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Vanishing opinions in Latané model of opinion formation

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arXiv 2022年

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

In this paper, the results of computer simulations based on Nowak–Szamrej–Latané model with multiple (from two to five) opinions available in the system are presented. We introduce the noise discrimination level (which says how small the clusters of agents could be considered as negligible) as a quite useful quantity that allows qualitative characterization of the system. We show that depending on the introduced noise discrimination level, the range of actors’ interactions (controlled indirectly by an exponent in distance scaling function, the larger the exponent the more influential the nearest neighbors are) and the information noise level (modeled as social temperature, which increases results in increase of randomness in taking the opinion by the agents), the ultimate number of the opinions (measured as the number of clusters of actors sharing the same opinion in clusters greater than the noise discrimination level) may be smaller than the number of opinions available in the system. These are observed in small and large information noise limits but result in either unanimity, or polarization, or randomization of opinions. © 2022, CC BY.

关键词： Random processes

A hybrid optimization approach for securing cloud-based e-health systems

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Multimedia Tools and Applications 2024年第16期84卷 1-36页

作者： Altherwi, Abdulhadi Ahmad, Mohammad Tauheed Alam, Md. Moddassir Mirza, Hidayath Sultana, Nazia Pasha, Amjad Ali Sultana, Nishat Khan, Asif Irshad Alam, Md Mottahir Azim, Rezaul Department of Industrial Engineering College of Engineering and Computer Science Jazan University PO Box. 706 Jazan45142 Saudi Arabia College of Medicine King Khalid University Abha Saudi Arabia Department of Health Information Management and Technology College of Applied Medical Sciences University of Hafr Al-Batin Hafr Al-Batin Saudi Arabia Department of Electrical and Electronic Engineering College of Engineering and Computer Science Jazan University Jazan45142 Saudi Arabia Government Medical College Siddipet Ensanpalli Siddipet District Telangana502114 India Aerospace Engineering Department King Abdulaziz University Jeddah21589 Saudi Arabia Department of Business Administration Applied College Jazan University P. O. Box 706 Jazan45142 Saudi Arabia Department of Computer Science Aligarh Muslim University Uttar Pradesh Aligarh202002 India Department of Electrical and Computer Engineering Faculty of Engineering King Abdulaziz Jeddah21589 Saudi Arabia Department of Physics University of Chittagong Chattogram4331 Bangladesh

In modern healthcare, cloud-based e-health technology offers substantial benefits but faces significant security challenges. Sensitive patient data is vulnerable to cyber threats during transmission and storage, potentially enabling unethical collaboration between healthcare professionals and cloud storage providers. This paper aims to develop a robust security framework that safeguards patient privacy and prevents unauthorized access to sensitive medical information in remote patient health monitoring systems. The study presents an Artificial Hybrid Optimization with an Attribute-Based Encryption (AHO-ABE) model. The model leverages cryptographic techniques and hybrid optimization to enhance data security. Specifically, whale optimization (WO) is used for efficient key generation, while sheep flock optimization (SFO) is employed for continuous network surveillance. Experimental results demonstrate that the AHO-ABE model significantly enhances data security, outperforming existing RPM-MEC, AID, AI-HCS, and IoT-HMS approaches. The model exhibits superior resilience against unauthorized access and data breaches, achieving a 5 ms execution time, 850 kbps throughput, 0.121 mJ energy usage, and 4 s latency. Combining cryptographic techniques with hybrid optimization algorithms, the AHO-ABE model provides a robust framework for safeguarding sensitive medical information. This approach ensures the integrity and confidentiality of patient data in remote healthcare settings, offering an effective solution against high-performance cyber attacks. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2024.

关键词： Diagnosis

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

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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

Does social distancing matter for infectious disease propagation? A SEIR model and Gompertz law based cellular automaton

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arXiv 2022年

作者： Biernacki, Szymon Malarz, Krzysztof AGH University of Science and Technology Faculty of Physics and Applied Computer Science al. Mickiewicza 30 Kraków30-059 Poland

In this paper, we present stochastic synchronous cellular automaton defined on a square lattice. The automaton rules are based on the SEIR (susceptible → exposed → infected → recovered) model with probabilistic parameters gathered from real-world data on human mortality and the characteristics of the SARS-CoV-2 disease. With computer simulations, we show the influence of the radius of the neighborhood on the number of infected and deceased agents in the artificial population. The increase in the radius of the neighborhood favors the spread of the epidemic. However, for a large range of interactions of exposed agents (who neither have symptoms of the disease nor have been diagnosed by appropriate tests), even isolation of infected agents cannot prevent successful disease propagation. This supports aggressive testing against disease as one of the useful strategies to prevent large peaks of infection in the spread of SARS-CoV-2-like disease. © 2022, CC BY.

