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The present study investigated the gender-related influence of electromagnetic fields (EMF), similar to that emitted by mobile phones, on brain activity. Ten women and nine men performed a short memory task (Wechsler test), both without (baseline) and with exposure to a 900 MHz signal. The EEG energy of the total waveform and the alpha, beta, delta and theta; rhythms were calculated from the recordings of 15 scalp electrodes. Baseline EEG energy of males was greater than that of females, while exposure to EMF decreased EEG energy of males and increased that of females. Memory performance was invariant to EMF exposure and gender influences. These findings indicate that EMF may exert a gender-related nfluence on brain activity.

Abstract-The interaction of a helical antenna, mounted on a mobile handset, with a human head phantom is investigated in this paper. Using the Genetic Algorithms (GA) technique combined with the Method of Moments (MoM), an optimization of the antenna structure is achieved regarding the input impedance at the operating frequency. The Finite Difference Time Domain (FDTD) method is then applied to simulate the handset's function in the close region of a spherical homogeneous and heterogeneous head phantom. A formula, based on an application of an existing model proposed by Kuster and Balzano for dipole antennas, provides a rather accurate prediction of the induced Specific Absorption Rate (SAR) values in the human head due to the radiating helical antenna. The concept of relating the SAR to the current on the antenna is used in this study to formulate the final expression. Moreover, using the theory of regression, the results of the calculated peak or average SAR are correlated with the distance between the antenna and phantom and with the standing wave ratio (SWR) at the antenna feed point. Thus, the conception that the SAR is indeed related to the antenna operational parameters is reinforced by the outcome of the current study.

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The usability of wireless sensor networks in modern applications requires the fulfillment of dynamic Quality of Service (QoS) requirements that can only be met in a reactive manner by the introduction of composite routing metrics, capturing several distinct network characteristics. However, combining routing metrics is neither a trivial nor an arbitrary task, given the routing protocol requirements and routing metrics properties. In this paper, the theoretical framework of routing algebra formalism is adopted and extended to incorporate single or composite routing metrics, because the satisfaction of routing algebra properties ensures convergence, optimality, and loop‐freeness. Moreover, packet forwarding indication is defined as a new trust metric for systems (a) with or (b) without network retransmissions to avoid forwarding attacks, while a novel composite routing metric is presented, combining link reliability and trust‐awareness in an additive manner, fulfilling the theoretical requirements. Finally, this composite metric is applied to the Routing Protocol for Low Power and Lossy Networks via simulations, which verify its efficiency in several scenarios, including the comparison between lexical and additive metric composition approaches. Copyright © 2012 John Wiley & Sons, Ltd.

Abstract-A method of designing smart antennas based on switched parasitic antenna arrays is presented in this paper. The direction of maximum gain can be controlled by a digital word, while the selection of element spacing and weighting is optimized using the method of genetic algorithms. Various results are presented to show how antennas of this type perform, outlining the advantages and limitations of their design.