Un instrument de court terme pour stimuler la concurrence le gas release

This paper develops a simple model for examining the gas-release programs as the unique tool to improve the performance of imperfectly competitive natural gas markets. We study the «artificial» duopoly effect created by first the incumbent and then by a regulator who introduces a gas-release program under both a partial and a global budget-balance constraint imposed on the incumbent. Calibration and simulation techniques are used to compare these scenarios under different assumptions on the way regulation is conducted. © Presses de Sciences Po

Gateway: New high performance computing facility for EFDA task force on integrated Tokamak modelling

The EFDA task force on Integrated Tokamak Modelling (ITM-TF) is providing the EU fusion community with a complete and flexible suite of reliable software tools and codes able to simulate the next ITER and DEMO plasma discharges. EFDA has launched the Gateway project as the first computing facility to be jointly used by EU fusion associations. The Gateway has been designed to allow the ITM-TF members to work together on a common platform and share their codes, developments tools and technologies as well as to make able the inter-operation with tera-scale supercomputer facilities. Technically the Gateway is a rather small high computing facility in operation since 2008, with 1 Teraflops of theoretical peak and 100 Terabytes shared storage area for experimental and simulation data. This paper describes the information technologies involved in the Gateway facility, particularly as regards the low latency interconnect network for multi-core platform as well as fast I/O solutions implemented with storage over Infiniband and high performance parallel file systems. The solutions adopted on the Gateway facility had undergone to specific benchmarks showing excellent performances in typical fusion data handling issues. Finally the interoperability between Gateway and ENEA CRESCO supercomputer will be described showing the access solutions that allow the exploitation of tera-scale supercomputer facilities

Un instrument de court terme pour stimuler la concurrence le gas release

This paper develops a simple model for examining the gas-release programs as the unique tool to improve the performance of imperfectly competitive natural gas markets. We study the «artificial» duopoly effect created by first the incumbent and then by a regulator who introduces a gas-release program under both a partial and a global budget-balance constraint imposed on the incumbent. Calibration and simulation techniques are used to compare these scenarios under different assumptions on the way regulation is conducted. © Presses de Sciences Po

Simulation and high performance computing-Building a predictive capability for fusion

The Integrated Tokamak Modelling Task Force (ITM-TF) is developing an infrastructure where the validation needs, as being formulated in terms of multi-device data access and detailed physics comparisons aiming for inclusion of synthetic diagnostics in the simulation chain, are key components. As the activity and the modelling tools are aimed for general use, although focused on ITER plasmas, a device independent approach to data transport and a standardized approach to data management (data structures, naming, and access) is being developed in order to allow cross-validation between different fusion devices using a single toolset. Extensive work has already gone into, and is continuing to go into, the development of standardized descriptions of the data (Consistent Physical Objects). The longer term aim is a complete simulation platform which is expected to last and be extended in different ways for the coming 30 years. The technical underpinning is therefore of vital importance. In particular the platform needs to be extensible and open-ended to be able to take full advantage of not only today\u27s most advanced technologies but also be able to marshal future developments. As a full level comprehensive prediction of ITER physics rapidly becomes expensive in terms of computing resources, the simulation framework needs to be able to use both grid and HPC computing facilities. Hence data access and code coupling technologies are required to be available for a heterogeneous, possibly distributed, environment. The developments in this area are pursued in a separate project-EUFORIA (EU Fusion for ITER Applications) which is providing about 15 professional person year (ppy) per annum from 14 different institutes. The range and size of the activity is not only technically challenging but is providing some unique management challenges in that a large and geographically distributed team (a truly pan-European set of researchers) need to be coordinated on a fairly detailed project level. The 2009 Work programme of ITM-TF organizes 240 individuals from 24 different associations providing about 60 ppy in total. Remote participation and collaborative tools and facilities as the ENEA sponsored Gateway have proven indis-pensible to meet this challenge. The current status of ITM-TF and EUFORIA is presented and discussed