cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Near-field thermal upconversion and energy transfer through a Kerr medium : Theory
Creators: name: Khandekar, Chinmay
name: Rodriguez, Alejandro W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present an approach for achieving large Kerr $χ^{(3)}$--mediated thermal energy transfer at the nanoscale that exploits a general coupled-mode description of triply resonant, four-wave mixing processes. We analyze the efficiency of thermal upconversion and energy transfer from mid- to near-infrared wavelengths in planar geometries involving two slabs supporting far-apart surface plasmon polaritons and separated by a nonlinear $χ^{(3)}$ medium that is irradiated by externally incident light. We study multiple geometric and material configurations and different classes of interveening mediums---either bulk or nanostructured lattices of nanoparticles embedded in nonlinear materials---designed to resonantly enhance the interaction of the incident light with thermal slab resonances. We find that even when the entire system is in thermodynamic equilibrium (at room temperature) and under typical drive intensities $\sim\mathrm{W}/μ\mathrm{m}^2$, the resulting upconversion rates can approach and even exceed thermal flux rates achieved in typical symmetric and non-equilibrium configurations of vacuum-separated slabs. The proposed nonlinear scheme could potentially be exploited to achieve thermal cooling and refrigeration at the nanoscale, and to actively control heat transfer between materials with dramatically different resonant responses.
Fourier Analysis-based Iterative Combinatorial Auctions
Creators: name: Weissteiner, Jakob
name: Wendler, Chris
name: Seuken, Sven
name: Lubin, Ben
name: Püschel, Markus
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Computer and information sciences

description: Recent advances in Fourier analysis have brought new tools to efficiently represent and learn set functions. In this paper, we bring the power of Fourier analysis to the design of combinatorial auctions (CAs). The key idea is to approximate bidders' value functions using Fourier-sparse set functions, which can be computed using a relatively small number of queries. Since this number is still too large for practical CAs, we propose a new hybrid design: we first use neural networks (NNs) to learn bidders' values and then apply Fourier analysis to the learned representations. On a technical level, we formulate a Fourier transform-based winner determination problem and derive its mixed integer program formulation. Based on this, we devise an iterative CA that asks Fourier-based queries. We experimentally show that our hybrid ICA achieves higher efficiency than prior auction designs, leads to a fairer distribution of social welfare, and significantly reduces runtime. With this paper, we are the first to leverage Fourier analysis in CA design and lay the foundation for future work in this area. Our code is available on GitHub: https://github.com/marketdesignresearch/FA-based-ICAs.
Diagnosing and Preventing Instabilities in Recurrent Video Processing
Creators: name: Tanay, Thomas
name: Sootla, Aivar
name: Maggioni, Matteo
name: Dokania, Puneet K.
name: Torr, Philip
name: Leonardis, Ales
name: Slabaugh, Gregory
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Recurrent models are a popular choice for video enhancement tasks such as video denoising or super-resolution. In this work, we focus on their stability as dynamical systems and show that they tend to fail catastrophically at inference time on long video sequences. To address this issue, we (1) introduce a diagnostic tool which produces input sequences optimized to trigger instabilities and that can be interpreted as visualizations of temporal receptive fields, and (2) propose two approaches to enforce the stability of a model during training: constraining the spectral norm or constraining the stable rank of its convolutional layers. We then introduce Stable Rank Normalization for Convolutional layers (SRN-C), a new algorithm that enforces these constraints. Our experimental results suggest that SRN-C successfully enforces stability in recurrent video processing models without a significant performance loss.
Improved spatial separation of neutral molecules
Creators: name: Kienitz, Jens S.
name: Długołecki, Karol
name: Trippel, Sebastian
name: Küpper, Jochen
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We have developed and experimentally demonstrated an improved electrostatic deflector for the spatial separation of molecules according to their dipole-moment-to-mass ratio. The device features a very open structure that allows for significantly stronger electric fields as well as for stronger deflection without molecules crashing into the device itself. We have demonstrated its performance using the prototypical OCS molecule and we discuss opportunities regarding improved quantum-state-selectivity for complex molecules and the deflection of unpolar molecules.
description: 6 figures
Large-scale detector testing for the GAPS Si(Li) Tracker
Creators: name: Xiao, Mengjiao
name: Stoessl, Achim
name: Roach, Brandon
name: Gerrity, Cory
name: Bouche, Ian
name: Bridges, Gabriel
name: von Doetinchem, Philip
name: Hailey, Charles J.
