10,783 research outputs found
On the characterization of multiaxial data in terms of the strain energy concept
Continuous media theory for characterization of multiaxial mechanical behavior of solid propellants - strain energy concep
Learning and coordinating in a multilayer network
We introduce a two layer network model for social coordination incorporating
two relevant ingredients: a) different networks of interaction to learn and to
obtain a payoff , and b) decision making processes based both on social and
strategic motivations. Two populations of agents are distributed in two layers
with intralayer learning processes and playing interlayer a coordination game.
We find that the skepticism about the wisdom of crowd and the local
connectivity are the driving forces to accomplish full coordination of the two
populations, while polarized coordinated layers are only possible for
all-to-all interactions. Local interactions also allow for full coordination in
the socially efficient Pareto-dominant strategy in spite of being the riskier
one
Competition and dual users in complex contagion processes
We study the competition of two spreading entities, for example innovations,
in complex contagion processes in complex networks. We develop an analytical
framework and examine the role of dual users, i.e. agents using both
technologies. Searching for the spreading transition of the new innovation and
the extinction transition of a preexisting one, we identify different phases
depending on network mean degree, prevalence of preexisting technology, and
thresholds of the contagion process. Competition with the preexisting
technology effectively suppresses the spread of the new innovation, but it also
allows for phases of coexistence. The existence of dual users largely modifies
the transient dynamics creating new phases that promote the spread of a new
innovation and extinction of a preexisting one. It enables the global spread of
the new innovation even if the old one has the first-mover advantage.Comment: 9 pages, 4 figure
Multilayer coevolution dynamics of the nonlinear voter model
We study a coevolving nonlinear voter model on a two-layer network.
Coevolution stands for coupled dynamics of the state of the nodes and of the
topology of the network in each layer. The plasticity parameter p measures the
relative time scale of the evolution of the states of the nodes and the
evolution of the network by link rewiring. Nonlinearity of the interactions is
taken into account through a parameter q that describes the nonlinear effect of
local majorities, being q = 1 the marginal situation of the ordinary voter
model. Finally the connection between the two layers is measured by a degree of
multiplexing `. In terms of these three parameters, p, q and ` we find a rich
phase diagram with different phases and transitions. When the two layers have
the same plasticity p, the fragmentation transition observed in a single layer
is shifted to larger values of p plasticity, so that multiplexing avoids
fragmentation. Different plasticities for the two layers lead to new phases
that do not exist in a coevolving nonlinear voter model in a single layer,
namely an asymmetric fragmented phase for q > 1 and an active shattered phase
for q
1, we can find two different transitions by increasing the plasticity
parameter, a first absorbing transition with no fragmentation and a subsequent
fragmentation transition
Stochastic Effects in Physical Systems
A tutorial review is given of some developments and applications of
stochastic processes from the point of view of the practicioner physicist. The
index is the following: 1.- Introduction 2.- Stochastic Processes 3.- Transient
Stochastic Dynamics 4.- Noise in Dynamical Systems 5.- Noise Effects in
Spatially Extended Systems 6.- Fluctuations, Phase Transitions and
Noise-Induced Transitions.Comment: 93 pages, 36 figures, LaTeX. To appear in Instabilities and
Nonequilibrium Structures VI, E. Tirapegui and W. Zeller,eds. Kluwer Academi
Competing contagion processes: Complex contagion triggered by simple contagion
Empirical evidence reveals that contagion processes often occur with
competition of simple and complex contagion, meaning that while some agents
follow simple contagion, others follow complex contagion. Simple contagion
refers to spreading processes induced by a single exposure to a contagious
entity while complex contagion demands multiple exposures for transmission.
Inspired by this observation, we propose a model of contagion dynamics with a
transmission probability that initiates a process of complex contagion. With
this probability nodes subject to simple contagion get adopted and trigger a
process of complex contagion. We obtain a phase diagram in the parameter space
of the transmission probability and the fraction of nodes subject to complex
contagion. Our contagion model exhibits a rich variety of phase transitions
such as continuous, discontinuous, and hybrid phase transitions, criticality,
tricriticality, and double transitions. In particular, we find a double phase
transition showing a continuous transition and a following discontinuous
transition in the density of adopted nodes with respect to the transmission
probability. We show that the double transition occurs with an intermediate
phase in which nodes following simple contagion become adopted but nodes with
complex contagion remain susceptible.Comment: 9 pages, 4 figure
Means and method of measuring viscoelastic strain Patent
Photographic method for measuring viscoelastic strain in solid propellants and other material
Miniature stress transducer Patent
Miniature solid state, direction sensitive, stress transducer design with bonded semiconductive piezoresistive element for sensing residual stresse
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