An optimized ensemble framework for machinery fault detection in IoT environments

An ensemble deep learning model for exhaust emissions prediction of heavy oil-fired boiler combustion

Child mortality is a big problem around the world, especially in low- and middle-income nations where there are big differences in health care and social conditions. This investigation seeks to create a predictive model for child mortality and pinpoint the key factors that significantly contribute to it, employing machine learning (ML) methodologies. The dataset includes various features such as parental age, maternal education, birth weight, wealth index, and access to healthcare services. Thirteen machine learning classifiers were used, categorized into four model groups: Traditional Models (Logistic Regression, K-Nearest Neighbors, Support Vector Machine, Naive Bayes), Tree-Based Models (Decision Tree, Random Forest, Extra Trees), Boosting Models (AdaBoost, Gradient Boosting, XGBoost), and Ensemble Learning Models (Soft Voting, Hard Voting, Stacking). The efficacy of each model was assessed using classification metrics, including Accuracy, Precision, Recall, and F1-Score within a 10-fold cross-validation framework to guarantee robustness. Results indicate that ensemble models, particularly AdaBoost, achieved the highest predictive accuracy, with perfect scores across all metrics (1.00). XGBoost and Stacking also demonstrated strong and consistent performance. The findings indicate that ensemble learning methods are effective in predicting child mortality and can assist policymakers and healthcare planners in identifying high-risk populations and implementing targeted interventions to reduce child mortality.

Threats in the digital landscape increased as different emerging technologies progress. Despite the various implementations of different defensive measures and tools to monitor and detect traffic anomaly, complexity and cost are the main challenges for small to medium enterprise networks. This study developed a malicious traffic detection system that utilized signature-based and anomaly-based techniques through packet analysis and network flow using machine learning algorithms. The system consists of a Raspberry Pi-based packet capturing tool, website application, implored with Ensemble Learning Model to detect and classify malicious network traffic. The ensemble learning model which includes weak learners like Decision Tree, Naïve Bayes and Support Vector Machine (SVM), in which individual results are combined and boosted using XG Boost algorithm. CTU-13 and CSE-CIC-IDS2018 datasets were used for training and validating the model. The ensemble learning model achieved an accuracy of 96.42%, precision of 98.99%, recall of 93.79%, and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{F 1}$</tex>-score of 96.32% for the binary classification using the validation data. Moreover, the model also achieved an accuracy of 96.39%, precision of 95.82%, recall of 96.39%, and F1-score of 95.66% for the multiple classification. The ensemble machine learning model was also evaluated using generated traffic, resulting in a decline in performance: accuracy dropped to 60.94%, precision to 44.44%, recall to 30.77%, and the F1-score to 61.54%.

Purpose This study aims to propose a new ensemble learning model and compare its performance with other ensemble models to obtain the best model for detecting financial statement fraud during the COVID-19 pandemic. Design/methodology/approach This study uses a quantitative approach, using secondary data from financial reports, annual reports, regulatory reports and other information on the internet. It focuses on all companies listed on the Indonesia Stock Exchange from 2020 to 2023. The independent variables in this study use financial and nonfinancial variables. In contrast, the target variable for fraudulent financial reports is based on sanctions from regulators and the company’s special supervisory status. Findings This study results show that the ensemble blending model performs best in detecting financial statement fraud compared to the ensemble model that construct it. Research limitations/implications This study sets ensemble learning to default settings. Setting certain conditions can further improve the performance of ensemble learning models. Practical implications This study can broaden the insights of practitioners, academics, investors, regulators, stakeholders and corporate finance experts into detecting financial report fraud. Originality/value This study proposes a new ensemble learning model that previous studies have not discussed. This ensemble learning model performs best compared to other ensemble learning models.

Background: Breast cancer is one of the leading causes of death in women, making early detection through mammography crucial for improving survival rates. However, human interpretation of mammograms is often prone to diagnostic errors. This study addresses the challenge of improving the accuracy of breast cancer detection by leveraging advanced machine learning techniques. Methods: We propose an extended ensemble deep learning model that integrates three state-of-the-art convolutional neural network (CNN) architectures: VGG16, DenseNet121, and InceptionV3. The model utilizes multi-scale feature extraction to enhance the detection of both benign and malignant masses in mammograms. This ensemble approach is evaluated on two benchmark datasets: INbreast and CBIS-DDSM. Results: The proposed ensemble model achieved significant performance improvements. On the INbreast dataset, the ensemble model attained an accuracy of 90.1%, recall of 88.3%, and an F1-score of 89.1%. For the CBIS-DDSM dataset, the model reached 89.5% accuracy and 90.2% specificity. The ensemble method outperformed each individual CNN model, reducing both false positives and false negatives, thereby providing more reliable diagnostic results. Conclusions: The ensemble deep learning model demonstrated strong potential as a decision support tool for radiologists, offering more accurate and earlier detection of breast cancer. By leveraging the complementary strengths of multiple CNN architectures, this approach can improve clinical decision making and enhance the accessibility of high-quality breast cancer screening.

