67 research outputs found
Rigorous System Design: The BIP Approach
Rigorous system design requires the use of a single powerful component framework allowing the representation of the designed system at different levels of detail, from application software to its implementation. This is essential for ensuring the overall coherency and correctness. The paper introduces a rigorous design flow based on the BIP (Behavior, Interaction, Priority) component framework. This design flow relies on several, tool-supported, source-to-source transformations allowing to progressively and correctly transform high level application software towards efficient implementations for specific platforms
A model-based approach for multiple QoS in scheduling: from models to implementation
Meeting multiple Quality of Service (QoS) requirements is an important factor in the success of complex software systems. This paper presents an automated, model-based scheduler synthesis approach for scheduling application software tasks to meet multiple QoS requirements. As a first step, it shows how designers can meet deadlock-freedom and timeliness requirements, in a manner that (i) does not over-provision resources, (ii) does not require architectural changes to the system, and that (iii) leaves enough degrees of freedom to pursue further properties. A major benefit of our synthesis methodology is that it increases traceability, by linking each scheduling constraint with a specific pair of QoS property and underlying platform execution model, so as to facilitate the validation of the scheduling constraints and the understanding of the overall system behaviour, required to meet further QoS properties.
The paper shows how the methodology is applied in practice and also presents a prototype implementation infrastructure for executing an application on top of common operating systems, without requiring modifications of the latter
The prospectivity of a potential shale gas play: An example from the southern Pennine Basin (central England, UK)
During the Serpukhovian (late Mississippian) Stage, the Pennine Basin, now underlying much of northern England, consisted of a series of interlinked sub-basins that developed in response to the crustal extension north of the Hercynic orogenic zone. For the current study, mudstone samples of the Morridge Formation from two sub-basins located in the south-eastern part of the Pennine Basin were collected from the Carsington Dam Reconstruction C3 Borehole (Widmerpool Gulf sub-basin) and the Karenight 1 Borehole (Edale Gulf sub-basin). Detailed palynological analyses indicate that aside from the dominant (often 90% or more) heterogeneous amorphous organic matter (AOM), variable abundances of homogeneous AOM and phytoclasts are present. To complement the palynological dataset, a suite of geochemical and mineralogical techniques were applied to evaluate the prospectivity of these potentially important source rocks. Changes in the carbon isotope composition of the bulk organic fraction (δ13COM) suggest that the lower part (Biozone E2a) of Carsington DR C3 is markedly more influenced by terrigenous kerogen than the upper part of the core (Biozones E2a3–E2b1). The Karenight 1 core yielded more marine kerogen in the lower part (Marine Bands E1–E2b) than the upper part (Marine Band E2b). Present day Rock-Eval™ Total Organic Carbon (TOC) surpasses 2% in most samples from both cores, a proportion suggested by Jarvie (2012) that defines prospective shale gas reservoirs. However, when the pyrolysable component that reflects the generative kerogen fraction is considered, very few samples reach this threshold. The kerogen typing permits for the first time the calculation of an original hydrogen index (HIo) and original total organic carbon (TOCo) for Carboniferous mudstones of the Pennine Basin. The most prospective part of Carsington DR C3 (marine bands E2b1–E2a3) has an average TOCo of 3.2% and an average HIo of 465 mg/g TOCo. The most prospective part of Karenight 1 (242.80–251.89 m) is characterized by an average TOCo of 9.3% and an average HIo of 504 mg/g TOCo. Lastly, X-ray diffraction (XRD) analysis confirms that the siliceous to argillaceous mudstones contain a highly variable carbonate content. The palynological, geochemical and mineralogical proxies combined indicate that marine sediments were continuously being deposited throughout the sampled intervals and were punctuated by episodic turbiditic events. The terrestrial material, originating from the Wales-Brabant High to the south of the Pennine Basin, was principally deposited in the Widmerpool Gulf, with much less terrigenous organic matter reaching the Edale Gulf. As a consequence, the prospective intervals are relatively thin, decimetre-to meter-scale, and further high resolution characterization of these intervals is required to understand variability in prospectivitiy over these limited intervals
La géochimie organique des sédiments marins profonds mission orgon1, 1974 (mer de Norvège). Première Partie
On présente quelques généralités sur la constitution et les buts du groupe ORLON, groupe d'étude de la géochimie organique des sédiments marins profonds qui comprend, outre l'IFP, les compagnies CFP, Elf-RE et SNPA et un certain nombre de laboratoires universitaires et du CNRS (Paris VI, Bordeaux, Strasbourg, Nancy, Perpignan, Aix-Marseille). Un premier compte rendu de la mission ORLON 1974 en mer de Norvège insiste sur les quatre premières mondiales réalisées à son occasion - utilisation du carottier par gravité Reineck long (12 m) par mer profonde (jusqu'à 2000 m); - dosage du carbone organique à bord par appareil automatique LECO ; - lyophilisation à bord de grandes quantités de sédiments ; - cultures et numération bactériennes à bord sur prélèvements le long d'une carotte longue (jusqu'à 13,5 m)
A Virtual Organisation for e-Learning
We present in this paper the results of an European funded project Diogene, finished in October
2004, whose aim has been the design and the development of a distributed e-learning system able
to perform several automatic actions such as course customization and information retrieval on the
Semantic Web. The Diogene architecture is based on a network of specialized Organizations each
of which has been realized as an independent Web Service
- …