250 research outputs found
WEST: A Web Browser for Small Terminals
We describe WEST, a WEb browser for Small Terminals, that aims to solve some of the problems associated with accessing web pages on hand-held devices. Through a novel combination of text reduction and focus+context visualization, users can access web pages from a very limited display environment, since the system will provide an overview of the contents of a web page even when it is too large to be displayed in its entirety. To make maximum use of the limited resources available on a typical hand-held terminal, much of the most demanding work is done by a proxy server, allowing the terminal to concentrate on the task of providing responsive user interaction. The system makes use of some interaction concepts reminiscent of those defined in the Wireless Application Protocol (WAP), making it possible to utilize the techniques described here for WAP-compliant devices and services that may become available in the near future
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Multimedia delivery in the future internet
The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizens’ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications “on the move”, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
Modélisation et distribution adaptatives de grandes scènes naturelles
Cette thèse traite de la modélisation et la diffusion de grandes scènes 3D naturelles. Nous visons à fournir des techniques pour permettre à des utilisateurs de naviguer à distance dans une scène 3D naturelle, tout en assurant la cohérence botanique et l'interactivité. Tout d'abord, nous fournissons une technique de compression multi-résolution, fondée sur la normalisation, l'instanciation, la décorrélation, et sur le codage entropique des informations géometriques pour des modèles de plantes. Ensuite, nous étudions la transmission efficace de ces objets 3D. L'algorithme de paquétisation proposé fonctionne pour la plupart des représentations multi-résolution d'objet 3D. Nous validons les techniques de paquétisation par des expériences sur un WAN (Wide Area Network), avec et sans contrôle de congestion (Datagram Congestion Control Protocol). Enfin, nous abordons les questions du streaming au niveau de la scène. Nous optimisons le traitement des requêtes du côté serveur en fournissant une structure de données adaptée et nous préparons le terrain pour nos travaux futurs sur l'évolutivité et le déploiement de systèmes distribués de streaming 3D. ABSTRACT : This thesis deals with the modeling and the interactive streaming of large natural 3D scenes. We aim at providing techniques to allow the remote walkthrough of users in a natural 3D scene ensuring botanical coherency and interactivity.First, we provide a compact and progressive representation for botanically realistic plant models. The topological structure and the geometry of the plants are represented by generalized cylinders. We provide a multi-resolution compression scheme, based on standardization and instantiation, on difference-based decorrelation, and on entropy coding. Then, we study efficient transmission of these 3D objects. The proposed packetization scheme works for any multi-resolution 3D representation. We validate our packetization schemes with extensive experiments over a WAN (Wide Area Network), with and without congestion control (Datagram Congestion Control Protocol). Finally, we address issues on streaming at the scene-level. We optimize the viewpoint culling requests on server-side by providing an adapted datastructure and we prepare the ground for our further work on scalability and deployment of distributed 3D streaming systems
Adaptive Modeling and Distribution of Large Natural Scenes
This thesis deals with the modeling and the interactive streaming of large natural 3D scenes. We aim at providing techniques to allow the remote walkthrough of users in a natural 3D scene ensuring botanical coherency and interactivity.First, we provide a compact and progressive representation for botanically realistic plant models. The topological structure and the geometry of the plants are represented by generalized cylinders. We provide a multi-resolution compression scheme, based on standardization and instantiation, on difference-based decorrelation, and on entropy coding. Then, we study efficient transmission of these 3D objects. The proposed packetization scheme works for any multi-resolution 3D representation. We validate our packetization schemes with extensive experiments over a WAN (Wide Area Network), with and without congestion control (Datagram Congestion Control Protocol). Finally, we address issues on streaming at the scene-level. We optimize the viewpoint culling requests on server-side by providing an adapted datastructure and we prepare the ground for our further work on scalability and deployment of distributed 3D streaming systems
Audio processing on constrained devices
This thesis discusses the future of smart business applications on mobile phones
and the integration of voice interface across several business applications. It proposes
a framework that provides speech processing support for business applications
on mobile phones. The framework uses Gaussian Mixture Models (GMM)
for low-enrollment speaker recognition and limited vocabulary speech recognition.
