Video Conferencing Evaluation Considering Scalable Video Coding and SDN Network

Video conferencing is very common nowadays, and it may contemplate heterogenous devices (e.g., smartphones, notebooks, game consoles) and networks in the same session. Developing video conferencing systems for this myriad of devices with different capabilities requires special attention from system designer. Scalable video coding (SVC) is a prominent option to mitigate this heterogeneity issue, but traditional Internet protocol (IP) networks may not fully benefit from such a technology. In contrast, software-defined networking (SDN) may allow better utilization of SVC and improvements on video conferencing components. This paper evaluates the performance of video conferencing systems adopting SVC, SDN and ordinary IP networks, taking into account throughput, delay and peak signal-to-noise ratio (PSNR) as the metrics of interest. The experiments are based on Mininet framework and distinct network infrastructures are also considered. Results indicate SDN with SVC may deliver better video quality with reduced delay and increased throughput

Coded Wireless Video Broadcast/Multicast

Advancements in video coding, compact media display, and communication devices, particularly in emerging broadband wireless access networks, have created many foreseeable and exciting applications of video broadcast/multicast over the wireless meidum. For efficient and robust wireless video broadcast/multicast under fading, this thesis presents and examines a novel cross-layer framework that exploits the interplay between applying protections on a successively refinable video source and transmitting through a layered broadcast/multicast channel. The framework is realistically achieved and evaluated by using multiple description coding (MDC) on a scalable video source and using superposition coding (SPC) for layered broadcast/multicast transmissions. An analytical model using the total received/recovered video bitstreams from each coded wireless broadcast/multicast signal is developed, which serves as a metric of video quality for the system analysis and optimization. An efficient methodology has demonstrated that optimal power allocations and modulation selections can be practically determined to improve the broadcast/multicast video quality. From the information-theoretical perspective, a general closed-form formula is derived for the end-to-end distortion analysis of the proposed framework, which is applicable to any (n, k) protection code applied on a successive refinable source with a Gaussian distribution over layered Gaussian broadcast channels. The results reveal the scenarios for the proposed framework to lead to a lower distortion than a legacy system without any protection. By analyzing the characteristics of the closed-form formula, an efficient O(n log n) algorithm is developed to determine optimal k values in the (n, k) protection codes that minimize the distortion under the framework. Finally, a cross-layer design of logical SPC modulation is introduced to achieve layered broadcast/multicast for scalable video. It serves as an alternative for practically implementing the proposed framework of coded wireless video broadcast/multicast, if the hardware-based SPC component is not available in a wireless system. In summary, the thesis presents comprehensive analyses, simulations, and experiments to understand, investigate, and justify the effectiveness of the proposed cross-layer framework of coded wireless video broadcast/multicast. More importantly, this thesis contributes to the advancement in the related fields of communication engineering and information theory by introducing a new design dimension in terms of protection. This is unique when compared to previously-reported layered approaches that are often manipulating conventional parameters alone such as power and modulation scheme. The impact of this dimension was unapparent in the past, but is now proven as an effective means to enable high-quality, efficient, and robust wireless video broadcast/multicast for promising media applications

Task-based Adaptation of Graphical Content in Smart Visual Interfaces

To be effective visual representations must be adapted to their respective context of use, especially in so-called Smart Visual Interfaces striving to present specifically those information required for the task at hand. This thesis proposes a generic approach that facilitate the automatic generation of task-specific visual representations from suitable task descriptions. It is discussed how the approach is applied to four principal content types raster images, 2D vector and 3D graphics as well as data visualizations, and how existing display techniques can be integrated into the approach.Effektive visuelle Repräsentationen müssen an den jeweiligen Nutzungskontext angepasst sein, insbesondere in sog. Smart Visual Interfaces, welche anstreben, möglichst genau für die aktuelle Aufgabe benötigte Informationen anzubieten. Diese Arbeit entwirft einen generischen Ansatz zur automatischen Erzeugung aufgabenspezifischer Darstellungen anhand geeigneter Aufgabenbeschreibungen. Es wird gezeigt, wie dieser Ansatz auf vier grundlegende Inhaltstypen Rasterbilder, 2D-Vektor- und 3D-Grafik sowie Datenvisualisierungen anwendbar ist, und wie existierende Darstellungstechniken integrierbar sind

A university wide smart card system

Presently, many tertiary educational institutions utilise card technologies for staff and student identification and the support of other related services within the institution. A new type of card technology has been developed known as a Smart Card, where an existing plastic card has an embedded integrated circuit and is capable of expanding the range of applications and services capable within an institution. This thesis will detail the advantages that these new Smart Cards have over existing institution cards, detail other institution\u27s attempts to use Smart Cards and finally, this thesis proposes a suitable system for integrating Smart Cards into an existing tertiary educational institution

Class control: An adaptable and self configuring classroom control system

Class Control is a tool that was created at the University of St Andrews to allow a teacher to not only view all of the screens in a classroom at once but also take control of them and broadcast the teacher’s screen to them. Existing software wouldn’t allow the scalability to meet the demands of the size of the classroom so Class Control was developed and is still used by the school today.%0d%0aHowever, this tool was created to be used in one classroom just running the Mac OS. This thesis project aimed to add the ability to move this tool out of the classroom and be able to configure itself in a new classroom containing machines with other operating systems that can run Java.%0d%0aClass Control has now been extended to learn about a new environment it is in and use this information to help improve future runs of the tool. Previous configurations can be stored permitting a teacher to select a configuration that suits their needs and Class Control can also recommend a configuration depending on what clients it sees in the environment. Class Control can also be used to view and control Linux, Windows and Mac OS at the same time