• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.208-213
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• 2015

This study presents the estimation method for the optimal capacity of BESS(Battery Energy Storage System) in order to reduce the electric charges of common consumer. The daily optimal charge and discharge plan of BESS which satisfies the given constraints is established using linear programming through the change of rated output/rated capacity of the time that shows the electric charges in the highest reduced rate has been selected. There will be a problem to compare only reduced rate because the bigger the rated capacity, the more reduced rate is increased. Therefore, rated output/rated capacity of the time when the reduced amount of electric charges for a year is higher than the investment cost of BESS was selected.

• Journal of Korean Society for Quality Management
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• v.31 no.4
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• pp.1-18
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• 2003

Quality is a critical competitive factor in today's environment because of the impact of quality on costs and delivery. Many companies regard quality as a key concept of company strategy in order to achieve the competitive edge. Measuring and reporting quality cost is the first step in quality management program. The supposition of quality cost model is that investment in prevention activities will bring rewards from reduced failure costs, and that further investment in prevention activities will show profits from reduced appraisal costs. In this study, the degree of quality cost deviation is conceptualized. This means a deviation between the ideal and present ranking in the amounts of quality cost categories. This study analysed that the effect of its deviation on quality management activity and performance variables. However, there are no difference in these variables. The major reason is that most of companies are endeavoring for quality management but operating quality cost system unsystematically. The review against a prevention and appraisal activity is necessary.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.101-102
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• 2017

This study was carried out as basic study to apply to construction site the HPC method which is being developed. The construction cost of HPC method was analyzed in comparison with conventional method (half slab method). With regard to research method, it was decided that data on construction work carried out by half slab method was analyzed. According to the results of study, in case of being applied to the construction work using a divided column, the number of columns was decreased. So, it was shown that member production cost, and transport and assemblage cost reduced. In case of being applied to construction work using an undivided column, the analysis showed that there was little difference in construction cost. Therefore, the analysis showed that, if HPC construction method was applied to large structure using a large column, the construction cost was reduced to some extent in comparison with conventional half slab method.

• Management & Information Systems Review
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• v.5
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• pp.287-300
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• 2000

Project Managers want to reduce the cost and the completion time of the project simultaneously. But the project completion time tends to increase as the project cost is reduced, and the project cost has a tendency to increase as the project completion time is reduced. In this paper, the resource constrained project scheduling problem with multiple crashable modes is considered. An exact solution method for finding the efficient solution set and the computational results are introduced.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.245-248
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• 2010

This study was conducted to investigate effect of changes in target fat and protein contents in milk on feed cost using a simulation modeling approach based on the 2001 dairy NRC. Two simulations were done; simulation I had a limitation (up to 20%), but simulation II had no limitation for the use of cottonseed hull in a diet. Using commonly used feed ingredients in Korea, we formulated least cost diets that meet nutrient requirement of a lactating dairy cow producing 36 kg of milk with combinations of 0.1% decrease or 0.1% increase in target milk fat or protein, respectively, from the national average milk fat (4.0%) and milk protein (3.1%). The contents of alfalfa and corn in a least-cost diet were decreased and those of tall fescue, whole cottonseed and rapeseed meal were increased with decreasing fat and/or increasing protein in milk. Scenarios that decreased target milk fat percentage from 4.0% to 3.9% reduced feed cost by 2 won per kg. Due to decrease in feed intake, daily feed cost was even more reduced (136 won per head) by decreasing target milk fat percentage. Increase in target milk protein percentage from 3.1% to 3.2% reduced feed cost by 6 won per kg. Among scenarios simulated, the least feed cost was obtained in scenario aimed for 3.9% fat and 3.2% of protein in milk. We conclude that a feeding practice for increasing milk protein percentage does not directly increase feed cost. In addition, feeding practices that increase protein content in milk is expected to improve economic life-span and reproductive performance of dairy cows.

