In this paper, we first analyze the problems of speech and noise contamination process in noise-masking point of view, and propose a new approach to estimate degree of noise masking effect on clean speech distribution model based on sequential noise estimation. Sequential noise estimation is performed frame-by-frame using interacting multiple model (IMM) algorithm, so that realtime implementati...

We quantify sequential and nonsequential contributions in two-photon double ionization of helium atoms by intense ultrashort extreme-ultraviolet pulses with central photon energies ℏω_{ctr} near the sequential double-ionization threshold. If the spectrum of such pulses overlaps both the sequential (ℏω>54.4 eV) and nonsequential (ℏω<54.4 eV) double-ionization regimes, the sequential and nonseque...

Cooperative Spectrum Sensing (CSS) is an effective approach to overcome the impact of multi-path fading and shadowing issues. The reliability of CSS can be severely degraded under Byzantine attack, which may be caused by either malfunctioning sensing terminals or malicious nodes. Almost, the previous studies have not analyzed and considered the attack in their models. The present study introduc...

We study a sequential auction for sharing a wireless resource (bandwidth or power) among competing transmitters. The resource is assumed to be managed by a spectrum broker (auctioneer), who collects bids and allocates discrete units of the resource via a sequential second-price auction. It is well known that a second price auction for a single indivisible good has an efficient dominant strategy...

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...

This paper proposes the solution for Spectrum Sensing Problems in Cognitive Radio Networks. For this an Adaptive CUSUM based Test for signal Change Detection algorithm is used. The algorithm is based on sequential change detection techniques which is particularly effective when the parameters are not available apriori or when the correct parameter configuration and the pdf of the signal under t...

Cognitive Radios are emerging communication systems which efficiently utilise the unused licensed radio spectrum called spectral holes. They run Spectrum sensing algorithms to identify these spectral holes. These holes need to be identified at very low SNR (≤ −20 dB) under multipath fading, unknown channel gains and noise power. Cooperative spectrum sensing which exploits spatial diversity has ...

In this paper, we exploit channel diversity for opportunistic spectrum access (OSA). Our approach uses instantaneous channel quality as a second criterion (along with the idle/busy status of the channel) in selecting channels to use for opportunistic transmission. The difficulty of the problem comes from the fact that it is practically infeasible for a cognitive radio (CR) to first scan all cha...