name: Kraych, Derik
name: Katt, Anika
name: Law, Michael
name: Lowell, Alexander
name: Martinez, Evan
name: Perez, Kerstin
name: Reed, Maggie
name: Rodriguez, Chelsea
name: Saffold, Nathan
name: Stringfield, Ceaser
name: Weiner, Hershel
name: Yee, Kelsey
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Lithium-drifted silicon [Si(Li)] has been used for decades as an ionizing radiation detector in nuclear, particle, and astrophysical experiments, though such detectors have frequently been limited to small sizes (few cm$^2$) and cryogenic operating temperatures. The 10-cm-diameter Si(Li) detectors developed for the General Antiparticle Spectrometer (GAPS) balloon-borne dark matter experiment are novel particularly for their requirements of low cost, large sensitive area (~10 m$^2$ for the full 1440-detector array), high temperatures (near -40$\,^\circ$C), and energy resolution below 4 keV FWHM for 20--100-keV x-rays. Previous works have discussed the manufacturing, passivation, and small-scale testing of prototype GAPS Si(Li) detectors. Here we show for the first time the results from detailed characterization of over 1100 flight detectors, illustrating the consistent intrinsic low-noise performance of a large sample of GAPS detectors. This work demonstrates the feasibility of large-area and low-cost Si(Li) detector arrays for next-generation astrophysics and nuclear physics applications.
description: Updated to version accepted in IEEE Trans Nucl Sci. Minor changes to text, fixed plotting error on Fig. 5. Conclusions unchanged
Solution to the hyperon puzzle using dark matter
Creators: name: Del Popolo, Antonino
name: Deliyergiyev, Maksym
name: Delliou, Morgan Le
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In this paper, we studied the ``hyperon puzzle", a problem that nevertheless the large number of studies is still an open problem. The solution of this issue requires one or more mechanisms that could eventually provide the additional repulsion needed to make the EoS stiffer and, therefore, the value of $M_{\rm{max}, T}$ compatible with the current observational limits. In this paper we proposed that including dark matter (DM) admixed with ordinary matter in neutron stars (NSs), change the hydrostatic equilibrium and may explain the observed discrepancies, regardless to hyperon multi-body interactions, which seem to be unavoidable. We have studied how non-self-annihilating, and self-interacting, DM admixed with ordinary matter in NSs changes their inner structure, and discussed the mass-radius relations of such NSs. We considered DM particle masses of 1, 10, and 100 GeV, while taking into account a rich list of the DM interacting strengths, $y$. By analyzing the multidimensional parameter space, including several quantities like: a. the DM interacting strength, b. the DM particle mass as well as the quantity of DM in its interior, and c. the DM fraction, ${\rm f}_{DM}$, we put constraints in the parameter space ${\rm f}_{DM} - p^{\prime}_{\rm DM}/p^{\prime}_{\rm OM}$. Our bounds are sensitive to the recently observed NSs total masses.
description: 12 pp, 6 figs
Kinetic energy equipartition: a tool to characterize quantum thermalization
Creators: name: Destefani, Carlos F.
name: Oriols, Xavier
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Orthodox kinetic energy has, in fact, two hidden-variable components: one linked to the current (or Bohmian) velocity, and another linked to the osmotic velocity (or quantum potential), and which are respectively identified with phase and amplitude of the wavefunction. Inspired by Bohmian and Stochastic quantum mechanics, we address what happens to each of these two velocity components when the Orthodox kinetic energy thermalizes in closed systems, and how the pertinent weak values yield experimental information about them. We show that, after thermalization, the expectation values of both the (squared) current and osmotic velocities approach the same stationary value, that is, each of the Bohmian kinetic and quantum potential energies approaches half of the Orthodox kinetic energy. Such a `kinetic energy equipartition' is a novel signature of quantum thermalization that can empirically be tested in the laboratory, following a well-defined operational protocol as given by the expectation values of (squared) real and imaginary parts of the local-in-position weak value of the momentum, which are respectively related to the current and osmotic velocities. Thus, the kinetic energy equipartion presented here is independent on any ontological status given to these hidden variables, and it could be used as a novel element to characterize quantum thermalization in the laboratory, beyond the traditional use of expectation values linked to Hermitian operators. Numerical results for the nonequilibrium dynamics of a few-particle harmonic trap under random disorder are presented as illustration. And the advantages in using the center-of-mass frame of reference for dealing with systems with many indistinguishable particles are also discussed.
description: submitted on 02/May/23
Solving the Catalogue Cross-Match Problem in the Era of LSST: The Effect of Unresolved Contaminant Objects on Photometric Catalogues
Creators: name: Wilson, Tom J
name: Naylor, Tim
Publisher: name: Zenodo
Year: 2022

description: The Vera C. Rubin Observatory's LSST will be so crowded, even outside the Galactic plane, that standard cross-matching algorithms with other surveys will fail. In this poster I describe the effect of blending from contaminant sources on the astrometry and photometry of LSST and other catalogues (with WISE as a stand-in example for LSST crowding at its full 10-year depth), using Gaia and its extremely high precision data to reveal this hidden problem which causes up to 50% of Gaia-WISE matches to be missed, detailing how to overcome this problem with a Bayesian cross-match framework. I introduce the generic "Astrometric Uncertainty Function", discuss the use of the photometric information to break false match degeneracies, and briefly touch on additional benefits this new cross-match method has, such as the natural inclusion of proper motion when cross-matching datasets with no proper motion information and statistics on the level of flux contamination sources in each catalogue suffers.
