6,191 research outputs found

    Dissecting Non-Use of Online News – Systematic Evidence from Combining Tracking and Automated Text Classification

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    A high proportion of non-users of news is considered a concern for a functioning democracy. However, existing empirical assessments on the share of news avoiders rely exclusively on survey data and the results vary drastically between studies, making it difficult to evaluate the severity of the issue. This study relies on tracking data of Swiss Internet users and applies and discusses two computational methods, identifying news at the domain and article level, to realistically assess the extent of non-users of online news. Results indicate that at least 14.2% of Internet users do not use news online. Furthermore, this study suggests that identifying news use solely based on tracking data at the domain level is distorted by a faux news effect, i.e., non-news use on news domains, and an invisible news effect, i.e., news use on small and unknown news domains. The parallel use of tracking data and supervised text classification allows to dissect and discuss these effects systematically. Similarly, it is found that not accounting for news use via apps overestimates the extent of non-use of online news. The findings provide valuable insights for future applications of these methods in similar contexts

    Testing the Reliability of ChatGPT for Text Annotation and Classification: A Cautionary Remark

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    Recent studies have demonstrated promising potential of ChatGPT for various text annotation and classification tasks. However, ChatGPT is non-deterministic which means that, as with human coders, identical input can lead to different outputs. Given this, it seems appropriate to test the reliability of ChatGPT. Therefore, this study investigates the consistency of ChatGPT's zero-shot capabilities for text annotation and classification, focusing on different model parameters, prompt variations, and repetitions of identical inputs. Based on the real-world classification task of differentiating website texts into news and not news, results show that consistency in ChatGPT's classification output can fall short of scientific thresholds for reliability. For example, even minor wording alterations in prompts or repeating the identical input can lead to varying outputs. Although pooling outputs from multiple repetitions can improve reliability, this study advises caution when using ChatGPT for zero-shot text annotation and underscores the need for thorough validation, such as comparison against human-annotated data. The unsupervised application of ChatGPT for text annotation and classification is not recommended.Comment: First uploaded on Dropbox on 5th of April. See https://twitter.com/mv_reiss/status/1643916531720486913, content was not changed except for formattin

    Anomalous Hall effect in the Co-based Heusler compounds Co2_{2}FeSi and Co2_{2}FeAl

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    The anomalous Hall effect (AHE) in the Heusler compounds Co2_{2}FeSi and Co2_{2}FeAl is studied in dependence of the annealing temperature to achieve a general comprehension of its origin. We have demonstrated that the crystal quality affected by annealing processes is a significant control parameter to tune the electrical resistivity ρxx\rho_{xx} as well as the anomalous Hall resistivity ρahe\rho_{ahe}. Analyzing the scaling behavior of ρahe\rho_{ahe} in terms of ρxx\rho_{xx} points to a temperature-dependent skew scattering as the dominant mechanism in both Heusler compounds

    Scanning the critical fluctuations -- application to the phenomenology of the two-dimensional XY-model --

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    We show how applying field conjugated to the order parameter, may act as a very precise probe to explore the probability distribution function of the order parameter. Using this `magnetic-field scanning' on large-scale numerical simulations of the critical 2D XY-model, we are able to discard the conjectured double-exponential form of the large-magnetization asymptote.Comment: 4 pages, 4 figure

    Relativistic photoelectron spectra in the ionization of atoms by elliptically polarized light

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    Relativistic tunnel ionization of atoms by intense, elliptically polarized light is considered. The relativistic version of the Landau-Dykhne formula is employed. The general analytical expression is obtained for the relativistic photoelectron spectra. The most probable angle of electron emission, the angular distribution near this angle, the position of the maximum and the width of the energy spectrum are calculated. In the weak field limit we obtain the familiar non-relativistic results. For the case of circular polarization our analytical results are in agreement with recent derivations of Krainov [V.P. Krainov, J. Phys. B, {\bf 32}, 1607 (1999)].Comment: 8 pages, 2 figures, accepted for publication in Journal of Physics

    Relativistic semiclassical approach in strong-field nonlinear photoionization

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    Nonlinear relativistic ionization phenomena induced by a strong laser radiation with elliptically polarization are considered. The starting point is the classical relativistic action for a free electron moving in the electromagnetic field created by a strong laser beam. The application of the relativistic action to the classical barrier-suppression ionization is briefly discussed. Further the relativistic version of the Landau-Dykhne formula is employed to consider the semiclassical sub-barrier ionization. Simple analytical expressions have been found for: (i) the rates of the strong-field nonlinear ionization including relativistic initial and final state effects; (ii) the most probable value of the components of the photoelectron final state momentum; (iii) the most probable direction of photoelectron emission and (iv) the distribution of the photoelectron momentum near its maximum value.Comment: 13 pages, 3 figures, to be published in Phys. Rev.

