https://uniba.sk/ Najnovšie novinky sk https://uniba.sk/fileadmin/tt_news_article.gif https://uniba.sk/ Najnovšie novinky TYPO3 - get.content.right http://blogs.law.harvard.edu/tech/rss Thu, 31 Dec 2026 00:00:00 +0100 https://uniba.sk/ Scientists from Comenius University won in two categories at this year's ESET Science Award. Igor... More information about the laureates Interview with Igor Farkaš ]]> [RUK] Titulka - úzke novinky [RUK][SP] Aktuality Osobnosti pr@uniba.sk Mon, 21 Oct 2024 12:41:00 +0200 https://uniba.sk/ Thursday 10.10.2024 at 9:50, Lecture room M 213 Lukáš Gáborík:
Chebyshev and Manhattan nowhere-zero flows
Abstract:
The area of nowhere-zero flows has been widely researched since its introduction by Tutte in 1954, when he also conjectured that each bridgeless graph has a nowhere-zero 5-flow. Recently, Mattiolo et al. researched real-valued nowhere-zero flows in two dimensions. They found some interesting properties (as rationality), in which 1D and 2D flows differ. We examine whether one can achieve better consistency by changing the considered norm from the Euclidean to the Chebyshev or the Manhattan one. In the two-dimensional case, we prove a one-to-one correspondence between Chebyshev and Manhattan flows, characterise graphs with unit vector flows and find some bounds on the flow number. Moreover, we observe a structure whose existence implies a 1D 5-flow and a 2D 2.5-flow, which opens a new possible way to prove Tutte's 5-flow conjecture. This is joint work with Sascha Kurz, Giuseppe Mazzuoccolo, Jozef Rajník, Florian Rieg and Gloria Tabarelli. More information]]> [FMFI] Prednášky a semináre [FMFI] Kalendár Martin.Skoviera@fmph.uniba.sk Mon, 07 Oct 2024 15:35:00 +0200 http://https://www.fm.uniba.sk/en/partnership/the-taiwan-studies-center-in-bratislava/events/ [FM] Kalendár Mon, 07 Oct 2024 14:27:00 +0200 https://uniba.sk/ [JLF] Titulka - slider Sun, 06 Oct 2024 15:34:00 +0200 https://uniba.sk/ The New Head of the International Relations Department at RUK Begins Faculty Tour He also aims to become more familiar with the environment and specifics of each faculty. The meetings take place in a friendly and relaxed atmosphere, fostering open dialogue and an innovative approach to international cooperation. We look forward to innovative approaches and a new phase of collaboration!

]]> [FM] Titulka - úzke novinky Fri, 04 Oct 2024 13:01:00 +0200 https://uniba.sk/ Thursday 10.10.2024 at 14:00, Lecture room M 223 Tatiana Kossaczká:
Deep Learning Enhanced Numerical Schemes
Abstract: 
In this talk, the enhancement of numerical schemes using deep learning is addressed. In the first part, a Deep Finite Difference Method is proposed to improve standard finite difference methods for solving partial differential equations by approximating the local truncation error. Higher numerical accuracy is achieved in one- and two-dimensional examples without compromising consistency and convergence. In the second part, the fifth-order Weighted Essentially Non-Oscillatory (WENO) shock capturing scheme is improved by using a neural network to adjust the smoothness indicators, leading to increased accuracy near shocks. The new method, WENO-DS (Deep Smoothness), eliminates the need for post-processing steps. WENO-DS is shown to consistently outperform the traditional WENO scheme on Buckley-Leverett, Burgers', and Euler equations. The approach is extended to the sixth-order WENO scheme for nonlinear degenerate parabolic equations, where superior performance is demonstrated in benchmark tests. Fifth- and sixth-order accuracy is maintained in both methods and is proved theoretically.]]> [FMFI] Prednášky a semináre [FMFI] Kalendár Pavol.Quittner@fmph.uniba.sk Fri, 04 Oct 2024 10:15:00 +0200 https://uniba.sk/ Wednesday 9.10.2024 at 14:00, Lecture room F1/364 Dr. Mohammad Alem Sultani:
Machine Learning Approaches for Analyzing Factors Influencing Atmospheric Radon Variability in Bratislava, Slovakia
