Search results for "ddc:0"
showing 10 items of 65 documents
Local structure relaxation in nanocrystalline Ni1−xO thin films
2014
Abstract Non-stoichiometric nickel oxide (Ni 1 − x O) thin films were prepared by DC magnetron sputtering technique in mixed Ar/O 2 atmosphere and studied by synchrotron radiation Ni K-edge x-ray absorption spectroscopy, x-ray diffraction and scanning electron microscopy. The use of advanced modelling technique, combining classical molecular dynamics with ab initio multiple-scattering extended x-ray absorption fine structure calculations, allowed us to describe the structure relaxation and dynamics in nanocrystallites and to estimate their size and the concentration of nickel vacancies.
Most Diverse Near-Shortest Paths
2021
Computing the shortest path in a road network is a fundamental problem that has attracted lots of attention. However, in many real-world scenarios, determining solely the shortest path is not enough as users want to have additional, alternative ways of reaching their destination. In this paper, we investigate a novel variant of alternative routing, termed the k-Most Diverse Near-Shortest Paths (kMDNSP). In contrast to previous work, kMDNSP aims at maximizing the diversity of the recommended paths, while bounding their length based on a user-defined constraint. Our theoretical analysis proves the NP-hardness of the problem at hand. To compute an exact solution to kMDNSP, we present an algori…
Using On-Demand File Systems in HPC Environments
2019
In modern HPC systems, parallel (distributed) file systems are used to allow fast access from and to the storage infrastructure. However, I/O performance in large-scale HPC systems has failed to keep up with the increase in computational power. As a result, the I/O subsystem which also has to cope with a large number of demanding metadata operations is often the bottleneck of the entire HPC system. In some cases, even a single bad behaving application can be held responsible for slowing down the entire HPC system, disrupting other applications that use the same I/O subsystem. These kinds of situations are likely to become more frequent in the future with larger and more powerful HPC systems…
How social network sites and other online intermediaries increase exposure to news
2020
Research has prominently assumed that social media and web portals that aggregate news restrict the diversity of content that users are exposed to by tailoring news diets toward the users’ preferences. In our empirical test of this argument, we apply a random-effects within–between model to two large representative datasets of individual web browsing histories. This approach allows us to better encapsulate the effects of social media and other intermediaries on news exposure. We find strong evidence that intermediaries foster more varied online news diets. The results call into question fears about the vanishing potential for incidental news exposure in digital media environments.
Generation Z and Organizational Listening on Social Media
2020
Young people are avid users of social media and have appeared as a powerful force for social change, as shown by the ranks of those who have joined Greta Thunberg in the global climate movement. In addition to challenging political institutions and governments, young people today are also holding the corporate world accountable. To respond to young people’s expectations, brands, and organizations have turned to social media to interact and build relationships with them. However, critics have lamented that these attempts often fail and that young people’s trust in institutions, brands, and organizations continues to decline. This article asks how young people perceive organizational listenin…
Realizing total reciprocity violation in the phase for photon scattering
2017
Scientific reports 7, 43114 (2017). doi:10.1038/srep43114
FlexibleSUSY -- A spectrum generator generator for supersymmetric models
2014
We introduce FlexibleSUSY, a Mathematica and C++ package, which generates a fast, precise C++ spectrum generator for any SUSY model specified by the user. The generated code is designed with both speed and modularity in mind, making it easy to adapt and extend with new features. The model is specified by supplying the superpotential, gauge structure and particle content in a SARAH model file; specific boundary conditions e.g. at the GUT, weak or intermediate scales are defined in a separate FlexibleSUSY model file. From these model files, FlexibleSUSY generates C++ code for self-energies, tadpole corrections, renormalization group equations (RGEs) and electroweak symmetry breaking (EWSB) co…
An absence of neutrinos associated with cosmic-ray acceleration in gamma-ray bursts
2012
Gamma-Ray Bursts (GRBs) have been proposed as a leading candidate for acceleration of ultra high-energy cosmic rays, which would be accompanied by emission of TeV neutrinos produced in proton-photon interactions during acceleration in the GRB fireball. Two analyses using data from two years of the IceCube detector produced no evidence for this neutrino emission, placing strong constraints on models of neutrino and cosmic-ray production in these sources.
Disinformation in Facebook Ads in the 2019 Spanish General Election Campaigns
2021
Producción Científica
The Rocky Road towards Professional Autonomy : The Estonian Journalists’ Organization in the Political Turmoil of the 20th Century
2017
This article attempts to explain the relationships between journalists, politics and the state from the perspective of collective autonomy, that of the professional organization of journalists. The case of Estonian Journalists’ Union demonstrates the complexity and historical contingency of professional autonomy of journalism. The development of the Estonian journalists’ organization occurred as a sequence of transformations from the Estonian Journalists’ Association to the Estonian Journalists’ Union to the Soviet type journalists’ union, and lastly to an independent trade union. This sequence was disrupted by several fatal breakdowns that changed not only the character of the association,…