tei@i methodology and its applications shouyang wang academy of mathematics and systems science...
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TEI@I Methodologyand its Applications
Shouyang WangShouyang Wang
Academy of Mathematics and Systems Science
Chinese Academy of Sciences
Center for Forecasting Science, Chinese Academy of Sciences
Email: [email protected] and [email protected]
http://madis1.iss.ac.cn and www.amss.ac.cn
TEI@I—A New TEI@I—A New Methodology Methodology
forforCrude Oil Price ForecastingCrude Oil Price Forecasting
Introduction I
Importance of oil price forecastingImportance of oil price forecasting: The role of oil in the world economy becomes more and more significant because nearly two-thirds of the world’s energy consumption comes from the crude oil and natural gas. For example, worldwide consumption of crude oil exceeds $500
billion, roughly 10% of the USA’s GDP. crude oil is also the world’s most actively traded
commodity, accounting for about 10% of total world trade.
Introduction II
Determination of oil price Determination of oil price : Basically, crude oil price is determined by its supply and demand, and is strongly influenced by many irregular future events like the weather, stock levels, GDP growth, political aspects and even people’s expectation.
The above facts lead to a strongly fluctuating and interacting market whose fundamental mechanism governing the complex dynamics is not well understood.
Furthermore, because sharp oil price movements are likely to disturb aggregate economic activity, researchers have shown considerable interests for volatile oil prices.
Therefore, forecasting oil prices is an important and very hard topic due to its intrinsic difficulty and practical applications.
Introduction III
Main literature about oil price forecasting: Main literature about oil price forecasting: Watkins, G.C., Plourde, A.: How volatile are crude oil prices? OPEC
Review, 18(4), (1994) 220-245. Hagen, R.: How is the international price of a particular crude determining?
OPEC Review, 18 (1), (1994) 145-158 Stevens, P.: The determination of oil prices 1945-1995. Energy Policy,
23(10), (1995) 861-870 Huntington, H.G.: Oil price forecasting in the 1980s: what went wrong? The
Energy Journal, 15(2), (1994) 1-22. Abramson, B., Finizza, A.: Probabilistic forecasts from probabilistic models:
a case study in the oil market. International Journal of Forecasting, 11(1), (1995) 63-72
Morana, C.: A semiparametric approach to short-term oil price forecasting. Energy Economics, 23(3), (2001) 325-338
Introduction IV
Evaluation about literature:Evaluation about literature: There are only very limited number of related papers on oil price
forecasting. The literature focuses on the oil price volatility analysis. The literature focuses only on oil price determination within the
framework of supply and demand.
It is, therefore, very necessary to introduce It is, therefore, very necessary to introduce
new method for crude oil price forecasting.new method for crude oil price forecasting.
TEI@I Introduction (A)TEI@I Introduction (A)
In view of difficulty and complexity of crude oil price
forecasting, a new methodology named TEI@I is
proposed in this study to “integrate” systematically “text
mining”, “econometrics” and “intelligent techniques” and
a novel integrated forecasting approach with error
correction and judgmental adjustment within the
framework of the TEI@I methodology is presented for
improving prediction performance. .
TEI@I Introduction (B)TEI@I Introduction (B)
Here the name “TEI@I” is based on “text
mining” + “econometrics” + “intelligence
(intelligent algorithms)” @ “integration”. Using
“@” to replace “+” is to emphasize the
functional of integrations. The general
framework structure is shown in the following
figure.
Man-machine interface (MMI) module
The man-machine interface (MMI) is a graphical window through which users can exchange information within the framework of TEI@I.
it handles all input/output between users and the TEI@I system.
it can be considered as open platform communicating with users and interacting with other components of the TEI@I system.
Web-based text mining module
Crude oil market is an unstable market with high volatility and oil price is often affected by many related factors.
In order to improve forecasting accuracy, these related factors should be taken into consideration in forecasting.
Web-based text mining is used to explore the related factors.
In this study, the main goal of web-based text mining module is to collect related information affecting oil price variability from Internet and to provide the collected useful information to the rule-based expert
system forecasting module.
Rule-based expert system (RES) module
Expert system module is used to transform the irregular events into valuable adjusted information.
That is, rule-based expert system is used to extract some rules to judge oil price abnormal variability by summarizing the relationships between oil price fluctuation and key factors affecting oil price volatility.
See the paper for a detailed discussion.
Econometrical forecasting moduleEconometrical forecasting module
It includes a large number of modeling techniques and models, such as autoregressive integrated moving average (ARIMA) model, vector auto-regression (VAR) model, generalized moment method (GMM), etc.
Autoregressive integrated moving average (ARIMA) model is used here.
ARIMA is used to model the linear pattern of oil price time series, while nonlinear component is modeled by artificial neural network (ANN).
