system is characteristics by high uniformity and reproducibility of heat treatment results, absence of an intergranular oxidation layer, carburizing of complex shapes, reduced cycle time, low operating costs, simplified production, eliminate post washing, and reduced grinding costs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.264-265
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• 2006

This paper presents direct load control algorithm based locational and electric load characteristics. Direct load control is defined that demand-side management program activities that can interrupt consumer load at the time of annual peak load by direct control of the utility system operator by interruption power supply to individual appliances or equipment on consumer premises. Korean power system is divided into 14-areas considering branches operating in KEPCO, and electric loads are classified into 19 load groups considering interruption costs in this paper. The purpose of proposed method is to decrease social losses by controlling electric loads mainly whose interruption costs are low. It is expected that the proposed algorithm can be used as the countermeasure for the emergency state of the electric power dispatch in a operation point of view.

• 한국기계가공학회지
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• 제14권1호
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• pp.105-110
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• 2015

In this study, a high-speed procedure to be used in composite molding technology is developed for the production of a hybrid supercapacitor in a progressive and revolutionary current in a production system, as are the related operating conditions. Mold parts with solid modeling, the ease of programming of future mold product designs, tolerance management, and pre-explode tests by the building of a progressive die design system using Cimatron_E10 Die Design Software for the strip layout are done. The capacity of the super-hybrid composite mold design will save time and money through its verification of the manufacture of molds. We plan to apply this to future related products for production cost savings of more than 30% achieved by considering the components of the production costs, labor, and material costs of production as compared to conventional production methods.

• International journal of advanced smart convergence
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• 제1권2호
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• pp.12-15
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• 2012

Energy costs for operating and cooling computing resources in Cloud infrastructure have increased significantly up to the point where they would surpass the hardware purchasing costs. Thus, reducing the energy consumption can save a significant amount of management cost. One of major approach is removing hardware over-provisioning. In this paper, we propose a technique that facilitates power saving through reducing resource over provisioning based on virtualization technology. To this end, we use dynamic workload shaping to reschedule and redistribute job requests considering overall power consumption. In this paper, we present our approach to shape workloads dynamically and distribute them on virtual machines and physical machines through virtualization technology. We generated synthetic workload data and evaluated it in simulating and real implementation. Our simulated results demonstrate our approach outperforms to when not using no workload shaping methodology.

• 무역상무연구
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• 제14권
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• pp.219-233
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• 2000

Korea has been faced a difficult situation with regard to the cost of physical distribution(PD). The problem have arisen from the fact that Korean firms have far different cost structures of the PD according to its industry or business. High PD costs sometimes reduce firms' operating income and perceived competitive disadvantages not only in domestic but in world-wide business. In this research, we examine the factors affecting firm's PD cost by investigating financial and non-financial variables such as variable cost to sales ratio and number of employee of a firm. Analyses are performed to construct research models with t-test and the logistic regression estimation.

• 열처리공학회지
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• 제19권5호
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• pp.262-269
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• 2006

The development of eco-friendly low pressure carburizing system with high pressure gas quenching(LPC-GQ, 500kg/charge) led to new stage in the fundamental case-hardening treatments. This is due to its ability to provide tighter tolerances on the carburizing process with notable reductions in distortion of the carburized and hardened workpiece. This system is characteristics by high uniformity and reproducibility of heat treatment results, absence of an intergranular oxidation layer, carburizing of complex shapes, reduced cycle time, low operating costs, simplified production, eliminate post washing, and reduced grinding costs.

• 한국항만경제학회지
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• 제22권2호
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• pp.109-133
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• 2006

The Study investigated economic effects and the conditions in the public Shipping e-marketplace. For efficient operation of the public Shipping e-marketplace, this study analyzed how do the participation and community actualize in the public Shipping e-marketplace actualize. According to the research results of the Shipping Cooperations, For Promoting participation in the public Shipping e-marketplace, the Cyber-intermediary operating public Shipping e-marketplace provides timely shipping information, needs publicity strategy generating more benefits than offline transaction, and gives a conviction of the searching costs and transaction costs decrease. Second For promoting community, the Cyber-intermediary must playa major role in electronic community and drive forward continuous publicity strategy in the public Shipping e-marketplace.

• 자원ㆍ환경경제연구
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• 제11권4호
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• pp.633-657
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• 2002

This study presents a demand modelling for landfill gas, which is used as alternative energy source for district cooling business. By analyzing the cost minimizing behavior of producer facing with three alternative energy sources such as electricity, cooling heat water, and gas, a demand function for landfill gas is derived from the optimal operating time of gas fired production facility, and estimated using unpublished data, which are associated with Seoul city's development plan for Sang-am area. The estimation results repeals that Seoul City could supply the land-fill gas of 13.76 million cubic meters each year at the price of about 16 won per cubic meters. However, if the investment costs associated with installation of gas collecting facilities are treated as sunk costs, annual amount of gas supplied is expected to increase to 14.22 million cubic meters at a lower unit price of 14.76 won.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.105-106
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• 2006

It is important to identify the exact target optical cable that a worker look for when he executes a cable construction work. Until now, An Optical cable identification work has been done by a manual pulling of an optical cable or by the method of using RF signals. But these methods not only consume much time and labor costs but also have a distance limit of the optical cable to identify. In this paper, we propose a method that uses the phase change signal of the optical interferometer to identify an optical cable. With the proposed method the field worker can have an efficient tool to prevent miscutting the optical cable and can also save operating costs.