Third Party Access pricing to the network, secondary capacity market and economic optimum : the case of natural gas

The gas deregulation process implies crucial choices concerning access to transportation networks. These choices deal with the nature, the structure and the level of access fees. This paper proposes an evaluation of different systems implemented both in Europe and North America, in relation to normative pricing references. The rules according to which shippers can buy or sell capacity represent another kind of choice that Regulators have to make. This paper proposes a simple model which demonstrates that secondary market prices should not be subject to a cap and emphasizes the need of a 'use-it-or-lose-it' rule on this market.DEREGLEMENTATION; INVESTISSEMENT; OPTION REELLE; FINANCEMENT OPTIMAL; PRIX DE REVIENT; ELECTRICITE

The time-inconsistency of alternative energy policy

Time-inconsistency can arise when a government attempts to convince private sector to use a particular alternative energy (gas, green electricity...) rather than petroleum products. By introducing taxes and feed-in prices, a government would encourage firms and households to switch to an alternative energy rather than use petroleum products. However, even if a government is in favor of increasing alternative energy consumption, it can benefit from considerable financial resources resulting from petroleum product consumption. As a result of these conflicting issues, the private sector may not find the alternative energy policy credible, which prevents the government to implement a socially efficient policy.Time-inconsistency Energy policy Tax expenditures

La dérégulation de l'industrie électrique en Europe et aux Etats-Unis : un processus de décomposition-recomposition

The deregulation of electric industry in Europe and in the U.S.A. assumes various aspects according to each country. Several institutionnal, economic and political reasons explain this evolution. Electric firms take this opportunity to merge and to implement offensive strategies on global markets. A lot of questions remains unsolved, in particular the problem of TPA pricing and the problem of planning of network infrastructures over the long run.ELECTRIC INDUSTRY ; DEREGULATION ; ENERGY PRICING ; PUBLIC UTILITIES

Towards a Rule-level Verification Framework for Property-Preserving Graph Transformations

International audienceWe report in this paper a method for proving that a graph transformation is property-preserving. Our approach uses a relational representation for graph grammar and a logical representation for graph properties with first-order logic formulas. The presented work consists in identifying the general conditions for a graph grammar to preserve graph properties, in particular structural properties. We aim to implement all the relevant notions of graph grammar in the Isabelle/HOL proof assistant in order to allow a (semi) automatic verification of graph transformation with a reasonable complexity. Given an input graph and a set of graph transformation rules, we can use mathematical induction strategies to verify statically if the transformation preserves a particular property of the initial graph. The main highlight of our approach is that such a verification is done without calculating the resulting graph and thus without using a transformation engine

Les enjeux du transport pour le gaz et l'électricité : la fixation des charges d'accès

ATR ; GAZ NATUREL ; ELECTRICITE

A Modeling and Formal Approach for the Precise Specification of Security Patterns

International audienceNon-functional requirements such as Security and Dependability (S &D) become more important as well as more difficult to achieve. In fact, the integration of security features requires the availability of both application domain specific knowledge and security expertise at the same time. Hence, capturing and providing this expertise by the way of security patterns can support the integration of S&D features by design to foster reuse during the process of software system development.The solution envisaged here is based on combining metamodeling techniques and formal methods to represent security pattern at two levels of abstraction fostering reuse during the process of pattern development and during the process of pattern-based development. The contribution of this work is twofold: (1) An improvement of our previous pattern modeling language for representing security pattern in the form of a subsystem providing appropriate interfaces and targeting security properties, (2) Formal specification and validation of pattern properties, using the interactive Isabelle/HOL proof assistant. The resulting validation artifacts may mainly complete the definitions, and provide semantics for the interfaces and the properties in the context of S&D. As a result, validated patterns will be used as bricks to build applications through a Model-Driven engineering approach

Deep neural networks for inverse problems in mesoscopic physics: Characterization of the disorder configuration from quantum transport properties

We present a machine learning approach that allows to characterize the disorder potential of a two-dimensional electronic system from its quantum transport properties. Numerically simulated transport data for a large number of disorder configurations is used for the training of artificial neural networks. We show that the trained networks are able to recognize details of the disorder potential of an unknown sample from its transport properties, and that they can even reconstruct the complete potential landscape seen by the electrons.Comment: 12 pages, 11 figure