• Title/Summary/Keyword: supply and demand forecasting

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Forecasting Daily Demand of Domestic City Gas with Selective Sampling (선별적 샘플링을 이용한 국내 도시가스 일별 수요예측 절차 개발)

  • Lee, Geun-Cheol;Han, Jung-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6860-6868
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    • 2015
  • In this study, we consider a problem of forecasting daily city gas demand of Korea. Forecasting daily gas demand is a daily routine for gas provider, and gas demand needs to be forecasted accurately in order to guarantee secure gas supply. In this study, we analyze the time series of city gas demand in several ways. Data analysis shows that primary factors affecting the city gas demand include the demand of previous day, temperature, day of week, and so on. Incorporating these factors, we developed a multiple linear regression model. Also, we devised a sampling procedure that selectively collects the past data considering the characteristics of the city gas demand. Test results on real data exhibit that the MAPE (Mean Absolute Percentage Error) obtained by the proposed method is about 2.22%, which amounts to 7% of the relative improvement ratio when compared with the existing method in the literature.

A New Bootstrap Simulation Method for Intermittent Demand Forecasting (간헐적 수요예측을 위한 부트스트랩 시뮬레이션 방법론 개발)

  • Park, Jinsoo;Kim, Yun Bae;Lee, Ha Neul;Jung, Gisun
    • Journal of the Korea Society for Simulation
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    • v.23 no.3
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    • pp.19-25
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    • 2014
  • Demand forecasting is the basis of management activities including marketing strategy. Especially, the demand of a part is remarkably important in supply chain management (SCM). In the fields of various industries, the part demand usually has the intermittent characteristic. The intermittent characteristic implies a phenomenon that there frequently occurs zero demands. In the intermittent demands, non-zero demands have large variance and their appearances also have stochastic nature. Accordingly, in the intermittent demand forecasting, it is inappropriate to apply the traditional time series models and/or cause-effect methods such as linear regression; they cannot describe the behaviors of intermittent demand. Markov bootstrap method was developed to forecast the intermittent demand. It assumes that first-order autocorrelation and independence of lead time demands. To release the assumption of independent lead time demands, this paper proposes a modified bootstrap method. The method produces the pseudo data having the characteristics of historical data approximately. A numerical example for real data will be provided as a case study.

The Rearch Of Method in the Appropriate number of Demand and Supply of OMD (한의사인력(韓醫師人力) 공급(供給)의 적정화방안(適定化方案) 연구(硏究))

  • Lee, Jong-Soo
    • The Journal of Korean Medicine
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    • v.19 no.1
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    • pp.299-326
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    • 1998
  • 1. Comparison of demand and supply A. Assumption of estimation of demand and supply we will briefly assumptions used for presumption once more before comparing the result of estimation of demand and supply examined previously 1) supply - The average applying rate for state. examination of graduate: ${\alpha}$=1.03109 - The ratio of successful applicants of state examinations: ${\beta}$=0.97091 - Mortality classified by age : presumed data of the Bureau of statistics - Emigrating rate: 0 % - Time of retire: unconsidered - An army doctor number: unconsidered and regard number of employed oriental medicine doctor. - Standard of 1995 : The number of survival oriental medicine doctor is 8195. the number of employed oriental medicine doctor is 7419. 2) demand - derivated demand method Daily the average amount of medical treatment: according to medical insurance federation data. there is 16 or 6 non allowance patient, we consider amount of medical treatment as 22 persons in practical because 21.94 persons (founded practical examination) are converted to allowance in comming demand. Daily the proper amount of medical treatment: 7 hours form -35 persons 5 hours 30 minutes form -28 persons. Yearly medical treatment days: 229 days. 255 days. 269 days . Increasing rate of visiting hospital days: -1996 year. 1997 year. 1998 year- . Rate of applying insurance: yearly average 71.51% (among the investigated patient) B. Comparison of total sum result 1) supply (provision) Table Ⅳ-1 below shows the estimation of the oriental medicine doctor in the future.

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  • Short-term Load Forecasting of Using Data refine for Temperature Characteristics at Jeju Island (온도특성에 대한 데이터 정제를 이용한 제주도의 단기 전력수요 예측)

    • Kim, Ki-Su;Song, Kyung-Bin
      • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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      • 2008.10a
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      • pp.225-228
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      • 2008
    • The electricity supply and demand to be stable to a system link increase of the variance power supply and operation are requested in jeju Island electricity system. A short-term Load forecasting which uses the characteristic of the Load is essential consequently. We use the interrelationship of the electricity Load and change of a summertime temperature and data refining in the paper. We presented a short-term Load forecasting algorithm of jeju Island and used the correlation coefficient to the criteria of the refining. We used each temperature area data to be refined and forecasted a short-term Load to an exponential smoothing method.

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    Mobile Traffic Trends (모바일 트래픽 동향)

    • Jahng, J.H.;Park, S.K.
      • Electronics and Telecommunications Trends
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      • v.34 no.3
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      • pp.106-113
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      • 2019
    • Mobile traffic is one of the most important indexes of the growth of the mobile communications market, and it has a close relationship with subscribers' service usage patterns, frequency demand and supply, network management, and information communication policy. The purpose of this paper is to understand mobile data usage in Korea and to suggest the optimal steps for establishing the frequency supply and demand system by researching the traffic trends that reflect the characteristics of radio resources in the mobile communications field. To achieve this goal, attempts were made to increase the possibility of policy use by analyzing and forecasting mobile traffic trends, and to improve the accuracy of the research through the verification of the existing prediction results. The paper ends with a discussion of the necessity of a frequency management system based on data science.

