10,269 research outputs found
Locating influential nodes via dynamics-sensitive centrality
With great theoretical and practical significance, locating influential nodes
of complex networks is a promising issues. In this paper, we propose a
dynamics-sensitive (DS) centrality that integrates topological features and
dynamical properties. The DS centrality can be directly applied in locating
influential spreaders. According to the empirical results on four real networks
for both susceptible-infected-recovered (SIR) and susceptible-infected (SI)
spreading models, the DS centrality is much more accurate than degree,
-shell index and eigenvector centrality.Comment: 6 pages, 1 table and 2 figure
Digital image processing for automatic lithological mapping using Landsat TM imagery
Imperial Users onl
Hydrodynamics of self-alignment interactions with precession and derivation of the Landau-Lifschitz-Gilbert equation
We consider a kinetic model of self-propelled particles with alignment
interaction and with precession about the alignment direction. We derive a
hydrodynamic system for the local density and velocity orientation of the
particles. The system consists of the conservative equation for the local
density and a non-conservative equation for the orientation. First, we assume
that the alignment interaction is purely local and derive a first order system.
However, we show that this system may lose its hyperbolicity. Under the
assumption of weakly non-local interaction, we derive diffusive corrections to
the first order system which lead to the combination of a heat flow of the
harmonic map and Landau-Lifschitz-Gilbert dynamics. In the particular case of
zero self-propelling speed, the resulting model reduces to the phenomenological
Landau-Lifschitz-Gilbert equations. Therefore the present theory provides a
kinetic formulation of classical micromagnetization models and spin dynamics
Projection method for droplet dynamics on groove-textured surface with merging and splitting
The geometric motion of small droplets placed on an impermeable textured
substrate is mainly driven by the capillary effect, the competition among
surface tensions of three phases at the moving contact lines, and the
impermeable substrate obstacle. After introducing an infinite dimensional
manifold with an admissible tangent space on the boundary of the manifold, by
Onsager's principle for an obstacle problem, we derive the associated parabolic
variational inequalities. These variational inequalities can be used to
simulate the contact line dynamics with unavoidable merging and splitting of
droplets due to the impermeable obstacle. To efficiently solve the parabolic
variational inequality, we propose an unconditional stable explicit boundary
updating scheme coupled with a projection method. The explicit boundary
updating efficiently decouples the computation of the motion by mean curvature
of the capillary surface and the moving contact lines. Meanwhile, the
projection step efficiently splits the difficulties brought by the obstacle and
the motion by mean curvature of the capillary surface. Furthermore, we prove
the unconditional stability of the scheme and present an accuracy check. The
convergence of the proposed scheme is also proved using a nonlinear
Trotter-Kato's product formula under the pinning contact line assumption. After
incorporating the phase transition information at splitting points, several
challenging examples including splitting and merging of droplets are
demonstrated.Comment: 26 page
- âŠ