55,204 research outputs found
Psychological effects of music tempi during exercise
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
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
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
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
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
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
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Psychometric properties of the Stroke and Aphasia Quality of Life Scale (SAQOL-39) in a generic stroke population
Background: We previously developed the Stroke and Aphasia Quality of Life scale (SAQOL-39) and tested it with people with chronic aphasia. A scale allowing comparisons of quality of life between people with versus without aphasia post-stroke would be of value to clinicians.
Objectives: To evaluate the psychometrics of the SAQOL-39 in a generic stroke sample. Should this process result in a generic-stroke version of the scale (SAQOL-39g), a further aim is to compare the latter and the SAQOL-39 as tested in chronic aphasia.
Design and subjects: Repeated measures psychometric study, evaluating internal consistency, test—retest reliability, construct validity and responsiveness to change. People admitted to hospital with a first stroke were assessed two weeks, three months and six months post stroke.
Measures: SAQOL-39, National Institutes of Health Stroke Scale, Barthel, Frenchay Aphasia Screening Test, General Health Questionnaire-12 and Frenchay Activities Index.
Results: Of 126 eligible participants, 96 (76%) participated and 87 (69%) were able to self-report and are presented here. Testing the SAQOL-39 in generic stroke resulted in the SAQOL-39g, which has the same items as the SAQOL-39 but three domains: physical, psychosocial, communication. The SAQOL-39g showed good internal consistency (α = 0.95 overall score, 0.92—0.95 domains), test—retest reliability (interclass correlation (ICC) = 0.96 overall, 0.92—0.98 domains), convergent (r = 0.36—0.70 overall, 0.47—0.78 domains) and discriminant validity (r = 0.26 overall, 0.03—0.40 domains). It differentiated people by stroke severity and visual analogue scale (VAS)-defined quality of life. Moderate changes (d = 0.35—0.49; standardized response mean (SRM) = 0.29—0.53) from two weeks to six months supported responsiveness.
Conclusions: The SAQOL-39g demonstrated good reliability, validity and responsiveness to change. It can be used to evaluate quality of life in people with and without aphasia post stroke
The thermal expansion of (Fe1-y Ni y )Si
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
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
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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