55,204 research outputs found

    Psychological effects of music tempi during exercise

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    The purpose of this study was to investigate the effects of music tempi on intrinsic motivation, flow, and music tempo preference during longduration exercise (~ 26 min). Subjects (n = 29) selected the music of a single artist then walked at 70% of maximum heart rate reserve (maxHRR) on a treadmill under three experimental conditions (medium tempi, fast tempi, and mixed tempi) and a no-music control. A tempo preference item, the Intrinsic Motivation Inventory, and Flow State Scale-2 were completed after each trial. Data were analyzed using a mixed-model (Gender × Condition) ANOVA and MANOVA. The Gender × Condition interaction was nonsignificant in both analyses (p > 0.05). Contrary to expectations, higher preference scores were recorded for medium tempi than for mixed tempi (means: 7.8 ± 1.3 vs. 7.1 ± 1.1). The medium tempi music also yielded the highest levels of intrinsic motivation (p < 0.001). Pairwise comparisons showed that interest-enjoyment was higher for medium tempi when compared to mixed tempi, 95% CI = 1.80–8.48, p = 0.001, and that each of the experimental conditions yielded higher scores than the no-music control. Also, pressure-tension was lower for medium tempi compared to fast tempi, 95% CI = – 3.44–0.19, p = 0.022, and for both medium and mixed tempi compared to control (95% CI = – 5.33–2.89, p = 0.000; 95% CI = – 4.24–0.64, p = 0.004). A main effect was found for global flow (p = 0.000) with the highest mean score evident in the medium tempi condition (14.6 ± 1.5). Follow-up comparisons indicated that the medium tempi condition yielded higher flow scores than the control, 95% CI = 1.25–3.60, p = .000, as did fast tempi, 95% CI = 0.89–3.14, p = 0.000, and mixed tempi, 95% CI = 1.36–3.76, p = 0.000. It was concluded that a medium tempi music program was the most appropriate for an exercise intensity of 70%maxHRR

    The Professional Identity of SALL Practitioners

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    Session: Facilitating self-access learningThe article can be viewed at: http://sola.kmutt.ac.th/dral2014/proceedings_online/106-114%20ILA%20David%20Gardner%20Lindsay%20Miller-formatted.pdfThis paper examines the professional identity of practitioners in the field of self-access language learning (SALL) at tertiary level institutions in Hong Kong. It uses research data and examples from the literature to illustrate membership of a SALL practitioners’ professional community which exhibits the characteristics of a “community of practice” (CoP) as defined by Lave and Wenger (1991). After outlining the three key elements (Wenger, 2006) and the seven main principles of a CoP (Wenger et al, 2003), we illustrate through interview data a clear example of membership and non-membership of the community and discuss an example of how teachers who are not initially members were inducted into a CoP by challenging their beliefs and values. Thirdly, we identify ways to bring teachers into a SALL practitioners’ CoP and review the key features which promote and strengthen such a community. Nurturing a strong SALL practitioner’s CoP and encouraging teachers’ membership of it contributes to the development of their professional identity

    Left main bronchus compression due to main pulmonary artery dilatation in pulmonary hypertension: two case reports

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    Abstract. Pulmonary arterial dilatation associated with pulmonary hypertension may result in significant compression of local structures. Left main coronary artery and left recurrent laryngeal nerve compression have been described. Tracheobronchial compression from pulmonary arterial dilatation is rare in adults, and there are no reports in the literature of its occurrence in idiopathic pulmonary arterial hypertension. Compression in infants with congenital heart disease has been well described. We report 2 cases of tracheobronchial compression: first, an adult patient with idiopathic pulmonary arterial hypertension who presents with symptomatic left main bronchus compression, and second, an adult patient with Eisenmenger ventricular septal defect and right-sided aortic arch, with progressive intermedius and right middle lobe bronchi compression in association with enlarged pulmonary arteries

    CAPTCHaStar! A novel CAPTCHA based on interactive shape discovery

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    Over the last years, most websites on which users can register (e.g., email providers and social networks) adopted CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart) as a countermeasure against automated attacks. The battle of wits between designers and attackers of CAPTCHAs led to current ones being annoying and hard to solve for users, while still being vulnerable to automated attacks. In this paper, we propose CAPTCHaStar, a new image-based CAPTCHA that relies on user interaction. This novel CAPTCHA leverages the innate human ability to recognize shapes in a confused environment. We assess the effectiveness of our proposal for the two key aspects for CAPTCHAs, i.e., usability, and resiliency to automated attacks. In particular, we evaluated the usability, carrying out a thorough user study, and we tested the resiliency of our proposal against several types of automated attacks: traditional ones; designed ad-hoc for our proposal; and based on machine learning. Compared to the state of the art, our proposal is more user friendly (e.g., only some 35% of the users prefer current solutions, such as text-based CAPTCHAs) and more resilient to automated attacks.Comment: 15 page

