기술발전에 따른 생존모형 선정

오현승(H S Oh),김종수(C S Kim),이한교(H K Rhee),임동순(D S Yim),조진형(J H Cho) 한국산업경영시스템학회 2009 한국산업경영시스템학회지 Vol.32 No.4

In a technological driven environment, a depreciation estimate which is based on traditional like analysis results in a decelerated rate of capital recovery This time pattern of technological growths models needs to be incorporated into life analysis framework especially in those industries experiencing fast technological changes The approximation technique for calculating the variance can be applied to the six growth models that were selected by the degree of skewness and the transformation of the functions For the Pearl growth model, the Gompertz growth model, and the Weibull growth model, the errors have zero mean and a constant variance over time However, transformed models like the linearized Fisher-P교 model, the linearized Gompertz growth model, and the linearized Weibull growth model have increasing variance from zero to that point at which inflection occurs It can be recommended that if the variance of error over time is increasing, than a transformation of observed data is appropriate

맨홀 위치 알림이

오현승(H. S. Oh),김용주(Y. J. Kim),안상규(S. G. An),김주영(J. Y. Kim),이기성(G. S. Lee),송태종(T. J. Song),유창호(C. H. Yu) 한국재활복지공학회 2022 한국재활복지공학회 학술대회논문집 Vol.2022 No.11

ELG 방법을 활용한 제조설비의 경제적 감가상각률 추정방안

오현승(H. S. Oh),권세혁(S. H. Kwon),성일석(I. S. Sung),조진형(J. H. Cho) 한국산업경영시스템학회 2013 한국산업경영시스템학회지 Vol.36 No.1

Several different depreciation systems may be used for group depreciation. The vintage group procedure treats the same type of property placed in service during the same year as a distinct group for depreciation purposes; therefore an estimate of the probable average service life and net salvage ratio(s) of each individual vintage is necessary. The vintage group procedure calculates an accrual rate for each vintage and the accrual rate for an account for specific calendar year is the weighted average vintage accrual rate for that calendar year. A further refinement would be to divide each vintage into groups such that all of the dollars in a group have the same estimated life-an equal life group (ELG). Then each ELG is depreciated over its estimated life. The effect is to recover each dollar over the estimated number of years it is in service. Each vintage is divided into several equal life groups (ELGs) such that all the property in a specific ELG has the same estimated life. The accrual rate for each ELG is based on the estimated life of that ELG. The vintage accrual rate for a specific year is the weighted average ELG accrual rate for that calendar year. In this paper, we illustrate the calculations of vintage accrual rates for each of the ca lendar years by the ELG depreciation systems.

An Estimation of ASL in Appraisal :

H. S. Oh(오현승),S. J. Lee(이세재),J. H. Kwon(권정훈),N. Y. Jung(정남용),J. H. Cho(조진형) 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.2

Although the 1997 Raw Data of the National Wealth Statistical Survey (South Korea) is timely 20-year-old data, it is meaningful as a benchmarking in the capital stock estimations of Korea, which is estimated by PIM (permanent inventory method). In the case of machinery/equipment, it is the data that can analyze in depth the changes in the industrial structure of Korea. In the case of ASL (average service life) which has economic concept, since the change of ASL is not so large, ASL yielded by the Raw Data of the 1997 National Wealth Statistical Survey is meaningful as reference value for the ASL estimated by the Bank of Korea and the National Statistical Office. As you know Japan has changed its service life due to changes in its industrial structure. However, many of its assets are still used for the years indicated in Showa (before 1989). The same trend with other countries such as Japan. However, the United States is constantly devoted to assessing the useful ASL and value of assets by distinguishing between the Hulten-Wykoff models and those not. Korea has also benchmarked the useful ASL of the United States and Japan when it conducted its own survey every 10 years by due diligence until 1997. In this study, the ‘constraint’ Iowa curve estimation by the Raw Data of the 1997 National Wealth Statistical Survey is based on the age records of the assets and the maximum age of the assets appropriately derived. And then we made modified Iowa curve by smoothing. From this modified one, we suggested ASL by asset. After 1997, the vintage disposal data directly were collected by the National Statistical Office with Oh Hyun Seung, Cho Jin Hyung, in order to estimate the useful ASL. Since then, the B/S team of the Economic and Statistics Bureau of the Bank of Korea has been working on a new concept of content training.

