The NBS Boulder Laboratory has recently completed installation of a 6.1 meter Ku-band (14/12 GHz) satellite earth station and has acquired two 1.8 meter portable earth terminals and commercial spreadspectrum modems. This equipment was procured for the purpose of doing two-way time transfer experiments in collaboration with other timekeeping laboratories. Each portable earth terminal, often call...

Congestion remains a major challenge to telecommunications service provision both to the service providers as well as the subscribers. We attempted to determine the causes of congestion and evaluated congestion control mechanisms adopted by service providers in Nigeria using MTN Nigeria as a case study. A survey research design methodology using stratified random sampling technique was employed...

PURPOSE To discuss the use of wavefront measurements generated from the NIDEK OPD-Scan II and OPD-Station for cataract surgery. METHODS Case examples are presented along with information and relevant clinical data obtained from the OPD-Scan II aberrometer and OPD-Station software. All eyes underwent corneal topography, wavefront aberrometry, autorefraction, keratometry, and pupillometry measu...

To investigate approaches for parameterizing cloud cover effects in models of surface irradiance, the daily-averaged and hourly irradiances measured at Palmer Station (64°46'S, 64°3'W), McMurdo Station (77°5l'S, 166°40'E) and Ushuaia (54°49'S, 68°19'W) between 1993 and 1997 were compared to irradiance values computed with a clear sky radiative transfer model in which nine empirical cloud-cover ...

Service discovery is one of the most pivotal roles played in the design of wireless network. This is because the nodes do not have any prior knowledge of resource availability. Cooperative Mapping of Obstacles (CMO) in wireless networks extract information based on minimum wireless measurements but the feedback received from communication signal strength was not used for further alignment. The ...

With the rapid advancement of wireless network technologies and the rapid increase in the number of mobile devices, mobile users (MUs) have an increasing high demand to access the Internet with guaranteed quality-of-service (QoS). Data and energy integrated communication networks (DEINs) are emerging as a new type of wireless networks that have the potential to simultaneously transfer wireless ...

Aerosol optical depth (AOD) is a critical variable in estimating aerosol concentration in the atmosphere, evaluating severity of atmospheric pollution, and studying their impact on climate. With the assistance of the 6S radiative transfer model, we simulated apparent reflectancein relation to AOD in each Moderate Resolution Imaging Spectroradiometer (MODIS) waveband in this study. The closeness...