description: {"references": ["Wilson & Naylor (2017, MNRAS, 468, 2517)", "Wilson & Naylor (2018, MNRAS, 473, 5570)", "Wilson & Naylor (2018, MNRAS, 481, 2148)", "Wilson (2022, RNAAS, 6, 60)", "Wilson (2022, RASTI, accepted)", "Sutherland & Saunders (1992, MNRAS, 259, 413)", "Wright et al. (2010, AJ, 140, 1868)"]}
Stable exponential cosmological solutions with zero variation of G in the Einstein-Gauss-Bonnet model with a Lambda-term
Creators: name: Ernazarov, K. K.
name: Ivashchuk, V. D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A D-dimensional gravitational model with a Gauss-Bonnet term and the cosmological term Lambda is considered. By assuming diagonal cosmological metrics, we find, for certain fine-tuned Lambda, a class of solutions with exponential time dependence of two scale factors, governed by two Hubble-like parameters H >0 and h < 0, corresponding to factor spaces of dimensions m > 3 and l > 1, respectively, with (m,l) non-equal to (6,6), (7,4), (9,3) and D = 1 + m + l. Any of these solutions describes an exponential expansion of 3-dimensional subspace with Hubble parameter H and zero variation of the effective gravitational constant G. We prove the stability of these solutions in a class of cosmological solutions with diagonal metrics.
description: 14 pages, 2 figures, LaTex., 2nd revised version, several words and phrases are changed or added, eq. (3.1) is modified, Remark on p. 4 is inserted. To be published in Eur. Phys. J. C. arXiv admin note: substantial text overlap with arXiv:1612.07178
Failure of Topological Invariants in Strongly Correlated Matter
Creators: name: Zhao, Jinchao
name: Mai, Peizhi
name: Bradlyn, Barry
name: Phillips, Philip
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show exactly that standard `invariants' advocated to define topology for non-interacting systems deviate strongly from the Hall conductance whenever the excitation spectrum contains zeros of the single-particle Green function, $G$, as in general strongly correlated systems. Namely, we show that if the chemical potential sits atop the valence band, the `invariant' changes without even accessing the conduction band but by simply traversing the band of zeros that might lie between the two bands. Since such a process does not change the many-body ground state, the Hall conductance remains fixed. This disconnect with the Hall conductance arises from the replacement of the Hamiltonian, $h(\bb k)$, with $G^{-1}$ in the current operator, thereby laying plain why perturbative arguments fail.
Thermal transport and quasi-normal modes in Gauss-Bonnet-axions theory
Creators: name: Kuang, Xiao-Mei
name: Wu, Jian-Pin
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We obtain the black brane solution in arbitrary dimensional Gauss-Bonnet-axions (GBA) gravity theory. And then the thermal conductivity of the boundary theory dual to this neutral black brane is explored. We find that the momentum dissipation suppresses the DC thermal conductivity while it is enhanced by larger GB parameter. The analytical and numerical results of DC thermal conductivity match very well. Also we study the effect of the momentum dissipation and the GB coupling on the AC thermal conductivity and fit the results by Drude-like behavior for low frequency. Finally, we analytical compute the quasi-normal modes (QNM) frequency of the perturbative master field in large dimensions limit. Our analytical QNM frequencies agree well with the numerical results in large enough finite dimensions.
description: 12 pages, 6 figures; minor revision, references added; published version
A numerically efficient output-only system-identification framework for stochastically forced self-sustained oscillators
Creators: name: Lee, Minwoo
name: Kim, Kyu Tae
name: Park, Jongho
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics
subject: 90C53, 90C56, 90C26, 65Z05

description: Self-sustained oscillations are ubiquitous in nature and engineering. In this paper, we propose a novel output-only system-identification framework for identifying the system parameters of a self-sustained oscillator affected by Gaussian white noise. A Langevin model that characterizes the self-sustained oscillator is postulated, and the corresponding Fokker--Planck equation is derived from stochastic averaging. From the drift and diffusion terms of the Fokker--Planck equation, unknown parameters of the system are identified. We develop a numerically efficient algorithm for enhancing the accuracy of parameter identification. In particular, a modified Levenberg--Marquardt optimization algorithm tailored to output-only system identification is introduced. The proposed framework is demonstrated on both numerical and experimental oscillators with varying system parameters that develop into self-sustained oscillations. The results show that the computational cost required for performing the system identification is dramatically reduced by using the proposed framework. Also, system parameters that were difficult to be extracted with the existing method could be efficiently computed with the system identification method developed in this study. Pertaining to the robustness and computational efficiency of the presented framework, this study can contribute to an accurate and fast diagnosis of dynamical systems under stochastic forcing.
