cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Structure of inactive states of a binary Lennard-Jones mixture
Creators: name: Coslovich, Daniele
name: Jack, Robert L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study the structure of inactive states in a prototypical model glass, the Kob-Andersen binary Lennard-Jones mixture. These inactive states are obtained by transition path sampling and are at dynamical phase coexistence with an active equilibrium state. Configurations in the inactive states are kinetically stable and are located in deeper basins of the energy landscape than their active counterparts. By analyzing trajectory-to-trajectory fluctuations within the inactive state, we assess correlations between kinetic stability, energy and other structural properties. We show that measures of local order associated to stable local packings and bond-orientational order are weakly correlated with energy and kinetic stability. We discuss what kinds of structural measurement might capture the relevant dynamical features of the inactive state.
description: 18 pages, 9 figures, contribution to the special issue "The role of structure in glassy and jammed systems". Data underlying this paper are available at http://doi.org/10.15125/BATH-00209
Dynamical Tides Reexpressed
Creators: name: Kushnir, Doron
name: Zaldarriaga, Matias
name: Kollmeier, Juna A.
name: Waldman, Roni
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Zahn (1975) first put forward and calculated in detail the torque experienced by stars in a close binary systems due to dynamical tides. His widely used formula for stars with radiative envelopes and convective cores is expressed in terms of the stellar radius, even though the torque is actually being applied to the convective core at the core radius. This results in a large prefactor, which is very sensitive to the global properties of the star, that multiplies the torque. This large factor is compensated by a very small multiplicative factor, $E_{2}$. Although this is mathematically accurate, depending on the application this can lead to significant errors. The problem is even more severe, since the calculation of $E_{2}$ itself is non-trivial, and different authors have obtained inconsistent values of $E_{2}$. Moreover, many codes (e.g. BSE, StarTrack, MESA) interpolate (and sometimes extrapolate) a fit of $E_{2}$ values to the stellar mass, often in regimes where this is not sound practice. We express the torque in an alternate form, cast in terms of parameters at the envelope-core boundary and a dimensionless coefficient, $β_{2}$. Previous attempts to express the torque in such a form are either missing an important factor, which depends on the density profile of the star, or are not easy to implement. We show that $β_{2}$ is almost independent of the properties of the star and its value is approximately unity. Our formula for the torque is simple to implement and avoids the difficulties associated with the classic expression.
description: 7 pages, 2 figures. The results of Claret & Cunha in Figure 1 were corrected, and are now consistent with the other stellar models in the literature. Other results and conclusions are unchanged
Small separations in red-giant stars: Quest for late evolution signatures using asteroseismology
Creators: name: Ferreira, Maria Inês
name: Bossini, Diego
name: Neitzel, Andreas W.
Publisher: name: Zenodo
Year: 2024

description: This work is dedicated to the exploration of the small frequency separation in red-giant stars, an asteroseismic parameter that comes from the analysis of the oscillation spectra of the stars. Our study focuses on two evolutionary phases of red-giant stars: the red-giant branch (RGB) and the red clump (RC); while in the former the core-helium burning did not occur yet, in the latter it is active. These two phases overlap in the HRD, making it difficult to discern between them. It is possible to partially solve this issue using the period spacing of the gravity modes, which, however, requires high-quality data to be measured. In order to understand the potential of the poorly studied small frequency separation in distinguishing between RGB and RC stars, an ML tool was applied and several tests performed on synthetic stellar samples using classic (effective temperature, luminosity and metallicity) and asteroseismic (large and small frequency separations as well as the frequency at maximum power) parameters. The first such test consists in using different input parameters (with and without the small separation) and comparing the performance metrics, namely, the accuracy, the informedness and the AUC score. The second test was done using the feature importance based on the method applied. We report that, from the four input feature groups (with the small separation), there are two in which the small frequency separation has the highest impact on the stellar classification.
Homoclinic points of 2-D and 4-D maps via the Parametrization Method
Creators: name: Anastassiou, Stavros
name: Bountis, Tassos
name: Bäcker, Arnd
Publisher: name: arXiv
Year: 2016
Subjects: subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: An interesting problem in solid state physics is to compute discrete breather solutions in $\mathcal{N}$ coupled 1--dimensional Hamiltonian particle chains and investigate the richness of their interactions. One way to do this is to compute the homoclinic intersections of invariant manifolds of a saddle point located at the origin of a class of $2\mathcal{N}$--dimensional invertible maps. In this paper we apply the parametrization method to express these manifolds analytically as series expansions and compute their intersections numerically to high precision. We first carry out this procedure for a 2--dimensional (2--D) family of generalized Henon maps ($\mathcal{N}$=1), prove the existence of a hyperbolic set in the non-dissipative case and show that it is directly connected to the existence of a homoclinic orbit at the origin. Introducing dissipation we demonstrate that a homoclinic tangency occurs beyond which the homoclinic intersection disappears. Proceeding to $\mathcal{N}=2$, we use the same approach to determine the homoclinic intersections of the invariant manifolds of a saddle point at the origin of a 4--D map consisting of two coupled 2--D cubic Hénon maps. In dependence of the coupling the homoclinic intersection is determined, which ceases to exist once a certain amount of dissipation is present. We discuss an application of our results to the study of discrete breathers in two linearly coupled 1--dimensional particle chains with nearest--neighbor interactions and a Klein--Gordon on site potential.