Interpreting and explaining complex models such as ensemble machine learning models for opinion mining is essential to increase the level of transparency fairness and reliability of positive and negative opinion prediction results. Although ensemble learning models offer significant benefits, their lack of interpretability poses a major challenge in understanding the rationale behind their prediction, creating a complex problem related to the interpretation of the model. There is also limited research on developing ensemble learning models that describe the internal function and behavior of the model. In this paper, we propose a new approach for opinion mining with random density forest interpretation to provide explanatory power in opinion mining. Using the Local Interpretable Model-agnostic Explanation (LIME), we further interpret the random density forest model leading to the prediction of opinion polarization in opinion mining according to specific domains related to online reviews of restaurants and hotels. It has demonstrated accurate results in terms of the contribution of opinion features in mining the overall opinion. In addition, we also compared the probability density of opinion feature words and were interested in the contribution of essential features to the results. Model prediction using the SHAPLEY value, based on the interaction value of opinion feature words, has shown the level of influence in predicting positive or negative opinion polarization results. Empirical results show that the proposed system tries to explain efficiency.

Online fault detection in industrial machinery, such as induction motors or their components (e.g., bearings), continues to be a priority. Most commercial equipment provides general measurements and not a diagnosis. On the other hand, commonly, research works that focus on fault detection are tested offline or over processors that do not comply with an online diagnosis. In this sense, the present work proposes a system based on a proprietary field programmable gate array (FPGA) platform with several developed intellectual property cores (IPcores) and tools. The FPGA platform together with a stray magnetic flux sensor are used for the online detection of faults in the outer race of bearings in induction motors. The integrated parts comprising the monitoring system are the stray magnetic flux triaxial sensor, several developed IPcores, an embedded processor for data processing, and a user interface where the diagnosis is visualized. The system performs the fault diagnosis through a statistical analysis as follows: First, a triaxial sensor measures the stray magnetic flux in the motor’s surroundings (this flux will vary as symptoms of the fault). Second, an embedded processor in an FPGA-based proprietary board drives the developed IPcores in calculating the statistical features. Third, a set of ranges is defined for the statistical features values, and it is used to indicate the condition of the bearing in the motor. Therefore, if the value of a statistical feature belongs to a specific range, the system will return a diagnosis of whether a fault is present and, if so, the severity of the damage in the outer race. The results demonstrate that the values of the root mean square (RMS) and kurtosis, extracted from the stray magnetic field from the motor, provide a reliable diagnostic of the analyzed bearing. The results are provided online and displayed for the user through interfaces developed on the FPGA platform, such as in a liquid crystal display or through serial communication by a Bluetooth module. The platform is based on an FPGA XC6SLX45 Spartan 6 of Xilinx, and the architecture of the modules used are described through hardware description language. This system aims to be an online tool that can help users of induction motors in maintenance tasks and for the early detection of faults related to bearings.

Early and correct classification of neurodegenerative diseases like Alzheimer's Disease (AD) and Frontotemporal Dementia (FTD) is one of the most important challenges in clinical neurology. In this paper, we present a novel electroencephalogram (EEG)-based approach that integrates a rich set of multiresolution features to improve the performance of automatic classification. Our approach fuses the Graph Fourier Transform (GFT), Graph Wavelet Transform (GWT), Discrete Wavelet Transform (DWT), and a newly developed Graph Empirical Mode Decomposition (GEMD) technique to primarily boost the performance of the proposed model. This also retained the complementary spatial, spectral, and temporal information carried by the EEG signals, which are significant for the differentiation of AD, FTD, and HC subjects. The EEG recordings were segmented into fixed lengths with non-overlapping windows of four durations: 1000, 5000, 10,000, and 20,000 samples. Energy and entropy features were obtained for each segment, both individually within domains and combined into a single 388-dimensional feature vector. The features were then normalized and fed into various machine learning (ML) models, including support vector machines (SVMs), k-nearest neighbors (kNNs), decision trees (DTs), random forests (RFs), and an ensemble learning model with the AdaBoost capability. The proposed model was tested using accuracy, precision, recall, specificity, and F1-scores, with results showing that the ensemble model was better than the other benchmark models in every classification task. That is, in this binary classification problem, an accuracy of 98.84% for AD vs. HC, 98.67% for AD vs. FTD, and 98.94% for FTD vs. HC was obtained. In the multiclass task (AD, FTD, HC), the method reached 96.68% accuracy, demonstrating the efficacy of the proposed method for the identification of Alzheimer's disease and frontotemporal dementia. Compared to previous research using the same dataset, our approach has demonstrated improved performance, validating the effectiveness of graph-based multiresolution feature fusion for dementia classification using EEG signals.

