2,792 research outputs found
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
A multi-scale investigation of sediment and plastic pollution transport in the Tisza River applying remote sensing and machine learning: A hydrological perspective
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