• 제목/요약/키워드: Demand current

검색결과 2,230건 처리시간 0.029초

지진기록 선택에 따른 요구지진 하중의 변화 (Variability of Seismic Demand According In the Selection the Earthquake Ground Motion Groups)

  • 황수민;한상환
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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    • pp.417-422
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    • 2004
  • It is the challenging task to predict seismic demand for structural design. In current seismic design provisions such as UBC, NEHRP, ATC 3-06, the seismic demand is calculated using the response spectrum with response modification factor (R). This paper investigates variability of seismic demand according to selecting the earthquake ground motion groups. Different Earthquake sets used by Miranda, Riddell and Seed selected were used in this study. Earthquake sets selected by authors include 62 sets of near field ground motion and 19 sets one pulse ground motion. Linear Elastic Response Spectrum (LERS), the variation of performance points of calculated by Capacity Spectrum Method (CSM) were considered with respect to the different sets of earthquake ground motions.

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KTX 특정(조건부) 할인상품 운영에 관한 사례 연구 (Initial Operation Case Study on KTX Special Class)

  • 한은영;주상화
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.758-762
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    • 2007
  • Revenue management is a new approach method to solve the problem of supply and demand, and one of fields which is diffused quickly at the service enterprise to use perishable-asset like the transportation business. It is based on multiple fare policy that discount charge reservation should be received if the benefit value of current discount fare is more than expected profit of the normal fare reservation it will be able to occur in future when suitable goods is sold to the customers at discount fare, at the time they want, and at assigned seat by controlling supply and demand from market. In this research, I will review on initial operation case for special class goods that the seat which is limited is assigned at some of train and portion of KTX for demand dispersion and new demand creation at peak time, put a limit in purchase conditions, and provides discounted fare. I will also try to find implication for strategic operation.

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전지이용 전력저장장치 기술개발 (A Study on the Development of Battery Energy Storage System)

  • 황용하;이근섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.905-907
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    • 1993
  • Demand for electricity is increasing annually. Especially, the daytime demand grawth shows higher than any other time period. So the big difference between maximum and minimum electrical demand becomes another important problem to be solved. The Battery Energy Storage System is chosen as one of the solutions among the sevral methods. The purpose of utilization of Battery Energy Storage System is to improve the daily load factor. Also, Battery Energy Storage System may be used for the load levelling or the load shifting as well as the spinning reserve. Up to now, only the pumped hydro power plant system has been operated on the commercial basis, but this system has so many constraints such as site, environmental effects, construction period, ect. Being considered current electrical power situation the development of electric storage system is in need latly. Among the various electric storage systems, Battery Energy System is chosen with the top priority because it has sevral merits to cover such as the short construction period, the demand site installation, and the food environmental characteristics.

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건물(建物) 최대수요전력(最大需要電力)의 효율적(效率的) 운용(運用) 방안(方案) (A Study on the Efficient peak Demand Control Method in Office Buildings)

  • 김세동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.1088-1090
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    • 1993
  • This paper shows efficient peak demand control method in office buildings. With a rapid growth of national economics and living standard, electrical energy consumption markedly increased. Expecially, it is increased electrical energy comsumption in the office buildings and thus an energy conservation through efficient use of electricity became more important. From the data of electric equipment capacity and electric power consumption for 96 buildings, current levels of demand factor and a growth trend of peak loads by office buildings were surveyed and analyzed. In addition the efficient peak demand control method in office buildings were studied.