关键词： Cellular automata

Perfect cycles in the synchronous Heider dynamics in complete network

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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

Photonic Source of Heralded Greenberger-Horne-Zeilinger States

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Physical Review Letters 2024年第13期132卷 130604-130604页

作者： H. Cao L. M. Hansen F. Giorgino L. Carosini P. Zahálka F. Zilk J. C. Loredo P. Walther University of Vienna Faculty of Physics Vienna Center for Quantum Science and Technology (VCQ) 1090 Vienna Austria Christian Doppler Laboratory for Photonic Quantum Computer Faculty of Physics University of Vienna 1090 Vienna Austria

Generating large multiphoton entangled states is of main interest due to enabling universal photonic quantum computing and all-optical quantum repeater nodes. These applications exploit measurement-based quantum computation using cluster states. Remarkably, it was shown that photonic cluster states of arbitrary size can be generated by using feasible heralded linear optics fusion gates that act on heralded three-photon Greenberger-Horne-Zeilinger (GHZ) states as the initial resource state. Thus, the capability of generating heralded GHZ states is of great importance for scaling up photonic quantum computing. Here, we experimentally demonstrate this required building block by reporting a polarisation-encoded heralded GHZ state of three photons, for which we build a high-rate six-photon source (547±2 Hz) from a solid-state quantum emitter and a stable polarization-based interferometer. The detection of three ancillary photons heralds the generation of three-photon GHZ states among the remaining particles with fidelities up to F=0.7278±0.0106. Our results initiate a path for scalable entangling operations using heralded linear-optics implementations.

关键词： Optical quantum information processing Quantum computation Quantum correlations in quantum information Quantum information processing Quantum optics

Ultrafast laser-induced dynamics of non-equilibrium electron spill-out in nanoplasmonic bilayers

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arXiv 2024年

作者： Avdizhiyan, Artur Janus, Weronika Szpytma, Marcin Lezak, Tomasz Przybylski, Marek Chrobak, Maciej Roddatis, Vladimir Stupakiewicz, Andrzej Razdolski, Ilya Faculty of Physics University of Bialystok Bialystok15-245 Poland Faculty of Physics and Applied Computer Science AGH University of Krakow Kraków Poland Academic Centre for Materials and Nanotechnology AGH University of Krakow Kraków Poland Helmholtz Centre Potsdam Telegrafenberg PotsdamD-14473 Germany

Contemporary quantum plasmonics captures subtle corrections to the properties of plasmonic nanoobjects in the equilibrium. Here, we demonstrate non-equiulbrium spill-out redistribution of the electronic density at the ultrafast timescale. As revealed by time-resolved 2D spectroscopy of nanoplasmonic Fe/Au bilayers, an injection of the laser-excited non-thermal electrons induces transient electron spill-out thus changing the plasma frequency. The response of the local electronic density switches the electronic density behaviour from spill-in to strong (an order of magnitude larger) spill-out at the femtosecond timescale. The superdiffusive transport of hot electrons and the lack of a direct laser heating indicate significantly non-thermal origin of the underlying physics. Our results demonstrate an ultrafast and non-thermal way to control surface plasmon dispersion through transient variations of the spatial electron distribution at the nanoscale. These findings expand quantum plasmonics into previously unexplored directions by introducing ultrashort timescales in the non-equilibrium electronic systems. © 2024, CC0.

关键词： Hazardous materials spills

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

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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

Non-equilibrium dynamics of long-range field configurations in the Proca theory and the counterexample to the law of periodic charge oscillations

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arXiv 2025年

作者： Damski, Bogdan Jagiellonian University Faculty of Physics Astronomy and Applied Computer Science Lojasiewicza 11 Kraków30-348 Poland

Long-range field configurations exist in the Proca theory and their non-equilibrium evolution is of interest in this work. General arguments suggest that a charge can be assigned to them and that its evolution is governed by the law of periodic charge oscillations. We discuss an elegant analytically-solvable example of a field configuration in the Proca theory respecting such a law. We also identify a weak point in the aforementioned general arguments, construct the counterexample to the law of periodic charge oscillations in the Proca theory, and comprehensively discuss it. The Gibbs-Wilbraham phenomenon is discussed in the course of these studies. Copyright © 2025, The Authors. All rights reserved.

关键词： Dynamics