• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.642-643
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• 2011

스마트그리드 구현에 실시간요금제 적용이 핵심으로 등장하고 있다. 실시간요금제 적용 시 전력수요의 변동을 시뮬레이션하기 위하여 2005년부터 2009년의 전자식전력량계 계량데이터를 이용하여 전력 수요의 가격탄력성을 구하였다. 가격탄력성을 산출하기 위하여 시계열 분석과 횡단면 분석을 동시에 수행할 수 있는 패널모형 분석을 적용하였으며, 국내 전기요금에 대하여 계약종별, 산업분류별 가격탄력성을 실시간 요금제에 대비하여 1시간 단위로 구하였다. 국내 전력수요의 가격탄력성은 계약종별 및 산업분류별로 대부분의 경우 -0.1 이내로 산출되어 가격탄력성이 매우 낮게 나타났다. 산업분류별로 가격탄력성을 산출함으로써 통계적 유의수준이 높게 나타났다.

• IE interfaces
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• v.25 no.4
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• pp.422-430
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• 2012

In this article, we introduced the estimation method by 'Safety Integrity Level'(SIL) for the criterion of safety assurance and performed a case study on a flame scanner. SIL requires probabilistic evaluation of each set of equipment used to reduce risk in a safety related system. FMEDA(Failure Modes, Effects and Diagnostic Analysis) method is widely used to evaluate the safety levels and provides information on the failure rates and failure mode distributions necessary to calculate a diagnostic coverage factor for a part or a component. Basically, two parameters resulting from FMEDA are used for SIL classification of the device : SFF(Safe Failure Fraction) and PFD(Probability of Failure on Demand). In this case study, it is concluded that the flame scanner is designed to fulfill the condition of SIL 3 in the aspect of SFF and PFD.

• IE interfaces
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• v.25 no.3
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• pp.338-346
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• 2012

Regarding the green environment, it is important to boost the spread of environmentally friendly vending machines and to operate the vehicles for their inventory replenishments while minimizing emissions of greenhouse gases. In general, the vending machine management company lacks capability to operate the supply chain effectively in an integrated way under the dynamic, complex, and stochastic environment. This paper presents a decision support system, termed DSSVM, for the operations of the general and smart vending machine supply chains with stock-out-based, one stage item substitution in a green logistics environment. The DSSVM supports the estimation of item demand and substitution probabilities, determination of operation parameters, supply chain analysis, what-if analysis, and $CO_2$ analysis for which various analytical models are employed.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.1
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• pp.45-59
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• 2013

A long-term forecasting method for a new product in early stage of diffusion is proposed. The method includes a constrained non-linear least square estimation with the logistic diffusion model. The constraints would be critical market informations such as market potential, peak point, and take-off. Findings on 20 cases having almost full life cycle are that (i) combining any market information improves the forecasting accuracy, (ii) market potential is the most stable information, and (iii) peak point and take-off information have negative effect in case of overestimation.

• Journal of Computing Science and Engineering
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• v.6 no.4
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• pp.310-319
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• 2012

Next generation wireless receivers demand low computational complexity algorithms with high computing power in order to perform fast signal detections and error estimations. Several signal detection and estimation algorithms have been proposed for next generation wireless receivers which are primarily designed to provide reasonable performance in terms of signal to noise ratio (SNR) and bit error rate (BER). However, none of them have been chosen for direct implementation as they offer high computational complexity with relatively lower computing power. This paper presents a low-complexity power-efficient algorithm that improves the computing power and provides relatively faster signal detection for next generation wireless multiuser receivers. Measurement results of the proposed algorithm are provided and the overall system performance is indicated by BER and the computational complexity. Finally, in order to verify the low-complexity of the proposed algorithm we also present a formal mathematical proof.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.2
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• pp.69-80
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• 1998