description: 17 pages, 10 figures
Tuning the collective decay of two entangled emitters by means of a nearby surface
Creators: name: Palacino, R.
name: Passante, R.
name: Rizzuto, L.
name: Barcellona, P.
name: Buhmann, S. Y.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the radiative properties of a system of two identical correlated atoms interacting with the electromagnetic field in its vacuum state in the presence of a generic dielectric environment. We suppose that the two emitters are prepared in a symmetric or antisymmetric superposition of one ground state and one excited state and we evaluate the transition rate to the collective ground state, showing distinctive cooperative radiative features. Using a macroscopic quantum electrodynamics approach to describe the electromagnetic field, we first obtain an analytical expression for the decay rate of the two entangled two-level atoms in terms of the Green's tensor of the generic external environment. We then investigate the emission process when both atoms are in free space and subsequently when a perfectly reflecting mirror is present, showing how the boundary affects the physical features of the superradiant and subradiant emission by the two coupled emitters. The possibility to control and tailor radiative processes is also discussed.
description: 11 pages, 8 figures
Sustained turbulence and magnetic energy in non-rotating shear flows
Creators: name: Nauman, Farrukh
name: Blackman, Eric G.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: From numerical simulations, we show that non-rotating magnetohydrodynamic shear flows are unstable to finite amplitude velocity perturbations and become turbulent, leading to the growth and sustenance of magnetic energy, including large scale fields. This supports the concept that sustained magnetic energy from turbulence is independent of the driving mechanism for large enough magnetic Reynolds numbers.
description: 6 pages, 9 figures, accepted by PRE
Magic-angle helical trilayer graphene
Creators: name: Devakul, Trithep
name: Ledwith, Patrick J.
name: Xia, Li-Qiao
name: Uri, Aviram
name: de la Barrera, Sergio
name: Jarillo-Herrero, Pablo
name: Fu, Liang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose helical trilayer graphene (HTG), a helical structure featuring identical rotation angles $θ\approx 1.5^\circ$ between three consecutive layers of graphene, as a unique and experimentally accessible platform for realizing exotic correlated topological states of matter. While nominally forming a supermoiré (or moiré-of-moiré) structure, we show that HTG locally relaxes into large regions of a periodic single-moiré structure in which $C_{2z}$ is broken, giving rise to flat topological bands carrying valley-Chern numbers $C=\pm(1,-2)$. These bands feature near-ideal quantum geometry and are isolated from remote bands by a large gap $E_{\mathrm{gap}}\sim 100$ meV, making HTG a promising platform for experimental realization of correlated topological states such as integer and fractional quantum anomalous Hall states in $C=1$ and $2$ bands.
Tambour à deux peaux clouées sur cadre avec chapelet de grelots. Vue générale de face
Creators: name: Musée National Des Arts Et Traditions Populaires (Paris)
name: Centre D'ethnologie Française
Publisher: name: École des Hautes Études en Sciences Sociales; Institut  interdisciplinaire d'anthropologie du contemporain (Paris); Laboratoire d'anthropologie et d'histoire de l'institution de la culture (Paris)
Year: 2022

Abstract
title: Trauerfeier für Hans W. Löw-Stierlin, 11. Oktober 1897-9. November 1969, in der Kirche Stallikon am 12. November
title: Hans W. Löw-Stierlin, 1897-1969
titleType: AlternativeTitle
Creators: name: (:Unkn) Unknown
Publisher: name: Zentralbibliothek Zürich
Year: 1969
Subjects: subject: 920 Biografien, Genealogie, Insignien
subject: Nachruf
subject: Löw-Stierlin, Hans W.
subject: Oberer Hauenstein
subject: Langenbruck (Basel-Landschaft)

description: Enthält: Mein Lebenslauf; Die Angehörigen fügen bei; Ansprache von Pfarrer Emanuel Kellerhans; Gedenkworte von Pfarrer Hans Leuenberger; Ein Mann der Mission und der Kirche von Kurt Furthmüller
Szegő kernel asymptotics on some non-compact complete CR manifolds
Creators: name: Hsiao, Chin-Yu
name: Marinescu, George
name: Wang, Huan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Complex Variables (math.CV)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We establish Szegő kernel asymptotic expansions on non-compact strictly pseudoconvex complete CR manifolds with transversal CR $\mathbb{R}$-action under certain natural geometric conditions.
