cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Effects of transcranial direct current stimulation over the Broca’s area on tongue twister production
Creators: name: Wong, Min Ney
name: Yanky Chan
name: Manwa L. Ng
name: Zhu, Frank F.
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Physiology
subject: Biotechnology
subject: Ecology
subject: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy

description: Purpose: The present study aimed to explore the short-term effect of anodal transcranial direct current stimulation (tDCS) on tongue twister production. Method: Thirty healthy native Cantonese adult speakers were randomly assigned to the anodal tDCS group or the sham tDCS group. Anodal tDCS of 2 mA was applied over the Broca’s area of the brain. The stimulation lasted for 20 min for the anodal tDCS group and 30 s for the sham tDCS group. The participants were instructed to produce a list of tongue twisters before, immediately after and 4 h after tDCS. Result: Speech rate and response accuracy measured immediately after stimulation were significantly faster and higher, respectively, than before stimulation. Although there was no change in speech rate measured at 4 h after stimulation, response accuracy at that time point was significantly lower than that measured immediately after stimulation. However, there were no significant differences between the anodal tDCS and sham tDCS groups in either speech rate or response accuracy. Conclusion: The findings revealed that a single session of anodal tDCS over the Broca’s area did not significantly improve speech production during tongue twister production.
Spin-spin correlation functions of spin systems coupled to 2-d quantum gravity for $0 < c < 1$
Creators: name: Ambjorn, J.
name: Anagnostopoulos, K. N.
name: Magnea, U.
name: Thorleifsson, G.
Publisher: name: arXiv
Year: 1996
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We perform Monte Carlo simulations of 2-d dynamically triangulated surfaces coupled to Ising and three--states Potts model matter. By measuring spin-spin correlation functions as a function of the geodesic distance we provide substantial evidence for a diverging correlation length at $β_c$. The corresponding scaling exponents are directly related to the KPZ exponents of the matter fields as conjectured in [4] (NPB454(1995)313).
description: Talk presented at LATTICE96(gravity)
Validation of the in-flight calibration procedures for the MICROSCOPE space mission
Creators: name: Hardy, Emilie
name: Levy, Agnès
name: Rodrigues, Manuel
name: Touboul, Pierre
name: Métris, Gilles
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The MICROSCOPE space mission aims to test the Equivalence Principle with an accuracy of $10^{-15}$. The drag-free micro-satellite will orbit around the Earth and embark a differential electrostatic accelerometer including two cylindrical test masses submitted to the same gravitational field and made of different materials. The experience consists in testing the equality of the electrostatic acceleration applied to the masses to maintain them relatively motionless. The accuracy of the measurements exploited for the test of the Equivalence Principle is limited by our a priori knowledge of several physical parameters of the instrument. These parameters are partially estimated on-ground, but with an insufficient accuracy, and an in-orbit calibration is therefore required to correct the measurements. The calibration procedures have been defined and their analytical performances have been evaluated. In addition, a simulator software including the dynamics model of the instrument, the satellite drag-free system and the perturbing environment has been developed to numerically validate the analytical results. After an overall presentation of the MICROSCOPE mission, this paper will describe the calibration procedures and focus on the simulator. Such an in-flight calibration is mandatory for similar space missions taking advantage of a drag-free system.
description: 29 pages, 7 figures, 3 tables, publication in Advances in Space Research
Multifrequency and multimode topological waveguides in a Stampfli-triangle photonic crystal with large valley Chern numbers
Creators: name: Yan, Bei
name: Peng, Yiwei
name: Xie, Jianlan
name: Peng, Yuchen
name: Shi, Aoqian
name: Li, Hang
name: Gao, Feng
name: Peng, Peng
name: Jiang, Jiapei
name: Gao, Fei
name: Liu, Jianjun
name: Wen, Shuangchun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The multifrequency quantum valley Hall effect (QVHE) with a large valley Chern number has been realized to significantly improve the transmission capacity of topological waveguides and increase the mode density of topological waveguides. However, multifrequency and multimode QVHEs have not been realized simultaneously. In this work, using tight-binding model calculations and numerical simulations, a valley photonic crystal (VPC) consisting of a Stampfli-triangle photonic crystal is constructed, and its multiple degeneracies in the low-frequency and high-frequency bands split simultaneously to realize the QVHE with multiple topological edge states (TESs). The multifrequency and multimode topological transmission with two low-frequency modes and four high-frequency modes is realized by means of simulations and experiments through a Z-shaped waveguide constructed using two VPCs with opposite valley Chern numbers to prove the realization of a large valley Chern number in the two frequency bands. The two low-frequency modes are successfully distinguished with position-dependent selective excitations, which experimentally demonstrates the occurrence of a large valley Chern number. A frequency-dependent multimode beam splitter is theoretically proposed for high-performance integrated photonic device applications. These results provide new ideas for high-efficiency and high-capacity optical transmission and communication devices and their integration; furthermore, they broaden the application range of TESs.
