Wydział Nauk Ścisłych i Przyrodniczych / Faculty of Exact and Natural Sciences
http://hdl.handle.net/11331/16
Sun, 19 Sep 2021 17:42:10 GMT2021-09-19T17:42:10ZOn the locally polynomial complexity of the projection-gradient method for solving piecewise quadratic optimisation problems
http://hdl.handle.net/11331/3614
On the locally polynomial complexity of the projection-gradient method for solving piecewise quadratic optimisation problems
Prusińska, Agnieszka; Szkatuła, Krzysztof; Tret’yakov, Alexey
This paper proposes a method for solving optimisation problems involving piecewise quadratic functions. The method provides a solution in a finite number of iterations, and the computational complexity of the proposed method is locally polynomial of the problem dimension, i.e., if the initial point belongs to the sufficiently small neighbourhood of the solution set. Proposed method could be applied for solving large systems of linear inequalities
Fri, 01 Jan 2021 00:00:00 GMThttp://hdl.handle.net/11331/36142021-01-01T00:00:00ZContinuous dependence of the singular nonlinear Van der Pol equation solutions with respect to the boundary conditions: elements of p-regularity theory
http://hdl.handle.net/11331/3613
Continuous dependence of the singular nonlinear Van der Pol equation solutions with respect to the boundary conditions: elements of p-regularity theory
Medak, Beata; Tret’yakov, Alexey
This paper studies the problem of the continuous dependence of Van der Pol equation solutions with respect to the boundary conditions. We provide a new approach for the existence of such solutions via p-regularity theory. Several existence theorems about continuous solutions are established
Fri, 01 Jan 2021 00:00:00 GMThttp://hdl.handle.net/11331/36132021-01-01T00:00:00ZOn Raman optical activity sign-switching between the ground and excited states leading to an unusual resonance ROA induced chirality
http://hdl.handle.net/11331/3612
On Raman optical activity sign-switching between the ground and excited states leading to an unusual resonance ROA induced chirality
Machalska, Ewa; Zając, Grzegorz; Barańska, Małgorzata; Kaczorek, Dorota; Kawęcki, Robert; Lipiński, Piotr F. J.; Rode, Joanna E.; Dobrowolska, Jan Cz.
Raman optical activity (ROA) spectra recorded for a chiral naphthalene diimide derivative (nBu-NDI–BINAM) dissolved in a series of solvents exhibit strong solute to solvent induced chirality with: (1) dominating bands of solvents, (2) nBu-NDI–BINAM resonance ROA (RROA) bands which are barely visible, (3) monosignate RROA Solvent spectra with an unexpected sign concordant with that of the ECD band of the resonant electronic state, (4) bisignate RROA bands for a few solvents, and (5) superposition of non-resonant and resonant ROA bands of the chiral solvents. The unusual ROA enhancement was explained in terms of resonance energy transfer with resonant Raman emission. The surprising RROA sign-switching was found to be due to specific conformational equilibria where one solute conformer dominates in the ground and the other in the first excited singlet state, and, the signs of the related ECD bands of these two conformers are opposite
Fri, 01 Jan 2021 00:00:00 GMThttp://hdl.handle.net/11331/36122021-01-01T00:00:00ZEvaluating the relationship between strong geomagnetic storms and electric grid failures in Poland using the geoelectric field as a GIC proxy
http://hdl.handle.net/11331/3611
Evaluating the relationship between strong geomagnetic storms and electric grid failures in Poland using the geoelectric field as a GIC proxy
Gil, Agnieszka; Berendt-Marchel, Monika; Modzelewska, Renata; Moskwa, Szczepan; Siłuszyk, Agnieszka; Siłuszyk, Marek; Tomaszek, Łukasz; Wawrzaszek, Anna; Wawrzyńczak, Anna
We study intense geomagnetic storms (Dst < −100nT) during the first half of the solar cycle 24. This type of storm appeared only a few times, mostly associated with southwardly directed heliospheric magnetic field Bz. Using various methods such as self-organizing maps, statistical and superposed epoch analysis, we show that during and right after intense geomagnetic storms, there is growth in the number of transmission line failures. We also examine the temporal changes in the number of failures during 2010-2014 and find that the growing linear tendency of electrical grid failure occurrence is possibly connected with solar activity. We compare these results with the geoelectric field calculated for the region of Poland using a 1-D layered conductivity Earth model
Fri, 01 Jan 2021 00:00:00 GMThttp://hdl.handle.net/11331/36112021-01-01T00:00:00Z