We introduce a new approach for nonparametric spectral density estimation based on the subsampling technique, which we apply to important class of nonstationary time series. These are almost periodically correlated sequences. In contrary existing methods, our technique does not require demeaning data. On simulated data examples, compare estimator function with classical one. Additionally, propo...

date fruit, containing a substantial amount of carbohydrates is considered as an important agricultural product in iran. in this research, the objective was the use date fruit wastes to produce bioethanol. for better understanding of the fermentation process the changes in sugar content, as well as the amount of produced bioethanol and carbon dioxide were periodically measured and modeled while...

this paper studies a maintenance policy for a system composed of two components, which are subject to continuous deterioration and consequently stochastic failure. the failure of each component results in the failure of the system. the components are inspected periodically and their deterioration degrees are monitored. the components can be maintained using different maintenance actions (repair...

Periodically-poled ferroelectric crystals show unprecedented efficiency and properties otherwise impossible to reach. Unfortunately, the sample thickness obtainable today limits their use to low and moderate power application. With the aim of increasing the size of periodically domain-structured crystals with a controlled and regular grating period, we proposed an epitaxial growth process using...