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In this paper, Proactive Unified Spectrum Handoff (PUSH) scheme in cognitive radio mobile ad hoc networks (CR-MANETs) through an established route is considered in which the channel availability depends on the Primary User's (PU's) activity, secondary user's (SU's) mobility, and the channel heterogeneity. First, an analytical model for Unified Spectrum Handoff (USH) scheme is introduced in which the...
The paper addresses the Unified Handoff Management (UHM) scheme in Cognitive Radio Mobile Ad hoc Networks (CR-MANETs) with multiple users. In order to model the UHM, three key factors are considered: (1) channel availability and spectrum usage behaviors of the primary users (PUs); (2) the movements and the motility of the secondary users (SUs); and (3) channel heterogeneity and channel quality degradation...
The paper introduces proactive integrated handoff management (IHM) scheme in cognitive radio mobile ad hoc networks (CR-MANETs) through an established route. This scheme considers the primary user (PU) activity, secondary user (SU) mobility and channel heterogeneity in the spectrum handoff decision. To reduce the handoff delay, handoff thresholds are used. When the spectrum handoff cannot be done...
In cognitive radio (CR), CR users or also known as secondary users (SUs) are considered as “visitors” to the licensed spectrum. During the case when the primary user (PU) claims the band of the spectrum that is occupied by the SU, the SU's ongoing call must be transferred to another unused spectrum band. The variation in spectrum band is called spectrum mobility. Spectrum mobility leads to a new handoff...
Image watermarking, the process of embedding data into a cover image and extract watermark under different attacks, can be used primarily for copyright protection and other purposes. Two key components in watermarking are perceptual transparency and robustness of the watermark. A tradeoff between these two features exists, which can be introduced as an optimization problem. Simulated annealing and...
Watermarking image, the process of embedding data into a cover image and extract watermark under different attacks, can be used primarily for copyright protection and other purposes. Two key components in watermarking are perceptual transparency and robustness of the watermark. A tradeoff between these two features exists, which can be introduced as an optimization problem. Simulated annealing (SA)...
An optimum demodulator for chaotic parameter modulation (CPM) is presented in this paper. A binary mapping model is used for time-varying bifurcation parameter of logistic map to increase the security of communication. Due to dynamic behavior of such a system, a combined extended Kalman filter (EKF) and hidden Markov model (HMM) is used as detector which provide time domain processing. EKF is used...
An optimum demodulator for chaotic parameter modulation (CPM) is presented in this paper. A binary mapping model is used for time-varying bifurcation parameter of logistic map to increase the security of communication. Due to dynamic behavior of such a system, a combined extended Kalman filter (EKF) and hidden Markov model (HMM) is used as detector which provide time domain processing. EKF is used...
Speech production and speech phonetic features gradually improve in children by obtaining audio feedback after cochlear implantation or using hearing aid. In this study, voice disorders in children with cochlear implantation and hearing aid are classified. 30 Persian children participated in the study, including 6 children in levels 1 to 3 and 12 in level 4. Voice samples of 5 isolated Persian words...
A methodology for fast synthesis of analog circuits based on adaptive network fuzzy inference system (ANFIS) and evolutionary optimization is presented in this work. The method is based on establishment of a surrogate nonlinear model which improves the efficiency of computational tasks and also increases the design accuracy. Furthermore, development of an ANFIS coarse model provides further reduction...
Lipreading is a main part of audio-visual speech recognition systems which are mostly faced with redundancy of extracted features. In this paper, a new approach has been proposed to increase the lipreading performance by extraction of discriminant features. In this way, first, faces are detected; then, lip key points are extracted in which four cubic curves characterize lip contours. Next, the visual...
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