5,991 research outputs found
An information assistant system for the prevention of tunnel vision in crisis management
In the crisis management environment, tunnel vision is a set of bias in decision makers’ cognitive process which often leads to incorrect understanding of the real crisis situation, biased perception of information, and improper decisions. The tunnel vision phenomenon is a consequence of both the challenges in the task and the natural limitation in a human being’s cognitive process. An information assistant system is proposed with the purpose of preventing tunnel vision. The system serves as a platform for monitoring the on-going crisis event. All information goes through the system before arrives at the user. The system enhances the data quality, reduces the data quantity and presents the crisis information in a manner that prevents or repairs the user’s cognitive overload. While working with such a system, the users (crisis managers) are expected to be more likely to stay aware of the actual situation, stay open minded to possibilities, and make proper decisions
Supporting multimedia user interface design using mental models and representational expressiveness
This thesis addresses the problem of output media allocation in the design of
multimedia user interfaces. The literature survey identifies a formal definition of the
representational capabilities of different media.as important in this task. Equally
important, though less prominent in the literature, is that the correct mental model of
a domain is paramount for the successful completion of tasks.
The thesis proposes an original linguistic and cognitive based descriptive framework,
in two parts. The first part defines expressiveness, the amount of representational
abstraction a medium provides over any domain. The second part describes how this
expressiveness is linked to the mental models that media induce, and how this in turn
affects task performance. It is postulated that the mental models induced by different
media, will reflect the abstractive representation those media offer over the task
domain. This must then be matched to the abstraction required by tasks to allow them
to be effectively accomplished.
A 34 subject experiment compares five media, of two levels of expressiveness, over a
range of tasks, in a complex and dynamic domain. The results indicate that
expressiveness may allow media to be matched more closely to tasks, if the mental
models they are known to induce are considered.
Finally, the thesis proposes a tentative framework for media allocation, and two
example interfaces are designed using this framework. This framework is based on
the matching of expressiveness to the abstraction of a domain required by tasks. The
need for the methodology to take account of the user's cognitive capabilities is
stressed, and the experimental results are seen as the beginning of this procedure
Video browsing interfaces and applications: a review
We present a comprehensive review of the state of the art in video browsing and retrieval systems, with special emphasis on interfaces and applications. There has been a significant increase in activity (e.g., storage, retrieval, and sharing) employing video data in the past decade, both for personal and professional use. The ever-growing amount of video content available for human consumption and the inherent characteristics of video data—which, if presented in its raw format, is rather unwieldy and costly—have become driving forces for the development of more effective solutions to present video contents and allow rich user interaction. As a result, there are many contemporary research efforts toward developing better video browsing solutions, which we summarize. We review more than 40 different video browsing and retrieval interfaces and classify them into three groups: applications that use video-player-like interaction, video retrieval applications, and browsing solutions based on video surrogates. For each category, we present a summary of existing work, highlight the technical aspects of each solution, and compare them against each other
Enhancing QoS and QoE in IMS Enabled Next Generation Networks
Managing network complexity, accommodating greater numbers of subscribers,
improving coverage to support data services (e.g. email, video, and music
downloads), keeping up to speed with fast-changing technology, and driving
maximum value from existing networks - all while reducing CapEX and OpEX and
ensuring Quality of Service (QoS) for the network and Quality of Experience
(QoE) for the user. These are just some of the pressing business issues faced
by mobileservice providers, summarized by the demand to "achieve more, for
less." The ultimate goal of optimization techniques at the network and
application layer is to ensure End-user perceived QoS. The next generation
networks (NGN), a composite environment of proven telecommunications and
Internet-oriented mechanisms have become generally recognized as the
telecommunications environment of the future. However, the nature of the NGN
environment presents several complex issues regarding quality assurance that
have not existed in the legacy environments (e.g., multi-network, multi-vendor,
and multi-operator IP-based telecommunications environment, distributed
intelligence, third-party provisioning, fixed-wireless and mobile access,
etc.). In this Research Paper, a service aware policy-based approach to NGN
quality assurance is presented, taking into account both perceptual quality of
experience and technologydependant quality of service issues. The respective
procedures, entities, mechanisms, and profiles are discussed. The purpose of
