  Simultaneous excitation of low-frequency eccentric precessing mode (one-armed
p-mode) and tilt mode on tidally deformed disks is considered. If the orbit of
the secondary star is eccentric and its orbital plane is misaligned with the
disk plane of the primary, the above-mentioned two low-frequency oscillation
modes are simultaneously excited on the primary disk, the former having
prograte precession and the latter having retrograde precession. This
excitation of disk oscillations is due to a wave-wave resonant excitation
process considered by Kato (2013). If parameter values relevant to Be/X-ray
binary systems are adopted, the periods of these excited oscillations are
around ten times of the orbital period of the secondary, which may be
comparable with the time scale of giant outbursts observed in Be/X-ray systems.
