64,423 research outputs found
Non-visual information display using tactons
This paper describes a novel form of display using tactile output. Tactons, or tactile icons, are structured tactile messages that can be used to communicate message to users non visually. A range of different parameters can be used to construct Tactons, e.g.: frequency, amplitude, waveform and duration of a tactile pulse, plus body location. Tactons have the potential to improve interaction in a range of different areas, particularly where the visual display is overloaded, limited in size or not available, such as interfaces for blind people or on mobile and wearable devices
Investigation into the impact of integral suppressor configurations on the pressure levels within the suppressor
This paper reports on an experimental investigation supported by basic modeling in to the performance of an integral suppressor on a low power firearm. A model was developed to determine the pressure within a suppressor chamber using iterative empirical calculations of the gas properties and flow within the system. The design of a reconfigurable suppressor chamber has been undertaken allowing suppressor chamber volume to be varied through the use of baffles. Pressure transducers were used to determine the pressure within the suppressor chamber for a series of firings. The results of the firings with different configurations within the suppressor are presented allowing trends to be established. The modeling and experimental results show an increase in suppressor chamber volume results in a reduction of recorded pressure within the suppressor chamber
Beyond Landauer erasure
In thermodynamics one considers thermal systems and the maximization of
entropy subject to the conservation of energy. A consequence is Landauer's
erasure principle, which states that the erasure of 1 bit of information
requires a minimum energy cost equal to where is the temperature
of a thermal reservoir used in the process and is Boltzmann's constant.
Jaynes, however, argued that the maximum entropy principle could be applied to
any number of conserved quantities which would suggest that information erasure
may have alternative costs. Indeed we showed recently that by using a reservoir
comprising energy degenerate spins and subject to conservation of angular
momentum, the cost of information erasure is in terms of angular momentum
rather than energy. Here we extend this analysis and derive the minimum cost of
information erasure for systems where different conservation laws operate. We
find that, for each conserved quantity, the minimum resource needed to erase 1
bit of memory is where is related to the average
value of the conserved quantity. The costs of erasure depend, fundamentally, on
both the nature of the physical memory element and the reservoir with which it
is coupled.Comment: 7 pages, 3 figure
Measurement of tan beta in associated t H^\pm Production in gamma gamma Collisions
The ratio of neutral Higgs field vacuum expectation values, tan beta, is one
of the most important parameters to determine in type-II Two-Higgs Doublet
Models (2HDM), specifically the Minimal Supersymmetric Standard Model (MSSM).
Assuming the energies and integrated luminosity of a future high energy e^+e^-
linear collider of sqrt{s}=500, 800, 1000, and 1500 GeV and L=1 ab^{-1} we show
that associated t H^+/- production in gamma gamma collisions can be used to
make an accurate determination of tan beta for low and high tan beta by
precision measurements of the gamma gamma -> H^+/- t + X cross section.Comment: 7 pages, 11 figures, uses REVTEX
Shift in the LHC Higgs diphoton mass peak from interference with background
The Higgs diphoton amplitude from gluon fusion at the LHC interferes with the
continuum background induced by quark loops. I investigate the effect of this
interference on the position of the diphoton invariant mass peak used to help
determine the Higgs mass. At leading order, the interference shifts the peak
towards lower mass by an amount of order 150 MeV or more, with the precise
value dependent on the methods used to analyze and fit the data.Comment: 10 pages. v2: comments on scale variation added, reference adde
Is coherence catalytic?
Quantum coherence, the ability to control the phases in superposition states
is a resource, and it is of crucial importance, therefore, to understand how it
is consumed in use. It has been suggested that catalytic coherence is possible,
that is repeated use of the coherence without degradation or reduction in
performance. The claim has particular relevance for quantum thermodynamics
because, were it true, it would allow free energy that is locked in coherence
to be extracted . We address this issue directly with a
careful analysis of the proposal by berg. We find that coherence
be used catalytically, or even repeatedly without limit.Comment: 23 pages with 2 figure
The role of memory and restricted context in repeated visual search
Previous studies have shown that the efficiency of visual search does not improve when participants search
through the same unchanging display for hundreds of trials (repeated search), even though the participants have
a clear memory of the search display. In this article, we ask two important questions. First, why do participants
not use memory to help search the repeated display? Second, can context be introduced so that participants are
able to guide their attention to the relevant repeated items? Experiments 1–4 show that participants choose not
to use a memory strategy because, under these conditions, repeated memory search is actually less efficient than
repeated visual search, even though the latter task is in itself relatively inefficient. However, when the visual
search task is given context, so that only a subset of the items are ever pertinent, participants can learn to restrict
their attention to the relevant stimuli (Experiments 5 and 6)
Two-loop scalar self-energies and pole masses in a general renormalizable theory with massless gauge bosons
I present the two-loop self-energy functions for scalar bosons in a general
renormalizable theory, within the approximation that vector bosons are treated
as massless or equivalently that gauge symmetries are unbroken. This enables
the computation of the two-loop physical pole masses of scalar particles in
that approximation. The calculations are done simultaneously in the
mass-independent \bar{MS}, \bar{DR}, and \bar{DR}' renormalization schemes, and
with arbitrary covariant gauge fixing. As an example, I present the two-loop
SUSYQCD corrections to squark masses, which can increase the known one-loop
results by of order one percent. More generally, it is now straightforward to
implement all two-loop sfermion pole mass computations in supersymmetry using
the results given here, neglecting only the electroweak vector boson masses
compared to the superpartner masses in the two-loop parts.Comment: 16 pages, 4 figures. v2: typo in eq. (5.30) fixe
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