• Journal of the Korean Society of Industry Convergence
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• v.8 no.2
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• pp.85-95
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• 2005

The margin level in the futures market platys an important role in balancing the default probability with the investor's opportunity cost. In this paper, we investigate whether the movement of KOSPI200 futures daily prices can be modeled with the extreme value theory. Based on this investigation, we examine the validity of the margin level set by the extreme value theory. Moreover, we propose an expected profit-maximization model for securities companies. In this model, the extreme value theory is used for cost estimation, and a regression analysis is used for revenue calculation. Computational results are presented to compare the extreme value distribution with the empirical distribution of margin violation in KOSPI200 and to examine the suitability of the expected profit-maximization model.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1423-1431
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• 2016

When the sample size in a certain domain is too small to produce adequate information, small area model with random effects is usually used. Also, if we do not consider an inherent pattern which data possess, it considerably affects inference. In this paper, we mainly focus on modeling to handle increased variation of the Current Population Survey (CPS) median income as the Internal Revenue Service (IRS) mean income increases. In a hierarchical Bayesian framework, most estimations are carried out through the Gibbs sampler while the grid method is used to generate parameters from non-standard form. Numerical study indicates that the performance of proposed model is better than that of CPS method in terms of four comparison measurements.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.4
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• pp.466-475
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• 1999

A backward Dynamic Programming(DP) model for the optimal facility replacement decision problem during a finite planning horizon is presented. Multiple alternative challengers to a current defender are considered. All facilities are assumed to have finite service lives. The objective of the DP model is to maximize the profit over a finite planning horizon. As for the cost elements, purchasing cost, maintenance costs and repair costs as well as salvage value are considered. The time to failure is assumed to follow a weibull distribution and the maximum likelihood estimation of Weibull parameters is used to evaluate the expected cost of repair. To evaluate the revenue, the rate of operation during a specified period is employed. The cash flow component of each challenger can vary independently according to the time of occurrence and the item can be extended easily. The effects of inflation and the time value of money are considered. The algorithm is illustrated with a numerical example. A MATLAB implementation of the model is used to identify the optimal sequence and timing of the replacement.

• International Journal of Reliability and Applications
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• v.4 no.4
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• pp.183-190
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• 2003

Rail breaks and derailments can cause a huge loss to rail players due to loss of service, revenue, property or even life. Maintenance has huge impact on reliability and safety of railroads. It is important to identify factors behind rail degradation and their risks associated with rail breaks and derailments. Development of mathematical models is essential for prediction and prevention of risks due to rail and wheel set damages, rail breaks and derailments. This paper addresses identification of hazard modes, estimation of probability of those hazards under operating, curve and environmental condition, probability of detection of potential hazards before happening and severity of those hazards for informed strategic decisions. Emphasis is put on optimal maintenance and operational decisions. Real life data is used for illustration.

• Korean Journal of Adult Nursing
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• v.25 no.3
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• pp.275-288
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• 2013

Purpose: The purpose of this study was to perform an economic analysis and estimate the fee for the practices that carried out by Emergency Nurse Practitioner (ENP) using relative value scale (RVS) and its conversion factor. Methods: First, we developed ENP's RVS for 25 advanced nursing services based on ENP's workload and its time spent by survey. A cost analysis was performed to evaluate the conversion factor of ENP's RVS. The share of ENP's contribution to fee-for-service in emergency setting was also analyzed. Results: Calculation of the RVS of 25 advanced nursing practices showed a range of points from 73.4 to 296.3 and an average of 145.1 points. The relevant conversion factor for advanced nursing practices among ENP was estimated at 12.2~15.9 won. The contribution rate of ENP's advanced nursing practices in the relative value scale of the national health insurance was estimated at 13.1~17.0%. Conclusion: The practices of ENP are not compensated separately and its reimbursement is usually included in physician fee. An estimation of nursing fee and an independent fee related to ENP's services shows the contribution rate to total revenue. It suggests that emergency nurse practitioners be considered as a revenue source the in emergency room.

• Environmental and Resource Economics Review
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• v.24 no.1
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• pp.165-187
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• 2015

In this paper, we tested if the sewage subsidy from Korean Water Management Fund discourage sewage fee increase by Korean local governments, and consequently hinder water quality improvement. To examine this counter-incentive effect of Water manage Fund sewage subsidy, we estimated the effect of sewage subsidy on the ratio of sewage fee revenue to environmental treatment facilities' operation cost of local governments in 2009-12, using two-stage least square estimation. We found that the sewage subsidy has negative effect on the sewage fee revenue to sewage operation cost ratio. But, the statistical significance of this effect was sensitive to model specification. And the size was too small to conclude that the counter-incentive effect was economically significant.

• Health Policy and Management
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• v.29 no.2
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• pp.206-219
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• 2019

