  We investigate the impact of the surface brightness (SB) limit on the galaxy
stellar mass functions (GSMFs) using mock surveys generated from the Horizon
Run 5 (HR5) simulation. We compare the stellar-to-halo-mass relation, GSMF, and
size-stellar mass relation of the HR5 galaxies with empirical data and other
cosmological simulations. The mean SB of simulated galaxies are computed using
their effective radii, luminosities, and colors. To examine the cosmic SB
dimming effect, we compute $k$-corrections from the spectral energy
distributions of individual simulated galaxy at each redshift, apply the
$k$-corrections to the galaxies, and conduct mock surveys based on the various
SB limits. We find that the GSMFs are significantly affected by the SB limits
at a low-mass end. This approach can ease the discrepancy between the GSMFs
obtained from simulations and observations at $0.625\le z\le 2$. We also find
that a redshift survey with a SB selection limit of $\left<\mu_r\right>^e =$ 28
mag arcsec${}^{-2}$ will miss 20% of galaxies with $M_\star^g=10^{9}~{\rm
M_\odot}$ at $z=0.625$. The missing fraction of low-surface-brightness galaxies
increases to 50%, 70%, and 98% at $z=0.9$, 1.1, and 1.9, respectively, at the
SB limit.
