A statistical model of interference in wireless networks, network-scale fading and outage probability-network density tradeoff

A novel statistical model of interference in wireless networks is proposed. The model is based on the traditional propagation channel model, which includes the average path loss as well as the large-scale and small-scale fading. In addition to these two traditional types of fading, a new concept of network-scale fading is introduced, which is due to a random spatial distribution of transmitters and receivers of the network over a large region of space occupied by the whole network. This new type of fading complements the small-scale (e.g. Rayleigh) and large-scale (e.g. lognormal) ones, is on the scale exceeding that of the other two and is independent of them. Its probability density function is derived for typical network configurations and propagation channel conditions. Network-level analysis of interference effects is given, which includes estimation of the average number of interferers, of the dynamic range of the interferers potentially capable of generating linear and non-linear distortion effects in the victim receiver, and of the outage probability. In many cases, the combined interference power at the receiver is shown to be dominated by the contribution of the strongest interferer. This analysis culminates in formulation of a tradeoff relationship between the network density and the outage probability. The positive role of linear filtering (e.g. in the antenna or in frequency filters of the receiver) in reducing the number and dynamic range of interfering signals, and/or in reducing the outage probability is quantified via a new statistical selectivity parameter (Q-parameter). The linear filtering allows increasing the network density by a factor of Q at the same outage probability

Computerized neurocognitive training for improving dietary health and facilitating weight loss

Nearly 70% of Americans are overweight, in large part because of overconsumption of high-calorie foods such as sweets. Reducing sweets is difficult because powerful drives toward reward overwhelm inhibitory control (i.e., the ability to withhold a prepotent response) capacities. Computerized inhibitory control trainings (ICTs) have shown positive outcomes, but impact on real-world health behavior has been variable, potentially because of limitations inherent in existing paradigms, e.g., low in frequency, intrinsic enjoyment, personalization, and ability to adapt to increasing ability. The present study aimed to assess the feasibility, acceptability, and efficacy of a gamified and non-gamified, daily, personalized, and adaptive ICT designed to facilitate weight loss by targeting consumption of sweets. Participants (N = 106) were randomized to one of four conditions in a 2 (gamified vs. non-gamified) by 2 (ICT vs. sham) factorial design. Participants were prescribed a no-added-sugar diet and completed 42 daily, at-home trainings, followed by two weekly booster trainings. Results indicated that the ICTs were feasible and acceptable. Surprisingly, compliance to the 44 trainings was excellent (88.8%) and equivalent across both gamified and non-gamified conditions. As hypothesized, the impact of ICT on weight loss was moderated by implicit preference for sweet foods [F(1,95) = 6.17, p = .02] such that only those with higher-than-average implicit preference benefited (8-week weight losses for ICT were 3.1% vs. 2.2% for sham). A marginally significant effect was observed for gamification to reduce the impact of ICT. Implications of findings for continued development of ICTs to impact health behavior are discussed

Channel Characteristics of MIMO-WLAN Communications at 60GHz for Various Corridors

[[abstract]]A comparison of 4 × 4 multiple-input multiple-output wireless local area network wireless communication characteristics for six different geometrical shapes is investigated. These six shapes include the straight shape corridor with rectangular cross section, the straight shape corridor with arched cross section, the curved shape corridor with rectangular cross section, the curved shape corridor with arched cross section, the L-shape corridor, and the T-shape corridor. The impulse responses of these corridors are computed by applying shooting and bouncing ray/image (SBR/Image) techniques along with inverse Fourier transform. By using the impulse response of these multipath channels, the mean excess delay, root mean square (RMS) delay spread for these six corridors can be obtained. Numerical results show that the capacity for the rectangular cross section corridors is smaller than those for the arched cross section corridors regardless of the shapes. And the RMS delay spreads for the T-and the L-shape corridors are greater than the other corridors.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子