  Newly-developed spectrographs with increased resolving powers, particularly
those covering the near-IR range, allow the characterization of more and more
absorption lines in stellar spectra. This includes the identification and
confirmation of absorption lines and the calibration of oscillator strengths.
In this study, we provide empirical values of loggf based on abundances of
classical Cepheids obtained with optical spectra in Luck (2018), in order to
establish the consistency between optical and infrared abundance results. Using
time-series spectra of classical Cepheids obtained with WINERED spectrograph
(0.97-1.35 $\mu$ m, R ~28000, we demonstrate that we can determine the stellar
parameters of the observed Cepheids, including effective temperature (Teff),
surface gravity (logg), microturbulence, and metallicity. With the newly
calibrated relations of line-depth ratios (LDRs), we can achieve accuracy and
precision comparable to optical studies (Luck 2018), with uncertainties of 90K
and 0.108 dex for Teff, and log g, respectively. Finally, we created a new
atlas of absorption lines, featuring precise abundance measurements of various
elements found in the atmosphere of Cepheids (including neutron-capture
elements), with loggf values that have been astrophysically calibrated.
