Large-Scale Surveys of Pulsating Stars for Studying Stellar Populations
  in the Inner Galaxy
  Surveys of pulsating stars in the inner Galaxy have been very limited, but
recent large-scale surveys are rapidly bringing us new samples of various kinds
of variable stars and new insights into stellar populations therein. Because of
the severe interstellar extinction along the Galactic disc, the stellar
populations in the inner Galaxy are more easily observed in the infrared, but
even in the infrared the interstellar extinction may cause a serious problem in
revealing their accurate characteristics. Here we review recent discoveries of
Cepheids and Miras, two kinds of luminous pulsating stars with
period-luminosity relation, in the inner Galaxy.
