• 청정기술
• /
• 제28권2호
• /
• pp.138-146
• /
• 2022

Electricity has become a factor that dramatically affects the market economy. The day-ahead system marginal price determines electricity prices, and system marginal price forecasting is critical in maintaining energy management systems. There have been several studies using mathematics and machine learning models to forecast the system marginal price, but few studies have been conducted to develop, compare, and analyze various machine learning and deep learning models based on a data-driven framework. Therefore, in this study, different machine learning algorithms (i.e., autoregressive-based models such as the autoregressive integrated moving average model) and deep learning networks (i.e., recurrent neural network-based models such as the long short-term memory and gated recurrent unit model) are considered and integrated evaluation metrics including a forecasting test and information criteria are proposed to discern the optimal forecasting model. A case study of South Korea using long-term time-series system marginal price data from 2016 to 2021 was applied to the developed framework. The results of the study indicate that the autoregressive integrated moving average model (R-squared score: 0.97) and the gated recurrent unit model (R-squared score: 0.94) are appropriate for system marginal price forecasting. This study is expected to contribute significantly to energy management systems and the suggested framework can be explicitly applied for renewable energy networks.

• 신재생에너지
• /
• 제10권2호
• /
• pp.40-47
• /
• 2014

This study is intended to analyze the appropriate scope for 9.9MW biomass cogeneration, feasibility and sensitivity according to changing market situation. In the study, the heat load is classified into three types to predict heat sales and find out the appropriate scope of thermal business that is operated in CHP 34.42 Gcal/h, PLBwg 70 Gcal/h of cogeneration. the feasibility is estimated based on internal rate of return (IRR) and net present value(NPV). the sensitivity is analyzed in terms of biomass fuel cost, unit price of heating cost, investment cost, SMP unit price and REC unit price.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2022년도 봄 학술논문 발표대회
• /
• pp.196-197
• /
• 2022

This study aims to come up with the revision of construction standard unit price for concrete pavement works to improve its applicability and availability by a construction site survey. Construction site survey was conducted from March to November 2021 with 36 construction sites. This results of the revision are expected to support to public construction project owner or estimator in construction cost estimation works.

• 한국조경학회지
• /
• 제29권6호
• /
• pp.72-81
• /
• 2002

The purpose of this study is to determine the impact of the soil load for artificial ground on a building's structural expenses. Three types of soil - 100% soil, soil mixed with 50% perlite, and 100% artificial soil - were used for this study. A one story concrete steel building specific to each soil load was designed, and then, the cost of steel and concrete used for the design was estimated. As the result of this study, the structural expenses in the case of 5:5 mixed soil can be reduced about 17% compare with 100% soil. Using artificial soil, the structural expenses can be cut about 32% compare to 100% soil and about 12% less when 5:5 mixed soil is used. However, considering total expense which includes the structural expense and soil expense, the expense of 5:5 mixed soil have an increase 25% compared with 100% soil. In the artificial soil, the total expense is 45% more expensive than 100% soil and 17% higher when 5:5 mixed soil is used because of the high unit price of artificial soil. This study expected substantial savings in structural cost as the soil-load was lightened. But, savings were significantly reduced because the unit price of the artificial soil is much more expensive than the price of the natural one. Therefore, further research on methods of reducing the unit price of the artificial soil should be conducted in order to extend green space on to artificial ground.

• KIEAE Journal
• /
• 제7권3호
• /
• pp.11-20
• /
• 2007

The purpose of this study is to analyse the effects of the eco-friendly factors on the apartment housing price rise and to suggest the desirable way of marketing strategy for apartment housing. For the analysis, the data of apartment sites in Seoul had been collected from September 2006 to February 2007. The data consisted of 95 apartment sites in Seoul. Data were analyzed with descriptives, crosstabs, and discriminant analysis by SPSS/PC for Window. Following result was obtained. The eco-friendly apartment housing price rate in Seoul was determined by eco-friendly landscape, green space rate, house unit size, installment sale price per pyeong, floor space index, distance from subway station when it was not considered the impact of building age, construction company's brand, and autonomous districts. Findings of this research can provide valuable information for marketing strategy of housing construction company.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.822-823
• /
• 2007

It is easily can be expected that Korea cannot be free under the regulation, because Korea is one of the major $CO_2$ emitter in the world. Even though Korea currently doesn't have any obligation to mitigate the carbon emission, power industry needs to study the effect of that. this paper aims to analyze the change of economic loading order for generation dispatch by various carbon price, looking at each plant's or generator's variable generation cost per unit electricity(kWh) that consists of basic generation price calculated by automatic generation system planning model, WASP 4.0, and $CO_2$ price per unit electricity generation.