Multi-Player Bandits Revisited
Creators: name: Besson, Lilian
name: Kaufmann, Emilie
Publisher: name: arXiv
Year: 2017
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Multi-player Multi-Armed Bandits (MAB) have been extensively studied in the literature, motivated by applications to Cognitive Radio systems. Driven by such applications as well, we motivate the introduction of several levels of feedback for multi-player MAB algorithms. Most existing work assume that sensing information is available to the algorithm. Under this assumption, we improve the state-of-the-art lower bound for the regret of any decentralized algorithms and introduce two algorithms, RandTopM and MCTopM, that are shown to empirically outperform existing algorithms. Moreover, we provide strong theoretical guarantees for these algorithms, including a notion of asymptotic optimality in terms of the number of selections of bad arms. We then introduce a promising heuristic, called Selfish, that can operate without sensing information, which is crucial for emerging applications to Internet of Things networks. We investigate the empirical performance of this algorithm and provide some first theoretical elements for the understanding of its behavior.
Automorphism and outer automorphism groups of Right-angled Artin groups are not relatively hyperbolic
Creators: name: Kim, Junseok
name: Oh, Sangrok
name: Tranchida, Philippe
Publisher: name: arXiv
Year: 2021
Subjects: subject: Group Theory (math.GR)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We show that the automorphism groups of right-angled Artin groups whose defining graphs have at least 3 vertices are not relatively hyperbolic. We then show that the outer automorphism groups are not relatively hyperbolic, if they are not virtually isomorphic to a right-angled Artin group whose defining graph is either a single vertex or disconnected.
description: We correct the theorem of relative hyperbolicity of outer automorphism groups of right-angled Artin groups. The corrigendum will appear in Bulletin of the Australian Mathematical Society
Intermediate dimensions of infinitely generated attractors
Creators: name: Banaji, Amlan
name: Fraser, Jonathan M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: Classical Analysis and ODEs (math.CA)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 28A80 (Primary), 37B10, 11K50 (Secondary)

description: We study the dimension theory of limit sets of iterated function systems consisting of a countably infinite number of contractions. Our primary focus is on the intermediate dimensions: a family of dimensions depending on a parameter $θ\in [0,1]$ which interpolate between the Hausdorff and box dimensions. Our main results are in the case when all the contractions are conformal. Under a natural separation condition we prove that the intermediate dimensions of the limit set are the maximum of the Hausdorff dimension of the limit set and the intermediate dimensions of the set of fixed points of the contractions. This builds on work of Mauldin and Urbański concerning the Hausdorff and upper box dimension. We give several (often counter-intuitive) applications of our work to dimensions of projections, fractional Brownian images, and general Hölder images. These applications apply to well-studied examples such as sets of numbers which have real or complex continued fraction expansions with restricted entries.
 We also obtain several results without assuming conformality or any separation conditions. We prove general upper bounds for the Hausdorff, box and intermediate dimensions of infinitely generated attractors in terms of a topological pressure function. We also show that the limit set of a 'generic' infinite iterated function system has box and intermediate dimensions equal to the ambient spatial dimension, where 'generic' can mean either 'full measure' or 'comeagre.'
description: 31 pages, 1 figure. Versions 3 and 4 include minor post-publication corrections, in particular a slight change to property (4) in Definition 2.3, and to the conditions on the set P
Quelques classes caracteristiques en theorie des nombres
Creators: name: Karoubi, Max
name: Lambre, Thierry
Publisher: name: arXiv
Year: 2000
Subjects: subject: Number Theory (math.NT)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics

description: Let A be an arbitrary ring. We introduce a Dennis trace map mod n, from K_1(A;Z/n) to the Hochschild homology group with coefficients HH_1(A;Z/n). If A is the ring of integers in a number field, explicit elements of K_1(A,Z/n) are constructed and the values of their Dennis trace mod n are computed. If F is a quadratic field, we obtain this way non trivial elements of the ideal class group of A. If F is a cyclotomic field, this trace is closely related to Kummer logarithmic derivatives; this trace leads to an unexpected relationship between the first case of Fermat last theorem, K-theory and the number of roots of Mirimanoff polynomials.
