In this paper we search for an orbital modulation of the VHE γ-ray flux in LS 5039, a High Mass X-ray Binary that consists of a compact object in an 3.9 days orbit around a massive star. For this purpose we apply to archive HESS data of LS 5039 two methods: Least-Squares Spectral Analysis (LSSA) or Lomb-Scargle test, which has been proved effective in this task previously, and Period Determinat...

Levelling is the most precise technique for height difference measurements in geomatics engineering. Various systematic errors affect precise levelling observations and reduce the precision of the observed height differences. This study investigates digital levels residual compensator error and observational method for its elimination. For this purpose the levelling data, which was collected wi...

Abstract We investigate the effect of radio-frequency interference (RFI) excision in estimating cosmological H i 21 cm power spectrum. Flagging RFI-contaminated channels results a nonuniform sampling instrumental bandpass response. Hence, Fourier transformation visibilities from frequency to delay domain contaminates higher foreground-free modes, and separating spectrally fluctuating signal smo...

Partial least square (PLS) analysis is the most favourite tool in chemometrics to develop calibration models. PLS technique allows us decipher even complex systems by analysing all variables instead of looking at them one a time. not only capture maximum variation associated with predictor (i.e. spectra) and predicted concentration) but also maximises correlation between them. The present artic...

The recognition and the calculation of all branches of solutions of the nonlinear boundary value problems is difficult obviously. The complexity of this issue goes back to the being nonlinearity of the problem. Regarding this matter, this paper considers steady state reactive transport model which does not have exact closed-form solution and discovers existence of dual or triple solutions in so...