2,439 research outputs found
Dynamic adaptation of streamed real-time E-learning videos over the internet
Even though the e-learning is becoming increasingly popular in the academic environment,
the quality of synchronous e-learning video is still substandard and significant work needs to be
done to improve it. The improvements have to be brought about taking into considerations both:
the network requirements and the psycho- physical aspects of the human visual system.
One of the problems of the synchronous e-learning video is that the head-and-shoulder video
of the instructor is mostly transmitted. This video presentation can be made more interesting by
transmitting shots from different angles and zooms. Unfortunately, the transmission of such
multi-shot videos will increase packet delay, jitter and other artifacts caused by frequent
changes of the scenes. To some extent these problems may be reduced by controlled reduction
of the quality of video so as to minimise uncontrolled corruption of the stream. Hence, there is a
need for controlled streaming of a multi-shot e-learning video in response to the changing
availability of the bandwidth, while utilising the available bandwidth to the maximum.
The quality of transmitted video can be improved by removing the redundant background
data and utilising the available bandwidth for sending high-resolution foreground information.
While a number of schemes exist to identify and remove the background from the foreground,
very few studies exist on the identification and separation of the two based on the understanding
of the human visual system. Research has been carried out to define foreground and background
in the context of e-learning video on the basis of human psychology. The results have been
utilised to propose methods for improving the transmission of e-learning videos.
In order to transmit the video sequence efficiently this research proposes the use of Feed-
Forward Controllers that dynamically characterise the ongoing scene and adjust the streaming
of video based on the availability of the bandwidth. In order to satisfy a number of receivers
connected by varied bandwidth links in a heterogeneous environment, the use of Multi-Layer
Feed-Forward Controller has been researched. This controller dynamically characterises the
complexity (number of Macroblocks per frame) of the ongoing video sequence and combines it
with the knowledge of availability of the bandwidth to various receivers to divide the video
sequence into layers in an optimal way before transmitting it into network.
The Single-layer Feed-Forward Controller inputs the complexity (Spatial Information and
Temporal Information) of the on-going video sequence along with the availability of bandwidth
to a receiver and adjusts the resolution and frame rate of individual scenes to transmit the
sequence optimised to give the most acceptable perceptual quality within the bandwidth
constraints.
The performance of the Feed-Forward Controllers have been evaluated under simulated
conditions and have been found to effectively regulate the streaming of real-time e-learning
videos in order to provide perceptually improved video quality within the constraints of the
available bandwidth
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Optimizing Quality for Collaborative Video Viewing
The increasing popularity of distance learning and online courses has highlighted the lack of collaborative tools for student groups. In addition, the introduction of lecture videos into the online curriculum has drawn attention to the disparity in the network resources used by the students. We present an architecture and adaptation model called AI2TV (Adaptive Internet Interactive Team Video), a system that allows geographically dispersed participants, possibly some or all disadvantaged in network resources, to collaboratively view a video in synchrony. AI2TV upholds the invariant that each participant will view semantically equivalent content at all times. Video player actions, like play, pause and stop, can be initiated by any of the participants and the results of those actions are seen by all the members. These features allow group members to review a lecture video in tandem to facilitate the learning process. We employ an autonomic (feedback loop) controller that monitors clients' video status and adjusts the quality of the video according to the resources of each client. We show in experimental trials that our system can successfully synchronize video for distributed clients while, at the same time, optimizing the video quality given actual (fluctuating) bandwidth by adaptively adjusting the quality level for each participant
Cognition-Based Networks: A New Perspective on Network Optimization Using Learning and Distributed Intelligence
IEEE Access
Volume 3, 2015, Article number 7217798, Pages 1512-1530
Open Access
Cognition-based networks: A new perspective on network optimization using learning and distributed intelligence (Article)
Zorzi, M.a , Zanella, A.a, Testolin, A.b, De Filippo De Grazia, M.b, Zorzi, M.bc
a Department of Information Engineering, University of Padua, Padua, Italy
b Department of General Psychology, University of Padua, Padua, Italy
c IRCCS San Camillo Foundation, Venice-Lido, Italy
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Abstract
In response to the new challenges in the design and operation of communication networks, and taking inspiration from how living beings deal with complexity and scalability, in this paper we introduce an innovative system concept called COgnition-BAsed NETworkS (COBANETS). The proposed approach develops around the systematic application of advanced machine learning techniques and, in particular, unsupervised deep learning and probabilistic generative models for system-wide learning, modeling, optimization, and data representation. Moreover, in COBANETS, we propose to combine this learning architecture with the emerging network virtualization paradigms, which make it possible to actuate automatic optimization and reconfiguration strategies at the system level, thus fully unleashing the potential of the learning approach. Compared with the past and current research efforts in this area, the technical approach outlined in this paper is deeply interdisciplinary and more comprehensive, calling for the synergic combination of expertise of computer scientists, communications and networking engineers, and cognitive scientists, with the ultimate aim of breaking new ground through a profound rethinking of how the modern understanding of cognition can be used in the management and optimization of telecommunication network
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