17 research outputs found
Optimisation énergétique de processus de traitement du signal et ses applications au décodage vidéo
Consumer electronics offer today more and more features (video, audio, GPS, Internet) and connectivity means (multi-radio systems with WiFi, Bluetooth, UMTS, HSPA, LTE-advanced ... ). The power demand of these devices is growing for the digital part especially for the processing chip. To support this ever increasing computing demand, processor architectures have evolved with multicore processors, graphics processors (GPU) and ether dedicated hardware accelerators. However, the evolution of battery technology is itself slower. Therefore, the autonomy of embedded systems is now under a great pressure. Among the new functionalities supported by mobile devices, video services take a prominent place. lndeed, recent analyzes show that they will represent 70% of mobile Internet traffic by 2016. Accompanying this growth, new technologies are emerging for new services and applications. Among them HEVC (High Efficiency Video Coding) can double the data compression while maintaining a subjective quality equivalent to its predecessor, the H.264 standard. ln a digital circuit, the total power consumption is made of static power and dynamic power. Most of modern hardware architectures implement means to control the power consumption of the system. Dynamic Voltage and Frequency Scaling (DVFS) mainly reduces the dynamic power of the circuit. This technique aims to adapt the power of the processor (and therefore its consumption) to the actual load needed by the application. To control the static power, Dynamic Power Management (DPM or sleep modes) aims to stop the voltage supplies associated with specific areas of the chip. ln this thesis, we first present a model of the energy consumed by the circuit integrating DPM and DVFS modes. This model is generalized to multi-core integrated circuits and to a rapid prototyping tool. Thus, the optimal operating point of a circuit, i.e. the operating frequency and the number of active cores, is identified. Secondly, the HEVC application is integrated to a multicore architecture coupled with a sophisticated DVFS mechanism. We show that this application can be implemented efficiently on general purpose processors (GPP) while minimizing the power consumption. Finally, and to get further energy gain, we propose a modified HEVC decoder that is capable to tune its energy gains together with a decoding quality trade-off.Aujourd'hui, les appareils électroniques offrent de plus en plus de fonctionnalités (vidéo, audio, GPS, internet) et des connectivités variées (multi-systèmes de radio avec WiFi, Bluetooth, UMTS, HSPA, LTE-advanced ... ). La demande en puissance de ces appareils est donc grandissante pour la partie numérique et notamment le processeur de calcul. Pour répondre à ce besoin sans cesse croissant de nouvelles fonctionnalités et donc de puissance de calcul, les architectures des processeurs ont beaucoup évolué : processeurs multi-coeurs, processeurs graphiques (GPU) et autres accélérateurs matériels dédiés. Cependant, alors que de nouvelles architectures matérielles peinent à répondre aux exigences de performance, l'évolution de la technologie des batteries est quant à elle encore plus lente. En conséquence, l'autonomie des systèmes embarqués est aujourd'hui sous pression. Parmi les nouveaux services supportés par les terminaux mobiles, la vidéo prend une place prépondérante. En effet, des analyses récentes de tendance montrent qu'elle représentera 70 % du trafic internet mobile dès 2016. Accompagnant cette croissance, de nouvelles technologies émergent permettant de nouveaux services et applications. Parmi elles, HEVC (High Efficiency Video Coding) permet de doubler la compression de données tout en garantissant une qualité subjective équivalente à son prédécesseur, la norme H.264. Dans un circuit numérique, la consommation provient de deux éléments: la puissance statique et la puissance dynamique. La plupart des architectures matérielles récentes mettent en oeuvre des procédés permettant de contrôler la puissance du système. Le changement dynamique du couple tension/fréquence appelé Dynamic Voltage and Frequency Scaling (DVFS) agit principalement sur la puissance dynamique du circuit. Cette technique permet d'adapter la puissance du processeur (et donc sa consommation) à la charge réelle nécessaire pour une application. Pour contrôler la puissance statique, le Dynamic Power Management (DPM, ou modes de veille) consistant à arrêter les alimentations associées à des zones spécifiques de la puce. Dans cette thèse, nous présentons d'abord une modélisation de l'énergie consommée par le circuit intégrant les modes DVFS et DPM. Cette modélisation est généralisée au circuit multi-coeurs et intégrée à un outil de prototypage rapide. Ainsi le point de fonctionnement optimal d'un circuit, la fréquence de fonctionnement et le nombre de coeurs actifs, est identifié. Dans un second temps, l'application HEVC est intégrée à une architecture multi-coeurs avec une adaptation dynamique de la fréquence de développement. Nous montrons que cette application peut être implémentée efficacement sur des processeurs généralistes (GPP) tout en minimisant la puissance consommée. Enfin, et pour aller plus loin dans les gains en énergie, nous proposons une modification du décodeur HEVC qui permet à un décodeur de baisser encore plus sa consommation en fonction du budget énergétique disponible localement
P2PCompute - A Peer-to-Peer Computing Model
Peer-to-peer (P2P) networks consist of nodes which have both client and server capabilities and on which communication and data sharing is carried on directly between nodes, rather than being arbitrated by an intermediary node. The P2P architecture was popularized by file-sharing, one of the widely-used applications of the Internet. Many applications that are based on this architecture have been developed. It also provides an efficient platform to harness the computing power of a network of desktop computers. P2P computing power can help solve computationally complex problems that require powerful supercomputers. However, it has not been as widely used as the file-sharing P2P applications. Almost all of the current P2P computing applications are noncommercial endeavors. Users make their computing power available for these endeavors because they believe in the applications\u27 objectives, for example, the SETI project analyzes radio telescope data in the quest for life in other parts of the universe.