Diophantine approximation in metric space
Creators: name: Fraser, Jonathan M.
name: Koivusalo, Henna
name: Ramirez, Felipe A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: Diophantine approximation is traditionally the study of how well real numbers are approximated by rationals. We propose a model for studying Diophantine approximation in an arbitrary totally bounded metric space where the rationals are replaced with a countable hierarchy of `well-spread' points, which we refer to as abstract rationals. We prove various Jarnik-Besicovitch type dimension bounds and investigate their sharpness.
description: 17 pages
Asymptotic Expansion of Warlimont Functions on Wright Semigroups
Creators: name: Aldi, Marco
name: Tan, Hanqiu
Publisher: name: arXiv
Year: 2017
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: We calculate full asymptotic expansions of prime-independent multiplicative functions on additive arithmetic semigroups that satisfy a strong form of Knopfmacher's axioms. When applied to the semigroup of unlabeled graphs, our method yields detailed asymptotic information on how graphs decompose into connected components. As a second class of examples, we discuss polynomials in several variables over a finite field.
The infrared counterpart to the magnetar 1RXS J170849.0-400910
Creators: name: Durant, Martin
name: van Kerkwijk, Marten H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have analyzed both archival and new infrared imaging observations of the field of the Anomalous X-ray Pulsar 1RXS J170849.0-400910, in search of the infrared counterpart. This field has been previously investigated, and one of the sources consistent with the position of the AXP suggested as the counterpart. We, however, find that this object is more likely a background star, while another object within the positional error circle has non-stellar colors and shows evidence for variability. These two pieces of evidence, along with a consistency argument for the X-ray-to-infrared flux ratio, point to the second source being the more likely infrared counterpart to the AXP.
description: 19 pages AASTEX, 4 figure. Accepted for publication in ApJ. Full resolution figures at: http://www.astro.utoronto.ca/~durant/1708.ps.gz
Fractal uncertainty for transfer operators
Creators: name: Dyatlov, Semyon
name: Zworski, Maciej
Publisher: name: arXiv
Year: 2017
Subjects: subject: Dynamical Systems (math.DS)
subject: Analysis of PDEs (math.AP)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics

description: We show directly that the fractal uncertainty principle of Bourgain-Dyatlov [arXiv:1612.09040] implies that there exists $ σ> 0 $ for which the Selberg zeta function for a convex co-compact hyperbolic surface has only finitely many zeros with $ \Re s \geq \frac12 - σ$. That eliminates advanced microlocal techniques of Dyatlov-Zahl [arXiv:1504.06589] though we stress that these techniques are still needed for resolvent bounds and for possible generalizations to the case of non-constant curvature.
description: 25 pages, 5 figures; minor revisions. To appear in IMRN
Obstructions to nonnegative curvature and rational homotopy theory
Creators: name: Belegradek, Igor
name: Kapovitch, Vitali
Publisher: name: arXiv
Year: 2000
Subjects: subject: Differential Geometry (math.DG)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 53C20, 55P62

description: We establish a link between rational homotopy theory and the problem which vector bundles admit complete Riemannian metric of nonnegative sectional curvature. As an application, we show for a large class of simply-connected nonnegatively curved manifolds that, if C lies in the class and T is a torus of positive dimension, then "most" vector bundles over the product of C and T admit no complete nonnegatively curved metric.
description: Fixed an error is the proof of lemma B.1
Dimensions of Kleinian orbital sets
Creators: name: Bartlett, Thomas
name: Fraser, Jonathan M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: Classical Analysis and ODEs (math.CA)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: primary: 37F32, 28A80, secondary: 30F40, 28A78, 11J72

description: Given a non-empty bounded subset of hyperbolic space and a Kleinian group acting on that space, the orbital set is the orbit of the given set under the action of the group. We may view orbital sets as bounded (often fractal) subsets of Euclidean space. We prove that the upper box dimension of an orbital set is given by the maximum of three quantities: the upper box dimension of the given set; the Poincaré exponent of the Kleinian group; and the upper box dimension of the limit set of the Kleinian group. Since we do not make any assumptions about the Kleinian group, none of the terms in the maximum can be removed in general. We show by constructing an explicit example that the (hyperbolic) boundedness assumption on $C$ cannot be removed in general.
