• 제목/요약/키워드: Methods of Forecasting

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A Taxonomy of Manpower Forecasting and Planning

  • Song, Moon-Ho
    • 한국국방경영분석학회지
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    • 제17권1호
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    • pp.130-145
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    • 1991
  • The literature has recorded many models dealing with manpower forecasting and planning. The approaches used by the various authors are clearly disparate. This paper presents a taxonomy for manpower planning and forecasting methodologies and classifies the landmark developments in this field. The taxonomical schema is then applied to unify the models in consideration of the methods and the decision factors used for forecasting and/or planning. The taxonomy allows for the most complex model structure containing all the factors considered germane in the existing literature.

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투자와 수출 및 환율의 고용에 대한 의사결정 나무, 랜덤 포레스트와 그래디언트 부스팅 머신러닝 모형 예측 (Investment, Export, and Exchange Rate on Prediction of Employment with Decision Tree, Random Forest, and Gradient Boosting Machine Learning Models)

  • 이재득
    • 무역학회지
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    • 제46권2호
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    • pp.281-299
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    • 2021
  • This paper analyzes the feasibility of using machine learning methods to forecast the employment. The machine learning methods, such as decision tree, artificial neural network, and ensemble models such as random forest and gradient boosting regression tree were used to forecast the employment in Busan regional economy. The following were the main findings of the comparison of their predictive abilities. First, the forecasting power of machine learning methods can predict the employment well. Second, the forecasting values for the employment by decision tree models appeared somewhat differently according to the depth of decision trees. Third, the predictive power of artificial neural network model, however, does not show the high predictive power. Fourth, the ensemble models such as random forest and gradient boosting regression tree model show the higher predictive power. Thus, since the machine learning method can accurately predict the employment, we need to improve the accuracy of forecasting employment with the use of machine learning methods.

개입 ARIMA 모형을 이용한 KTX 수요예측 (Forecasting the KTX Passenger Demand with Intervention ARIMA Model)

  • 김관형;김한수;이성덕;이현기;윤경만
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1715-1721
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    • 2011
  • For an efficient railroad operations the demand forecasting is required. Time series models can quickly forecast the future demand with fewer data. As well as the accuracy of forecasting is excellent compared to other methods. In this study is proposed the intervention ARIMA model for forecasting methods of KTX passenger demand. The intervention ARIMA model may reflect the intervention such as the Kyongbu high-speed rail project second phase. The simple seasonal ARIMA model is predicted to overestimate the KTX passenger demand. However, intervention ARIMA model is predicted the reasonable results. The KTX passenger demands were predicted to be a week units separated by the weekday and weekend.

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단기 물 수요예측 시뮬레이터 개발과 예측 알고리즘 성능평가 (Development of Water Demand Forecasting Simulator and Performance Evaluation)

  • 신강욱;김주환;양재린;홍성택
    • 상하수도학회지
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    • 제25권4호
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    • pp.581-589
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    • 2011
  • Generally, treated water or raw water is transported into storage reservoirs which are receiving facilities of local governments from multi-regional water supply systems. A water supply control and operation center is operated not only to manage the water facilities more economically and efficiently but also to mitigate the shortage of water resources due to the increase in water consumption. To achieve the goal, important information such as the flow-rate in the systems, water levels of storage reservoirs or tanks, and pump-operation schedule should be considered based on the resonable water demand forecasting. However, it is difficult to acquire the pattern of water demand used in local government, since the operating information is not shared between multi-regional and local water systems. The pattern of water demand is irregular and unpredictable. Also, additional changes such as an abrupt accident and frequent changes of electric power rates could occur. Consequently, it is not easy to forecast accurate water demands. Therefore, it is necessary to introduce a short-term water demands forecasting and to develop an application of the forecasting models. In this study, the forecasting simulator for water demand is developed based on mathematical and neural network methods as linear and non-linear models to implement the optimal water demands forecasting. It is shown that MLP(Multi-Layered Perceptron) and ANFIS(Adaptive Neuro-Fuzzy Inference System) can be applied to obtain better forecasting results in multi-regional water supply systems with a large scale and local water supply systems with small or medium scale than conventional methods, respectively.

SSA를 이용한 일 단위 물수요량 단기 예측에 관한 연구 (A Study of Short Term Forecasting of Daily Water Demand Using SSA)

  • 권현한;문영일
    • 상하수도학회지
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    • 제18권6호
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    • pp.758-769
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    • 2004
  • The trends and seasonalities of most time series have a large variability. The result of the Singular Spectrum Analysis(SSA) processing is a decomposition of the time series into several components, which can often be identified as trends, seasonalities and other oscillatory series, or noise components. Generally, forecasting by the SSA method should be applied to time series governed (may be approximately) by linear recurrent formulae(LRF). This study examined forecasting ability of SSA-LRF model. These methods are applied to daily water demand data. These models indicate that most cases have good ability of forecasting to some extent by considering statistical and visual assessment, in particular forecasting validity shows good results during 15 days.