description: 24 pages, 10 figures, videos can be found at https://comp-phys.tu-dresden.de/supp/
Resonance fluorescence from an artificial atom in squeezed vacuum
Creators: name: Toyli, D. M.
name: Eddins, A. W.
name: Boutin, S.
name: Puri, S.
name: Hover, D.
name: Bolkhovsky, V.
name: Oliver, W. D.
name: Blais, A.
name: Siddiqi, I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present an experimental realization of resonance fluorescence in squeezed vacuum. We strongly couple microwave-frequency squeezed light to a superconducting artificial atom and detect the resulting fluorescence with high resolution enabled by a broadband traveling-wave parametric amplifier. We investigate the fluorescence spectra in the weak and strong driving regimes, observing up to 3.1 dB of reduction of the fluorescence linewidth below the ordinary vacuum level and a dramatic dependence of the Mollow triplet spectrum on the relative phase of the driving and squeezed vacuum fields. Our results are in excellent agreement with predictions for spectra produced by a two-level atom in squeezed vacuum [Phys. Rev. Lett. \textbf{58}, 2539-2542 (1987)], demonstrating that resonance fluorescence offers a resource-efficient means to characterize squeezing in cryogenic environments.
DILEMA Kampanye vaksin, Hak bayi yang dilindungi undang-undang
Creators: name: Rahman, Ferry
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: hak bayi dilindungi undang-undang
subject: vaksin

description: membahas mengenai hambatan-hambatan dalam pemberian vaksin Measles Rubela serta dasar hukum kewajiban pemberian vaksin dasar bagi anak
Ocean-Cryosphere Exchanges in Antarctica: Impacts on the Climate and the Earth System
Creators: name: Meijers, Andrew
name: Bearzotti, Chiara
Publisher: name: Zenodo
Year: 2023

description: This presentation was given by Andrew Meijers at the session: Marine Data, Information and Knowledge for EU Green Deal and Climate Change (panel discussion) in the afternoon of 27 June 2023 starting at 14:30 CEST. Watch this event on YouTube: https://www.youtube.com/watch?v=XyiseZQTMy0
What are the quality challenges regarding comparability considerations of advanced therapy medicinal products?
Creators: name: Andrieu Véronique
name: Gennet Eloïse
name: Véran Julie
name: Michael, Morrison
name: Sabatier Florence
name: Aurélie, Mahalatchimy
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the 2022 Conference of the European Association of Health Law (EAHL) in Ghent.
description: Also available: https://shs.hal.science/halshs-03780293v1
Improving access to Innovative medicines: proposals from national authorities to revise the European legislation
Creators: name: Aurélie, Mahalatchimy
name: Lanson Florence
name: Bartos Blanka
name: Taboulet Florence
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the 2022 European Society of Gene & Cell Therapy Congress in Edinburgh.
description: Also available: https://shs.hal.science/halshs-03901248v1
Large-scale Minimax Optimization Problems
Creators: name: Hajizadeh, Saeid
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Minimax optimization has long been an important subject in optimization with widespread applications in robust optimization, game theory, and, more recently, in reinforcement learning and Generative Adversarial Networks (GANs). The recent applications of minimax optimization often involve objective functions that are neither convex in the minimization variable nor concave in the maximization variable which makes the convergence of algorithms harder to attain. Moreover, the huge scale of these problems renders first-order methods, i.e. methods that only use the gradient information, the only class of methods that are computationally viable in practice. In this Thesis, we study first-order methods and their convergence to the solutions of nonconvex-nonconcave minimax optimization problems. We also show the properties of the minimax generalization of the Moreau Envelope in the constrained setting which, we believe, can be of independent interest in future research endeavors in this field.
Boundary-induced nucleation control: A theoretical perspective
Creators: name: Buller, Oleg
name: Wang, Hong
name: Wang, Wenchong
name: Chi, Lifeng
name: Heuer, Andreas
Publisher: name: arXiv
Year: 2015
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The pre-patterning of a substrate to create energetically more attractive or repulsive regions allows one to generate a variety of structures in physical vapor deposition experiments. A particular interesting structure is generated if the energetically attractive region is forming a rectangular grid. For specific combinations of the particle flux, the substrate temperature and the lattice size it is possible to generate exactly one cluster per cell, giving rise to nucleation control. Here, we show that the experimental observations of nucleation control can be very well understood from a theoretical perspective. For this purpose we perform, on the one hand, kinetic Monte Carlo simulations and, on the other hand, use analytical scaling arguments to rationalize the observed behavior. For several observables, characterizing nucleation control, a very good agreement is found between experiment and theory. This underlines the generality of the presented mechanism to control the deposition of material by manipulation of the direct environment.
