“Tell me what I should watch”: A customer value perspective of YouTube metadata

YouTube is increasingly being considered a lucrative means of earning money in addition to becoming popular among viewers. To gain these benefits YouTube content creators (YouTubers) need to first attract viewers’ attention to their videos and then persuade them to watch. YouTube metadata, such as the title, thumbnail, description, and keywords, can assist in achieving both objectives. This has been established in the current literature which shows, for example, that metadata optimizing can increase view counts. While these studies have demonstrated the end result of metadata optimization, they do not indicate why viewers respond to different characteristics of metadata in different ways. We contribute to the literature on marketing and consuming YouTube videos by examining, using Holbrook’s (1999) value typology for theorisation, how viewers experience the metadata and how these experiences contribute to the overall value creation process of watching YouTube videos. We employed an interpretive, qualitative research design in conducting the study, using focus group discussions with 21 young YouTube viewers as the data collection method. Data were analysed using thematic analysis. Key findings were that metadata can both deliver value (efficiency) and provide signals about values delivered through the video (excellence and aesthetics). Further, the play value viewers get from interacting with the video is indirectly influenced by the metadata. We also identified that although viewers commonly expect some characteristics in the title and thumbnail, irrespective of their purpose of using YouTube, the importance of each differs when they seek information or entertainment gratification. Further, when value promises made by the metadata are not delivered through the videos, viewers respond negatively. Keywords: Entertainment gratification, Information gratification, Metadata optimization, Value, YouTub

The Three Dimensional Structure of EUV Accretion Regions in AM Herculis Stars: Modeling of EUV Photometric and Spectroscopic Observations

We have developed a model of the high-energy accretion region for magnetic cataclysmic variables and applied it to {\it Extreme Ultraviolet Explorer} observations of 10 AM Herculis type systems. The major features of the EUV light curves are well described by the model. The light curves exhibit a large variety of features such as eclipses of the accretion region by the secondary star and the accretion stream, and dips caused by material very close to the accretion region. While all the observed features of the light curves are highly dependent on viewing geometry, none of the light curves are consistent with a flat, circular accretion spot whose lightcurve would vary solely from projection effects. The accretion region immediately above the WD surface is a source of EUV radiation caused by either a vertical extent to the accretion spot, or Compton scattering off electrons in the accretion column, or, very likely, both. Our model yields spot sizes averaging 0.06 R$_{WD}$, or $f \sim 1 \times 10^{-3}$ the WD surface area, and average spot heights of 0.023 R$_{WD}$. Spectra extracted during broad dip phases are softer than spectra during the out-of-dip phases. This spectral ratio measurement leads to the conclusion that Compton scattering, some absorption by a warm absorber, geometric effects, an asymmetric temperature structure in the accretion region and an asymmetric density structure of the accretion columnare all important components needed to fully explain the data. Spectra extracted at phases where the accretion spot is hidden behind the limb of the WD, but with the accretion column immediately above the spot still visible, show no evidence of emission features characteristic of a hot plasma.Comment: 30 Pages, 11 Figure

Laser Detection and Imaging Techniques for Surface Examination

A coherent laser probe provides the basis for the recording of complex SAW distributions. Using three or more scans, the surface wave velocity can be deducep with an accuracy of a few parts in 105. Such measurements are sufficiently sensitive to detect small changes in surface characteristics; as an example, results will be presented on the effect of doping a Si surface. It is also possible to improve the accuracy of the basic elastic constants of the material by reference to the velocity characteristic. Of particular importance is the fact that this technique provides evidence on the effective value of these constants close to a surface; it is, therefore potentially useful for surface layer characterisation. Surface defects can be detected by means of scattered waves in both the forward as the reverse directions. In principle, either can be used to image the defect. Using both these components, the defect size and location can be determined with improved accuracy

The Cyclotron Fundamental Exposed in the High-Field Magnetic Variable V884 Her

High-quality phase-resolved optical spectropolarimetry is presented for the magnetic cataclysmic variable V884 Her. The overall circular polarization during active accretion states is low and only slightly variable in the range 5000-8000A. However, the polarization is highly structured with wavelength, showing very broad polarization humps, narrow features that are associated with weak absorption lines in the total spectral flux, and sharp reversals across each major emission line. The polarization reversals arise from Zeeman splitting in the funnel gas in a longitudinal magnetic field B~30kG. The set of narrow, polarized absorption features matches the Zeeman pattern of hydrogen for a nearly uniform magnetic field of B=150MG, indicating that the features are "halo" absorption lines formed in a relatively cool reversing layer above the shock. With this identification, the broad polarization humps centered near 7150A and below 4000A are assigned to cyclotron emission from the fundamental and first harmonic (n=2), respectively. V884 Her is only the second AM Her system known with a field exceeding 100MG, and the first case in which the cyclotron fundamental has been directly observed from a magnetic white dwarf.Comment: 14 pages, 6 figures, LaTeX, to appear in The Astrophysical Journal, Part

