9,896 research outputs found

    Individual differences and cognitive load

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    Effects of Visual, Seat, and Platform Motion During Flight Simulator Air Transport Pilot Training and Evaluation

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    Access to affordable and effective flight-simulation training devices (FSTDs) is critical to safely train airline crews in aviating, navigating, communicating, making decisions, and managing flightdeck and crew resources. This paper provides an overview of the Federal Aviation Administration- Volpe Center Flight Simulator Human Factors Program examining the requirements for the qualification and use of FSTDs. We will summarize past research investigating the need for a full hexapod-platform motion system, describe regulatory and industry developments, and report on current activities

    Noisy Monte Carlo: Convergence of Markov chains with approximate transition kernels

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    Monte Carlo algorithms often aim to draw from a distribution π\pi by simulating a Markov chain with transition kernel PP such that π\pi is invariant under PP. However, there are many situations for which it is impractical or impossible to draw from the transition kernel PP. For instance, this is the case with massive datasets, where is it prohibitively expensive to calculate the likelihood and is also the case for intractable likelihood models arising from, for example, Gibbs random fields, such as those found in spatial statistics and network analysis. A natural approach in these cases is to replace PP by an approximation P^\hat{P}. Using theory from the stability of Markov chains we explore a variety of situations where it is possible to quantify how 'close' the chain given by the transition kernel P^\hat{P} is to the chain given by PP. We apply these results to several examples from spatial statistics and network analysis.Comment: This version: results extended to non-uniformly ergodic Markov chain

    Magnetic Fourier Integral Operators

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    In some previous papers we have defined and studied a 'magnetic' pseudodifferential calculus as a gauge covariant generalization of the Weyl calculus when a magnetic field is present. In this paper we extend the standard Fourier Integral Operators Theory to the case with a magnetic field, proving composition theorems, continuity theorems in 'magnetic' Sobolev spaces and Egorov type theorems. The main application is the representation of the evolution group generated by a 1-st order 'magnetic' pseudodifferential operator (in particular the relativistic Schr\"{o}dinger operator with magnetic field) as such a 'magnetic' Fourier Integral Operator. As a consequence of this representation we obtain some estimations for the distribution kernel of this evolution group and a result on the propagation of singularities

    Geometric Path Integrals. A Language for Multiscale Biology and Systems Robustness

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    In this paper we suggest that, under suitable conditions, supervised learning can provide the basis to formulate at the microscopic level quantitative questions on the phenotype structure of multicellular organisms. The problem of explaining the robustness of the phenotype structure is rephrased as a real geometrical problem on a fixed domain. We further suggest a generalization of path integrals that reduces the problem of deciding whether a given molecular network can generate specific phenotypes to a numerical property of a robustness function with complex output, for which we give heuristic justification. Finally, we use our formalism to interpret a pointedly quantitative developmental biology problem on the allowed number of pairs of legs in centipedes

    On the flexibility of the design of Multiple Try Metropolis schemes

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    The Multiple Try Metropolis (MTM) method is a generalization of the classical Metropolis-Hastings algorithm in which the next state of the chain is chosen among a set of samples, according to normalized weights. In the literature, several extensions have been proposed. In this work, we show and remark upon the flexibility of the design of MTM-type methods, fulfilling the detailed balance condition. We discuss several possibilities and show different numerical results

