15,998 research outputs found
Magnonic momentum transfer force on domain walls confined in space
Momentum transfer from incoming magnons to a Bloch domain wall is calculated
using one dimensional continuum micromagnetic analysis. Due to the confinement
of the wall in space, the dispersion relation of magnons is different from that
of a single domain. This mismatch of dispersion relations can result in
reflection of magnons upon incidence on the domain wall, whose direct
consequence is a transfer of momentum between magnons and the domain wall. The
corresponding counteraction force exerted on the wall can be used for the
control of domain wall motion through magnonic linear momentum transfer, in
analogy with the spin transfer torque induced by magnonic angular momentum
transfer.Comment: 5 pages, 3 figure, published versio
Semiparametric Additive Transformation Model under Current Status Data
We consider the efficient estimation of the semiparametric additive
transformation model with current status data. A wide range of survival models
and econometric models can be incorporated into this general transformation
framework. We apply the B-spline approach to simultaneously estimate the linear
regression vector, the nondecreasing transformation function, and a set of
nonparametric regression functions. We show that the parametric estimate is
semiparametric efficient in the presence of multiple nonparametric nuisance
functions. An explicit consistent B-spline estimate of the asymptotic variance
is also provided. All nonparametric estimates are smooth, and shown to be
uniformly consistent and have faster than cubic rate of convergence.
Interestingly, we observe the convergence rate interfere phenomenon, i.e., the
convergence rates of B-spline estimators are all slowed down to equal the
slowest one. The constrained optimization is not required in our
implementation. Numerical results are used to illustrate the finite sample
performance of the proposed estimators.Comment: 32 pages, 5 figure
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