  We study the effects of Janus oscillators in a system of phase oscillators in
which the coupling constants take both positive and negative values. Janus
oscillators may also form a cluster when the other ones are ordered and we
calculate numerically the traveling speed of three clusters emerging in the
system and average separations between them as well as the order parameters for
three groups of oscillators, as the coupling constants and the fractions of
positive and Janus oscillators are varied. An expression explaining the
dependence of the traveling speed on these parameters is obtained and observed
to fit well the numerical data. With the help of this, we describe how Janus
oscillators affect the traveling of the clusters in the system.
