基于WOA-LSTM的窄带通信网网络时延预测算法

为了给窄带通信网的链路选择及协议的智能切换提供实时参考,设计了 一种基于鲸鱼优化算法(WOA)和长短期记忆神经网络(LSTM)的窄带通信网网络时延预测算法.首先对实测数据样本进行标准化处理,以LSTM神经网络算法的均方根误差函数的倒数作为适应度函数;其次采用鲸鱼优化算法对LSTM神经网络的学习率、隐含层神经元个数进行优...     

Forecasting volatility of crude oil futures using a GARCH–RNN hybrid approach

Volatility is an important element for various financial instruments owing to its ability to measure the risk and reward value of a given financial asset. Owing to its importance, forecasting volatility has become a critical task in financial forecasting. In this paper, we propose a suite of hybrid models for forecasting volatility of crude oil under different forecasting horizons. Specifically, we combine the parameters of generalized autoregressive conditional heteroscedasticity (GARCH) and Glosten–Jagannathan–Runkle (GJR)-GARCH with long short-term memory (LSTM) to create three new forecasting models named GARCH–LSTM, GJR-LSTM, and GARCH-GJRGARCH LSTM in order to forecast crude oil volatility of West Texas Intermediate on different forecasting horizons and compare their performance with the classical volatility forecasting models. Specifically, we compare the performances against existing methodologies of forecasting volatility such as GARCH and found that the proposed hybrid models improve upon the forecasting accuracy of Crude Oil: West Texas Intermediate under various forecasting horizons and perform better than GARCH and GJR-GARCH, with GG–LSTM performing the best of the three proposed models at 7-, 14-, and 21-day-ahead forecasts in terms of heteroscedasticity-adjusted mean square error and heteroscedasticity-adjusted mean absolute error, with significance testing conducted through the model confidence set showing that GG–LSTM is a strong contender for forecasting crude oil volatility under different forecasting regimes and rolling-window schemes. The contribution of the paper is that it enhances the forecasting ability of crude oil futures volatility, which is essential for trading, hedging, and purposes of arbitrage, and that the proposed model dwells upon existing literature and enhances the forecasting accuracy of crude oil volatility by fusing a neural network model with multiple econometric models.     

A hybrid method of exponential smoothing and recurrent neural networks for time series forecasting

This paper presents the winning submission of the M4 forecasting competition. The submission utilizes a dynamic computational graph neural network system that enables a standard exponential smoothing model to be mixed with advanced long short term memory networks into a common framework. The result is a hybrid and hierarchical forecasting method.     

基于LSTM深度学习的大豆期货价格预测

面对越来越复杂的金融市场环境,以传统统计学和计量学为主的时间序列预测模型在发现序列中的长期依赖关系方面存在一定局限性,而深度学习中的长短期记忆(LSTM)网络有望克服这一问题。通过构造一个多层LSTM网络价格预测模型,使用中国2007—2019年大豆期货价格数据进行了实证研究。结果显示,参数调优对LSTM网络模型预测效果有着较大影响,其中影响较大的主要参数包括迭代次数、学习率、窗口大小和网络层数等;与ARIMA模型、MLP模型、SVR模型相比,LSTM网络模型的预测结果准确性更高,在拟合优度(R-2)上分别提高了1.064%、2.147%、1.674%。LSTM网络模型在价格预测方面的良好表现,为预测大豆期货价格提供了新思路。     

Does beta react to market conditions? Estimates of ‘bull’ and ‘bear’ betas using a nonlinear market model with an endogenous threshold parameter

The authors use a logistic smooth transition market (LSTM) model to investigate whether ‘bull’ and ‘bear’ market betas for Australian industry portfolios returns differ. The LSTM model allows the data to determine a threshold parameter that differentiates between ‘bull’ and ‘bear’ states, and it also allows for smooth transition between these two states. Their results indicate that ‘bull’ and ‘bear’ betas are significantly different for most industries, and that up-market risk is not always lower than down-market risk. LSTM models indicate that the transition between ‘bull’ and ‘bear’ states is abrupt, supporting a dual-beta market modelling framework.     

