Multinational Firms and the Factor Intensity of Trade

In studying the impact of direct investment on the amount, direction, and composition of international trade we have found that the multinational firm fits uncomfortably into the usual theory of trade and capital movements. We attempt here to introduce the fact of the existence of multinational firms into the explanation of trade flows and particularly into the long-running debate over the relations among factor abundance, factor prices and trade.

Fermionic WIMPs and Vacuum Stability in the Scotogenic Model

We demonstrate that the condition of vacuum stability severely restricts scenarios with fermionic WIMP dark matter in the scotogenic model. The sizable Yukawa couplings that are required to satisfy the dark matter constraint via thermal freeze-out in these scenarios tend to destabilise the vacuum at scales below that of the heaviest singlet fermion, rendering the model inconsistent from a theoretical point of view. By means of a scan over the parameter space, we study the impact of these renormalisation group effects on the viable regions of this model. Our analysis shows that a fraction of more than 90% of the points compatible with all known experimental constraints - including neutrino masses, the dark matter density, and lepton flavour violation - is actually inconsistent.Comment: 8 pages, 6 figures; content matches published versio

Futur du nucléaire - Nucléaire du futur

Ecole de Physique Les Houches SFP- SFEN-PACE-CEA-IN2P3 Région Rhône-AlpesL'énergie nucléaire peut jouer un rôle important dans un futur proche pour la production massive d'énergie au niveau mondial. Pour cela, elle devra satisfaire un certain nombre de critères généraux qui ont été définis par les organismes internationaux (IAEA, le Forum International Génération IV), et qui sont : une sûreté accrue, la durabilité par l'utilisation des noyaux fertiles, une bonne gestion des déchets, un champ élargi d'utilisations, une rentabilité économique acceptable et la résistance à la prolifération. Plusieurs concepts sont à l'étude voire en développement pour essayer de répondre à ces critères au sein de collaborations internationales plus ou moins larges. Après une présentation du contexte énergétique et de son futur au niveau mondial, ce papier exposera les arguments en faveur d'un futur du nucléaire en détaillant les avantages de cette forme de production d'énergie, avant une présentation des principaux systèmes en cours d'étude pour le nucléaire du futur

Reliability analysis of dynamic systems by translating temporal fault trees into Bayesian networks

Classical combinatorial fault trees can be used to assess combinations of failures but are unable to capture sequences of faults, which are important in complex dynamic systems. A number of proposed techniques extend fault tree analysis for dynamic systems. One of such technique, Pandora, introduces temporal gates to capture the sequencing of events and allows qualitative analysis of temporal fault trees. Pandora can be easily integrated in model-based design and analysis techniques. It is, therefore, useful to explore the possible avenues for quantitative analysis of Pandora temporal fault trees, and we identify Bayesian Networks as a possible framework for such analysis. We describe how Pandora fault trees can be translated to Bayesian Networks for dynamic dependability analysis and demonstrate the process on a simplified fuel system model. The conversion facilitates predictive reliability analysis of Pandora fault trees, but also opens the way for post-hoc diagnostic analysis of failures