检索结果-内蒙古大学图书馆

Perfect cycles in the synchronous Heider dynamics in complete network

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Burda, Zdzislaw Krawczyk, Malgorzata J. Kulakowski, Krzysztof AGH University Of Science And Technology Faculty Of Physics And Applied Computer Science al. Mickiewicza 30 Kraków30-059 Poland

We discuss a cellular automaton simulating the process of reaching Heider balance in a fully connected network. The dynamics of the automaton is defined by a deterministic, synchronous and global update rule. The dynamics has a very rich spectrum of attractors including fixed points and limit cycles, the length and number of which change with the size of the system. In this paper we concentrate on a class of limit cycles that preserve energy spectrum of the consecutive states. We call such limit cycles perfect. Consecutive states in a perfect cycle are separated from each other by the same Hamming distance. Also the Hamming distance between any two states separated by k steps in a perfect cycle is the same for all such pairs of states. The states of a perfect cycle form a very symmetric trajectory in the configuration space. We argue that the symmetry of the trajectories is rooted in the permutation symmetry of vertices of the network and a local symmetry of a certain energy function measuring the level of balance/frustration of triads. © 2022, CC BY.

关键词： Dynamics

Aharonov-Bohm oscillations in phosphorene quantum rings: mass anisotropy compensation by confinement potential

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Thakur, Tanmay Szafran, Bartlomiej AGH University of Science and Technology Faculty of Physics and Applied Computer Science al. Mickiewicza 30 Kraków30-059 Poland

We consider the Aharonov-Bohm (AB) effect on a confined electron ground state in a quantum ring defined electrostatically within the phosphorene monolayer. The strong anisotropy of effective masses in phosphorene quenches ground-state oscillations for a circular ring because of interrupted persistent current circulation around the ring. An elliptic deformation of the confinement potential can compensate for the anisotropy of the effective masses and produce ground-state parity transformations with the AB periodicity. Moreover, a specific ratio of the semiaxes is determined for which the spectrum becomes identical to that of a circular quantum ring and an isotropic effective mass. We identify a generalized angular momentum operator which commutes with the continuum Hamiltonian for the chosen ratio of the semi-axes that closes the avoided crossings of energy levels for states of the same parity and spin. Ground-state oscillations for the two-electron ground state are also discussed. © 2022, CC BY.

关键词： Ground state

Exciton localization on p-i-n junctions in two-dimensional crystals

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Szafran, Bartlomiej AGH University of Science and Technology Faculty of Physics and Applied Computer Science al. Mickiewicza 30 Kraków30-059 Poland

We consider a neutral exciton localized on a model p-i-n junction defined in a two-dimensional crystal: MoSe2 and phosphorene, using a variational approach to the effective mass Hamiltonian. The variational solution to the problem with non-separable center of mass provides the exciton density in the real space and accounts for the kinetic energy due to the exciton localization. For low values of the potential step across the junction, the exciton occupies an area which is much larger than the nominal width of the junction. Localization of the exciton within the junction area is accompanied by the appearance of the dipole moment induced by the local electric field. The induced dipole moment becomes a linear function of the potential step only when the step is sufficiently large. In consequence, the energy dependence on the step value is non-parabolic. We demonstrate that the exciton gets localized not exactly at the center of the junction but on the side which is more energetically favourable for the heavier carrier: electron or hole. © 2022, CC BY.

关键词： Excitons

Status achieved in an organization - rank dynamics

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Woloszyn, Maciej Kulakowski, Krzysztof AGH University of Science and Technology Faculty of Physics and Applied Computer Science al. Mickiewicza 30 Kraków30-059 Poland

A new model of an evolution of ranks of employees due to staff turnover in an organization is designed. If the rank is determined only by the performance, the rank shift of incumbents due to the turnover is proportional to the initial rank: the status of high staff is reduced only slightly. This effect that has been observed in the literature. However, if the status also depends on some other variable, the positions of high staff may be greatly deteriorated. In that case, the effect depends nonlinearly on the time τ between subsequent replacements of staff. © 2022, CC BY-NC-ND.

关键词：

Almost optimal manipulation of a pair of alternatives

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Szybowski, Jacek Kulakowski, Konrad Ernst, Sebastian AGH University of Science and Technology The Faculty of Applied Mathematics al. Mickiewicza 30 Krakow30-059 Poland AGH University of Science and Technology The Department of Applied Computer Science Al. Adama Mickiewicza 30 Krakow30-059 Poland

The role of an expert in the decision-making process is crucial, as the final recommendation depends on his disposition, clarity of mind, experience, and knowledge of the problem. However, the recommendation also depends on their honesty. But what if the expert is dishonest? Then, the answer on how difficult it is to manipulate in a given case becomes essential. In the presented work, we consider manipulation of a ranking obtained by comparing alternatives in pairs. More specifically, we propose an algorithm for finding an almost optimal way to swap the positions of two selected alternatives. Thanks to this, it is possible to determine how difficult such manipulation is in a given case. Theoretical considerations are illustrated by a practical example. Copyright © 2023, The Authors. All rights reserved.

