A consistent estimator for spectral density matrix of a discrete time periodically correlated process

 In this article, we introduce a weighted periodogram in the class of smoothed periodograms as a consistent estimator for the spectral density matrix of a periodically correlated process. We derive its limiting distribution that appears to be a certain finite linear combination of Wishart distribution. We also provide numerical derivations for our smoothed periodogram and exhibit its asymptotic consistency using simulated data. In this article, we introduce a weighted periodogram in the class of smoothed periodograms as a consistent estimator for the spectral density matrix of a periodically correlated process. We derive its limiting distribution that appears to be a certain finite linear combination of Wishart distribution. We also provide numerical derivations for our smoothed periodogram and exhibit its asymptotic consistency using simulated data

Drivers’ Addiction Toward Cell Phone Use While Driving

Background: The use of a cell phone when driving has been recognized as a type of distraction worldwide. Addictive tendency to use technology, including cell phone use while driving may be a substantial problem for drivers and increasing risk of accidents. The aim of this study was to evaluate the effect of drivers’ addiction to use a cell phone while driving.  Materials and Methods: A sample of 400 drivers with ages 18-65 years old completed a questionnaire which was designed based on Theory of Planned Behavior (TPB). Hierarchical regression analysis was utilized to predict drivers’ addiction to use a cell phone while driving on demographic characteristics and TPB components.  Results: Drivers had mean age of 35.63(8.72) and were 77% male, and 23% female. Tests of validity and reliability were conducted for every variable. According to findings, the hierarchical regression analysis model showed that the TPB was able to predict 59% variance in addiction toward cell phone use and attitude emerging as the strongest predictor during this analysis. All components of TPB were more independent to age than gender. Conclusion: The fundamental TPB components were directly associated with the addiction to use a cell phone when driving. The present study has identified that older drivers were considerably less probable to use a cell phone while driving. Also this study showed that males use a cell phone significantly more frequent. More practical road safety measures are required to rebuff and mitigate the effects of using cell phones while driving