Mean JHK Magnitudes of Fundamental-Mode Cepheids from Single-Epoch   Observations
  We present an empirical method for converting single-point near-infrared J, H, and K measurements of fundamental-mode Cepheids to mean magnitudes, using complete light curves in V or I bands. The algorithm is based on the template light curves in the near-infrared bandpasses. The mean uncertainty of the method is estimated to about 0.03 mag, which is smaller than the uncertainties obtained in other approaches to the problem in the literature. 
I. Soszynski, W. Gieren, G. Pietrzynski