• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.318-330
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• 2013

It is necessary to estimate the operating cost for constructing an urban railway system. The present study was thus carried out to develop an estimation function of the operating cost for a MRT(Medium-sized Rapid Transit) system. We selected seven independent variables that could influence the operating cost: the rolling stocks, the number of trains in operation, the length of the lines, the number of stations, the number of passengers per day, the frequency of train operation, and the number of depots. We performed a multiple regression using Excel. Three types of regression functions were thereupon developed. All of them proved to be appropriate after comparing the results of the estimated cost. It will therefore be possible to use one of these three types, depending on the assumptions of the independent variables.

• Water for future
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• v.28 no.1
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• pp.153-168
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• 1995

The purpose of this study is to develop an efficient model for the least cost design of multisite detention systems. The IDP (Incremental Dynamic Programming) model for optimal design is composed of two sub-models: hydrologic - hydraulic model and optimization model. The objective function of IDP is the sum of costs; acquisition cost of the land, construction cost of detention basin and pumping system. Model inputs include channel characteristics, hydrologic paramenters, design storm, and cost function. The model is applied to the Jung- Rang Cheon basin in Seoul, a watershed with detention basins in multiple branching channels. The application results show that the detention system can be designed reasonably for various conditions and the model can be applied to multi-site detention system design.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.5
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• pp.276-284
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• 2013

A stochastic expected cost model has been suggested by combining the nonlinear cumulative damage model with the expected cost model together which can be useful for doing the preventive optimal-maintenance of the armor units of rubble-mound breakwaters. The suggested model has been satisfactorily calibrated by comparison of the results from others models, also the sensitivity analysis has been carried out in detail under the variation of the associated parameters with the model. The optimal repair times can be directly evaluated by minimizing the expected cost rates that depend on the social importances, damage intensity functions and resistance limits. Finally, the present cost model has been straightforwardly applied to the armor units of rubble-mound breakwaters. Based on the assumption of turning the damaged structure back to the state as good as new after repairs, the required optimal repair times and magnitudes can be determined quantitatively in terms of the optimum balance between the costs and benefits on the preventive maintenance.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1525-1526
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• 2015

본 논문에서는 일반용 전기설비 안전점검으로 인한 전기화재 예방효과를 정량적으로 나타내기 위하여 전기화재 예방효과를 비용효과 분석방법을 통하여 정량적으로 제시하였다. 안전점검 실시유무에 따른 추상적인 분석모형을 개발하고, 개발된 분석모형을 정량적으로 나타내기 위한 수학적 논리를 이용한 수리모형으로 제안하고, 제안된 수리모형에 5년 동안에 일반용 전기설비 안전점검 실적과 화재 통계자료를 적용하여 전기안전점검에 대한 화재예방효과를 비용효과분석을 통하여 정량적으로 산출하였다.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.211-221
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• 2008

This dissertation studied the psychological cost, which converted the mental pain suffered by the victim of a traffic accident and his/her family, friends and people around him/her into social costs. Three methodologies - Choice Experiments, Direct Question and Dichotomous Choice Question - were used to design questionnaires, and models were built for each questionnaire design method. When building models, a logit model was used, which is used most frequently in probabilistic choice model. And the tobitmodel was used to make direct questionnaires. When verifying these models, although there were some differences in each model, suitability of most models and credibility of each coefficient were meaningful around the credibility level of 95%. According to the analysis, domestic psychological cost produced through the assessment model of psychological cost was 15.63 million won per person or 5.1 trillion in total, assuming 37.1% of total traffic accident cost.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.211-217
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• 2019

In this study, we compare and analyze the attributes of the software development cost model according to the shape parameters change of the Type-2 Gumbel lifetime distribution using the NHPP model. In order to analyze the software failure phenomena, the parametric estimation is applied to the maximum likelihood estimation method, and the nonlinear equations are calculated using the bisection method. As a result, when the attributes of the cost curves according to the change of shape parameters are compared, it is found that the larger the number of shape parameters, the lower the software development cost and the faster the release time. Through this study, it is expected that it will be helpful for the software developers to search for the development cost according to the software shape parameters change, and also to provide the necessary information for the attributes of the software development cost.