description: 11 pages
Social-IWSTCNN: A Social Interaction-Weighted Spatio-Temporal Convolutional Neural Network for Pedestrian Trajectory Prediction in Urban Traffic Scenarios
Creators: name: Zhang, Chi
name: Berger, Christian
name: Dozza, Marco
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Pedestrian trajectory prediction in urban scenarios is essential for automated driving. This task is challenging because the behavior of pedestrians is influenced by both their own history paths and the interactions with others. Previous research modeled these interactions with pooling mechanisms or aggregating with hand-crafted attention weights. In this paper, we present the Social Interaction-Weighted Spatio-Temporal Convolutional Neural Network (Social-IWSTCNN), which includes both the spatial and the temporal features. We propose a novel design, namely the Social Interaction Extractor, to learn the spatial and social interaction features of pedestrians. Most previous works used ETH and UCY datasets which include five scenes but do not cover urban traffic scenarios extensively for training and evaluation. In this paper, we use the recently released large-scale Waymo Open Dataset in urban traffic scenarios, which includes 374 urban training scenes and 76 urban testing scenes to analyze the performance of our proposed algorithm in comparison to the state-of-the-art (SOTA) models. The results show that our algorithm outperforms SOTA algorithms such as Social-LSTM, Social-GAN, and Social-STGCNN on both Average Displacement Error (ADE) and Final Displacement Error (FDE). Furthermore, our Social-IWSTCNN is 54.8 times faster in data pre-processing speed, and 4.7 times faster in total test speed than the current best SOTA algorithm Social-STGCNN.
description: 8 pages, 4 figures. Accepted in IEEE Intelligent Vehicles Symposium (IV), 2021
Regularity properties of $k$-Brjuno and Wilton functions
Creators: name: Lee, Seul Bee
name: Marmi, Stefano
name: Petrykiewicz, Izabela
name: Schindler, Tanja I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 30B70, 37F50, 32A50, 46F15, 32A37, 11F03

description: We study functions related to the classical Brjuno function, namely $k$-Brjuno functions and the Wilton function. Both appear in the study of boundary regularity properties of (quasi) modular forms and their integrals. We consider various possible versions of them, based on the $α$-continued fraction developments. We study their BMO regularity properties and their behaviour near rational numbers of their finite truncations.
description: 64 pages, comments welcome
Quantum Measurement Classification with Qudits
Creators: name: Useche, Diego H.
name: Giraldo-Carvajal, Andres
name: Zuluaga-Bucheli, Hernan M.
name: Jaramillo-Villegas, Jose A.
name: González, Fabio A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: This paper presents a hybrid classical-quantum program for density estimation and supervised classification. The program is implemented as a quantum circuit in a high-dimensional quantum computer simulator. We show that the proposed quantum protocols allow to estimate probability density functions and to make predictions in a supervised learning manner. This model can be generalized to find expected values of density matrices in high-dimensional quantum computers. Experiments on various data sets are presented. Results show that the proposed method is a viable strategy to implement supervised classification and density estimation in a high-dimensional quantum computer.
description: 15 pages, 10 figures
Convergence of a Jacobi-type method for the approximate orthogonal tensor diagonalization
Creators: name: Begovic, Erna
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 15A69, 65F25, 65F99

description: For a general third-order tensor $\mathcal{A}\in\mathbb{R}^{n\times n\times n}$ the paper studies two closely related problems, an SVD-like tensor decomposition and an (approximate) tensor diagonalization. We develop a Jacobi-type algorithm that works on $2\times2\times2$ subtensors and, in each iteration, maximizes the sum of squares of its diagonal entries. We show how the rotation angles are calculated and prove convergence of the algorithm. Different initializations of the algorithm are discussed, as well as the special cases of symmetric and antisymmetric tensors. The algorithm can be generalized to work on higher-order tensors.
description: 16 pages, 4 figures
Additional file 14 of CTCF is selectively required for maintaining chromatin accessibility and gene expression in human erythropoiesis
Creators: name: Yang, Xue
name: Cheng, Li
name: Xin, Ye
name: Zhang, Jianxiang
name: Chen, Xinfeng
name: Xu, Jinchao
name: Zhang, Mengli
name: Feng, Ruopeng
name: Hyle, Judith
name: Qi, Wenjie
name: Rosikiewicz, Wojciech
name: Xu, Beisi
name: Li, Chunliang
name: Xu, Peng
Publisher: name: figshare
Year: 2025
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 14. Uncropped images for the blots in figure 1b, figure 5h and supplementary figure S1a.
Multi-Particle Tunneling Transport at Strongly-Correlated Interfaces
Creators: name: Tajima, Hiroyuki
name: Oue, Daigo
name: Matsuo, Mamoru
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We elucidate the multi-particle transport of pair- and spin-tunnelings in strongly correlated interfaces. Not only usual single-particle tunneling but also interaction-induced multi-particle tunneling processes naturally arise from a conventional microscopic model without any empirical parameters, through the overlap of the many-body wave functions around the interface. We demonstrate how anomalous tunneling currents occur in a strongly interacting system due to the pair-tunneling process which we derived microscopically. Our formulation is useful for junction systems in various disciplines, including atomtronics, spintronics, and nuclear reactions.
