814 research outputs found
Features and Cost Comparison of Biologically Inspired Vision Systems
The economic analysis of the advantages of known analogues of biologically inspired systems for
unmanned aerial vehicles (UAVs), quadrocopters, etc
Critical parameters of N-vector spin models on 3d lattices from high temperature series extended to order beta^{21}
High temperature expansions for the free energy, the susceptibility and the
second correlation moment of the classical N-vector model [also denoted as the
O(N) symmetric classical spin Heisenberg model or as the lattice O(N) nonlinear
sigma model] have been extended to order beta^{21} on the simple cubic and the
body centered cubic lattices, for arbitrary N. The series for the second field
derivative of the susceptibility has been extended to order beta^{17}. An
analysis of the newly computed series yields updated estimates of the model's
critical parameters in good agreement with present renormalization group
estimates.Comment: 3 pages, Latex,(fleqn.sty, espcrc2.sty) no figures, contribution to
Lattice'97 to appear in Nucl. Phys. Proc. Supp
Critical behavior of frustrated systems: Monte Carlo simulations versus Renormalization Group
We study the critical behavior of frustrated systems by means of Pade-Borel
resummed three-loop renormalization-group expansions and numerical Monte Carlo
simulations. Amazingly, for six-component spins where the transition is second
order, both approaches disagree. This unusual situation is analyzed both from
the point of view of the convergence of the resummed series and from the
possible relevance of non perturbative effects.Comment: RevTex, 10 pages, 3 Postscript figure
Quasifission and difference in formation of evaporation residues in the O+W and F+Ta reactions
The excitation functions of capture, complete fusion, and evaporation residue
formation in the O+W and F+Ta reactions leading
to the same Pb compound nucleus has been studied theoretically to
explain the experimental data showing more intense yield of evaporation residue
in the former reaction in comparison with that in the latter reaction. The
observed difference is explained by large capture cross section in the former
and by increase of the quasifission contribution to the yield of fission-like
fragments in the F+Ta reaction at large excitation energies. The
probability of compound nucleus formation in the O+W reaction is
larger but compound nuclei formed in both reactions have similar angular
momentum ranges at the same excitation energy. The observed decrease of
evaporation residue cross section normalized to the fusion cross section in the
F+Ta reaction in comparison with the one in the
O+W reaction at high excitation energies is explained by the
increase of hindrance in the formation of compound nucleus connected with more
quick increase of the quasifission contribution in the F induced
reaction. The spin distributions of the evaporation residue cross sections for
the two reactions are also presented.Comment: 11 pages, 5 figure
Monte Carlo renormalization group study of the Heisenberg and XY antiferromagnet on the stacked triangular lattice and the chiral model
With the help of the improved Monte Carlo renormalization-group scheme, we
numerically investigate the renormalization group flow of the antiferromagnetic
Heisenberg and XY spin model on the stacked triangular lattice (STA-model) and
its effective Hamiltonian, 2N-component chiral model which is used in
the field-theoretical studies. We find that the XY-STA model with the lattice
size exhibits clear first-order behavior. We also
find that the renormalization-group flow of STA model is well reproduced by the
chiral model, and that there are no chiral fixed point of
renormalization-group flow for N=2 and 3 cases. This result indicates that the
Heisenberg-STA model also undergoes first-order transition.Comment: v1:15 pages, 15 figures v2:updated references v3:added comments on
the higher order irrelevant scaling variables v4:added results of larger
sizes v5:final version to appear in J.Phys.Soc.Jpn Vol.72, No.
High magnetomechanical coupling on magnetic microwire for sensors with biological applications
In this letter, we report the experimental work carried out to study and improve the magnetomechanical coupling on magnetic microwires. A good magnetoelastic response, with magnetoelastic coupling factor k=0.43, has been obtained by control of both wire diameter and sample microstructure. The study addresses two following aspects: (a) analysis of the suitability of amorphous magnetoelastic microwire as promising tiny sensor element to be used as wireless biosensors as well as environment detectors. In particular, its potential as liquids viscosity sensor has been confirmed. (b) Study, as the first time in this kind of magnetic microwire, of the effects of nanocrystallization on the sample magnetoelastic behavior
Psychogenic dizziness
Psychogenic dizziness is one of the most common types of vertigo. To diagnose psychogenic dizziness is a complex task since it requires a thorough patient examination and exclusion of possible organic causes of dizziness. The paper describes the clinical case of a female patient with phobic postural vertigo, which demonstrates the efficiency of the early diagnosis and adequate therapy of this disease. Combination therapy for psychogenic dizziness, which encompasses different psychotherapeutic procedures, vestibular rehabilitation, and drug therapy, is most effective. Among the medications, vinpocetine is effective in treating patients with cerebrovascular disease. Inappropriate treatment may lead to the progression of psychogenic dizziness, to a considerable deterioration in quality of life, and to obvious social disadaptation. There is a worse treatment prognosis with a longer interval between of disease onset and diagnosis
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