关键词： Decision making

Symmetric cumulant sc2,4{4} and asymmetric cumulant ac2{3} from transverse momentum conservation and flow

学校读者我要写书评

暂无评论

Physical Review C 2024年第2期110卷 024901-024901页

作者： Jia-Lin Pei (裴家琳) Guo-Liang Ma (马国亮) Adam Bzdak Key Laboratory of Nuclear Physics and Ion-beam Application (MOE) Institute of Modern Physics Shanghai Research Center for Theoretical Nuclear Physics NSFC and Faculty of Physics and Applied Computer Science 30-059 Kraków Poland

Multiparticle cumulants method can be used to reveal long-range collectivity in small and large colliding systems. The four-particle symmetric cumulant sc2,4{4}, three-particle asymmetric cumulant ac2{3}, and the normalized cumulants nsc2,4{4} and nac2{3} from the transverse momentum conservation and flow are calculated. The interplay between the two effects is also investigated. Our results are in a good agreement with the recent ATLAS measurements of multiparticle azimuthal correlations with the subevent cumulant method, which provides insight into the origin of collective flow in small systems.

关键词： Collective flow Particle correlations & fluctuations Quark-gluon plasma Relativistic heavy-ion collisions

Improving DL-Learner on a Malware Detection Use Case 36

学校读者我要写书评

暂无评论

Improving DL-Learner on a Malware Detection Use Case

36th International Workshop on Description Logics, DL 2023

作者： Bisták, Tomáš Švec, Peter Kluka, Ján Šimko, Alexander Balogh, Štefan Homola, Martin Department of Applied Informatics Faculty of Mathematics Physics and Informatics Comenius University Mlynská dolina Bratislava842 48 Slovakia Institute of Computer Science and Mathematics Faculty of Electrical Engineering and Information Technology Slovak University of Technology Ilkovicova 3 Bratislava812 19 Slovakia

Automation of malware characterization has become increasingly important for early malware detection over the past decades. Since it is crucial to be able to perform malware detection transparently, explainable machine-learning methods may be considered particularly suitable for this application. In our previous work, we thus employed algorithms for learning description-logics concept expressions to obtain structured characterizations of malicious software. The results of our initial experiments, however, lead us to several inconsistencies in the behaviour of the studied algorithms included in DL-Learner, a widely adopted framework for concept learning. Hence, in this work, we make a couple of corrections to DL-Learner, along with a few further enhancements, and repeat the experiments to empirically assess the effects of our changes. The outcomes show that the modified algorithms can mark an improvement in terms of the predictability of their behaviour as well as evaluation metrics. © 2023 CEUR-WS. All rights reserved.

关键词： Malware

Composite metamorphic relations for integration testing 22

学校读者我要写书评

暂无评论

Composite metamorphic relations for integration testing

8th International Conference on computer Technology Applications, ICCTA 2022

作者： Iakusheva, Sofia Khritankov, Anton Phystech School of Applied Mathematics and Informatics Moscow Institute of Physics and Technology Russia Faculty of Computer Science Dept. of Software Engineering Hse University Russia

ISBN: (纸本)9781450396226

Metamorphic testing is a testing method for problems without test oracles. Integration testing allows for detecting errors in complex systems that may not be found during the testing of their components. In this paper, we propose a novel approach that applies metamorphic testing in integration testing. The main idea is to develop a composite metamorphic relation for the system represented as an acyclic graph. This relation is a logical function of metamorphic relations for the parts of the system (vertices of the graph). It takes into account the features of the parts. Also, it can simplify the search for failure by identifying the subsystem with error. In this paper's theoretical part, we describe an algorithm of relation design. Then, we apply our method to a bioinformatics system for comparative genetic analysis of tissues using production tools. This experiment proves our method can be applied to real-life pipelines and find errors in them. © 2022 ACM.

关键词： Integration testing

Insights into electronic and transport properties of phosphorene nanorings in two perpendicular directions: Effects of circular and elliptical external potentials

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Bazrafshan, M. Amir Khoeini, Farhad Szafran, Bartlomiej Department of Physics University of Zanjan P.O. Box 45195-313 Zanjan Iran Faculty of Physics and Applied Computer Science AGH University of Science and Technology al. Mickiewicza 30 Kraków30-059 Poland

In this work, we study the electronic and transport properties of phosphorene nanorings in two perpendicular directions (zigzag and armchair directions) in the presence of zigzag metallic source and drain leads. Our results are based on the non-equilibrium Green's function (NEGF) method and a five-parameter tight-binding (TB) approach. We investigate how system parameters affect the electronic transport. These parameters include the radius of the rings, the width of the leads and the external potential. Our results show that for all configurations studied, a transport energy gap exists whose width can be tuned by the width of the leads and the radius of the nanoring. The transmission function of wider leads shows more sensitivity to the variation of the inner radius due to higher electronic states that can respond to smaller changes in the scattering region. In addition, the transport along the armchair direction is more susceptible to tuning than the transport along the zigzag direction. The effects of external potentials on the conductance are more pronounced than the geometrical parameters. In particular the circular potential of the amplitude of 0.1 eV can widen the transport gap by about ~0.35 eV. © 2023, CC BY.

关键词： Nanorings