description: 9 pages, 2 figures
Evolution of magnetized, differentially rotating neutron stars: Simulations in full general relativity
Creators: name: Duez, Matthew D.
name: Liu, Yuk Tung
name: Shapiro, Stuart L.
name: Shibata, Masaru
name: Stephens, Branson C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the effects of magnetic fields on the evolution of differentially rotating neutron stars, which can form in stellar core collapse or binary neutron star coalescence. Magnetic braking and the magnetorotational instability (MRI) both redistribute angular momentum; the outcome of the evolution depends on the star's mass and spin. Simulations are carried out in axisymmetry using our recently developed codes which integrate the coupled Einstein-Maxwell-MHD equations. For initial data, we consider three categories of differentially rotating, equilibrium configurations, which we label normal, hypermassive and ultraspinning. Hypermassive stars have rest masses exceeding the mass limit for uniform rotation. Ultraspinning stars are not hypermassive, but have angular momentum exceeding the maximum for uniform rotation at the same rest mass. We show that a normal star will evolve to a uniformly rotating equilibrium configuration. An ultraspinning star evolves to an equilibrium state consisting of a nearly uniformly rotating central core, surrounded by a differentially rotating torus with constant angular velocity along magnetic field lines, so that differential rotation ceases to wind the magnetic field. In addition, the final state is stable against the MRI, although it has differential rotation. For a hypermassive neutron star, the MHD-driven angular momentum transport leads to catastrophic collapse of the core. The resulting rotating black hole is surrounded by a hot, massive, magnetized torus undergoing quasistationary accretion, and a magnetic field collimated along the spin axis--a promising candidate for the central engine of a short gamma-ray burst. (Abridged)
description: 27 pages, 30 figures
Thermodynamics for two flavor QCD
Creators: name: Bernard, C.
name: Blum, T.
name: DeTar, C. E.
name: Gottlieb, Steven
name: Heller, U. M.
name: Hetrick, J. E.
name: Karkkainen, L.
name: McNeile, C.
name: Rummukainen, K.
name: Sugar, R. L.
name: Toussaint, D.
name: Wingate, M.
Publisher: name: arXiv
Year: 1996
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We conclude our analysis of the N_t=6 equation of state for two flavor QCD, first described at last year's conference. We have obtained new runs at am_q=0.025 and improved runs at am_q=0.0125. The results are extrapolated to m_q=0, and we extract the speed of sound as well. We also present evidence for a restoration of the SU(2) X SU(2) chiral symmetry just above the crossover, but not of the axial U(1) chiral symmetry.
description: Poster presented at LATTICE96(finite temperature). 4 pages, LaTeX plus 5 encapsulated Postscript figures
Hot Carrier Dynamics in Photoexcited Gold Nanostructures: Role of Interband Excitations and Evidence for Ballistic Transport
Creators: name: Tagliabue, Giulia
name: Jermyn, Adam S
name: Sundararaman, Ravishankar
name: Welch, Alex J
name: DuChene, Joseph S
name: Davoyan, Artur R
name: Narang, Prineha
name: Atwater, Harry A
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Harnessing short-lived photoexcited electron-hole pairs in metal nanostructures has the potential to define a new phase of optoelectronics, enabling control of athermal mechanisms for light harvesting, photodetection and photocatalysis. To date, however, the spatiotemporal dynamics and transport of these photoexcited carriers have been only qualitatively characterized. Plasmon excitation has been widely viewed as an efficient mechanism for generating non-thermal hot carriers. Despite numerous experiments, conclusive evidence elucidating and quantifying the full dynamics of hot carrier generation, transport, and injection has not been reported. Here, we combine experimental measurements with coupled first-principles electronic structure theory and Boltzmann transport calculations to provide unprecedented insight into the internal quantum efficiency, and hence internal physics, of hot carriers in photoexcited gold (Au)-gallium nitride (GaN) nanostructures. Our results indicate that photoexcited electrons generated in 20 nm-thick Au nanostructures impinge ballistically on the Au-GaN interface. This discovery suggests that the energy of hot carriers could be harnessed from metal nanostructures without substantial losses via thermalization. Measurements and calculations also reveal the important role of metal band structure in hot carrier generation at energies above the interband threshold of the plasmonic nanoantenna. Taken together, our results advance the understanding of excited carrier dynamics in realistically-scaled metallic nanostructures and lay the foundations for the design of new optoelectronic devices that operate in the ballistic regime.
description: 9 pages, 4 figures
Space-squeezing optics in the microwave spectral region
Creators: name: Mrnka, Michal
name: Hendry, Euan
name: Láčík, Jaroslav
name: Lennon, Rachel A.
name: Barr, Lauren E.
name: Hooper, Ian R.
name: Phillips, David B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Optical systems often consist largely of empty space, as diffraction effects that occur through free-space propagation can be crucial to their function. Contracting these voids offers a path to the miniaturisation of a wide range of optical devices. Recently, a new optical element - coined a 'spaceplate' - has been proposed, that is capable of emulating the effects of diffraction over a specified propagation distance using a thinner non-local metamaterial [Nat. Commun. 12, 3512 (2021)]. The compression factor of such an element is given by the ratio of the length of free-space that is replaced to the thickness of the spaceplate itself. In this work we test a prototype spaceplate in the microwave spectral region (20-23\,GHz) - the first such demonstration designed to operate in ambient air. Our device consists of a Fabry-Pérot cavity formed from two reflective metasurfaces, with a compression factor that can be tuned by varying the size of perforations within each layer. Using a pair of directive horn antennas, we measure a space compression factor of up to approx. 6 over an NA of 0.34 and fractional bandwidth of 6%. We also investigate the fundamental trade-offs that exist between the compression factor, transmission efficiency, numerical aperture (NA) and bandwidth of this single resonator spaceplate design, and highlight that it can reach arbitrarily high compression factors by restricting its NA and bandwidth.
description: 23 pages
Purchasing, inventory control, pricing, and contract design under purchasing price uncertainties
Creators: name: Hu, Xiangling
Publisher: name: Washington State University
Year: 2008
Subjects: Purchasing -- Mathematical models

description: This dissertation focuses on exploring how companies design and adjust purchasing, inventory, and selling strategies when facing stochastic purchasing prices. First we develops a supply contract that considers environments with changing prices, we then investigate characterization properties of the price processes, and determine expressions of the contract's expected low price and its second moment for a given horizon, then we identify an expected optimum time before the contract expires at which the lowest price occurs. Simulation experiments verify our analysis, and they illustrate how the optimum purchase time decreases as the change rate of the cost increases. Next, we analyze purchasing strategies for retailers regarding the best timing and amount of purchases when operating under combined timing and quantity flexibility contracts in an environment of uncertain prices. To decrease the computational complexity and make the procedure adaptable to the case of multiple suppliers, we develop, analyze, and compare a Time Strategy and a Target Strategy and then combine these methods into an approximate algorithm to facilitate the purchasing decision in a more efficient way. We then extend the solution procedure to the multiple suppliers case. Last we study the problem of planning the procurement and sales for a newsvendor for whom the price of the raw material fluctuates along time and the demand of the output product is random and price-sensitive. After we provide a backward deduction method to solve this problem, we provide an efficient solution algorithm adapted for multiple-supplier cases and long-term-length scenarios, and a corresponding lower bound for the expected profit. We further analyze how to choose between a forward contract and spot market purchasing. Then we extend the above analysis to the profit and risk analysis in multiple-supplier cases and multiple-period newsvendor cases. Through numerical analysis we demonstrate how the potential supplier base and the parameters influence profit and risk, and the purchasing decisions.
Microscopic theory of cavity-enhanced single-photon emission from optical two-photon Raman processes
Creators: name: Breddermann, Dominik
name: Praschan, Tom
name: Heinze, Dirk
name: Binder, Rolf
name: Schumacher, Stefan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We consider cavity-enhanced single-photon generation from stimulated two-photon Raman processes in three-level systems. We compare four fundamental system configurations, one $Λ$-, one V- and two ladder ($Ξ$-) configurations. These can be realized as subsystems of a single quantum dot or of quantum-dot molecules. For a new microscopic understanding of the Raman process, we analyze the Heisenberg equation of motion applying the cluster-expansion scheme. Within this formalism an exact and rigorous definition of a cavity-enhanced Raman photon via its corresponding Raman correlation is possible. This definition for example enables us to systematically investigate the on-demand potential of Raman-transition-based single-photon sources. The four system arrangements can be divided into two subclasses, $Λ$-type and V-type, which exhibit strongly different Raman-emission characteristics and Raman-emission probabilities. Moreover, our approach reveals whether the Raman path generates a single photon or just induces destructive quantum interference with other excitation paths. Based on our findings and as a first application, we gain a more detailed understanding of experimental data from the literature. Our analysis and results are also transferable to the case of atomic three-level-resonator systems, and can be extended to more complicated multi-level schemes.