Based on multi-algorithm hybrid method to predict the slope safety factor-- stacking ensemble learning with bayesian optimization

Lymph node metastasis is a critical factor for determining therapeutic strategies and assessing the prognosis of early gastric cancer. This work aimed to establish a more dependable predictive model for identify lymph node metastasis in early gastric cancer. The study utilized both univariate and multivariate logistic regression analyses to identify independent risk factors for lymph node metastasis of early gastric cancer, while employing five distinct algorithms to calculate feature weights. The optimal feature combination for each algorithm model was determined by combining the six highest weight features from all five models along with the independent risk factors. An ensemble learning model was subsequently constructed by integrating these five models. The model’s performance was evaluated by the AUC, accuracy, and F1 score. Following this, a threshold was determined based on the F1 score, and the model’s performance was assessed using an external validation set. The lymph node metastasis rate of early gastric cancer in our study was 16.4%. The ensemble learning model achieved an AUC value of 0.860 in the test set, with an accuracy of 82.35% and an F1 score of 0.611. Based on the F1 score, the model’s threshold was set at 0.18. Additionally, the model demonstrated an AUC of 0.892 in the external validation set, along with an accuracy of 78.30% and an F1 score of 0.60.We constructed an ensemble learning model for predicting lymph node metastasis of early gastric cancer. Gastric surgery should be considered as the preferred treatment when the risk of lymph node metastasis exceeds 18%.

Background and Objectives: We aimed to apply the ensemble machine learning model to diagnose thyroid cartilage invasion detected in computer tomography (CT) images in laryngeal cancers and evaluate the diagnostic performance of the model. Materials and Methods: A total of 313 patients were divided into two groups: the cartilage invasion group and the no cartilage invasion group. At least four CT slices were randomly selected for each patient, resulting in a total of 1251 images used in the study. A total of 619 axial CT images from the no cartilage invasion group and 632 axial CT images from the cartilage invasion group were used in the study. We reviewed the CT images and histopathological diagnoses in all cases to determine the invasion positive- or negative-status as a ground truth. The ensemble model, comprising ResNet50 and MobileNet deep learning architectures, was applied to CT images. Results: The following were obtained by the ensemble model with the test dataset: area under the curve (AUC) 0.99, and accuracy 96.54%. This model demonstrates a very high level of performance in detecting thyroid cartilage invasion. Conclusions: The ensemble machine learning model is an effective method for detecting neoplastic infiltration of the thyroid cartilage. Moreover, it may be a valuable diagnostic tool for clinicians in assessing disease prognosis and determining appropriate treatment strategies in laryngeal cancers. In conclusion, this model could be integrated into future clinical practice in laryngology and head and neck surgery for the detection of cartilage neoplastic infiltration.

The gearbox is one of the crucial components in wind turbines, and its performance degradation would give rise to out-of-order or even damage. To accurately identify the fault of the gearbox, a novel fault diagnosis approach based on the ensemble model and the dung beetle optimization algorithm is introduced. Firstly, an ensemble learning model with different activation functions is established. Secondly, the dung beetle optimization is applied to select the base models for improving the performance and generalization ability of the ensemble model. Finally, the proposed method is tested with a gearbox dataset. The experimental results show that the proposed approach achieves higher diagnostic accuracy on the gearbox dataset.

