921 research outputs found

    How Likely Are Viewers to Watch Television Commercials: A Connectedness Perspective

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    With the recent return to more advertising-generated content by entertainment providers, it again becomes important to understand what will drive consumers to view commercials. We utilize the construct of television connectedness developed by Russell, Norman, and Heckler (2004) to predict viewers’ propensity to watch television commercials. Based on data derived from a survey completed by 816 residents of the United States, we estimate a logistic regression model and find that older (35+) viewers high on connectedness are more likely to view television commercials. We further employ correspondence analysis of free-response data to uncover differences in motivations to view commercials among younger (18-34) and older (35+) consumers with different connectedness levels. We discuss implications for television networks and subscription-video-on-demand (SVOD, streaming) providers that seek to enhance revenue with advertising-supported content on their platforms

    Simulation approach for assessing the performance of the γEWMA control chart

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    i) Purpose: The purpose of this paper is to evaluate the performance of a modified EWMA control chart (γ\gammaEWMA control chart), which considers data distribution and incorporate its correlation structure, simulating in-control and out-of-control processes and to select an adequate value for smoothing parameter with these conditions. ii) Design/methodology/approach: This paper is based on a simulation approach using the methodology for evaluating statistical methods proposed by Morris et al. (2019). Data were generated from a simulation considering two factors that associated with data: (1) quality variable distribution skewness as an indicator of quality variable distribution; (2) the autocorrelation structure for type of relationship between the observations and modeled by AR(1). In addition, one factor associated with the process was considered, (1) the shift in the process mean. In the following step, when the chart control is modeled, the fourth factor intervenes. This factor is a smoothing parameter. Finally, three indicators defined from the Run Length are used to evaluate γEWMA control chart performance this factors and their interactions. iii) Findings: Interaction analysis for four factor evidence that the modeling and selection of parameters is different for out-of-control and in-control processes therefore the considerations and parameters selected for each case must be carefully analyzed. For out-of-control processes, it is better to preserve the original features of the distribution (mean and variance) for the calculation of the control limits. It makes sense that highly autocorrelated observations require smaller smoothing parameter since the correlation structure enables the preservation of relevant information in past data. iv) Originality/value: The γ\gammaEWMA control chart there has advantages because it gathers, in single chart control: the process and modelling characteristics, and data structure process. Although there are other proposals for modified EWMA, none of them simultaneously analyze the four factors nor their interactions. The proposed γ\gammaEWMA allows setting the appropriate smoothing parameter when these three factors are considered

    A virtual sensor for electric vehicles’ state of charge estimation

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    The estimation of the state of charge is a critical function in the operation of electric vehicles. The battery management system must provide accurate information about the battery state, even in the presence of failures in the vehicle sensors. This article presents a new methodology for the state of charge estimation (SOC) in electric vehicles without the use of a battery current sensor, relying on a virtual sensor, based on other available vehicle measurements, such as speed, battery voltage and acceleration pedal position. The estimator was derived from experimental data, employing support vector regression (SVR), principal component analysis (PCA) and a dual polarization (DP) battery model (BM). It is shown that the obtained model is able to predict the state of charge of the battery with acceptable precision in the case of a failure of the current sensor

    Spectral optical monitoring of the double peaked emission line AGN Arp 102B: II. Variability of the broad line properties

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    We investigate a long-term (26 years, from 1987 to 2013) variability in the broad spectral line properties of the radio galaxy Arp 102B, an active galaxy with broad double-peaked emission lines. We use observations presented in Paper I (Shapovalova et al. 2013) in the period from 1987 to 2011, and a new set of observations performed in 2012--2013. To explore the BLR geometry, and clarify some contradictions about the nature of the BLR in Arp 102B we explore variations in the Hα\alpha and Hβ\beta line parameters during the monitored period. We fit the broad lines with three broad Gaussian functions finding the positions and intensities of the blue and red peaks in Hα\alpha and Hβ\beta. Additionally we fit averaged line profiles with the disc model. We find that the broad line profiles are double-peaked and have not been changed significantly in shapes, beside an additional small peak that, from time to time can be seen in the blue part of the Hα\alpha line. The positions of the blue and red peaks { have not changed significantly during the monitored period. The Hβ\beta line is broader than Hα\alpha line in the monitored period. The disc model is able to reproduce the Hβ\beta and Hα\alpha broad line profiles, however, observed variability in the line parameters are not in a good agreement with the emission disc hypothesis. It seems that the BLR of Arp 102B has a disc-like geometry, but the role of an outflow can also play an important role in observed variation of the broad line properties.Comment: 17 pages, Accepted for publication in A&