Exact versus approximate beaming formulas in Gamma-Ray Burst afterglows
Creators: name: Bianco, Carlo Luciano
name: Ruffini, Remo
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the exact analytic expressions to compute, assuming the emitted Gamma-Ray Burst (GRB) radiation is not spherically symmetric but is confined into a narrow jet, the value of the detector arrival time at which we start to "see" the sides of the jet, both in the fully radiative and adiabatic regimes. We obtain this result using our exact analytic expressions for the EQuiTemporal Surfaces (EQTSs) in GRB afterglows. We re-examine the validity of three different approximate formulas currently adopted for the adiabatic regime in the GRB literature. We also present an empirical fit of the numerical solutions of the exact equations, compared and contrasted with the three above approximate formulas. The extent of the differences is such as to require a reassessment on the existence and entity of beaming in the cases considered in the current literature, as well as on its consequences on the GRB energetics.
description: 4 pages, 4 figures, to appear on ApJ Lett
Redes de cooperación y aprendizaje: la Producción del mole en San Pedro Atocpan
Creators: name: Ortega, Rocío Rosales
name: Villanueva, Alma E. Cruz
Publisher: name: figshare
Year: 2018
Subjects: subject: Geography
subject: 160401 Economic Geography
subject: FOS: Social and economic geography
subject: 160499 Human Geography not elsewhere classified

description: (2016) en Marie-Christine Renard Hubert (coord.) Mercados y desarrollo local sustentable, Ed. CONACYT/COLOFÓN, pp. 305-328.
Rational Right Triangles of a Given Area
Creators: name: Chan, Stephanie
Publisher: name: arXiv
Year: 2017
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: Starting from any given rational-sided, right triangle, for example the $(3,4,5)$-triangle with area $6$, we use Euclidean geometry to show that there are infinitely many other rational-sided, right triangles of the same area. We show further that the set of all such triangles of a given area is finitely generated under our geometric construction. Such areas are known as "congruent numbers" and have a rich history in which all the results in this article have been proved and far more. Yet, as far as we can tell, this seems to be the first exploration using this kind of geometric technique.
description: 16 pages, 13 figures. To appear in the American Mathematical Monthly
StarHorse: A Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars
Creators: name: Queiroz, Anna B. A.
name: Anders, Friedrich
name: Santiago, Basílio X.
name: Chiappini, Cristina
name: Steinmetz, Matthias
name: Ponte, Marina Dal
name: Stassun, Keivan G.
name: da Costa, Luiz N.
name: Maia, Marcio A. G.
name: Beers, Timothy C.
name: Crestani, Juliana
name: Fernández-Trincado, J. G.
name: García-Hernández, Domingo Aníbal
name: Roman-Lopes, Alexandre
name: Zamora, Olga
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Understanding the formation and evolution of our Galaxy requires accurate distances, ages and chemistry for large populations of field stars. Here we present several updates to our spectro-photometric distance code, that can now also be used to estimate ages, masses, and extinctions for individual stars. Given a set of measured spectro-photometric parameters, we calculate the posterior probability distribution over a given grid of stellar evolutionary models, using flexible Galactic stellar-population priors. The code (called {\tt StarHorse}) can acommodate different observational datasets, prior options, partially missing data, and the inclusion of parallax information into the estimated probabilities. We validate the code using a variety of simulated stars as well as real stars with parameters determined from asteroseismology, eclipsing binaries, and isochrone fits to star clusters. Our main goal in this validation process is to test the applicability of the code to field stars with known {\it Gaia}-like parallaxes. The typical internal precision (obtained from realistic simulations of an APOGEE+Gaia-like sample) are $\simeq 8\%$ in distance, $\simeq 20\%$ in age,$\simeq 6\ %$ in mass, and $\simeq 0.04$ mag in $A_V$. The median external precision (derived from comparisons with earlier work for real stars) varies with the sample used, but lies in the range of $\simeq [0,2]\%$ for distances, $\simeq [12,31]\%$ for ages, $\simeq [4,12]\%$ for masses, and $\simeq 0.07$ mag for $A_V$. We provide StarHorse distances and extinctions for the APOGEE DR14, RAVE DR5, GES DR3 and GALAH DR1 catalogues.
description: 21 pages, 12 figures, accepted
Learning Continuous Face Representation with Explicit Functions
Creators: name: Zhang, Liping
name: Li, Weijun
name: Sun, Linjun
name: Yu, Lina
name: Ning, Xin
name: Dong, Xiaoli
name: Xu, Jian
name: Qin, Hong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: How to represent a face pattern? While it is presented in a continuous way in our visual system, computers often store and process the face image in a discrete manner with 2D arrays of pixels. In this study, we attempt to learn a continuous representation for face images with explicit functions. First, we propose an explicit model (EmFace) for human face representation in the form of a finite sum of mathematical terms, where each term is an analytic function element. Further, to estimate the unknown parameters of EmFace, a novel neural network, EmNet, is designed with an encoder-decoder structure and trained using the backpropagation algorithm, where the encoder is defined by a deep convolutional neural network and the decoder is an explicit mathematical expression of EmFace. Experimental results show that EmFace has a higher representation performance on faces with various expressions, postures, and other factors, compared to that of other methods. Furthermore, EmFace achieves reasonable performance on several face image processing tasks, including face image restoration, denoising, and transformation.