The optimal reservoir storage capacity is needed to be determined at the stage of reservoir planning. The reservoir storage capacity should be based on water balance between demand and supply, and meet the water deficity during the growing season. However, the optimal reservoir storage capacity should be determined considering benefit-cost analysis for the project. In this study, Two models are developed. The one is the RSOM(Reservoir Storage Optimization Model), that is consisted by three submodels, MROPER (Modified Reservoir OPERation model), RESICO(REservoir SIze and the construction COst computation) model. And the other is the BECA(BEnefit-Cost Anaysis) model. For model application, three districts, Chungha, Ipsil and Edong were selected. The relative difference of B/C ratio between project planning data and estimation by RSOM is 17.9, 15.0 and 7.3% respectively, which may be applicable for water resources development feasibility planning.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.59-74
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• 2016

Electricity sales are directly measured from individual consumers, which could minimize the time gap between data collection and public announcement. Furthermore, industrial electricity sales are highly linked with production and output. Therefore, industrial electricity consumption can be used to track production and output in real time. By using the high-frequency data of industrial electricity sales, this study develops the daily electricity business index (DEBI) to capture the daily economic status. The steps used to formulate DEBI are as follows: (1)selection of the explanatory variables and period, (2) amendment of the seasonal adjustment to eliminate daily temperature and effective day effects, (3) estimation of the weighted value via variables by using PCA, (4) calculation of DEBI and commencement of validation tests. Our empirical analysis and the Hodrick-Prescott filter analysis show that DEBI is highly related to existing economic indices.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.507-513
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• 2004

In the railway system, transportation plan corresponds to a m aster plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the railway operation company, and it includes several sub-planning activities such as train operation frequency plan, train (schedule) plan, train capacity assignment plan, and rolling stock requirement plan. In these sub- planning processes, train can be con side red as a product for providing customer services, and customer demands and operational advantages must be considered. In this paper, we present an effect estimation system for the train capacity pattern in a train schedule, and the effect of capacity pattern can be expressed as minimum spilled demand, minimum train service cost, and maximum train revenue or profit.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.53-57
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• 2006

현재, 많은 분야에서 데이터 모델링을 지원하는 GIS관련 프로그램으로 ArcObject 컴포넌트를 제안하고 있다. 특히 수자원분야에서 유역과 하천네트워크의 정확하고 효과적인 표현을 위해 ArcHydro Model이 개발되었으며 다양한 분야에서 활용되고 있다. 본 연구에서는 안성군 고삼면의 안고용수구역을 대상으로 ArcHydro Model을 이용하여 관개 네트워크를 구성하기 위해 유역경계, 하천망, 수리시설물의 위치도, 수혜구역도 등의 기본 공간자료들을 구축하고, 이 자료들을 이용하여 수리시설물에 따른 수혜구역을 가시적으로 확인가능하도록 하기 위해 하천의 위상관계를 정립하고 공간자료간의 연계성을 구성하였다. 또한 수리시설물의 농업용수 수요공급량의 정량적인 정보를 획득하기 위하여 ArcHydro Model에 한국농촌공사에서 개발한 AWDS (Agricultural Water Demand and Supply Estimation System. 농촌용수 수요공급량 시스템)와 연계하고, 시설물정보, 수요량분석, 공급량분석을 할 수 있는 메뉴를 구성하여 그 정보를 획득하였다.

• Proceedings of the KSRS Conference
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• v.2
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• pp.909-912
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• 2006

In this paper a method for remotely-sensed assessment of eutrophication was experimented. The water samples were collected for analysis of COD (chemical oxygen demand) and nutrients concentration, and the remote sensing reflectance data at the sampling points were synchronously measured using above-water method in two cruises, which were conducted in the Pearl River Estuary in January 2003 and January 2004 respectively. Based on the in-situ data the local algorithms for estimation of concentration of nutrients (P and N) and COD were developed by Partial Least Squares (PLS) regression. The algorithms were then applied to atmospheric-corrected SeaWiFS data and the COD and nutrients concentration in Pearl River Estuary were estimated. And then the assessment of eutrophication was carried out by comparison of the estimated nutrients and COD value with the water quality standard. The results show that the whole estuary is seriously in eutrophication.