    Fluids in the treatment of diabetic ketoacidosis in children:A systematic review

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    Aim: To determine the comparative effectiveness of fluid schemes for children with diabetic ketoacidosis (DKA). Methods: We conducted a systematic review with an attempt to conduct network meta-analysis (NMA). We searched MEDLINE, EMBASE, CENTRAL, Epistemonikos, Virtual Health Library, and gray literature from inception to July 31, 2022. We included randomized controlled trials (RCTs) in children with DKA evaluating any intravenous fluid schemes. We planned to conduct NMA to compare all fluid schemes if heterogeneity was deemed acceptable. Results: Twelve RCTs were included. Studies were heterogeneous in the population (patients and DKA episodes), interventions with different fluids (saline, Ringer's lactate (RL), and polyelectrolyte solution-PlasmaLyte®), tonicity, volume, and administration systems. We identified 47 outcomes that measured clinical manifestations and metabolic control, including single and composite outcomes and substantial heterogeneity preventing statistical combination. No evidence was found of differences in neurological deterioration (main outcome), but differences were found among interventions in some comparisons to normalize acid-base status (∼2 h less with low vs. high volume); time to receive subcutaneous insulin (∼1 h less with low vs. high fluid rate); length of stay (∼6 h less with RL vs. saline); and resolution of the DKA (∼3 h less with two-bag vs. one-bag scheme). However, available evidence is scarce and poor. Conclusions: There is not enough evidence to determine the best fluid therapy in terms of fluid type, tonicity, volume, or administration time for DKA treatment. There is an urgent need for more RCTs, and the development of a core outcome set on DKA in children.</p

    Percolating contacts network and force chains during interface shear in granular media

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    The concept of force chains transmitting stress through granular materials is well established; however identification of individual force chains and the associated quantitative analysis is non-trivial. This paper proposes two algorithms to (1) find the network of percolating contacts that control the response of loaded granular media, and (2) decompose this network into the individual force chains that comprise it. The new framework is demonstrated considering data from discrete element method simulations of a ribbed interface moving against a granular sample. The subset of contacts in the material that transfers load across the sample, namely the percolating contact network (G perc), is found using the maximum flow algorithm. The resulting network is fully-connected and its maximum flow value corresponds to the force percolating the system in the direction normal to the ribbed wall. G perc re-orientates in response to the ribbed interface movement and transmits 85–95% of the stress, with only 40–65% of the contacts in the sample. Then, is split into individual force chains using a novel implementation of the widest path problem. Results show that denser materials with increased force-chain centrality promote a higher density of force chains, which results in a higher macro-scale strength during interface shearing. The contribution of force chains in the network is revealed to be highly centralized, composed by a small set of strong and long-lived force chains, plus a large set of weak and short-lived force chains

    OPTICAL SPECTROSCOPIC OBSERVATIONS OF GAMMA-RAY BLAZAR CANDIDATES. VI. FURTHER OBSERVATIONS FROM TNG, WHT, OAN, SOAR, AND MAGELLAN TELESCOPES

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    Indexación: Web of ScienceBlazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of.-ray sources, and their number is continuously growing in the Fermi catalogs. However, in the latest release of the Fermi catalog there is still a large fraction of sources that are classified as blazar candidates of uncertain type (BCUs) for which optical spectroscopic observations are necessary to confirm their nature and their associations. In addition, about one-third of the gamma-ray point sources listed in the Third Fermi-LAT Source Catalog (3FGL) are still unassociated and lacking an assigned lower-energy counterpart. Since 2012 we have been carrying out an optical spectroscopic campaign to observe blazar candidates to confirm their nature. In this paper, the sixth of the series, we present optical spectroscopic observations for 30 gamma-ray blazar candidates from different observing programs we carried out with the Telescopio Nazionale Galileo, William Herschel Telescope, Observatorio Astronomico Nacional, Southern Astrophysical Research Telescope, and Magellan. Telescopes. We found that 21 out of 30 sources investigated are BL Lac objects, while the remaining targets are classified as flat-spectrum radio quasars showing the typical broad emission lines of normal quasi-stellar objects. We conclude that our selection of gamma-ray blazar. candidates based on their multifrequency properties continues to be a successful way to discover potential low-energy counterparts of the Fermi. unidentified gamma-ray sources and to confirm the nature of BCUs.http://iopscience.iop.org/article/10.3847/0004-6256/151/4/95/met
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