检索结果-内蒙古大学图书馆

Financial Fraud Detection: A Comparative Study of Quantum Machine Learning Models

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Innan, Nouhaila Khan, Muhammad Al-Zafar Bennai, Mohamed Quantum Physics and Magnetism Team LPMC Faculty of Sciences Ben M'sick Hassan II University of Casablanca Morocco Zaiku Group Ltd Liverpool United Kingdom School of Computer Science and Applied Mathematics University of the Witwatersrand 1 Jan Smuts Ave Braamfontein Johannesburg Gauteng2000 South Africa

In this research, a comparative study of four Quantum Machine Learning (QML) models was conducted for fraud detection in finance. We proved that the Quantum Support Vector Classifier model achieved the highest performance, with F1 scores of 0.98 for fraud and non-fraud classes. Other models like the Variational Quantum Classifier, Estimator Quantum Neural Network (QNN), and Sampler QNN demonstrate promising results, propelling the potential of QML classification for financial applications. While they exhibit certain limitations, the insights attained pave the way for future enhancements and optimisation strategies. However, challenges exist, including the need for more efficient quantum algorithms and larger and more complex datasets. The article provides solutions to overcome current limitations and contributes new insights to the field of Quantum Machine Learning in fraud detection, with important implications for its future development. © 2023, CC BY.

关键词： Finance

Controllable spin filtering and half-metallicity in β12-borophene nanoribbons

学校读者我要写书评

暂无评论

Physical Review B 2021年第24期104卷 245431-245431页

作者： Fahimeh Norouzi Mohsen Farokhnezhad Mahdi Esmaeilzadeh Bartlomiej Szafran Department of Physics Iran University of Science and Technology Narmak Tehran 16844 Iran School of Nano Science Institute for Research in Fundamental Sciences (IPM) Tehran 19395-5531 Iran AGH University of Science and Technology Faculty of Physics and Applied Computer Science al. Mickiewicza 30 30-059 Kraków Poland

The experimental observation of the Dirac fermion states in β12-borophene sheets and the discovery of their novel topological properties have made them a promising candidate for spintronic applications. Here, by combining the nonequilibrium Green's function (NEGF) and tight-binding (TB) approximations, we study the charge and spin transport properties through a β12-borophene nanoribbon (BNR) with different edge shapes. We show that for BNR exposed to a nonlocal exchange magnetic field, the spin filtering occurs so that the spin direction of transmitted electrons could be controlled by adjusting the energy of incoming electrons with the help of an external backgate voltage. It is found that an armchair BNR (ABNR) in the simultaneous presence of a transverse electric field and a nonlocal exchange field acquires half-metallic properties. The influence of local exchange fields is evaluated by exposing the edges of BNRs to ferromagnetic strips with parallel and antiparallel configurations. Our findings show that the edge manipulations in BNRs lead to the emergence of giant magnetoresistance and a perfect spin filter. Finally, we study the effects of edge vacancies and Anderson disorder on the spin-dependent conductance of an ABNR and find that the perfect spin polarization is not destroyed in the presence of Anderson disorder and various single vacancies. Our results reveal the outstanding spin transport properties of ABNRs for future spintronic devices.

关键词： Spin filtering Spintronics Nanoribbon Green's function methods Tight-binding model

Versatile tape-drive target for high-repetition-rate laser-driven proton acceleration

学校读者我要写书评

暂无评论

High Power Laser science and Engineering 2023年第4期11卷 59-69页

作者： N.Xu M.J.V.Streeter O.C.Ettlinger H.Ahmed S.Astbury M.Borghesi N.Bourgeois C.B.Curry S.J.D.Dann N.P.Dover T.Dzelzainis V.Istokskaia M.Gauthier L.Giuffrida G.D.Glenn S.H.Glenzer R.J.Gray J.S.Green G.S.Hicks C.Hyland M.King B.Loughran D.Margarone O.McCusker P.McKenna C.Parisuaña P.Parsons C.Spindloe D.R.Symes F.Treffert C.A.J.Palmer Z.Najmudin John Adams Institute for Accelerator Science Blackett LaboratoryImperial College LondonLondonUK School of Maths and Physics Queen’s University BelfastBelfastUK Central Laser Facility STFC Rutherford Appleton LaboratoryDidcotUK SLAC National Accelerator Laboratory Menlo ParkUSA ELI Beamlines Centre Institute of PhysicsCASDolni BrezanyCzech Republic Faculty of Nuclear Sciences and Physical Engineering Czech Technical University in PraguePragueCzech Republic Department of Physics SUPAUniversity of StrathclydeGlasgowUK Department of Mechanical Engineering Stanford UniversityStanfordUSA Department of Applied Physics Stanford UniversityStanfordUSA Department of Electrical and Computer Engineering University of AlbertaEdmontonCanada Institut für Kernphysik Technische Universität DarmstadtDarmstadtGermany

