This book features selected papers from the 9th International Conference in Advanced Engineering—Theory Applications (AETA 2024), during 7–8 November, in Brno, Czech Republic. The topics of the papers cover three main topics: energy (energy saving power electronics, electrical machines and drive systems, green-energy IT, nontrivial dynamics of electronic devices); control engineering (robotics, automatic control, biosensor IT); communication and security (broadcasting IT, communications, cyber security). Its content caters to researchers, scientist, and engineers who are interested in scientific achievements and advanced technologies of electrical, electronic-telecommunication, computer science, and mechanical-mechatronics engineering.