ANN-based time series forecasting module
The ANN used in this study is a three-layer back-
propagation neural network (BPNN) incorporating
the Levenberg- Marquardt algorithm for training.
For an univariate time-series forecasting problem,
the inputs of the network are the past lagged
observations of the data series and the outputs are
the future values.
BPNN time-series forecasting model performs a
nonlinear mapping. That is, ),,,( 11 ptttt yyyfy
Bases and bases management module
The other modules of the TEI@I system have a strong connection with this module.
For example, ANN-based forecasting module utilizes MB and DB, while the rule-based expert system mainly used the KB and DB.
To summarize, the TEI@I system framework is developed through an integration of the web-based text mining, rule-based expert system and ANN-based time series forecasting techniques.
In this framework, econometrical models (e.g., autoregressive integrated moving average (ARIMA)) are used to model the linear components of crude oil price time series (i.e., the main trends).
Nonlinear components of crude oil price time series (i.e., error term) are modeled by a neural network (NN) model.
the effects of irregular and infrequent future events on crude oil price are explored by web-based text mining (WTM) and rule-based expert systems (RES) techniques.
MMI and BBM are the auxiliary modules for constructing the integrated TEI@I system.
Remarks
The nonlinear integrated forecasting approach
Within the framework of TEI@I methodology, a novel nonlinear integrated forecasting approach is proposed to improve oil price forecasting performance.
The flow chart of the nonlinear integrated forecasting approach is shown in the following.
A simulation study
Data and settingsThe crude oil price data used in this study are
monthly spot prices of West Texas Intermediate (WTI) crude oil, covered the period from January 1970 to December 2003 with a total of n = 408 observations. For the purpose of this study, the first 360 observations are used in-sample data (including 72 validation data) as training and validating sets, while the reminders are used as testing ones.
The forecasting results of crude oil price (Jan. 2000 - Dec. 2003)
Simulation Results (I)
Methods CriteriaFull period
(2000-2003)Sub-period I
(2000)Sub-period II
(2001)
Sub-period III
(2002)
Sub-period IV
(2003)
ARIMARMSE 2.3392 3.0032 1.7495 1.9037 2.4868
Dstat (%) 54.17 41.67 50.00 58.33 66.67
ANNRMSE 2.3336 2.7304 1.4847 1.8531 2.6436
Dstat (%) 70.83 75.00 75.00 66.67 66.67
Simple integration
RMSE 2.0350 3.2653 1.0435 0.9729 1.9665
Dstat (%) 85.42 75.00 91.67 100.00 75.00
Nonlinear integration
RMSE 1.0549 1.7205 0.6834 0.8333 0.5746
Dstat (%) 95.83 100.00 83.33 100.00 100.00
Simulation Results (II)
Methods
Full period(2000-2003)
Sub-period I(2000)
Sub-period II(2001)
Sub-period III
(2002)
Sub-period IV
(2003)
Simple integration
70.83% 41.67% 83.33% 91.67% 66.67%
Nonlinear integration
85.42% 83.33% 75.00% 83.33% 100.0%
The comparison of hit ratios between nonlinear integration approach and simple integration approach
2003年初对上半年出口预测与实际比较
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Jan-03 Feb-03 Mar-03 Apr-03 May-03 Jun-03
预测值 实际值
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2003. 7 2003. 8 2003. 9 2003. 1 2003. 11 2003. 12
预测值(亿美元) 实际值(亿美元)
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2004. 1 2004. 2 2004. 3 2004. 4 2004. 5 2004. 6 2004. 7 2004. 8 2004. 9
预测值(亿美元) 实际值(亿美元)
2004年前三季度出口预测与实际值比较
2003年下半年出口预测与实际值比较
全国粮食产量预测
第一、预测提前期为半年以上。为政府有关部门安排粮食消费、储存和进出口留下了充足的时间; (国际上谷物产量预测提前期通常为 2个月左右)。第二、预测各年度的粮食丰、平、歉方向全部正确; (目前国际上发达国家预测谷物产量丰、平、歉方向为大部分正确)第三、预测平均误差为产量的 1.26% 。
( 目前国际上发达国家预测误差为 5-10% ,如美国农业部提前 2个月进行预测的误差为 8-9% ,法国最近 6年的平均预测误差为 9%)
Conclusions
1. A new TEI@I methodology integrating web-based text mining & rule-based expert system techniques, econometrical techniques with intelligent forecasting techniques is presented. Based on the TEI@I methodology, a novel nonlinear integrated forecasting approach is proposed.
2. The methodology .has been successfully applied to solve a number of hard forecasting problems in practice and the results are very encouraging. Our research supports some governmental departments for their policy making.
Conclusions
3. The methodology can be used to solve many other complicated practical problems, not only in the field of forecasting.
4 However, TEI@I methodology needs more research, including on how to make a good integration for the three components.
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