Volume 4 of OAML presents advancements in machine learning optimization across diverse fields. Key studies explore adaptive algorithms in motor design, applying graph neural networks for enhanced performance. Another work addresses optimization in mobile robotic delivery systems, focusing on deep-learning approaches to improve routing and efficiency. In online advertising, researchers investigate models to refine predictive accuracy for targeted services. Financial markets also see innovation, with a stock recommendation model leveraging time-frequency analysis. Lastly, cybersecurity is strengthened through a novel end-to-end learning model for intrusion detection, enhancing data protection.