This paper considers cooperative spectrum sensing algorithms for Cognitive Radios which focus on reducing the number of samples to make a reliable detection. We develop an energy efficient detector with low detection delay using decentralized sequential hypothesis testing. Our algorithm at the Cognitive Radios employs an asynchronous transmission scheme which takes into account the noise at the...

Channel assignment mechanisms in multi-channel wireless networks are often designed without accounting for adjacent-channel interference (ACI). To prevent such interference between different users in a network, guard-bands (GBs) are needed. Introducing GBs has significant impact on spectrum efficiency. In this paper, we present channel assignment mechanisms that aim at maximizing the spectrum e...

Tetracyclines (TCs) are broad-spectrum antibiotics that are used widely in veterinary medicine. The present study was carried out to trace the residues of oxytetracycline (OTC) and tetracycline (TC) in pasteurized milk that is marketed in Tehran with the use of a High Performance Liquid Chromatography (HPLC). Ninety milk samples were collected during five sequential days from the products of si...

The operator A r̃, s̃ on sequence space on p is defined A r̃, s̃ x rkxk skxk 1 ∞ k 0, where x xk ∈ p, and r̃ and s̃ are two convergent sequences of nonzero real numbers satisfying certain conditions, where 1 < p < ∞ . The main purpose of this paper is to determine the fine spectrum with respect to the Goldberg’s classification of the operator A r̃, s̃ defined by a double sequential band matrix over the...

obtaining a seismic section with high temporal and spatial resolution was always one of the goals of seismic data processors and interpreters. accurate estimation of the thicknesses of thin beds is an important tool in this regard. the basic problem is that the wavelength of the signal must be similar in dimention to that of the bed thinness. if it is much longer than the bed thinness, the dete...

there are many different ways to subdivide the spectrum of a bounded linear operator; some of them aremotivated by applications to physics (in particular, quantum mechanics). in this study, the relationship betweenthe subdivisions of spectrum which are not required to be disjoint and goldberg's classification are given.moreover, these subdivisions for some summability methods are studied.