A novel text-based framework for forecasting agricultural futures using massive online news headlines

The agricultural futures prices are generally considered difficult to forecast because the causes of fluctuations are incredibly complicated. We propose a text-based forecasting framework, which can effectively identify and quantify factors affecting agricultural futures based on massive online news headlines. A comprehensive list of influential factors can be formed using a text mining method called topic modeling. A new sentiment-analysis-based way is designed to quantify the factors such as the weather and policies that are important yet difficult to quantify. The proposed framework is empirically tested at forecasting soybean futures prices in the Chinese market. Testing was based on 9715 online news headlines from July 19, 2012 to July 9, 2018. The results show that the identified influential factors and sentiment-based variables are effective, and the proposed framework performs significantly better in medium-term and long-term forecasting than the benchmark model.     

Daily retail demand forecasting using machine learning with emphasis on calendric special days

Demand forecasting is an important task for retailers as it is required for various operational decisions. One key challenge is to forecast demand on special days that are subject to vastly different demand patterns than on regular days. We present the case of a bakery chain with an emphasis on special calendar days, for which we address the problem of forecasting the daily demand for different product categories at the store level. Such forecasts are an input for production and ordering decisions. We treat the forecasting problem as a supervised machine learning task and provide an evaluation of different methods, including artificial neural networks and gradient-boosted decision trees. In particular, we outline and discuss the possibility of formulating a classification instead of a regression problem. An empirical comparison with established approaches reveals the superiority of machine learning methods, while classification-based approaches outperform regression-based approaches. We also found that machine learning methods not only provide more accurate forecasts but are also more suitable for applications in a large-scale demand forecasting scenario that often occurs in the retail industry.     

Prediction accuracy for reservation-based forecasting methods applied in Revenue Management

With a few notable exceptions, airlines and hospitality forecasting research has been focused so far on point predictions of customers’ bookings. However, Revenue Management decisions are subject to a much greater risk when based exclusively on point predictions. To overcome this drawback, we propose a stochastic framework that allows the construction of prediction intervals for reservation-based (pickup) forecasting methods, which are widely used in the industry. Moreover, we introduce an extension of the multiplicative pickup technique based on Generalized Linear Models. We test the proposed framework with real reservation data from a medium-sized hotel on Lake Maggiore (Italy) and we obtain more efficient prediction intervals relative to classical time series methods. Our approach can be useful to hotel revenue managers that wish to make more informed decisions, planning alternative pricing and room allocation strategies for a range of possible demand scenarios.     

基于灰色预测模型与季节指数的区域物流需求预测

针对灰色预测模型在区域物流中不能有效解决因季节变动而引起的物流需求变化的问题,引入季节指数的概念,构建基于灰色模型和季节指数的物流需求预测模型,并给出了相应的具体实施方案。最后以哈尔滨市物流需求统计数据为例,对所提方法进行了仿真分析,仿真结果表明了该方法的有效性和可行性。     

INTEGRATION OF RANDOM SAMPLE SELECTION,SUPPORT VECTOR MACHINES AND ENSEMBLES FOR FINANCIAL RISK FORECASTING WITH AN EMPIRICAL ANALYSIS ON THE NECESSITY OF FEATURE SELECTION

Financial risk forecasting (FRF) is an effective tool to help people forecast whether or not a company will fail in future. Among all techniques of FRF, the support vector machine (SVM) is the most newly developed, and one of the most accurate and effective techniques. This study is devoted to investigating an ensemble model of FRF by integrating bagging with an SVM to generate a data‐driven SVM ensemble. Bagging is used to produce diverse training datasets on which multiple SVM classifiers are trained to make FRF for a target company. Simple voting is employed to produce a final decision from the SVM model committee. The empirical study has two objectives. One is to verify whether the data‐driven SVM ensemble can produce a more dominating performance than the most frequently used techniques in the area of FRF, i.e. multivariate discriminant analysis, logistics regression and a single SVM. The other is to verify whether feature selection is necessary to help the SVM make more precise FRF, although the SVM can handle high‐dimensional data. The results indicate that the data‐driven SVM ensemble significantly improves the predictive ability of SVM‐based FRF. Meanwhile, feature selection can effectively help the SVM achieve better predictive performance, which means that use of feature selection is necessary in SVM‐based FRF. Copyright © 2012 John Wiley & Sons, Ltd.     

基于小波变换和贝叶斯证据推断框架下的LS—SVM短期风速预测

基于小波的多分辨率分析,针对风速序列拟周期性、非平稳性及非线性等特点,将风速序列按不同频率进行分解,对分解后的原始风速信号分别建立不同的预测模型;各个模型的最佳参数由贝叶斯证据3层推断得出,用以建立基于小波和贝叶斯证据推断框架下的最小二乘支持向量机（LS-SVM）回归短期风速预测模型。应用该模型对东北某风电场的风速进行了提前1h的预测,预测的平均绝对百分比误差为7．63％,提高了预测精度。预测结果表明：基于贝叶斯证据推断框架下的LS—SVM和小波分析相结合的短期风速预测模型是一种有效、可行的风速预测模型,可为风力发电功率的预测提供一定的理论支持。     

基于ARIMA-GRACH模型的现货电价预测

通过建立ARIMA预测模型对现货电价进行预测,并对ARIMA模型存在的异方差问题通过GARCH模型进行修正。实证算例中,采用北欧四国电力市场数据,与ARIMA和灰色GM（1,1）模型进行比较,表明ARIMA—GARCH模型的预测精度更高,预测误差更小。     

基于灰色系统理论的我国石油消费对外依存度预测

在分析石油消费对外依存度与各个产业比重的关联度的基础之上,选取关联度最大的第二产业比重建立GM(1,1)模型,引入二阶软化算子调整第二产业比重数列,然后在此基础上建立石油消费对外依存度和第二产业比重的GM(1,2)模型。结果表明,我国石油消费对外依存度以年均1.51%的速度增长,到2018年将达60%。依据石油消费对外依存度指标等级分值表可知,届时我国石油安全处于高度危险的水平,因此,针对如何降低石油消费对外依存度给出了三点建议。     

Putting the New Keynesian DSGE Model to the Real‐Time Forecasting Test

The paper compares the quality of real‐time forecasts from a standard medium‐scale New Keynesian dynamic stochastic general equilibrium (DSGE) model to those from the Survey of Professional Forecasters (SPF) and DSGE‐VARs. It is shown that the DSGE model is relatively successful in forecasting the U.S. economy. This is especially true for forecasts conditional on SPF nowcasts, in which case the forecasting power of the DSGE turns out to be similar or better than that of the SPF for all the variables and horizons. An important weakness of the benchmark DSGE model is the poor absolute performance of its point forecasts and rather badly calibrated forecast densities.     

A multivariate neural forecasting modeling for air transport – Preprocessed by decomposition: A Brazilian application

An artificial neural forecasting model is developed for air transport passenger analysis. It uses a preprocessing method that decomposes information to reveal relevant features from the data. It is found that neural processing outperforms the traditional econometric approach and offers generalization on time series behavior, even where there are only small samples.