Human detection sensor (or infrared sensor) can detect the existence of human based on the fact that a human body is actually a "heat source". In this research, we arrange several sensors in the form of a matrix (see the main image), and try to propose theories and technologies for detecting not only the existence, but also the positions and the activity patterns of some person in a certain region. Sub-image 1 shows the region covered by a sensor array with 7 sensors. Through this project, students are expected to learn basics related construction of wireless sensor network, data analysis, and pattern recognition. All these should be helpful for the students to find a good job in some IT companies.