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Low-Temperature Carrier Transport in Magnetic Field in Sandwich-Like Graphene/Co Nanoparticles/Graphene Structure

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SSRN

SSRN 2023年

作者： Fedotov, Alexander K. Gumiennik, Uladzislaw E. Fedotova, Julia A. Przewoźnik, Janusz Kapusta, Czeslaw AGH University of Science and Technology Poland Institute for Nuclear Problems Belarusian State University Babrujskaja Str. 11 Minsk220006 Belarus AGH University of Krakow Faculty of Physics and Applied Computer Science Mickiewicza Av. 30 Kraków30-059 Poland

The improved analysis of carrier transport in the single-layer graphene and hybrid structures like graphene/Co nanoparticles (NPs) and graphene/Co NPs/graphene has been conducted. The temperature and magnetic field dependences of the sheet resistance RSq(T, B) and/or conductivity σSq(T, B) has shown the coexistence of negative (NMR) and positive (PMR) contributions in magnetoresistive effect in all the samples under study. The dependences of RSq(T, B) and/or σSq(T, B) were analysed in the framework of some combinations of 5 models relating to quantum corrections (QCs) to Drude conductivity theory and different hopping models for variable range hopping (VRH) regimes. It was shown, in particular, that in the region of NMR effect below 75 K and in fields B © 2023, The Authors. All rights reserved.

关键词： Graphene

Note on the Margolus-Levitin quantum speed limit for arbitrary fidelity

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arXiv 2023年

作者： Andrzejewski, Krzysztof Bolonek-Lason, Katarzyna Kosiński, Piotr Department of Computer Science Faculty of Physics and Applied Informatics University of Lodz 149/153 Pomorska St. Lodz90-236 Poland Department of Statistical Methods Faculty of Economics and Sociology University of Lodz 41/43 Rewolucji 1905 St. Lodz90-214 Poland

For vanishing fidelity between initial and final states two important quantum speed limits, the Mandelstam-Tamm limit (involving energy dispersion) and Margolus-Levitin one (involving excitation energy expectation value) have been derived. While the generalization of the former limit to the case of arbitrary fidelity is straightforward, the relevant generalization of the latter, given in the seminal paper by Giovanetti et al (Phys. Rev. A67 (2003), 052109) was based on the conjectured equality of lower and upper bounds on the right hand side of generalized Margolus-Levitin inequality, verified numerically up to seven digits. Only recently there appear two proofs of the conjecture. We provide below a very elementary new proof, based on the simplest tools from differential calculus. Thus the generalized Margolus-Levitin speed limit can be derived much in the spirit of the original one valid for vanishing fidelity. © 2023, CC BY.

关键词： Differentiation (calculus)

A Neuroimaging ML-Based Framework for Anosmia Grading in Covid-19

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A Neuroimaging ML-Based Framework for Anosmia Grading in Cov...

IEEE International Symposium on Biomedical Imaging

作者： Hossam Magdy Balaha Mayada Elgendy Ahmed Alksas Mohamed Shehata Norah Saleh Alghamdi Fatma Taher Mohammed Ghazal Mahitab Ghoneim Eslam Hamed Fatma Sherif Ahmed Elgarayhi Mohammed Sallah Mohamed Abdelbadie Salem Elsharawy Kamal Harpal Sandhu Ayman El-Baz Department of Bioengineering J.B. Speed School of Engineering University of Louisville Louisville USA Applied Theoretical Physics Research Group Physics Department Faculty of Science Mansoura University Egypt Department of Computer Sciences College of Computer and Information Sciences Princess Nourah Bint Abdulrahman University Saudi Arabia The College of Technological Innovation Zayed University Dubai UAE Electrical Computer and Biomedical Engineering Depatrment Abu Dhabi University UAE Department of Radiology Faculty of Medicine Mansoura University Egypt Otolaryngology Department Faculty of Mediine Mansoura University Egypt Higher Institute of Engineering and Technology Egypt

ISBN: (数字)9798350313338

ISBN: (纸本)9798350313345

SARS-CoV-2 is the cause of the acute respiratory illness COVID-19. In order to identify whether a COVID-19 patient has normal, moderate, or severe anosmia, this study suggests a computer-assisted diagnostic system. It utilizes fluid-attenuated inversion recovery Magnetic Resonance Imaging and Diffusion Tensor Imaging to extract the olfactory nerve’s appearance, morphology, and diffusivity markers. The suggested CAD system consists of the following stages: (1) extract appearance markers, morphology markers, and diffusivity markers, (2) apply markers fusion, and (3) select the most promising classifier as the basis for the decision and the relevant performance indicators. The current work is unique in that it uses an ensemble of the trained, tuned, and improved ML classifiers to identify OB anosmia using majority voting. From the fusion tests using different folds, stacking boosted the weight accuracy, weighted precision, weighted specificity, weighted sensitivity, and weighted F1-score to 85.30%, 80%, 89.50%, 78.90%, and 78.30% respectively. Regarding the various performance criteria, the LGBM outperforms other ML classifiers.

