7,283 research outputs found
Invisible Pixels Are Dead, Long Live Invisible Pixels!
Privacy has deteriorated in the world wide web ever since the 1990s. The
tracking of browsing habits by different third-parties has been at the center
of this deterioration. Web cookies and so-called web beacons have been the
classical ways to implement third-party tracking. Due to the introduction of
more sophisticated technical tracking solutions and other fundamental
transformations, the use of classical image-based web beacons might be expected
to have lost their appeal. According to a sample of over thirty thousand images
collected from popular websites, this paper shows that such an assumption is a
fallacy: classical 1 x 1 images are still commonly used for third-party
tracking in the contemporary world wide web. While it seems that ad-blockers
are unable to fully block these classical image-based tracking beacons, the
paper further demonstrates that even limited information can be used to
accurately classify the third-party 1 x 1 images from other images. An average
classification accuracy of 0.956 is reached in the empirical experiment. With
these results the paper contributes to the ongoing attempts to better
understand the lack of privacy in the world wide web, and the means by which
the situation might be eventually improved.Comment: Forthcoming in the 17th Workshop on Privacy in the Electronic Society
(WPES 2018), Toronto, AC
Theory for the density of interacting quasi-localised modes in amorphous solids
Quasi-localised modes appear in the vibrational spectrum of amorphous solids
at low-frequency. Though never formalised, these modes are believed to have a
close relationship with other important local excitations, including shear
transformations and two-level systems. We provide a theory for their frequency
density, , that establishes this link for
systems at zero temperature under quasi-static loading. It predicts two regimes
depending on the density of shear transformations (with
the additional stress needed to trigger a shear transformation). If
, and a finite fraction of quasi-localised modes form
shear transformations, whose amplitudes vanish at low frequencies. If
, and all quasi-localised modes form shear
transformations with a finite amplitude at vanishing frequencies. We confirm
our predictions numerically
Interindustry Wage Differentials in Australia, 1947-54
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91914/1/Kmenta-Inter-Industry_Wage.pd
A composite system approach to aircraft cabin fire safety
The thermochemical and flammability characteristics of two polymeric composites currently in use and seven others being considered for use as aircraft interior panels are described. The properties studied included: (1) limiting oxygen index of the composite constituents; (2) fire containment capability of the composite; (3) smoke evolution from the composite; (4) thermogravimetric analysis; (5) composition of the volatile products of thermal degradation; and (6) relative toxicity of the volatile products of pyrolysis. The performance of high temperature laminating resins such as bismaleimides is compared with the performance of phenolics and epoxies. The relationship of increased fire safety with the use of polymers with high anaerobic char yield is shown. Processing parameters of one of the baremaleimide composites are detailed
The Zipf law for random texts with unequal probabilities of occurrence of letters and the Pascal pyramid
We model the generation of words with independent unequal probabilities of
occurrence of letters. We prove that the probability of occurrence of
words of rank has a power asymptotics. As distinct from the paper published
earlier by B. Conrad and M. Mitzenmacher, we give a brief proof by elementary
methods and obtain an explicit formula for the exponent of the power law.Comment: 4 page
Interaction and dynamical binding of spin waves or excitons in quantum Hall systems
Interaction between spin waves (or excitons) moving in the lowest Landau
level is studied using numerical diagonalization. Becuse of complicated
statistics obeyed by these composite particles, their effective interaction is
completely different from the dipole-dipole interaction predicted in the model
of independent (bosonic) waves. In particular, spin waves moving in the same
direction attract one another which leads to their dynamical binding. The
interaction pseudopotentials V_[up,up](k) and V_[up,down](k) for two spin waves
with equal wavevectors k and moving in the same or opposite directions have
been calculated and shown to obey power laws V(k) ~ k^alpha at small k. A high
value of alpha_[up,up]~4 explains the occurrence of linear bands in the spin
excitation spectra of quantum Hall droplets.Comment: 6 pages, 4 figures, submitted to PR
Random Walks in Local Dynamics of Network Losses
We suggest a model for data losses in a single node of a packet-switched
network (like the Internet) which reduces to one-dimensional discrete random
walks with unusual boundary conditions. The model shows critical behavior with
an abrupt transition from exponentially small to finite losses as the data
arrival rate increases. The critical point is characterized by strong
fluctuations of the loss rate. Although we consider the packet arrival being a
Markovian process, the loss rate exhibits non-Markovian power-law correlations
in time at the critical point.Comment: 4 pages, 2 figure
Temporal Correlations of Local Network Losses
We introduce a continuum model describing data losses in a single node of a
packet-switched network (like the Internet) which preserves the discrete nature
of the data loss process. {\em By construction}, the model has critical
behavior with a sharp transition from exponentially small to finite losses with
increasing data arrival rate. We show that such a model exhibits strong
fluctuations in the loss rate at the critical point and non-Markovian power-law
correlations in time, in spite of the Markovian character of the data arrival
process. The continuum model allows for rather general incoming data packet
distributions and can be naturally generalized to consider the buffer server
idleness statistics
Enhanced Support for High Intensity Users of the Criminal Justice System – an evaluation of mental health nurse input into Integrated Offender Management Services in the North East of England
The current UK Government’s focus on the development of services to manage and support offenders with mental health problems has resulted in a number of innovative project developments. This research examines a service development in the North East of England which co-located Mental Health nurses with two Integrated Offender Management teams. While not solving all problems, the benefits of co-location were clear – although such innovations are now at risk from government changes which will make Integrated Offender Management the responsibility of new providers without compelling them to co-operate with health services
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