Deep Learning Models for Price Prediction in Travertine Stone Mines: A Comparison of LSTM, Transformer, and Hybrid Models
Abstract
This study aims to develop and evaluate four deep learning models for forecasting the monthly prices offered by stone suppliers in Iran. Given the simultaneous influence of temporal factors (such as exchange rate, inflation, fuel price, and order volume) and static attributes (including block quality, brand reputation, and cooperation history), each model was designed with a dual-input structure to separately process sequential and non-sequential features, which are then integrated at a later stage. The implemented architectures include LSTM, Bi-LSTM, Transformer, and a hybrid Transformer+LSTM+CLS model. The models were trained and evaluated using data collected from five different mines over several months, ensuring robustness and generalizability across diverse supply sources and time periods. Model performance was assessed using key evaluation metrics including Mean Absolute Error (MAE), Mean Squared Error (MSE), Root Mean Squared Error (RMSE), the coefficient of determination (R²), and validation loss. The results indicate that the Transformer model achieved the highest accuracy, with the lowest prediction errors and the best generalization capability. The hybrid model also performed comparably well, making it a robust alternative for more complex forecasting tasks. In contrast, the Bi-LSTM model underperformed and is less recommended for this application. Overall, the findings highlight that combining attention-based architectures with sequential analysis provides an effective solution for price forecasting in data-driven and competitive industrial contexts.
Keywords:
Price forecasting, Deep learning models, Transformer architecture, Time series forecasting, Stone suppliers, Data-drivenReferences
- [1] Cortez, C. A. T., Saydam, S., Coulton, J., & Sammut, C. (2018). Alternative techniques for forecasting mineral commodity prices. International journal of mining science and technology, 28(2), 309–322. https://doi.org/10.1016/j.ijmst.2017.09.001
- [2] Shi, H., Wei, A., Xu, X., Zhu, Y., Hu, H., & Tang, S. (2024). A CNN-LSTM based deep learning model with high accuracy and robustness for carbon price forecasting: A case of Shenzhen’s carbon market in China. Journal of environmental management, 352, 120131. https://doi.org/10.1016/j.jenvman.2024.120131
- [3] Sun, T., Li, H., Wu, K., Chen, F., Zhu, Z., & Hu, Z. (2020). Data-driven predictive modelling of mineral prospectivity using machine learning and deep learning methods: A case study from southern Jiangxi Province, China. Minerals, 10(2), 102. https://doi.org/10.3390/min10020102
- [4] James, A., Mahmud, R., Afrin, M., Mistry, S., & Krishna, A. (2023). Performance optimisation of regression-based machine learning models to predict mineral land prices for tokenization. 2023 IEEE engineering informatics (pp. 1-7). IEEE. https://doi.org/10.1109/IEEECONF58110.2023.10520573
- [5] Shi, T., Li, C., Zhang, W., & Zhang, Y. (2023). Forecasting on metal resource spot settlement price: New evidence from the machine learning model. Resources policy, 81, 103360. https://doi.org/10.1016/j.resourpol.2023.103360
- [6] Dumakor-Dupey, N. K., & Arya, S. (2021). Machine learning—a review of applications in mineral resource estimation. Energies, 14(14), 4079. https://doi.org/10.3390/en14144079
- [7] Yang, K., Zhang, X., Luo, H., Hou, X., Lin, Y., Wu, J., & Yu, L. (2024). Predicting energy prices based on a novel hybrid machine learning: Comprehensive study of multi-step price forecasting. Energy, 298, 131321. https://doi.org/10.1016/j.energy.2024.131321
- [8] Zhang, K., Cao, H., Thé, J., & Yu, H. (2022). A hybrid model for multi-step coal price forecasting using decomposition technique and deep learning algorithms. Applied energy, 306, 118011. https://doi.org/10.1016/j.apenergy.2021.118011
- [9] Yang, H., & Schell, K. R. (2022). GHTnet: Tri-Branch deep learning network for real-time electricity price forecasting. Energy, 238, 122052. https://doi.org/10.1016/j.energy.2021.122052
- [10] Lehna, M., Scheller, F., & Herwartz, H. (2022). Forecasting day-ahead electricity prices: A comparison of time series and neural network models taking external regressors into account. Energy economics, 106, 105742. https://doi.org/10.1016/j.eneco.2021.105742
- [11] Barzinpour, F., Moazeni, H., & Pishvai, M. (2016). A data envelopment analysis (DEA) model for supplier selection by considering sustainable criteria: A case study in a stone industry. Strategic management researches, 21(59), 89–115. (In Persian). https://smr.journals.iau.ir/article_525059_0.html
- [12] Khoshalan, H. A., Shakeri, J., Najmoddini, I., & Asadizadeh, M. (2021). Forecasting copper price by application of robust artificial intelligence techniques. Resources policy, 73, 102239. https://doi.org/10.1016/j.resourpol.2021.102239
- [13] He, K., Yang, Q., Ji, L., Pan, J., & Zou, Y. (2023). Financial time series forecasting with the deep learning ensemble model. Mathematics, 11(4), 1054. https://doi.org/10.3390/math11041054
- [14] SaeediAghdam, M., Sadeghi, A., Bahiraei, A., & HajiAsghari, S. Y. (2022). Presenting a stock price prediction model using deep learning algorithms and its application in the pricing of Islamic banks’ stocks. Quarterly journal of islamic economics and banking, 4, 117–134. (In Persian). http://mieaoi.ir/article-1-964-fa.html
- [15] Kiyani Mavi, R., & Sayadi Nik, K. (2015). Using different learning algorithms in the stock price prediction by using neural networks. Journal of development & evolution mnagement, 1393(Spec. Issue), 75–81. (In Persian). https://sanad.iau.ir/en/Article/949971?FullText=FullText
- [16] Gholami, N., & Shams Gharne, N. (2024). Presenting an optimized CNN-LSTM model for stock price forecasting in the tehran stock exchange. Financial management perspective, 14(45), 123–147. https://doi.org/10.48308/jfmp.2024.104892
- [17] Farmani, A., & Jahangiri, S. (2023). Comparing the performance of metaheuristic algorithms in predicting stock prices in the tehran stock exchange market. Majlis and economy, 1(2), 128-152. (In Persian). https://doi.org/10.22034/mec.2024.16767.1029
- [18] Nikparvar, S., Ahmadi, F., & Kalbkhani, H. (2024). Forecasting the price of cryptocurrencies using meta-learning algorithms. Iranian journal of wargaming, 7(14), e209992. https://doi.org/10.22034/ijwg.2024.472660.1090
- [19] Mathotaarachchi, K. V., Hasan, R., & Mahmood, S. (2024). Advanced machine learning techniques for predictive modeling of property prices. Information, 15(6), 295. https://doi.org/10.3390/info15060295