Abstract:
Radon (²²²Rn) is a radioactive noble gas that is produced in the decay chain of uranium-238 (²³⁸U). The study of outdoor radon is of interest due to its significant contribution to background radiation and its potential use as a tracer in atmospheric research. A variety of factors, including the radon exhalation rate, atmospheric mixing height, and meteorological conditions, contribute to the variability of radon activity concentration (RAC). This study examines the temporal fluctuations in RAC and the factors contributing to its variability in Bratislava, Slovakia, utilizing a four-year dataset of continuous measurements. The hourly, diurnal, and seasonal fluctuations of RAC were subjected to analysis and discussion. Furthermore, machine learning techniques, including artificial neural networks, automatic linear modeling, and random forest, were utilized in conjunction with conventional multivariate linear regression to investigate the factors influencing RAC variability. The analysis revealed that the primary factors affecting RAC are mixing height, radon flux, and temperature. Furthermore, the random forest exhibited superior performance compared to other approaches. This research contributes to a more profound understanding of the processes that shape the atmospheric dynamics of radon.]]> [FMFI] Prednášky a semináre [FMFI] Kalendár Jaroslav.Stanicek@fmph.uniba.sk Thu, 03 Oct 2024 10:56:00 +0200 https://uniba.sk/ From September 26 to 28, the 31st conference of the Slovak Society of Parenteral and Enteral... [JLF] Titulka - úzke novinky milos.hrabovsky@uniba.sk Thu, 03 Oct 2024 10:41:00 +0200 https://uniba.sk/ september 2024 [LF] EN Titulka - široké novinky Thu, 03 Oct 2024 09:22:00 +0200 https://uniba.sk/ Friday 4.10.2024 at 13:15, Lecture room VIII (online too) Eze Leonard Chidiebere:
Theoretical nad Computational Approaches to Determining Sets of Orders of (k,g)-Graphs Abstract:
In this talk, we address the problem of determining the set of possible orders for (k, g)-graphs, which play a fundamental role in the study of the Cage Problem in extremal graph theory. For each pair of parameters k ≥ 3 and g ≥ 3, the complete set of orders of (k, g)-graphs is referred to as the spectrum of orders for the (k, g)-graphs, simply written as (k, g)-spectrum. We integrate theoretical insights with computational techniques to determine both complete and partial spectra of orders for several classes of (k, g)-graphs, including cubic, tetravalent, and pentavalent graphs. Our approach utilizes various construction methods, such as edge and vertex deletion, circulant constructions, and generalized Petersen graphs, to systematically expand the known spectra, particularly for graphs with larger girths. Key results include the successful determination of complete spectra for several parameter sets, as well as notable progress in identifying missing elements in others. We also discuss the challenges associated with determining (k, g)-spectra for higher values of k and g, and propose future directions for extending the study to highly symmetric (k, g)-graphs, such as vertex-transitive and Cayley graphs. [1] L. C. Eze, R. Jajcay and D. Mihalova, An algorithmic approach to determining spectra of orders of (k, g)-graphs, ITAT 2023 Proceedings, CEUR Workshop Proceedings Vol. 3498 (2023) 204 - 208
[2] R. Jajcay and T. Raiman: Spectra of Orders for k-Regular Graphs of Girth g. Discussiones Mathematicae Graph Theory, 41(4) (2021) 1115–1125. https://doi.org/10.7151/dmgt.2233 Those of you who are not able to attend in person or who are still uncertain about the safety of attending in person are welcome to attend via MS Teams. In either case, we hope to see as many of you as possible (either in person or virtually) at our Friday gatherings. ]]> [FMFI] Prednášky a semináre [FMFI] Kalendár Martin.Macaj@fmph.uniba.sk Wed, 02 Oct 2024 15:39:00 +0200