1,264 research outputs found
Privacy-preserving Twitter-based solution for visually impaired people
Visually impaired people is a big community all over the world. They usually seek help to perform their daily activities such as reading the expired date of food cans or medicine, reading out PIN of a certain ATM Visa, identifying the color of clothes or differentiate between the money notes and other objects with the same shape. A number of IT-based solutions have been proposed to help and assist blind and/or visually impaired people. Generally speaking, these solutions, however, do not support Arabic languages nor protect blind users’ privacy. In this paper, Trusted Blind Society (TBS) mobile application is proposed. It is an android application which allows blind users to recognize their unknown surroundings by utilizing two concepts: social networks sites and friendsourcing. These two concepts were employed by allowing family members and the trusted friends, who are registered on Twitter, to answer blind users’ questions on a real time. The solution is also bilingual, supports (Arabic/English) and allows screen reader using Android talk-back service. The performance of the TBS system was evaluated using loader.io to check its stability under the heavy load and it was tested by a number of blind volunteers and the results showed good performance comparing to most related work
Dynamics of semifluxons in Nb long Josephson 0-pi junctions
We propose, implement and test experimentally long Josephson 0-pi junctions
fabricated using conventional Nb-AlOx-Nb technology. We show that using a pair
of current injectors, one can create an arbitrary discontinuity of the
Josephson phase and in particular a pi-discontinuity, just like in
d-wave/s-wave or in d-wave/d-wave junctions, and study fractional Josephson
vortices which spontaneously appear. Moreover, using such junctions, we can
investigate the \emph{dynamics} of the fractional vortices -- a domain which is
not yet available for natural 0-pi-junctions due to their inherently high
damping. We observe half-integer zero-field steps which appear on the
current-voltage characteristics due to hopping of semifluxons.Comment: Fractional vortices in conventional superconductors ;-
Spectroscopy of a fractional Josephson vortex molecule
In long Josephson junctions with multiple discontinuities of the Josephson
phase, fractional vortex molecules are spontaneously formed. At each
discontinuity point a fractional Josephson vortex carrying a magnetic flux
, Wb being the magnetic flux
quantum, is pinned. Each vortex has an oscillatory eigenmode with a frequency
that depends on and lies inside the plasma gap.
We experimentally investigate the dependence of the eigenfrequencies of a
two-vortex molecule on the distance between the vortices, on their topological
charge and on the bias current applied to the
Josephson junction. We find that with decreasing distance between vortices, a
splitting of the eigenfrequencies occurs, that corresponds to the emergence of
collective oscillatory modes of both vortices. We use a resonant microwave
spectroscopy technique and find good agreement between experimental results and
theoretical predictions.Comment: submitted to Phys. Rev.
GOLIA: an INTEGRAL archive at INAF-IASF Milano
We present the archive of the INTEGRAL data developed and maintained at
INAF-IASF Milano. The archive comprises all the public data currently available
(revolutions 0026-1079, i.e., December 2002 - August 2011). INTEGRAL data are
downloaded from the ISDC Data Centre for Astrophysics, Geneva, on a regular
basis as they become public and a customized analysis using the OSA 9.0
software package is routinely performed on the IBIS/ISGRI data. The scientific
products include individual pointing images and the associated detected source
lists in the 17-30, 30-50, 17-50 and 50-100 keV energy bands, as well as
light-curves binned over 100 s in the 17-30 keV band for sources of interest.
Dedicated scripts to handle such vast datasets and results have been developed.
We make the analysis tools to build such an archive publicly available. The
whole database (raw data and products) enables an easy access to the hard X-ray
long-term behavior of a large sample of sources.Comment: 10 pages, 7 figures, Accepted for publication in the Astronomy and
Computing journa
Non-ideal artificial phase discontinuity in long Josephson 0-kappa-junctions
We investigate the creation of an arbitrary -discontinuity of the
Josephson phase in a long Nb-AlO_x-Nb Josephson junction (LJJ) using a pair of
tiny current injectors, and study the formation of fractional vortices formed
at this discontinuity. The current I_inj, flowing from one injector to the
other, creates a phase discontinuity kappa ~ I_inj. The calibration of
injectors is discussed in detail. The small but finite size of injectors leads
to some deviations of the properties of such a 0-kappa-LJJ from the properties
of a LJJ with an ideal kappa-discontinuity. These experimentally observed
deviations in the dependence of the critical current on I_inj$ and magnetic
field can be well reproduced by numerical simulation assuming a finite injector
size. The physical origin of these deviations is discussed.Comment: Submitted to Phys. Rev. B (12 figures). v 2: refs updated, long eqs
fixed v 3: major changes, fractional vortex dynamics exclude
The omnivorous Tyrolean Iceman: colon contents (meat, cereals, pollen, moss and whipworm) and stable isotope analyses
The contents of the colon of the Tyrolean Iceman who lived Ga. 5300 years ago include muscle fibres, cereal remains, a diversity of pollen, and most notably that of the hop hornbeam (Ostrya carpinifolia) retaining cellular contents, as well as a moss leaf (Neckera complanata) and eggs of the parasitic whipworm (Trichuris trichiura). Based almost solely on stable isotope analyses and ignoring the work on the colon contents, two recently published papers on the Iceman's diet draw ill- founded conclusions about vegetarianism and even veganism. Neither the pollen nor the moss is likely to have been deliberately consumed as food by the Iceman. All the available evidence concerning the Iceman's broad-based diet is reviewed and the significance of the colon contents for matters other than assessment of food intake is outlined
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Homogeneous and heterogeneous distributed classification for pocket data mining
Pocket Data Mining (PDM) describes the full process of analysing data streams in mobile ad hoc distributed environments. Advances in mobile devices like smart phones and tablet computers have made it possible for a wide range of applications to run in such an environment. In this paper, we propose the adoption of data stream classification techniques for PDM. Evident by a thorough experimental study, it has been proved that running heterogeneous/different, or homogeneous/similar data stream classification techniques over vertically partitioned data (data partitioned according to the feature space) results in comparable performance to batch and centralised learning techniques
All-fibre source of amplitude-squeezed light pulses
An all-fibre source of amplitude squeezed solitons utilizing the self-phase
modulation in an asymmetric Sagnac interferometer is experimentally
demonstrated. The asymmetry of the interferometer is passively controlled by an
integrated fibre coupler, allowing for the optimisation of the noise reduction.
We have carefully studied the dependence of the amplitude noise on the
asymmetry and the power launched into the Sagnac interferometer. Qualitatively,
we find good agreement between the experimental results, a semi-classical
theory and earlier numerical calculations [Schmitt etl.al., PRL Vol. 81,
p.2446, (1998)]. The stability and flexibility of this all-fibre source makes
it particularly well suited to applications in quantum information science
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