Oscillograms and their tests

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Modelling the preferences of students for alternative assignment designs using the Discrete Choice Experiment methodology

This paper outlines how a discrete choice experiment (DCE) can be used to learn more about how students are willing to trade off various features of assignments such as the nature and timing of feedback and the method used to submit assignments. A DCE identifies plausible levels of the key attributes of a good or service and then presents the respondent with alternative bundles of these attributes and their levels and asks the respondent to choose between particular bundles. We report results from a DCE we conducted with undergraduate business students regarding their preferences for assignment systems. We find that the most important features of assignments are how relevant the assignments are for exam preparation and the nature of the feedback that students receive. We also find that students generally prefer online to paper assignments. We argue that the DCE approach has a lot of potential in education research. Accessed 4,497 times on https://pareonline.net from November 13, 2014 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Multidimensional analogs of geometric s<-->t duality

The usual propetry of st duality for scattering amplitudes, e.g. for Veneziano amplitude, is deeply connected with the 2-dimensional geometry. In particular, a simple geometric construction of such amplitudes was proposed in a joint work by this author and S.Saito (solv-int/9812016). Here we propose analogs of one of those amplitudes associated with multidimensional euclidean spaces, paying most attention to the 3-dimensional case. Our results can be regarded as a variant of "Regge calculus" intimately connected with ideas of the theory of integrable models.Comment: LaTeX2e, pictures using emlines. In this re-submission, an English version of the paper is added (9 pages, file english.tex) to the originally submitted file in Russian (10 pages, russian.tex

Exoplanets or Dynamic Atmospheres? The Radial Velocity and Line Shape Variations of 51 Pegasi and Tau Bootis

Because of our relatively low spectral resolution, we compare our observations with Gray's line bisector data by fitting observed line profiles to an expansion in terms of orthogonal (Hermite) functions. To obtain an accurate comparison, we model the emergent line profiles from rotating and pulsating stars, taking the instrumental point spread function into account. We describe this modeling process in detail. We find no evidence for line profile or strength variations at the radial velocity period in either 51 Peg or in Tau Boo. For 51 Peg, our upper limit for line shape variations with 4.23-day periodicity is small enough to exclude with 10 sigma confidence the bisector curvature signal reported by Gray & Hatzes; the bisector span and relative line depth signals reported by Gray (1997) are also not seen, but in this case with marginal (2 sigma) confidence. We cannot, however, exclude pulsations as the source of 51 Peg's radial velocity variation, because our models imply that line shape variations associated with pulsations should be much smaller than those computed by Gray & Hatzes; these smaller signals are below the detection limits both for Gray & Hatzes' data and for our own. Tau Boo's large radial velocity amplitude and v*sin(i) make it easier to test for pulsations in this star. Again we find no evidence for periodic line-shape changes, at a level that rules out pulsations as the source of the radial velocity variability. We conclude that the planet hypothesis remains the most likely explanation for the existing data.Comment: 44 pages, 19 figures, plain TeX, accepted to ApJS (companion to letter astro-ph/9712279

Line profile analysis of the Delta Scuti star HD2724=BB Phe: mode identification and amplitude variations

The line profile variations of the Delta Scuti star HD 2724=BB Phe were studied on the basis of new 189 high-resolution spectrograms covering 52 hours of observations on a baseline of 8.3 days. By combining these results with those of a previous campaign 13 pulsation modes were identified: 5 of them are both photometric and spectroscopic, 3 are purely spectroscopic and 5 purely photometric. For the first time it was possible to compare spectroscopic data taken in two different seasons: 6 modes were found to be common to both datasets and furthermore strong amplitude variations of the excited modes were detected. The fit of the line profile variations with a model of non-radial pulsating star allowed us to obtain a reasonable estimate of the inclination of the rotational axis and to propose the l,m typing of the spectroscopic modes. The frequency content resembles that of 4 CVn, a delta Sct star with similar physical parameters.Comment: 7 pages (in A&A style), 5 ps figures (Fig. 4 in colour) Accepted for A&A Main Journa

Genetic-Algorithm-based Light Curve Optimization Applied to Observations of the W UMa star BH Cas

I have developed a procedure utilizing a Genetic-Algorithm-based optimization scheme to fit the observed light curves of an eclipsing binary star with a model produced by the Wilson-Devinney code. The principal advantages of this approach are the global search capability and the objectivity of the final result. Although this method can be more efficient than some other comparably global search techniques, the computational requirements of the code are still considerable. I have applied this fitting procedure to my observations of the W UMa type eclipsing binary BH Cassiopeiae. An analysis of V-band CCD data obtained in 1994/95 from Steward Observatory and U- and B-band photoelectric data obtained in 1996 from McDonald Observatory provided three complete light curves to constrain the fit. In addition, radial velocity curves obtained in 1997 from McDonald Observatory provided a direct measurement of the system mass ratio to restrict the search. The results of the GA-based fit are in excellent agreement with the final orbital solution obtained with the standard differential corrections procedure in the Wilson-Devinney code.Comment: 9 pages, 2 figures, 2 tables, uses emulateapj.st

A Systematic Review of Falls Risk of Frail Patients with Dementia in Hospital: Progress, Challenges, and Recommendations

Naomi Davey,1 Eimear Connolly,1 Paul Mc Elwaine,1,2 Sean P Kennelly1,2 1Department of Age Related Healthcare, Tallaght University Hospital, Dublin, Ireland; 2Department of Medical Gerontology, School of Medicine, Trinity College Dublin, Dublin, IrelandCorrespondence: Naomi Davey, Department of Age-Related Healthcare, Tallaght University Hospital, Dublin, Ireland, Email [email protected]: This review article assesses the effectiveness and limitations of strategies to reduce falls among hospitalized older adults with frailty and dementia. It explores the efficacy of existing fall prevention strategies for a cohort that is acutely susceptible to falls and fall-related consequences. A systematic literature search was conducted across MEDLINE, Embase, CINAHL, and PsycINFO, employing Medical Subject Headings (MeSH) to identify studies on fall prevention strategies in hospitalized older adults with both dementia and frailty published from 2013 to 2023. The initial 643 records were distilled to eight articles, with Structured Interdisciplinary Bedside Rounds (SIBR) emerging as a notable intervention. SIBR demonstrated a reduction in falls by fostering improved interdisciplinary communication and care planning. However, a decline in family engagement during consecutive sessions suggests a need for strategies to sustain familial involvement. The findings advocate for patient-centered interventions that address the cognitive and functional challenges faced by this cohort of older adults. This review advocates for comprehensive and inclusive research in hospital environments to improve fall prevention strategies for frail older adults with dementia.Keywords: fall prevention, frailty, dementia, hospitalized older adults, interdisciplinary collaboration, patient-centered intervention

Correlation between molecular lines and diffuse interstellar bands

Observations are presented of the Diffuse Interstellar Bands (DIB's) at 4726, 4763, and 4789 A and at 5780 and 5797 A together with the ultraviolet lines of CH and CN molecules for stars with different shapes of UV extinction curve. The new results concerning the relationship between different characteristics of the interstellar clouds; molecular lines, blue and yellow DIB's, and UV extinction curves are discussed