关键词： COVID-19 Neuroimaging Sensitivity Shape Stacking Olfactory Morphology

NOMA-Based Ze-RIS Empowered Backscatter Communication with Energy-Efficient Resource Management

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IEEE Transactions on Communications 2025年

作者： Asif, Muhammad Bao, Xu Ihsan, Asim Khan, Wali Ullah Li, Xingwang Chatzinotas, Symeon Dobre, Octavia A. The School of Computer Science and Communication Engineering Jiangsu University Zhenjiang China The Department of Electrical Engineering University of Cambridge Cambridge United Kingdom University of Luxembourg Luxembourg City1855 Luxembourg The School of Physics and Electronic Information Engineering Henan Polytechnic University the Jiaozuo Key Laboratory of Crow-Sensing Network Jiaozuo454003 China The Department of Electrical and Computer Engineering Faculty of Engineering and Applied Science Memorial University St. John’sNLA1B 3X9 Canada

This manuscript introduces a novel energy-efficient optimization strategy for a zero-energy reconfigurable intelligent reflecting surface (Ze-RIS) supported backscatter communication system employing non-orthogonal multiple access (NOMA). The central objective is to maximize the energy efficiency of the system by optimizing the several key parameters, including the amplitude reflection coefficient of Ze-RIS, the reflection coefficients of the backscatter tags, transmit beamforming at the base station, and passive beamforming at the Ze-RIS node, while incorporating a practical non-linear energy harvesting model both for the Ze-RIS and backscatter nodes. The proposed algorithm addresses the complex non-convex problem through three stages. Firstly, the transmit beamforming vectors are determined by leveraging the semi-definite programming and successive-convex approximation, while handling the rank-1 constraint with the semi-definite relaxation. Secondly, we determine the amplitude reflection coefficient of Ze-RIS by leveraging the monotonicity property of the objective function. Simultaneously, we compute the reflection coefficients of backscatter tags using the Dinkelbach algorithm, Lagrange duality, and the sub-gradient method. Thirdly, we compute passive beamforming using successive-convex approximation and semi-definite programming techniques, achieving a rank-1 solution through the penalty-based method. Finally, the numerical simulations confirm the effectiveness of the proposed approach, demonstrating its superiority over the benchmark competitors with rapid convergence within a few iterations. © 1972-2012 IEEE. All rights reserved.

关键词： Beamforming

List covering of regular multigraphs with semi-edges

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arXiv 2022年

作者： Bok, Jan Fiala, Jiří Jedličková, Nikola Kratochvíl, Jan Rzążewski, Pawel Computer Science Institute Faculty of Mathematics and Physics Charles University Prague Czech Republic Department of Applied Mathematics Faculty of Mathematics and Physics Charles University Prague Czech Republic Warsaw University of Technology Warsaw Poland University of Warsaw Warsaw Poland

In line with the recent development in topological graph theory, we are considering undirected graphs that are allowed to contain multiple edges, loops, and semi-edges. A graph is called simple if it contains no semi-edges, no loops, and no multiple edges. A graph covering projection, also known as a locally bijective homomorphism, is a mapping between vertices and edges of two graphs which preserves incidences and which is a local bijection on the edge-neighborhood of every vertex. This notion stems from topological graph theory, but has also found applications in combinatorics and theoretical computer science. It has been known that for every fixed simple regular graph H of valency greater than 2, deciding if an input graph covers H is NP-complete. Graphs with semi-edges have been considered in this context only recently and only partial results on the complexity of covering such graphs are known so far. In this paper we consider the list version of the problem, called List-H-Cover, where the vertices and edges of the input graph come with lists of admissible targets. Our main result reads that the List-H-Cover problem is NP-complete for every regular graph H of valency greater than 2 which contains at least one semi-simple vertex (i.e., a vertex which is incident with no loops, with no multiple edges and with at most one semi-edge). Using this result we show the NP-co/polytime dichotomy for the computational complexity of List-HCover for cubic graphs. Copyright © 2022, The Authors. All rights reserved.

关键词： Undirected graphs

Probabilistic High Dynamic Range Preprocessing for Ptychography

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Probabilistic High Dynamic Range Preprocessing for Ptychogra...