description: 9 pages (two-columned), 11 figures (updated), Phys. Chem. Chem. Phys. (2018)
Bipartite qutrit local realist inequalities and the robustness of their quantum mechanical violation
Creators: name: Das, Debarshi
name: Datta, Shounak
name: Goswami, Suchetana
name: Majumdar, A. S.
name: Home, Dipankar
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Distinct from the type of local realist inequality (known as the Collins-Gisin-Linden-Massar-Popescu or CGLMP inequality) usually used for bipartite qutrit systems, we formulate a new set of local realist inequalities for bipartite qutrits by generalizing Wigner's argument that was originally formulated for the bipartite qubit singlet state. This treatment assumes existence of the overall joint probability distributions in the underlying stochastic hidden variable space for the measurement outcomes pertaining to the relevant trichotomic observables, satisfying the locality condition and yielding the measurable marginal probabilities. Such generalized Wigner inequalities (GWI) do not reduce to Bell-CHSH type inequalities by clubbing any two outcomes, and are violated by quantum mechanics (QM) for both the bipartite qutrit isotropic and singlet states using trichotomic observables defined by six-port beam splitter as well as by the spin-$1$ component observables. The efficacy of GWI is then probed in these cases by comparing the QM violation of GWI with that obtained for the CGLMP inequality. This comparison is done by incorporating white noise in the singlet and isotropic qutrit states. It is found that for the six-port beam splitter observables, QM violation of GWI is more robust than that of the CGLMP inequality for singlet qutrit states, while for isotropic qutrit states, QM violation of the CGLMP inequality is more robust. On the other hand, for the spin-$1$ component observables, QM violation of GWI is more robust for both the type of states considered.
description: Published Version
Απαιτήσεις ή και ανάγκες αποτελεσματικής επικοινωνίας στα πλαίσια των συστημάτων διαχείρισης ποιότητας
Creators: name: Πρεμέτης, Ηλίας
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Αποτελεσματική επικοινωνία

description: Η αποτελεσματική επικοινωνία είναι υψίστης σημασίας στις επιχειρήσεις, διαδραματίζοντας κρίσιμο ρόλο στην επίλυση προβλημάτων και στα συστήματα διαχείρισης ποιότητας. Προωθεί μια κουλτούρα ενεργητικής ακρόασης, ανατροφοδότησης και ανοιχτού διαλόγου, ενισχύοντας τις ικανότητες επίλυσης προβλημάτων και την παραγωγικότητα. Στα συστήματα διαχείρισης ποιότητας, η αποτελεσματική επικοινωνία διασφαλίζει ότι τα πρότυπα, οι διαδικασίες και οι προσδοκίες κοινοποιούνται ξεκάθαρα σε ολόκληρο τον οργανισμό. Συμπερασματικά, η αποτελεσματική επικοινωνία είναι απαραίτητη στις επιχειρήσεις, επιτρέποντας αποτελεσματική επίλυση προβλημάτων και ισχυρά συστήματα διαχείρισης ποιότητας. Προωθεί τη συνεργασία, ενισχύει την παραγωγικότητα, διασφαλίζει τη συνέπεια και διευκολύνει την επίτευξη των επιχειρηματικών στόχων. Δίνοντας προτεραιότητα στην αποτελεσματική επικοινωνία, οι οργανισμοί μπορούν να καλλιεργήσουν μια κουλτούρα διαφάνειας, αφοσίωσης και συνεχούς βελτίωσης, οδηγώντας στην επιτυχία στην επίλυση προβλημάτων και τις προσπάθειες διαχείρισης ποιότητας. Στο εισαγωγικό κεφάλαιο 1 παρουσιάζονται εκτενέστερα αυτές οι ανάγκες, και στη συνέχεια στο κεφάλαιο 2, τεκμηριώνονται μέσα από τη βιβλιογραφική ανασκόπηση. Ακόμα, στο κεφάλαιο 3 αναλύεται το πρότυπο ISO100018:2020, ενώ στο κεφάλαιο 4 φαίνεται η σύνδεσή του με το πρότυπο ISO 9001:2015 στο κομμάτι της επικοινωνίας. Τέλος, παρουσιάζεται ένα παράδειγμα για τον τρόπο επικοινωνίας των γενικών οδηγιών μιας βιομηχανικής εταιρίας, και το πώς μέσω τη τυποποίησης της επικοινωνίας και των πιστοποιημένων εγγράφων καλύπτονται οι επικαιροποιημένες ανάγκες της.
The new European regulation on Health Technology Assessment: what changes for Advanced Therapy Medicinal Products?
