This special issue contains 10 papers, which highlight the frontiers of applied intelligence. The themes of the papers cover applications of intelligent systems from various fields of artificial intelligence, such as agent-based systems, pattern recognition, and decision-making techniques. The first paper, “Detecting Changing Emotions in Human Speech by Machine and Humans”, by Natalie van der Wal and Wojtek Kowalczyk, considers the development of a system that is able to automatically measure changes of a speakers emotional state. The authors achieve this goal by analyzing the speaker’s voice, the validation of the system with a controlled experiment, and the visualization of the results. Various features are extracted from speeches, and machine learning algorithms are applied over the selected features, in order to predict the direction of emotion changes in speech. The second paper, “Dynamic Game with Perfect and Complete Information Based Dynamic Channel Assignment”, by Xiaochen Lai, Quanli Liu, Wei Wang, Likun Li, Simin Lu, and Ying Zhao, deals with the channel assignment strategy within Ad Hoc networks. The authors propose a novel algorithm of channel assignment based on complete and perfect information dynamic game theory. In contrast to traditional algorithms, the throughput and saturation throughput could be improved; meanwhile the packet loss rate and network delay could be reduced. The third paper, “Detection of JPEG Double Compression and Identification of Smartphone Image Source and Post-capture Manipulation”, by Qingzhong Liu, Peter Cooper, Lei Chen, Hyuk Cho, Zhongxue Chen, Mengyu Qiao, Yuting Su, Mingzhen Wei, and Andrew Sung, focuses