31,066 research outputs found
Existence for the steady problem of a mixture of two power-law fluids
The steady problem resulting from a mixture of two distinct fluids of
power-law type is analyzed in this work. Mathematically, the problem results
from the superposition of two power laws, one for a constant power-law index
with other for a variable one. For the associated boundary-value problem, we
prove the existence of very weak solutions, provided the variable power-law
index is bounded from above by the constant one. This result requires the
lowest possible assumptions on the variable power-law index and, as a
particular case, extends the existence result by Ladyzhenskaya dated from 1969
to the case of a variable exponent and for all zones of the pseudoplastic
region. In a distinct result, we extend a classical theorem on the existence of
weak solutions to the case of our problem.Comment: 22. arXiv admin note: substantial text overlap with arXiv:1203.679
Parabolic reaction-diffusion systems with nonlocal coupled diffusivity terms
In this work we study a system of parabolic reaction-diffusion equations which are coupled not only through the reaction terms but also by way of nonlocal diffusivity functions. For the associated initial problem, endowed with homogeneous Dirichlet or Neumann boundary conditions, we prove the existence of global solutions. We also prove the existence of local solutions but with less assumptions on the boundedness of the nonlocal terms. The uniqueness result is established next and then we find the conditions under which the existence of strong solutions is assured. We establish several bow-up results for the strong solutions to our problem and we give a criterium for the convergence of these solutions towards a homogeneous state.CAPES [BEX 2478-12-8]; MEC/MCTI/CAPES/CNPq/FAPs, Brazil [71/2013, 88881.030388/2013-01]; Fundacao para a Ciencia e a Tecnologia, Portugal [UID/MAT/04561/2013-2015]info:eu-repo/semantics/publishedVersio
The Second Order Traffic Fine: Temporal Reasoning in European Transport Regulations
We argue that European transport regulations can be formalized within the Sigma^1_1 fragment of monadic second order logic, and possibly weaker fragments including linear temporal logic. We consider several articles in the regulation to verify these claims
Traces of Lorentz symmetry breaking in a Hydrogen atom at ground state
Some traces of a specific Lorentz symmetry breaking scenario in the ground
state of the Hydrogen atom are investigated. It is used standard
Rayleigh-Schr\"odinger perturbation theory in order to obtain the corrections
to the the ground state energy and wave function. It is shown that an induced
four-pole moment arises, due to the Lorentz symmetry breaking. The model
considered is the one studied in reference Eur. Phys. J. C {\bf 74}, 2937
(2014), where the Lorentz symmetry is broken in the electromagnetic sector.Comment: 8 Latex pages, 2 figure
Study on behavioral impedance for route planning techniques from the pedestrian's perspective: some findings and considerations
The multi-disciplinary characteristics of transportation force
a new design of geographic information systems, within which
these characteristics are considered. In this context, geographic
information systems for transportation are the result of the
integration of transportation information systems and conventional
geographic information systems. An interesting research area
in geographic information systems for transportation is constraint
management in route planning algorithms from the pedestrian s
perspective. Constraint management becomes more complex when
route planning takes into account an integrated public transportation
network (i.e. a multimodal network). A study on the theoretical
contextualization and taxonomy of a pedestrian s behavioral
impedance has been developed in order to improve the constraint
management from the pedestrian s perspective. This study entails
strategies of travel reduction by private transport (e.g. travel
by car) through switching to or substitution by alternative
public transport (e.g. travel by walk, bus or rail). The
grounded theory method has been used to develop the proposed
taxonomy. Using the partial results of a questionnaire applied
to a reduced group of people from Barcelona as a starting
point, important data are being collected to define the mathematical
model of the behavioral impedance domain. The goal of this
paper is to provide some considerations about theoretical contextualization
on identification and management of constraints regarding the
behavioral impedance domain from the pedestrian s perspective
within the urban public transportation context. The research
project where this work is included is composed of six major
phases. The first phase represents a continuous bibliographic
review. The second phase was a study on sidewalks in the university
zone of Barcelona. In this phase, an experimental application
has been proposed and the management, map and route modules
have been implemented on the ArcInfo GIS package and C++. This
paper reports the partial work of the third phase, which is
composed of two parts. The first part was a theoretical study on
behavioral impedance for route planning techniques, in which
taxonomy was proposed. The results of the second part are partially
presented in this paper. The fourth (i.e. design and implementation),
fifth (i.e. calibration and validation) and sixth (i.e. generalization
of the results) phases are characterized by the application
of the prototype regarding the multimodal network model for
urban public transportation from the pedestrian s perspective.
The main contribution of this article is the behavioral impedance
taxonomy review from the pedestrian s perspective, which will allow
designing a mathematical model and be used to implement a constraint
management algorithm. Within this context, the proposed taxonomy
could be used to model cost functions more precisely.Postprint (published version
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