• Spatial Information Research
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• v.16 no.1
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• pp.1-10
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• 2008

`Information measure model' and 'Information benefit model' for road plan are developed. In result of application to actual road project, 'Information measure model' showed same result with actual road plan, it can express qualitative element by 'Information' like safety, public discontent, etc. and 'Information benefit model' can evaluate present plan in the side of provider's and demader's 'benefit'.

• Electronics and Telecommunications Trends
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• v.13 no.1 s.49
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• pp.21-28
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• 1998

가입자망 투자비용은 전화망의 접속료를 구성하는 비용 요소 중 가장 중요한 부분이다. 본 논문은 대도시지역의 전화가입자망 구축에 소요되는 투자비용을 추정하고, 이러한 투자비용 산출을 위한 일반적인 비용모델의 개발에 관한 것이다. 서울을 대상지역으로 하여 주요 비용요소들이 정의되었고 선로기술, 지형특성, 가입자 수 등의 연관성이 분석되었다. 연구결과는 다사업자 환경에서 접속료 추정을 위한 비용모델 설계에 활용될 수 있다.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.31-40
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• 1998

본 연구의 목적은 기존의 Cell Transmission(1994, Daganzo) 교통류 이론을 기반으로 동적통행배정 모형을 개발하는 것이다. 이 모형은 동적 O-D 발생모듈, HOV 차선모듈, 분류부 분할모델, 링크비용함수 모듈, 최단경로 탐색 모듈등으로 구성된다. 이 모델에서 적용하는 교통류 모델은 각 링크를 동일한 특성을 가지는 셀로 구분하여 셀내의 진입시간과 진출시간을 계산하여 링크비용을 계산하는데 이것은 비용의 과대·과소 추정을 피할 수 있으며 교통지체 현상을 현실적으로 표현해 줄 수 있는 장점이 있다. 또한 HOV 차선 모듈에 의해 수단별 교통류 진행 및 비용고려가 가능하며 HOV 차선의 평가 및 분석이 가능하다. 기존의 동적통행배정모형은 매 시간대별 출발지에서 균형상태를 추구하는 통행배정기법을 사용하고 있지만 이 모델은 분류되는 노드를 가상의 출발점이라고 가정하여 각 시간대별로 최단경로를 탐색하여 균형상태를 추구해나가는 기법을 적용하고 있다. 각 셀별 차량을 목적지별, 차종별, 대기시간별로 추적하여 진행시키며 분류부에서는 최단경로를 탐색하여 배분된다. 또한 진행하고자 하는 셀의 용량과 현재 셀의 밀도를 고려함으로서 용량제약 하에서의 동적통행배정모형을 적용하고 있다. 이 모형은 고속로의 합류부 및 분류부의 교통특성을 세밀히 분석할 수 있으며, TCS 및 램프미터링과 접목하여 고속도로 운영에 이용될 수 있으며, 고속도로 중·장기적인 계획에 이용될 수 있다.

• Environmental and Resource Economics Review
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• v.22 no.4
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• pp.691-726
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• 2013

We develop a hybrid model which allows the change in electricity generation mix by adding the electricity-sector components of bottom-up model to the conventional CGE model. The electricity sector is represented as a sum of separate generation technologies, each of which has the form of DRTS (Decreasing Returns to Scale) production function, unlike the conventional CGE model. We compare the effects of the 30% emission reduction target using the hybrid model with those using the conventional CGE model. The cost of meeting the target is lower with the hybrid model than the conventional CGE. It is consistent with previous studies in that adding the bottom-up components to the top-down model reduces the cost of emission reduction. In an extra analysis we find that an additional regulation like RPS (Renewable Portfolio Standard) increases the cost.