942 research outputs found
How To Build an Undervoting Machine: Lessons from an Alternative Ballot Design
Despite the importance of usability in ensuring election integrity, it remains an under-studied aspect of voting systems.
Voting computers (a.k.a. DREs) offer the opportunity to present ballots to voters in novel ways, yet this space has not been
systematically explored. We constructed a DRE that, unlike most commercial DREs, does not require voters to view every
race, but instead starts at the “review screen” and lets voters directly navigate to races. This was compared with a more
traditional, sequentially-navigated, DRE. The direct access navigation model had two effects, both of which were quite
large. First, voters made omission (undervote) errors markedly more often. Second, voters who were free to choose who to
vote for chose to vote in substantially fewer races. We also examined the relationship between the true error rate—which is
not observable in real elections—and the residual vote rate, a measure of effectiveness commonly used for real elections.
Replicating the findings of [Campbell and Byrne 2009a], the mean residual vote rate was close to the mean true error rate,
but the correlation between these measures was low, suggesting a loose coupling between these two measures
Post-Election Auditing: Effects of Procedure and Ballot Type on Manual Counting Accuracy, Efficiency, and Auditor Satisfaction and Confidence
Universal analytic properties of noise. Introducing the J-Matrix formalism
We propose a new method in the spectral analysis of noisy time-series data
for damped oscillators. From the Jacobi three terms recursive relation for the
denominators of the Pad\'e Approximations built on the well-known Z-transform
of an infinite time-series, we build an Hilbert space operator, a J-Operator,
where each bound state (inside the unit circle in the complex plane) is simply
associated to one damped oscillator while the continuous spectrum of the
J-Operator, which lies on the unit circle itself, is shown to represent the
noise. Signal and noise are thus clearly separated in the complex plane. For a
finite time series of length 2N, the J-operator is replaced by a finite order
J-Matrix J_N, having N eigenvalues which are time reversal covariant. Different
classes of input noise, such as blank (white and uniform), Gaussian and pink,
are discussed in detail, the J-Matrix formalism allowing us to efficiently
calculate hundreds of poles of the Z-transform. Evidence of a universal
behaviour in the final statistical distribution of the associated poles and
zeros of the Z-transform is shown. In particular the poles and zeros tend, when
the length of the time series goes to infinity, to a uniform angular
distribution on the unit circle. Therefore at finite order, the roots of unity
in the complex plane appear to be noise attractors. We show that the
Z-transform presents the exceptional feature of allowing lossless undersampling
and how to make use of this property. A few basic examples are given to suggest
the power of the proposed method.Comment: 14 pages, 8 figure
Facebook's Mobile Career
At the end of its first decade, Facebook’s identity, popularity, and characteristics are shaped in important ways by its becoming a form of mobile media, as much as it as platform associated with Internet and social media. This paper seeks to explore and understand Facebook as the important force in mobile media and communication it now is. It draws upon and combines perspectives from technology production, design, and economy, as well as user adoption, consumption, practices, affect, emotion, and resistance. The paper discusses the beginnings of mobile Facebook, and the early adoption of mobile Facebook associated with the rise of smartphones. The second part of the paper explores Facebook’s integration with photography (with Instagram) and social games (such as Zynga’s Farmville). The paper argues that Facebook’s mobile career is an accomplishment that has distinctively melded evolving affordances, everyday use across a wide range of settings, as well as political economies, corporate strategy, and design.Australian Research Counci
Vibrational Spectroscopic Investigation of Molecular Crystals of Methylmercury(II) Halides
A nearly full assignment of the vibrational modes of methylmercury halide crystals has been proposed. Factor group analysis has been used to derive the vibrational selection rules for the lattice modes. It is concluded that the D2hU structure with four molecules in the unit cell. Lattice modes for CH.-sHgl and CD.-jHgl can be assigned on the basis of C2hU substructure with two molecules per unit cell.
The bromide gave an ultra-low wavenumber band (7.0 cm-1) which we were unable to assign. Force constants have been calculated on the basis of a primitive unit cell (containig two molecules). The internal HgX stretching force constants 2.112, 1.658, 1.507 and 1.347 N cm-1 and the transverse translatory force constants 0.719, 0.364, 0.266 and 0.218 N cm-1 obtained for fluoride, chloride, bromide, and iodide, respectively, show strong dependence on the kind of halide
A burst search for gravitational waves from binary black holes
Compact binary coalescence (CBC) is one of the most promising sources of
gravitational waves. These sources are usually searched for with matched
filters which require accurate calculation of the GW waveforms and generation
of large template banks. We present a complementary search technique based on
algorithms used in un-modeled searches. Initially designed for detection of
un-modeled bursts, which can span a very large set of waveform morphologies,
the search algorithm presented here is constrained for targeted detection of
the smaller subset of CBC signals. The constraint is based on the assumption of
elliptical polarisation for signals received at the detector. We expect that
the algorithm is sensitive to CBC signals in a wide range of masses, mass
ratios, and spin parameters. In preparation for the analysis of data from the
fifth LIGO-Virgo science run (S5), we performed preliminary studies of the
algorithm on test data. We present the sensitivity of the search to different
types of simulated CBC waveforms. Also, we discuss how to extend the results of
the test run into a search over all of the current LIGO-Virgo data set.Comment: 12 pages, 4 figures, 2 tables, submitted for publication in CQG in
the special issue for the conference proceedings of GWDAW13; corrected some
typos, addressed some minor reviewer comments one section restructured and
references updated and correcte
Two-photon quantum walks in an elliptical direct-write waveguide array
Integrated optics provides an ideal test bed for the emulation of quantum
systems via continuous-time quantum walks. Here we study the evolution of
two-photon states in an elliptic array of waveguides. We characterise the
photonic chip via coherent-light tomography and use the results to predict
distinct differences between temporally indistinguishable and distinguishable
two-photon inputs which we then compare with experimental observations. Our
work highlights the feasibility for emulation of coherent quantum phenomena in
three-dimensional waveguide structures.Comment: 8 pages, 7 figure
Challenging Perceptions of Disability through Performance Poetry Methods: The "Seen but Seldom Heard" Project.
This paper considers performance poetry as a method to explore lived experiences
of disability. We discuss how poetic inquiry used within a participatory arts-based
research framework can enable young people to collectively question society’s
attitudes and actions towards disability. Poetry will be considered as a means to
develop a more accessible and effective arena in which young people with direct
experience of disability can be empowered to develop new skills that enable them
to tell their own stories. Discussion of how this can challenge audiences to critically reflect upon their own perceptions of disability will also be developed
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