Convolutional neural networks (CNNs) have been applied to visual tasks since the late 1980s. However, despite a few scattered applications, they were dormant until the mid-2000s when developments in computing power and the advent of large amounts of labeled data, supplemented by improved algorithms, contributed to their advancement and brought them to the forefront of a neural network renaissance that has seen rapid progression since 2012. In this review, which focuses on the application of CNNs to image classification tasks, we cover their development, from their predecessors up to recent state-of-the-art deep learning systems. Along the way, we analyze (1) their early successes, (2) their role in the deep learning renaissance, (3) selected symbolic works that have contributed to their recent popularity, and (4) several improvement attempts by reviewing contributions and challenges of over 300 publications. We also introduce some of their current trends and remaining challenges.

The advance in technologies such as e-commerce and financial technology (FinTech) applications have sparked an increase in the number of online card transactions that occur on a daily basis. As a result, there has been a spike in credit card fraud that affects card issuing companies, merchants, and banks. It is therefore essential to develop mechanisms that ensure the security and integrity of credit card transactions. In this research, we implement a machine learning (ML) based framework for credit card fraud detection using a real world imbalanced datasets that were generated from European credit cardholders. To solve the issue of class imbalance, we re-sampled the dataset using the Synthetic Minority over-sampling TEchnique (SMOTE). This framework was evaluated using the following ML methods: Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), Extreme Gradient Boosting (XGBoost), Decision Tree (DT), and Extra Tree (ET). These ML algorithms were coupled with the Adaptive Boosting (AdaBoost) technique to increase their quality of classification. The models were evaluated using the accuracy, the recall, the precision, the Matthews Correlation Coefficient (MCC), and the Area Under the Curve (AUC). Moreover, the proposed framework was implemented on a highly skewed synthetic credit card fraud dataset to further validate the results that were obtained in this research. The experimental outcomes demonstrated that using the AdaBoost has a positive impact on the performance of the proposed methods. Further, the results obtained by the boosted models were superior to existing methods.

The ascent of Industry 4.0 and smart manufacturing has emphasized the use of intelligent manufacturing techniques, tools, and methods such as predictive maintenance. The predictive maintenance function facilitates the early detection of faults and errors in machinery before they reach critical stages. This study suggests the design of an experimental predictive maintenance framework, for conveyor motors, that efficiently detects a conveyor system’s impairments and considerably reduces the risk of incorrect faults diagnosis in the plant; We achieve this remarkable task by developing a machine learning model that classifies whether the abnormalities observed are production-threatening or not. We build a classification model using a combination of time-series imaging and convolutional neural network (CNN) for better accuracy. In this research, time-series represent different observations recorded from the machine over time. Our framework is designed to accommodate both univariate and multivariate time-series as inputs of the model, offering more flexibility to prepare for an Industry 4.0 environment. Because multivariate time-series are challenging to manipulate and visualize, we apply a feature extraction approach called principal component analysis (PCA) to reduce their dimensions to a maximum of two channels. The time-series are encoded into images via the Gramian Angular Field (GAF) method and used as inputs to a CNN model. We added a parameterized rectifier linear unit (PReLU) activation function option to the CNN model to improve the performance of more extensive networks. All the features listed added together contribute to the creation of a robust future proof predictive maintenance framework. The experimental results achieved in this study show the advantages of our predictive maintenance framework over traditional classification approaches.