Creators: name: Bartos Blanka
name: Juët Joséphine
name: Taboulet Florence
name: Aurélie, Mahalatchimy
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the 2022 European Society of Gene & Cell Therapy Congress in Edinburgh.
description: Also available: https://shs.hal.science/halshs-03901269v1
Adaptive density estimation based on a mixture of Gammas
Creators: name: Bochkina, Natalia
name: Rousseau, Judith
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62G07, 62G20

description: We consider the problem of Bayesian density estimation on the positive semiline for possibly unbounded densities. We propose a hierarchical Bayesian estimator based on the gamma mixture prior which can be viewed as a location mixture. We study convergence rates of Bayesian density estimators based on such mixtures. We construct approximations of the local Hölder densities, and of their extension to unbounded densities, to be continuous mixtures of gamma distributions, leading to approximations of such densities by finite mixtures. These results are then used to derive posterior concentration rates, with priors based on these mixture models. The rates are minimax (up to a log n term) and since the priors are independent of the smoothness the rates are adaptive to the smoothness.
Faking SM Photons by Displaced Dark Photon Decays
Creators: name: Tsai, Yuhsin
name: Wang, Lian-Tao
name: Zhao, Yue
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A light meta-stable dark photon decaying into collimated electron/positron pair can fake a photon, either converted or unconverted, at the LHC. The detailed object identification relies on the specifics of the detector and strategies for the reconstruction. We study the fake rate based on the ATLAS(CMS) detector geometry and show that it can be O(1) with a generic choice of parameters. Especially, the probability of being registered as a photon is angular dependent. Such detector effects can induce bias to measurements on certain properties of new physics. In this paper, we consider the scenario where dark photons in final states are from a heavy resonance decay. Consequently, the detector effects can dramatically affect the results when determine the spin of a resonance. Further, if the decay products from the heavy resonance are one photon and one dark photon, which has a large probability to fake a diphoton event, the resonance is allowed to be a vector. Due to the difference in detector, the cross sections measured in ATLAS and CMS do not necessarily match. Furthermore, if the diphoton signal is given by the dark photons, the SM $Zγ$ and $ZZ$ final states do not necessarily come with the $γγ$ channel, which is a unique signature in our scenario. The issue studied here is relevant also for any future new physics searches with photon(s) in the final state. We discuss possible ways of distinguishing dark photon decay and real photon in the future.
description: 11 pages + reference, 6 figures; add more discussions on the converted/unconverted photon ratio; matches version published in PRD
Phase Structure of 1d Interacting Floquet Systems I: Abelian SPTs
Creators: name: von Keyserlingk, C. W.
name: Sondhi, S. L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Recent work suggests that a sharp definition of `phase of matter' can be given for some quantum systems out of equilibrium---first for many-body localized systems with time independent Hamiltonians and more recently for periodically driven or Floquet localized systems. In this work we propose a classification of the finite abelian symmetry protected phases of interacting Floquet localized systems in one dimension. We find that the different Floquet phases correspond to elements of $\text{Cl}\times\mathcal{A}_G$, where $\text{Cl}$ is the undriven interacting classification, and $\mathcal{A}_G$ is a set of (twisted) 1d representations of $G$. We will address symmetry broken phases in a subsequent paper.
description: 21 pages. Explained connection to the classification schemes in other recent work. Close to published version
Specific guidelines requirements for clinical trials with Advanced Therapy Medicinal Products in the EU
Creators: name: Aurélie, Mahalatchimy
name: Gennet Eloïse
name: Michael, Morrison
name: Andrieu Véronique
name: Véran Julie
name: Sabatier Florence
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the 2022 European Society of Gene & Cell Therapy Congress in Edinburgh.
description: Also available: https://shs.hal.science/halshs-03901386v1
The current revision of the orphan medicines regulation in the EU: what is at stake for gene and cell therapy?
Creators: name: Aurélie, Mahalatchimy
name: Gennet Eloïse
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the 2022 European Society of Gene & Cell Therapy Congress in Edinburgh.
description: Also available: https://shs.hal.science/halshs-03901429v1
An Open-Source Multi-Robot Construction System
Creators: name: Allwright, Michael
name: Zhu, Weixu
name: Dorigo, Marco
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: construction
subject: multi-robot system
subject: open-source hardware
subject: robotics

description: This repository contains the design files, the bill of materials, and assembly videos for SRoCS: A swarm robotics construction system. SRoCS is designed for running experiments in a laboratory setting where the intelligence that coordinates construction may be embedded not only in the robots but also in the building material.
Investigation of Compressive and Tensile Behavior of Stainless Steel/Dissolvable Aluminum Bimetallic Composites by Finite  Element Modelling and Digital Image Correlation
Creators: Li, X.
Ghasri-Khouzani, M.
Bogno, A.-A.
Liu, J.
Henein, H.
Chen, Z.
Qureshi, A.J.
