“…Many sensors around us are generally used to gather information that is referred to as "big data" on work efficiency, safety, security, environment, medicine, industry, agriculture, and social infrastructure. [1][2][3][4] In the near future, sensor-based big data are expected to bring new business opportunities, leading to better management of smart cities, healthcare services, environmental protection, and disaster monitoring. Among the different kinds of sensors, pyroelectric infrared sensors are non-contact-type thermal sensors that can detect human body, gas, and abnormal heat generation by receiving infrared rays emitted from humans and heat sources.…”