We present the development and characterization of a high-stability,multi-material,multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 *** tape surface position was measured to be stable on the sub-micrometre scale,compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers(>kHz).Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended *** target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team,with the exception of tape replacement,producing the largest data-set of relativistically intense laser–solid foil measurements to *** tape drive provides robust targetry for the generation and study of high-repetitionrate ion beams using next-generation high-power laser systems,also enabling wider applications of laser-driven proton sources.

关键词： high-repetition-rate laser target laser-plasma acceleration proton generation tape-drive target

Quantum analog of Landau-Lifshitz-Gilbert dynamics

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Liu, Yuefei Miranda, Ivan P. Johnson, Lee Bergman, Anders Delin, Anna Thonig, Danny Pereiro, Manuel Eriksson, Olle Azimi-Mousolou, Vahid Sjöqvist, Erik Department of Applied Physics School of Engineering Sciences KTH Royal Institute of Technology AlbaNova University Center StockholmSE-10691 Sweden Department of Physics and Astronomy Uppsala University Box 516 UppsalaSE-751 20 Sweden Department of Physics and Electrical Engineering Linnaeus University KalmarSE-39231 Sweden KTH Royal Institute of Technology StockholmSE-10044 Sweden KTH Royal Institute of Technology StockholmSE-10044 Sweden School of Science and Technology Örebro University ÖrebroSE-701 82 Sweden WISE-Wallenberg Initiative Materials Science Uppsala University Box 516 UppsalaSE-751 20 Sweden Department of Applied Mathematics and Computer Science Faculty of Mathematics and Statistics University of Isfahan Isfahan81746-73441 Iran

The Landau-Lifshitz-Gilbert (LLG) and Landau-Lifshitz (LL) equations play an essential role for describing the dynamics of magnetization in solids. While a quantum analog of the LL dynamics has been proposed in [Phys. Rev. Lett. 110, 147201 (2013)], the corresponding quantum version of LLG remains unknown. Here, we propose such a quantum LLG equation that inherently conserves purity of the quantum state. We examine the quantum LLG dynamics of a dimer consisting of two interacting spin- 12 particles. Our analysis reveals that, in the case of ferromagnetic coupling, the evolution of initially uncorrelated spins mirrors the classical LLG dynamics. However, in the antiferromagnetic scenario, we observe pronounced deviations from classical behavior, underscoring the unique dynamics of becoming a spinless state, which is non-locally correlated. Moreover, when considering spins that are initially entangled, our study uncovers an unusual form of revival-type quantum correlation dynamics, which differs significantly from what is typically seen in open quantum systems. Copyright © 2024, The Authors. All rights reserved.

关键词： Quantum entanglement

Invariants and reversibility in polynomial systems of ODEs

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Grašič, Mateja Jarrah, Abdul Salam Romanovski, Valery G. Faculty of Natural Science and Mathematics University of Maribor Koroška cesta 160 MariborSI-2000 Slovenia Institute of Mathematics Physics and Mechanics Jadranska 19 LjubljanaSI-1000 Slovenia Department of Mathematics and Statistics American University of Sharjah Sharjah United Arab Emirates Faculty of Electrical Engineering and Computer Science University of Maribor Koroška cesta 46 MariborSI-2000 Slovenia Center for Applied Mathematics and Theoretical Physics Mladinska 3 MariborSI-2000 Slovenia

This paper explores a relationship between invariants of certain group actions and the time-reversibility of two-dimensional polynomial differential systems exhibiting a 1: −1 resonant singularity at the origin. We focus on the connection of time-reversibility with the Sibirsky subvariety of the center (integrability) variety, which encompasses systems possessing a local analytic first integral near the origin. An algorithm for generating the Sibirsky ideal for these systems is proposed and the algebraic properties of the ideal are examined. Furthermore, using a generalization of the concept of time-reversibility we study n-dimensional systems with a 1: ζ: ζ2 : ···: ζn−1 resonant singularity at the origin, where n is prime and ζ is a primitive n-th root of unity. We study the invariants of a Lie group action on the parameter space of the system, leveraging the theory of binomial ideals as a fundamental tool for the analysis. Our study reveals intriguing connections between generalized reversibility, invariants, and binomial ideals, shedding light on their complex interrelations. © 2023, CC BY.

