Coverage and Rate Analysis for Unmanned Aerial Vehicle Base Stations with LoS/NLoS Propagation

The use of unmanned aerial vehicle base stations (UAV-BSs) as airborne base stations has recently gained great attention. In this paper, we model a network of UAV-BSs as a Poisson point process (PPP) operating at a certain altitude above the ground users. We adopt an air-to-ground (A2G) channel model that incorporates line-of-sight (LoS) and non-line-of-sight (NLoS) propagation. Thus, UAV-BSs can be decomposed into two independent inhomogeneous PPPs. Under the assumption that NLoS and LoS channels experience Rayleigh and Nakagami-m fading, respectively, we derive approximations for the coverage probability and average achievable rate, and show that these approximations match the simulations with negligible errors. Numerical simulations have shown that the coverage probability and average achievable rate decrease as the height of the UAV-BSs increases

3D Placement of an Unmanned Aerial Vehicle Base Station (UAV-BS) for Energy-Efficient Maximal Coverage

Unmanned Aerial Vehicle mounted base stations (UAV-BSs) can provide wireless services in a variety of scenarios. In this letter, we propose an optimal placement algorithm for UAV-BSs that maximizes the number of covered users using the minimum transmit power. We decouple the UAV-BS deployment problem in the vertical and horizontal dimensions without any loss of optimality. Furthermore, we model the UAV-BS deployment in the horizontal dimension as a circle placement problem and a smallest enclosing circle problem. Simulations are conducted to evaluate the performance of the proposed method for different spatial distributions of the users

Voltage-induced strain control of the magnetic anisotropy in a Ni thin film on flexible substrate

Voltage-induced magnetic anisotropy has been quantitatively studied in polycrystalline Ni thin film deposited on flexible substrate using microstrip ferromagnetic resonance. This anisotropy is induced by a piezoelectric actuator on which the film/substrate system was glued. In our work, the control of the anisotropy through the applied elastic strains is facilitated by the compliant elastic behavior of the substrate. The in-plane strains in the film induced by the piezoelectric actuation have been measured by the digital image correlation technique. Non-linear variation of the resonance field as function of the applied voltage is found and well reproduced by taking into account the non linear and hysteretic variations of the induced in-plane strains as function of the applied voltage. Moreover, we show that initial uniaxial anisotropy attributed to compliant substrate curvature is fully compensated by the voltage induced anisotropy.Comment: 7 pages, 6 figures, published in the Journal of Applied Physic

Sustainable Food Consumption: Theory of Planned Behavior – The Case of Low Income Group in Penang, Malaysia.

Kemiskinan dan kemerosotan kuality alam sekitar sangat berkait rapat. Walaupun kemiskinan adalah salah satu penyebabkan kemorosotan alam sekitar tetapi masalah utama adalah disebabkan oleh pembelian dan penggunaan secara tidak lestari, terutama di negara perindustrian. Poverty and environmental degradation are closely interrelated. While poverty results in certain kinds of environmental stress, the major cause of the continued deterioration of the global environment is the unsustainable pattern of consumption and production, particularly in industrialized countrie

The right to live and die / Abdul Halim Mohamed Dalib

'The Right to Live and Die t is a topic which is very controversial and sensitive ill nature, as the core of the discussion centres around the question of life and death, particularly the rights of an individual over his own life and death. The areas within the framework of this topic is extensive, and the writer therefore decided to limit the discussion to three important issues, that is, pertaining to Suicide, Euthanasia and Abortion, as discussed in Chapter 1, 2 and 3 respectively

From the Mahdiyya to the Salvation : women's rights in the Sudanese laws

This paper is part of ongoing research I am conducting into the legal system in the Sudan. It is an attempt to understand if it is the absence of the rule of law that is at the core of the wave of violence against women both within and outside of the conflict zones in the Sudan. Much of this paper centres on the historical eras of the Mahdiyya and the Condominium