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Doctoral colloquium - František Dráček (3.4.2023)

Damas.Gruska@fmph.uniba.sk — Thu, 30 Mar 2023 16:03:00 +0200

František Dráček:
Anomaly detection from TLE data
Abstract:
The rapidly growing number of objects in the Low Earth Orbit presents a significant challenge for satellite operators to ensure that satellites do not collide with other objects, which could lead to the loss of the satellite, or worse, it could cause the shattering of the satellites. A significant research effort is devoted to assessment of close conjunction close conjunction risks. Most such approaches rely on Two line element data (TLE). TLEs contains orbital elements of space object at a specific time. Aside from estimating collision risks, TLEs are used to calculate re-entry, used for drag make-up and space weather estimation. Our aim is to identify and study anomalies in the TLE data. The anomalies are in some cases related to the errors in the measurement, but also errors caused by their osculating(averaged) character.

We increase cyber security

milos.hrabovsky@uniba.sk — Wed, 29 Mar 2023 16:05:00 +0200

For the average user, this means that in addition to their email password, they will also have to verify their identity using another authentication tool, such as their mobile phone. Therefore, if you plan to travel abroad (outside of Slovakia, Czechia, Hungary, and Austria) for work or personal reasons and need to access your university email account, it is necessary to set up MFA on your mobile phone before your trip.

This can be done directly from your web browser on your computer using this link: https://account.activedirectory.windowsazure.com/Proofup.aspx.

Instructions for setting up MFA can be found here.

We urge all users to be extra careful when evaluating emails offering links to change passwords and any other attempts to obtain unauthorized access to data.

Seminar of Graph Theory - Martin Škoviera (30.3.2023)

Martin.Skoviera@fmph.uniba.sk — Mon, 27 Mar 2023 16:24:00 +0200

Martin Škoviera:
Resistance and flow resistance in cubic graphs

Abstract:
We examine the relationship between two measures of uncolourability of cubic graphs -- their resistance and flow resistance. The resistance of a cubic graph G, denoted by r(G), is the minimum number of edges whose removal results in a 3-edge-colourable graph. The flow resistance of G, denoted by r_f(G), is the minimum number of zeroes in a 4-flow on G. Fiol et al. (2018) made a conjecture that r_f(G) never exceeds r(G). We disprove this conjecture by presenting a family of cubic graphs G_n with resistance n and flow resistance 2n. We also present another family H_n where resistance is 2 and flow resistance is n, demonstrating that the ratio r_f(G)/r(G) can be arbitrarily large. Members of both families are nontrivial snarks. The talk is based on joint results with Imran Allie (University of Cape Town) and Edita Macajova. More information

Digital Workshop: Data Carpentry Ecology

Mon, 27 Mar 2023 10:14:00 +0200

Dear students, Would you like to improve your data skills? Do you know how to analyse, visualize and manage data in order to help your research conduction? We are pleased to invite you to digital workshop of the University of Göttingen open for ENLIGHT students. From the 24^th to 28^th of April, the University of Göttingen offers a digital workshop on ‘Data Carpentry for Ecologists’ that will provide you with basic data skills and an introduction to the use of data tools (OpenRefine, R) necessary for conducting research. This workshop is open for Bachelor, Master or PhD students from all ENLIGHT universities, particularly within the fields of Ecology, Biology, Forestry and Agriculture. Participants are encouraged to help each other and apply what they have learned to their own research problems. Participants who complete the assessment of the workshop will receive a digital badge of the University of Göttingen within the competence area of digitalisation. The badge illustrates a digital proof of competence, is verifiable online and can be shared on social media or used in application processes. For further information on the UGOE digital badge please click here.

Are you interested?

Please register for this digital workshop by 14^th of April 2023 via the following zoom registration. Be aware that the workshop will be open for max. 18 participants from all ENLIGHT universities. If you have any further questions, please contact Birgit Schmidt, bschmidt@sub.uni-goettingen.de.

RECTOR'S AND DEAN'S DAY OFF

Mon, 27 Mar 2023 07:21:00 +0200

On occasion of the Easter holidays, the rector of Comenius University Bratislava grants the...