the presented approach is in research, development, and discussion of pursuing
the end-to-end controllability of the quality of the multimedia NGN-based
communications in an environment that is best effort in its nature and promotes
end user's access agnosticism, service agility, and global mobility.Comment: 11 Page
The Design of a System Architecture for Mobile Multimedia Computers
This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies
Resource Allocation in 4G and 5G Networks: A Review
The advent of 4G and 5G broadband wireless networks brings several challenges with respect to resource allocation in the networks. In an interconnected network of wireless devices, users, and devices, all compete for scarce resources which further emphasizes the fair and efficient allocation of those resources for the proper functioning of the networks. The purpose of this study is to discover the different factors that are involved in resource allocation in 4G and 5G networks. The methodology used was an empirical study using qualitative techniques by performing literature reviews on the state of art in 4G and 5G networks, analyze their respective architectures and resource allocation mechanisms, discover parameters, criteria and provide recommendations. It was observed that resource allocation is primarily done with radio resource in 4G and 5G networks, owing to their wireless nature, and resource allocation is measured in terms of delay, fairness, packet loss ratio, spectral efficiency, and throughput. Minimal consideration is given to other resources along the end-to-end 4G and 5G network architectures. This paper defines more types of resources, such as electrical energy, processor cycles and memory space, along end-to-end architectures, whose allocation processes need to be emphasized owing to the inclusion of software defined networking and network function virtualization in 5G network architectures. Thus, more criteria, such as electrical energy usage, processor cycle, and memory to evaluate resource allocation have been proposed. Finally, ten recommendations have been made to enhance resource allocation along the whole 5G network architecture
Application of service composition mechanisms to Future Networks architectures and Smart Grids
Aquesta tesi gira entorn de la hipòtesi de la metodologia i mecanismes de composiciĂł de serveis i com es poden aplicar a diferents camps d'aplicaciĂł per a orquestrar de manera eficient comunicacions i processos flexibles i sensibles al context. MĂ©s concretament, se centra en dos camps d'aplicaciĂł: la distribuciĂł eficient i sensible al context de contingut multimèdia i els serveis d'una xarxa elèctrica intel·ligent. En aquest Ăşltim camp es centra en la gestiĂł de la infraestructura, cap a la definiciĂł d'una Software Defined Utility (SDU), que proposa una nova manera de gestionar la Smart Grid amb un enfocament basat en programari, que permeti un funcionament molt mĂ©s flexible de la infraestructura de xarxa elèctrica. Per tant, revisa el context, els requisits i els reptes, aixĂ com els enfocaments de la composiciĂł de serveis per a aquests camps. Fa especial èmfasi en la combinaciĂł de la composiciĂł de serveis amb arquitectures Future Network (FN), presentant una proposta de FN orientada a serveis per crear comunicacions adaptades i sota demanda. TambĂ© es presenten metodologies i mecanismes de composiciĂł de serveis per operar sobre aquesta arquitectura, i posteriorment, es proposa el seu Ăşs (en conjunciĂł o no amb l'arquitectura FN) en els dos camps d'estudi. Finalment, es presenta la investigaciĂł i desenvolupament realitzat en l'Ă mbit de les xarxes intel·ligents, proposant diverses parts de la infraestructura SDU amb exemples d'aplicaciĂł de composiciĂł de serveis per dissenyar seguretat dinĂ mica i flexible o l'orquestraciĂł i gestiĂł de serveis i recursos dins la infraestructura de l'empresa elèctrica.Esta tesis gira en torno a la hipĂłtesis de la metodologĂa y mecanismos de composiciĂłn de servicios y cĂłmo se pueden aplicar a diferentes campos de aplicaciĂłn para orquestar de manera eficiente comunicaciones y procesos flexibles y sensibles al contexto. Más concretamente, se centra en dos campos de aplicaciĂłn: la distribuciĂłn eficiente y sensible al contexto de contenido multimedia y los servicios de una red elĂ©ctrica inteligente. En este Ăşltimo campo se centra en la gestiĂłn de la infraestructura, hacia la definiciĂłn de una Software Defined Utility (SDU), que propone una nueva forma de gestionar la Smart Grid con un enfoque basado en software, que permita un funcionamiento mucho más flexible de la infraestructura de red elĂ©ctrica. Por lo tanto, revisa el contexto, los requisitos y los retos, asĂ como los enfoques de la composiciĂłn de servicios para estos campos. Hace especial hincapiĂ© en la combinaciĂłn de la composiciĂłn de servicios con arquitecturas Future Network (FN), presentando una propuesta de FN orientada a servicios para crear comunicaciones adaptadas y bajo demanda. TambiĂ©n se presentan metodologĂas y mecanismos de composiciĂłn de servicios para operar sobre esta arquitectura, y posteriormente, se propone su uso (en conjunciĂłn o no con la arquitectura FN) en los dos campos de estudio. Por Ăşltimo, se presenta la investigaciĂłn y desarrollo realizado en el ámbito de las redes inteligentes, proponiendo varias partes de la infraestructura SDU con ejemplos de aplicaciĂłn de composiciĂłn de servicios para diseñar seguridad dinámica y flexible o la orquestaciĂłn y gestiĂłn de servicios y recursos dentro de la infraestructura de la empresa elĂ©ctrica.This thesis revolves around the hypothesis the service composition methodology