Publisher: name: University of Alberta Library
Year: 2021

This study reports fabrication, mechanical characterization, and finite element modeling of a novel lattice structure based bimetallic composite comprised of 316L stainless steel and a func-tional dissolvable aluminum alloy. A net-shaped 316L stainless steel lattice structure composed of diamond unit cells was fabricated by selective laser melting (SLM). The cavities in the lattice structure were then filled through vacuum-assisted melt infiltration to form the bimetallic composite. The bulk aluminum sample was also cast using the same casting parameters for comparison. The compressive and tensile behavior of 316L stainless steel lattice, bulk dissolva-ble aluminum, and 316L stainless steel/dissolvable aluminum bimetallic composite and the comparison between experimental, finite element analysis (FEA) and digital image correlation (DIC) results, were investigated in this study. There is no notable difference in the tensile be-havior of the lattice and bimetallic composite because of the weak bonding in the interface, so the load cannot be transferred from the 316L stainless steel lattice to the dissolvable aluminum matrix. However, the aluminum matrix is vital in the compressive behavior of the bimetallic composite. The dissolvable aluminum showed higher Young's modulus, yield stress, and ulti-mate stress than the lattice and composite in both tension and compression tests, but much less elongation. Moreover, FEA and DIC have demonstrated to be effective and efficient methods to simulate, analyze, and verify the experimental results through juxtaposing curves on the plots and compare strains of critical points by checking contour plots, respectively.
Production of ATMPs: What are the specificities for quality aspects?
Creators: name: Aurélie, Mahalatchimy
name: Gennet Eloïse
name: Michael, Morrison
name: Andrieu Véronique
name: Véran Julie
name: Sabatier Florence
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the 2022 European Society of Gene & Cell Therapy Congress in Edinburgh.
description: Also available: https://shs.hal.science/halshs-03901462v1
Regularity properties of fiber derivatives associated with higher-order mechanical systems
Creators: name: Colombo, Leonardo
name: Prieto-Martínez, Pedro D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 70H50, 53D05, 53D12

description: The aim of this work is to study fiber derivatives associated to Lagrangian and Hamiltonian functions describing the dynamics of a higher-order autonomous dynamical system. More precisely, given a function in $T^*T^{(k-1)}Q$, we find necessary and sufficient conditions for such a function to describe the dynamics of a kth-order autonomous dynamical system, thus being a kth-order Hamiltonian function. Then, we give a suitable definition of (hyper)regularity for these higher-order Hamiltonian functions in terms of their fiber derivative. In addition, we also study an alternative characterization of the dynamics in Lagrangian submanifolds in terms of the solutions of the higher-order Euler-Lagrange equations.
description: 31 pp. Minor corrections in the revised version
Expect to be distracted: Prediction of salient distractor by action and cue attenuates its interference
Creators: name: Havlíček, Ondřej
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: attention
subject: attentional capture
subject: attentional white bear
subject: cognitive psychology
subject: forward model
subject: motor control
subject: predictive coding
subject: sense of agency
subject: sensory attenuation

description: Behavioral study testing the specific effects of action-effect prediction on visual attention.
An effective magnetic field from optically driven phonons
Creators: name: Nova, T. F.
name: Cartella, A.
name: Cantaluppi, A.
name: Foerst, M.
name: Bossini, D.
name: Mikhaylovskiy, R. V.
name: Kimel, A. V.
name: Merlin, R.
name: Cavalleri, A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Light fields at THz and mid-infrared frequencies allow for the direct excitation of collective modes in condensed matter, which can be driven to large amplitudes. For example, excitation of the crystal lattice, has been shown to stimulate insulator-metal transitions, melt magnetic order, or enhance superconductivity. Here, we generalize these ideas and explore the simultaneous excitation of more than one lattice mode, which are driven with controlled relative phases. This nonlinear mode mixing drives rotations as well as displacements of the crystal-field atoms, mimicking the application of a magnetic field and resulting in the excitation of spin precession in the rare-earth orthoferrite $ErFeO_3$. Coherent control of lattice rotations may become applicable to other interesting problems in materials research, for example as a way to affect the topology of electronic phases.
description: 18 pages, 5 figures
Finite Range Decomposition for Gaussian Measures with Improved Regularity
Creators: name: Buchholz, Simon
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider a family of gradient Gaussian vector fields on the torus $(\mathbb{Z}/L^N\mathbb{Z})^d$. Adams, Kotecký, Müller and independently Bauerschmidt established the existence of a uniform finite range decomposition of the corresponding covariance operators, i.e., the covariance can be written as a sum of covariance operators supported on increasing cubes with diameter $L^k$. We improve this result and show that the decay behaviour of the kernels in Fourier space can be controlled. Then we show the regularity of the integration map that convolves functionals with the partial measures of the finite range decomposition. In particular the new finite range decomposition avoids the loss of regularity which arises in the renormalisation group approach to anisotropic problems in statistical mechanics.
description: 28 pages, more general interactions and smoothness statement, construction now based on the Bauerschmidt decomposition
AI4IA Conference Report 2023
Creators: UNESCO Information For All Programme (IFAP)
Publisher: name: University of Alberta Library
Year: 2023

The UNESCO Information For All Programme (IFAP) Working Group on Information Accessibility (WGIA) hosted its fourth online, one-day conference on 28 September 2023. The event was organized in collaboration with the College of Social Sciences and Humanities at the University of Alberta, Canada; the Alberta Machine Intelligence Institute (Amii); the Centre for New Economic Diplomacy (CNED) at ORF, India; and the Broadcasting Commission of Jamaica, all under the auspices of the UNESCO Cluster Office for the Caribbean and the UNESCO Regional Office for Southern Africa.