제조설비의 실제적 감가상각을 위한 경제적 감가상각률 추정방안

오현승(H. S. Oh),권세혁(S. H. Kwon),조진형(J. H. Cho) 한국산업경영시스템학회 2014 한국산업경영시스템학회지 Vol.37 No.1

When the number of items of same type of industrial property is quite large, calculating depreciation for a group of such item may be more efficient than depreciating each item separately. Also, predicting the service life of a specific individual unit is very difficult to do with any degree of accuracy. Estimating the probable average service life (PASL) of many units (or dollars) is not an easy task; however, an average life of many units can probably be predicted with a much higher degree of accuracy than the life of some particular unit. Using the average of many units allows for some units having relatively short lives and some units having relatively long lives without specifying whether a particular unit will have a short or a long life. If the life of each vintage in an account are not estimated, then the broad group procedure can be used. The broad group procedure depreciates the several vintage in an account as a single group. The PASL for this procedure is the estimate of the average of lives of the individual dollars in the group. If the estimated PASL's of the vintages are not the same, then a weighted average PASL would have to be calculated for each calendar year. In this paper, we illustrate the calculations of accrual rates and the annual depreciation charge for each of the calendar years by the broad group depreciation procedure.

The Effect of QM Activities on the Management Results of Small and Medium sized Enterprises in South Korea

S. I. Jung(정수일),J. H. Kwon(권정훈),H. S. Oh(오현승),S. J. Lee(이세재),J. H. Cho(조진형) 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.2

In this study, a correlation between execution of quality management activities and their results was verified by applying the Malcolm Baldrige model (hereafter referred to as the MB model) as a quality management performance measurement indicator for small and medium enterprises (SMEs) in South Korea. To achieve this goal, we need to determine whether the categorical requirements in the MB model are recognized consistently in SMEs, as a prerequisite. To this end, factor analysis was conducted for measurement variables in each category, which revealed that the process indicator was made up of six factors and the outcome indicator was made up of five factors, like those configured in the MB model. This result can be interpreted to mean that the requirements in each category of the MB model were well produced and recognized consistently throughout SMEs in South Korea. In addition, the analysis of causality between the process indicator (quality management activities) and the outcome indicator (management results) showed high causality between them. Although the quality management levels of SMEs in South Korea are inferior to those of conglomerates or other national quality award-winning companies, this study is significant in that the causality between quality management activities and results was verified, since this study targeted SMEs in South Korea as the target of investigation. Thus, it is empirically proven that the MB model can contribute to improved management results for SMEs in Korea.

BG 방법을 활용한 제조설비의 경제적 감가상각률 추정방안

오현승(H. S. Oh),권세혁(S. H. Kwon),조진형(J. H. Cho) 한국산업경영시스템학회 2012 한국산업경영시스템학회지 Vol.35 No.1

When the number of items of same type of industrial property is quite large, calculating depreciation for a group of such items may be more efficient than depreciating each item separately. Several different depreciation systems may be used for group depreciation. If the life of each vintage in an account are not estimated, then the BG procedure can be used; the BG procedure puts all vintages of the same type of property into a single broad group for depreciation purposes. In this case, only an estimate of the PASL and the net salvage ratio for all the property in the broad group is needed to calculate the depreciation charge.