2024 Conference on Lasers and Electro-Optics, CLEO 2024

作者： Kodgirwar, Shantanu Loetgering, Lars Liu, Chang Licht, Leona Joseph, Aleena Penagos, Daniel Santiago Eschen, Wilhelm Rothhardt, Jan Habeck, Michael Faculty of Medicine Friedrich Schiller University Jena Jena07743 Germany Carl Zeiss AG Carl-Zeiss-Promenade 10 Jena07745 Germany Institute of Applied Physics Friedrich Schiller University Jena Albert-Einstein-Strasse 6 Jena07745 Germany Helmholtz-Institute Jena Froebelstieg 3 Jena07743 Germany Fraunhofer IOF Albert-Einstein-Strasse 7 Jena07745 Germany Faculty of Mathematics and Computer Science Friedrich Schiller University Jena Ernst-Abbe-Platz 2 Jena07743 Germany Max Plank Institute for Multidisciplinary Sciences Am Fassberg 11 Goettingen37077 Germany

ISBN: (纸本)9781957171395

Fusing acquisitions by varying exposures, from under to overexposed, yields a high dynamic range image. To enhance resolution, this is often used as a preprocessing step in ptychography. Our proposed probabilistic approach models overexposure while taking into account readout noise, resulting in improved inverse modeling. © Optica Publishing Group 2024, © 2024 The Author(s)

关键词： Inverse problems

Multiparticle azimuthal cumulants from transverse momentum conservation and collective flow

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arXiv 2022年

作者： Xie, Mu-Ting Ma, Guo-Liang Bzdak, Adam Institute of Modern Physics Fudan University Shanghai200433 China Shanghai Research Center for Theoretical Nuclear Physics NSFC Fudan University Shanghai200438 China AGH University of Science and Technology Faculty of Physics and Applied Computer Science Kraków30-059 Poland

We calculate the nth order of 2k-particle azimuthal cumulants cn{2k} based on transverse momentum conservation (TMC) and collective flow vn(n=2,3). We demonstrate that the TMC effect only leads to a nonzero cn{2k} with the sign of (−1)nk and the magnitude inversely proportional to (N − 2k)nk. The interplay between TMC and collective flow can change the signs of c2{4}, c3{2} and c3{4} at some values of multiplicity N, which could provide a good probe to study the onset of collectivity and search for the substructure of proton in small colliding systems. © 2022, CC0.

关键词： Momentum

Effect of symmetry breaking of polarized light sea quarks on the nucleon and nuclear structure functions, and sum rules

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Physical Review C 2023年第3期108卷 035203-035203页

作者： Fatemeh Arbabifar Shahin Atashbar Tehrani Hamzeh Khanpour Department of Physics Education Farhangian University P.O. Box 14665-889 Tehran Iran School of Particles and Accelerators Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5531 Tehran Iran AGH University of Science and Technology Faculty of Physics and Applied Computer Science Al. Mickiewicza 30 30-055 Krakow Poland Department of Physics University of Science and Technology of Mazandaran P.O. Box 48518-78195 Behshahr Iran

In this study, we performed calculations and analyses of the structure functions of polarized nucleons and light nuclei, specifically He3 and H3, using second-order Feynman diagrams. Our investigation focused on two main aspects: First, we examined the symmetry properties of polarized light sea quarks. Second, we conducted a detailed investigation into the impacts of symmetry breaking on the structure functions of both nucleons and nuclei. To achieve this, we utilized the existing polarized parton distribution functions (polarized PDFs) available in the literature. These PDFs were used to calculate and compare the polarized structure functions g1 and g2 of the nuclei. Additionally, we examined and analyzed the Bjorken and Efremov-Leader-Teryaev sum rules by utilizing the moments of the polarized structure functions. The Lorentz color force components, namely FEy,n and FBy,n, were determined using the twist-2, twist-3, and twist-4 matrix elements. When symmetry breaking is applied, it is observed that they have similar magnitudes but opposite signs. Our theoretical predictions for the polarized structure functions of nucleons and light nuclei, taking into account the symmetry breaking of light sea quarks, exhibit better agreement with experimental data.

关键词： Deep inelastic scattering Perturbative QCD Polarization phenomena QCD in nuclear reactions A ≤ 5

Scaling properties of elastic pp cross-section

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arXiv 2024年

作者： Praszalowicz, Michal Baldenegro, Cristian Royon, Christophe Staśto, Anna M. Institute of Theoretical Physics Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University S. Lojasiewicza 11 Kraków30-348 Poland Dipartimento di Fisica Sapienza Universitá di Roma Piazzale Aldo Moro 2 Rome00185 Italy Department of Physics and Astronomy The University of Kansas LawrenceKS66045 United States Department of Physics Penn State University University ParkPA16802 United States

We show that the elastic differential pp cross-section has a unique universal property that the ratio of bump-to-dip position is constant from the energies of the ISR to the LHC. We explore this property to compare Geometric Scaling present at the ISR with the recently proposed scaling law at the LHC. We argue that at the LHC, within present experimental uncertainties, there is fact a family of scaling laws. © 2024, CC BY.

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