• Journal of the Korean Society for Railway
• /
• v.19 no.1
• /
• pp.77-86
• /
• 2016

Before urban railway vehicles reach their design life-span, operating agencies should determine when to buy new vehicles. Previous LCC (Life Cycle Cost) studies were limited because they independently focused on existing vehicles based on costs that directly impacted only the operating agency without considering effects such as social costs and the reduction of maintenance costs. Thus, it is difficult to systematically determine when to buy new vehicles. This study investigated the operating and maintenance related costs, especially from additional expenses and social costs due to unexpected vehicle failures and safety accidents, and did an economic analysis of scenarios with different discount rates. Considering that the public is very concerned about safety after the Sewol ferry accident, additional costs, which include social costs, should be included in the analysis. This study shows that the economic priority of scenarios may change depending on whether those costs are included and on the discount rate. The results of this study can help in the decision-making process for the planning and buying of new trains.

• Journal of the Korean Statistical Society
• /
• v.32 no.1
• /
• pp.65-71
• /
• 2003

We consider the finite dam with compound Poisson inputs which is called M/G/1 finite dam. We assign some costs related to operating the dam and calculate the long-run average cost per unit time. Then, we find the optimal dam capacity under which the average costs is minimized.

• Korean Journal of Construction Engineering and Management
• /
• v.7 no.6
• /
• pp.185-192
• /
• 2006

The maintenance expenses of public rental housing have drastically been increased as facilities become obsolete. As an effective means of managing such a situation, accurate estimating of maintenance expenses and securing financial resources are crucially important. It, therefore, is necessary to analyze major factors affecting on maintenance expenses of public rental housing's facilities, and develop an effective instrument to estimate them. On the other hand, the U.S.A, where approximately 60 percent of public rental housing's operating costs are supported by the state, has already developed an effective tool to forecast operating costs based on several years' actual data. As a result, public rental housing has been operating with a reasonable level. However, there have been no remarkable researches and studies in this field in Korea. In this context, this study attempts to examine principal determinants of maintenance expenses of public rental housing's facilities, and their influence based on the latest five years' actual operating costs. This study may contribute to develop an objective and precise tool to forecast maintenance expenses of public rental housing.

• Korean Journal of Childcare and Education
• /
• v.9 no.5
• /
• pp.37-78
• /
• 2013

This study aimed to analyze the operating expenses and to estimate the standard child-care service cost in family childcare centers. The subjects were 442 family childcare centers in Korea and the data were analyzed with descriptive statistics by using SPSS 18.0 programs. The main results were as follows. Firstly, as the result of operating expenses analyses of family childcare centers, monthly average staff wages were 5,120,000 won and average general operating costs per month were 5,114,170 won. Therefore, monthly average operating costs of family childcare centers were totally 10,234,170 won. Secondly, the four standard child care service costs were calculated on the basis of the directors holding an additional teacher's position concurrently, whether the additional cooking staff were employed or not, and the type of lunch/snack materials.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.1
• /
• pp.21-27
• /
• 2012

We can efficiently collect crops or minerals by operating multi-robot foraging. As foraging spaces become wider, control algorithms demand scalability and reliability. Swarm robotics is a state-of-the-art algorithm on wide foraging spaces due to its advantages, such as self-organization, robustness, and flexibility. However, high initial and operating costs are main barriers in performing multi-robot foraging system. In this paper, we propose a novel method to improve the energy efficiency of the system to reduce operating costs. The idea is to employ a new behavior model regarding role division in concert with the search space division.

• Journal of Navigation and Port Research
• /
• v.38 no.6
• /
• pp.567-575
• /
• 2014

In recent times, an obvious strategy in liner shipping markets that has come to the fore is slow steaming. Nowadays, most liner shipping companies have decelerated the voyage speed to 15-18 knots on major routes, and some leading liner shipping companies have a plan to reduce it to below 15 knots. Slow steaming is helpful in reducing the operating cost and the amount of greenhouse-gas emissions on a single vessel with lower fuel consumption. However, it also creates various negative effects such as the opportunity cost, additional fixed costs and an in-transit inventory cost on a loop. Hence, the net operating cost on a loop is changing dynamically due to the changes of voyage speed based on various slow steaming effects. The aim of this study is to analyze the slow steaming effects in the liner shipping, and to find the best voyage speed that minimizes the operating cost on a loop. Moreover, this study suggests the recommendable strategy for liner shipping companies. To achieve the aim of this study, a simulation model has been designed using System Dynamics.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.5
• /
• pp.545-551
• /
• 2005

