As IoT applications proliferate, they will become more sophisticated. Many of these new applications will intimately
involve humans, i.e., humans and things will operate synergistically. Human in-the-loop systems offer exciting opportunities to a broad range of applications including energy management [17], health care [15], and automobile systems [9], [16]. For example, it is hypothesized that explicitly incorporating human-in-the loop models for driving can improve safety, and using models of activities of daily living in home health care can improve medical
conditions of the elderly and keep them safe. Although having humans in the loop has its advantages, modeling human behaviors is extremely challenging due to the complex physiological, psychological, and behavioral aspects of human beings. New research is necessary to raise human-in-the-loop control to a central principle in system design and to solve three main challenges [20].