AI can be very beneficial to society, but if abused, it can cause harm. It is therefore necessary to understand how AI can be made inclusive, enabling the widest cross-section of society to benefit. This event provided a platform for open discourse involving participants from academia, civil society, the private sector, and government. Participants explored a range of issues including: AI and Participatory Democracy; AI and War; AI and the Environment; The Convergence of AI and Neuro-technology; AI and Law; Implications of Large Language Models; Gendered Perspectives on AI; Culture, Indigenous Societies, and Data Sovereignty; Data Scraping and Exploitation; Digital Rights of Children; the Use of AI to Overcome Disabilities and Deliver Access; AI and Longtermism; AI and Health; the Intersection of AI, Art, and Human Creativity; and the Governance of AI, including Tensions Around the Concepts of Freedom of Expression and Information Accessibility.
Query Reranking As A Service
Creators: name: Asudeh, Abolfazl
name: Zhang, Nan
name: Das, Gautam
Publisher: name: arXiv
Year: 2016
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: The ranked retrieval model has rapidly become the de facto way for search query processing in client-server databases, especially those on the web. Despite of the extensive efforts in the database community on designing better ranking functions/mechanisms, many such databases in practice still fail to address the diverse and sometimes contradicting preferences of users on tuple ranking, perhaps (at least partially) due to the lack of expertise and/or motivation for the database owner to design truly effective ranking functions. This paper takes a different route on addressing the issue by defining a novel {\em query reranking problem}, i.e., we aim to design a third-party service that uses nothing but the public search interface of a client-server database to enable the on-the-fly processing of queries with any user-specified ranking functions (with or without selection conditions), no matter if the ranking function is supported by the database or not. We analyze the worst-case complexity of the problem and introduce a number of ideas, e.g., on-the-fly indexing, domination detection and virtual tuple pruning, to reduce the average-case cost of the query reranking algorithm. We also present extensive experimental results on real-world datasets, in both offline and live online systems, that demonstrate the effectiveness of our proposed techniques.
description: Proceedings of the VLDB Endowment (PVLDB), Vol. 9, No. 11, 2016
Curves in $\mathbb{R}^4$ and two-rich points
Creators: name: Guth, Larry
name: Zahl, Joshua
Publisher: name: arXiv
Year: 2015
Subjects: subject: Combinatorics (math.CO)
subject: Computational Geometry (cs.CG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: We obtain a new bound on the number of two-rich points spanned by an arrangement of low degree algebraic curves in $\mathbb{R}^4$. Specifically, we show that an arrangement of $n$ algebraic curves determines at most $C_εn^{4/3+3ε}$ two-rich points, provided at most $n^{2/3+2ε}$ curves lie in any low degree hypersurface and at most $n^{1/3+ε}$ curves lie in any low degree surface. This result follows from a structure theorem about arrangements of curves that determine many two-rich points.
description: 20 pages, 0 figures. v2: fixed an error in Section 5.2
Towards Understanding Sparse Filtering: A Theoretical Perspective
Creators: name: Zennaro, Fabio Massimo
name: Chen, Ke
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In this paper we present a theoretical analysis to understand sparse filtering, a recent and effective algorithm for unsupervised learning. The aim of this research is not to show whether or how well sparse filtering works, but to understand why and when sparse filtering does work. We provide a thorough theoretical analysis of sparse filtering and its properties, and further offer an experimental validation of the main outcomes of our theoretical analysis. We show that sparse filtering works by explicitly maximizing the entropy of the learned representation through the maximization of the proxy of sparsity, and by implicitly preserving mutual information between original and learned representations through the constraint of preserving a structure of the data, specifically the structure defined by relations of neighborhoodness under the cosine distance. Furthermore, we empirically validate our theoretical results with artificial and real data sets, and we apply our theoretical understanding to explain the success of sparse filtering on real-world problems. Our work provides a strong theoretical basis for understanding sparse filtering: it highlights assumptions and conditions for success behind this feature distribution learning algorithm, and provides insights for developing new feature distribution learning algorithms.
description: 54 pages, 9 figures
Disentangling surface and bulk transport in topological-insulator $p$-$n$ junctions
Creators: name: Backes, D.
name: Huang, D.
name: Mansell, R.
name: Lanius, M.
name: Kampmeier, J.
name: Ritchie, D. A.
name: Mussler, G.
name: Gumbs, G.
name: Grützmacher, D.
