Fuzzy logic congestion control for broadband wireless IPTV

All-IP broadband networks are being created with multimedia bandwidth requirements in mind. A unicast IPTV service forming a pipe or sub-channel on the converged network may need to negotiate a broadband wireless link. Where there is a need for multiple variable bit rate video streams to share the same pipe a problem of link utilisation arises [1], requiring congestion control at the server bank. Conventional controllers such as TCP-friendly rate control (TFRC) [2] and TCP emulation at receivers (TEAR) [3], originating in a TCP-dominated internet, will stream video up to the capacity of the pipe, but reacting to feedback may overestimate the capacity, resulting in packet loss, which leads to reduced video quality. In this Letter, fuzzy logic control (FLC) is shown to outperform conventional control in such a network by changing the quantisation parameter for live video or through a bit rate transcoder for pre-encoded video. Moreover, compared to prior use of traditional (type-1) fuzzy logic for similar purposes [4], interval type-2 (IT2) FLC has been employed, as this is robust to feedback measurement uncertainties.     

Measurement of scene-dependent quality variations in digitallycoded television pictures

Experiments are reported in which the ITU-R Double Stimulus Continuous Quality Scale (DSCQS) method was used to assess scene-dependent, time-varying television picture coding distortions introduced by MPEG-2 coding, at bit rates ranging from 1 Mbit/s to 7.5 Mbit/s. Test sequence lengths of both 10 s and 30 s were employed, the latter in an attempt to present to subjects a more representative range of quality variations, which were found to be large. In forming quality judgements of 30 s sequences, subjects gave significantly more weight to impairments occurring towards the end of the sequence; for identical impairments in the first and in the last 10 s of such a sequence, the difference in rating was typically about half a scale point on a 5-point scale. This recency effect is probably linked to the short-term nature of human working memory     

On the achievable rate bounds in multi-pair massive antenna relaying with correlated antennas

Wireless Networks - The issue of antenna correlation in multi-pair massive antenna relay network is studied. Under the spatial correlation properties of the channel, an analytical approximation for...     

Study of Extensive and Nonextensive Entropy of RbCl Quantum Well Qubit in an Asymmetric Gaussian Potential

Journal of Low Temperature Physics - We have presented extensive and nonextensive entropy of RbCl quantum well qubits (QWQ). To this end, we have considered an electron that is coupled to the...     

Effect of Resonant Helical Field (RHF) on Runaway Electrons in Tokamaks

The high energy current of runaway electrons during a major disruption in tokamak reactors can cause serious damage to the first wall of the reactor and reduce its life time. Therefore, finding a method to minimize runaway electron is much needed. Resonant helical field (RHF) is one of the methods for controlling the magnetohydrodynamic (MHD) activity. This paper attempts to examine the effect of RHF on the generation of runaway electrons. Main parameters such as plasma current, loop voltage, emitted hard X-ray intensity, MHD oscillation, H_α radiation and MHD activity modes, in the presence and absence of RHF (L = 2 and L = 3), were measured. The results show that applying this system can change runaway electrons generation.     

Maximal atom–photon entanglement in a double-$$\Lambda $$ quantum system

The atom–photon entanglement of a dressed atom and its spontaneous emission in a double-\(\Lambda \) closed-loop atomic system is studied under multi-photon resonance condition. It is shown that even in the absence of quantum interference due to the spontaneous emission, the von Neumann entropy is phase-sensitive and it can be controlled by either intensity or relative phase of the applied fields. It is demonstrated that for the special case of Rabi frequency of the applied fields, the system is maximally entangled. Moreover, an open-loop configuration is considered, and it is shown that the degree of entanglement can be controlled by intensity of the applied fields. Furthermore, in electromagnetically induced transparency condition, the system is disentangled. Such a system can be used for quantum information processing via entanglement using optical switching.     

Synthesis and evaluation of biological activities of 4-cyclopropyl-5-(2-fluorophenyl) arylhydrazono-2,3-dihydrothiazoles as potent antioxidant agents

A new series of 4-cyclopropyl-5-(2-fluorophenyl)arylhydrazono-2,3-dihydrothiazole derivatives was synthesized via the reaction of prepared thiosemicarbazones with 2-bromo-1-cyclopropyl-2-(2-?uorophenyl)ethanone in the presence of Et₃N as a catalyst through a semi Hantzsch cyclization. The optimized reaction conditions for this one-pot reaction were achieved. The products were obtained in short reaction times, high yields and high purities. Antioxidant activity of products was evaluated using DPPH (2,2-diphenyl-2-picrylhydrazyl) and ABTS 2,2-azinobis(3-ethylbenzothiazoline-sulfonate) assays. Products showed higher antioxidant activity using the ABTS method. Compounds 5c and 5g showed lower IC₅₀ values compared with ascorbic acid as a standard. Compounds 5a–5h possessed moderate to high antioxidant activity by both methods. Also, antibacterial activity of 5a–5h was evaluated against gram-positive and gram-negative bacterial strains. None of the compounds inhibited A. hydrophila, while they had moderate to low inhibitory activity against other tested bacterial strains.