Algorithms are presented for pre-processing of audio signals into different categories
and for start and end point detection. A method is proposed for speech processing
that uses Mel Frequency Cepstral Coeffcients (MFCC) as primary feature for extraction.
In addition, optimization schemes are developed to improve performance,
and overcome constraints of a mobile phone. Experimental results are presented
for some prototype applications that evaluate the performance of computationally
expensive algorithms on constrained hardware. The thesis concludes by discussing
the scope for improvement for the work done in this thesis and future directions in
which this work could possibly be extended
An energy efficient http adaptive streaming protocol design for mobile hand-held devices
Internet traffic generated from mobile devices has experienced a huge growth in the last few years. With the increasing popularity of streaming applications in mobile devices, video traffic generated from mobile devices is also increasing. One of the big challenges of streaming applications on mobile devices is the energy intensive behaviour of such applications. Energy management has always been a critical issue for mobile devices. A wireless network interface consumes a significant portion of the total system energy while active. During video streaming, the network interface is kept awake for a long period of time. This causes a large energy drain. There are several research works focused on reducing energy consumption during video streaming on mobile devices.
HTTP adaptive streaming is gaining popularity as a method of video delivery because of its significant advantages in terms of both user-perceived quality and resource utilization. By using rate adaptation via changes in the requested video version, it adapts to varying network available capacity. There are several research work that aim to increase the performance of rate adaptation. None of the previous works have focused on reducing energy consumption during HTTP adaptive streaming.
In this thesis, an energy efficient HTTP adaptive streaming protocol is designed. The new protocol uses an efficient buffer management approach and a three step bitrate selection mechanism. The proposed protocol is implemented by modifying the Adobe OSMF player version 1.6. Performance evaluation of the new protocol is carried out by running a number of experiments in both a lab environment and three real world environments. The experimental results show that the proposed protocol is able to achieve high amounts of sleep time (by more than an estimated 70% for WiFi and more than 35% for 3G/EDGE) and reduce energy consumption during data transfer. It can also reduce data wastage by 80% in case of playback interruption in the video playback
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Distributed multimedia quality: The user perspective
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Distributed multimedia supports a symbiotic infotainment duality, i.e. the ability to transfer information to the user, yet also provide the user with a level of satisfaction. As multimedia is ultimately produced for the education and / or enjoyment of viewers, the user’s-perspective concerning the presentation quality is surely of equal importance as objective Quality of Service (QoS) technical parameters, to defining distributed multimedia quality. In order to extensively measure the user-perspective of multimedia video quality, we introduce an extended model of distributed multimedia quality that segregates quality into three discrete levels: the network-level, the media-level and content-level, using two distinct quality perspectives: the user-perspective and the technical-perspective.
Since experimental questionnaires do not provide continuous monitoring of user attention, eye tracking was used in our study in order to provide a better understanding of the role that the human element plays in the reception, analysis and synthesis of multimedia data. Results showed that video content adaptation, results in disparity in user video eye-paths when: i) no single / obvious point of focus exists; or ii) when the point of attention changes dramatically.
Accordingly, appropriate technical- and user-perspective parameter adaptation is implemented, for all quality abstractions of our model, i.e. network-level (via simulated delay and jitter), media-level (via a technical- and user-perspective manipulated region-of-interest attentive display) and content-level (via display-type and video clip-type). Our work has shown that user perception of distributed multimedia quality cannot be achieved by means of purely technical-perspective QoS parameter adaptation
A mobile tour guide app for sustainable tourism
Portugal has had a flourishing tourism sector for the past few years. In fact, Portugal’s tourism
boom has made the industry one of the biggest contributors to the national economy and the
largest employer. In the year 2019, Portugal had a total of 27 million tourists, surpassing once
again the record established in the previous year. However, tourism also brings a series of
unintended negative side effects, such as overcrowding. The Santa Maria Maior historic district
in Lisbon is being particularly affected by this problem.
The work undertaken in this dissertation is part of the Sustainable Tourism Crowding project,
that aims to mitigate the overcrowding phenomenon in this district, by fostering a balanced
distribution of visitors while promoting the visitation of sustainable points of interest. This
dissertation focuses on developing a mobile app prototype targeted at tourists, through which
these sustainable walking tour recommendations can be delivered.
