Intermittent brightenings observed by the AIA. Panels a and b: time-sequence of AIA 171 Å and 304 Å images displaying repeatedly occurred EUV bursts at the site of the flux cancelation. The black box shows the region for integrating the intensity. Panel c: HMI LOS magnetograms with red/blue contours representing the positive/negative magnetic fields of ±100 G. The cyan line represents the PIL, and P1 (P2) and N represent the positive and negative polarities, respectively.