• 조명전기설비학회논문지
• /
• 제28권7호
• /
• pp.97-105
• /
• 2014

This article examines the causality relationship among SMP, base-load share, LNG import price, and exchange rate in Korean power market during 2002~2012, using unit root test, cointegration test, and vector error correction model(VECM). The cointegration test shows that 4 variables without unit root have been in the long-run causality. As the results of ECM, SMP is analyzed to have been unilaterally caused from LNG import price and base-load share in the shot-run, while it has been unilaterally caused from LNG import price and exchange rate in the long-run. This article has the following policy implications: the adjustment of exchange rate to reduce he risk of LNG import price and the proper securement of base-load share for the long-run stability of SMP.

• 국제지역연구
• /
• 제15권1호
• /
• pp.219-240
• /
• 2011

본 연구는 주가 및 부동산가격 변화에 의한 화폐수요함수의 자산효과를 분석하였다. 부동산가격 자료의 획득이 가능한 10개국, 25개 통화단위를 대상으로 분석하였으며, Johansen 공적분 검정에 추가하여 Pesaran, Shin and Smith의 한계검정을 적용하였다. 또한, 효율적인 공적분벡터의 추정을 위하여 Stock and Watson의 DOLS를 적용하였다. 분석결과, 화폐수요함수에 주가와 부동산가격을 포함시킬 경우 장기균형관계의 성립 가능성이 월등히 증가하였다. 특히 ARDL-한계검정에 의하면 12개 통화단위는 자산 가격을 포함하는 경우에만 공적분관계가 존재하는 것으로 나타났다. 이러한 결과들은 자산가격의 변화가 장기화폐수요에 매우 유의한 영향을 준다는 의미이다. DOLS에 의한 공적분 벡터의 추정결과에서도 주가와 부동산가격이 매우 유의한 영향을 주는 것으로 나타났다. 주가는 12개 통화단위에서 통계적으로 유의한 영향을 미치는 반면 부동산가격은 19개 통화단위에서 통계적으로 유의하였다. 특히 부동산가격은 싱가포르 M1을 제외하고 나머지 모든 국가의 통화단위에서 통계적으로 유의하게 나타나 장기 화폐수요함수 추정에서 부동산시장의 중요성이 부각된다. 한편 주가와 부동산가격의 계수부호나 크기는 국가별로, 통화단위별로 상이하게 나타났다.

• 한국산학기술학회논문지
• /
• 제21권10호
• /
• pp.589-601
• /
• 2020

건설공사의 적정한 공사비산정을 위하여 건설공사의 실적을 토대로 하는 표준시장단가가 작성되고 있으며, 공공건설공사의 예정가격 작성을 위한 기초자료로 활용되고 있다. 현재 표준시장단가는 건설현장 시장상황 및 시공상황을 고려하여 산출되고, 보정기준을 마련하기 위하여 중장기 정비계획을 수립하여 공종별 시공실태 및 시장가격 변화에 대한 현장조사를 수행하고 있다. 그러나 중장기계획 정비가 5년 이상으로 장기화되고, 일시적 정비로는 중요도가 높고 단가변동성이 큰 핵심공종들에 대한 지속적인 관리가 어려운 문제점이 발생되고 있다. 이에 본 연구는 표준시장단가 적기 개정을 통한 적정공사비 확보를 위하여 표준시장단가 핵심공종을 도출하고, 중점관리방안을 제시하였다. 중요도 및 단가변동성 분석을 통하여 35개 조사그룹에 해당하는 242개 핵심공종들을 도출하였으며, 공종들의 중요 수준을 고려하여 중점관리방안을 제시하였다. 제시된 핵심공종 및 중점관리방안을 통하여 중요 공종들의 적기 개정이 가능할 것으로 판단된다. 또한 향후 중장기계획 재수립시 핵심공종에 대한 지속적인 관리방안을 수립하여, 공사비산정기준의 적절성을 적시적재에 반영할 수 있도록 기반을 마련하였다.

• 한국인터넷방송통신학회논문지
• /
• 제21권4호
• /
• pp.171-176
• /
• 2021

본 논문은 설비 설치비용과 판매단가로 구성된 다수의 구매처 입찰정보로부터 구성품을 구매함에 있어 최소의 비용으로 구매하기 위해 구매처와 구매 물량을 선정하는 입찰평가 문제를 다룬다. 이 문제에 대해 기존에 알려진 방법은 분기한정 법(BB)과 분기절단 법(BC)이 알려져 있다. 그러나 이들 방법으로 얻은 해가 최적 해가 되지 않는 문제점이 있다. 본 논문에서는 판매단가 순위 또는 설치비용 순위 우선 구매물량 배정원칙을 적용하여 초기 실현 가능 해를 얻고, 판매단가 또는 설치비용을 고려하여 물량을 이동(구매업체 변경)시키는 최적화를 수행하는 방법을 제시하였다. 제안된 방법을 실험 데이터에 적용한 결과 BB와 BC에 비해 구매비용을 크게 절감할 수 있었다.