3,456 research outputs found

    Technofixing the Future: Ethical Side Effects of Using AI and Big Data to meet the SDGs

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    While the use of smart information systems (the combination of AI and Big Data) offer great potential for meeting many of the UN’s Sustainable Development Goals (SDGs), they also raise a number of ethical challenges in their implementation. Through the use of six empirical case studies, this paper will examine potential ethical issues relating to use of SIS to meet the challenges in six of the SDGs (2, 3, 7, 8, 11, and 12). The paper will show that often a simple “technofix”, such as through the use of SIS, is not sufficient and may exacerbate, or create new, issues for the development community using SIS

    The Dynamic Integrated Approach to teacher professional development: rationale and main characteristics

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    This paper refers to the Dynamic Integrated Approach towards teacher professional development which attempts to merge research findings on teacher effectiveness and teacher professional development. The theoretical framework and the major features of the DIA are presented. It is argued that the DIA can be effectively implemented through five steps: Establishing clarity and consensus about aims and objectives, identifying needs and priorities for improvement through empirical investigation, provision of improvement guidelines, reflection opportunities and coaching on effective teaching by the advisory and research team, establishing a formative evaluation mechanism and finally establishing a summative evaluation system. Results of empirical studies providing support to the basic elements and the overall effectiveness of the DIA are also presented. Implications of the findings are discussed and suggestions for further research, particularly in exploring the conditions under which the DIA could have a long lasting effect on teacher effectiveness, are finally drawn.This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/13664530.2015.107955

    Probing dark fluids and modified gravity with gravitational lensing

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    We generalize the Rindler-Ishak (2007) result for the lensing deflection angle in a SdS spacetime, to the case of a general spherically symmetric fluid beyond the cosmological constant. We thus derive an analytic expression to first post-Newtonian order for the lensing deflection angle in a general static spherically symmetric metric of the form ds2=f(r)dt2dr2f(r)r2(dθ2+sin2θdϕ2) ds^2 = f(r)dt^{2} -\frac{dr^{2}}{f(r)}-r^{2}(d\theta ^2 +\sin ^2 \theta d\phi ^2) with f(r)=12mribi  r0qi  (r0r)qif(r) = 1 - \frac{2m}{r}-\sum_{i} b_i\; r_0^{-q_i}\; \left( \frac{r_0}{r}\right)^{q_i} where r0r_0 is the lensing impact parameter, bir0qib_i\ll r_0^{q_i}, mm is the mass of the lens and qiq_i are real arbitrary constants related to the properties of the fluid that surrounds the lens or to modified gravity. This is a generalization of the well known Kiselev black hole metric. The approximate analytic expression of the deflection angle is verified by an exact numerical derivation and in special cases it reduces to results of previous studies. The density and pressure of the spherically symmetric fluid that induces this metric is derived in terms of the constants bib_i. The Kiselev case of a Schwarzschild metric perturbed by a general spherically symmetric dark fluid (eg vacuum energy) is studied in some detail and consistency with the special case of Rindler Ishak result is found for the case of a cosmological constant background. Observational data of the Einstein radii from distant clusters of galaxies lead to observational constraints on the constants bib_i and through them on the density and pressure of dark fluids, field theories or modified gravity theories that could induce this metric.Comment: 9 pages, 4 Figures, 2 Tables. Published in MNRAS. The Mathematica files used for the construction of Fig. 2 and 3 may be downloaded from https://github.com/leandros11/lensing

    A new model for the structure of the DACs and SACs regions in the Oe and Be stellar atmospheres

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    In this paper we present a new mathematical model for the density regions where a specific spectral line and its SACs/DACs are created in the Oe and Be stellar atmospheres. In the calculations of final spectral line function we consider that the main reasons of the line broadening are the rotation of the density regions creating the spectral line and its DACs/SACs, as well as the random motions of the ions. This line function is able to reproduce the spectral feature and it enables us to calculate some important physical parameters, such as the rotational, the radial and the random velocities, the Full Width at Half Maximum, the Gaussian deviation, the optical depth, the column density and the absorbed or emitted energy. Additionally, we can calculate the percentage of the contribution of the rotational velocity and the ions' random motions of the DACs/SACs regions to the line broadening. Finally, we present two tests and three short applications of the proposed model.Comment: 9 pages, 5 figures, accepted for publication in PAS

    Criticality, Fractality and Intermittency in Strong Interactions

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    Assuming a second-order phase transition for the hadronization process, we attempt to associate intermittency patterns in high-energy hadronic collisions to fractal structures in configuration space and corresponding intermittency indices to the isothermal critical exponent at the transition temperature. In this approach, the most general multidimensional intermittency pattern, associated to a second-order phase transition of the strongly interacting system, is determined, and its relevance to present and future experiments is discussed.Comment: 15 pages + 2 figures (available on request), CERN-TH.6990/93, UA/NPPS-5-9
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