Interaction of a Moreton/EIT wave and a coronal hole

We report high-cadence H-alpha observations of a distinct Moreton wave observed at Kanzelhoehe Solar Observatory associated with the 3B/X3.8 flare and CME event of 2005 January 17. The Moreton wave can be identified in about 40 H-alpha frames over a period of 7 min. The EIT wave is observed in only one frame but the derived propagation distance is close to that of the simultaneously measured Moreton wave fronts indicating that they are closely associated phenomena. The large angular extent of the Moreton wave allows us to study the wave kinematics in different propagation directions with respect to the location of a polar coronal hole (CH). In particular we find that the wave segment whose propagation direction is perpendicular to the CH boundary (``frontal encounter'') is stopped by the CH which is in accordance with observations reported from EIT waves (Thompson et al. 1998). However, we also find that at a tongue-shaped edge of the coronal hole, where the front orientation is perpendicular to the CH boundary (the wave ``slides along'' the boundary), the wave signatures can be found up to 100 Mm inside the CH. These findings are briefly discussed in the frame of recent modeling results.Comment: 14 pages, 6 figures, accepted for publication in the Ap

Quasi-one and two-dimensional transitions of gases adsorbed on nanotube bundles

Grand canonical Monte Carlo simulations have been performed to determine the adsorption behavior of Ar and Kr atoms on the exterior surface of a rope (bundle) consisting of many carbon nanotubes. The computed adsorption isotherms reveal phase transitions associated with the successive creation of quasi-one dimensional lines of atoms near and parallel to the intersection of two adjacent nanotubes.Comment: 12 pages, 6 figures, submitted to J. Chem. Phy

Neural Dynamic Movement Primitives -- a survey

One of the most important challenges in robotics is producing accurate trajectories and controlling their dynamic parameters so that the robots can perform different tasks. The ability to provide such motion control is closely related to how such movements are encoded. Advances on deep learning have had a strong repercussion in the development of novel approaches for Dynamic Movement Primitives. In this work, we survey scientific literature related to Neural Dynamic Movement Primitives, to complement existing surveys on Dynamic Movement Primitives

Perceptions of private security : a case study of students from Serbia and North Macedonia

In the last two decades of the 21st century, the significant development of the private security industry has taken place in Serbia and North Macedonia. However, the private security industry in these two countries did not reach professional standards as in other states of the former Yugoslavia. The aim of this paper was to determine students’ perception of private security and its employees. The survey data were collected using an anonymous survey of 354 students (296 from Serbia and 58 from North Macedonia). In both countries the attitudes are heterogeneous, but a relatively small number of respondents have expressed a high level of perception of private security. The research has shown that gender, as one of demographic characteristics, has its role in shaping young pexople’s views on the private security, that is, the female population has more positive views about private security officers, their integrity, and the nature of the private security job. The findings offer policy-makers and private security companies the opportunity to deploy new strategies to upgrade public attitudes towards private security, especially aimed at the male population