  We estimate the polarized thermal dust emission from MHD simulations of
protostellar collapse and outflow formation in order to investigate alignment
of outflows with magnetic fields. The polarization maps indicate that alignment
of an outflow with the magnetic field depends on the field strength inside the
cloud core; the direction of the outflow, projected on the plane of the sky, is
aligned preferentially with the mean polarization vector for a cloud core with
a magnetic field strength of 80 microgauss, while it does not tend to be
aligned for 50 microgauss as long as the 1000 AU scale is considered. The
direction of the magnetic field at the cloud center is probed by the direction
of the outflow. In addition, the magnetic field at the cloud center can be
revealed by ALMA even when the source is embedded deeply in the envelope. The
Chandrasekhar-Fermi formula is examined using the polarization maps, indicating
that the field strength predicted by the formula should be corrected by a
factor of 0.24 - 0.44. The correction factor has a tendency to be lower for a
cloud core with a weaker magnetic field.