关键词： Polynomials

Bayesian multi-exposure image fusion for robust high dynamic range ptychography

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Kodgirwar, Shantanu Loetgering, Lars Liu, Chang Joseph, Aleena Licht, Leona Penagos Molina, Daniel S. Eschen, Wilhelm Rothhardt, Jan Habeck, Michael Faculty of Medicine University of Jena Jena07743 Germany ZEISS Research Microscopy Solutions Jena07745 Germany Helmholtz-Institute Jena Jena07743 Germany GSI Helmholtzzentrum für Schwerionenforschung Darmstadt64291 Germany Institute of Applied Physics Abbe Center of Photonics University of Jena Jena07745 Germany Fraunhofer Institute for Applied Optics and Precision Engineering Jena07745 Germany Faculty of Mathematics and Computer Science University of Jena Jena07743 Germany Max Planck Institute for Multidisciplinary Sciences Goettingen37077 Germany

The limited dynamic range of the detector can impede coherent diffractive imaging (CDI) schemes from achieving diffraction-limited resolution. To overcome this limitation, a straightforward approach is to utilize high dynamic range (HDR) imaging through multi-exposure image fusion (MEF). This method involves capturing measurements at different exposure times, spanning from under to overexposure and fusing them into a single HDR image. The conventional MEF technique in ptychography typically involves subtracting the background noise, ignoring the saturated pixels and then merging the acquisitions. However, this approach is inadequate under conditions of low signal-to-noise ratio (SNR). Additionally, variations in illumination intensity significantly affect the phase retrieval process. To address these issues, we propose a Bayesian MEF modeling approach based on a modified Poisson distribution that takes the background and saturation into account. To infer the model parameters, the expectation-maximization (EM) algorithm is employed. As demonstrated with synthetic and experimental data, our approach outperforms the conventional MEF method, offering superior phase retrieval under challenging experimental conditions. This work underscores the significance of robust multi-exposure image fusion for ptychography, particularly in imaging shot-noise-dominated weakly scattering specimens or in cases where access to HDR detectors with high SNR is limited. Furthermore, the applicability of the Bayesian MEF approach extends beyond CDI to any imaging scheme that requires HDR treatment. Given this versatility, we provide the implementation of our algorithm as a Python package. © 2024, CC BY.

关键词： Image fusion

Discrete symmetries tested at 10−4 precision using linear polarization of photons from positronium annihilations

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Moskal, Pawel Czerwiński, Eryk Raj, Juhi Bass, Steven D. Beyene, Ermias Y. Chug, Neha Coussat, Aurélien Curceanu, Catalina Dadgar, Meysam Das, Manish Dulski, Kamil Gajos, Aleksander Gorgol, Marek Hiesmayr, Beatrix C. Jasińska, Bozena Kacprzak, Krzysztof Kaplanoglu, Tevfik Kaplon, Lukasz Klimaszewski, Konrad Konieczka, Pawel Korcyl, Grzegorz Kozik, Tomasz Krzemien, Wojciech Kumar, Deepak Moyo, Simbarashe Mryka, Wiktor Niedźwiecki, Szymon Parzych, Szymon del Río, Elena Pérez Raczyński, Lech Sharma, Sushil Choudhary, Shivani Shopa, Roman Y. Silarski, Michal Skurzok, Magdalena Stępien, Ewa L. Tanty, Pooja Ardebili, Faranak Tayefi Ardebili, Keyvan Tayefi Eliyan, Kavya Valsan Wiślicki, Wojciech Marian Smoluchowski Institute of Physics Jagiellonian University Kraków Poland Centre for Theranostics Jagiellonian University Kraków Poland Kitzbühel Centre for Physics Kitzbühel Austria INFN Laboratori Nazionali di Frascati Frascati Italy Institute of Physics Maria Curie-Sklodowska University Lublin Poland Faculty of Physics University of Vienna Vienna Austria Department of Complex Systems National Centre for Nuclear Research Otwock-Świerk Poland Institute of Applied Computer Science Jagiellonian University Kraków Poland High Energy Physics Division National Centre for Nuclear Research Otwock-Świerk Poland

Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of 10−4 signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation. © 2024, CC BY.