This thesis proposes P2PCompute - a viable commercial model in the P2P computing field. It harnesses existing technologies- P2P, Java, the Internet and the UDDI registry, to enable distributed processing of tasks on multiple servers. It is well-suited to the heterogeneous environment on the Internet and has the potential to provide the spark that would lead to the development of more commercial P2P computing applications
Computational method development for drug discovery
Protein-small molecule interactions play a central role in various aspects of the structural and functional organization of the cell and are therefore integral for drug discovery. The most comprehensive structural characterization of small molecule binding sites is provided by X-ray crystallography. However, it is often time-consuming and challenging to perform direct experimental analysis. Therefore, it is necessary to have computational methods that can predict binding site locations on unbound structures with accuracy close to that provided by X-ray crystallography. This thesis details four projects which involve the development of a fragment benchmark set, evaluation of allosteric sites in G Protein-Coupled Receptors (GPCRs), computational modeling of binding pocket dynamics, and the development of an Application Program Interface (API) framework for High-Performance Computing (HPC) centers.
The first project provides a benchmark set for testing hot spot identification methods, emphasizing application to fragment-based drug discovery. Using the solvent mapping server, FTMap, which finds small molecule binding hot spots on proteins, we compared our benchmark set to an existing benchmark set that with a different method of construction. The second project details the effort to identify allosteric binding sites on GPCRs. We demonstrate that FTMap successfully identifies structurally determined allosteric sites in bound crystal structures and unbound structures. The project was further expanded to evaluate the conservation of allosteric sites across different classes, families, and types of GPCRs. The third project provides a structure-based analysis of cryptic site openings. Cryptic sites are pockets formed in ligand-bound proteins but not observed in unbound protein structures. Through analysis of crystal structures supplemented by molecular dynamics (MD) with enhanced sampling techniques, it was shown that cryptic sites can be grouped into three types: 1) “genuine” cryptic sites, which do not form without ligand binding, 2) spontaneously forming cryptic sites, and 3) cryptic sites impacted by mutations or off-site ligand binding. The fourth project presents an API framework for increasing the accessibility of HPC resources
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Dynamic Application Integration Using Peer to Peer Technology
Today's business imperatives are clearer than ever. Businesses are trying to beat competitors by introducing new products to the market, deliver personalised services, increase customer loyalty and evolve at electronic speeds. These imperatives demand a technology infrastructure that is more flexible, more dynamic and more intelligent than ever. Java Web services based on Universal Description, Discovery and Integration (UDDI) are an evolution in e-business applications that will help businesses reach these goals and take Business-to-Business (B2B) to the next level.
In the last couple of years, the concept of a Web Service (WS) has emerged as an important paradigm for general application integration in the internet environment. More particularly, WS is viewed as an important vehicle for the creation of dynamic e business applications and as a means for the Java 2 Enterprise Edition (J2EE) and Microsoft .NET platforms to come together. This will be achieved through WS standards and several companies have been collaborating in such standardisation activities.
