A Novel Handoff Prioritization Scheme Based on Propagation and Traffic Criteria

In this paper, in order to modify and improve the handoff process, which contains initiation and execution phases, three new prioritization schemes have been investigated. These new schemes prioritize handoff requests considering both traffic and propagation conditions. According to suggested schemes, priority of different candidate base-stations is based on three measurements in a joint state. These measurements are received power at mobile unit, power variation rates, and the number of free traffic channels of adjacent base-stations. Simulation results show that considering similar conditions, i.e. equal number of handoffs, lower call dropping (outage) and smaller delay distance will be achieved by new prioritization schemes rather than previous works. It means access to lower forced termination probability and interference and hence better QoS (Quality of Service). Finally, due to the best trade offs between propagation and traffic criteria, simulation results introduce SPBPS3 as optimum scheme

The galaxy environment in GAMA G3C groups using the Kilo Degree Survey Data Release 3

We aim to investigate the galaxy environment in GAMA Galaxy Groups Catalogue (G3C) using a volume-limited galaxy sample from the Kilo Degree Survey Data Release 3. The k-Nearest Neighbour technique is adapted to take into account the probability density functions (PDFs) of photometric redshifts in our calculations. This algorithm was tested on simulated KiDS tiles, showing its capability of recovering the relation between galaxy colour, luminosity and local environment. The characterization of the galaxy environment in G3C groups shows systematically steeper density contrasts for more massive groups. The red galaxy fraction gradients in these groups is evident for most of group mass bins. The density contrast of red galaxies is systematically higher at group centers when compared to blue galaxy ones. In addition, distinct group center definitions are used to show that our results are insensitive to center definitions. These results confirm the galaxy evolution scenario which environmental mechanisms are responsible for a slow quenching process as galaxies fall into groups and clusters, resulting in a smooth observed colour gradients in galaxy systems.Comment: 14 pages, Accepted to MNRA

F(T) Models within Bianchi Type I Universe

In this paper, we consider spatially homogenous and anisotropic Bianchi type I universe in the context of F(T) gravity. We construct some corresponding models using conservation equation and equation of state parameter representing different phases of the universe. In particular, we take matter dominated era, radiation dominated era, present dark energy phase and their combinations. It is found that one of the models has a constant solution which may correspond to the cosmological constant. We also derive equation of state parameter by using two well-known F(T) models and discuss cosmic acceleration.Comment: 19 pages, accepted for publication in Mod. Phys. Lett.

Horizon Problem Remediation via Deformed Phase Space

We investigate the effects of a special kind of dynamical deformation between the momenta of the scalar field of the Brans-Dicke theory and the scale factor of the FRW metric. This special choice of deformation includes linearly a deformation parameter. We trace the deformation footprints in the cosmological equations of motion when the BD coupling parameter goes to infinity. One class of the solutions gives a constant scale factor in the late time that confirms the previous result obtained via another approach in the literature. This effect can be interpreted as a quantum gravity footprint in the coarse grained explanation. The another class of the solutions removes the big bang singularity, and the accelerating expansion region has an infinite temporal range which overcomes the horizon problem. After this epoch, there is a graceful exiting by which the universe enters in the radiation dominated era.Comment: 13 pages, 2 figures, to appear in GER