Recommended by Mischa Dohler Cognitive Radio (CR), a hierarchical Dynamic Spectrum Access (DSA) model, has been considered as a strong candidate for future communication systems improving spectrum efficiency utilizing unused spectrum of opportunity. However, to ensure the effectiveness of dynamic spectrum access, accurate signal classification in fading channels at low signal to noise ratio is ...

Understanding how the human visual system recognizes objects is one of the key challenges in neuroscience. Inspired by a large body of physiological evidence, a general class of recognition models has emerged, which is based on a hierarchical organization of visual processing, with succeeding stages being sensitive to image features of increasing complexity. However, these models appear to be i...

When a patient falls asleep, he transits by different sleep stages, which characterize the quality of his night. To determine these sleep stages, the technicians visually analyzes the polysomnographic signals (PSG) witch have different aspects according to these stages. However, this task requires a lot of time. This is why one generally tries to class them automatically. Then, one is generally...

The neural correlates of the wake-sleep continuum remain incompletely understood, limiting the development of adaptive drug delivery systems for promoting sleep maintenance. The most useful measure for resolving early positions along this continuum is the alpha oscillation, an 8-13 Hz electroencephalographic rhythm prominent over posterior scalp locations. The brain activation signature of wake...

OBJECTIVE To objectively record sleep patterns in intensive care unit patients using the Bispectral Index as an electroencephalographic measure of sleep and to determine if the sleep pattern is correlated with various clinical factors. METHODS Adult intensive care patients were recruited who were in the recovery phase of their illness and on minimal sedation. The sleep pattern was examined us...

Information processing has been suggested to depend on the current state of the brain as well as stimulus characteristics (e.g. salience). We compared processing of salient stimuli (subject's own names [SONs] and angry voice [AV] stimuli) to processing of unfamiliar names (UNs) and neutral voice (NV) stimuli across different vigilance stages (i.e. wakefulness as well as sleep stages N1 and N2) ...

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CONTEXT AND OBJECTIVE Information on the correlation of normative reproductive hormone levels with physical development (Tanner stages) during puberty and on the influences of genes and environment on variation in these hormones and Tanner stages is limited. DESIGN, SETTING, AND PARTICIPANTS One hundred twelve healthy 9-year-old twin pairs (n = 224) took part in a longitudinal study, of which...

Lineage-specific transcription factors (TFs) display instructive roles in directly reprogramming adult cells into alternate developmental fates, in a process known as transdifferentiation. The present study analyses the hypothesis that despite being fast, transdifferentiation does not occur in one step but is rather a consecutive and hierarchical process. Using ectopic expression of Pdx1 in hum...

each license plate recognition system is composed of three main parts, namely, license plate detection, character segmentation and character recognition. in this paper, we focus on the improvement and innovation of the character recognition step. for this purpose, a new hierarchical architecture based on support vector machines (svms) is suggested for persian license plate characters recognitio...