In the current world of the Internet of Things, cyberspace, mobile devices, businesses, social media platforms, healthcare systems, etc., there is a lot of data online today. Machine learning (ML) is something we need to understand to do smart analyses of these data and make smart, automated applications that use them. There are many different kinds of machine learning algorithms. The most well-known ones are supervised, unsupervised, semi-supervised, and reinforcement learning. This article goes over all the different kinds of machine-learning problems and the machine-learning algorithms that are used to solve them. The main thing this study adds is a better understanding of the theory behind many machine learning methods and how they can be used in the real world, such as in energy, healthcare, finance, autonomous driving, e-commerce, and many more fields. This article is meant to be a go-to resource for academic researchers, data scientists, and machine learning engineers when it comes to making decisions about a wide range of data and methods to start extracting information from the data and figuring out what kind of machine learning algorithm will work best for their problem and what results they can expect. Additionally, this article presents the major challenges in building machine learning models and explores the research gaps in this area. In this article, we also provided a brief overview of data protection laws and their provisions in different countries.

Several critical infrastructures are integrating information technology into their operations, and as a result, the cyber attack surface extends over a broad range of these infrastructures. Cyber attacks have been a serious problem for industries since the early 2000s, causing significant interruptions to their ability to produce goods or offer services to their clients. The thriving cybercrime economy encompasses money laundering, black markets, and attacks on cyber-physical systems that result in service disruptions. Furthermore, extensive data breaches have compromised the personally identifiable information of millions of people. This paper aims to summarize some of the major cyber attacks that have occurred in the past 20 years against critical infrastructures. These data are gathered in order to analyze the types of cyber attacks, their consequences, vulnerabilities, as well as the victims and attackers. Cybersecurity standards and tools are tabulated in this paper in order to address this issue. This paper also provides an estimate of the number of major cyber attacks that will occur on critical infrastructure in the future. This estimate predicts a significant increase in such incidents worldwide over the next five years. Based on the study’s findings, it is estimated that over the next 5 years, 1100 major cyber attacks will occur on critical infrastructures worldwide, each causing more than USD 1 million in damages.

Software-Defined Networking (SDN) is a network architecture that decouples the control plane from the data plane, enabling centralized, programmable management of network traffic. SDN introduces centralized control and programmability to modern networks, improving flexibility while also exposing new security vulnerabilities across the application, control, and data planes. This paper provides a comprehensive overview of SDN security threats and defenses, covering recent developments in controller hardening, trust management, route optimization, and anomaly detection. Based on these findings, we present a comparative analysis of SDN controllers in terms of performance, scalability, and deployment complexity. This culminates in the introduction of the Cloud-to-Edge Layer Two (CELT)-Secure switch, a virtual OpenFlow-based data-plane security mechanism. CELT-Secure detects and blocks Internet Control Message Protocol flooding attacks in approximately two seconds and actively disconnects hosts engaging in Address Resolution Protocol-based man-in-the-middle attacks. In comparative testing, it achieved detection performance 10.82 times faster than related approaches.

This work presents a Kalman filter-based harmonic mitigation technique that can be used to reduce the total harmonic distortion (THD) of grid-injected current by reducing the harmonic distortion. Throughout the power supply system, power electronic converters have become increasingly used in recent years, which has resulted in more reactive power and harmonics. In a power system, harmonics add to noise and lower power quality. A study in MATLAB/Simulink 2022b for improving the THD of renewable energy injected grid currents using seven-level packed u-cells (PUC7) has been undertaken to improve the grid-injected current THD with Kalman filter-based harmonic mitigation technique. With the Kalman filter-based harmonic mitigation techniques, the THD for the grid-injected current is improved from 6.32 to 2.49% when compared to the grid-injected current without the Kalman filter-based technique.