A Framework for Quality-Driven Delivery in Distributed Multimedia Systems

In this paper, we propose a framework for Quality-Driven Delivery (QDD) in distributed multimedia environments. Quality-driven delivery refers to the capacity of a system to deliver documents, or more generally objects, while considering the users expectations in terms of non-functional requirements. For this QDD framework, we propose a model-driven approach where we focus on QoS information modeling and transformation. QoS information models and meta-models are used during different QoS activities for mapping requirements to system constraints, for exchanging QoS information, for checking compatibility between QoS information and more generally for making QoS decisions. We also investigate which model transformation operators have to be implemented in order to support some QoS activities such as QoS mapping

Model Management for Quality of Service Support

Quality of Service (QoS) management strategies have been first introduced in distributed multimedia systems to decide whether and controlling how multimedia streams can be delivered to the user within the given delay, cost or quality constraints. With the recent advances in the development of large-scale distributed applications where different services are provided to a large number of users, QoS management becomes and end-to-end functionality requiring the cooperation of all the system components. That leads to consider system components interoperability, management information integration and distributed execution of QoS activities. In this paper we examine modelling and meta-modelling issues for QoS management. More specifically we propose a meta-model for QoS management and we illustrate how such a meta-model is used for mapping QoS requirements to system constraints

Predicting the impact of land use on the major element and nutrient fluxes in coastal Mediterranean rivers: The case of the Teˆt River (Southern France)

This study presents a detailed discrimination between the natural and anthropogenic sources of dissolved major elements in the Teˆt River, a typical small coastal river in the south of France. The main objectives were to quantify the materials that were released by human activities in the basin, and to determine the specific element inputs for the major land use forms. The dissolved material fluxes were estimated by weekly monitoring over a hydrological year (2000–2001) along the major water gauging stations, and the flux relationships were examined in the context of anthropogenic and natural basin characteristics as determined by a Geographical Information System (GIS). Intensive agricultural land use in the form of fruit tree cultures and vineyards has a strong control on the dissolved element fluxes in the river. Area specific element releases for these cultures are greatest for SO4, with an estimated average of about 430 ± 18 keq km2 a1. This is P11 times the natural SO4 release by rock weathering. Also for K, NO3, PO4 and Mg, the specific releases were P6 times the natural weathering rates (respectively about 44, 60, 4 and 265 keq km2 a1). Waste-waters are the other major source of anthropogenic elements in the river. They have an important role for the fluxes of inorganic P and N, but they are also a considerable source of Cl and Na to the river. For example, the average annual release of Cl is around 150 moles/inhabitant in the rural basin parts. Further downstream, however, where population density strongly increases, industrial effluents can enhance this value (>300 moles/inhabitant). The waste-waters contribute more than 70% of the dissolved inorganic N export to the sea, although their contribution to the average DOC export is almost negligible (3%)

An adaptation framework for new media artworks

In this paper, we are interested in adaptation mechanisms for the design, creation and experimentation of adaptive and interactive new media artworks. Through a concrete case study, we propose an adaptation framework that combines semantic and physical adaptation and that can be specialized to the specific needs of various new media artists. This adaptation framework is supported by an adaptation engine, the kernel of the software architecture we are currently building. We have validated our adaptation framework through the implementation of a prototype of the adaptation engine. This prototype integrates the management of various types of metadata and allows a representation of adaptation scenarios as policies of the form event-condition-action. \ud We present how we used our adaptation engine to reconstruct and experiment the adaptation model of The Man of the Crowd, an existing adaptive new media installation, where the artist introduces a semantic adaptation of the video content displayed on four screens, according to the relative position of the viewer in the artistic installation

Model Operations for Quality-Driven Multimedia Delivery

With the recent advances in distributed systems and wireless technology, users can access any information, from anywhere with any device. Multimedia delivery services are currently under development to operate in such environments. In this context, it appears essential to offer and support different levels of service according to users requirements and expectations and to work towards quality-driven delivery (QDD). Implementing QDD mechanisms leads us to consider different issues such as system components interoperability, quality information management, distributed execution of QDD activities and multi-criteria optimization. In this paper, we focus on quality information management to support QDD. We propose a model management approach to the problem and we introduce metamodel and model operations for that purpose. We use conceptual graphs formalism to develop our QDD metamodel and we show how the conceptual graph derivation mechanism can be applied to implement some fundamental model operations

