Mitigation of malicious attacks on networks
- C. Schneider, A. Moreira, J. S. Andrade, S. Havlin, H. Herrmann
- Computer ScienceProceedings of the National Academy of Sciences
- 22 February 2011
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.
Continuum saltation model for sand dunes.
- G. Sauermann, K. Kroy, H. Herrmann
- GeologyPhysical review. E, Statistical, nonlinear, and…
- 24 January 2001
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.
Minimal model for aeolian sand dunes.
- K. Kroy, G. Sauermann, H. Herrmann
- Environmental SciencePhysical review. E, Statistical, nonlinear, and…
- 2 March 2002
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…
Vegetation against dune mobility.
- O. Durán, H. Herrmann
- MathematicsPhysical Review Letters
- 12 September 2006
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.
Granular Matter
- H. Herrmann
- Physics
- 2001
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…
Suppressing epidemics with a limited amount of immunization units.
- C. Schneider, Tamara Mihaljev, S. Havlin, H. Herrmann
- Computer SciencePhysical review. E, Statistical, nonlinear, and…
- 9 February 2011
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.
Giant saltation on Mars
- M. P. Almeida, E. Parteli, J. S. Andrade, H. Herrmann
- Geology, PhysicsProceedings of the National Academy of Sciences
- 29 April 2008
This work calculates the motion of saltating grains by directly solving the turbulent wind field and its interaction with the particles to show that the minimal wind velocity required for saltation on Mars may be surprisingly lower than the aerodynamic minimal threshold measurable in wind tunnels.
Minimal model for sand dunes.
- K. Kroy, G. Sauermann, H. Herrmann
- GeologyPhysical Review Letters
- 24 January 2001
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.
Cycles and clustering in bipartite networks.
- P. Lind, Marta C. González, H. Herrmann
- Computer SciencePhysical review. E, Statistical, nonlinear, and…
- 11 April 2005
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.
Ratcheting of granular materials.
- F. Alonso-marroquin, H. Herrmann
- EngineeringPhysical Review Letters
- 2 May 2003
We investigate the quasistatic mechanical response of soils under cyclic loading using a discrete model of randomly generated convex polygons. This response exhibits a sequence of regimes, each one…
...
...