This paper aims to demonstrate current health expenditure (CHE) and National Health Accounts of the years 2018 constructed according to the SHA2011, which is a manual for System of Health Accounts (SHA) that was published jointly by the Organization for Economic Cooperation and Development (OECD), Eurostat, and World Health Organization in 2011. Comparison is made with international trends by collecting and analyzing health accounts of OECD member countries. Particularly, scale and trends of the total CHE financing as well as public-private mix are parsed in depth. In the case of private financing, estimation of total expenditures for (revenues by) provider groups (HP) is made from both survey on the benefit coverage rate of National Health Insurance (by National Health Insurance Service) and Economic Census and Service Industry Census (by National Statistical Office); and other pieces of information from Korean Health Panel Study, etc. are supplementarily used to allocate those totals into functional classifications. CHE was 144.4 trillion won in 2018, which accounts for 8.1% of Korea's gross domestic product (GDP). It was a big increase of 12.8 trillion won, or 9.7%, from the previous year. GDP share of Korean CHE has already been close to the average of OECD member countries. Government and compulsory schemes' share (or public share), 59.8% of the CHE in 2018, is much lower than the OECD average of 73.6%. 'Transfers from government domestic revenue' share of total revenue of health financing was 16.9% in Korea, lower than the other social insurance countries. When it comes to 'compulsory contributory health financing schemes,' 'transfers from government domestic revenue' share of 13.5% was again much lower compared to Japan (43.0%) and Belgium (30.1%) with social insurance scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.131-137
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• 2021

This study estimated acreage response functions for greenhouse paprika, greenhouse strawberry, open-land garlic, and open-land spinach by using Gyeongsangnamdo agricultural income data. The results show that the cultivation area for greenhouse paprika increased because the agricultural management costs decreased, and the risk of price volatility was relatively low. On the other hand, the cultivation area for greenhouse strawberries decreased due to increasing agricultural management costs and the greater risk of price volatility. In the case of open-land garlic and spinach, the cultivation area remained stagnant due to the greater risk of price volatility, despite increasing agricultural revenue. We derived several policy implications from our results. The risk of price volatility in agricultural products is greater for crops grown on land rather than crops grown in greenhouses. Therefore, the local government needs to adopt the "agricultural revenue guarantee insurance" in preference to crops grown on land rather than crops grown in greenhouses. On the other hand, in the case of greenhouse crops, agricultural management costs are very high. Thus, local government should focus on replacing old facilities and supplying smart-farm facilities that reduce agricultural management costs such as heating costs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.91-104
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• 2023

The records system is believed to have started in Italy in the 14th century in line with trade developments in Europe. In 1491, Luca Pacioli, a mathematician, and an Italian Franciscan monk wrote the first book that described double-entry accounting processes. In many countries, including Korea, the government accounting standards used single-entry bookkeeping rather than double-entry bookkeeping that can be aggregated by account subject. The cash-based and single-entry bookkeeping used by the government in the past had limitations in providing clear information on financial status and establishing a performance-oriented financial management system. Accordingly, the National Accounting Act (promulgated in October 2007) stipulated the introduction of double-entry bookkeeping and accrual accounting systems in the government sector from January 1, 2009. Furthermore, the Korean government has also introduced International Financial Reporting Standards (IFRS), and the System of National Accounts (SNA). Since 2014, Korea owned five national accounts. In Korea, valuation began with the 1968 National Wealth Statistics Survey. The academic origins of the valuation of national wealth statistics which had been investigated by due diligence every 10 years since 1968 are based on the 'Engineering Valuation' of professor Marston in the Department of Industrial Engineering at Iowa State University in the 1930s. This field has spread to economics, etc. In economics, it became the basis of capital stock estimation for positive economics such as econometrics. The valuation by the National Wealth Statistics Survey contributed greatly to converting the book value of accounting data into vintage data. And in 2000 National Statistical Office collected actual disposal data for the 1-digit asset class and obtained the ASL(average service life) by Iowa curve. Then, with the data on fixed capital formation centered on the National B/S Team of the Bank of Korea, the national wealth statistics were prepared by the Permanent Inventory Method(PIM). The asset classification was also classified into 59 types, including 2 types of residential buildings, 4 types of non-residential buildings, 14 types of structures, 9 types of transportation equipment, 28 types of machinery, and 2 types of intangible fixed assets. Tables of useful lives of tangible fixed assets published by the Korea Appraisal Board in 1999 and 2013 were made by the Iowa curve method. In Korea, the Iowa curve method has been adopted as a method of ASL estimation. There are three types of the Iowa curve method. The retirement rate method of the three types is the best because it is based on the collection and compilation of the data of all properties in service during a period of recent years, both properties retired and that are still in service. We hope the retirement rate method instead of the individual unit method is used in the estimation of ASL. Recently Korean government's accounting system has been developed. When revenue expenditure and capital expenditure were mixed in the past single-entry bookkeeping we would like to suggest that BOK and National Statistical Office have accumulated knowledge of a rational difference between revenue expenditure and capital expenditure. In particular, it is important when it is estimated capital stock by PIM. Korea also needs an empirical study on economic depreciation like Hulten & Wykoff Catalog A of the US BEA.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.495-508
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• 2010

The aim of this study is to develop a quantified water loss Index to evaluate and manage leakage scientifically for the reduction of non-revenue water in water distribution systems. For the purpose, unavoidable background leakage suggested from UK water industry and IWA, and allowable water leakage in accord with the concept of allowable water loss are proposed by analyzing the inflow into two study water districts and the short-term water use of each customer in the districts. The study distribution areas are selected among the metered districts with good maintenance of leakage after improvement activities in Nonsan, medium sized city in Korea. Estimation models of allowable leakage are developed by metering and analyzing the minimum night flow at residential and commercial areas in the city. In the results of the investigation, it is estimated that background night flow in residential area was larger than that of commercial area where the types of business shows small water use characteristics. Meanwhile, night flow and background water loss on internal plumbing systems show great differences for each district which is influenced much by the water use characteristics and facilities scale. Based on metering water use data in various districts, leakage management criteria can be established under the consideration of domestic conditions in Korea by analyzing separated real water use and background leakage and it is possible to apply into presentation of optimal leakage level and reasonable time for working activities for leakage reduction.