While the rapid development of vaccines during the COVID-19 pandemic helped save billions of lives, a significant percentage of the population reported adverse reactions after vaccination. Post-vaccination surveys were conducted to understand the possible side effects. Analyzing and understanding the side effects enables the relevant stakeholders to gain more understanding of the vaccine and allows the individual to make informed decisions about whether to receive the vaccine. This work aims to identify a robust approach that can be used to predict the possibility of potential adverse symptoms. A dataset comprising 840 participants with 15 Post-Vaccination Symptoms was considered for the study. Synthetic Minority Oversampling TEchnique (SMOTE) was used to handle the class imbalance of the dataset. A combination of SMOTE and ensemble machine learning models was used to predict the adverse reactions to COVID-19 vaccines. The ensemble Machine Learning (ML) models that are considered for this study are Random Forest, Extreme Gradient Boosting Machine (XGBoost), Light Gradient Boosting Machine, and AdaBoost. The metrics accuracy, precision, recall and Receiver Operating Characteristic-Area Under the Curve (ROC-AUC) were used to measure the performance of the models. The dataset was pre-processed to handle missing values and one-hot encoding was applied to convert categorical variables into the numerical format. Insights into the data distribution and relationships between variables were gained through exploratory data and correlation analysis, respectively. Class imbalance in the target variables was addressed using SMOTE, resulting in a significantly improved F1-score and ROC-AUC score. Among the ensemble ML models, XGBoost delivered the best performance metrics. A combined performance score was calculated by averaging the F1-score and accuracy to identify the best model. XGBoost obtained the highest performance score among the ensemble ML models, and its performance is further enhanced by performing the threshold adjustment using the maximum F1- score strategy. The findings suggest that the combination of SMOTE and ensemble learning models with threshold adjustment provides a more efficient prediction of adverse effects after COVID-19 vaccination, aiding in healthcare decision-making.

The Internet of Things (IoT) has emerged as a crucial expansion of Internet services, linking numerous devices that produce and exchange substantial quantities of data. Strong defense against evolving cyberattacks that jeopardize the confidentiality, integrity, and availability (CIA Triad) of IoT systems is necessary due to this interconnectedness. Therefore, by controlling network activity to stop invasions and identify odd data patterns, intrusion detection systems can offer a robust layer of security for IoT systems. With a focus on identifying less frequent Advanced Persistent Threats (APT), this study aims to detect attacks directed at the CIA Triad. We examined two popular and unbalanced data sets, TON-IoT and BoT-IoT, for anomaly detection in IoT networks. By examining the usefulness of the ensemble learning and deep learning models in anomaly detection inside the IoT network data, we were able to study the security element of the network. The ensemble learning models considered are the following. Random Forest, XGBoost, and Stacking. The considered deep learning models are as follows: BiLSTM, GRU, Autoencoder, and Self-Taught Learning (STL: AE-SVM). The performance metrics studied are as follows: Accuracy, False Alert Rate, Recall, Precision, and F1-score. Regrettably, there were instances in which anomalies could not be detected using conventional techniques. This is because labeled data is scarce, particularly for APT attacks, and attack traffic is frequently sparse and noisy. We suggested a deep self-taught learning system (STL: AE-XGB) based on Transfer Learning to detect anomalies in IoT network data to tackle these difficult issues. To enhance classification performance and capture the changing landscape of attack methods in IoT networks. Our models automatically augment annotated data. The results show that our proposed model (STL: AE-XGB) outperforms the conventional models studied and provides interesting results in binary and multiclass classification.

Previous studies on landslide susceptibility (LS) and hazard (LH) assessments have overlooked a crucial measure for evaluating validation effectiveness, which involves the use of post-temporal landslide inventories instead of solely relying on historical data. Therefore, this study constructed a regional LH prediction and validation framework at different timescales using the landslide data from 2002 to 2021. Firstly, based on updated landslide data and conditioning factors, the datasets for susceptibility modelling were built for various periods. Then, the performances of traditional ma chine learning, ensemble and deep learning models were compared. Finally, the multi-period rainfall data and susceptibility results were used in innovative LH forecasting. Our study results show that the ensemble learning model (random forest) has stronger generalisation ability in different time periods, with all Area Under Curve (AUC) values exceeding 0.9. The hazard modelling framework based on rainfall erosion intensity and susceptibility can effectively forecast LH, and the shortened timescale for rainfall erosion intensity can improve the accuracy of LH forecasting. At the very high hazard level, the percentage of landslides forecast increased from 25.23% to 42.86%. This study comprehensively explores spatio-temporal dynamic changes in LH, accurately identifying areas posing threats to the National Transmission Line Protection Regions (NTLPR).