  If Ultra-High Energy Cosmic Rays (UHECRs) are originated from nearby
galaxies, modeling of the distribution of nearby galaxies is important to an
accurate estimate the source number density of UHECRs. We investigate
uncertainty of the selection function of the Optical Redshift Survey (ORS),
which we used to construct a source model of UHECRs. The investigation is based
on a comparison of numbe counts of ORS galaxies with those of the spectroscopic
sample of the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR). We
carefully count galaxies in the same absolute magnitude bin from the two
samples. We find a slight systematic overestimate of the ORS counts outside
5000 km s$^{-1}$ by about a factor of 2. We revise the selection function of
the ORS assuming that the SDSS counts are correct. Our revision is based on the
absorption given in the ORS catalog as well as that computed from Schlegel et
al. (1998), which is systematically larger than the former by $A_B \sim 0.1$
mag in the region of low absorption. It is found that introduction of Schlegel
et al.'s absorption changes one of the parameters of the ORS selection function
by more than 10%. The revision should be taken into account in the future
analysis of the source number density of UHECRs based on the ORS. Using the
revised selection function, we determine the global structure of the Local
Supercluster (LSC) with a source model of UHECRs, that is, a number-density
model consisting of a uniform spherical halo and an exponential disk. We find
that the revision is insignificant in terms of the structure of the LSC.
However, the revised selection function will be useful to other studies such as
peculiar velocity and correlation function.