and mechanisms and how they can be applied to different fields of application in order to efficiently orchestrate flexible and context-aware communications and processes. More concretely, it focuses on two fields of application that are the context-aware media distribution and smart grid services and infrastructure management, towards a definition of a Software-Defined Utility (SDU), which proposes a new way of managing the Smart Grid following a software-based approach that enable a much more flexible operation of the power infrastructure. Hence, it reviews the context, requirements and challenges of these fields, as well as the service composition approaches. It makes special emphasis on the combination of service composition with Future Network (FN) architectures, presenting a service-oriented FN proposal for creating context-aware on-demand communication services. Service composition methodology and mechanisms are also presented in order to operate over this architecture, and afterwards, proposed for their usage (in conjunction or not with the FN architecture) in the deployment of context-aware media distribution and Smart Grids. Finally, the research and development done in the field of Smart Grids is depicted, proposing several parts of the SDU infrastructure, with examples of service composition application for designing dynamic and flexible security for smart metering or the orchestration and management of services and data resources within the utility infrastructure
QoE-Centric Control and Management of Multimedia Services in Software Defined and Virtualized Networks
Multimedia services consumption has increased tremendously since the deployment of 4G/LTE networks. Mobile video services (e.g., YouTube and Mobile TV) on smart devices are expected to continue to grow with the emergence and evolution of future networks such as 5G. The end user’s demand for services with better quality from service providers has triggered a trend towards Quality of Experience (QoE) - centric network management through efficient utilization of network resources. However, existing network technologies are either unable to adapt to diverse changing network conditions or limited in available resources.
This has posed challenges to service providers for provisioning of QoE-centric multimedia services. New networking solutions such as Software Defined Networking (SDN) and Network Function Virtualization (NFV) can provide better solutions in terms of
QoE control and management of multimedia services in emerging and future networks. The features of SDN, such as adaptability, programmability and cost-effectiveness make it suitable for bandwidth-intensive multimedia applications such as live video streaming, 3D/HD video and video gaming. However, the delivery of multimedia services over SDN/NFV networks to achieve optimized QoE, and the overall QoE-centric network resource management remain an open question especially in the advent development of future softwarized networks.
The work in this thesis intends to investigate, design and develop novel approaches for QoE-centric control and management of multimedia services (with a focus on video streaming services) over software defined and virtualized networks.
First, a video quality management scheme based on the traffic intensity under Dynamic Adaptive Video Streaming over HTTP (DASH) using SDN is developed. The proposed scheme can mitigate virtual port queue congestion which may cause
buffering or stalling events during video streaming, thus, reducing the video quality.
A QoE-driven resource allocation mechanism is designed and developed for improving the end user’s QoE for video streaming services. The aim of this approach is to find the best combination of network node functions that can provide an optimized QoE level to end-users through network node cooperation. Furthermore, a novel QoE-centric management scheme is proposed and developed, which utilizes Multipath TCP (MPTCP) and Segment Routing (SR) to enhance QoE for video streaming services over SDN/NFV-based networks. The goal of this strategy is to enable service providers to route network traffic through multiple
disjointed bandwidth-satisfying paths and meet specific service QoE guarantees to the end-users. Extensive experiments demonstrated that the proposed schemes in this work improve the video quality significantly compared with the state-of-the-
art approaches. The thesis further proposes the path protections and link failure-free MPTCP/SR-based architecture that increases survivability, resilience, availability and robustness of future networks. The proposed path protection and dynamic link recovery scheme achieves a minimum time to recover from a failed link and avoids link congestion in softwarized networks
An Architecture for distributed multimedia database systems
In the past few years considerable demand for user oriented multimedia information systems has developed. These systems must provide a rich set of functionality so that new, complex, and interesting applications can be addressed. This places considerable importance on the management of diverse data types including text, images, audio and video. These requirements generate the need for a new generation of distributed heterogeneous multimedia database systems. In this paper we identify a set of functional requirements for a multimedia server considering database management, object synchronization and integration, and multimedia query processing. A generalization of the requirements to a distributed system is presented, and some of our current research and developing activities are discussed
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