A proposed checklist for climate-friendly sport and exercise programmes

Background: Fighting the climate crisis is the greatest challenge of our time and will touch all aspects of people's lives. In this context, the United Nations (UN) have called on the sport sector to reduce its negative impacts on the environment and show 'climate leadership'. While some efforts have already been made with regards to mega sport events, there is still a dearth of approaches on limiting the climate impact of recreational sport and exercise programmes. Methods: Based on the UN-Framework 'Sports for Climate Action', literature reviews and additional desk research, a checklist to support local level stakeholders in providing climate-friendly sport and exercise programmes was developed. Results: The proposed checklist consists of five dimensions that need to be considered when designing and offering a climate-friendly sport and exercise programme: (i) active transport to exercise programmes, (ii) the carbon footprint of different types of exercises, (iii) low carbon sport clothing and equipment, (iv) instructors as champions for climate action and (v) advertising and communication. These five dimensions result in a 16-item checklist that supports the planning, advertising, implementation and evaluation of climate-friendly sport and exercise programmes. Conclusions: The proposed checklist intends to facilitate the development of climate-friendly sport and exercise programmes. However, additional work is needed to test the implementation of the checklist at the local level. While the sport sector can make its own contributions to reduce its climate impact, intersectoral action is needed to improve infrastructure for active transport and to build sustainable sport facilities. © 2022 The Author(s). Published by Oxford University Press on behalf of the European Public Health Association.This research was conducted as part of a project funded by the German Federal Ministry of Health (ZMVI1-2521WHO001). The ministry was neither involved in writing this manuscript nor in the decision to submit the article for publication

V405 Aurigae: A High Magnetic Field Intermediate Polar

Our simultaneous multicolor (UBVRI) circular polarimetry has revealed nearly sinusoidal variation over the WD spin cycle, and almost symmetric positive and negative polarization excursions. Maximum amplitudes are observed in the B and V bands (+-3 %). This is the first time that polarization peaking in the blue has been discovered in an IP, and suggests that V405 Aur is the highest magnetic field IP found so far. The polarized flux spectrum is similar to those found in polars with magnetic fields in the range B ~ 25-50 MG. Our low resolution circular spectropolarimetry has given evidence of transient features which can be fitted by cyclotron harmonics n = 6, 7, and 8, at a field of B = 31.5 +- 0.8 MG, consistent with the broad-band polarized flux spectrum. Timings of the circular polarization zero crossovers put strict upper limits on WD spin period changes and indicate that the WD in V405 Aur is currently accreting closely at the spin equilibrium rate, with very long synchronization timescales, T_s > 10^9 yr. For the observed spin to orbital period ratio, P_{spin}/P_{orb} = 0.0365, and P_{orb} ~ 4.15 hr, existing numerical accretion models predict spin equilibrium condition with B ~ 30 MG if the mass ratio of the binary components is q_1 ~ 0.4. The high magnetic field makes V405 Aur a likely candidate as a progenitor of a polar.Comment: To appear in The Astrophysical Journal, September 1 Issue (2008), 9 pages, 10 figure

Spitzer Space Telescope observations of magnetic cataclysmic variables: possibilities for the presence of dust in polars

We present Spitzer Space Telescope photometry of six short-period polars, EF Eri, V347 Pav, VV Pup, V834 Cen, GG Leo, and MR Ser. We have combined the Spitzer Infrared Array Camera (3.6 -8.0 microns) data with the 2MASS J, H, K_s photometry to construct the spectral energy distributions of these systems from the near- to mid-IR (1.235 - 8 microns). We find that five out of the six polars have flux densities in the mid-IR that are substantially in excess of the values expected from the stellar components alone. We have modeled the observed SEDs with a combination of contributions from the white dwarf, secondary star, and either cyclotron emission or a cool, circumbinary dust disk to fill in the long-wavelength excess. We find that a circumbinary dust disk is the most likely cause of the 8 micron excess in all cases, but we have been unable to rule out the specific (but unlikely) case of completely optically thin cyclotron emission as the source of the observed 8 micron flux density. While both model components can generate enough flux at 8 microns, neither dust nor cyclotron emission alone can match the excess above the stellar components at all wavelengths. A model combining both cyclotron and dust contributions, possibly with some accretion-generated flux in the near-IR, is probably required, but our observed SEDs are not sufficiently well-sampled to constrain such a complicated model. If the 8 micron flux density is caused by the presence of a circumbinary dust disk, then our estimates of the masses of these disks are many orders of magnitude below the mass required to affect CV evolution.Comment: 58 pages, 14 figures, ApJ accepte

A 150MG magnetic white dwarf in the cataclysmic variable RX J1554.2+2721

We report the detection of Zeeman-split Lalpha absorption pi and sigma+ lines in the far-ultraviolet Hubble Space Telescope/Space Telescope Imaging Spectrograph spectrum of the magnetic cataclysmic variable RX J1554.2+2721. Fitting the STIS data with magnetic white dwarf model spectra, we derive a field strength of B~144MG and an effective temperature of 17000K<Teff<23000K. This measurement makes RX J1554.2+2721 only the third cataclysmic variable containing a white dwarf with a field exceeding 100MG. Similar to the other high-field polar AR UMa, RX J1554.2+2721 is often found in a state of feeble mass transfer, which suggests that a considerable number of high-field polars may still remain undiscovered.Comment: 4 pages, accepted for ApJ Letter