Process modeling for new media artworks

Practices in new media art pose very interesting challenges to the multimedia research community in terms of software tools development, usage of media technologies or documentation and conservation of new meda artworks. In this paper, we present the different stages in the life cycle of new media artworks and we illustrate the use of the canonical processes of media production in this context. This work is a first step towards a process modeling framework for the description and documentation of new media artworks

Design and production of new media artworks

New media artists today take advantage of, and are influenced by, the many possibilities offered by new digital technologies. They are very demanding users and a detailed examination of their practices and approaches will provide a better understanding of the usage of multimedia technologies. In this paper, we are interested in the design and creation of new media artworks. Through a concrete example, we present the different stages in the life cycle of an adaptive new media artwork and we identify the corresponding canonical processes

A QoS mapping rule builder

Although many QoS management architectures have been recently introduced with a lot of advanced features, they have never been widely used in the existing applications due to the lack of interoperation between providers and users, or between network operators. One of the main issues is the heterogeneity of QoS information coming from different sources: clients, communication networks, servers, data .etc. In the context of Quality-Driven Delivery (QDD) referring to the ability of a system to deliver data objects while considering the end-users expectations, all components of a distributed multimedia system have to contribute to satisfy users requirements. The mapping activity is therefore essential for dealing with the variety of QoS information of these components. In this paper, we propose an approach aimed at creating QoS mapping rules using statistical data analysis and data mining techniques combined with monitoring tools. The automatic generation of QoS mapping rules allows adapting the QoS management architectures to different environments as well as different classes of users

Pacing during an ultramarathon running event in hilly terrain

PURPOSE: The dynamics of speed selection as a function of distance, or pacing, are used in recreational, competitive, and scientific research situations as an indirect measure of the psycho-physiological status of an individual. The purpose of this study was to determine pacing on level, uphill and downhill sections of participants in a long (>80 km) ultramarathon performed on trails in hilly terrain. METHODS: Fifteen ultramarathon runners competed in a 173 km event (five finished at 103 km) carrying a Global-Positioning System (GPS) device. Using the GPS data, we determined the speed, relative to average total speed, in level (LEV), uphill (UH) and downhill (DH) gradient categories as a function of total distance, as well as the correlation between overall performance and speed variability, speed loss, and total time stopped. RESULTS: There were no significant differences in normality, variances or means in the relative speed in 173-km and 103-km participants. Relative speed decreased in LEV, UH and DH. The main component of speed loss occurred between 5% and 50% of the event distance in LEV, and between 5% and 95% in UH and DH. There were no significant correlations between overall performance and speed loss, the variability of speed, or total time stopped. CONCLUSIONS: Positive pacing was observed at all gradients, with the main component of speed loss occurring earlier (mixed pacing) in LEV compared to UH and DH. A speed reserve (increased speed in the last section) was observed in LEV and UH. The decrease in speed and variability of speed were more important in LEV and DH than in UH. The absence of a significant correlation between overall performance and descriptors of pacing is novel and indicates that pacing in ultramarathons in trails and hilly terrain differs to other types of running events

Interpolatory-based data-driven pulsed fluidic actuator control design and experimental validation

Pulsed fluidic actuators play a central role in the fluid flow experimental control strategy to achieve better performances of aeronautic devices. In this paper, we demonstrate, through an experimental test bench, how the interpolatory-based Loewner Data-Driven Control (L-DDC) framework is an appropriate tool for accurately controlling the outflow velocity of this family of actuators. L-DDC combines the concept of ideal controller with the Loewner framework in a single data-driven rationale, appropriate to experimental users. The contributions of the paper are, first, to emphasise the simplicity and versatility of such a data-driven rationale in a constrained experimental setup, and second, to solve some practical fluid engineers concerns by detailing the complete workflow and key ingredients for successfully implementing a pulsed fluidic actuator controller from the data acquisition to the control implementation and validation stages.Comment: 20 pages, 7 figure