17,747 research outputs found
A moment problem for discrete nonpositive measures on a finite interval
This article has been made available through the Brunel Open Access Publishing Fund.We will estimate the upper and the lower bounds of the integral ∫01Ω(t)dμ(t), where μ runs over all discrete measures, positive on some cones of generalized convex functions, and satisfying certain moment conditions with respect to a given Chebyshev system. Then we apply these estimations to find the error of optimal shape-preserving interpolation
Modeling the Flux-Charge Relation of Memristor with Neural Network of Smooth Hinge Functions
The memristor was proposed to characterize the flux-charge relation. We propose the generalized flux-charge relation model of memristor with neural network of smooth hinge functions. There is effective identification algorithm for the neural network of smooth hinge functions. The representation capability of this model is theoretically guaranteed. Any functional flux-charge relation of a memristor can be approximated by the model. We also give application examples to show that the given model can approximate the flux-charge relation of existing piecewise linear memristor model, window function memristor model, and a physical memristor device
Myxoid Neurothekeoma of the Nipple
Neurothekeomas are rare benign cutaneous neoplasms of nerve sheath origin. They are primarily found in the superficial soft tissue and are also known as dermal nerve sheath myxomas. They are commonly found on the upper extremities, head and neck followed by trunk. Here is an unusual presentation of neurothekeoma occurring as a polypoidal lesion of the nipple in a young female patient
Investigation on the Tachyonic Neutrino
According to the experimental data, it is still controversial whether the
neutrinos, especially the electron-neutrino and muon-neutrino, can be
considered as the fermionic spinorial tachyons, and there is still no reliable
report on the existence of the right-handed neutrinos. In this letter, we show
that the neutrinos with the single handedness can not be the tachyons, but only
those of the both handedness can be. Several implications of this result are
discussed.Comment: 13 pages, latex, no figure
A Memristor Model with Piecewise Window Function
In this paper, we present a memristor model with piecewise window function, which is continuously differentiable and consists of three nonlinear pieces. By introducing two parameters, the shape of this window function can be flexibly adjusted to model different types of memristors. Using this model, one can easily obtain an expression of memristance depending on charge, from which the numerical value of memristance can be readily calculated for any given charge, and eliminate the error occurring in the simulation of some existing window function models
Comments on `` Black Hole Entropy from Conformal Field Theory in Any Dimension ''
In a recent letter, Carlip proposed a generalization of the
Brown-Henneaux-Strominger construction to any dimension. We present two
criticisms about his formulation.Comment: 4 pages, Enriched version for the accepted one (Phys. Rev. Lett.
Spectral signatures of thermal spin disorder and excess Mn in half-metallic NiMnSb
Effects of thermal spin disorder and excess Mn on the electronic spectrum of
half-metallic NiMnSb are studied using first-principles calculations.
Temperature-dependent spin disorder, introduced within the vector disordered
local moment model, causes the valence band at the point to broaden
and shift upwards, crossing the Fermi level and thereby closing the
half-metallic gap above room temperature. The spectroscopic signatures of
excess Mn on the Ni, Sb, and empty sites (Mn, Mn,
and Mn) are analyzed. Mn is spectroscopically
invisible. The relatively weak coupling of Mn and Mn
spins to the host strongly deviates from the Heisenberg model, and the spin of
Mn is canted in the ground state. While the half-metallic gap is
preserved in the collinear ground state of Mn, thermal spin
disorder of the weakly coupled Mn spins destroys it at low
temperatures. This property of Mn may be the source of the
observed low-temperature transport anomalies.Comment: 5 pages, 7 figures, updated version with minor revisions and an
additional figure, accepted in Phys. Rev. B (Rapid Communication
A survey of ectoparasites of Clarias gariepinus caught from theUniversity of Agriculture Research Fish Farm, Makurdi
Clarias gariepinus caught from University of Agriculture Research Fish Farm, Makurdi were examined for ectoparasites from October – December 2010. Of the one hundred and twenty (120) C. gariepinus examined, 40 (33.3%) were infested and were observed to harbour forty three (43) ectoparasites. Pisciola geometra accounted for 59.1% while Midge larvae accounted for 40.9%. These parasites were observed to occur only on the skin of the infested fish. There was significance difference (P>0.05) in infestation between the sexes of the fish, with male species having relatively higher percentage infection (65.12%) than the female (34.89%). Bigger fishes were observed to have higher ectoparasites than the smaller ones
Use of low-energy hydrogen ion implants in high-efficiency crystalline-silicon solar cells
The use of low-energy hydrogen implants in the fabrication of high-efficiency crystalline silicon solar cells was investigated. Low-energy hydrogen implants result in hydrogen-caused effects in all three regions of a solar cell: emitter, space charge region, and base. In web, Czochralski (Cz), and floating zone (Fz) material, low-energy hydrogen implants reduced surface recombination velocity. In all three, the implants passivated the space charge region recombination centers. It was established that hydrogen implants can alter the diffusion properties of ion-implanted boron in silicon, but not ion-implated arsenic
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