Material written for traditional textbooks is increasingly being made available via online textbooks. Such material still uses text and drawings to explain concepts. In contrast, material written natively for the web can use less text and drawings, and instead use animations, responsive questions, and interactive exercises. This work compares the lesson effectiveness of electronic textbooks hav...

In order to provide robust, tolerant and stable media access control to the wireless ad-hoc community network, we propose a demand-assigned CDMA-TDMA scheme that is a combination of CDMA and demandassigned TDMA. In this network, traffic load, the number of users and the logical/physical topology fluctuate dynamically. We originated that the channel assignment strategy based on the number of pac...