Martin Hunt: From Bruntingthorpe to Stalag 20a Thorn
Creators: name: Project Team, Their Finest Hour
Publisher: name: University of Oxford
Year: 2024
Subjects: classificationCode: 430304
subject: British history
classificationCode: 430308
subject: European history (excl. British, classical Greek and Roman)
classificationCode: 430316
subject: International history

description: Harold Martin Hunt was born in 1920. The exact date of his birth remains a mystery. His birthday was normally celebrated on October 21st, but his birth certificate says he was born on the 27th of October 1920. He was actually born in September, but his mother was seriously ill as a result of the birth and the whole process of registration was delayed.Harold Martin Hunt was baptised in St Mary's Church, Bruntingthorpe on November 28th, 1920, son of John and Elizabeth Hunt. Harold was always known as Martin, choosing to use his middle name rather than his first.Martin was one of fourteen children. He attended Bruntingthorpe School and later Lutterworth Central School. Martin spent time as a child riding horses on Bryce's Farm and generally doing little jobs. The money he earned was given to his mother.In September 1939, at the time of the War Work Census, he was living at Weir Road, Kibworth with the Spriggs family. He was already in the Leicestershire Regiment 1/5th Battalion. In September 1939, the 1/5th Battalion was based at Ratby Castle, Staindrop, County Durham and was part of the 148th Infantry Brigade. In April 1940, in preparation for the Norway Campaign, they were moved to Scotland. In mid-April 1940, they were landed near Narvik in Norway. After 10 days, the evacuation was ordered.Martin always said that the country was beautiful, but the expedition failed because they were ill-equipped compared to the German forces. On 23 April 1940, Martin Hunt was reported missing. This was reported to the War Office Casualty Section for the 24 hrs ending 12.00 on the 14 April 1940. He was casualty list number 204; his rank was Private, and his number was 4859069.Martin was captured along with many others and spent the next five years in a German prisoner-of-war camp. An official record shows M Hunt resided at Stalag 20a Thorn PODGORZ, Poland; his POW number was 4835. He spent his days working on the local farms.Stalag 20 was a complex of Polish forts near the town of Torun (Thorn) on the banks of the river Vistula. These were converted into prison camps. The British prisoners were in forts XI, XII, and XIII.When the Russian advance began in January 1945, the prisoners of war from Stalag 20 were marched westwards into Germany in harsh winter conditions with little food. Eventually, they were liberated by the Americans near Magdeburg.Martin died on 13 March 2009. The information above has been provided by his son, Robert Hunt.
Governance Dynamics: Textile, Talavera-Style Ceramic and Fireworks Production in Central México
Creators: name: Ortega, Rocío Rosales
name: Durán, Víctor Manuel Velázquez
name: Martínez, Jessica Mariela Tolentino
Publisher: name: figshare
Year: 2018
Subjects: subject: Geography
subject: 160401 Economic Geography
subject: FOS: Social and economic geography
subject: 160499 Human Geography not elsewhere classified

description: (2016) en G.Gómez y P.Knorringa (Eds.)Local Governance, Economic Development and Institutions, Palgrave Macmillan, pp. 155-181.
Phase transition and topology in 4d simplicial gravity
Creators: name: Bilke, S.
name: Burda, Z.
name: Krzywicki, A.
name: Petersson, B.
Publisher: name: arXiv
Year: 1996
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present data indicating that the recent evidence for the phase transition being of first order does not result from a breakdown of the ergodicity of the algorithm. We also present data showing that the thermodynamical limit of the model is independent of topology.
description: 3 latex pages + 4 ps fig. + espcrc2.sty. Talk presented at LATTICE(gravity)
Conditional generation of error syndromes in fault-tolerant error correction
Creators: name: Plenio, M. B.
name: Vedral, V.
name: Knight, P. L.
Publisher: name: arXiv
Year: 1996
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper we show how the fault--tolerant error correction scheme recently proposed by DiVincenzo and Shor may be improved. Our scheme, unlike the earlier one, can also deal with a single error that might occur {\em during} the gate operations that are required for the implementation of the error correction and not only in--between the gates and hence presents an improvement towards enabling error correction and with it the practical possibility of some more involved quantum computations, such as e.g. factorization of large numbers.
description: 4 pages