name: Narayan, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: By combining $n$-type $\mathrm{Bi_2Te_3}$ and $p$-type $\mathrm{Sb_2Te_3}$ topological insulators, vertically stacked $p$-$n$ junctions can be formed, allowing to position the Fermi level into the bulk band gap and also tune between $n$- and $p$-type surface carriers. Here we use low-temperature magnetotransport measurements to probe the surface and bulk transport modes in a range of vertical $\mathrm{Bi_2Te_3/Sb_2Te_3}$ heterostructures with varying relative thicknesses of the top and bottom layers. With increasing thickness of the $\mathrm{Sb_2Te_3}$ layer we observe a change from $n$- to $p$-type behavior via a specific thickness where the Hall signal is immeasurable. Assuming that the the bulk and surface states contribute in parallel, we can calculate and reproduce the dependence of the Hall and longitudinal components of resistivity on the film thickness. This highlights the role played by the bulk conduction channels which, importantly, cannot be probed using surface sensitive spectroscopic techniques. Our calculations are then buttressed by a semi-classical Boltzmann transport theory which rigorously shows the vanishing of the Hall signal. Our results provide crucial experimental and theoretical insights into the relative roles of the surface and bulk in the vertical topological $p$-$n$ junctions.
description: 11 pages, 5 figures
Hyperkähler fourfolds and Kummer surfaces
Creators: name: Iliev, Atanas
name: Kapustka, Grzegorz
name: Kapustka, Michał
name: Ranestad, Kristian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We show that a Hilbert scheme of conics on a Fano fourfold double cover of $\mathbb{P}^2\times\mathbb{P}^2$ ramified along a divisor of bidegree $(2,2)$ admits a $\mathbb{P}^1$-fibration with base being a hyper-Kähler fourfold. We investigate the geometry of such fourfolds relating them with degenerated EPW cubes, with elements in the Brauer groups of $K3$ surfaces of degree $2$, and with Verra threefolds studied in [Ver04]. These hyper-Kähler fourfolds admit natural involutions and complete the classification of geometric realizations of anti-symplectic involutions on hyper-Kähler $4$-folds of type $K3^{[2]}$. As a consequence we present also three constructions of quartic Kummer surfaces in $\mathbb{P}^3$: as Lagrangian and symmetric degeneracy loci and as the base of a fibration of conics in certain threefold quadric bundles over $\mathbb{P}^1$.
description: to appear in Proceedings of the London Mathematical Society
Discontinuous Galerkin Deterministic Solvers for a Boltzmann-Poisson Model of Hot Electron Transport by Averaged Empirical Pseudopotential Band Structures
Creators: name: Morales-Escalante, Jose
name: Gamba, Irene M.
name: Cheng, Yingda
name: Majorana, Armando
name: Shu, Chi-Wang
name: Chelikowsky, James
Publisher: name: arXiv
Year: 2015
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The purpose of this work is to incorporate numerically, in a discontinuous Galerkin (DG) solver of a Boltzmann-Poisson model for hot electron transport, an electronic conduction band whose values are obtained by the spherical averaging of the full band structure given by a local empirical pseudopotential method (EPM) around a local minimum of the conduction band for silicon, as a midpoint between a radial band model and an anisotropic full band, in order to provide a more accurate physical description of the electron group velocity and conduction energy band structure in a semiconductor. This gives a better quantitative description of the transport and collision phenomena that fundamentally define the behaviour of the Boltzmann - Poisson model for electron transport used in this work. The numerical values of the derivatives of this conduction energy band, needed for the description of the electron group velocity, are obtained by means of a cubic spline interpolation. The EPM-Boltzmann-Poisson transport with this spherically averaged EPM calculated energy surface is numerically simulated and compared to the output of traditional analytic band models such as the parabolic and Kane bands, numerically implemented too, for the case of 1D $n^+-n-n^+$ silicon diodes with 400nm and 50nm channels. Quantitative differences are observed in the kinetic moments related to the conduction energy band used, such as mean velocity, average energy, and electric current (momentum).
description: submission to CMAME (Computer Methods in Applied Mechanics and Engineering) Journal as a reply to the reviewers on February 2017
AGI and ASI
Creators: name: Zukowski, Novak I. K.
