593 research outputs found

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    Integration von Panorama-Bilddaten in eine Echtzeit-Game Engine für Virtual Reality Szenen

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    Für die prototypische Erstellung von Virtual Reality (VR) Szenen auf Grundlage realer Umgebungen bieten sich Daten aus aktuellen Panorama-Kameras an. Diese Daten eignen sich jedoch nicht unmittelbar für die Integration in eine Game Engine. Wir stellen daher ein projektionsbasiertes Verfahren vor, mit dem Bilder und Videos im Fischaugenformat, wie sie z.B. die 360 Kamera Ricoh Theta erstellt, ohne Konvertierung in Echtzeit mit Hilfe der Unity Game Engine visualisiert werden können. Es wird weiterhin gezeigt, dass ein Panoramabild mit diesem Verfahren leicht manuell um grobe Tiefeninformation erweitert werden kann, sodass bei einer Darstellung in VR ein grober räumlicher Eindruck der Szene für einfach prototypische Umsetzungen ermöglicht wird

    Here's Looking At You Anyway!: How Important is Realistic Gaze Behavior in Co-located Social Virtual Reality Games?

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    Simulating eye movements for virtual humans or avatars can improve social experiences in virtual reality (VR) games, especially when wearing head mounted displays. While other researchers have already demonstrated the importance of simulating meaningful eye movements, we compare three gaze models with different levels of fidelity regarding realism: (1) a base model with static fixation and saccadic movements, (2) a proposed simulation model that extends the saccadic model with gaze shifts based on a neural network, and (3) a user's real eye movements recorded by a proprietary eye tracker. Our between-groups design study with 42 subjects evaluates impact of eye movements on social VR user experience regarding perceived quality of communication and presence. The tasks include free conversation and two guessing games in a co-located setting. Results indicate that a high quality of communication in co-located VR can be achieved without using extended gaze behavior models besides saccadic simulation. Users might have to gain more experience with VR technology before being able to notice subtle details in gaze animation. In the future, remote VR collaboration involving different tasks requires further investigation

    Comparison of Two Inventory Design Concepts in a Collaborative Virtual Reality Serious Game

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    Inventory design in games is crucial when it comes to managing in-game items efficiently. In multi-user settings, an additional goal is to support awareness concerning a coplayer’s inventory and his/her available actions. Especially in virtual reality (VR), presence and immersion are vital aspects of the experience, suggesting real-world metaphors for interface design. The presented work examines two basic inventory paradigms: an abstract menu-based inventory and a metaphoric virtual belt. Both systems are implemented in a serious game prototype for paramedic training in VR, then evaluated in a between-group design study with paramedic trainees inexperienced in VR technology. While both solutions offer comparable usability and presence scores, the results suggest future optimization

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    Applying Multi-User Virtual Reality to Collaborative Medical Training

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    We present a multi-user virtual reality (VR) setup that aims at providing novel training tools for paramedics that enhances current learning methods. The hardware setup consists of a two-user full-scale VR environment with head-mounted displays for two interactive trainees and one additional desktop pc for one trainer participant. The software provides a connected multi-user environment, showcasing a paramedic emergency simulation with focus on anaphylactic shock, a representative scenario for critical medical cases that happen too rare to eventually occur within a regular curricular term of vocational training. The prototype offers hands-on experience on multi-user VR in an applied scenario, generating discussion around current state and future development concerning three important research areas: (a) user navigation, (b) interaction, (c) level of visual abstraction, and (d) level of task abstraction

    Applying Multi-User Virtual Reality to Collaborative Medical Training

    No full text
    We present a multi-user virtual reality (VR) setup that aims at providing novel training tools for paramedics that enhances current learning methods. The hardware setup consists of a two-user full-scale VR environment with head-mounted displays for two interactive trainees and one additional desktop pc for one trainer participant. The software provides a connected multi-user environment, showcasing a paramedic emergency simulation with focus on anaphylactic shock, a representative scenario for critical medical cases that happen too rare to eventually occur within a regular curricular term of vocational training. The prototype offers hands-on experience on multi-user VR in an applied scenario, generating discussion around current state and future development concerning three important research areas: (a) user navigation, (b) interaction, (c) level of visual abstraction, and (d) level of task abstraction

    Multiplicity dependence of light (anti-)nuclei production in p–Pb collisions at sNN=5.02 TeV

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    The measurement of the deuteron and anti-deuteron production in the rapidity range −1 < y < 0 as a function of transverse momentum and event multiplicity in p–Pb collisions at √sNN = 5.02 TeV is presented. (Anti-)deuterons are identified via their specific energy loss dE/dx and via their time-of- flight. Their production in p–Pb collisions is compared to pp and Pb–Pb collisions and is discussed within the context of thermal and coalescence models. The ratio of integrated yields of deuterons to protons (d/p) shows a significant increase as a function of the charged-particle multiplicity of the event starting from values similar to those observed in pp collisions at low multiplicities and approaching those observed in Pb–Pb collisions at high multiplicities. The mean transverse particle momenta are extracted from the deuteron spectra and the values are similar to those obtained for p and particles. Thus, deuteron spectra do not follow mass ordering. This behaviour is in contrast to the trend observed for non-composite particles in p–Pb collisions. In addition, the production of the rare 3He and 3He nuclei has been studied. The spectrum corresponding to all non-single diffractive p-Pb collisions is obtained in the rapidity window −1 < y < 0 and the pT-integrated yield dN/dy is extracted. It is found that the yields of protons, deuterons, and 3He, normalised by the spin degeneracy factor, follow an exponential decrease with mass number
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