Machine learning-based design of target property-oriented fuels using explainable artificial intelligence

The accurate prediction of the residual strength of defective pipelines is a critical prerequisite for ensuring the safe operation of oil and gas pipelines, and it holds significant implications for the pipeline’s remaining service life and preventive maintenance. Traditional machine learning algorithms often fail to comprehensively account for the correlative factors influencing the residual strength of defective pipelines, exhibit limited capability in extracting nonlinear features from data, and suffer from insufficient predictive accuracy. Furthermore, the predictive models typically lack interpretability. To address these issues, this study proposes a hybrid prediction model for the residual strength of defective pipelines based on Bayesian optimization (BO) and eXtreme Gradient Boosting (XGBoost). This approach resolves the issues of excessive iterations and high computational costs associated with conventional hyperparameter optimization methods, significantly enhancing the model’s predictive performance. The model’s prediction performance is evaluated using mainstream metrics such as the Mean Absolute Percentage Error (MAPE), Coefficient of Determination (R2), Root Mean Square Error (RMSE), robustness analysis, overfitting analysis, and grey relational analysis. To enhance the interpretability of the model’s predictions, reveal the significance of features, and confirm prior domain knowledge, Shapley additive explanations (SHAP) are employed to conduct the relevant research. The results indicate that, compared with Random Forest, LightGBM, Support Vector Machine, gradient boosting regression tree, and Multi-Layer Perceptron, the BO-XGBoost model exhibits the best prediction performance, with MAPE, R2, and RMSE values of 5.5%, 0.971, and 1.263, respectively. Meanwhile, the proposed model demonstrates the highest robustness, the least tendency for overfitting, and the most significant grey relation degree value. SHAP analysis reveals that the factors influencing the residual strength of defective pipelines, ranked in descending order of importance, are defect depth (d), wall thickness (t), yield strength (σy), external diameter (D), defect length (L), tensile strength (σu), and defect width (w). The development of this model contributes to improving the integrity management of oil and gas pipelines and provides decision support for the intelligent management of defective pipelines in oil and gas fields.

Prediction of stock closing price plays a critical role in financial planning, risk management, and informed investment decision-making. In this study, we propose a novel model that synergistically amalgamates Bidirectional GRU (BiGRU) with three complementary attention techniques—Top-k Sparse, Global, and Bahdanau Attention—to tackle the complex, intricate, and non-linear temporal dependencies in financial time series. The proposed Fused Attention Model is validated on two highly volatile, non-linear, and complex- patterned stock indices: NIFTY 50 and S&P 500, with 80% of the historical price data used for model learning and the remaining 20% for testing. A comprehensive analysis of the results, benchmarked against various baseline and hybrid deep learning architectures across multiple regression performance metrics such as Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAPE), and R2 Score, demonstrates the superiority and noteworthiness of our proposed Fused Attention Model. Most significantly, the proposed model yields the highest prediction accuracy and generalization capability, with R2 scores of 0.9955 on NIFTY 50 and 0.9961 on S&P 500. Additionally, to mitigate the issues of interpretability and transparency of the deep learning model for financial forecasting, we utilized three different Explainable Artificial Intelligence (XAI) techniques, namely Integrated Gradients, SHapley Additive exPlanations (SHAP), and Attention Weight Analysis. The results of these three XAI techniques validated the utilization of three attention techniques along with the BiGRU model. The explainability of the proposed model named as BiGRU based Fused Attention (BiG-FA), in addition to its superior performance, thus offers a robust and interpretable deep learning model for time-series prediction, making it applicable beyond the financial domain.

