• Korean Journal of Construction Engineering and Management
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• v.2 no.1 s.5
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• pp.98-106
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• 2001

The Ministry of Education and Human Resource Development has implemented the Construction Cost Saving Policy since 1998. The National Universities and Regional Education Committee have been required to follow the details of the Policy in constructing educational facilities in their jurisdiction. While the Policy has positive effect on construction cost saving of the entities, it has been criticized from the beginning of the Policy implementation because of its negative impact on project quality, education quality, trust in the public sector construction business, and solvent operation of the private construction companies which build the educational facilities in the entities. The research aims at investigating the pitfalls of the Policy and suggesting more reasonable approaches that can satisfy both the governmental entities and the private companies.

• The Journal of Information Systems
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• v.26 no.2
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• pp.143-164
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• 2017

Purpose The purpose of this study is to investigate to investigate the effects of cloud system on the efficiency improvement and cost-saving of production processes. It also tries to provide small- and medium-sized companies and IT practitioners with a practical guideline for a successful implementation of could systems. Design/methodology/approach This study was conducted by observing and analyzing a case of implementing a cloud system at a small-sized company having multiple job sites in terms of the improvement in data-sharing efficiency and cost-saving of production processes. Findings This study found that cloud system was an effective way of sharing data between and among production processes of geographically scattered job sites and thus, helped the company to remedy problems of work schedule and load-balance along sequential production processes. Cloud system also allowed the company to reduce the number of visits made by 3-inspectors to four job sites by 75% and the personnel cost related to inspectors' site visit.

• Journal of the military operations research society of Korea
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• v.26 no.1
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• pp.89-99
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• 2000

This paper deals with a heuristic algorithm for the vehicle routing-scheduling problem to minimize the total travel distance and the total cost. Because the aim of the Clarke-Wright method, one of famous heuristic methods, is to minimize the total travel distance of vehicles, it cannot consider the cost if the cost and the travel distance is not proportional. In the Clarke-Wright method, the route of each vehicle is found by using the saving matrix which is made by an assumption that the vehicle comes back to the starting point. The problem dealt with in the paper, however, does not need the vehicle to come back because each vehicle has its hoping-start-points and hoping-destination-points. Therefore we need a different saving matrix appropriate to this occasion. We propose a method to find an initial solution by applying network simplex method after transforming the vehicle routing-scheduling problem into the minimum cost problem. Moreover, we propose a method to minimize the total travel distance by using the modified saving matrix which is appropriate to no-return occasion and the method for the case of plural types of vehicles and freights.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.969-976
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• 2004

Building energy saving is one of the most important issues in these days. Energy saving control strategies should be developed properly to achieve the saving. One of such area we could apply is the HVAC (Heating, Ventilation and Air-Conditioning) system. Through the optimal control algorithm for building energy management system (EMS), you can not only save the cost of building energy, but also protect HVAC system components against the unexpected condition. In order to verify the effectiveness of building energy saving, field test was accomplished for several months at 'A' building. And to get the measured data, remote control was used. If the remote control is used in BAS (Building Automation System), control and monitoring can be done for all of the building systems, such as HVAC, power, lighting, security and fire-alarm etc. anywhere any time. Using the remote control, Control and monitoring is possible for the testing system without going there. As the results of field test, we could reduce $5{\sim}10\%$ of the building energy cost.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.151.1-151.1
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• 2010

Natural gas hydrates (NGH) provide 170 gas volumes per unit volume of the medium and are easier to make with moderate pressure and temperature (40 bar at 3 C). Once they form, their preservation temperature is 20 C at 1 bar, which is much milder than the LNG preservation. In case of using the NGH, The small and medium sized gas well has advantages for development because of NGH's these characteristics. According to the cost evaluation report of Gudmundsson in Norway and the research of MES in Japan, the gas well that uses the NGH has a cost saving effect about 10~20% compared LNG. The effect depends on distance and production. However, cost saving and efficiency of liquefaction process is increased by the development of LNG liquefaction technology. Therefore, these factors have to be reflected in economic analysis. The purpose of this research is to compare the cost of Gas Supply Chain according to the transport type, distance and gas reserves. Especially, we consider not only the cost of facility but also the total cost (production cost, transport cost, etc).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.10
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• pp.654-661
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• 2008

