Cognitive radio reduces the spectral inefficiency by sensing the under and over utilized parts of the spectrum and then redistributing the transmission to ensure that the spectrum is used efficiently. The awareness about spectrum usage is obtained by spectrum sensing. Cyclostationary feature detections one of the spectrum sensing techniques for cognitive radio. In this paper, we detect the pres...

We report Hubble Space Telescope optical to near-infrared transmission spectroscopy of the hot-Jupiter WASP-6b, measured with the Space Telescope Imaging Spectrograph and Spitzer’s InfraRed Array Camera. The resulting spectrum covers the range 0.29–4.5μm. We find evidence for modest stellar activity of WASP-6 and take it into account in the transmission spectrum. The overall main characteristic...

Efficient utilization of spectrum resources is a fundamental issue of wireless communications due to its scarcity. To improve the efficiency of spectrum utilization, the spectrum sharing for unlicensed bands is being regarded as one of key technologies in the next generation wireless networks. A number of schemes such as Listen-Before-Talk(LBT) and carrier sensor adaptive transmission (CSAT) ha...

A simple one-pot process to exfoliate graphite and synthesize nanographene-dimesitylporphyrin hybrids has been developed. Despite the bulky mesityl groups, which are expected to hinder the efficient π-π stacking between the porphyrin core and graphene, the liquid-phase exfoliation of graphite is significantly favored by the presence of the porphyrins. Metallation of the porphyrin further enhanc...

Cognitive radio (CR) is one of the key enabling technologies for opportunistic spectrum sharing. In such a spectrum sharing paradigm, radios access spectrum opportunistically by identifying the under-utilized spectrum and then transmitting waveforms in that spectrum that are compliant to relevant spectrum access policies. Implementing such a flexible scheme requires changes in the current stati...

let $r$ be a commutative ring and let $m$ be an $r$-module. in this article, we introduce the concept of the zariski socles of submodules of $m$ and investigate their properties. also we study modules with noetherian second spectrum and obtain some related results.

a multicone graph is defined to be join of a clique and a regular graph. a graph $ g $ is  cospectral with  graph $ h $ if their adjacency matrices have the same eigenvalues. a graph $ g $ is  said to be  determined by its spectrum or ds for short, if for any graph $ h $ with $ spec(g)=spec(h)$, we conclude that $ g $ is isomorphic to $ h $. in this paper, we present new classes of  multicone g...

We present Hubble Space Telescope (HST) optical transmission spectra of the transiting hot Jupiter WASP-12b, taken with the Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the range 2900 to 10300 Å which we combined with archival WFC3 spectra and Spitzer photometry to cover the full optical to infrared wavelength regions. With high spatial resolution, we are ...

With the increasing emergence of new wireless systems and the explosive development of mobile internet applications, the demands on Radio Frequency spectrum have been constantly increasing, and therefore, the related demands for bandwidth, wireless communication technology is facing a potentially scarcity of radio spectrum resources. However, spectrum measurement campaigns have shown that the s...