In cognitive radio networks (CRNs), cognitive radio (CR) nodes adaptively access the spectrum aiming to maximize the utilization of the scarce resource. Crucial to the successful deployment of CRNs, security issues have begun to receive research interests recently. This article surveys the research advances in CRNs. First, the fundamentals of CRNs including the basic components (i.e., character...

Weak lensing surveys have become a powerful tool for mapping mass distributions and constraining the expansion history of our Universe, but continuum surveys must average over a large number of galaxies to average down the ellipticity noise due to the unknown ellipticity and orientation of the lensed galaxies. This Letter presents a technique for measuring weak lensing with velocity maps that a...

The paper deals to proposed a cooperative communications to exploit spatial diversity gains inherent in multi-user wireless systems without the need of multiple antennas at each node. Transmit diversity generally requires more than one antenna at the transmitter. However, many wireless devices are limited by size or hardware complexity to one antenna. Which communication channels are in use and...

In recent years, the concept of the software radio has been put forward by the international communication society. It is well known that software radio will play an important role in third generation wireless communication systems. But until now there is not an acceptable concept of software radio. How to make software radio be applicable authentically, and how to develop its ascendancy? This ...

Wireless sensor networks for building automation and energy management has made great progress in recent years, but the inherent indoor radio range limitations can make communication unpredictable and system deployments difficult. Low-power radio can be combined with low-power Power-Line Communication (PLC) to extend the range and predictability of indoor communication for building management a...

Gamma-ray Bursts (GRBs) are highly energetic events that can be observed at extremely high redshift. However, inherent bias in GRB data due to selection effects and redshift evolution significantly skew any subsequent analysis. We correct for important variables related the emission, such as burst duration, T90*, prompt isotropic energy, Eiso, rest-frame end time of plateau Ta,radio*, its corre...