• Architectural research
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• v.19 no.4
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• pp.101-108
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• 2017

The use of the air conditioner is increasing due to the rise of the outdoor temperature during summer, and the problems of the fire and the cooling performance deterioration are caused due to lack of maintenance of the outdoor unit. In particular, overall performance of cooling system and efficiency in outdoor units have been degraded due to an intake of high-temperature outdoor air thereby increasing cooling energy and operating cost. Thus, this study aimed to increase efficiency of outdoor units by evaporating and cooling intake air through mist spray at the intake port surface in the outdoor unit. The measurements results showed that total power consumption of misting outdoor unit compared to that of conventional outdoor units was reduced by 21% approximately, and total power consumption of the entire system including pump was reduced by 16.7%. In addition, the operating cost including water use was reduced by 13.5% approximately. In summary, if a mist-spray nozzle kit is installed in air-cooled outdoor units, the reduction in the usage of cooling energy and operating cost will be achieved without replacement of existing cooling systems or a large scale of repairs.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.25-36
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• 2017

The purpose of this study is to analyze traffic accident reduction effect of the introduction of motorcycle safety inspection. To analyze the effect of motorcycle inspection, we first estimate the number of defective motorcycles, and calculate the probability of accident occurrences caused by the defect using four year traffic accident data. Finally, we estimate the number of reduced accidents due to the introduction of the inspection and the total reduced accident cost. In this study, we analyzed three scenarios. It is analyzed that when the safety inspection system is applied to all motorcycles, 642 cases of traffic accidents and 325 million won per year of traffic accident costs are reduced. It is approximately 0.1% of 2014 total traffic accident cost of 26.5725 trillion won per year. It suggests that the cost of traffic accidents and traffic accidents due to vehicle factors are reduced when the safety inspection system is introduced.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.36-42
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• 2021

This study aims to examine whether there are some differences in the cost stickiness of R&D expenses of IT companies before and after the COVID-19 crisis. Before COVID-19, IT companies did not reduce R&D expenses even if sales decreased, resulting in cost stickiness. As a result, it appears that during the COVID-19, IT companies adjust R&D expenses in proportion to changes in sales. This is interpreted as a reduction in R&D investment, which takes a long time to create results, in case of a decrease in sales due to uncertainty in future management performance due to the COVID-19 pandemic. In other words, during the COVID-19 risk period, IT companies, like other companies, reduced R&D expenses as sales decreased, resulting in reduced cost stickiness. This study differs from existing literature in that it examines the impact of the COVID-19 pandemic on the R&D expenditure behavior of companies in the IT industry.

• Journal of Powder Materials
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• v.5 no.4
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• pp.293-298
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• 1998

In all larger hardmetal workshops furnaces for dewaxing, vacuum sintering or vacuum and overpressure sintering are today's standard. The furnace technology is well established. Equipment specifications such as operating overpressure, determine sintering cost, product quality, safety and reliability of the furnace and ultimately influence the competitiveness of the hard metal procucer in the global market. Essential furnace requirements are an efficient utilization of the furnace, an environmental friendly dewaxing system, high temperature uniformity, metallurgical treatment with process gases, as well as reduced cooling time by means of rapid cooling. Examples of reduced sintering costs are described achieved using a new design of vacuum sintering furnace with an improved rapid cooling device, cooling times are reduced by up to 45%. Additionally, a cost comparison of two different designs of vacuum overpressure sintering furnaces are included.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.7-8
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• 2015

Formwork accounts for 10% of the total construction cost and 30~40% of the framework cost, which is a fairly large part. Various system forms were developed for improved economic feasibility and constructability of formwork and for reduced construction duration. In general, the price of system forms per unit area is higher than that of the conventional method, yet the total construction cost can be reduced through higher reusability and constructability. However, if the reusability of forms is excessively increased to cut down the material cost, it may increase the construction duration, which will result in cost increase. On the other hand, if the reusability is decreased for reduction of construction duration, it may lead to cost increase caused by excessive input of materials. To solve such a problem, an algorithm for simplified reuse planning that meets the requirements of construction duration, cost, quality and safety is required. In this regard, the study intends to perform a fundamental research for development of reuse planning automation algorithms on system forms that are used on girders and beams.