name: Kourouklides, Ioannis
Publisher: name: Open Science Framework
Year: 2023
Subjects: subject: ASI
subject: Artificial General Intelligence
subject: deep learning
subject: robotics
subject: Artificial Superintelligence
subject: emergence
subject: Complex Systems
subject: AGI
subject: representation learning
subject: machine learning
subject: Signal Processing
subject: reinforcement learning
subject: continual learning
subject: Natural Language Processing
subject: decentralization
subject: causal learning
subject: bayesian learning
subject: artificial intelligence
subject: Dynamical Systems
subject: consciousness
subject: GUT-AI
subject: Control Theory

description: AGI and ASI
Untere Schranken für Steinerbaumalgorithmen und die Konstruktion von Bicliquen in dichten Graphen
Creators: name: Kirchner, Stefan
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II
Year: 2008
Subjects: subject: Steinerbaum
subject: Approximationsalgorithmen
subject: untere Schranken
subject: Bicliquen
subject: Steiner tree
subject: approximation algorithms
subject: lower bounds
subject: bicliques
subject: 004 Informatik
subject: 28 Informatik, Datenverarbeitung

description: Die vorliegende Arbeit besteht aus zwei Teilen. Der erste Teil der Arbeit befasst sich mit unteren Schranken für approximative Steinerbaumalgorithmen. Ein Steinerbaum ist ein kürzester Teilgraph, der eine gegebene Teilmenge der Knoten eines Graphen spannt. Das Berechnen eines Steinerbaumes ist ein klassisches NP-schweres Problem, und es existieren mehrere Approximationsalgorithmen, wobei bei den meisten Algorithmen die Approximationsgüte nur durch untere und obere Schranken eingegrenzt werden kann. Für einige dieser Algorithmen werden in dieser Arbeit Instanzen vorgestellt, welche die unteren Schranken verbessern. Für den Relativen Greedy Algorithmus wird außerdem ein Verfahren vorgestellt, mit dem die Güte des Algorithmus eingeschränkt auf die Graphenklasse mit k Terminalen auf einen beliebigen Faktor genau bestimmt werden kann. Der zweite Teil der Arbeit widmet sich vollständig bipartiten Subgraphen mit gleicher Partitionsgrößse, sogenannten balancierten Bicliquen. Seit langem ist bekannt, dass in dichten bipartiten Graphen balancierte Bicliquen mit Omega(log(n)) Knoten existieren, aber es ist unbekannt, ob und wie diese in polynomieller Zeit konstruiert werden können. Der zweite Teil liefert dazu einen Beitrag, indem ein polynomieller Algorithmus vorgestellt wird, der in hinreichend großen dichten bipartiten Graphen eine balancierte Biclique mit Omega(sqrt(log(n))) Knoten konstruiert.
description: This thesis consists of two parts. The first part is concerned with lower bounds for approximating Steiner trees. The Steiner tree problem is to find a shortest subgraph that spans a given set of vertices in a graph and is a classical NP-hard problem. Several approximation algorithms exist, but for most algorithms only lower and upper bounds for the approximation ratio are known. For some of these algorithms we present instances which improve the lower bounds. When the problem is restricted to the class of graphs with k terminals, we also present a method which can be used to determine the approximation ratio of the Relative Greedy Algorithm with arbitrary precision. The second part is about balanced bicliques, i.e. complete bipartite subgraphs with equal partition sizes. It has been known for a long time that every dense bipartite graph contains a balanced biclique of size Omega(log(n)), but whether and how such a biclique can be constructed in polynomial time is still unknown. Our contribution to this problem is a polynomial time algorithm which constructs a balanced biclique of size Omega(sqrt(log(n))) in sufficiently large and dense bipartite graphs.
Nonchaotic evolution of triangular configuration due to gravitational radiation reaction in the three-body problem
Creators: name: Yamada, Kei
name: Asada, Hideki
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Continuing work initiated in an earlier publication [H. Asada, Phys. Rev. D {\bf 80}, 064021 (2009)], the gravitational radiation reaction to Lagrange's equilateral triangular solution of the three-body problem is investigated in an analytic method. The previous work is based on the energy balance argument, which is sufficient for a two-body system because the number of degrees of freedom (the semimajor axis and the eccentricity in quasi-Keplerian cases, for instance) equals that of the constants of motion such as the total energy and the orbital angular momentum. In a system with three (or more) bodies, however, the number of degrees of freedom is more than that of the constants of motion. Therefore, the present paper discusses the evolution of the triangular system by directly treating the gravitational radiation reaction force to each body. The perturbed equations of motion are solved by using the Laplace transform technique. It is found that the triangular configuration is adiabatically shrinking and is kept in equilibrium by increasing the orbital frequency due to the radiation reaction if the mass ratios satisfy the Newtonian stability condition. Long-term stability involving the first post-Newtonian corrections is also discussed.
description: 19 pages, 2 figures; accepted by PRD
A Complex-Network Perspective on Alexander's Wholeness
Creators: name: Jiang, Bin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: The wholeness, conceived and developed by Christopher Alexander, is what exists to some degree or other in space and matter, and can be described by precise mathematical language. However, it remains somehow mysterious and elusive, and therefore hard to grasp. This paper develops a complex network perspective on the wholeness to better understand the nature of order or beauty for sustainable design. I bring together a set of complexity-science subjects such as complex networks, fractal geometry, and in particular underlying scaling hierarchy derived by head/tail breaks - a classification scheme and a visualization tool for data with a heavy-tailed distribution, in order to make Alexander's profound thoughts more accessible to design practitioners and complexity-science researchers. Through several case studies (some of which Alexander studied), I demonstrate that the complex-network perspective helps reduce the mystery of wholeness and brings new insights to Alexander's thoughts on the concept of wholeness or objective beauty that exists in fine and deep structure. The complex-network perspective enables us to see things in their wholeness, and to better understand how the kind of structural beauty emerges from local actions guided by the 15 fundamental properties, and by differentiation and adaptation processes. The wholeness goes beyond current complex network theory towards design or creation of living structures. Keywords: Theory of centers, living geometry, Christopher Alexander, head/tail breaks, and beauty
description: 12 pages, 6 figures, 2 tables, minor text revision