Globally, wind energy if properly harnessed, could serve as a source of energy generation in Africa. This study compared the performance of two Machine Learning (ML) algorithms (Linear regression and Random Forest) in predicting wind speed in five major cities in Africa (Yaoundé, Pretoria, Nairobi, Cairo and Abuja). Wind data were collected between January 1, 2000, and December 31, 2022, using the Solar Radiation Data Archive. The data preprocessing was carried out with 80% of the data used for training and 20% for validation. The performance of these ML algorithms was evaluated using Mean Square Error (MSE), Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and coefficient of determination (R2). The result shows that Nairobi (3.814795 m/s) closely followed by Cairo (3.606453 m/s) has the highest mean wind speed while Yaoundé (1.090512 m/s) has the lowest. Based on the performance metrics used, the two Machine Learning algorithms were competitive. Still, the Linear Regression (LR) algorithm outperformed the Random Forest Algorithm in predicting wind speed in all the selected major African cities. In Yaoundé (RMSE = 0.3892, MAE= 0.3001, MAPE =0.5030), Pretoria (RMSE=1.2339, MAE=0.9480, MAPE=0.7450) Nairobi (RMSE= 0.4223, MAE =0.6499, MAPE =0.1872), Nairobi (RMSE=0.6499, MAE=0.5171, MAPE =0.1872), Cairo (RMSE =1.0909, MAE =0.8544, MAPE =0.3541) and Abuja (RMSE = 0.70245, MAE =0.5441, MAPE= 0.4515) the Linear regression algorithms was found to outperformed Random Forest Regression. Therefore, the Linear regression algorithm is more reliable in predicting wind speed compared with the Random Forest regression.

An ensemble learning with sequential model-based optimization approach for pavement roughness estimation using smartphone sensor data

Compressive strength prediction of sustainable concrete incorporating rice husk ash (RHA) using hybrid machine learning algorithms and parametric analyses

Compressive strength is an important mechanical property of high-strength concrete (HSC), but testing methods are usually uneconomical, time-consuming, and labor-intensive. To this end, in this paper, a long short-term memory (LSTM) model was proposed to predict the HSC compressive strength using 324 data sets with five input independent variables, namely water, cement, fine aggregate, coarse aggregate, and superplasticizer. The prediction results were compared with those of the conventional support vector regression (SVR) model using four metrics, root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and correlation coefficient (R2). The results showed that the prediction accuracy and reliability of LSTM were higher with R2 = 0.997, RMSE = 0.508, MAE = 0.08, and MAPE = 0.653 compared to the evaluation metrics R2 = 0.973, RMSE = 1.595, MAE = 0.312, MAPE = 2.469 of the SVR model. The LSTM model is recommended for the pre-estimation of HSC compressive strength under a given mix ratio before the laboratory compression test. Additionally, the Shapley additive explanations (SHAP)-based approach was performed to analyze the relative importance and contribution of the input variables to the output compressive strength.

Gu et al. conducted a comprehensive survey on the design and application of electrocatalysts powered by machine learning techniques [1]. They presented a novel approach that utilizes Artificial Neural Networks (ANN) in conjunction with the SHAP (SHapley Additive exPlanations) method to optimize membrane electrode assemblies. The ANN model demonstrated high accuracy in predicting key performance metrics, achieving root mean square error (RMSE) values of 43.536 mW cm−2 for power density and 0.070 gPt kW−1 for platinum utilization. Additionally, the SHAP method was employed to identify the most influential features affecting the target outputs, providing valuable insights into the optimization process [1]. However, this paper raises significant theoretical and empirical concerns regarding the use of ANN in conjunction with SHAP due to the model-specific nature of these techniques, which can lead to erroneous interpretations. It appears that Gu et al. may not fully grasp the fundamental principles underlying machine learning. In supervised machine learning models like ANN, two types of accuracy are crucial: target prediction accuracy and feature importance reliability. While target prediction accuracy can be validated against known ground truth values, the derived feature importances from models lack equivalent ground truth for validation. As a result, achieving high target prediction accuracy does not ensure that the feature importances are also reliable, since there are no established ground truth values for these features. The function call “explain = SHAP(model)” further indicates that SHAP may inherit and potentially amplify any biases present in the feature importances derived from the underlying model (ANN), leading to misleading interpretations of the results [2-5]. This highlights the importance of critically evaluating both the predictions and the interpretability provided by model-agnostic methods like SHAP. In light of these concerns, the paper advocates for a more robust and multifaceted approach utilizing unsupervised machine learning techniques, such as Feature Agglomeration (FA) and Highly Variable Gene Selection (HVGS). FA is a dimensionality reduction technique that aggregates similar features, thereby simplifying the data set and reducing noise, which can enhance the interpretability of the model and the reliability of its predictions. HVGS focuses on selecting a subset of features that exhibit significant variability across samples, ensuring that only the most informative features are retained for further analysis. Following the feature selection process, the authors suggest employing nonlinear nonparametric statistical methods, such as Spearman's correlation, to assess the relationships between features and outcomes. Spearman's correlation evaluates the strength and direction of the association between ranked variables, making it particularly useful in identifying monotonic relationships that do not necessarily follow a linear pattern. The accompanying p-values provide a measure of statistical significance, offering insights into the reliability of these correlations. By leveraging these advanced methods, researchers can achieve a deeper understanding of the key factors influencing electrocatalyst performance, while also mitigating the risks associated with relying solely on model-specific interpretations. Yoshiyasu Takefuji completed this study and wrote this article. The author has nothing to report. The author has nothing to report. The author declares no conflicts of interest. The author has nothing to report.