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최대수요전력 관리 장치의 최대수요전력 예측 방법에 관한 연구 (Method of Demand Forecasting for Demand Controller)

  • 권용훈;김호진;공인엽
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 춘계학술대회
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    • pp.833-836
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    • 2012
  • 최대수요전력 관리 장치는 현재 사용전력을 모니터링하여 예측 전력을 계산해 수용가에서 설정한 목표전력을 초과하지 않게 부하를 제어하는 장치이다. 부하의 제어는 예측된 최대수요전력이 목표전력을 초과할 경우 경보를 발생하고 부하를 차단하는 방식을 사용하기 때문에 최대수요전력에 대한 정확한 예측이 중요하다. 전력 변동이 심한 수용가에서는 기존의 예측 방법을 사용할 경우 최대수요전력 관리가 안정적이지 못하다는 단점이 있다. 본 논문에서는 기존의 최대수요전력 예측 방법 및 지수평활방법을 살펴보고 칼만 필터를 사용한 예측 방법을 제안한다.

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부조종사 자격증명(Multi-Crew Pilot License) 제도에 대한 국내 항공종사자 인식도 및 수요도 분석 (An Analysis of Domestic Airmen's Awareness and Demand for Multi-Crew Pilot License (MPL) Certification System)

  • 권문진;권한준;이장룡
    • 한국항공운항학회지
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    • 제30권3호
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    • pp.10-18
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    • 2022
  • A survey was conducted on the awareness and demand for the Multi-crew Pilot License (MPL) to prepare the legal institutional basis for the MPL certification system. A total of 288 airmen were asked questions about the awareness and demand of the MPL certification system, and factors affecting the establishment and participation of MPL training programs. The survey results show the understanding of the MPL certification system is significantly lower than that of the current pilot certification system. The demand for the MPL training program was found to be significant, trainees and low-skilled airmen was greater demand. The factor that has the greatest influence on the establishment and participation of the MPL training program was identified as employment connection (airline recruiting). It is expected that the result of this study will be used as basic data necessary for establishing MPL certification system policy.

Prediction of Global Industrial Water Demand using Machine Learning

  • Panda, Manas Ranjan;Kim, Yeonjoo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.156-156
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    • 2022
  • Explicitly spatially distributed and reliable data on industrial water demand is very much important for both policy makers and researchers in order to carry a region-specific analysis of water resources management. However, such type of data remains scarce particularly in underdeveloped and developing countries. Current research is limited in using different spatially available socio-economic, climate data and geographical data from different sources in accordance to predict industrial water demand at finer resolution. This study proposes a random forest regression (RFR) model to predict the industrial water demand at 0.50× 0.50 spatial resolution by combining various features extracted from multiple data sources. The dataset used here include National Polar-orbiting Partnership (NPP)/Visible Infrared Imaging Radiometer Suite (VIIRS) night-time light (NTL), Global Power Plant database, AQUASTAT country-wise industrial water use data, Elevation data, Gross Domestic Product (GDP), Road density, Crop land, Population, Precipitation, Temperature, and Aridity. Compared with traditional regression algorithms, RF shows the advantages of high prediction accuracy, not requiring assumptions of a prior probability distribution, and the capacity to analyses variable importance. The final RF model was fitted using the parameter settings of ntree = 300 and mtry = 2. As a result, determinate coefficients value of 0.547 is achieved. The variable importance of the independent variables e.g. night light data, elevation data, GDP and population data used in the training purpose of RF model plays the major role in predicting the industrial water demand.

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연안해운 선원인력 수요예측에 관한 연구 (A Study on the Demand Estimation of the Crew in Domestic Coastal Shipping Industry)