This Thesis describes research aiming to allow the dynamic integration of different software applications and information sources, including legacy systems, using the latest state of the art Internet technology called “Peer-to-Peer (P2P)”. The term “dynamic” is used in order to indicate that different software applications, in different geographical locations, that need to be integrated are able to establish a communication link and interchange data without manual intervention or without any intermediate integration server. To achieve this goal, several technologies have been combined, including Java Web Services and the Extensible Stylesheet Language (XML), in order to design, develop and implement an innovative architecture that will satisfy such requirements. Amongst others, the main programming language used is the widely accepted Java language, which acts catalytically in the creation of the system architecture described in this Thesis
Building a health and environment geographical information system :an evaluation, looking at childhood cancer in Northern England
PhD ThesisThe aim of this research was to evaluate a relatively young technology, Geographical
Information Systems (GIS), in a specific applications environment. The application
adopted was that of searching for environmental causes of childhood cancer, in
particular that of Acute Lymphoblastic Leukaemia (ALL), in Northern England. It is
also relevant in terms of the WHO's intention to develop a Health and Environment
GIS, and therefore the research aims to satisfy their recommendations for pilot
studies.
The subject matter of this thesis therefore covers two very high profile topics, which it
is believed will mutually benefit from the research carried out. Firstly, very little is
known about the aetiology of ALL, and thus any new methodology which is
introduced to help analyse sensitive issues of causation is welcomed not only by those
in the medical field but also the public. The application was made possible with the
provision of detailed cancer data for Northern England and a weak but interesting
hypothesis that environmental factors may be an attributable mechanism for
causation. Key questions which are asked include; Where are incidences of ALL
located? Why are they there? Is there a cluster? and What could be the cause?
Secondly a Geographical Information System, in this case the proprietary software
package ARC/INFO, was considered an excellent medium for tackling this spatial
epidemiological problem. Especially with its capability to store large volumes of
diverse data, and its inherent flexibility to deal with spatial information pertaining to
health and environmental factors. More importantly the application itself offered a
means of evaluating the implementation of a GIS. Establishing the advantages and
pitfalls which accompany all stages of 'The GIS Process' and an invaluable
documentation of the experiences acquired as an initiator, developer and implementor
of this new technology.
In addition, this research offers fresh ideas and techniques for improving those areas
of the technology which appear to be lacking in these early phases of its development.
The problems of spatial analysis in GIS and the provision of useful tools such as
'pattern spotters', 'relationship seekers' and 'error handlers' are discussed as alternative
techniques. To ensure an exciting future for GIS technology in application
environments the latter and other key areas of research which should be persued are
highlighted in this thesis
Aeronautical engineering: A continuing bibliography with indexes (supplement 301)
This bibliography lists 1291 reports, articles, and other documents introduced into the NASA scientific and technical information system in Feb. 1994. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
Transport governance and the environment: the changing decision making context of road transport in north east England
The environmental problems originating from transport are considerable, persistent and increasing. In personal travel there is a continuing switch away from public transport towards the private car. Also the proportion of freight moving by road is increasing in volume and distance. These trends reveal that the transport of both people and goods is less sustainable than it was. Altering existing transport behaviour to reduce demand, simultaneously shaping suppressed demand, and achieving both whilst maintaining politically acceptable levels of access and mobility are serious challenges. This thesis explores a part of the complex landscape of transport decision making where theses tensions are enacted, focussing on three key group of organisations within the road transport sector of the north east of England. The thesis assess the salience of ‘the environment’ within the minds of organisational transport decision makers in the North East. Their views on the environment and its importance within their decisions will affect the success of policy initiatives. Examining transport choices within this context reveals the depth of ‘environmental’ understanding present within the operational landscape of transport. It is argued that theoretical and conceptual approaches to the process of transport policy development have matured, whilst the implementation of transport policy resulting from this process remains somewhat patchy with traditional approaches to transport provision remaining dominant. The argument is covered in terms of transport paradigms. Though sustainability policies remain, recent integrated transport initiatives are undermined from the centre by a return to the market paradigm and to ‘predict and provide’. Within this research clear evidence has emerged of reinterpretations of ‘the environment’ taking place, Theses discoveries illustrate the ability of governance and organisational actors to assimilate emerging policy requirements into existing or preferred programmes and transport behaviours, in support of the aims of recent transport policies the ability to identify economic and environmental ‘win-win’ opportunities was found to be important. Decisive leadership was found to deliver effective transport policies
Program and abstracts from the 24th Fungal Genetics Conference
Abstracts of the plenary and poster sessions from the 24th Fungal Genetics Conference, March 20-25, 2007, Pacific Grove, CA