Nuclear Seminar - Pavel Povinec (29.3.2023)

Jaroslav.Stanicek@fmph.uniba.sk — Sat, 25 Mar 2023 23:49:00 +0100

prof. RNDr. Pavel Povinec, DrSc.:
Quo Vadis, AMS? Abstract:
Many scientific investigations from very different scientific fields have been crucially depending on the sensitivity, accuracy and precision of radionuclide measurements in various types of samples, and on possible contamination of instruments with natural radionuclides (e.g., K-40, and Th-232 and U-238 decay series products). We may mention, e.g., investigations of rare nuclear processes and decays in large-scale underground experiments searching for neutrinoless double beta-decays of nuclei with target masses of about one ton (e.g., for Ge-76 [1] and Xe-136 [2]), as well as searchers for dark matter represented by low mass (< 1 GeV/c2) or high mass particles [e.g., 3,4]. On the other hand, direct radionuclide analyses with high precision in very small samples have also been challenging processes requiring a very low instrumental background and high efficiency, which has been well demonstrated, e.g., in climate change studies using isotope archives (C-14 in tree rings, Be-10 and Cl-36 in ice cores [5, 6]). With development of the ultra-sensitive AMS (Accelerator Mass Spectrometry), these investigations have been feasible. We shall review the past achievements of AMS, and discuss possible applications in the future, especially in connection with the recently installed AMS beam line at the CENTA laboratory. 1. Abgrall N et al., LEGEND Collaboration (2021). The large enriched germanium experiment for neutrinoless ββ decay. arXiv:2107.11462v1 [physics.ins-det]. 2. Aprile E et al., XENON Collaboration (2022). Double-weak decays of 124Xe and 136Xe in the XENON1T and XENONnT experiments. arXiv:2205.04158v1 [hep-ex] 9. 3. Angloher G et al., CRESST collaboration (2022). Latest observations on the low energy excess in CRESST-III”. arXiv:2207.09375. 4. Aalbers J. et al., Xenon Collaboration (2023). A next-generation liquid xenon observatory for dark matter and neutrino physics. J. Phys. G: Nucl. Part. Phys. 50 013001. 5. Reimer P et al 2020. The IntCal20 Northern Hemisphere radiocarbon age calibration curve (0–55 cal kBP). Radiocarbon 62: 725–757. 6. Kanzava K et al (2021) Dome Fuji Ice Core (∼100 Years Around 5480 BCE): An Unusual Grand Solar Minimum Occurrence? J. Geophys. Res. Space Phys. 126, e2021JA029378.

Comenius University received evaluation in four subjects in the QS WUR by Subject rankings

pr@uniba.sk — Tue, 28 Mar 2023 11:33:00 +0200

Comenius University achieved the best ranking in the area of petroleum engineering research, in the 151st-160th place band. In the area of agriculture and forestry research, it ranked 351st-400th. In medicine it ranked 451st-500th and ended up in the same band in physics and astronomy. Comenius University was ranked in the 651st-700th place band in the main QS WUR ranking, and the next ranking will be published in June. The evaluation covered over 15,700 academic programmes identified by QS at 1,594 institutions. They are grouped into 54 subject areas, including three new ones: data science, history of art and marketing. These areas do not always align with study programmes offered by the universities. This explains why CU ranks so well in areas like petroleum engineering or agriculture and forestry, which are not taught at our university. Researchers at several CU faculties contribute to these areas with their scientific research. If their papers are highly cited and are part of international research, they improve the overall rating. The QS WUR by Subject ranking evaluates universities according to five indicators with different weights: academic reputation, employer reputation, research citations per paper according to Elsevier Scopus, H-index of researchers, international research network. Besides Comenius University, the rankings also include the Slovak University of Agriculture, ranked in one subject: agriculture and forestry, placing in the 151st-200th band. The third school from Slovakia is the University of Constantine the Philosopher in Nitra which was evaluated in philosophy, achieving the 201st-210th position band. Before now, no Slovak university managed to rank in any of the five main areas. Since 2015, however, Comenius University has been evaluated in at least one subject. In the V4 group of countries, Slovakia lags in the number of placements despite comparable performance. *** Comenius University is the only Slovak university which regularly appears in all prominent rankings. Last year, it reached the 651st-700th place band in the overall ranking of the QS World University Rankings. In the Round University Ranking, it ranked 426th overall and 178th in the education category. In ARWU ranking (Shanghai ranking) it placed in the 701st-800th place band. It is currently 630th in the CWUR ranking. The prestigious Best Global Universities ranking ranks it 639th overall, and 266th in physics. The SCImago ranking lists it in 573rd place. In the NTU Ranking (National Taiwan University Rankings) it is ranked 701st-750th, while in the subject of physics it is ranked 301st-350th worldwide. It ranks 284th in The Three University Missions MosIUR, and THE Impact Rankings puts it in the 601st-800th place band. THE WUR ranking puts Comenius University in the 1001st - 1200th place band overall. World University Ranking RankPro ranks it in the 260th place.

