446 research outputs found
Reliability and Hardware Implementation of Rank Modulation Flash Memory
We review a novel data representation scheme for NAND flash memory named rank modulation (RM), and discuss its hardware implementation. We show that under the normal threshold voltage (Vth) variations, RM has intrinsic read reliability advantage over conventional multiple-level cells. Test results demonstrating superior reliability using commercial flash chips are reviewed and discussed. We then present a read method based on relative sensing time, which can obtain the rank of all cells in the group in one read cycle. The improvement in reliability and read speed enable similar program-and-verify time in RM as that of conventional MLC flash
Generalized polar transforms of spacelike isothermic surfaces
In this paper, we generalize the polar transforms of spacelike isothermic
surfaces in to n-dimensional pseudo-Riemannian space forms . We
show that there exist polar spacelike isothermic surfaces derived from a
spacelike isothermic surface in , which are into ,
or depending on or . The polar
isothermic surfaces can be characterized as generalized surfaces with null
minimal sections. We also prove that if both the original surface and its
polar surface are closed immersion, then they have the same Willmore
functional. As examples, we discuss some product surfaces and compute the
polar transforms of them. In the end, we derive the permutability theorems
for polar transforms and Darboux transform and spectral transform of
isothermic surfaces.Comment: 12 pages, to appear in J. Geom. Ph
Reliability and Hardware Implementation of Rank Modulation Flash Memory
We review a novel data representation scheme for NAND flash memory named rank modulation (RM), and discuss its hardware implementation. We show that under the normal threshold voltage (Vth) variations, RM has intrinsic read reliability advantage over conventional multiple-level cells. Test results demonstrating superior reliability using commercial flash chips are reviewed and discussed. We then present a read method based on relative sensing time, which can obtain the rank of all cells in the group in one read cycle. The improvement in reliability and read speed enable similar program-and-verify time in RM as that of conventional MLC flash
(1+3) Covariant Dynamics of Scalar Perturbations in Braneworlds
We discuss the dynamics of linear, scalar perturbations in an almost
Friedmann-Robertson-Walker braneworld cosmology of Randall-Sundrum type II
using the 1+3 covariant approach. We derive a complete set of frame-independent
equations for the total matter variables, and a partial set of equations for
the non-local variables which arise from the projection of the Weyl tensor in
the bulk. The latter equations are incomplete since there is no propagation
equation for the non-local anisotropic stress. We supplement the equations for
the total matter variables with equations for the independent constituents in a
cold dark matter cosmology, and provide solutions in the high and low-energy
radiation-dominated phase under the assumption that the non-local anisotropic
stress vanishes. These solutions reveal the existence of new modes arising from
the two additional non-local degrees of freedom. Our solutions should prove
useful in setting up initial conditions for numerical codes aimed at exploring
the effect of braneworld corrections on the cosmic microwave background (CMB)
power spectrum. As a first step in this direction, we derive the covariant form
of the line of sight solution for the CMB temperature anisotropies in
braneworld cosmologies, and discuss possible mechanisms by which braneworld
effects may remain in the low-energy universe.Comment: 22 pages replaced with additional references and minor corrections in
Revtex4, and accepted for publication in Phys. Rev.
Conductive composites for oligonucleotide detection
© 2017 The Authors A new method for oligonucleotide detection is presented based on oligonucleotide cross-linked polymer composites. Conductive carbon nanoparticles are incorporated into a DNA-functionalised polymer, containing partially complementary oligonucleotide cross-linkers, which is polymerised in situ upon interdigitated electrodes. In the presence of an aqueous solution of a specific analyte oligonucleotide sequence, the cross-linkers are cleaved, leading to increased swelling. As the polymer swells the relative density of the conductive particles decreases, leading to an easily measurable decrease in electrical conductivity. We demonstrate that such are capable of discriminating between analyte and control solutions, with single-base specificity, in under 3 min. The lower detection limit of these composites is of the order of 10 nM. The swelling characteristics of these composites is confirmed by optical imaging and the effects of varying temperature upon such composites are also reported
Cosmological Perturbations in Brane-World Theories: Formalism
We develop a gauge-invariant formalism to describe metric perturbations in
five-dimensional brane-world theories. In particular, this formalism applies to
models originating from heterotic M-theory. We introduce a generalized
longitudinal gauge for scalar perturbations. As an application, we discuss some
aspects of the evolution of fluctuations on the brane. Moreover, we show how
the five-dimensional formalism can be matched to the known four-dimensional one
in the limit where an effective four-dimensional description is appropriate.Comment: 16 pages, no figure, matches version to appear in PR
Small Scale Structure Formation in Chameleon Cosmology
Chameleon fields are scalar fields whose mass depends on the ambient matter
density. We investigate the effects of these fields on the growth of density
perturbations on sub-galactic scales and the formation of the first dark matter
halos. Density perturbations on comoving scales go non--linear
and collapse to form structure much earlier than in standard CDM
cosmology. The resulting mini-halos are hence more dense and resilient to
disruption. We therefore expect (provided that the density perturbations on
these scales have not been erased by damping processes) that the dark matter
distribution on small scales would be more clumpy in chameleon cosmology than
in the CDM model.Comment: 13 pages, 4 figure
Iterative algorithms for finding a common solution of system of the set of variational inclusion problems and the set of fixed point problems
Viscosity iterative algorithm for variational inequality problems and fixed point problems in a real q-uniformly smooth Banach space
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