7,292 research outputs found
Entanglement generation in spatially separated systems using quantum walk
We present a novel scheme to generate entanglement between two spatially
separated systems. The scheme makes use of spatial entanglement generated by a
single-particle quantum walk which is used to entangle two spatially separated,
not necessarily correlated, systems. This scheme can be used to entangle any
two systems which can interact with the spatial modes entangled during the
quantum walk evolution. A notable feature is that we can control the quantum
walk dynamics and its ability to localize leads to a substantial control and
improvement in the entanglement output.Comment: 9 pages, 5 figure
Nonlinear dynamic intertwining of rods with self-contact
Twisted marine cables on the sea floor can form highly contorted
three-dimensional loops that resemble tangles. Such tangles or hockles are
topologically equivalent to the plectomenes that form in supercoiled DNA
molecules. The dynamic evolution of these intertwined loops is studied herein
using a computational rod model that explicitly accounts for dynamic
self-contact. Numerical solutions are presented for an illustrative example of
a long rod subjected to increasing twist at one end. The solutions reveal the
dynamic evolution of the rod from an initially straight state, through a
buckled state in the approximate form of a helix, through the dynamic collapse
of this helix into a near-planar loop with one site of self-contact, and the
subsequent intertwining of this loop with multiple sites of self-contact. This
evolution is controlled by the dynamic conversion of torsional strain energy to
bending strain energy or, alternatively by the dynamic conversion of twist (Tw)
to writhe (Wr).
KEY WORDS Rod Dynamics, Self-contact, Intertwining, DNA Supercoiling, Cable
HocklingComment: 35 pages, 9 figures, submitted to Proceedings of the Royal Society A:
Mathematical, Physical and Engineering Science
Optimal stopping times for estimating Bernoulli parameters with applications to active imaging
We address the problem of estimating the parameter of a Bernoulli process. This arises in many applications, including photon-efficient active imaging where each illumination period is regarded as a single Bernoulli trial. We introduce a framework within which to minimize the mean-squared error (MSE) subject to an upper bound on the mean number of trials. This optimization has several simple and intuitive properties when the Bernoulli parameter has a beta prior. In addition, by exploiting typical spatial correlation using total variation regularization, we extend the developed framework to a rectangular array of Bernoulli processes representing the pixels in a natural scene. In simulations inspired by realistic active imaging scenarios, we demonstrate a 4.26 dB reduction in MSE due to the adaptive acquisition, as an average over many independent experiments and invariant to a factor of 3.4 variation in trial budget.Accepted manuscrip
Effects of Sensemaking Translucence on Distributed Collaborative Analysis
Collaborative sensemaking requires that analysts share their information and
insights with each other, but this process of sharing runs the risks of
prematurely focusing the investigation on specific suspects. To address this
tension, we propose and test an interface for collaborative crime analysis that
aims to make analysts more aware of their sensemaking processes. We compare our
sensemaking translucence interface to a standard interface without special
sensemaking features in a controlled laboratory study. We found that the
sensemaking translucence interface significantly improved clue finding and
crime solving performance, but that analysts rated the interface lower on
subjective measures than the standard interface. We conclude that designing for
distributed sensemaking requires balancing task performance vs. user experience
and real-time information sharing vs. data accuracy.Comment: ACM SIGCHI CSCW 201
Beyond Binomial and Negative Binomial: Adaptation in Bernoulli Parameter Estimation
Estimating the parameter of a Bernoulli process arises in many applications,
including photon-efficient active imaging where each illumination period is
regarded as a single Bernoulli trial. Motivated by acquisition efficiency when
multiple Bernoulli processes are of interest, we formulate the allocation of
trials under a constraint on the mean as an optimal resource allocation
problem. An oracle-aided trial allocation demonstrates that there can be a
significant advantage from varying the allocation for different processes and
inspires a simple trial allocation gain quantity. Motivated by realizing this
gain without an oracle, we present a trellis-based framework for representing
and optimizing stopping rules. Considering the convenient case of Beta priors,
three implementable stopping rules with similar performances are explored, and
the simplest of these is shown to asymptotically achieve the oracle-aided trial
allocation. These approaches are further extended to estimating functions of a
Bernoulli parameter. In simulations inspired by realistic active imaging
scenarios, we demonstrate significant mean-squared error improvements: up to
4.36 dB for the estimation of p and up to 1.80 dB for the estimation of log p.Comment: 13 pages, 16 figure
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