    Development of Heat Demand Forecasting Model using Deep Learning (딥러닝을 이용한 열 수요예측 모델 개발)

    • Seo, Han-Seok;Shin, KwangSup
      • The Journal of Bigdata
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      • v.3 no.2
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      • pp.59-70
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      • 2018
    • In order to provide stable district heat supplying service to the certain limited residential area, it is the most important to forecast the short-term future demand more accurately and produce and supply heat in efficient way. However, it is very difficult to develop a universal heat demand forecasting model that can be applied to general situations because the factors affecting the heat consumption are very diverse and the consumption patterns are changed according to individual consumers and regional characteristics. In particular, considering all of the various variables that can affect heat demand does not help improve performance in terms of accuracy and versatility. Therefore, this study aims to develop a demand forecasting model using deep learning based on only limited information that can be acquired in real time. A demand forecasting model was developed by learning the artificial neural network of the Tensorflow using past data consisting only of the outdoor temperature of the area and date as input variables. The performance of the proposed model was evaluated by comparing the accuracy of demand predicted with the previous regression model. The proposed heat demand forecasting model in this research showed that it is possible to enhance the accuracy using only limited variables which can be secured in real time. For the demand forecasting in a certain region, the proposed model can be customized by adding some features which can reflect the regional characteristics.

    Supramax Bulk Carrier Market Forecasting with Technical Indicators and Neural Networks

    • Lim, Sang-Seop;Yun, Hee-Sung
      • Journal of Navigation and Port Research
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      • v.42 no.5
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      • pp.341-346
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      • 2018
    • Supramax bulk carriers cover a wide range of ocean transportation requirements, from major to minor bulk cargoes. Market forecasting for this segment has posed a challenge to researchers, due to complexity involved, on the demand side of the forecasting model. This paper addresses this issue by using technical indicators as input features, instead of complicated supply-demand variables. Artificial neural networks (ANN), one of the most popular machine-learning tools, were used to replace classical time-series models. Results revealed that ANN outperformed the benchmark binomial logistic regression model, and predicted direction of the spot market with more than 70% accuracy. Results obtained in this paper, can enable chartering desks to make better short-term chartering decisions.

    A Study on Demand Forecasting Model of Domestic Rare Metal Using VECM model (VECM모형을 이용한 국내 희유금속의 수요예측모형)

    • Kim, Hong-Min;Chung, Byung-Hee
      • Journal of Korean Society for Quality Management
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      • v.36 no.4
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      • pp.93-101
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      • 2008
    • The rare metals, used for semiconductors, PDP-LCS and other specialized metal areas necessarily, has been playing a key role for the Korean economic development. Rare metals are influenced by exogenous variables, such as production quantity, price and supplied areas. Nowadays the supply base of rare metals is threatened by the sudden increase in price. For the stable supply of rare metals, a rational demand outlook is needed. In this study, focusing on the domestic demand for chromium, the uncertainty and probability materializing from demand and price is analyzed, further, a demand forecast model, which takes into account various exogenous variables, is suggested, differing from the previously static model. Also, through the OOS(out-of-sampling) method, comparing to the preexistence ARIMA model, ARMAX model, multiple regression analysis model and ECM(Error Correction Mode) model, we will verify the superiority of suggested model in this study.

    Electricity forecasting model using specific time zone (특정 시간대 전력수요예측 시계열모형)

    • Shin, YiRe;Yoon, Sanghoo
      • Journal of the Korean Data and Information Science Society
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      • v.27 no.2
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      • pp.275-284
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      • 2016
    • Accurate electricity demand forecasts is essential in reducing energy spend and preventing imbalance of the power supply. In forcasting electricity demand, we considered double seasonal Holt-Winters model and TBATS model with sliding window. We selected a specific time zone as the reference line of daily electric demand because it is least likely to be influenced by external factors. The forecasting performance have been evaluated in terms of RMSE and MAPE criteria. We used the observations ranging January 4, 2009 to December 31 for testing data. For validation data, the records has been used between January 1, 2012 and December 29, 2012.

    Development of a System Dynamics Model for Forecasting the Automobile Market (시스템다이내믹스 기법을 활용한 차급별 월간 자동차 수요 예측 모델 개발)

    • 곽상만;김기찬;안수웅;장원혁;홍정석
      • Korean System Dynamics Review
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      • v.3 no.1
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      • pp.79-104
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      • 2002
    • A system dynamics project is going on for forecasting automobile market in Korea. The project is made up of three stages, and the first stage has been wrapped up. As the first attempt, most efforts have been focused on the sound foundation rather than the exact forecast. The model consists of three sectors; the supply sector, the demand sector, and the population sector. The supply sector is a simple stock and flow diagrams representing the supply capacities of all automobile types. The major effort is made on the demand sector and the population sector. The demands are divided into three categories; replacement demands, new demands, and additional demands. The model applies “one car per person" concept, and assumes there will be no additional demands for a while. The replacement demands are calculated based on a simple stock and flow diagram. The new demands are calculated via Bass models; each bass model represents a diffusion for each age group. The population is divided into 101 age groups (age 0 to age 100). The model has been calibrated with past 10 year data (1990 - 1999), and tested for the next two years (2000-2001). The results ware acceptable, although a fine tuning is required. Now the second stage is going on, and most of efforts are made how to incorporate the economic and cultural factors.

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