3,581 research outputs found
OSCAR: A Collaborative Bandwidth Aggregation System
The exponential increase in mobile data demand, coupled with growing user
expectation to be connected in all places at all times, have introduced novel
challenges for researchers to address. Fortunately, the wide spread deployment
of various network technologies and the increased adoption of multi-interface
enabled devices have enabled researchers to develop solutions for those
challenges. Such solutions aim to exploit available interfaces on such devices
in both solitary and collaborative forms. These solutions, however, have faced
a steep deployment barrier.
In this paper, we present OSCAR, a multi-objective, incentive-based,
collaborative, and deployable bandwidth aggregation system. We present the
OSCAR architecture that does not introduce any intermediate hardware nor
require changes to current applications or legacy servers. The OSCAR
architecture is designed to automatically estimate the system's context,
dynamically schedule various connections and/or packets to different
interfaces, be backwards compatible with the current Internet architecture, and
provide the user with incentives for collaboration. We also formulate the OSCAR
scheduler as a multi-objective, multi-modal scheduler that maximizes system
throughput while minimizing energy consumption or financial cost. We evaluate
OSCAR via implementation on Linux, as well as via simulation, and compare our
results to the current optimal achievable throughput, cost, and energy
consumption. Our evaluation shows that, in the throughput maximization mode, we
provide up to 150% enhancement in throughput compared to current operating
systems, without any changes to legacy servers. Moreover, this performance gain
further increases with the availability of connection resume-supporting, or
OSCAR-enabled servers, reaching the maximum achievable upper-bound throughput
A Constructivist Grounded Theory Investigation of Businesses’ Concerns About Public-Private Partnership Responses Toward COVID-19
Peripheral destinations in Egypt face public-private partnership (P3) response challenges during COVID-19. The proposed partnership policies and solutions of governments seem inadequate and reflect a lack of agility. This constructivist grounded theory (GT) study aims to investigate businesses’ perceptions and concerns that may affect reshaping the P3 strategies of Egypt’s tourism-related government departments at Marsa Alam, Egypt. The period under investigation is May 2020 to July 2020, when COVID-19 was causing a fundamental change in Egypt’s tourism industry. The findings show that employees’ rights, businesses’ priorities, destina tions’ recovery challenges, and making P3 more joined-up are significant concerns in the recovery, restart, and agile P3 responses of peripheral destinations. This study investigates P3 management and considers its application in the wake of global health crises, where agile P3 practices are lacking
Innovative techniques for seismic-resistant bridge columns under ground motion excitations
“This dissertation provides innovative alternative solutions for replacing conventional reinforced concrete columns. The proposed columns displayed enhanced seismic resistance and properties compared to their counterpart conventional columns. Two main techniques were followed and proposed to develop seismic-resistant columns. The first technique utilized rubberized concrete to internally enhance energy dissipation and damping. Materials testing of rubberized concrete with scrap tire replacement of fine aggregates were performed to evaluate its dynamic properties. Shaking table testing of a rubberized concrete column was performed and the behavior was compared to that of the conventional one. The rubberized column showed an increase of 16% in energy dissipation compared to the conventional column. This solution also had the benefit of using recycled tire rubber, which produced green concrete. The second technique utilized post-tensioned segmental columns with double-skin cross section and external energy dissipaters. Three columns with different configurations were tested on the shaking table and compared with the conventional column. These columns outperformed the conventional column; especially regarding the residual drift. The peak drift for the posttensioned columns was 8.85% with a residual drift of 0.08% compared to 4.8% peak drift with 1.5% residual drift for the conventional column. Three-dimensional finite element models for the post-tensioned columns were developed using LS-DYNA software. The effects of ground motion characteristics including far-field motions, near-fault motions without forward-directivity, near-fault motions with forward-directivity, and near-fault motions with fling-step on full-scale column models were investigated. An analytical model for the design of post-tensioned columns was provided”--Abstract, page iv
Unconventional TV Detection using Mobile Devices
Recent studies show that the TV viewing experience is changing giving the
rise of trends like "multi-screen viewing" and "connected viewers". These
trends describe TV viewers that use mobile devices (e.g. tablets and smart
phones) while watching TV. In this paper, we exploit the context information
available from the ubiquitous mobile devices to detect the presence of TVs and
track the media being viewed. Our approach leverages the array of sensors
available in modern mobile devices, e.g. cameras and microphones, to detect the
location of TV sets, their state (ON or OFF), and the channels they are
currently tuned to. We present the feasibility of the proposed sensing
technique using our implementation on Android phones with different realistic
scenarios. Our results show that in a controlled environment a detection
accuracy of 0.978 F-measure could be achieved.Comment: 4 pages, 14 figure
USCID fifth international conference
Presented at the fifth international conference on irrigation and drainage, Irrigation and drainage for food, energy and the environment on November 3-6, 2009 in Salt Lake City, Utah.Includes bibliographical references.Optimal management of irrigation systems and their efficient use of energy is a major global concern where energy resources are jeopardized. Effective solar irradiance in the United Arab Emirates is available most of the year which makes it easy to project PV (Photo Voltaic) system output and the produced flow and pressure produced by a PV-powered DC pump. A PV- irrigation system was developed in the experimental farm of the College of Food and Agriculture, United Arab Emirates University. In this paper an adaptive scheduling scheme is developed to provide an adaptive control of a photovoltaic powered irrigation system according to the availability of solar energy as well as the field conditions of the irrigated zones. Simulation of the PV irrigation system including PV module, pump and irrigation network is carried out using Matlab™ to predict power output using historical data, and water application rates accordingly. An executive irrigation schedule is also developed utilizing direct weather data from weather station to implement unexpected variation in weather conditions and field water requirements as well
Levodopa Enhances Reward Learning but Impairs Reversal Learning in Parkinson's Disease Patients
A commentary on Differential influence of levodopa on reward-based learning in Parkinson’s disease
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