The main objective of fraud detection is to minimize costs or losses that are incurred due to fraudulent transactions. Because of the problem's nature such as highly skewed, overlapping class distribution and non-uniform misclassification costs, it is, however, practically difficult to generate a classifier that is near-optimal in terms of classification costs at a desired operating range of rejection rates. This paper defines a performance measure that reflects classifier's costs at a specific operating range and offers a cost-sensitive learning approach that enables us to train classifiers suitable for real-world credit card fraud detection by directly optimizing the performance measure with evolutionary programming. The experimental results demonstrate that the proposed approach provides an effective way of training cost-sensitive classifiers for successful fraud detection, compared to other training methods.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.4
• /
• pp.849-855
• /
• 2021

The purpose of this study is to analyze and compare Islamic commercial banks and Islamic banking units with the stochastic frontier analysis (SFA) method during 2014-2018. The data in research using Islamic commercial banks and Islamic banking units. There are 10 Islamic commercial banks and 5 Islamic banking units that meet the criteria of purposive sampling. The calculation of efficiency level using the SFA method with the function of production shows that Islamic commercial banks and Islamic banking units always experience an increase in efficiency every year with the average level of efficiency of Islamic commercial banks being 0.43994, while the average rate of efficiency of Islamic banking units is slightly higher at 0.47654. This shows that Islamic banking units are slightly more optimal in generating total financing in the period 2010-2014. The test results using Independent Sample T-Test can be concluded that there is no difference in the efficiency value between Islamic commercial banks and Islamic banking units. Operating costs are not significant and have a positive effect on the total financing; total assets have a significant effect and a positive impact on total financing; labor costs are not significant and have a negative effect on total financing.

• Korea Journal of Hospital Management
• /
• v.10 no.3
• /
• pp.45-66
• /
• 2005

The purpose of this study was to analyze related factors affecting profitability on general hospitals(300-499 beds). The data were derived from survey by the Korean Hospital Association on 33 hospitals during 10 years (from 1993 to 2002). Profitability was measured by 3 ratios - net profit to total assets, normal profit to total assets and operating margin to gross revenue - as dependent variables. Independent variables were classified by general factors (ownership, number of bed, period of establishment, region), financial factors (total asset turnover, current ratio, liabilities to total assets, personnel costs per operation profit, material costs per operation profits), productivity index(number of daily patient per nurse), the score of quality assurance activity and the time lag score. Multiple regression model was used in this study. First, Number of bed, region was not statistically significant for profitability. But ownership was affect positively to normal profit to total assets and operating margin to gross revenue. Private hospitals had higher profitability than that of public hospitals Second, the score of quality assurance activity was not statistically significant to profitability. Third, Those hospitals having more daily patient per nurse had significantly higher profitability than the others. Fourth, Those hospitals having higher proportion in total asset turnover had significantly higher profitability than other hospitals. But liabilities to total assets and liquidity ratio had no difference to the profitability. Those hospitals having higher proportion in personnel costs and material costs per operation profits had significantly lower hospital profitability than others.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1630-1641
• /
• 2010

LCC can be defined as "the sum of present values of investment costs, capital costs, installation costs, energy costs, operating costs, maintenance costs, and disposal costs over the life-time of the project, product, or measure." LCCA involves estimating the costs and timing associated with each alternative over a selected analysis period and conversion of those costs to economically comparable values considering the time-value of money. The several Excel-Based LCC tools found on the internet are described in this paper. Also, This paper performed an analysis of the existing LCC commercial tools, assessing various aspects of each program. The goal was to evaluate the best features of each tool and to identify the requirements for LCC evaluation of Urban Transit Vehicle. The LCC tools are developed to address problems in many different areas and a tool developed and structured for one area cannot generally be used in another area. No general LCC tool exists and if one is needed for Urban Transit Vehicle it has to be developed by the project. Since a full LCC can be very complex it is likely that this Excel-Based LCC tool should be a small and simple tool for quick cost estimates. This paper presents a LCC tool consisting of eight excel sheets, which are "Project", "CBS", "PBS", "PM", "CM", "Others", "LCC Result" and "Diagram".