  • 박성진;배후석;신용존
    • 한국항해항만학회지
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    • 제36권3호
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    • pp.205-213
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    • 2012
  • 본 논문은 내항상선 선원의 수급 안정화를 기하여 연안해운의 발전을 도모하기 위하여 구체적으로 내항상선 선원의 수급실태의 분석을 통해 향후 내항상선 선원의 수요 전망을 예측하고자 하는 것이다. 연안 해운기업의 경쟁력 강화에 있어서 선원수급과 선원인력양성의 필요성을 인지하고, 특히 인력수요예측의 정밀성을 높이고 지속적이고 피드백이 가능한 예측 프로세스를 모색하는 것은 현재 연안해운기업의 열악한 선원인력관리의 어려움을 극복하기 위한 단초로서 현재 시의적절한 연구주제가 될 것이다. 향후 내항상선 선원의 수요부문에서 선박 척수의 변화에 따른 시뮬레이션 결과, 증가율 기준을 0.1%~1% 폭의 수준을 상정할 경우 7,879~8,258명으로 예측되었다. 이는 2009년 현재 7,831명 수준에서 매년 약 20~430명의 추가 인력이 투입되어야 함을 의미한다. 일반적으로 5년 내지 10년 단위로 단속적으로 예측치를 제시하는 방법은 예측의 사후추적이 부실한 관계로 예측정확도가 떨어지기 쉬운 점을 선행연구 검토 부분에서 확인하였으며, 본 연구와 같이 현황자료를 기초로 예측치와 실제치의 차이에 대한 피드백을 위해 매년 평가를 실행하고 그 결과를 차기년도 예측에 반영하는 접근방법을 도입한다면, 선원인력의 수급에 대한 예측정확도를 높일 수 있을 것이다.

수산물 수급통계 실태 및 개선과제 (Current Status and Improvement of the Fisheries Supply and Demand Statistics)

  • 이헌동;김대영
    • 수산경영론집
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    • 제48권2호
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    • pp.19-32
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    • 2017
  • The purpose of this study is to identify problems and suggest improvements of estimating procedures and item of fisheries supply-demand statistics served as a basis for the fisheries supply-demand policies. Korea Rural Economic Institute(KREI) and Ministry of Oceans and Fisheries(MOF) respectively publish the fisheries supply-demand statistics. But the reliability of data is low as the statistics of these two organizations are limited and show discrepancy in the numbers. It is therefore difficult to use them as the basic data for policies. Also, an accurate data aggregation is difficult due to following problems in the items of statistics. 1) Problems in estimating route sales and non-route sales of production, 2) adequacy of fishery product yield rate compared to raw material in the fisheries import/export sector, 3) selection of target companies for understand stocks and survey scope of fish species, 4) applying'0'to non-edible product demand etc. In order to develop the fisheries industry as a future growth industry, it is necessary to establish the accurate fisheries supply-demand policy as the instability of fisheries supply and demand is increasing. To do this, statistical reliability has to be improved. The improvements proposed in this study should be implemented considering urgency. First of all, an exhaustive analysis of stock statistics and conversion rates of raw material yield in the fisheries import/export sector should be conducted. In the medium term and the long term, transferring production statistics to MOF and surveys on the use demand of non-food product and the level of reduced and discarded seafood products should be carried out in consecutive order.

PDA(Patron-Driven Acquisitions) 방식 전자책 수서 모형에 관한 연구 (Study on eBook Acquisition Model based on Patron-Driven Acquisitions)

  • 조재인
    • 한국비블리아학회지
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    • 제26권4호
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    • pp.105-121
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    • 2015
  • 이용자의 수요를 표현하는 트리거가 누적되어 임계치에 다다를 때 사서의 개입없이 자동으로 전자책이 구입되는 PDA 모델은 이용자의 수요에 부합하는 장서를 구성하면서도 도서관의 수서 예산을 가장 효과적으로 지출할 수 있는 새로운 장서 개발 방법론이다. 본 연구는 우리에게 아직 생소한 PDA의 개념, 작동 원리, 운영 현황 등을 살펴보고, 컨소시엄 기반의 한국 대학도서관 해외 전자책 수서 모형에 적용할 수 있는 방안을 모색해 보았다. 한국에서는 다양한 해외 전자책 수서 모형이 적용되고 있으나, 최종 이용자의 수요에 기반한 PDA 일반 모델이나 증거기반선정 모델을 컨소시엄 단위로 응용함으로써 비용 효율성과 이용 가치 제고에 기여할 수 있을 것이다.