신경회로망을 이용한 단기전력부하 예측용 시스템 개발 (Development of Electric Load Forecasting System Using Neural Network)

  • 김형수;문경준;황기현;박준호;이화석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1522-1522
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    • 1999
  • This paper proposes the methods of short-term load forecasting using Kohonen neural networks and back-propagation neural networks. Historical load data is divided into 5 patterns for the each seasonal data using Kohonen neural networks and using these results, load forecasting neural network is used for next day hourly load forecasting. Normal days and holidays are forecasted. For load forecasting in summer, max-, and min-temperature data are included in neural networks for a better forecasting accuracy. To show the possibility of the proposed method, it was tested with hourly load data of Korea Electric Power Corporation. (1993-1997)

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Long-Term Forecasting by Wavelet-Based Filter Bank Selections and Its Application

  • Lee, Jeong-Ran;Lee, You-Lim;Oh, Hee-Seok
    • 응용통계연구
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    • 제23권2호
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    • pp.249-261
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    • 2010
  • Long-term forecasting of seasonal time series is critical in many applications such as planning business strategies and resolving possible problems of a business company. Unlike the traditional approach that depends solely on dynamic models, Li and Hinich (2002) introduced a combination of stochastic dynamic modeling with filter bank approach for forecasting seasonal patterns using highly coherent(High-C) waveforms. We modify the filter selection and forecasting procedure on wavelet domain to be more feasible and compare the resulting predictor with one that obtained from the wavelet variance estimation method. An improvement over other seasonal pattern extraction and forecasting methods based on such as wavelet scalogram, Holt-Winters, and seasonal autoregressive integrated moving average(SARIMA) is shown in terms of the prediction error. The performance of the proposed method is illustrated by a simulation study and an application to the real stock price data.

Spatio-temporal Load Forecasting Considering Aggregation Features of Electricity Cells and Uncertainties in Input Variables

  • Zhao, Teng;Zhang, Yan;Chen, Haibo
    • Journal of Electrical Engineering and Technology
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    • 제13권1호
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    • pp.38-50
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    • 2018
  • Spatio-temporal load forecasting (STLF) is a foundation for building the prediction-based power map, which could be a useful tool for the visualization and tendency assessment of urban energy application. Constructing one point-forecasting model for each electricity cell in the geographic space is possible; however, it is unadvisable and insufficient, considering the aggregation features of electricity cells and uncertainties in input variables. This paper presents a new STLF method, with a data-driven framework consisting of 3 subroutines: multi-level clustering of cells considering their aggregation features, load regression for each category of cells based on SLS-SVRNs (sparse least squares support vector regression networks), and interval forecasting of spatio-temporal load with sampled blind number. Take some area in Pudong, Shanghai as the region of study. Results of multi-level clustering show that electricity cells in the same category are clustered in geographic space to some extent, which reveals the spatial aggregation feature of cells. For cellular load regression, a comparison has been made with 3 other forecasting methods, indicating the higher accuracy of the proposed method in point-forecasting of spatio-temporal load. Furthermore, results of interval load forecasting demonstrate that the proposed prediction-interval construction method can effectively convey the uncertainties in input variables.

Comparison of forecasting performance of time series models for the wholesale price of dried red peppers: focused on ARX and EGARCH

  • Lee, Hyungyoug;Hong, Seungjee;Yeo, Minsu
    • 농업과학연구
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    • 제45권4호
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    • pp.859-870
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    • 2018
  • Dried red peppers are a staple agricultural product used in Korean cuisine and as such, are an important aspect of agricultural producers' income. Correctly forecasting both their supply and demand situations and price is very important in terms of the producers' income and consumer price stability. The primary objective of this study was to compare the performance of time series forecasting models for dried red peppers in Korea. In this study, three models (an autoregressive model with exogenous variables [ARX], AR-exponential generalized autoregressive conditional heteroscedasticity [EGARCH], and ARX-EGARCH) are presented for forecasting the wholesale price of dried red peppers. As a result of the analysis, it was shown that the ARX model and ARX-EGARCH model, each of which adopt both the rolling window and the adding approach and use the agricultural cooperatives price as the exogenous variable, showed a better forecasting performance compared to the autoregressive model (AR)-EGARCH model. Based on the estimation methods and results, there was no significant difference in the accuracy of the estimation between the rolling window and adding approach. In the case of dried red peppers, there is limitation in building the price forecasting models with a market-structured approach. In this regard, estimating a forecasting model using only price data and identifying the forecast performance can be expected to complement the current pricing forecast model which relies on market shipments.

국내 패션 시스템에서 패션 트렌드 정보 예측의 영향력 (Influence of Fashion Trend Forecasting on Korean Fashion System)

  • 정다운;김성은;하지수
    • 한국의류학회지
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    • 제46권6호
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    • pp.963-986
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    • 2022
  • This article surveys the fashion forecasting industry in Korean domestic markets. With the rise of new media and devices with high technology, the paradigm of fashion trends forecasting systems has dramatically changed. New perspectives of trend forecasting are required to understand the trend flow and consumer behavior of the MZ generation. The research questions are as follows: 1) Major trend forecasting companies studied the development of their strategies and new forecasting methods. 2) The consumers' needs in the domestic market were analyzed. The influence of the trend companies' forecasting on the market was investigated. The results are as follows: 1) International trend forecasting significantly affected the domestic market. The concordance rate between consumers' online searches about fashion trends was approximately 70.14%. The match rate by category is as follows: The highest rate, 85.06% is from pattern and print, color is 83.92%, the item is 80.39%, and style is 54.32%. 2) Specialized information such as the Pantone color chart is being widely consumed, leading to a trend among the masses. 3) The Korean-specific socio-cultural background has an impact on domestic trends.