  We have studied the dynamics of morphology-dependent resonances by openness
in a dielectric microdisk for TE polarization. For the first time, we report
that the dynamics exhibits avoided resonance crossings between inner and outer
resonances even though the corresponding billiard is integrable. Due to the
avoidance, inner and outer resonances can be exchanged and $Q$-factor of inner
resonances is strongly affected. We analyze the diverse phenomena aroused from
the dynamics including the avoided crossings.
