2,364,900 research outputs found
Synchronizabilities of Networks: A New index
The random matrix theory is used to bridge the network structures and the
dynamical processes defined on them. We propose a possible dynamical mechanism
for the enhancement effect of network structures on synchronization processes,
based upon which a dynamic-based index of the synchronizability is introduced
in the present paper.Comment: 4pages, 2figure
Point patterns occurring on complex structures in space and space-time: An alternative network approach
This paper presents an alternative approach of analyzing possibly multitype
point patterns in space and space-time that occur on network structures, and
introduces several different graph-related intensity measures. The proposed
formalism allows to control for processes on undirected, directional as well as
partially directed network structures and is not restricted to linearity or
circularity
Large Deviations in Stochastic Heat-Conduction Processes Provide a Gradient-Flow Structure for Heat Conduction
We consider three one-dimensional continuous-time Markov processes on a
lattice, each of which models the conduction of heat: the family of Brownian
Energy Processes with parameter , a Generalized Brownian Energy Process, and
the Kipnis-Marchioro-Presutti process. The hydrodynamic limit of each of these
three processes is a parabolic equation, the linear heat equation in the case
of the BEP and the KMP, and a nonlinear heat equation for the GBEP().
We prove the hydrodynamic limit rigorously for the BEP, and give a formal
derivation for the GBEP().
We then formally derive the pathwise large-deviation rate functional for the
empirical measure of the three processes. These rate functionals imply
gradient-flow structures for the limiting linear and nonlinear heat equations.
We contrast these gradient-flow structures with those for processes describing
the diffusion of mass, most importantly the class of Wasserstein gradient-flow
systems. The linear and nonlinear heat-equation gradient-flow structures are
each driven by entropy terms of the form ; they involve dissipation
or mobility terms of order for the linear heat equation, and a
nonlinear function of for the nonlinear heat equation.Comment: 29 page
Modelling the evaporation of thin films of colloidal suspensions using Dynamical Density Functional Theory
Recent experiments have shown that various structures may be formed during
the evaporative dewetting of thin films of colloidal suspensions. Nano-particle
deposits of strongly branched `flower-like', labyrinthine and network
structures are observed. They are caused by the different transport processes
and the rich phase behaviour of the system. We develop a model for the system,
based on a dynamical density functional theory, which reproduces these
structures. The model is employed to determine the influences of the solvent
evaporation and of the diffusion of the colloidal particles and of the liquid
over the surface. Finally, we investigate the conditions needed for
`liquid-particle' phase separation to occur and discuss its effect on the
self-organised nano-structures
Multistep Parametric Processes in Nonlinear Optics
We present a comprehensive overview of different types of parametric
interactions in nonlinear optics which are associated with simultaneous
phase-matching of several optical processes in quadratic nonlinear media, the
so-called multistep parametric interactions. We discuss a number of
possibilities of double and multiple phase-matching in engineered structures
with the sign-varying second-order nonlinear susceptibility, including (i)
uniform and non-uniform quasi-phase-matched (QPM) periodic optical
superlattices, (ii) phase-reversed and periodically chirped QPM structures, and
(iii) uniform QPM structures in non-collinear geometry, including recently
fabricated two-dimensional nonlinear quadratic photonic crystals. We also
summarize the most important experimental results on the multi-frequency
generation due to multistep parametric processes, and overview the physics and
basic properties of multi-color optical parametric solitons generated by these
parametric interactions.Comment: To be published in Progress in Optic
Absence of split pairs in the cross-correlations of a highly transparent normal metal-superconductor-normal metal electron beam splitter
The nonlocal conductance and the current cross-correlations are investigated
within scattering theory for three-terminal normal metal-superconductor-normal
metal (NSN) hybrid structures. The positive cross-correlations at high
transparency found by M\'elin, Benjamin and Martin [Phys. Rev. B 77, 094512
(2008)] are not due to crossed Andreev reflection. On the other hand, local
processes can be enhanced by reflectionless tunneling but this mechanism has
little influence on nonlocal processes and on current cross-correlations.
Therefore Cooper pair splitting cannot be enhanced by reflectionless tunneling.
Overall, this shows that NSN structures with highly transparent or effectively
highly transparent interfaces are not suited to experimentally producing
entangled split pairs of electrons.Comment: 11 pages, 6 figures, 1 table. arXiv admin note: substantial text
overlap with arXiv:1211.534
Representing functions/procedures and processes/structures for analysis of effects of failures on functions and operations
Current qualitative device and process models represent only the structure and behavior of physical systems. However, systems in the real world include goal-oriented activities that generally cannot be easily represented using current modeling techniques. An extension of a qualitative modeling system, known as functional modeling, which captures goal-oriented activities explicitly is proposed and how they may be used to support intelligent automation and fault management is shown
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