Satoru Aikawa

With the recent expansion of electromagnetic (EM) waves, undesired EM waves generated by device can cause malfunctions of other electronic equipment and communication failure. EM wave absorbers are widely used as countermeasures against these problems. Therefore, EMC (Electromagnetic Compatibility) technology is reguired to improve the electromagnetic environment. In this study, a microwave metamaterial EM wave absorbers using a sheet with a periodic array of square metal patterns were designed and its reflection characteristics at vertical incidence were experimentally evaluated.

This contribution focuses on the accuracy and measurement cost of indoor Area Estimation using wireless LAN. The system estimates the area, such as a room or a shopping store, where the user is located. The user-measured AP information (UD), and the pre-measured AP information (DB) are used in the FP method. In the previous study, RSSI probability distributions were obtained from the measured DB and UD. The area with the largest overlap in probability distribution was selected as the estimation result. In this study, we propose Area Estimation by CNN using data measured while walking at various locations within an area. The method using CNN improved the estimation accuracy compared to conventional Area Estimation. Moreover, the method measuring AP information while walking reduced the measurement time.