Optimisation fiscale | EPFL Graph Search

L'optimisation fiscale ou évitement fiscal (en anglais tax planning ou tax avoidance) est l'utilisation des asymétries du droit fiscal de différents pays ou régimes (régimes dérogatoires, utilisation de niches fiscales…) afin de réduire le montant de l'imposition tout en respectant les obligations fiscales de chaque pays. L'optimisation fiscale concerne autant l'imposition des personnes que celle des sociétés. Elle comprend les notions d'évasion fiscale et d'expatriation fiscale et se distingue de la fraude fiscale (en anglais tax evasion) ou encore de la résistance fiscale par son aspect légal. Aspects techniques Les principales techniques d'optimisation qu'utilisent les entreprises sont :

les redevances ;
les prix de transfert (prix de cession de biens ou de services échangés au sein d'un même groupe) ;
les charges financières (optimisation fiscale par sous-capitalisation) ;
l'implantation dans un pays offrant un régime avantageux (expatriation fiscale ou évasi

CO2-mitigation options for the offshore oil and gas sector

François Maréchal, Tuong-Van Nguyen, Laurence Tock

The offshore extraction of oil and gas is an energy-intensive process leading to the production of CO2 and methane, discharged into the atmosphere, and of chemicals, rejected into the sea. The taxation of these emissions, in Norway, has encouraged the development of more energy-efficient and environmental-friendly solutions, of which three are assessed in this paper:. (i) the implementation of waste heat recovery, (ii) the installation of a CO2-capture unit and (iii) the platform electrification. A North Sea platform is taken as case study, and these three options are modelled, analysed and compared, using thermodynamic, economic and environmental indicators. The results indicate the benefits of all these options, as the total CO2-emissions can be reduced by more than 15% in all cases, while the avoidance costs vary widely and are highly sensitive to the natural gas price and CO2-tax. (C) 2015 Elsevier Ltd. All rights reserved.

2016

Dense Disparity Estimation from Omnidirectional Images

Zafer Arican, Pascal Frossard

This paper addresses the problem of dense estimation of disparities between omnidirectional images, in a spherical framework. Omnidirectional imaging certainly represents important advantages for the representation and processing of the plenoptic function in 3D scenes for applications in localization, or depth estimation for example. In this context, we propose to perform disparity estimation directly in a spherical framework, in order to avoid discrepancies due to inexact projections of omnidirectional images onto planes. We ﬁrst perform rectiﬁcation of the omnidirectional images in the spherical domain. Then we develop a global energy minimization algorithm based on the graph-cut algorithm, in order to perform disparity estimation on the sphere. Experimental results show that the proposed algorithm outperforms typical methods as the ones based on block matching, for both a simple synthetic scene, and complex natural scenes. The proposed method shows promising performances for dense disparity estimation and can be extended efﬁciently to networks of several camera sensors.

2007

Thermo-chemical H2 production: Thermo-economic modeling and process integration

François Maréchal, Laurence Tock

Within the global challenge of climate change and energy security, hydrogen is considered as a promising decarbonized energy vector to be used in electricity production and transportation. In this paper, the thermo-chemical production of hydrogen by natural gas reforming and by lignocellulosic biomass gasification are analyzed, compared and optimized by developing thermo-economic models. Combining flowsheeting with process integration techniques, thermo-economic analysis and life cycle assessment (LCA), a systematic comparison of different process options with regard to energy, economic and environmental considerations is made. The choice of the technologies is optimized together with the operating conditions using multi-objective optimization. In both natural gas and biomass based H2 pathways, a CO2 removal step is included during the H2 purification which allows for CO2 capture and further sequestration. The potential for greenhouse gas mitigation is assessed and compared with conventional plants without capture based on the CO2 avoidance cost and the overall CO2 equivalent emissions computed from the life cycle chain. The system’s performance is improved by introducing process integration valorizing the waste heat by the combined production of heat and power. The H2 application purpose and the corresponding required purity are key factors defining the process performance. The trade-offs between competing thermoenvironomic (i.e. energy, economic and environmental) objectives are finally assessed using a multi-objective optimization. For natural gas based H2 production overall energy efficiencies up to 80% and production cost of 22-110 USD/MWH2 are computed compared to around 60% efficiency and 75-263 USD/MWhH2 for biomass based processes having the advantage of using renewable resources. The CO2eq emissions are reduced by more than 6.4kgCO2eq/kgH2 for NG and 20kgCO2eq/kgH2 for BM processes compared to the cases without CO2 capture. The competitiveness on the energy market depends strongly on the resource price and on the imposed CO2 taxes. Our study shows that the thermo-chemical hydrogen production has to be analyzed as a polygeneration unit producing not only hydrogen but also captured CO2 and electricity.

2011

Thermo-chemical H2 production: Thermo-economic modeling and process integration

François Maréchal, Laurence Tock

2011