Orientational ordering in crumpled elastic sheets

We report an experimental study of the development of orientational order in a crumpled sheet, with a particular focus on the role played by the geometry of confinement. Our experiments are performed on elastomeric sheets immersed in a fluid, so that the effects of plasticity and friction are suppressed. When the sheet is crumpled either axially or radially within a cylinder, we find that the sheet aligns with the flat or the curved wall, depending on the aspect ratio of the cylinder. Nematic correlations develop between the normals of the sheets at relatively low volume fractions and the crumpled object has large density fluctuations corresponding to the stacking of parallel sheets. The aligning effect of the wall breaks symmetry and selects the direction of ordering

Quasi-random numbers for copula models

The present work addresses the question how sampling algorithms for commonly applied copula models can be adapted to account for quasi-random numbers. Besides sampling methods such as the conditional distribution method (based on a one-to-one transformation), it is also shown that typically faster sampling methods (based on stochastic representations) can be used to improve upon classical Monte Carlo methods when pseudo-random number generators are replaced by quasi-random number generators. This opens the door to quasi-random numbers for models well beyond independent margins or the multivariate normal distribution. Detailed examples (in the context of finance and insurance), illustrations and simulations are given and software has been developed and provided in the R packages copula and qrng

Ulysse pris dans les glaces : odyssées de brume et de neige

Ulysse pris dans les glaces : odyssées de brume et de neig

Political security in the Barents Region

Peer reviewe

Indigenous peoples right to self-determination and the principle of state sovereignty over natural resources: A human rights approach and its constructive ambiguity

The chapter revisits the evolution of international law concerning the development of the principle of Permanent Sovereignty over Natural Resources and its interaction with the rights of Indigenous peoples to self-determination. In this light, the analysis describes how international law concerning the right to natural resources shifted from a state-centred interpretation of the right to dispose of natural resources towards a human rights-centred approach, which includes the rights of Indigenous peoples and the correlative duties of states to guarantee these rights. In this regard, this chapter posits that international law supports a human rights approach to the right to control natural resources, which seeks to conciliate Indigenous peoples' rights to self-determination with state sovereignty over governance of land and resources. This chapter concludes that this development is based on a constructive ambiguity that mediates the conflicting relation between Indigenous peoples and states, but which does not resolve all conflicts.Peer reviewe