extensive researches on wireless sensor networks (wsns) have been performed and many techniques have been developed for the data link (mac) layer. most of them assume single-channel mac protocols. in the usual dense deployment of the sensor networks, single-channel mac protocols may be deficient because of radio collisions and limited bandwidth. hence, using multiple channels can significantly ...

Visible Light Communication (VLC), which is based on the idea of using light sources used for lighting in data transmission, expected to be among communication technologies future. However, reliable communication, it important know and predict indoor VLC channels that are known have a multipath structure. Therefore, order examine possible channel characteristics, multiple transmitter rooms with...

In CDMA (Code - Division Multiple - Access) systems multi - user accessing of a channel is possible. Under the assumptions of Optimum multi - user and decorrelating detector in CDMA systems. By using signals with zero and / or identical cross correlations, a simple and expandable decorrelating detector with optimum efficiency which can be easily implemented are proposed. Constructing these sign...

We report a 61-year-old man with multiple colored skin papules with central crusts in an archiform and linear pattern on his forehead as well as verrucus and hyperkeratotic plaques with central perforation on hands. Histologic examination of the lesions demonstrated a narrow channel of epidermal perforation containing notrophils, basophilic debris and elastic fibers with eosinophilic degenerati...