cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spin-orbit torques from topological insulator surface states: Effect of extrinsic spin-orbit scattering on an out-of-plane magnetization
Creators: name: Farokhnezhad, Mohsen
name: Asgari, Reza
name: Culcer, Dimitrie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The origins of the spin-orbit torque (SOT) at ferromagnet/topological insulator (FM/TI) interfaces are incompletely understood. Theory has overwhelmingly focussed on the Edelstein effect due to the surface states in the presence of a scalar scattering potential. We investigate here the contribution to the SOT due to extrinsic spin-orbit scattering of the surface states, focusing on the case of an out-of-plane magnetization. We show that spin-orbit scattering brings about a sizable renormalization of the field-like SOT, which exceeds 20$\%$ at larger strengths of the extrinsic spin-orbit parameter. The resulting SOT exhibits a maximum as a function of the Fermi energy, magnetization, and extrinsic spin-orbit strength. The field-like SOT decreases with increasing disorder strength while the damping-like SOT is independent of the impurity density. With experimental observation in mind we also determine the role of extrinsic spin-orbit scattering on the anomalous Hall effect. Our results suggest extrinsic spin-orbit scattering is a significant contributor to the surface SOT stemming from the Edelstein effect when the magnetization is out of the plane.
description: 18 pages, 5 figures
Is glass a state of matter?
Creators: name: Guiselin, Benjamin
name: Tarjus, Gilles
name: Berthier, Ludovic
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Glass is everywhere. We use and are surrounded by glass objects which make tangible the reality of glass as a distinct state of matter. Yet, glass as we know it is usually obtained by cooling a liquid sufficiently rapidly below its melting point to avoid crystallisation. The viscosity of this supercooled liquid increases by many orders of magnitude upon cooling, until the liquid becomes essentially arrested on experimental timescales below the ``glass transition'' temperature. From a structural viewpoint, the obtained glass still very much resembles the disordered liquid, but from a mechanical viewpoint, it is as rigid as an ordered crystal. Does glass qualify as a separate state of matter? We provide a pedagogical perspective on this question using basic statistical mechanical concepts. We recall the definitions of states of matter and of phase transitions between them. We review recent theoretical results suggesting why and how an ``ideal glass'' can indeed be defined as a separate equilibrium state of matter. We discuss recent success of computer simulations trying to analyse this glass state. We close with some experimental perspectives.
description: 10 pages, 4 figures. Pedagogical article based on talk given at 16th International Conference on the Physics of Non-Crystalline Solids, Canterbury (2022)
Artifact Identification in X-ray Diffraction Data using Machine Learning Methods
Creators: name: Yanxon, Howard
name: Weng, James
name: Parraga, Hannah
name: Xu, Wenqian
name: Ruett, Uta
name: Schwarz, Nicholas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The in situ synchrotron high-energy X-ray powder diffraction (XRD) technique is highly utilized by researchers to analyze the crystallographic structures of materials in functional devices (e.g., battery materials) or in complex sample environments (e.g., diamond anvil cells or syntheses reactors). An atomic structure of a material can be identified by its diffraction pattern, along with detailed analysis such as Rietveld refinement which indicates how the measured structure deviates from the ideal structure (e.g., internal stresses or defects). For in situ experiments, a series of XRD images is usually collected on the same sample at different conditions (e.g., adiabatic conditions), yielding different states of matter, or simply collected continuously as a function of time to track the change of a sample over a chemical or physical process. In situ experiments are usually performed with area detectors, collecting 2D images composed of diffraction rings for ideal powders. Depending on the material's form, one may observe different characteristics other than the typical Debye Scherrer rings for a realistic sample and its environments, such as textures or preferred orientations and single crystal diffraction spots in the 2D XRD image. In this work, we present an investigation of machine learning methods for fast and reliable identification and separation of the single crystal diffraction spots in XRD images. The exclusion of artifacts during an XRD image integration process allows a precise analysis of the powder diffraction rings of interest. We observe that the gradient boosting method can consistently produce high accuracy results when it is trained with small subsets of highly diverse datasets. The method dramatically decreases the amount of time spent on identifying and separating single crystal spots in comparison to the conventional method.
Supersolids: what and where are they ?
Creators: name: Boninsegni, Massimo
name: Prokof'ev, Nikolay
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The ongoing experimental and theoretical effort aimed at understanding non-classical rotational inertia in solid helium, has sparked renewed interest in the supersolid phase of matter, its microscopic origin and character, and its experimental detection. The purpose of this colloquium is a) to provide a general theoretical framework for the phenomenon of supersolidity and b) to review some of the experimental evidence for solid Helium-four, and discuss its possible interpretation in terms of physical effects underlain by extended defects (such as dislocations). We provide quantitative support to our theoretical scenarios by means of first principle numerical simulations. We also discuss alternate avenues for the observation of the supersolid phase, not involving helium but rather assemblies of ultracold atoms.
description: 20 pages, 7 figures, accepted for publication as a Colloquium in the Review of Modern Physics
Education, gender and erosion of tradition: perceptions and experience of second-generation Chinese
Creators: name: Chow, Jo-Anne May
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: JV6225 .C46 1998
subject: Additional Copy: 370 EDC 1998 CHO in the Doucette Education Library
subject: Canada - Emigration and immigration - Social aspects
subject: Children of immigrants - Education - Social Aspects - Alberta - Calgary

description: Bibliography: p. 107-111
Implications of multiwavelength spectrum on cosmic-ray acceleration in blazar TXS 0506+056
Creators: name: Das, Saikat
name: Gupta, Nayantara
name: Razzaque, Soebur
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: MAGIC collaboration has recently analyzed data from a long-term multiwavelength campaign of the $γ$-ray blazar TXS 0506+056. In December 2018, it was flaring in the very-high-energy (VHE; $E>100$ GeV) $γ$-ray band, but no simultaneous neutrino event was detected. We model the observed spectral energy distribution (SED), using a one-zone leptohadronic emission. We estimate the neutrino flux through the restriction from observed X-ray flux on the secondary radiation due to hadronic cascade, initiated by protons with energy $E_p \lesssim 0.1$ EeV. We assume ultrahigh-energy cosmic rays (UHECRs; $E\gtrsim0.1$ EeV), with the same slope and normalization as the low-energy spectrum, are accelerated in the jet but escape efficiently. We propagate the UHE protons in a random, turbulent extragalactic magnetic field (EGMF). The leptonic emission from the jet dominates the GeV range, whereas the cascade emission from CR interactions in the jet contributes substantially to the X-ray and VHE range. The line-of-sight cosmogenic $γ$ rays from UHECRs produce a hardening in the VHE spectrum. Our model prediction for neutrinos from the jet is consistent with the 7.5-year flux limit by IceCube and shows no variability during the MAGIC campaign. Therefore, we infer that the correlation between GeV-TeV $γ$-rays and neutrino flare is minimal. The luminosity in CRs limits the cosmogenic $γ$-ray flux, which, in turn, bounds the RMS value of the EGMF to $\gtrsim 10^{-5}$ nG. The cosmogenic neutrino flux is lower than the IceCube-Gen2 detection potential for 10 yrs of observation. VHE $γ$-ray variability should arise from increased activity inside the jet; thus, detecting steady flux at multi-TeV energies may indicate UHECR acceleration. