cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Turning hazardous volatile matter compounds into fuel by catalytic steam reforming: An evolutionary machine learning approach
Creators: name: Shafizadeh, Alireza
name: Shahbeik, Hossein
name: Nadian, Mohammad Hossein
name: Gupta, Vijai Kumar
name: Nizami, Abdul-Sattar
name: Lam, Su Shiung
name: Peng, Wanxi
name: Pan, Junting
name: Tabatabaei, Meisam
name: Aghbashlo, Mortaza
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Chemical and biomass processing systems release volatile matter compounds into the environment daily. Catalytic reforming can convert these compounds into valuable fuels, but developing stable and efficient catalysts is challenging. Machine learning can handle complex relationships in big data and optimize reaction conditions, making it an effective solution for addressing the mentioned issues. This study is the first to develop a machine-learning-based research framework for modeling, understanding, and optimizing the catalytic steam reforming of volatile matter compounds. Toluene catalytic steam reforming is used as a case study to show how chemical/textural analyses (e.g., X-ray diffraction analysis) can be used to obtain input features for machine learning models. Literature is used to compile a database covering a variety of catalyst characteristics and reaction conditions. The process is thoroughly analyzed, mechanistically discussed, modeled by six machine learning models, and optimized using the particle swarm optimization algorithm. Ensemble machine learning provides the best prediction performance (R2 > 0.976) for toluene conversion and product distribution. The optimal tar conversion (higher than 77.2%) is obtained at temperatures between 637.44 and 725.62 °C, with a steam-to-carbon molar ratio of 5.81-7.15 and a catalyst BET surface area 476.03-638.55 m2/g. The feature importance analysis satisfactorily reveals the effects of input descriptors on model prediction. Operating conditions (50.9%) and catalyst properties (49.1%) are equally important in modeling. The developed framework can expedite the search for optimal catalyst characteristics and reaction conditions, not only for catalytic chemical processing but also for related research areas.
MPEC 2023-R160 : 2023 RR5
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 RR5

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Design of a heterogeneous mechanical test using a nonlinear topology optimization approach
Creators: name: Gonçalves, M.
name: Thuillier, Sandrine
name: Andrade-Campos, António
Publisher: name: Zenodo
Year: 2022

description: The design of sheet metal forming parts is increasingly taking advantage of virtual manufacturing tools. An accurate reproduction of the material behavior is required to guarantee the quality of the results. The actual material characterization process requires the use of several classical mechanical tests to extract all the information about the material behavior. To improve this time-consuming and expensive process, heterogeneous mechanical tests have been proposed [1]. The heterogeneous fields that are induced can be analyzed using full-field measurement techniques. Due to the diversity of mechanical states, a large quantity of relevant information can be extracted from a single test. To the best of the authors’ knowledge, there is still a need for a systematic test design methodology. An optimization approach should be used to search for an optimal test configuration in a more efficient way than trial and error approaches. Therefore, this work aims at filling this gap by proposing a nonlinear topology-based optimization methodology for designing specimen geometries with heterogeneous displacement and strain fields.
description: This project has received funding from the Research Fund for Coal and Steel under grant agreement No 888153. The authors also acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under the project PTDC/EMEAPL/29713/2017 by UE/FEDER through the programs CENTRO 2020 and COMPETE 2020, and UID/EMS/00481/2013-FCT under CENTRO-01-0145-FEDER-022083. M. Gonçalves is grateful to the FCT for the Ph.D. grant Ref. UI/BD/151257/2021.
Artificial-Intelligence-Based Design for Circuit Parameters of Power Converters
Creators: name: Li, X.
name: Zhang, X.
name: Lin, F.
name: Blaabjerg, F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: Human-Computer Interaction (cs.HC)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Parameter design is significant in ensuring a satisfactory holistic performance of power converters. Generally, circuit parameter design for power converters consists of two processes: analysis and deduction process and optimization process. The existing approaches for parameter design consist of two types: traditional approach and computer-aided optimization (CAO) approach. In the traditional approaches, heavy human-dependence is required. Even though the emerging CAO approaches automate the optimization process, they still require manual analysis and deduction process. To mitigate human-dependence for the sake of high accuracy and easy implementation, an artificial-intelligence-based design (AI-D) approach is proposed in this article for the parameter design of power converters. In the proposed AI-D approach, to achieve automation in the analysis and deduction process, simulation tools and batch-normalization neural network (BN-NN) are adopted to build data-driven models for the optimization objectives and design constraints. Besides, to achieve automation in the optimization process, genetic algorithm is used to search for optimal design results. The proposed AI-D approach is validated in the circuit parameter design of the synchronous buck converter in the 48 to 12 V accessory-load power supply system in electric vehicle. The design case of an efficiency-optimal synchronous buck converter with constraints in volume, voltage ripple, and current ripple is provided. In the end of this article, feasibility and accuracy of the proposed AI-D approach have been validated by hardware experiments.
description: 12 pages, 20 figures
Status of a monitor design for single-shot electro-optical bunch profile measurements at FCC-ee
Creators: name: Reißig, Micha
name: Bründerrmann, Erik
name: Funkner, Stefan
name: Härer, Bastian
name: Niehues, Gudrun
name: Patil, Meghana Mahaveer
name: Widmann, Christina
name: Müller, Anke Susanne
Publisher: name: JACoW Publishing
Year: 2022

description: At the KIT electron storage ring KARA (Karlsruhe Research Accellerator) an electro-optical (EO) near-field monitor is in operation performing single-shot, turn-by-turn measurements of the longitudinal bunch profile using electro-optical spectral decoding (EOSD). In context of the Future Circular Collider Innovation Study (FCCIS), a similar setup is investigated with the aim to monitor the longitudinal bunch profile of each bunch for dedicated top-up injection at the future electron-positron collider FCC-ee. This contribution presents the status of a monitor design adapted to cope with the high-current and high-energy lepton beams foreseen at FCC-ee.
Collective dynamics of accelerated atoms
Creators: name: Richter, Benedikt
name: Terças, Hugo
name: Omar, Yasser
name: de Vega, Inés
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the collective dynamics of accelerated atoms interacting with a massless field via an Unruh-deWitt-type interaction. We first derive a general Hamiltonian describing such a system and then, employing a Markovian master equation, we study the corresponding collective dynamics. In particular, we observe that the emergence of entanglement between two-level atoms is linked to the building up of coherences between them and to superradiant emission. In addition, we show that the derived Hamiltonian can be experimentally implemented by employing impurities in Bose-Einstein condensates.
description: Published version (revised and reorganized). Keywords: collective effects, entanglement, Unruh effect, quantum simulation, open systems
Supplementary document for Asymmetric χ(2)-Translated Optical Frequency Combs Assisted by Avoided Mode Crossing in Concentric Ring Resonators - 7132783.pdf
Creators: name: Wu, Pengzhuo
name: Tang, Xingyu
name: yang, Yatao
name: wang, Yifan
name: Yongxian, Yan
name: Pan, Ziyu
name: You, Mingjian
name: Liu, Zhenyu
name: Bao, Changjing
name: ZHANG, XUCHENG
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: supplementary document
Oscillatory-like Expansion of a Fermionic Superfluid
Creators: name: Wang, Xiao-Qiong
name: Wu, Yu-Ping
name: Liu, Xiang-Pei
name: Wang, Yu-Xuan
name: Chen, Hao-Ze
name: Maraj, Mudassar
name: Deng, Youjin
name: Yao, Xing-Can
name: Chen, Yu-Ao
name: Pan, Jian-Wei
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study the expansion behaviours of a Fermionic superfluid in a cigar-shaped optical dipole trap for the whole BEC-BCS crossover and various temperatures. At low temperature ($0.06(1) T_F$), the atom cloud undergoes an anisotropic hydrodynamic expansion over 30~ms, which behaves like oscillation in the horizontal plane. By analyzing the expansion dynamics according to the superfluid hydrodynamic equation, the effective polytropic index $\barγ$ of Equation-of-State of Fermionic superfluid is extracted. The $\barγ$ values show a non-monotonic behavior over the BEC-BCS crossover, and have a good agreement with the theoretical results in the unitarity and BEC side. The normalized quasi-frequencies of the oscillatory expansion are measured, which drop significantly from the BEC side to the BCS side and reach a minimum value of 1.73 around $1/k_Fa=-0.25$. Our work improves the understanding of the dynamic properties of strongly interacting Fermi gas.
"thumb_fig1.png" of "Cross Section and Parity Violating Spin Asymmetries of $W^\pm$ Boson Production in Polarized $p+p$ Collisions at $\sqrt{s}=500$ GeV"
Creators: name: PHENIX Collaboration
Publisher: name: HEPData
Year: 2023

description: Image File
description: Large parity violating longitudinal single-spin asymmetries $A^{e^+}_L$ = $-0.86^{+0.30}_{-0.14}$ and $A^{e^-}_L$ = $0.88^{+0.12}_{-0.71}$ are observed for inclusive high transverse momentum electrons and positrons in polarized $p + p$ collisions at a center of mass energy of $\sqrt{s}$ = 500 GeV with the PHENIX detector at RHIC. These $e^{\pm}$ come mainly from the decay of $W^{\pm}$ and $Z^0$ bosons, and their asymmetries directly demonstrate parity violation in the couplings of the $W^{\pm}$ to the light quarks. The observed electron and positron yields were used to estimate $W^{\pm}$ boson production cross sections for the $e^{\pm}$ channels of $\sigma$ $(pp \rightarrow W^+ X) \times BR(W^+ \rightarrow e^+\nu_e) = 144.1 \pm 21.2$(stat)$^{+3.4}_{-10.3}$(syst)$\pm 15\%(norm)$ pb, and $\sigma (pp \rightarrow W^- X) \times BR(W^- \rightarrow e^- \bar{\nu}_e)$ = 31.7 $\pm$12.1(stat)$^{+10.1}_{-8.2}$(syst) $\pm$ 15%(norm) pb.
"thumb_fig3.png" of "Cross Section and Parity Violating Spin Asymmetries of $W^\pm$ Boson Production in Polarized $p+p$ Collisions at $\sqrt{s}=500$ GeV"
Creators: name: PHENIX Collaboration
Publisher: name: HEPData
Year: 2023

description: Image File
description: Large parity violating longitudinal single-spin asymmetries $A^{e^+}_L$ = $-0.86^{+0.30}_{-0.14}$ and $A^{e^-}_L$ = $0.88^{+0.12}_{-0.71}$ are observed for inclusive high transverse momentum electrons and positrons in polarized $p + p$ collisions at a center of mass energy of $\sqrt{s}$ = 500 GeV with the PHENIX detector at RHIC. These $e^{\pm}$ come mainly from the decay of $W^{\pm}$ and $Z^0$ bosons, and their asymmetries directly demonstrate parity violation in the couplings of the $W^{\pm}$ to the light quarks. The observed electron and positron yields were used to estimate $W^{\pm}$ boson production cross sections for the $e^{\pm}$ channels of $\sigma$ $(pp \rightarrow W^+ X) \times BR(W^+ \rightarrow e^+\nu_e) = 144.1 \pm 21.2$(stat)$^{+3.4}_{-10.3}$(syst)$\pm 15\%(norm)$ pb, and $\sigma (pp \rightarrow W^- X) \times BR(W^- \rightarrow e^- \bar{\nu}_e)$ = 31.7 $\pm$12.1(stat)$^{+10.1}_{-8.2}$(syst) $\pm$ 15%(norm) pb.
"thumb_fig4.png" of "Cross Section and Parity Violating Spin Asymmetries of $W^\pm$ Boson Production in Polarized $p+p$ Collisions at $\sqrt{s}=500$ GeV"
Creators: name: PHENIX Collaboration
Publisher: name: HEPData
Year: 2023

description: Image File
description: Large parity violating longitudinal single-spin asymmetries $A^{e^+}_L$ = $-0.86^{+0.30}_{-0.14}$ and $A^{e^-}_L$ = $0.88^{+0.12}_{-0.71}$ are observed for inclusive high transverse momentum electrons and positrons in polarized $p + p$ collisions at a center of mass energy of $\sqrt{s}$ = 500 GeV with the PHENIX detector at RHIC. These $e^{\pm}$ come mainly from the decay of $W^{\pm}$ and $Z^0$ bosons, and their asymmetries directly demonstrate parity violation in the couplings of the $W^{\pm}$ to the light quarks. The observed electron and positron yields were used to estimate $W^{\pm}$ boson production cross sections for the $e^{\pm}$ channels of $\sigma$ $(pp \rightarrow W^+ X) \times BR(W^+ \rightarrow e^+\nu_e) = 144.1 \pm 21.2$(stat)$^{+3.4}_{-10.3}$(syst)$\pm 15\%(norm)$ pb, and $\sigma (pp \rightarrow W^- X) \times BR(W^- \rightarrow e^- \bar{\nu}_e)$ = 31.7 $\pm$12.1(stat)$^{+10.1}_{-8.2}$(syst) $\pm$ 15%(norm) pb.
Structure of Stable Binary Neutron Star Merger Remnants: Role of Initial Spin
Creators: name: Kastaun, Wolfgang
name: Ciolfi, Riccardo
name: Endrizzi, Andrea
name: Giacomazzo, Bruno
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present general relativistic numerical simulations of binary neutron star (BNS) mergers with different initial spin configurations. We focus on models with stars of mass 1.4 M_sol each, which employ the equation of state (EOS) by Shen, Horowitz, and Teige, and which result in stable NSs as merger remnants. For comparison, we consider two irrotational equal mass (M=1.35 M_sol) and unequal mass (M=1.29,1.42 M_sol) BNS models using the APR4 EOS, which result in a supramassive merger remnant. We present visualizations of the fluid flow and temperature distribution and find a strong impact of the spin on vortex structure and nonaxisymmetric deformation. We compute the radial mass distribution and the rotation profile in the equatorial plane using recently developed measures independent of spatial gauge, revealing slowly rotating cores that can be well approximated by the cores of spherical stars. We also study the influence of the spin on the inspiral phase and the gravitational wave (GW) signal. Using a newly developed analysis method, we further show that gravitational waveforms from BNS mergers can exhibit one or more phase jumps after merger, which occur together with minima of the strain amplitude. We provide a natural explanation in terms of the remnant's quadrupole moment, and show that cancellation effects due to phase jumps can have a strong impact on the GW power spectrum. Finally, we discuss the impact of the spin on the amount of ejected matter.
description: 20 pages, 21 figures; updated to published version
Linear Quadratic Stochastic Optimal Control Problems with Operator Coefficients: Open-Loop Solutions
Creators: name: Wei, Qingmeng
name: Yong, Jiongmin
name: Yu, Zhiyong
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 93E20, 91A23, 49N70, 49N10

description: An optimal control problem is considered for linear stochastic differential equations with quadratic cost functional. The coefficients of the state equation and the weights in the cost functional are bounded operators on the spaces of square integrable random variables. The main motivation of our study is linear quadratic optimal control problems for mean-field stochastic differential equations. Open-loop solvability of the problem is investigated, which is characterized as the solvability of a system of linear coupled forward-backward stochastic differential equations (FBSDE, for short) with operator coefficients. Under proper conditions, the well-posedness of such an FBSDE is established, which leads to the existence of an open-loop optimal control. Finally, as an application of our main results, a general mean-field linear quadratic control problem in the open-loop case is solved.
description: to appear in ESAIM Control Optim. Calc. Var. The original publication is available at www.esaim-cocv.org (https://doi.org/10.1051/cocv/2018013)
Supplementary document for Enhanced Near-Infrared Absorption in Au-Hyperdoped Si: Interplay Between Mid-Gap States and Plasmon Resonance - 7106103.pdf
Creators: name: Peng, Songyuan
name: Wang, Tingting
name: Shaikh, Mohd Saif
name: Tian, Mingyang
name: Huang, Yijia
name: Heller, Rene
name: Zhu, Jianqi
name: Su, Yarong
name: Li, Yun
name: Xie, Zhengwei
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: Supplemental Document 1
"thumb_fig2.png" of "Cross Section and Parity Violating Spin Asymmetries of $W^\pm$ Boson Production in Polarized $p+p$ Collisions at $\sqrt{s}=500$ GeV"
Creators: name: PHENIX Collaboration
Publisher: name: HEPData
Year: 2023

description: Image File
description: Large parity violating longitudinal single-spin asymmetries $A^{e^+}_L$ = $-0.86^{+0.30}_{-0.14}$ and $A^{e^-}_L$ = $0.88^{+0.12}_{-0.71}$ are observed for inclusive high transverse momentum electrons and positrons in polarized $p + p$ collisions at a center of mass energy of $\sqrt{s}$ = 500 GeV with the PHENIX detector at RHIC. These $e^{\pm}$ come mainly from the decay of $W^{\pm}$ and $Z^0$ bosons, and their asymmetries directly demonstrate parity violation in the couplings of the $W^{\pm}$ to the light quarks. The observed electron and positron yields were used to estimate $W^{\pm}$ boson production cross sections for the $e^{\pm}$ channels of $\sigma$ $(pp \rightarrow W^+ X) \times BR(W^+ \rightarrow e^+\nu_e) = 144.1 \pm 21.2$(stat)$^{+3.4}_{-10.3}$(syst)$\pm 15\%(norm)$ pb, and $\sigma (pp \rightarrow W^- X) \times BR(W^- \rightarrow e^- \bar{\nu}_e)$ = 31.7 $\pm$12.1(stat)$^{+10.1}_{-8.2}$(syst) $\pm$ 15%(norm) pb.
Geometric criterion of topological phase transition for non-Hermitian systems
Creators: name: Fan, Annan
name: Liang, Shi-Dong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose a geometric criterion of the topological phase transition for non-Hermitian systems. We define the length of the boundary of the bulk band in the complex energy plane for non-Hermitian systems. For one-dimensional systems, we find that the topological phase transition occurs when the derivatives of the length with respect to parameters are discontinuous. For two-dimensional systems, when the length is discontinuous, the topological phase transitions between the gapped and gapless phases occurs. When the derivatives of the length with respect to parameters are discontinuous, the topological phase transition between the gapless and gapless phases occurs. These nonanalytic behaviors of the length in the complex energy plane provide a signal to detect the topological phase transitions. We demonstrate this geometric criterion by the one-dimensional non-Hermitian Su-Schieffer-Heeger model and the two-dimensional non-Hermitian Chern insulator model. This geometric criterion provides an efficient insight to the global topological invariant from a geometric local object in the complex energy plane for non-Hermitian systems
description: 24 pages, 4 figures. arXiv admin note: text overlap with arXiv:2308.05329
Supplementary document for Angular Selective Broadband Radiative Cooling Based on Berreman Mode - 7137082.pdf
Creators: name: Ryu, Dong Gyun
name: Kim, June Tae
name: Kim, Min Seong
name: Kim, Jeong Jin
name: NAM, HEEJUN
name: Jeong, Ikhoon
name: Kim, Yeong Jae
name: Lee, Gil Ju
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: Supplemental Document
Comment on "Identification of the Mott Insulating Charge Density Wave State in $1T$-TaS$_2$"
Creators: name: Pasquier, Diego
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The applicability of DFT+$U$ to the star-of-David phase of $1T$-TaS$_2$ is examined. The viability of a Mott phase as a ground state for the bulk of this material is briefly discussed in light of the available experimental evidence.
A Gaia-PS1-SDSS (GPS1) Proper Motion Catalog Covering 3/4 of the Sky
Creators: name: Tian, Hai-Jun
name: Gupta, Prashansa
name: Sesar, Branimir
name: Rix, Hans-Walter
name: Martin, Nicolas F.
name: Liu, Chao
name: Goldman, Bertrand
name: Platais, Imants
name: Kudritzki, Rolf-Peter
name: Waters, Christopher Z.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We combine Gaia DR1, PS1, SDSS and 2MASS astrometry to measure proper motions for 350 million sources across three-fourths of the sky down to a magnitude of $m_r\sim20$\,. Using positions of galaxies from PS1, we build a common reference frame for the multi-epoch PS1, single-epoch SDSS and 2MASS data, and calibrate the data in small angular patches to this frame. As the Gaia DR1 excludes resolved galaxy images, we choose a different approach to calibrate its positions to this reference frame: we exploit the fact that the proper motions of stars in these patches are {\it linear}. By simultaneously fitting the positions of stars at different epochs of -- Gaia DR1, PS1, SDSS, and 2MASS -- we construct an extensive catalog of proper motions dubbed GPS1. GPS1 has a characteristic systematic error of less than 0.3 \masyr\, and a typical precision of $ 1.5-2.0$\masyr. The proper motions have been validated using galaxies, open clusters, distant giant stars and QSOs. In comparison with other published faint proper motion catalogs, GPS1's systematic error ($<0.3$ \masyr) should be nearly an order of magnitude better than that of PPMXL and UCAC4 ($>2.0$ \masyr). Similarly, its precision ($\sim 1.5$ \masyr) is a four-fold improvement relative to PPMXL and UCAC4 ($\sim 6.0$ \masyr). For QSOs, the precision of GPS1 is found to be worse ($\sim 2.0-3.0$\masyr), possibly due to their particular differential chromatic refraction (DCR). The GPS1 catalog will be released on-line and available via the VizieR Service and VO Service. (===GPS1 is available with VO TAP Query now, see http://www2.mpia-hd.mpg.de/~tian/GPS1/ for details=== )
description: 17 pages, 19 figures, published on-line in ApJS (GPS1 is available with VO TAP Query now)
Supplementary document for Dynamic plasmonic structural color with deep sub-diffraction resolution based on borophene metasurfaces - 7140536.pdf
Creators: name: Zhang, Zhaojian
name: Du, Te
name: Jiang, Xinpeng
name: Chen, Huan
name: Zhang, Zhenfu
name: He, Xin
name: Yu, Yang
name: Yang, Junbo
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: Supplementary Document 1
Application of dense neural networks for manifold-based modeling of flame-wall interactions
Creators: name: Bissantz, Julian
name: Karpowski, Jeremy
name: Steinhausen, Matthias
name: Luo, Yujuan
name: Ferraro, Federica
name: Scholtissek, Arne
name: Hasse, Christian
name: Vervisch, Luc
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Artifical neural networks (ANNs) are universal approximators capable of learning any correlation between arbitrary input data with corresponding outputs, which can also be exploited to represent a low-dimensional chemistry manifold in the field of combustion. In this work, a procedure is developed to simulate a premixed methane-air flame undergoing side-wall quenching utilizing an ANN chemistry manifold. In the investigated case, the flame characteristics are governed by two canonical problems: the adiabatic flame propagation in the core flow and the non-adiabatic flame-wall interaction governed by enthalpy losses to the wall. Similar to the tabulation of a Quenching Flamelet-Generated Manifold (QFM), the neural network is trained on a 1D head-on quenching flame database to learn the intrinsic chemistry manifold. The control parameters (i.e. the inputs) of the ANN are identified from thermo-chemical state variables by a sparse principal component analysis (PCA) without using prior knowledge about the flame physics. These input quantities are then transported in the coupled CFD solver and used for manifold access during simulation runtime. The chemical source terms are corrected at the manifold boundaries to ensure boundedness of the thermo-chemical state at all times. Finally, the ANN model is assessed by comparison to simulation results of the 2D side-wall quenching (SWQ) configuration with detailed chemistry and with a flamelet-based manifold (QFM).
An Evolutionary Model of Subgame Perfect Equilibrium
Creators: name: Zhao, Zhongxia
Publisher: name: Carnegie Mellon University
Year: 2023
Subjects: subject: Philosophy
subject: FOS: Philosophy, ethics and religion

description: Classical game theory begins with the assumption that its agents are rational, and proceeds to find various solution concepts from these premises. These solution concepts are often interpreted as the rational way to behave in games. However, this method often faces normative (and empirical) concerns on the validity of its rationality assumptions. This is particularly the case in games with complex structures (e.g. dynamic games or games involving uncertainty), where the rationality assumptions become increasingly strong. One useful tool for evaluating these rationality assumptions is evolutionary game theory. Unlike classical game theory, evolutionary game theory makes no such assumptions of rationality, but instead begins with specifying a rule or dynamic by which the system (e.g. a population or an individual’s strategies/beliefs) evolve over time. However, most evolutionary dynamics currently treat dynamic games in their normal form - this makes them unable to properly represent the backward induction and subgame perfect equilibrium, an important solution concept specifically for dynamic games. In this thesis, I discuss some of the connections between these two theories, including examples of when they agree and disagree. I then present a modified version of a popular evolutionary dynamic (the replicator equation) that is capable of selecting for subgame perfect equilibrium. This model has two different settings that can be used to model situations of evolution (not rational) and situations of learning (rational), and is also potentially useful for modeling evolutionlearning hybrid scenarios. In addition, the new model is computationally much simpler than the original, as it breaks down the strategy space in this way.
Three-dimensional Alexandrov spaces with local isometric circle actions
Creators: name: Galaz-Garcia, Fernando
name: Núñez-Zimbrón, Jesús
Publisher: name: arXiv
Year: 2017
Subjects: subject: Differential Geometry (math.DG)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 53C23, 57S15, 57S25

description: We obtain a topological and equivariant classification of closed, connected three-dimensional Alexandrov spaces admitting a local isometric circle action. We show, in particular, that such spaces are homeomorphic to connected sums of some closed 3-manifold with a local circle action and finitely many copies of the suspension of the real projective plane.
description: 23 pages, Final version to appear at the Kyoto Journal of Mathematics
Effect of memristorś potentiation-depression curves peculiarities in the convergence of physical perceptrons
Creators: name: Quiñonez, Walter
name: Sánchez, María José
name: Rubi, Diego
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Emerging Technologies (cs.ET)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Neuromorphic computing aims to emulate the architecture and information processing mechanisms of the mammalian brain. This includes the implementation by hardware of neural networks. Oxide-based memristor arrays with cross-bar architecture appear as a possible physical implementation of neural networks.In this paper, we obtain experimental potentiation-depression (P-D) curves on different manganite-based memristive systems and simulate the learning process of perceptrons for character recognition. We analyze how the specific characteristics of the P-D curves affect the convergence time -- characterized by the EPOCHs-to-convergence (ETC) parameter -- of the network. Our work shows that ETC is reduced for systems displaying P-D curves with relatively low granularity and non-linear and asymmetric response. In addition, we also show that noise injection during the synaptic weight actualization further reduces the ETC. The results obtained here are expected to contribute to the optimization of hardware neural networks based on memristors cross-bar arrays.
description: 10 pages published version
Supplementary document for Fringe-averaged collinear Frequency-Resolved Optical Gating: in situ characterization of ultrashort pulses in nonlinear microscopy. - 7161521.pdf
Creators: name: Shivkumar, Siddarth
name: Frackleton, Leah
name: Harper, Alexander
name: Latorre, Malcolm
name: Pegoraro, Adrian
name: Stolow, Albert
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: Supplementary document
Cascades in the dynamics of affine interval exchange transformations
Creators: name: Boulanger, Adrien
name: Fougeron, Charles
name: Ghazouani, Selim
Publisher: name: arXiv
Year: 2017
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We describe in this article the dynamics of a $1$-parameter family of affine interval exchange transformations. It amounts to studying the directional foliations of a particular affine surface, the Disco surface. We show that this family displays various dynamical behaviours: it is generically dynamically trivial, but for a Cantor set of parameters the leaves of the foliations accumulate to a (transversely) Cantor set. s study is achieved through the analysis the dynamics of the Veech group of this surface combined a modified version of Rauzy induction in the context of affine interval exchange transformations.
Parseval frames of exponentially localized magnetic Wannier functions
Creators: name: Cornean, Horia D.
name: Monaco, Domenico
name: Moscolari, Massimo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences
subject: 81Q10, 81Q15, 81Q30, 81Q70

description: Motivated by the analysis of gapped periodic quantum systems in presence of a uniform magnetic field in dimension $d \le 3$, we study the possibility to construct spanning sets of exponentially localized (generalized) Wannier functions for the space of occupied states. When the magnetic flux per unit cell satisfies a certain rationality condition, by going to the momentum-space description one can model $m$ occupied energy bands by a real-analytic and $\mathbb Z^{d}$-periodic family $\{P({\bf k})\}_{{\bf k} \in \mathbb R^{d}}$ of orthogonal projections of rank $m$. A moving orthonormal basis of $\mathrm{Ran} P({\bf k})$ consisting of real-analytic and $\mathbb Z^d$-periodic Bloch vectors can be constructed if and only if the first Chern number(s) of $P$ vanish(es). Here we are mainly interested in the topologically obstructed case. First, by dropping the generating condition, we show how to algorithmically construct a collection of $m-1$ orthonormal, real-analytic, and periodic Bloch vectors. Second, by dropping the linear independence condition, we construct a Parseval frame of $m+1$ real-analytic and periodic Bloch vectors which generate $\mathrm{Ran} P({\bf k})$. Both algorithms are based on a two-step logarithm method which produces a moving orthonormal basis in the topologically trivial case. A moving Parseval frame of analytic, periodic Bloch vectors corresponds to a Parseval frame of exponentially localized composite Wannier functions. We extend this construction to the case of magnetic Hamiltonians with an irrational magnetic flux per unit cell and show how to produce Parseval frames of exponentially localized generalized Wannier functions also in this setting. Our results are illustrated in crystalline insulators modelled by $2d$ discrete Hofstadter-like Hamiltonians, but apply to certain continuous models of magnetic Schrödinger operators as well.
description: 40 pages. Improved exposition and minor corrections. Final version matches published paper on Commun. Math. Phys
Multiplicity and concentration of solutions for fractional Schrödinger systems via penalization method
Creators: name: Ambrosio, Vincenzo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: The aim of this paper is to investigate the existence, multiplicity and concentration of positive solutions for the following nonlocal system of fractional Schrödinger equations \begin{equation*} \left\{ \begin{array}{ll} \varepsilon^{2s} (-Δ)^{s}u+V(x)u=Q_{u}(u, v) &\mbox{ in } \mathbb{R}^{N}, \varepsilon^{2s} (-Δ)^{s}v+W(x)v=Q_{v}(u, v) &\mbox{ in } \mathbb{R}^{N}, u, v>0 &\mbox{ in } \mathbb{R}^{N}, \end{array} \right. \end{equation*} where $\varepsilon>0$ is a parameter, $s\in (0, 1)$, $N>2s$, $(-Δ)^{s}$ is the fractional Laplacian, $V:\mathbb{R}^{N}\rightarrow \mathbb{R}$ and $W:\mathbb{R}^{N}\rightarrow \mathbb{R}$ are positive continuous potentials, $Q$ is a homogeneous $C^{2}$-function with subcritical growth. In order to relate the number of solutions with the topology of the set where the potentials $V$ and $W$ attain their minimum values, we apply penalization techniques, Nehari manifold arguments and Ljusternik-Schnirelmann theory.
description: arXiv admin note: text overlap with arXiv:1703.04370
Supplementary document for Enhancing MINFLUX 3D imaging precision by vortex interference - 7157495.pdf
Creators: name: wang, wei
name: huang, zengxin
name: Li, hangfeng
name: Kanchanawong, Pakorn
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Classical and Physical Optics

description: supplementary document 1
Asset liquidation under drift uncertainty and regime-switching volatility
Creators: name: Vaicenavicius, Juozas
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Finance (q-fin.MF)
subject: FOS: Economics and business
subject: 60G40

description: Optimal liquidation of an asset with unknown constant drift and stochastic regime-switching volatility is studied. The uncertainty about the drift is represented by an arbitrary probability distribution; the stochastic volatility is modelled by $m$-state Markov chain. Using filtering theory, an equivalent reformulation of the original problem as a four-dimensional optimal stopping problem is found and then analysed by constructing approximating sequences of three-dimensional optimal stopping problems. An optimal liquidation strategy and various structural properties of the problem are determined. Analysis of the two-point prior case is presented in detail, building on which, an outline of the extension to the general prior case is given.
description: 30 pages, some minor improvements
Autocorrelation and Lower Bound on the 2-Adic Complexity of LSB Sequence of $p$-ary $m$-Sequence
Creators: name: Sun, Yuhua
name: Wang, Qiuyan
name: Yan, Tongjiang
name: Zhao, Chun'e
Publisher: name: arXiv
Year: 2017
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: LSB (Least Significant Bit) sequences are widely used as the initial inputs in some modern stream ciphers, such as the ZUC algorithm-the core of the 3GPP LTE International Encryption Standard. Therefore, analyzing the statistical properties (for example, autocorrelation, linear complexity and 2-adic complexity) of these sequences becomes an important research topic. In this paper, we first reduce the autocorrelation distribution of the LSB sequence of a $p$-ary $m$-sequence with period $p^n-1$ for any order $n\geq2$ to the autocorrelation distribution of a corresponding Costas sequence with period $p-1$, and from the computing of which by computer, we obtain the explicit autocorrelation distribution of the LSB sequence for each prime $p<100$. In addition, we give a lower bound on the 2-adic complexity of each of these LSB sequences for all primes $p < 20$, which proves to be large enough to resist the analysis of RAA (Rational Approximation Algorithm) for FCSRs (Feedback with Carry Shift Registers). In particular, for a Mersenne prime $p=2^k-1$ (i.e., $k$ is a prime such that $p$ is also a prime), our results hold for all its bit-component sequences since they are shift equivalent to the LSB sequence.
description: 16 pages. arXiv admin note: text overlap with arXiv:1701.03766
Flare forecasting at the Met Office Space Weather Operations Centre
Creators: name: Murray, Sophie A.
name: Bingham, Suzy
name: Sharpe, Michael
name: Jackson, David R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: The Met Office Space Weather Operations Centre produces 24/7/365 space weather guidance, alerts, and forecasts to a wide range of government and commercial end users across the United Kingdom. Solar flare forecasts are one of its products, which are issued multiple times a day in two forms; forecasts for each active region on the solar disk over the next 24 hours, and full-disk forecasts for the next four days. Here the forecasting process is described in detail, as well as first verification of archived forecasts using methods commonly used in operational weather prediction. Real-time verification available for operational flare forecasting use is also described. The influence of human forecasters is highlighted, with human-edited forecasts outperforming original model results, and forecasting skill decreasing over longer forecast lead times.
description: Accepted for publication in Space Weather. 18 pages, 8 figures, 3 tables
Criteria for generalized translation-invariant frames
Creators: name: Lemvig, Jakob
name: van Velthoven, Jordy Timo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42C15, 42C40 (Primary), 43A32, 43A60, 43A70 (Secondary)

description: This paper provides new sufficient and necessary conditions for the frame property of generalized translation-invariant systems. The conditions are formulated in the Fourier domain and consists of estimates involving the upper and lower frame bound. Contrary to known conditions of a similar nature, the estimates take the phase of the generating functions in consideration and not only their modulus. The possibility of phase cancellations makes these estimates optimal for tight frames. The results on generalized translation-invariant systems will be proved in the setting of locally compact abelian groups, but even for euclidean space and the special case of (composite) wavelet systems the results are new.
description: To appear in Studia Mathematica
Physical Layer Security for NOMA Systems: Requirements, Issues, and Recommendations
Creators: name: Pakravan, Saeid
name: Chouinard, Jean-Yves
name: Li, Xingwang
name: Zeng, Ming
name: Hao, Wanming
name: Pham, Quoc-Viet
name: Dobre, Octavia A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Non-orthogonal multiple access (NOMA) has been viewed as a potential candidate for the upcoming generation of wireless communication systems. Comparing to traditional orthogonal multiple access (OMA), multiplexing users in the same time-frequency resource block can increase the number of served users and improve the efficiency of the systems in terms of spectral efficiency. Nevertheless, from a security view-point, when multiple users are utilizing the same time-frequency resource, there may be concerns regarding keeping information confidential. In this context, physical layer security (PLS) has been introduced as a supplement of protection to conventional encryption techniques by making use of the random nature of wireless transmission media for ensuring communication secrecy. The recent years have seen significant interests in PLS being applied to NOMA networks. Numerous scenarios have been investigated to assess the security of NOMA systems, including when active and passive eavesdroppers are present, as well as when these systems are combined with relay and reconfigurable intelligent surfaces (RIS). Additionally, the security of the ambient backscatter (AmB)-NOMA systems are other issues that have lately drawn a lot of attention. In this paper, a thorough analysis of the PLS-assisted NOMA systems research state-of-the-art is presented. In this regard, we begin by outlining the foundations of NOMA and PLS, respectively. Following that, we discuss the PLS performances for NOMA systems in four categories depending on the type of the eavesdropper, the existence of relay, RIS, and AmB systems in different conditions. Finally, a thorough explanation of the most recent PLS-assisted NOMA systems is given.
description: 17 pages, 4 figures
Supplementary document for Design, simulation and experimental realization of a novel high-sensitivity polarization-independent electromagnetically induced transparent terahertz metamaterials. - 7153344.pdf
Creators: name: Lei, Jiangtao
name: Zhou, Xinwei
name: Li, Le
name: Shen, Yun
name: Hong, Lujun
name: Guo, Tianjing
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: supplementary document
Supplementary document for Design, simulation and experimental realization of a novel high-sensitivity polarization-independent electromagnetically induced transparent terahertz metamaterials. - 7166855.pdf
Creators: name: Zhou, Xinwei
name: Li, Le
name: Shen, Yun
name: Hong, Lujun
name: Guo, Tianjing
name: Lei, Jiangtao
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: supplementary document
Supplementary document for Design, simulation and experimental realization of a novel high-sensitivity polarization-independent electromagnetically induced transparent terahertz metamaterials. - 7087414.pdf
Creators: name: Zhou, Xinwei
name: Li, Le
name: Shen, Yun
name: Hong, Lujun
name: Lin, Dongdong
name: Guo, Tianjing
name: Lei, Jiangtao
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: This material contains three supplemental figures.
Flat bands and compactons in mechanical lattices
Creators: name: Perchikov, Nathan
name: Gendelman, O. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Local configurational symmetry in lattice structures may give rise to stationary, compact solutions, even in the absence of disorder and nonlinearity. These compact solutions are related to the existence of flat dispersion curves (bands). Nonlinearity can destabilize such compactons. One common flat-band-generating system is the 1D cross-stitch model, in which compactons were shown to exist for the photonic lattice with Kerr nonlinearity. The compactons exist there already in the linear regime and are not generally destructed by that nonlinearity. Smooth nonlinearity of this kind does not allow doing a complete stability analysis for this chain. We consider a discrete mechanical system with flat dispersion bands, in which the nonlinearity exists due to impact constraints. There, one can use the concept of the saltation matrix for the analytic construction of the monodromy matrix. Besides, we consider a smooth nonlinear lattice with linearly connected massless boxes, each containing two symmetric anharmonic oscillators. In this model, the flat bands and discrete compactons also readily emerge. This system also permits performing comprehensive stability analysis, at least in the anti-continuum limit, due to the reduced number of degrees-of-freedom. In both systems, there exist two types of localization. The first one is the complete localization, and the second one is the more common exponential localization. The latter type is associated with discrete breathers (DBs). Two principal mechanisms for the loss of stability are revealed. The first one is the possible internal instability of the symmetric and/or antisymmetric solution in the individual unit cell of the chain. One can interpret this instability pattern as internal resonance between the compacton and the DB. The other mechanism is global instability related to resonance of the stationary solution with the propagation frequencies.
description: 26 pages, 27 figures
Rational growth and degree of commutativity of graph products
Creators: name: Valiunas, Motiejus
Publisher: name: arXiv
Year: 2017
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 20F36, 20P05

description: Let $G$ be an infinite group and let $X$ be a finite generating set for $G$ such that the growth series of $G$ with respect to $X$ is a rational function; in this case $G$ is said to have rational growth with respect to $X$. In this paper a result on sizes of spheres (or balls) in the Cayley graph $Γ(G,X)$ is obtained: namely, the size of the sphere of radius $n$ is bounded above and below by positive constant multiples of $n^αλ^n$ for some integer $α\geq 0$ and some $λ\geq 1$. As an application of this result, a calculation of degree of commutativity (d. c.) is provided: for a finite group $F$, its d. c. is defined as the probability that two randomly chosen elements in $F$ commute, and Antolín, Martino and Ventura have recently generalised this concept to all finitely generated groups. It has been conjectured that the d. c. of a group $G$ of exponential growth is zero. This paper verifies the conjecture (for certain generating sets) when $G$ is a right-angled Artin group or, more generally, a graph product of groups of rational growth in which centralisers of non-trivial elements are "uniformly small".
description: 16 pages; final version