Shared urbanism: Big data on accommodation sharing in urban Australia
Creators: name: Sarkar, Somwrita
name: Gurran, Nicole
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computers and Society (cs.CY)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: As affordability pressures and tight rental markets in global cities mount, online shared accommodation sites proliferate. Home sharing arrangements present dilemmas for planning that aims to improve health and safety standards, while supporting positives such as the usage of dormant stock and the relieving of rental pressures on middle/lower income earners. Currently, no formal data exists on this internationally growing trend. Here, we present a first quantitative glance on shared accommodation practices across all major urban centers of Australia enabled via collection and analysis of thousands of online listings. We examine, countrywide, the spatial and short time scale temporal characteristics of this market, along with preliminary analysis on rents, dwelling types and other characteristics. Findings have implications for housing policy makers and planning practitioners seeking to monitor and respond to housing policy and affordability pressures in formal and informal housing markets.
description: 19 Pages
Ram pressure stripping in the EAGLE simulation
Creators: name: Kulier, Andrea
name: Poggianti, Bianca
name: Tonnesen, Stephanie
name: Smith, Rory
name: Ignesti, Alessandro
name: Akerman, Nina
name: Marasco, Antonino
name: Vulcani, Benedetta
name: Moretti, Alessia
name: Wolter, Anna
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Ram pressure stripping of satellite galaxies is thought to be a ubiquitous process in galaxy clusters, and a growing number of observations reveal satellites at different stages of stripping. However, in order to determine the fate of any individual galaxy, we turn to predictions from either simulations or analytic models. It is not well-determined whether simulations and analytic models agree in their predictions, nor the causes of disagreement. Here we investigate ram pressure stripping in the reference EAGLE hydrodynamical cosmological simulation, and compare the results to predictions from analytic models. We track the evolution of galaxies with stellar mass $M_{*} > 10^{9} \, \mathrm{M_{\odot}}$ and initial bound gas mass $M_{\mathrm{gas}} > 10^{9} \, \mathrm{M_{\odot}}$ that fall into galaxy clusters ($M_{\mathrm{200c}} > 10^{14} \, \mathrm{M_{\odot}}$) between $z = 0.27$ and $z = 0$. We divide each galaxy into its neutral gas disk and hot ionized gas halo and compare the evolution of the stripped gas fraction in the simulation to that predicted by analytic formulations for the two gas phases, as well as to a toy model that computes the motions of gas particles under the combined effects of gravity and a spatially uniform ram pressure. We find that the analytic models generally underpredict the stripping rate of neutral gas and overpredict that of ionized gas, with significant scatter between the model and simulation stripping timescales. This is due to opposing physical effects: the enhancement of ram pressure stripping by stellar feedback, and the suppression of stripping by the compaction of galactic gas.
description: 28 pages, 12 figures, plus 1 appendix. Version accepted to ApJ
Disclosure Risk from Homogeneity Attack in Differentially Private Frequency Distribution
Creators: name: Liu, Fang
name: Zhao, Xingyuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Differential privacy (DP) provides a robust model to achieve privacy guarantees for released information. We examine the protection potency of sanitized multi-dimensional frequency distributions via DP randomization mechanisms against homogeneity attack (HA). HA allows adversaries to obtain the exact values on sensitive attributes for their targets without having to identify them from the released data. We propose measures for disclosure risk from HA and derive closed-form relationships between the privacy loss parameters in DP and the disclosure risk from HA. The availability of the closed-form relationships assists understanding the abstract concepts of DP and privacy loss parameters by putting them in the context of a concrete privacy attack and offers a perspective for choosing privacy loss parameters when employing DP mechanisms in information sanitization and release in practice. We apply the closed-form mathematical relationships in real-life datasets to demonstrate the assessment of disclosure risk due to HA on differentially private sanitized frequency distributions at various privacy loss parameters.
COVID-19 Working Paper: Food Insecurity During the First Year of the COVID-19 Pandemic in Four African Countries
Creators: name: Bloem, Jeffrey
name: Michler, Jeffrey
name: Josephson, Anna
name: Rudin-Rush, Lorin
name: Bloem, Jeffrey
name: Michler, Jeffrey
name: Josephson, Anna
name: Rudin-Rush, Lorin
Publisher: name: Unknown
Year: 2022
Subjects: subject: Consumer/Household Economics
subject: Demand and Price Analysis
subject: Financial Economics
subject: Food Security and Poverty
subject: Health Economics and Policy
subject: Institutional and Behavioral Economics
subject: Political Economy
subject: Production Economics
subject: Public Economics
subject: Coronavirus
subject: COVID-19 pandemic
subject: food security
subject: rural food security
subject: urban food security
subject: markets
subject: gender
subject: sub-Saharan Africa
subject: World Bank
subject: Burkina Faso
subject: Ethiopia, Malawi
subject: Nigeria

description: This report analyzes food security in the year after the onset of the Coronavirus (COVID-19) pandemic in four African countries. Using household-level data collected by the World Bank, this report describes differences in food security over time during the pandemic between rural and urban areas as well as between female- and male-headed households in Burkina Faso, Ethiopia, Malawi, and Nigeria. A sharp increase in food insecurity is observed during the early months of the pandemic before a gradual decline. Additionally, findings show a larger increase in food insecurity in rural areas relative to urban areas within each of these countries. Finally, no systemic difference in food insecurity is found between female-headed and male-headed households.
