• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.119-126
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• 2004

Location management is very important issue in wireless communication system to trace mobile users' exact location. In this study, we propose a dynamic location area management scheme which determines the size of dynamic location area considering each user's characteristic. In determining the optimal location area size, we consider the measurement data as well as the historical data, which contains call arrival rate and average speed of each mobile user. In this mixture of data, the weight of historical data is derived by linear searching method which guarantees the minimal cost of location management. We also introduce the regularity index which can be calculated by using the autocorrelation of historical data itself. Statistical validation shows that the regularity index is the same as the weight of measurement data. As a result, the regularity index is utilized to incorporate the historical data into the measurement data. By applying the proposed scheme, the location management cost is shown to decrease. Numerical examples illustrate such an aspect of the proposed scheme.

• 산업공학
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• 제18권4호
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• pp.382-389
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• 2005

Location management is very important issue in wireless communication system to trace mobile users' exact location. In this study, we propose a dynamic location area management scheme which determines the size of dynamic location area considering each user's characteristics. In determining the optimal location area size, we consider the measurement data as well as the historical data, which contains call arrival rate and average speed of each mobile user. In this mixture of data, the weight of historical data is derived by linear searching method which guarantees the minimal cost of location management. We also introduce the regularity index which can be calculated by using the autocorrelation of historical data itself. Statistical validation shows that the regularity index is the same as the weight of measurement data. As a result, the regularity index is utilized to incorporate the historical data into the measurement data. By applying the proposed scheme, the location management cost is shown to decrease. Numerical examples illustrate such an aspect of the proposed scheme.

• 한국건설관리학회논문집
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• 제7권5호
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• pp.167-176
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• 2006

현재 재건축사업은 추진 의사결정과 관련한 확정된 지표나 기준이 없이 막연한 수익성에 대한 기대를 토대로 시행되고 있으며, 사업시행과정 에서 직면하게 되는 제반 위험 에 대해 경험 적으로 대응하고 있는 실정이다. 또한 재건축조합이나 시공예정 회사들이 제공하는 관리처분계획에 포함된 수익성에 관한 정보는 결정론적 분석을 통한 단순한 예측에 불과하여 재건축을 시행하는 과정에서 결과가 수정되는 것이 일반적이다. 즉 수익성에 대한 예측이 재건축시행 과정상의 유동적인 상황에서 변경됨에 따라 예측결과에 대한 신뢰도는 근본적으로 내 외적인 한계를 갖고 있다. 본 연구는 재건축사업의 수익성에 영향을 미치는 변수들을 확률적으로 평가하여 수익과 위험을 동시에 분석하는 수익성예측모델을 개발하고, 사례연구를 통해 개발모델의 적합성을 검증하여 기존의 결정론적 접근방식이 갖는 한계를 극복하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 전기설비
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• pp.37-39
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• 2005

When we have been estimated construction costs, till now, we are used to costs accumulating method of each items based on standard labors rates. But there are some problems of its methods. Our governments are applied to a historical construction costs estimation system for building construction and civil engineering works from January 2004. The electrical construction works are forecasted that applied to historical construction cost estimation systems. This paper is showed to development of electrical construction cost index for estimation of historical costs and contract prices.

• 대한토목학회논문집
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• 제34권2호
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• pp.667-676
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• 2014

본 연구는 제주특별자치도 내 실적공사비가 적용된 도로현장을 중심으로 물가변동에 따른 실적공사비 등락률 산정의 문제점을 분석하기 위하여 실시되었다. 본 연구를 위하여 제주특별자치도 내 9개 도로공사 현장을 중심으로 실적공사비방식, 표준품셈방식, 건설공사비지수방식에 따른 등락률을 비교 분석하였다. 분석결과 9개 현장 중 약 56%인 5개 현장에서 실적공사비의 지수조정률이 표준품셈과 건설공사비지수의 지수조정률에 비해 낮게 산정되었다. 이는 실적공사비가 적용됨에 따라 물가변동으로 인한 계약금액 조정 성립요건이 지연되고 있다는 것을 알 수 있으며, 이에 따라 공사 준공 전 물가변동으로 인한 계약금액 조정횟수의 감소와 함께 물가변동금액 역시 차이를 보일 수 있음을 의미한다. 또한, 건설공사비지수 사례분석 결과, 도로부문에 대한 지수를 적용하여 지수조정률을 산출하였으나 지수조정률이 2.0%~9.4%까지 산정되어 이는 공사금액 및 물가변동 적용시기에 따라 상당한 영향을 미치는 문제점이 나타났다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.444-447
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• 2006

