It is pointed out that saturation transients are indispensable for a proper description of sand flux over structured terrain, by applying the model to the windward side of an isolated dune, thereby resolving recently reported discrepancies between field measurements and theoretical predictions.Expand

It is shown that with small changes in the network structure (low cost) the robustness of diverse networks can be improved dramatically whereas their functionality remains unchanged and is useful not only for improving significantly with low cost the robustity of existing infrastructures but also for designing economically robust network systems.Expand

We present a minimal model for the formation and migration of aeolian sand dunes in unidirectional winds. It combines a perturbative description of the turbulent wind velocity field above the dune… Expand

This is an introductory course into some aspects of the physics of granular materials. Three theoretical questions are looked into more detail corresponding to the three hours of the course: I… Expand

The model provides a qualitative understanding of important features of real dunes, such as their longitudinal shape and aspect ratio, the formation of a slip face, the breaking of scale invariance, and the existence of a minimum dune size.Expand

The set of equations is applied to study quantitatively the transition between barchans and parabolic dunes driven by the dimensionless fixation index theta which is the ratio between the dune characteristic erosion rate and vegetation growth velocity.Expand

It is shown that the necessary number of autonomous nodes can be reduced by a factor of five compared to a random choice, and that the transition to abrupt collapse follows tricritical scaling characterized by a set of exponents which is independent on the protection strategy.Expand

An immunization approach based on optimizing the susceptible size is developed, which outperforms the best known strategy based on immunizing the highest-betweenness links or nodes and finds that the network's vulnerability can be significantly reduced.Expand

An expression is deduced for estimating cycles of larger size, which improves previous estimations and is suitable for either monopartite and multipartite networks, and the applicability of such analytical estimations is discussed.Expand

We introduce a fiber bundle model where the interaction among fibers is modeled by an adjustable stress-transfer function that can interpolate between the two limiting cases of load redistribution,… Expand