    Perceiving education from Facebook profile pictures

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    Our upbringing and education influence not only how we present and distinguish ourselves in the social world but also how we perceive others. We apply this central sociological idea to the social media context. We conduct a large-scale online study to investigate whether observers can correctly guess the education of others from their Facebook profile pictures. Using the binomial test and cross-classified mixed-effects models, we show that observers can assess the education of depicted persons better than chance, especially when they share the same educational background and have experience with the social media. We also find that posting pictures of outdoor activities is a strong signal of having higher education, while professional photographs can obscure education signals. The findings expand our knowledge of social interaction and self-expression online and offer new insights for understanding social influence on social media

    Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method

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    The determination of the longitudinal spin Seebeck effect (LSSE) coefficient is currently plagued by a large uncertainty due to the poor reproducibility of the experimental conditions used in its measurement. In this work we present a detailed analysis of two different methods used for the determination of the LSSE coefficient. We have performed LSSE experiments in different laboratories, by using different setups and employing both the temperature difference method and the heat flux method. We found that the lack of reproducibility can be mainly attributed to the thermal contact resistance between the sample and the thermal baths which generate the temperature gradient. Due to the variation of the thermal resistance, we found that the scaling of the LSSE voltage to the heat flux through the sample rather than to the temperature difference across the sample greatly reduces the uncertainty. The characteristics of a single YIG/Pt LSSE device obtained with two different setups was (1.143±0.007)107(1.143\pm0.007)\cdot 10^{-7} Vm/W and (1.101±0.015)107(1.101\pm0.015)\cdot 10^{-7} Vm/W with the heat flux method and (2.313±0.017)107(2.313\pm0.017)\cdot 10^{-7} V/K and (4.956±0.005)107(4.956\pm0.005)\cdot 10^{-7} V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.Comment: PDFLaTeX, 10 pages, 6 figure

    Beta decay and other processes in strong electromagnetic fields

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    We consider effects of the fields of strong electromagnetic waves on various characteristics of quantum processes. After a qualitative discussion of the effects of external fields on the energy spectra and angular distributions of the final-state particles as well as on the total probabilities of the processes (such as decay rates and total cross sections), we present a simple method of calculating the total probabilities of processes with production of non-relativistic charged particles. Using nuclear beta-decay as an example, we study the weak and strong field limits, as well as the field-induced beta-decay of nuclei stable in the absence of the external fields, both in the tunneling and multi-photon regimes. We also consider the possibility of accelerating forbidden nuclear beta-decays by lifting the forbiddeness due to the interaction of the parent or daughter nuclei with the field of a strong electromagnetic wave. It is shown that for currently attainable electromagnetic fields all effects on total beta-decay rates are unobservably small.Comment: LaTeX, 30 pages, 2 figures. Invited contribution to the special issue of Yadernaya Fizika dedicated to the centennial anniversary of birthday of A.B. Migdal. V2: references adde

    Commercial fishing vessel as research vessels in the Antarctic – requirements and solutions exemplified with a new vessel

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    The climate-induced changes presently seen in the ecosystems of the Antarctic region require a precautionary approach with respect to the human use of these ecosystems. In particular, resource harvesting requires enough basic knowledge, as well as adequate monitoring, to avoid unintended impacts on the harvested stocks and the associated ecosystem. Due to the vastness and remoteness of the Antarctic region, research vessel capacity is not readily available for conventional coverage of harvested stocks and their ecosystems. This paper describes the potential of using commercial fishing vessels to bridge the gap in research vessel capacity. The various tasks and required instrumentation are presented and discussed. To illustrate this concept a description of a Norwegian krill fishing vessel now under construction is presented. This type of combined fishing and research vessel could make a large amount of important data available for both management, through CCAMLR, and the broader scientific community and thus improve the basis for resource evaluation and management
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