Exploring the attention mechanism in LSTM-based Hong Kong stock price movement prediction

State-of-the-art methods using attention mechanism in Recurrent Neural Networks have shown exceptional performance targeting sequential predictions and classifications. We explore the attention mechanism in Long–Short-Term Memory (LSTM) network based stock price movement prediction. Our proposed model significantly enhances the LSTM prediction performance in the Hong Kong stock market. The attention LSTM (AttLSTM) model is compared with the LSTM model in Hong Kong stock movement prediction. Further parameter tuning results also demonstrate the effectiveness of the attention mechanism in LSTM-based prediction method.     

Forecasting the realized volatility of Energy Stock Market: A multimodel comparison

The realized volatility forecasting of energy sector stocks facilitates the establishment of corresponding risk warning mechanisms and investor decisions. In this paper, we collected two different energy sector indices and used different methods, namely principal component analysis (PCA) and sparse principal component analysis (SPCA), to extract features, and combined LSTM and GRU to construct 12 different models. The results show that the SPCA-LSTM model we constructed has the best forecasting performance in the realized volatility forecasting of energy indices, and SPCA has better forecasting results than PCA in the feature extraction stage. The results of the robustness test indicate that our results are robust.     

基于LSTM法的高速公路边坡稳定性研究

为了准确分析高速公路边坡性状,确保路基的稳定性,结合高速公路边坡环境特征,以边坡监测数据为基础,利用长短期记忆人工神经网络(LSTM)方法建立了高速公路边坡稳定性预测模型。以影响边坡稳定性的边坡质量系数、边坡结构系数、坡高系数、坡角系数、工程因素等因素为评估依据,采用降噪补缺、数据变换等方法处理LSTM前端数据,利用LSTM方法计算高速公路边坡稳定系数,与递归神经网络(RNN)方法进行比较。结果表明,高速公路边坡预测稳定系数为1.69,边坡安全稳定性良好,且符合实际。新方法的最大相对误差为1.60%,绝对MAPE仅为1.80%,较传统RNN方法预测更加精准。所得结论验证了深度学习在边坡稳定性预测评估过程中的有效性,对深入研究公路边坡稳定性具有借鉴价值。     

Tail risk of coal futures in China's market

This study evaluates the downside tail risk of coal futures contracts (coke, coking coal and thermal coal) traded in the Chinese market between 2011 and 2021, measured by value at risk (VaR). We examine the one-day-ahead VaR forecasting performance with a hybrid econometric and deep learning model (GARCH-LSTM), GARCH family models, extreme value theory models, quantile regression models and two naïve models (historical simulation and exponentially weighted moving average). We use four backtesting techniques and the model confidence set to identify the optimal models. The results suggest that the models focusing on tail risk or utilising long short-term memory generate more effective risk management.     

Forecasting Commodity Market Returns Volatility: A Hybrid Ensemble Learning GARCH-LSTM based Approach

This study investigates the advantage of combining the forecasting abilities of multiple generalized autoregressive conditional heteroscedasticity (GARCH)-type models, such as the standard GARCH (GARCH), exponential GARCH (eGARCH), and threshold GARCH (tGARCH) models with advanced deep learning methods to predict the volatility of five important metals (nickel, copper, tin, lead, and gold) in the Indian commodity market. This paper proposes integrating the forecasts of one to three GARCH-type models into an ensemble learning-based hybrid long short-term memory (LSTM) model to forecast commodity price volatility. We further evaluate the forecasting performance of these models for standalone LSTM and GARCH-type models using the root mean squared error, mean absolute error, and mean fundamental percentage error. The results highlight that combining the information from the forecasts of multiple GARCH types into a hybrid LSTM model leads to superior volatility forecasting capability. The SET-LSTM, which represents the model that combines forecasts of the GARCH, eGARCH, and tGARCH into the LSTM hybrid, has shown the best overall results for all metals, barring a few exceptions. Moreover, the equivalence of forecasting accuracy is tested using the Diebold–Mariano and Wilcoxon signed-rank tests.