Five new Professors from Comenius University

pr@uniba.sk — Fri, 24 Mar 2023 08:10:00 +0100

The newly appointed Professors include:

Assoc. Prof. JUDr. Mgr. Martina Gajdošová, PhD., theory and history of the state and law, Faculty of Law, CU,
Assoc. Prof. Mgr. Martin Hurbanič, PhD., general history, Faculty of Arts, CU,
Assoc. Prof. PhDr. Daniel Lančarič, PhD., general linguistics, Faculty of Arts, CU,
Assoc. Prof. JUDr. Tomáš Ľalík, PhD., constitutional law, Faculty of Law, CU,
Assoc. Prof. JUDr. Romana Smyčková, PhD., civil law, Faculty of Law, CU.

According to the Head of State, a mature democratic and civil society needs a functioning legal framework. "It needs citizens who know history in order to be able to understand the present. It needs an educated and enlightened population capable of critical thinking. It needs people who are literate in matters of economy and law, but also in social affairs and culture, citizens with a sense of justice and a sensitivity for the environment, with respect for the norms and values that define our relationships and that qualify us to be a viable and considerate human community," she said. According to President Čaputová, a democratic and civil society needs culture in the broadest sense, and the humanities play a key role in it.

Doctoral colloquium - Lukáš Gajdošek (27.3.2023)

Damas.Gruska@fmph.uniba.sk — Thu, 23 Mar 2023 09:37:00 +0100

Lukáš Gajdošek:
Evolution of Fusion on High-Quality Depth Data Abstract:
The availability of 3D sensors acquiring depth data caused the rise of interest in the problem of registering depth maps from a sequence with unknown transformation into a common space. Usually, surface reconstruction of the growing point cloud is performed on the fly. This procedure is known as a Fusion, and it has been a popular topic since 2011 with the release of the KinectFusion paper. A similar task in robotics, when only 2D images are available, is called Structure from Motion. Nowadays, both RGB cameras and depth sensors are available in much higher resolution, with better exposure control and higher framerates. In this presentation, we will do a chronological overview of the papers regarding the Fusion problem and available datasets. Then, we will present data obtained using a novel structured light based-sensor resulting in high 1120x800 resolution depth maps obtained in real-time. This sensor is used primarly in industrial settings. Some sequences are designed to be hard, with rapid movement between the frames, circular motion, and symmetrical objects, where the transformation calculation using only geometry data is ill-defined. On this data, we will compare the results of traditional pipelines with detectors like AKAZE for texture features versus a hybrid, where a neural network is used for obtaining texture correspondences.

Doctoral colloquium - Dominika Mihálová (27.3.2023)

Damas.Gruska@fmph.uniba.sk — Thu, 23 Mar 2023 09:26:00 +0100

Dominika Mihálová:
Optimal structures based on algebraic constructions
Abstract:
The use of computers to solve problems in the field of mathematics has become more important with the growing complexity of the considered problems. In our work, we focus on two different problems: the Cage problem from the area of Extremal Graph Theory and the Regular representation problem from the area of Algebraic Graph Theory. We present the Cage problem and computational techniques of how to approach it for given specific parameters. We describe our computational approach to the Regular representation problem of k-uniform hypergraphs for groups of order smaller than 33 with our published results.