Predicting interfacial tension in brine-hydrogen/cushion gas systems under subsurface conditions: Implications for hydrogen geo-storage

Drought is a complex and frequently occurring natural hazard in many parts of the world. Therefore, accurate drought forecasting is essential to mitigate its adverse impacts. This research has inferred the implication and the appropriateness of the extreme learning machine (ELM) algorithm for drought forecasting. For numerical evaluation, time series data of the Standardized Precipitating Temperature Index (SPTI) are used for nine meteorological stations located in various climatological zones of Pakistan. To assess the performance of ELM, this research includes parallel inferences of multilayer perceptron (MLP) and autoregressive integrated moving average (ARIMA) models. The performance of each model is assessed using root mean square error (RMSE), mean absolute error (MAE), mean absolute percent error (MAPE), Kling‐Gupta efficiency (KGE), Willmott index (WI), and Karl Pearson’s correlation coefficient. Generally, graphical results illustrated an excellent performance of the ELM algorithm over MLP and ARIMA models. For training data of SPTI‐1, ELM’s best performance has observed at Chitral station (RMSE = 0.374, KGE = 0.838, WI = 0.960, MAE = 0.272, MAPE = 259.59, R = 0.93). For SPTI‐1 at Astore station, the numerical results are (RMSE = 0.688, KGE = 0.988, WI = 0.997, MAE = 0.798, MAPE = 247.35). The overall results indicate that the ELM outperformed by producing the smallest RMSE, MAE, and MAPE values and maximum values for KGE, WI, and correlation coefficient values at almost all the selected meteorological stations for (1, 3, 6, 9, and 12) month time scales. In summary, this research endorses the use of ELM for accurate drought forecasting.

Optimized machine learning models for predicting crown convergence of plateau mountain tunnels

This study utilizes advanced machine learning (ML) algorithms to assess the influence of external weather-related factors on the energy efficiency (EE) of residential buildings. Two deep neural network (DNN) models were developed: a standard DNN and an enhanced one incorporating residual layers and attention mechanisms. The models were trained using a dataset comprising historical meteorological data and energy performance data from residential homes in York, UK. The investigation indicated that energy consumption is substantially influenced by meteorological factors including temperature (denoted as heating degree days (HDD) and cooling degree days (CDD)), humidity, wind velocity, and sun radiation. The random forest model surpassed previous models, attaining root mean square error (RMSE) of 0.0819 and a R 2 score of 1.0000, underscoring its exceptional capacity to represent the intricate interactions between meteorological factors and energy usage.The advanced deep neural network demonstrated favourable outcomes with an RMSE of 4.12 and a R 2 of 0.878, underscoring the significance of employing complicated architectures to represent intricate relationships. The results underscore the need of integrating ML for EE forecasting and identify critical domains for enhancing household energy consumption. The study compared multiple ML models, highlighting their benefits and weaknesses for prediction accuracy and resilience. This is followed by the application of SHAP (SHapley Additive exPlanations) to interpret model outputs and obtain an understanding of the significance of these weather features.