건설 프로젝트가 성공적으로 수행되기 위해서는 각종 제반 관리업무가 상호 밀접한 관계성을 유지하면서 프로젝트를 수행해야한다. 이중 공정관리는 인력, 자재, 장비, 원가 등 여러 가지 건설공사에 필요한 자원에 대한 관리업무를 시간적인 흐름 속에서 모델화 시킨 것으로, 공정관리의 원활한 수행은 프로젝트의 성공에 직접적인 영향을 주게 된다. 현행 공정관리 업무 프로세스에서 공사기간의 산정시 가장 중요하게 고려해야 할 점은 작업의 생산성은 투입되는 자원의 양과 질에 의해서 영향을 받으며, 이러한 자원의 특성은 투입비용으로 나타나게 된다는 것이다. 본 논문의 목적은 현장에서 사용되는 인력과 장비 등 자원투입 비용을 중심으로 생산성을 분석하고, 보다 현실성 있게 생산성 테이터를 공정계획의 수립시 작업기간 산정에 활용하는 방안을 제시하는 것이다. 본 연구에서 작업비용은 투입자원의 가격을 기준으로 산정했으며, 투입자원 비용과 작업량을 비교 ${\cdot}$ 검토하여 소요되는 작업기간을 예측한다. 이와 같은 공정데이터의 활용은 데이터베이스를 기반으로 하는 공정관리의 전 단계로써 자원투입 비용을 고려한 공정관리 방안을 제시하고, 이에 대한 타당성을 검토했다.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.488-493
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• 2013

Accurate initial cost estimates are essential to effective management of construction projects where many decisions are made in the course of project management by referencing the estimates. In practice, the initial estimates are frequently derived from historical actual cost data, for which standard distribution-based techniques are widely applied in the construction industry to account for risk associated with the estimates. This approach assumes the same probability distribution of estimate errors for any selected estimates. This assumption, however, is not always satisfied. In order to account for the probabilistic nature of estimate errors, an alternative method for measuring the risk associated with a selected initial estimate is developed by applying the Bayesian probability approach. An application example include demonstrates how the method is implemented. A hypothesis test is conducted to reveal the robustness of the Bayesian probability model. The method is envisioned to effectively complement cost estimating methods that are currently in use by providing benefits as follows: (1) it effectively accounts for the probabilistic nature of errors in estimates; (2) it is easy to implement by using historical estimates and actual costs that are readily available in most construction companies; and (3) it minimizes subjective judgment by using quantitative data only.

• 한국경영과학회지
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• 제39권3호
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• pp.51-61
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• 2014

In this paper, we deal with developing a cost estimation relationships (CER) for Korean maneuverable weapons systems using historical production cost. To develop the CER, we collected the historical data of the production cost of four tanks and five armored vehicles. We also analyzed the Required Operational Capability (ROC) of the weapons systems and chose cost drivers that can compare operational capabilities of the weapons systems We used Forward selection, Backward selection, Stepwise Regression and $R^2$ selection as the cost drivers which have the greatest influence with the dependent variables. And we used Principle Component Regression, Robust Regression and Weighted Regression to deal with multicollinearity and outlier among the data to develop a more appropriate CER. As a result, we were able to develop a production cost CER for Korean maneuverable weapons systems that have the lowest cost errors. Thus, this research is meaningful in terms of developing a CER based on Korean original cost data without foreign data and these methods will contribute to developing a Korean cost analysis program in the future.

• 한국국방경영분석학회지
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• 제36권1호
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• pp.29-38
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• 2010

In Korea weapon system acquisition processes, it's required a cost estimation report obtained from a commercial cost model. The PRICE model is generally used as a cost estimation model in Korea. However, the model uses American historical R&D data and it's output cost component is different from our cost component of defense accounting system. Also, we found that estimating results show about 10% of difference when we comparing with actual costs in 44 finished weapon acquisition projects. There are some limitations in calibration to increase an accuracy of the PRICE model because it's difficult obtain good real input data, detailed cost and technical data in low level WBS. So, only 8% of the defense R&D projects are calibrated and validation of calibration results is more difficult. Therefore, we studied the standard calibration process and performed the calibration about the MCPLXS/E parameters of the PRICE model based on actual cost data. In order to obtain a good calculation result, we collected the actual material costs from the defense industry companies. Our results can be used for an reference in similar weapon system R&D and production cost estimation cases.

• The Journal of Asian Finance, Economics and Business
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• 제9권8호
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• pp.71-80
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• 2022

This study aims to investigate the effects of fair value valuation of biological assets and bearer plants measured at historical cost on the cost of third-party capital. The study contributes to the agricultural sector and the International Accounting Standard - IAS 41, which has been modified to remove the requirement to apply fair value for bearer plants, one of the primary biological assets with no active market. For this, 182 companies from 39 countries were studied in the years 2020 and 2021, with information taken from the Thomson Reuters Eikon platform. The methodology involves regression by the ordinary least squares method based on the model of Daly and Skaife (2016). The results show that the biological asset at fair value does not influence the cost of debt and that the measurement of bearer plants at historical cost has no effect on the cost of debt. Fair value did not change the perceived cost of debt of the analyzed companies in the studied period, contrary to Daly and Skaife (2016). Finally, the cost of third-party capital can be influenced by other aspects related to profit quality, which were not examined in this paper, such as profit management.