关键词： Photons

A Ready-to-Use Beam Steering Application Using a 3D-Printed System Integrated with a Dielectric Lens and Ultra-Wideband Antenna

学校读者我要写书评

暂无评论

A Ready-to-Use Beam Steering Application Using a 3D-Printed ...

International Technical Conference o Circuits/Systems, computers and Communications (ITC-CSCC)

作者： Patchadaporn Sangpet Virote Pirajnanchai Suramate Chalermwisutkul Nonchanutt Chudpooti Deparment of Electrical and Computer Engineering Faculty of Engineering King Mongkut's University of Technology North Bangkok Bangkok Thailand Deparment of Electronics and Telecommunication Engineering Faculty of Engineering Rajamangala University of Technology Thanyaburi Pathum Thani Thailand The Sirindhorn International Thai-German Graduate School of Engineering King Mongkut's University of Technology North Bangkok Bangkok Thailand Deparment of Industrial Physics and Medical Instrumentation Faculty of Applied Science King Mongkut's University of Technology North Bangkok Bangkok Thailand

ISBN: (数字)9798350379051

ISBN: (纸本)9798350379068

The study introduces a 3D-printed lens assembly that has been rotated and equipped with an ultrawideband (UWB) antenna, designed specifically for beam-steering applications. The primary objective is to achieve beam steering by integrating the rotating 3D-printed lens assembly with a hemispherical lens and UWB antenna. The UWB antenna is constructed on an FR-4 substrate, while the hemispherical lens and the rotating 3D-printed lens assembly are composed of Acrylonitrile Butadiene Styrene (ABS). To allow the hemispherical lens to rotate to a certain angle, a collection of 3D-printed lenses that can be rotated was created. These lenses were marked with five predetermined angles: 300 degrees, 330 degrees, 0 degrees, 30 degrees, and 60 degrees. Both the modeling and experimental findings demonstrate that the UWB antenna with the 3D-printed rotatable hemispherical lens assembly is unable to guide the beam at a low frequency of 3.1 GHz. Nevertheless, at frequencies of 7.0 GHz and 10.6 GHz for intermediate and high frequencies, respectively, the beam can be directed based on the rotation of the hemispherical lens.

关键词： computers Beam steering Ultra wideband antennas Frequency measurement Dielectrics High frequency Assembly

DATASET OF FLUORESCENCE SPECTRA AND CHEMICAL PARAMETERS OF OLIVE OILS

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Venturini, Francesca Sperti, Michela Michelucci, Umberto Gucciardi, Arnaud Martos, Vanessa M. Deriu, Marco A. Institute of Applied Mathematics and Physics Zurich University of Applied Sciences Winterthur Switzerland Artificial Intelligence Research and Development TOELT LLC Switzerland PolitoBIOMed Lab Department of Mechanical Aerospace Engineering Politecnico di Torino Turin Italy Computer Science Department Lucerne University of Applied Sciences and Arts Lucerne Switzerland Artificial Intelligence Laboratory University of Ljubljana Ljubljana Slovenia Department of Plant Physiology Faculty of Sciences Biotechnology Institute University of Granada Spain

This dataset encompasses fluorescence spectra and chemical parameters of 24 olive oil samples from the 2019–2020 harvest provided by the producer Conde de Benalúa, Granada, Spain. The oils are characterized by different qualities: 10 extra virgin olive oil (EVOO), 8 virgin olive oil (VOO), and 6 lampante olive oil (LOO) samples. For each sample, the dataset includes fluorescence spectra obtained with two excitation wavelengths, oil quality, and five chemical parameters necessary for the quality assessment of olive oil. The fluorescence spectra were obtained by exciting the samples at 365 nm and 395 nm under identical conditions. The dataset includes the values of the following chemical parameters for each olive oil sample: acidity, peroxide value, K270, K232, ethyl esters, and the quality of the samples (EVOO, VOO, or LOO). The dataset offers a unique possibility for researchers in food technology to develop machine learning models based on fluorescence data for the quality assessment of olive oil due to the availability of both spectroscopic and chemical data. The dataset can be used, for example, to predict one or multiple chemical parameters or to classify samples based on their quality from fluorescence spectra. © 2023, CC BY-NC-ND.

关键词： Fluorescence