This study is conducted in response to the increasingly prominent climate crisis in contemporary society. It aims to contribute to the growing body of research on the application of deep learning (DL) in environmental sciences and to provide practical guidance for model selection in similar predictive tasks. To this end, the study focuses on carbon dioxide (CO2) emissions prediction, employing Multilayer Perceptron (MLP) models to analyze multi-country panel data. By integrating MLP with explainable artificial intelligence (XAI) techniques, this research not only investigates the underlying mechanisms of various factors influencing CO2 emissions but also quantifies and visualizes the contribution of different driving factors to the prediction outcomes, providing decision support for climate governance strategies. Through an analysis of global panel data, we construct a model incorporating 14 driving factors spanning multiple dimensions, including economic, social, environmental, energy, and technology aspects. To optimize the MLP model, we employ a fivedimensional hyperparameter space comprising hidden layer structure, learning rate, batch size, dropout rate, and training epochs and apply Grid Search for parameter tuning. Experimental results indicate that the MLP model achieves R2 of 0.9951, demonstrating its strong capability in highprecision nonlinear fitting under complex policy scenarios. To further enhance the interpretability of neural networks in CO2 emissions prediction, we introduce SHapley Additive exPlanations (SHAP) to quantify the marginal contributions of different driving factors. This analysis reveals that energy-related features play a dominant role in emission predictions, laying the foundation for scenario analysis and emission reduction policy evaluation. Furthermore, this study incorporates scenario analysis to simulate potential trajectories of CO2 emissions under different policy scenarios, providing a quantitative reference for future emission reduction strategies and environmental governance policies.

Many diseases, such as glaucoma, epilepsy, and cancer, are associated with carbonic anhydrase II. This makes it an important therapeutic target for these diseases. A stacked ensemble machine learning model was built to predict the binding affinity of ligands with CA II. The dataset used consists of 6,530 compounds with experimental Ki values from ChEMBL. Each molecule was represented by a set of 1,420 molecular descriptors, including Morgan fingerprints, MACCS keys, and RDKit 2D descriptors, which were refined to 1,320 features through different feature selection procedures. A stacked ensemble model which makes use of LightGBM, ExtraTrees, and a Multi-Layer Perceptron (MLP) was developed, with ridge regression as the meta-learner. The model achieved a satisfactory performance on the test set, with a root mean square error (RMSE) of 0.68 pKi units and a coefficient of determination (R²) of 0.76. SHAP (SHapley Additive exPlanations) analysis of the best-performing model provided important interpretability. The method identified some specific molecular substructures (e.g., Morgan_833), key pharmacophoric elements (MACCS_84, MACCS_33), and functional groups (e.g., primary amines) as the most impactful drivers of binding affinity. The outcome of the study aligns with established structure-activity relationships for CA II inhibitors; this validates the model's decision-making process. This work provides more than a tool for virtual screening but also offers interpretable insights to guide the rational design of novel CA II inhibitors

Macroalgae‐derived hydrogen production is a promising strategy for developing a sustainable energy era. The literature statistical analysis showed that dark fermentation (DF) fed with brown macroalgae species is the most studied due to its operational flexibility, low energy requirement, and high efficiency. Some physics‐based models have been developed to predict this process, but they are limited to a few specific operating conditions. Therefore, this study applied machine learning (ML) techniques based on the Scopus database to predict and optimize the brown macroalgae‐fed DF performance, which depends on substrate properties (e.g., contents of carbohydrates, proteins, lipids, etc.) and operating conditions (e.g., temperature, pH, inoculum amount, etc.). Among 22 proposed models, the artificial neural network (ANN) model was identified as the best model, with a high coefficient of determination value of 0.977 and a low root mean square error (RMSE) value of 5.1. Shapley additive explanations (SHAPs), partial dependence plots (PDPs), and individual conditional expectation (ICE) analyses revealed that the pretreatment application, substrate concentration, and operating time are the most influential factors. Finally, the optimal conditions for the brown macroalgae‐fed DF process were detected by implementing particle swarm optimization (PSO). The optimization results indicated that the maximum hydrogen yield could reach 213.6 mL/g‐VS when Saccharina japonica was used as the substrate, representing an increase of ~20% compared to the highest reported value. However, the optimal conditions vary depending on the performance target (i.e., hydrogen yield or production rate) and feedstock type (i.e., raw or pretreated), suggesting that energy efficiency and economics models need further investigation.

Machine learning assisted axial strength prediction models for concrete filled stainless steel tubular columns