746 research outputs found
Assessment of Psychophysiological Differences of West Point Cadets and Civilian Controls Immersed within a Virtual Environment
Abstract. An important question for ecologically valid virtual environments is whether cohort characteristics affect immersion. If a method for assessing a cer-tain neurocognitive capacity (e.g. attentional processing) is adapted to a cohort other than the one that was used for the initial normative distribution, data ob-tained in the new cohort may not be reflective of the neurocognitive capacity in question. We assessed the psychophysiological impact of different levels of immersion upon persons from two cohorts: 1) civilian university students; and 2) West Point Cadets. Cadets were found to have diminished startle eyeblink amplitude compared with civilians, which may reflect that cadets experienced less negative affect during the scenario in general. Further, heart rate data re-vealed that Cadets had significantly lower heart rates than Civilians in the “low ” but not “high ” immersion condition. This suggests that “low ” immersion conditions may not have the ecological validity necessary to evoke consistent affect across cohorts
Settling on the group's goals: An n-person argumentation game approach
Argumentation games have been proved to be a robust and flexible tool to resolve conflicts among agents. An agent can propose its explanation and its goal known as a claim, which can be refuted by other agents. The situation is more complicated when there are more than two agents playing the game. We propose a weighting mechanism for competing premises to tackle with conflicts from multiple agents in an n-person game. An agent can defend its proposal by giving a counter-argument to change the ``opinion'' of the majority of opposing agents. During the game, an agent can exploit the knowledge that other agents expose in order to promote and defend its main claim
Inflation and the Scale Dependent Spectral Index: Prospects and Strategies
We consider the running of the spectral index as a probe of both inflation
itself, and of the overall evolution of the very early universe. Surveying a
collection of simple single field inflationary models, we confirm that the
magnitude of the running is relatively consistent, unlike the tensor amplitude,
which varies by orders of magnitude. Given this target, we confirm that the
running is potentially detectable by future large scale structure or 21 cm
observations, but that only the most futuristic measurements can distinguish
between these models on the basis of their running. For any specified
inflationary scenario, the combination of the running index and unknown
post-inflationary expansion history induces a theoretical uncertainty in the
predicted value of the spectral index. This effect can easily dominate the
statistical uncertainty with which Planck and its successors are expected to
measure the spectral index. More positively, upcoming cosmological experiments
thus provide an intriguing probe of physics between TeV and GUT scales by
constraining the reheating history associated with any specified inflationary
model, opening a window into the "primordial dark age" that follows the end of
inflation.Comment: 32 pages. v2 and v3 Minor reference updates /clarification
Applications of scalar attractor solutions to Cosmology
We develop a framework to study the phase space of a system consisting of a
scalar field rolling down an arbitrary potential with varying slope and a
background fluid, in a cosmological setting. We give analytical approximate
solutions of the field evolution and discuss applications of its features to
the issues of quintessence, moduli stabilisation and quintessential inflation.Comment: 9 pages, 7 figures. Accepted for publication in PR
A Coalescing Filter for Liquid–Liquid Separation and Multistage Extraction in Continuous-Flow Chemistry
Presented here is the design and performance of a coalescing liquid–liquid filter, based on low-cost and readily available meltblown nonwoven substrates for separation of immiscible phases. The performance of the coalescer was determined across three broad classes of fluid mixtures: (i) immiscible organic/aqueous systems, (ii) a surfactant laden organic/aqueous system with modification of the type of emulsion and interfacial surface tension through the addition of sodium chloride, and (iii) a water–acetone/toluene system. The first two classes demonstrated good performance of the equipment in effecting separation, including the separation of a complex emulsion system for which a membrane separator, operating through transport of a preferentially wetting fluid through the membrane, failed entirely. The third system was used to demonstrate the performance of the separator within a multistage liquid–liquid counterflow extraction system. The performance, robust nature, and scalability of coalescing filters should mean that this approach is routinely considered for liquid–liquid separations and extractions within the fine chemical and pharmaceutical industry
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The value in de-emphasizing structure in liquidity
In the set of commentaries on liquidity entitled “The continuing significance of social structure in liquid modernity,” three sets of authors set out to examine the relationship between liquidity and structure, value, and distinction. In doing so, they attempt to marry theories which argue against sociologist Zygmunt Bauman’s central thesis that societal structures are shifting with his seminal construct of liquidity, an exercise that has mixed results. All three sets of authors have engaged with Bauman’s conceptualization of liquid modernity as well as our conceptualization of liquid consumption and its consequences. In this response to the commentaries, we clarify how we understand Bauman and how we have used his ideas in our theorizing, engage with the three sets of author’s advocacy for emphasizing the continuing relevance of structure within liquidity, and, finally, sum up how de-emphasizing structure has and can continue to lead to important new insights in marketing theory
Inflation at Low Scales: General Analysis and a Detailed Model
Models of inflationary cosmology based on spontaneous symmetry breaking
typically suffer from the shortcoming that the symmetry breaking scale is
driven to nearly the Planck scale by observational constraints. In this paper
we investigate inflationary potentials in a general context, and show that this
difficulty is characteristic only of potentials dominated near their
maxima by terms of order . We find that potentials dominated by terms
of order with \hbox{} can satisfy observational constraints at
an arbitrary symmetry breaking scale. Of particular interest, the spectral
index of density fluctuations is shown to depend only on the order of the
lowest non-vanishing derivative of near the maximum. This result is
illustrated in the context of a specific model, with a broken
symmetry, in which the potential is generated by gauge boson loops.Comment: Submitted to Phys. Rev. D. 32 Pages, REVTeX. No figure
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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