3,066 research outputs found
Large Margin Multiclass Gaussian Classification with Differential Privacy
As increasing amounts of sensitive personal information is aggregated into
data repositories, it has become important to develop mechanisms for processing
the data without revealing information about individual data instances. The
differential privacy model provides a framework for the development and
theoretical analysis of such mechanisms. In this paper, we propose an algorithm
for learning a discriminatively trained multi-class Gaussian classifier that
satisfies differential privacy using a large margin loss function with a
perturbed regularization term. We present a theoretical upper bound on the
excess risk of the classifier introduced by the perturbation.Comment: 14 page
Essential Differences between and Axis Tunneling and Zero Bias Conductance in the Cuprates
The peculiarities in tunneling characteristics have been studied in the light
of the controversy between s-wave and d-wave character of High
superconductivity. We show that anisotropic s-wave gap has the same low voltage
power law conductance and two peak structure in the density of states as d-wave
superconductors. The asymmetric tunneling conductance and zero bias conductance
for the c-axis tunneling is shown to occur because of finite band splitting
coming from the interlayer hopping parameter.Comment: revtex version 3.0, 13 pages 4 figures available on request from
[email protected] - IP/BBSR/94-2
Tunable Brownian Vortex at the Interface
A general kind of Brownian vortexes are demonstrated by applying an external
nonconservative force field to a colloidal particle bound by a conservative
optical trapping force at a liquid-air interface. As the liquid medium is
translated at a constant velocity with the bead trapped at the interface, the
drag force near the surface provide enough rotational component to bias the
particle's thermal fluctuations in a circulatory motion. The interplay between
the thermal fluctuations and the advection of the bead in constituting the
vortex motions is studied, inferring that the angular velocity of the
circulatory motion offers a comparative measure of the interface fluctuations.Comment: Accepted for publication in Phys. Rev.
Optical tweezer for probing erythrocyte membrane deformability
We report that the average rotation speed of optically trapped crenated
erythrocytes is direct signature of their membrane deformability. When placed
in hypertonic buffer, discocytic erythrocytes are subjected to crenation. The
deformation of cells brings in chirality and asymmetry in shape that make them
rotate under the scattering force of a linearly polarized optical trap. A
change in the deformability of the erythrocytes, due to any internal or
environmental factor, affects the rotation speed of the trapped crenated cells.
Here we show how the increment in erythrocyte membrane rigidity with adsorption
of ions can be exhibited through this approach.Comment: Published in Appl. Phys. Lett. 95, 233703 (2009); Two supplementary
multimedia files are available at the journal page:
http://link.aip.org/mm/APPLAB/1.3272269/083949aplv1.mov and
http://link.aip.org/mm/APPLAB/1.3272269/083949aplv2.mo
Fluctuating hydrodynamics for a discrete Gross-Pitaevskii equation: mapping to Kardar-Parisi-Zhang universality class
We show that several aspects of the low-temperature hydrodynamics of a
discrete Gross-Pitaevskii equation (GPE) can be understood by mapping it to a
nonlinear version of fluctuating hydrodynamics. This is achieved by first
writing the GPE in a hydrodynamic form of a continuity and an Euler equation.
Respecting conservation laws, dissipation and noise due to the system's chaos
are added, thus giving us a nonlinear stochastic field theory in general and
the Kardar-Parisi-Zhang (KPZ) equation in our particular case. This mapping to
KPZ is benchmarked against exact Hamiltonian numerics on discrete GPE by
investigating the non-zero temperature dynamical structure factor and its
scaling form and exponent. Given the ubiquity of the Gross-Pitaevskii equation
(a.k.a. nonlinear Schrodinger equation), ranging from nonlinear optics to cold
gases, we expect this remarkable mapping to the KPZ equation to be of paramount
importance and far reaching consequences.Comment: 6 pages, 2 figure
Pays pauvres très endettés, mécanismes et éléments d’évaluation.
agence de notation, AID, annulation de dette, Banque mondiale, Brady, Club de Londres, Club de Paris, DSA, DSRP, dette souveraine, évaluation, FMI, FRPC, initiative PPTE/HIPC (Highly Indebted Poor Countries), termes de Naples, rééchelonnement, soutenabilité, tiers monde, Zone franc.
Growth of fat slits and dispersionless KP hierarchy
A "fat slit" is a compact domain in the upper half plane bounded by a curve
with endpoints on the real axis and a segment of the real axis between them. We
consider conformal maps of the upper half plane to the exterior of a fat slit
parameterized by harmonic moments of the latter and show that they obey an
infinite set of Lax equations for the dispersionless KP hierarchy. Deformation
of a fat slit under changing a particular harmonic moment can be treated as a
growth process similar to the Laplacian growth of domains in the whole plane.
This construction extends the well known link between solutions to the
dispersionless KP hierarchy and conformal maps of slit domains in the upper
half plane and provides a new, large family of solutions.Comment: 26 pages, 6 figures, typos correcte
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