Exploring the gravity sector of emergent higher-spin gravity: effective action and a solution
Creators: name: Fredenhagen, Stefan
name: Steinacker, Harold C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We elaborate the description of the semi-classical gravity sector of Yang-Mills matrix models on a covariant quantum FLRW background. The basic geometric structure is a frame, which arises from the Poisson structure on an underlying $S^2$ bundle over space-time. The equations of motion for the associated Weitzenböck torsion obtained in arXiv:2002.02742 are rewritten in the form of Yang-Mills-type equations for the frame. An effective action is found which reproduces these equations of motion, which contains an Einstein-Hilbert term coupled to a dilaton, an axion and a Maxwell-type term for the dynamical frame. An explicit rotationally invariant solution is found, which describes a gravitational field coupled to the dilaton.
description: 39 pages, v2: minor issues fixed, conclusion unchanged V3: Appendix E.1 corrected, no change of results or conclusions
Ingo Lütjens, Archsum LA 65 (Melenknop), Schichtpaket A. Eine Siedlung der jüngeren vorrömi­schen Eisen- bis frühen römischen Kaiserzeit
Creators: name: Martens, Jes
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2023

description: Rezension zu: Ingo Lütjens, Archsum LA 65 (Melenknop), Schichtpaket A. Eine Siedlung der jüngeren vorrömi­schen Eisen- bis frühen römischen Kaiserzeit. Universitätsforschungen zur Prähistorischen Archäo­logie Band 149. Verlag Dr. Rudolf Habelt, Bonn 2008. ISBN 978-3-7749-3449-8. 2 volumes wich 574 pages, 243 figures, 10 plates and a CD-Rom
description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 89 2011(2013)
Germanium wafers for strained quantum wells with low disorder
Creators: name: Stehouwer, Lucas E. A.
name: Tosato, Alberto
name: Esposti, Davide Degli
name: Costa, Davide
name: Veldhorst, Menno
name: Sammak, Amir
name: Scappucci, Giordano
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We grow strained Ge/SiGe heterostructures by reduced-pressure chemical vapor deposition on 100 mm Ge wafers. The use of Ge wafers as substrates for epitaxy enables high-quality Ge-rich SiGe strain-relaxed buffers with a threading dislocation density of (6$\pm$1)$\times$10$^5$ cm$^{-2}$, nearly an order of magnitude improvement compared to control strain-relaxed buffers on Si wafers. The associated reduction in short-range scattering allows for a drastic improvement of the disorder properties of the two-dimensional hole gas, measured in several Ge/SiGe heterostructure field-effect transistors. We measure an average low percolation density of (1.22$\pm$0.03)$\times$10$^{10}$ cm$^{-2}$, and an average maximum mobility of (3.4$\pm$0.1)$\times$10$^{6}$ cm$^2$/Vs and quantum mobility of (8.4$\pm$0.5)$\times$10$^{4}$ cm$^2$/Vs when the hole density in the quantum well is saturated to (1.65$\pm$0.02)$\times$10$^{11}$ cm$^{-2}$. We anticipate immediate application of these heterostructures for next-generation, higher-performance Ge spin-qubits and their integration into larger quantum processors.
High bandwidth laser-frequency-locking for wideband noise suppression
Creators: name: Jing, Mingyong
name: Zhang, Peng
name: Yuan, Shaoxin
name: Zhang, Linjie
name: Xiao, Liantuan
name: Jia, Suotang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Instrumentation and Detectors (physics.ins-det)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Ultra-low frequency noise lasers have been widely used in laser-based experiments. Most narrow-linewidth lasers are implemented by actively suppressing their frequency noise through a frequency noise servo loop (FNSL). The loop bandwidths (LBW) of FNSLs are currently below megahertz, which is gradually tricky to meet application requirements, especially for wideband quantum sensing experiments. This article has experimentally implemented an FNSL with loop-delay-limited 3.5 MHz LBW, which is an order higher than the usual FNSLs. Using this FNSL, we achieved 70 dB laser frequency noise suppression over 100 kHz Fourier frequency range. This technology has broad applications in vast fields where wideband laser frequency noise suppression is inevitable.
Webinar PSLH ITB Pengelolaan air tanah berkelanjutan
Creators: name: Irawan, Dasapta Erwin
name: Puradimaja, Deny Juanda
Publisher: name: Zenodo
Year: 2020
Subjects: pslh
pusat studi lingkungan hidup
itb
institut teknologi bandung
pembangunan berkelanjutan
pengelolaan air tanah
groundwater
hidrogeologi

description: Materi ini disampaikan pada acara Webinar PSLH 12 Juni 2020.
Germania magna - Ein neuer Blick auf eine alte Karte
Creators: name: Nüsse, Hans-Jörg
name: Marx, Christian
name: Lelgemann, Dieter
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2023

description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 89 2011(2013)
Awareness and Metacognitive actor
Creators: name: ELKETANI, Samyr
Publisher: name: figshare
Year: 2022
Subjects: subject: Education
subject: 130101 Continuing and Community Education
subject: FOS: Educational sciences
subject: 130102 Early Childhood Education (excl. Maori)
subject: 140204 Economics of Education
subject: FOS: Economics and business
subject: 130199 Education systems not elsewhere classified
subject: 130103 Higher Education
subject: 130106 Secondary Education

description: The learner’s awareness of his cognitive processes and his control over the various metacognitive components is the basis of methodological competencies, as the priority of educational systems seeking to improve the level of effectiveness of strategic choices and improving learning outcomes with an economy in effort and time. Our analytical approach concluded that the learner's awareness of his cognitive processes and the knowledge associated with the tasks and situations that contain cognitive activity are metacognitive components as the conversation about metacognitive awareness is not possible except in the presence of the same learner as a metacognitive actor capable of various intellectual processes used in learning situations. This relationship suggests a future in which educational practices can best support the lifelong learning and sustainable development. Therefore, any strategic choice, whether at the level of treatment or at the level of execution, is a reflection of the learner's awareness of his cognitive processes in the various stages of performance. Metacognitive is a conscious process that refers to the knowledge of what the individual knows and the states of knowledge in the relationship with associated factors then monitoring and organizing them consciously, dynamically and intentionally, in order to improve the performance of achievement paths effectively, in order to build a new knowledge directed towards the future, allowing a person to meet his cognitive and socio-emotional needs in relation to the other and the world. In this research, a number of related concepts will bereviewed in view of their role in learning and knowledge building, especially with the widening gap between educational field practice and the true needs of learners. It also aims to improve the learning outcomes by providing the learner with motivational, emotional, strategic and cognitive skills in order to achieve personal goals intrinsically and externally.
Structural Dynamics Descriptors for Metal Halide Perovskites
Creators: name: Liang, Xia
name: Klarbring, Johan
name: Baldwin, William
name: Li, Zhenzhu
name: Csányi, Gábor
name: Walsh, Aron
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Metal halide perovskites have shown extraordinary performance in solar energy conversion technologies. They have been classified as "soft semiconductors" due to their flexible corner-sharing octahedral networks and polymorphous nature. Understanding the local and average structures continues to be challenging for both modelling and experiments. Here, we report the quantitative analysis of structural dynamics in time and space from molecular dynamics simulations of perovskite crystals. The compact descriptors provided cover a wide variety of structural properties, including octahedral tilting and distortion, local lattice parameters, molecular orientations, as well as their spatial correlation. To validate our methods, we have trained a machine learning force field (MLFF) for methylammonium lead bromide (CH$_3$NH$_3$PbBr$_3$) using an on-the-fly training approach with Gaussian process regression. The known stable phases are reproduced and we find an additional symmetry-breaking effect in the cubic and tetragonal phases close to the phase transition temperature. To test the implementation for large trajectories, we also apply it to 69,120 atom simulations for CsPbI$_3$ based on an MLFF developed using the atomic cluster expansion formalism. The structural dynamics descriptors and Python toolkit are general to perovskites and readily transferable to more complex compositions.
description: 10 figures
Le ricette del passato
Creators: name: Orsini, Francesco
name: Blasioli, Sonia
name: Pistillo, Alessandro
name: Brussi, Greta
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2022
Subjects: AGR/04 Orticoltura e floricoltura

description: Questo libro contiene una raccolta di ricette della tradizione bolognese elaborato da studenti delle scuole della città.
Moment categories and operads
Creators: name: Berger, Clemens
Publisher: name: arXiv
Year: 2021
Subjects: subject: Category Theory (math.CT)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 18A32, 18M60 (Primary) 18M85, 18N70 (Secondary)

description: A moment category is endowed with a distinguished set of split idempotents, called moments, which can be transported along morphisms. Equivalently, a moment category is a category with an active/inert factorisation system fulfilling two simple axioms. These axioms imply that the moments of a fixed object form a monoid, actually a left regular band. Each locally finite unital moment category defines a specific type of operad which records the combinatorics of partitioning moments into elementary ones. In this way the notions of symmetric, non-symmetric and $n$-operad correspond to unital moment structures on $Γ$, $Δ$ and $Θ_n$ respectively. There is an analog of the plus construction of Baez-Dolan taking a unital moment category $\mathbb{C}$ to a unital hypermoment category $\mathbb{C}^+$. Under this construction, $\mathbb{C}$-operads get identified with $\mathbb{C}^+$-monoids, i.e. presheaves on $\mathbb{C}^+$ satisfying strict Segal conditions. We show that the plus construction of Segal's category $Γ$ embeds into the dendroidal category $Ω$ of Moerdijk-Weiss.