    Measuring situation awareness in complex systems: Comparison of measures study

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    Situation Awareness (SA) is a distinct critical commodity for teams working in complex industrial systems and its measurement is a key provision in system, procedural and training design efforts. This article describes a study that was undertaken in order to compare three different SA measures (a freeze probe recall approach, a post trial subjective rating approach and a critical incident interview technique) when used to assess participant SA during a military planning task. The results indicate that only the freeze probe recall method produced a statistically significant correlation with performance on the planning task and also that there was no significant correlation between the three methods, which suggests that they were effectively measuring different things during the trials. In conclusion, the findings, whilst raising doubts over the validity of post trial subjective rating and interview-based approaches, offer validation evidence for the use of freeze probe recall approaches to measure SA. The findings are subsequently discussed with regard to their implications for the future measurement of SA in complex collaborative systems

    Compressing Word Embeddings

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    Recent methods for learning vector space representations of words have succeeded in capturing fine-grained semantic and syntactic regularities using vector arithmetic. However, these vector space representations (created through large-scale text analysis) are typically stored verbatim, since their internal structure is opaque. Using word-analogy tests to monitor the level of detail stored in compressed re-representations of the same vector space, the trade-offs between the reduction in memory usage and expressiveness are investigated. A simple scheme is outlined that can reduce the memory footprint of a state-of-the-art embedding by a factor of 10, with only minimal impact on performance. Then, using the same `bit budget', a binary (approximate) factorisation of the same space is also explored, with the aim of creating an equivalent representation with better interpretability.Comment: 10 pages, 0 figures, submitted to ICONIP-2016. Previous experimental results were submitted to ICLR-2016, but the paper has been significantly updated, since a new experimental set-up worked much bette

    The thermal expansion of (Fe1-y Ni y )Si

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    We have measured the thermal expansion of (Fe1-y Ni y )Si for y  =  0, 0.1 and 0.2, between 40 and 1273 K. Above ~700 K the unit-cell volumes of the samples decrease approximately linearly with increasing Ni content. Below ~200 K the unit-cell volume of FeSi falls to a value between that of (Fe0.9Ni0.1)Si and (Fe0.8Ni0.2)Si. We attribute this extra contraction of the FeSi, which is a narrow band-gap semiconductor, to the depopulation of the conduction band at low temperatures; in the two alloys the additional electrons introduced by the substitution of Ni lead to the conduction band always being populated. We have fit the unit-cell volume data with a Debye internal energy model of thermal expansion and an additional volume term, above 800 K, to take account of the volumetric changes associated with changes in the composition of the sample. Using the thermophysical parameters of the fit we have estimated the band gap in FeSi to be 21(1) meV and the unit-cell volume change in FeSi associated with the depopulation of the conduction band to be 0.066(35) Å(3)/unit-cell

    Ectoplasm with an Edge

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    The construction of supersymmetric invariant actions on a spacetime manifold with a boundary is carried out using the "ectoplasm" formalism for the construction of closed forms in superspace. Non-trivial actions are obtained from the pull-backs to the bosonic bodies of closed but non-exact forms in superspace; finding supersymmetric invariants thus becomes a cohomology problem. For a spacetime with a boundary, the appropriate mathematical language changes to relative cohomology, which we use to give a general formulation of off-shell supersymmetric invariants in the presence of boundaries. We also relate this construction to the superembedding formalism for the construction of brane actions, and we give examples with bulk spacetimes of dimension 3, 4 and 5. The closed superform in the 5D example needs to be constructed as a Chern-Simons type of invariant, obtained from a closed 6-form displaying Weil triviality.Comment: 25 page

    Privacy-Preserving Outsourcing of Large-Scale Nonlinear Programming to the Cloud

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    The increasing massive data generated by various sources has given birth to big data analytics. Solving large-scale nonlinear programming problems (NLPs) is one important big data analytics task that has applications in many domains such as transport and logistics. However, NLPs are usually too computationally expensive for resource-constrained users. Fortunately, cloud computing provides an alternative and economical service for resource-constrained users to outsource their computation tasks to the cloud. However, one major concern with outsourcing NLPs is the leakage of user's private information contained in NLP formulations and results. Although much work has been done on privacy-preserving outsourcing of computation tasks, little attention has been paid to NLPs. In this paper, we for the first time investigate secure outsourcing of general large-scale NLPs with nonlinear constraints. A secure and efficient transformation scheme at the user side is proposed to protect user's private information; at the cloud side, generalized reduced gradient method is applied to effectively solve the transformed large-scale NLPs. The proposed protocol is implemented on a cloud computing testbed. Experimental evaluations demonstrate that significant time can be saved for users and the proposed mechanism has the potential for practical use.Comment: Ang Li and Wei Du equally contributed to this work. This work was done when Wei Du was at the University of Arkansas. 2018 EAI International Conference on Security and Privacy in Communication Networks (SecureComm
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