To validate the functional requirements of the prototype, more specifically the trip creation
process, a series of unit tests, integration tests, and manual tests were developed. To evaluate
the usability of the prototype, a user-centered approach was adopted during the design stage,
in which two usability techniques were conducted with members of ISCTE’s research center
ISTAR and partners from the Junta de Freguesia de Santa Maria Maior, that guided and validated
the decisions made.
The achieved prototype contains mechanisms for measuring tourists’ adherence to the
recommended tours using the Dynamic Time Warping algorithm, which raises new research
opportunities on tourists’ behaviour.O desenvolvimento próspero do setor turístico em Portugal nos últimos anos fez da indústria
um dos maiores contribuintes para a economia nacional e o maior empregador do país. No ano
de 2019, Portugal recebeu um total de 27 milhões de turistas, ultrapassando uma vez mais uma
vez o recorde estabelecido no ano anterior. No entanto, o turismo traz também uma série de
efeitos secundários negativos não intencionais, tais como overcrowding. A freguesia histórica de
Santa Maria Maior em Lisboa está a ser particularmente afetada por este problema.
O trabalho desenvolvido nesta dissertação faz parte do projeto de pesquisa Sustainable
Tourism Crowding, que visa mitigar o fenómeno de overcrowding nesta freguesia, promovendo
uma distribuição equilibrada dos visitantes e incentivando a visita de pontos de interesse
sustentáveis. Esta dissertação foca-se no desenvolvimento de uma aplicação móvel protótipo
destinada a turistas, através do qual recebem recomendações de visitas sustentáveis.
Para validar os requisitos funcionais do protótipo, mais especificamente o processo de
criação de visitas, foram desenvolvidos testes unitários, testes de integração, e testes manuais.
Para avaliar a usabilidade do protótipo, foi adotada uma abordagem centrada no utilizador
durante a fase de conceção, em que foram utilizadas duas técnicas de usabilidade em parceria
com o ISTAR (centro de investigação do ISCTE) e com a Junta de Freguesia de Santa Maria
Maior, cujos resultados guiaram e validaram as decisões tomadas.
O protótipo desenvolvido contém mecanismos para medir a aderência dos turistas às recomendações
sugeridas através do algoritmo Dynamic Time Warping, proporcionando novas
oportunidades de pesquisa nesta área
Development and evaluation of an intelligent handheld insulin dose advisor for patients with Type-1 diabetes
Diabetes mellitus is an increasingly common, chronic, incurable disease requiring careful monitoring
and treatment so as to minimise the risk of serious long-term complications. It has been suggested
that computers used by healthcare professionals and/or patients themselves may playa useful role in
the diabetes care process.
Seven key systems (AIDA, ADICOL, DIABETES, DIAS, IIumaLink, T-IDDM, POIRO) in the area
of diabetes decision support, and their underlying techniques and approaches are summarised and
compared. The development of the Patient-Oriented Insulin Regimen Optimiser (POIRO) for insulindependent (Type-I) diabetes, and its hybrid statistical and rule-based expert system is then taken
forward.
The re-implementation and updating of the system for the Palm OS family of modern Personal Digital
Assistants (PDAs) is described. The evaluation of this new version in a seven week, randomised, open,
cross-over clinical pilot study involving eight patients on short-acting plus long-acting insulin basalbolus
regimens showed it to be easy-to-operate, reliable, not time consuming and well liked by patients.
Following this, the characteristics and use of all currently available insulin formulations, and the corresponding insulin regimens are summarised. Algorithms to provide dose advice and decision support for patients taking the new rapid-acting, intermediate-acting and premixed insulin formulations are then developed. The user interface is improved and extended, amongst others through the development and use of a model describing individual user's meal time habits. Implementation-related issues encountered are discussed, and further work and future directions are identified and outlined.
Motivated by the complex and safety-critical nature of systems such as POIRO, we also report on the
use of the B abstract machine notation for the formal specification of the original POIRO system, and
focusing on projects and published case studies. review the use of formal methods in the development
of medical computer systems
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