    Flipped gaming-testing three simulation games

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    © 2018 IEEE. At the Inland Norway University of Applied Sciences 'flipped gaming' has been tested with two student groups (in 2017). This paper will present a newer version of the 'flipping' and also how a total of eight groups utilized tree different types of simulators to play the scenarios. The scenarios were developed by the student themselves as this was their mandatory assignment. The mandatory assignment was handed out in January. The assignment was about making a playable script for an incident, in addition to conduct the planning, execution and evaluation of a complete exercise in crisis management. They were given feedback once before the workshop where they presented and played the script. The tools that were used was Rayvn (https://rayvn.global/), Microsoft HoloLens (https://www.microsoft.com/nb-no/hololens) and a simulator based on a platform from Bohemia Interactive Solutions (https://bisimulations.com/)-the same platform as Virtual Battle Space 3 uses. Rayvn is an incident management tool, mainly for communication. The written messages can then be logged and stored for later reflections. Microsoft HoloLens is a tool for 3D vision, a tool that can show environments in 3D and allow the player to carry out operations using movements that are recorded and executed. This was a prototype. The game based simulator is computer based. The different views are 2D maps and 3D environments. The players use the keyboard and mouse to move the vehicles and avatars around. This in a 'disaster town', called 'Lyngvik', a very poor planned city centre with a large accident/crisis potential. The study is based on the previous study of the learning outcome from assignment that is based on student input. The mandatory assignment was to develop a playable scenario and they could choose in which of the three different simulation tools they were to play their scenario. Two by two, the groups are to play each other's scenario. They have received some supervision and the lecturers have remarked on that the students may lack insight in what a 'playable scenario' require. One of the groups operates as the exercise management staff(the ones that makes the incidents happen and 'play out') and the other group is the ones who man the different roles in handling the scenario e.g.,-different call out services. This group is also calledmain training audience (MTA). The students are in their 6th and last semester in their Bachelor in Crisis Management. The students have been subjected to diverse teaching methods, but this is the first time they have a simulation tool to work with in order to enhance their learning outcome. The preliminary reports from the reflections after the simulating are very positive. The students report on a learning outcome, both from making the scenarios and from simulating. There is also a final report to be written where the students are to reflect on their learning outcome from the simulation and the work on the assignment. The paper shows the results from the whole undertaking and presents further details from the different phases. We also present the theoretical backdrop and the methodological reasoning behind the data collection and analysis

    Induction of annexin-1 at transcriptional and post-transcriptional level in rat brain by methylprednisolone and the 21-aminosteroid U74389F

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    Brain tissue of rats pretreated with methylprednisolone or with the 21-aminosteroid U74389F, and that of untreated control rats, was assessed for the expression of annexin-1 (Anx-1) and the transcription of its mRNA. For this purpose Anx-1 cDNA was amplified and simultaneously a T7-RNA-polymerase promoter was incorporated into the cDNA using a polymerase chain reaction (PCR). Then digoxigenin-11-UTP was incorporated into the transcribed cRNA with T7-RNA-polymerase. With this probe in situ hybridization was carried out on sections of the brain. The probe was visualized by an immunoassay using an antidigoxigenin antibody conjugate. Anx-1 protein was assessed by means of immunohistochemistry using a polyclonal antibody. The various brain areas of the control animals showed an appreciable amount of Anx-1 at mRNA or protein level; on the other hand, the animals which had been pretreated with either steroid, showed a more intense Anx-1 mRNA signal than the controls in many areas. In the pretreated animals Anx-1 immunostaining was unchanged in cortex, basal ganglia, amygdala and septum, but more intense in hippocampus, hypothalamus and thalamus. In ependyma, choroid plexus, meninges, and vascular walls there was no Anx-1 mRNA transcription detectable. An opposite profile was shown by the Anx-1 immunoreactivity, the protein was present in control animals as well as the steroid-pretreated animals, suggesting that here the protein was either from systemic origin, or has diffused from adjacent structures. The results indicated that Anx-1 mRNA transcription is upregulated by either steroid, and that in the untreated animals there is a resting level of Anx-1 mRNA transcription, presumably reflecting physiological influences on Anx-1 expression

    Unstable particles as open quantum systems

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    We present the probability preserving description of the decaying particle within the framework of quantum mechanics of open systems taking into account the superselection rule prohibiting the superposition of the particle and vacuum. In our approach the evolution of the system is given by a family of completely positive trace preserving maps forming one-parameter dynamical semigroup. We give the Kraus representation for the general evolution of such systems which allows one to write the evolution for systems with two or more particles. Moreover, we show that the decay of the particle can be regarded as a Markov process by finding explicitly the master equation in the Lindblad form. We also show that there are remarkable restrictions on the possible strength of decoherence.Comment: 11 pp, 2 figs (published version
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