3,456 research outputs found
Technofixing the Future: Ethical Side Effects of Using AI and Big Data to meet the SDGs
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
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
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 with
where is the lensing impact parameter, , is the
mass of the lens and 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 . 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 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
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
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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