description: Final version
NOMU: Neural Optimization-based Model Uncertainty
Creators: name: Heiss, Jakob
name: Weissteiner, Jakob
name: Wutte, Hanna
name: Seuken, Sven
name: Teichmann, Josef
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We study methods for estimating model uncertainty for neural networks (NNs) in regression. To isolate the effect of model uncertainty, we focus on a noiseless setting with scarce training data. We introduce five important desiderata regarding model uncertainty that any method should satisfy. However, we find that established benchmarks often fail to reliably capture some of these desiderata, even those that are required by Bayesian theory. To address this, we introduce a new approach for capturing model uncertainty for NNs, which we call Neural Optimization-based Model Uncertainty (NOMU). The main idea of NOMU is to design a network architecture consisting of two connected sub-NNs, one for model prediction and one for model uncertainty, and to train it using a carefully-designed loss function. Importantly, our design enforces that NOMU satisfies our five desiderata. Due to its modular architecture, NOMU can provide model uncertainty for any given (previously trained) NN if given access to its training data. We evaluate NOMU in various regressions tasks and noiseless Bayesian optimization (BO) with costly evaluations. In regression, NOMU performs at least as well as state-of-the-art methods. In BO, NOMU even outperforms all considered benchmarks.
description: 9 pages + appendix
Emergent Gravity in Spaces of Constant Curvature
Creators: name: Alvarez, Orlando
name: Haddad, Matthew
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In physical theories where the energy (action) is localized near a submanifold of a constant curvature space, there is a universal expression for the energy (or the action). We derive a multipole expansion for the energy that has a finite number of terms, and depends on intrinsic geometric invariants of the submanifold and extrinsic invariants of the embedding of the submanifold. This is the second of a pair of articles in which we try to develop a theory of emergent gravity arising from the embedding of a submanifold into an ambient space equipped with a quantum field theory. Our theoretical method requires a generalization of a formula due to by Hermann Weyl. While the first paper discussed the framework in Euclidean (Minkowski) space, here we discuss how this framework generalizes to spaces of constant sectional curvature. We focus primarily on anti de Sitter space. We then discuss how such a theory can give rise to a cosmological constant and Planck mass that are within reasonable bounds of the experimental values.
description: 20 pages, 3 figures
Role of Mixup in Topological Persistence Based Knowledge Distillation for Wearable Sensor Data
Creators: name: Jeon, Eun Som
name: Choi, Hongjun
name: Buman, Matthew P.
name: Turaga, Pavan
Publisher: name: arXiv
Year: 2025
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The analysis of wearable sensor data has enabled many successes in several applications. To represent the high-sampling rate time-series with sufficient detail, the use of topological data analysis (TDA) has been considered, and it is found that TDA can complement other time-series features. Nonetheless, due to the large time consumption and high computational resource requirements of extracting topological features through TDA, it is difficult to deploy topological knowledge in various applications. To tackle this problem, knowledge distillation (KD) can be adopted, which is a technique facilitating model compression and transfer learning to generate a smaller model by transferring knowledge from a larger network. By leveraging multiple teachers in KD, both time-series and topological features can be transferred, and finally, a superior student using only time-series data is distilled. On the other hand, mixup has been popularly used as a robust data augmentation technique to enhance model performance during training. Mixup and KD employ similar learning strategies. In KD, the student model learns from the smoothed distribution generated by the teacher model, while mixup creates smoothed labels by blending two labels. Hence, this common smoothness serves as the connecting link that establishes a connection between these two methods. In this paper, we analyze the role of mixup in KD with time-series as well as topological persistence, employing multiple teachers. We present a comprehensive analysis of various methods in KD and mixup on wearable sensor data.
description: IEEE Sensors Journal (2024)
Quantum marginals, faces, and coatoms
Creators: name: Weis, Stephan
name: Gouveia, João
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Optimization and Control (math.OC)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 81P45, 94A15, 90C22, 52A20

description: Many problems of quantum information theory rely on the set of quantum marginals. A precise knowledge of the faces of this convex set is necessary, for example, in the reconstruction of states from their marginals or in the evaluation of complexity measures of many-body systems. Yet, even the two-body marginals of just three qubits were only described in part. Here, we propose an experimental method to search for the coatoms in the lattice of exposed faces of the convex set of quantum marginals. The method is based on sampling from the extreme points of the dual spectrahedron. We provide an algebraic certificate of correctness, employing ground projectors of local Hamiltonians. Using this method, we present an explicit family of coatoms of rank five in the lattice of ground projectors of two-local three-qubit Hamiltonians (the rank is always six for bits). This family describes a family of coatoms in the lattice of exposed faces of the convex set of two-body marginals of three qubits. Besides introducing the experimental method, we show that the support sets of probability distributions that factor are the ground projectors of frustration-free Hamiltonians in the commutative setting. We also discuss nonexposed points of the set of marginals.
description: The Version of Record of this article is S. Weis and J. Gouveia, "The face lattice of the set of reduced density matrices and its coatoms", Information Geometry, 2023. A full-text view-only version is available online at https://rdcu.be/c7b2s