Our government will make a plan regulating the cooling limit temperature of the summer season to 26 degree and the heating limit temperature of the winter season to 20 degree for energy saving. Where, the key point of this politic pursuit can be the charge system on heating and cooling cost. Currently, the heating and cooling cost are charged as much as the volume or heat flow rate regardless of the high and low room temperature. However, we have suggested new cost estimating methodology as a worth method in the precedent study, and preformed the worth evaluation and cost allocation of electricity and heat on various cogenerations. In this study, we applied the suggested worth method to four kind of warm air, and preformed the worth evaluation and cost allocation of each warm air. As a result, the more energy a customer saved, the more heating unit cost decreased, and the more energy a customer consumed, the more heating unit cost increased. From this analysis, we hope that the suggested worth methodology can offer a theoretical basis to the politic pursuit of government, and induce the spontaneous energy saving of consumers.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.297-302
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• 1995

The experiment is conducted to reduce the labor and production cost with the labor save of harvest if cultivating the potatoes using the machine and the results are as follows. On labor saving effect in transparent vinyl mulching, digging working hours per 10a in the case of using tractor are 60 min., fixing + turning time is 5 min. and 30sec., the time of harvest is 65 min and 30sec., digging working hours using cultivator are 99 min. and fixing +turning time is 5 min. and 30sec., but the time of hand harvesting is 990 min. and in digging labor saving effect, tractor shows 94% in the harvesting period and harvest by cultivator 90%. On non mulching cases, the harvest by tractor takes 49 min. and 30 sec. and that by cultivator does 87 min. and 30 sec., and digging labor saving effect shows 94% in the tractor harvest and 90% in the cultivator harvest. Therefore, on the operation efficiency per hour, in the case of tractor with digger vinyl mulching and non mulching show, $0.091\sim0.121ha$ and in the case of cultivator with digger both show $0.057\sim0.069ha$, so in the mechanized harvest of potatoes, the harvest by tractor with digger is the best. On the cost and labor save for harvesting the potatoes with labor saving effect, tractor shows 19 hours and 20 min./10a in vinyl mulching and 19 hours. and 54 min./10a in non mulching, so it shows the short hours for harvesting. And labor saving effect shows $42\sim45%$ in comparison with 35 hours and 21 min. $\sim35$ hours and 23 min.($123,113\sim130,613$ won) of the hand harvest, so the cost was reduced to $71,250\sim72,225$ won. On the cultivator with diggers, vinyl mulching takes 19 hours and 55 min. and non mulching 19 hours and 38 min., so the labor saving effect and cost were reduced to $14\sim44%$ ($72,675\sim73,313$ won) in comparison with the hand harvest.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.97-103
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• 2012

Composite honeycomb sandwich plate is light and strong. It is easy to produce. It began to be applied to the bodyshell of rolling stock. Generally, weight saving amounts to 27%. However, the material cost of it is much higher than that of aluminum extrusion profile, which prevents popular use of it for bodyshell. In this paper, manufacturing processes of two light materials were compared to investigate cost impact. After cost breakdown was defined, economics of two materials was analyzed using the previous cost data. Easy production of composite bodyshell could compensate for higher material cost. Mass production of composite bodyshell can make the equipment cost lower for the composite bodyshell so that it may have strong competitiveness to the aluminum bodyshell. Operational energy saving due to weight reduction was also presented referring to the actual statistical data in a metro line.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.286-291
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• 2001

This paper describes an optimal scheduling for ice slurry systems for energy cost saving. The optimization technique applied in the study is the dynamic programming method, for which the state variable is the storage in the ice storage tank and the control variable is the state of chiller's on-off switching. Though the costs during charge period is included in optimization by taking the average cost of ice per hour for slurry making, the time horizon for the simulation is limited building cooling period because accurate charge rate from the ice maker into the ice storage tank cannot be estimated during the charge period. In the operating simulation after optimizing procedure, energy consumption and operating cost for the optimal control are calculated and compared with them for a conventional control with one case of cooling load profile.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.59-64
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• 2011

Feasibility study on energy saving system by utilizing exhausted heat from subway, which is one of the unused energy, was carried out. General heat source system using absorption chiller-heater was used for comparing to the energy saving system, and payback period method using initial cost and running cost of two systems, was used to perform economic estimation. Payback period was about ten years, and this period might be shortened if nation's economic support enact.