AREA 활용 전력수요 단기 예측

권세혁(S. H. Kwon),오현승(H. S. Oh) 한국산업경영시스템학회 2016 한국산업경영시스템학회지 Vol.39 No.1

It is critical to forecast the maximum daily and monthly demand for power with as little error as possible for our industry and national economy. In general, long-term forecasting of power demand has been studied from both the consumer’s perspective and an econometrics model in the form of a generalized linear model with predictors. Time series techniques are used for short-term forecasting with no predictors as predictors must be predicted prior to forecasting response variables and containing estimation errors during this process is inevitable. In previous researches, seasonal exponential smoothing method, SARMA (Seasonal Auto Regressive Moving Average) with consideration to weekly pattern Neuron-Fuzzy model, SVR (Support Vector Regression) model with predictors explored through machine learning, and K-means clustering technique in the various approaches have been applied to short-term power supply forecasting. In this paper, SARMA and intervention model are fitted to forecast the maximum power load daily, weekly, and monthly by using the empirical data from 2011 through 2013. ARMA(2, 1, 2)(1, 1, 1)₇ and ARMA(0, 1, 1)(1, 1, 0)₁₂ are fitted respectively to the daily and monthly power demand, but the weekly power demand is not fitted by AREA because of unit root series. In our fitted intervention model, the factors of long holidays, summer and winter are significant in the form of indicator function. The SARMA with MAPE (Mean Absolute Percentage Error) of 2.45% and intervention model with MAPE of 2.44% are more efficient than the present seasonal exponential smoothing with MAPE of about 4%. Although the dynamic repression model with the predictors of humidity, temperature, and seasonal dummies was applied to foretaste the daily power demand, it lead to a high MAPE of 3.5% even though it has estimation error of predictors.

An Appropriated Share between Revenue Expenditure and Capital Expenditure in Capital Stock Estimation for Infrastructure

J. H. Cho(조진형),S. J. Lee(이세재),H. S. Oh(오현승),J. H. Kwon(권정훈),N. Y. Jung(정남용),M. S. Kim(김명수) 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.2

At the Bank of Korea, capital stock statistics were created by the PIM (perpetual inventory method) with fixed capital formation data. Asset classifications also included 2 categories in residential buildings, 4 non-residential buildings, 14 constructions, 9 transportation equipment, 28 machinery, and 2 intangible fixed assets. It is the Korean government accounting system which is developed much with the field of the national accounts including the valuation, but until 2008 it was consistent with single-entry bookkeeping. Many countries, including Korea, were single-entry bookkeeping, not double-entry bookkeeping which can be aggregated by government accounting standard account. There was no distinction in journaling between revenue and capital expenditure when it was consistent with single-entry bookkeeping. For example, we would like to appropriately divide the past budget accounts and the settlement accounts data that have been spent on dredging into capital expenditure and revenue expenditure. It, then, tries to add the capital expenditure calculated to FCF (fixed capital formation), because revenue expenditure is cost for maintenance etc. This could be a new direction, especially, in the estimation of capital stock by the perpetual inventory method for infrastructure (SOC, social overhead capital). It should also be noted that there are differences not only between capital and income expenditure but also by other factors. How long will this difference be covered by the difference between the ‘new series’ and ‘old series’ methodologies? In addition, there is no large difference between two series by the major asset classification level. If this is treated as a round-off error, this is a problem.

선박운항 시뮬레이터 실험조건 축소화 연구

권세혁(S. H. Kwon),오현승(H. S. Oh) 한국산업경영시스템학회 2012 한국산업경영시스템학회지 Vol.35 No.1

Ship handling simulator is a virtual ship navigating system with three dimensional screen system and simulation programs. FTS simulation can produce theoretically infinite experiment tests without time constraint, but which results in collecting determinstic observations. RTS simulation can collect statistical observations but has disadvantage of spending at least 30 minutes for a single experiment. The previous studies suggested that the number of experiment conditions to be tested could be reduced to obtain random data with RTS simulation by focusing on highly difficult experiment condition for ship handling. It has the limitation of not estimating the distribution of ship handling difficulty for the route. In this paper, similarity and clustering analysis are suggested for reduction methodology of experiment conditions. Similarity of experiment conditions are measured as follows: euclidean distance of ship handling difficulty index and correlation matrix of distance differences from the designed route. Clustering analysis and multi-dimensional scaling are applied to classify experiment conditions with measured similarity into reducing the number of RTS simulation conditions. An empirical result on Dangin harbor is shown and discussed.