3,617 research outputs found

    Perfectionism and competitive anxiety in athletes: Differentiating striving for perfection and negative reactions to imperfection

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    Whereas some researchers have argued that perfectionism in sports is maladaptive because it is related to dysfunctional characteristics Such as higher competitive anxiety, the present article argues that striving for perfection is not maladaptive and is unrelated to competitive anxiety. Four samples of athletes (high school athletes, female soccer players, and two samples of university student athletes) completed measures of perfectionism during competitions and competitive anxiety. Across samples, results show that overall perfectionism was associated with higher cognitive and somatic competitive anxiety. However, when striving for perfection and negative reactions to imperfection were differentiated, only the latter were associated with higher anxiety, whereas striving for perfection was unrelated to anxiety. Moreover, once the influence of negative reactions to imperfection was partialled out, striving for perfection was associated with lower anxiety and higher self-confidence. The present findings suggest that striving for perfection in sports is not maladaptive. On the contrary, athletes who strive for perfection and successfully control their negative reactions to imperfection may even experience less anxiety and more self-confidence during competitions

    Constructing a gazebo: supporting teamwork in a tightly coupled, distributed task in virtual reality

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    Many tasks require teamwork. Team members may work concurrently, but there must be some occasions of coming together. Collaborative virtual environments (CVEs) allow distributed teams to come together across distance to share a task. Studies of CVE systems have tended to focus on the sense of presence or copresence with other people. They have avoided studying close interaction between us-ers, such as the shared manipulation of objects, because CVEs suffer from inherent network delays and often have cumbersome user interfaces. Little is known about the ef-fectiveness of collaboration in tasks requiring various forms of object sharing and, in particular, the concurrent manipu-lation of objects. This paper investigates the effectiveness of supporting teamwork among a geographically distributed group in a task that requires the shared manipulation of objects. To complete the task, users must share objects through con-current manipulation of both the same and distinct at-tributes. The effectiveness of teamwork is measured in terms of time taken to achieve each step, as well as the impression of users. The effect of interface is examined by comparing various combinations of walk-in cubic immersive projection technology (IPT) displays and desktop devices

    Single-crystal NMR spectroscopy – method development and application to inorganic solids

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    A study of event traffic during the shared manipulation of objects within a collaborative virtual environment

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    Event management must balance consistency and responsiveness above the requirements of shared object interaction within a Collaborative Virtual Environment (CVE) system. An understanding of the event traffic during collaborative tasks helps in the design of all aspects of a CVE system. The application, user activity, the display interface, and the network resources, all play a part in determining the characteristics of event management. Linked cubic displays lend themselves well to supporting natural social human communication between remote users. To allow users to communicate naturally and subconsciously, continuous and detailed tracking is necessary. This, however, is hard to balance with the real-time consistency constraints of general shared object interaction. This paper aims to explain these issues through a detailed examination of event traffic produced by a typical CVE, using both immersive and desktop displays, while supporting a variety of collaborative activities. We analyze event traffic during a highly collaborative task requiring various forms of shared object manipulation, including the concurrent manipulation of a shared object. Event sources are categorized and the influence of the form of object sharing as well as the display device interface are detailed. With the presented findings the paper wishes to aid the design of future systems

    A folded-sandwich polarization-entangled two-color photon pair source with large tuning capability for applications in hybrid quantum architectures

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    We demonstrate a two-color entangled pho ton pair source which can be adapted easily to a wide range of wavelengths combinations. A Fresnel rhomb as a geometrical quarter-wave plate and a versatile combination of compensation crystals are key components of the source. Entanglement of two photons at the Cs D1 line (894.3 nm) and at the telecom O-band (1313.1 nm) with a fidelity of F=0.753±0.021F = 0.753 \pm 0.021 is demonstrated and improvements of the setup are discussed

    Measurement of the full excitation spectrum of the 7Li(p,{\gamma}){\alpha}{\alpha} reaction at 441 keV

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    A current challenge for ab initio calculations is systems that contain large continuum contributions such as 8Be. We report on new measurements of radiative decay widths in this nucleus that test recent Green's function Monte Carlo calculations. Traditionally, {\gamma} ray detectors have been utilized to measure the high energy photons from the 7Li(p, {\gamma}){\alpha}{\alpha} reaction. However, due to the complicated response function of these detectors it has not yet been possible to extract the full {\gamma} ray spectrum from this reaction. Here we present an alternative measurement using large area Silicon detectors to detect the two {\alpha} particles, which provides a practically background free spectrum and retains good energy resolution. The resulting spectrum is analyzed using a many-level multi channel R-matrix parametrization. Improved values for the radiative widths are extracted from the R-matrix fit. We find evidence for significant non-resonant continuum contributions and tentative evidence for a broad 0+ resonance at 12 MeV.Comment: Accepted version. Fixed Fig. 5 ordinate label

    On robust cross-validation for nonparametric smoothing

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    Procedures for local-constant smoothing are investigated in a broad variety of data situations with outliers and jumps. Moving window and nearest neighbour versions of mean and median smoothers are considered, as well as double window and linear hybrid smoothers. For the choice of the window width or the number of neighbours the different estimators are combined with each of several cross-validation criteria like least squares, least absolute deviations, and median-cross-validation. It is identified, which method works best in which data scenarios. Although there is not a single overall best robust smoothing procedure, a robust cross-validation criterion, called least trimmed squares-cross-validation, gives good results for most smoothing methods and data situations, with cross-validation based on least absolute deviations being a strong competitor, particularly if there are jumps, but little problems with outliers in the data

    Agglomerationsvorteile in der Wissensgesellschaft: Empirische Evidenz fĂĽr deutsche Gemeinden

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    Sind Ansammlungen von hochqualifizierten Arbeitskräften in einer Region ein Garant für Wachstum? Eine Politik zur Förderung regionaler Entwicklung unterstellt oftmals diesen Zusammenhang und fördert die Ansiedlung und Vernetzung wissensintensiver Branchen und Unternehmen. Die hier gezeigte empirische Evidenz legt allerdings nahe, dass solche Agglomerationsvorteile nicht überall wirken. Der Erfolg einer solchen Cluster- und Netzwerkpolitik hängt maßgeblich von der Wirkungskraft der regionalen Agglomerationskräfte ab und ist somit nicht garantiert
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