Experimental Verification of a Radio-Frequency Power Model for Wi-Fi Technology

When assessing the power emitted from a Wi-Fi network, it has been observed that these networks operate at a relatively low duty cycle. In this paper, we extend a recently introduced model of emitted power in Wi-Fi networks to cover conditions where devices do not always have packets to transmit. We present experimental results to validate the original model and its extension by developing approximate, but practical, testbed measurement techniques. The accuracy of the models is confirmed, with small relativ

Decentralised Learning MACs for Collision-free Access in WLANs

By combining the features of CSMA and TDMA, fully decentralised WLAN MAC schemes have recently been proposed that converge to collision-free schedules. In this paper we describe a MAC with optimal long-run throughput that is almost decentralised. We then design two \changed{schemes} that are practically realisable, decentralised approximations of this optimal scheme and operate with different amounts of sensing information. We achieve this by (1) introducing learning algorithms that can substantially speed up convergence to collision free operation; (2) developing a decentralised schedule length adaptation scheme that provides long-run fair (uniform) access to the medium while maintaining collision-free access for arbitrary numbers of stations

Globally, songs and instrumental melodies are slower, higher, and use more stable pitches than speech: a registered report

Both music and language are found in all known human societies, yet no studies have compared similarities and differences between song, speech, and instrumental music on a global scale. In this Registered Report, we analyzed two global datasets: (i) 300 annotated audio recordings representing matched sets of traditional songs, recited lyrics, conversational speech, and instrumental melodies from our 75 coauthors speaking 55 languages; and (ii) 418 previously published adult-directed song and speech recordings from 209 individuals speaking 16 languages. Of our six preregistered predictions, five were strongly supported: Relative to speech, songs use (i) higher pitch, (ii) slower temporal rate, and (iii) more stable pitches, while both songs and speech used similar (iv) pitch interval size and (v) timbral brightness. Exploratory analyses suggest that features vary along a “musi-linguistic” continuum when including instrumental melodies and recited lyrics. Our study provides strong empirical evidence of cross-cultural regularities in music and speech

Power Evaluation and Performance Enhancement of CSMA/CA based WLANs

Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) based Wireless Local Area Networks (WLANs) are becoming pervasive. As the most commonly employed standard in WLANs, IEEE 802.11 not only gives rise to health and safety concern from the general public, but also has the potential for enhanced performance. Our contributions in this thesis are twofold: (1) We extend a recently introduced model of transmitted power in WLANs to cover unsaturated conditions when stations do not always have packets to send. we implement an experimental verification of the original analytic model and the extended one. We confirm the estimated maximum power is substantially lower than the International Commission on Non-Ionizing Radiation Protection (ICNIRP) limit; (2) We propose two decentralized Multiple Access Control (MAC) schemes that converge to collision-free schedules almost surely and therefore improve throughput performance. In adopting decentralized learning techniques, the convergence times of both schemes are brief. Decentralized schedule length adaption is introduced to provide long-run fair access to the medium and scalability of the MAC schemes to networks of any size

Experimental Verification of a Radio-Frequency Power Model for Wi-Fi Technology

When assessing the power emitted from a Wi-Fi network, it has been observed that these networks operate at a relatively low duty cycle. In this paper, we extend a recently introduced model of emitted power in Wi-Fi networks to cover conditions where devices do not always have packets to transmit. We present experimental results to validate the original model and its extension by developing approximate, but practical, testbed measurement techniques. The accuracy of the models is confirmed, with small relativ

Experimental Verification of a Radio-Frequency Power Model for Wi-Fi Technology

When assessing the power emitted from a Wi-Fi network, it has been observed that these networks operate at a relatively low duty cycle. In this paper, we extend a recently introduced model of emitted power in Wi-Fi networks to cover conditions where devices do not always have packets to transmit. We present experimental results to validate the original model and its extension by developing approximate, but practical, testbed measurement techniques. The accuracy of the models is confirmed, with small relativ

Experimental Verification of a Radio-Frequency Power Model for Wi-Fi Technology

When assessing the power emitted from a Wi-Fi network, it has been observed that these networks operate at a relatively low duty cycle. In this paper, we extend a recently introduced model of emitted power in Wi-Fi networks to cover conditions where devices do not always have packets to transmit. We present experimental results to validate the original model and its extension by developing approximate, but practical, testbed measurement techniques. The accuracy of the models is confirmed, with small relativ

Low-firing and temperature stable microwave dielectric ceramics: Ba2LnV3O11 (Ln = Nd, Sm)

Low-firing and temperature stable microwave dielectric ceramics of Ba2LnV3O11 (Ln = Nd, Sm) were prepared by solid-state reaction. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the phase purity, crystal structure, sintering behavior, and microstructure. The XRD patterns indicated that Ba2LnV3O11 (Ln =Nd, Sm) ceramics belong to monoclinic crystal system with P21/c space group in the whole sintering temperature range (800-900 °C). Both ceramics could be well densified at 880 °C for 4 h with relative densities higher than 96%. The Ba2LnV3O11 (Ln =Nd, Sm) samples sintered at 880 °C for 4 h exhibited excellent microwave dielectric properties: εr = 12.05, Q×f = 23,010 GHz, τf = –7.7 ppm/oC, and εr = 12.19, Q×f = 27,120 GHz, τf = –16.2 ppm/oC, respectively. Besides, Ba2LnV3O11 (Ln =Nd, Sm) ceramics could be well co-fired with the silver electrode at 880 °C