Interference-Based Optimal Power-Efficient Access Scheme for Cognitive Radio Networks

In this paper, we propose a new optimization-based access strategy of multipacket reception (MPR) channel for multiple secondary users (SUs) accessing the primary user (PU) spectrum opportunistically. We devise an analytical model that realizes the multipacket access strategy of SUs that maximizes the throughput of individual backlogged SUs subject to queue stability of the PU. All the network receiving nodes have MPR capability. We aim at maximizing the throughput of the individual SUs such that the PU's queue is maintained stable. Moreover, we are interested in providing an energy-efficient cognitive scheme. Therefore, we include energy constraints on the PU and SU average transmitted energy to the optimization problem. Each SU accesses the medium with certain probability that depends on the PU's activity, i.e., active or inactive. The numerical results show the advantage in terms of SU throughput of the proposed scheme over the conventional access scheme, where the SUs access the channel randomly with fixed power when the PU is sensed to be idle

3D Camouflaging Object using RGB-D Sensors

This paper proposes a new optical camouflage system that uses RGB-D cameras, for acquiring point cloud of background scene, and tracking observers eyes. This system enables a user to conceal an object located behind a display that surrounded by 3D objects. If we considered here the tracked point of observer s eyes is a light source, the system will work on estimating shadow shape of the display device that falls on the objects in background. The system uses the 3d observer s eyes and the locations of display corners to predict their shadow points which have nearest neighbors in the constructed point cloud of background scene.Comment: 6 pages, 12 figures, 2017 IEEE International Conference on SM

A Comparison of SOR, ADI and Multigrid Methods for Solving Partial Differential Equations

This article presents several numerical techniques for solving Laplace equation. A numerical FORTRAN solver is developed to solve the 2D laplace equation. The numerical approaches implemented in the solver include Jacobi, Gauss-Siedel, Successive Over Relaxation, Alternating Direct Implicit and Multigrid methods. Detailed comparison between different numerical methods is presented and discusse

Investigating the Impact of COVID-19 on the Morale of Deaf and Hearing-Impaired Students in Saudi Arabia Technical Colleges: Lessons Learned and Future Implica-tions

Literature studies indicate that student morale has been affected during the Covid-19 pandemic. The COVID-19 pandemic has affected the mental health of people worldwide, and hard-of-hearing students may be particularly vulnerable. Researchers have well explained the relationship between stress, depression and anxiety between university students and COVID-19 pandemic. Indeed, many students had to follow their theoretical and practical courses remotely, using many programs and technologies, something that was not planned before. In addition, the containment measures applied by several countries during this period disrupted the school calendar and the normal course of university studies. Staying home for a long time period was not easy and caused students to ask many questions about their future studies. Most of the thoughts were negative, resulting in pessimistic feelings. This cross-sectional study aimed to determine the prevalence of depression, anxiety, and stress among hard-of-hearing students during the COVID-19 pandemic. In this work, we attempted to answer some questions by studying the application of two different tests to understand closely the impact of the COVID-19 pandemic on the moral status of deaf technical students in Saudi Arabia colleges. The goal is to extract the necessary lessons, tips and information that will protect this type of students in the future. Depression was slightly higher than anxiety and stress levels. The prevalence of depression was 56.2% for severe levels, while anxiety and stress levels had relatively lower severe cases of 45.2% and 49.3%, respectively. The study highlights the need to pay attention to the mental health of hard-of-hearing students during the COVID-19 pandemic and to provide appropriate support to manage their mental health