38,740 research outputs found
Exact solutions for chemical concentration waves of self-propelling camphor particles racing on a ring: A novel potential dynamics perspective
A potential dynamics approach is developed to determine the periodic standing
and traveling wave patterns associated with self-propelling camphor objects
floating on ring-shaped water channels. Exact solutions of the wave patterns
are derived. The bifurcation diagram describing the transition between the
immobile and self-propelling modes of camphor objects is derived
semi-analytically. The bifurcation is of a pitchfork type which is consistent
with earlier theoretical work in which natural boundary conditions have been
considered.Comment: 12 pages, 4 figure
Synchronization and anchoring of two non-harmonic canonical-dissipative oscillators via Smorodinsky-Winternitz potentials
Two non-harmonic canonical-dissipative limit cycle oscillators are considered
that oscillate in one-dimensional Smorodinsky-Winternitz potentials. It is
shown that the standard approach of the canonical-dissipative framework to
introduce dissipative forces leads naturally to a coupling force between the
oscillators that establishes synchronization. The non-harmonic character of the
limit cycles in the context of anchoring, the phase difference between the
synchronized oscillators, and the degree of synchronization are studied in
detail.Comment: 7 pages, 1 figur
Habitats and Spider Prey of \u3ci\u3eDipogon Sayi Sayi\u3c/i\u3e (Hymenoptera: Pompilidae) in Washington County, Maine
Spider wasps were reared from three types of trap-nests deployed in strip-clearcut areas of a spruce-fir-mixed hardwood forest of Maine. Collections of Dipogon sayi sayi from Mooseborn National Wildlife Refuge, Washington County, represent the easternmost records for the United States. Spider prey included females of Misumena vatia, Xysticus emertoni (new prey record), and X. punctatus, and juveniles and penultimate males of Xysticus sp. We found no evidence of nest-site competition between spider wasps and eumenid wasps (Hymenoptera: Eumenidae) that prey on spruce budwornl, Choristoneura fumiferana, when available nesting sites ranged from 320 to 4400
Symbol detection in online handwritten graphics using Faster R-CNN
Symbol detection techniques in online handwritten graphics (e.g. diagrams and
mathematical expressions) consist of methods specifically designed for a single
graphic type. In this work, we evaluate the Faster R-CNN object detection
algorithm as a general method for detection of symbols in handwritten graphics.
We evaluate different configurations of the Faster R-CNN method, and point out
issues relative to the handwritten nature of the data. Considering the online
recognition context, we evaluate efficiency and accuracy trade-offs of using
Deep Neural Networks of different complexities as feature extractors. We
evaluate the method on publicly available flowchart and mathematical expression
(CROHME-2016) datasets. Results show that Faster R-CNN can be effectively used
on both datasets, enabling the possibility of developing general methods for
symbol detection, and furthermore, general graphic understanding methods that
could be built on top of the algorithm.Comment: Submitted to DAS-201
How does insect resistance to phosphine affect insect control costs of stored-grain?
Crop Production/Industries,
Quantum Mechanical Treatment of the Problem of Constraints in Nonextensive Formalism Revisited
The purity of Werner state in nonextensive formalism associated with two
different constraints has been calculated in a previous paper by G. B. Bagci et
al. [G. B. Bagci et al., Int. J. Mod. Phys. 20, 2085 (2006)]. Two different
results have been obtained corresponding to ordinary probability and escort
probability whereas the former has been shown to result in negative values
thereby leading authors to deduce the advantage of escort probabilities over
ordinary probabilities. However, this results have been only for a limited
interval of q values which lie between 0 and 1. In this paper, we solve the
same problem for all values of nonextensive index q by using a perturbative
approach and show that the simultaneous use of both types of constraint is
necessary in order to obtain the solution for whole spectrum of nonextensive
index. In this sense, the existence of these different constraints in
nonextensive formalism must not be seen as a deficiency in the formalism but
rather must be welcomed as a means of providing solution for all values of
parameter q.Comment: 7 page
Theory of strong localization effects of light in disordered loss or gain media
We present a systematical theory for the interplay of strong localization
effects and absorption or gain of classical waves in 3-dimensional, disordered
dielectrics. The theory is based on the selfconsistent Cooperon resummation,
implementing the effects of energy conservation and its absorptive or emissive
corrections by an exact, generalized Ward identity. Substantial
renormalizations are found, depending on whether the absorption/gain occurs in
the scatterers or in the background medium. We find a finite, gain-induced
correlation volume which may be significantly smaller than the scale set by the
scattering mean free path, even if there are no truly localized modes. Possible
consequences for coherent feedback in random lasers as well as the possibility
of oscillatory in time behavior induced by sufficiently strong gain are
discussed.Comment: Published versio
A Divergence-Free Upwind Code for Multidimensional Magnetohydrodynamic Flows
A description is given for preserving {\bmsy\nabla}\cdot{\vec B}=0 in a
magnetohydrodynamic (MHD) code that employs the upwind, Total Variation
Diminishing (TVD) scheme and the Strang-type operator splitting for
multi-dimensionality. The method is based on the staggered mesh technique to
constrain the transport of magnetic field: the magnetic field components are
defined at grid interfaces with their advective fluxes on grid edges, while
other quantities are defined at grid centers. The magnetic field at grid
centers for the upwind step is calculated by interpolating the values from grid
interfaces. The advective fluxes on grid edges for the magnetic field evolution
are calculated from the upwind fluxes at grid interfaces. Then, the magnetic
field can be maintained with {\bmsy\nabla}\cdot{\vec B}=0 exactly, if this is
so initially, while the upwind scheme is used for the update of fluid
quantities. The correctness of the code is demonstrated through tests comparing
numerical solutions either with analytic solutions or with numerical solutions
from the code using an explicit divergence-cleaning method. Also the robustness
is shown through tests involving realistic astrophysical problems.Comment: 15 pages of text, 8 figures (in degraded gif format), to appear in
The Astrophysical Journal (Dec. 10, 1998), original quality figures available
via anonymous ftp at ftp://ftp.msi.umn.edu/pub/users/twj/mhddivb5.uu or
ftp://canopus.chungnam.ac.kr/ryu/mhddivb5.u
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