The effect of spectrum sensing errors on the performance of orthogonal frequency division multiplexing based cognitive radio transmission can be evaluated by deriving the expression for the average bit error rate. This depends on various parameters like transmission and spectrum sensing parameters. Here, we consider the case with adding a carrier frequency offset. The spectrum sensing errors of...

In this paper, the optical properties of one dimensional fractal structures are investigated. We consider six typical fractal photonic structures: the symmetric dual cantor-like fractal structure, the asymmetric dual cantor-like fractal structure, the single cantor-like fractal structure, the symmetric dual golden-section fractal structure, the asymmetric dual golden-section fractal structure a...

Transmission eigenvalues are points in the spectrum of the interior transmission operator, a coupled 2x2 system of elliptic partial differential equations, where one unknown function must satisfy two boundary conditions and the other must satisfy none. We show that the interior transmission eigenvalues are discrete and depend continuously on the contrast by proving that the interior transmissio...

The transition from a spectrum filter (resonant transmission) to a polarizer (broadband transmission) for TM polarized light is observed in a metallic nano-slit array as period is decreased. A theoretical model is developed and shows that the spectrum filter behavior is caused by the coupled slit/grating resonance. With decreasing period, the slit resonance is decoupled from the grating resonan...

An adaptive transmission protocol is described and evaluated for use in wireless communication networks that employ dynamic spectrum assignment. The protocol interacts with a spectrum assignment system to select the modulation format and symbol transmission rate for each session. The power is adjusted during the initial part of each session, and code-rate adaptation is employed to compensate fo...

The Lyman-alpha forest has become an important tool for measuring the mass power spectrum at high redshifts (z = 2−4). A crucial intermediate step is the measurement of the transmission power spectrum. We present new methods to minimize the systematic and random errors for such a measurement, and discuss their implications for observing strategies. Sources of systematic errors explored include ...

land. Furthermore, Ct. felis often feeds on humans. Clinicians encountering patients with fever or rash (or both) and a history of cat contact or flea bites should consider a diagnosis of R. felis. Laboratory confirmation of infection is not easy, but in vitro culture of R. felis, and hence material for a serologic assay for the diagnosis of human R. felis infections, has recently been describe...

The rapid proliferation of independently-designed and -deployed wireless sensor networks extremely crowds the wireless spectrum and promotes the emergence of cognitive radio sensor networks (CRSN). In CRSN, the sensor node (SN) can make full use of the unutilized licensed spectrum, and the spectrum efficiency is greatly improved. However, inevitable spectrum sensing errors will adversely interf...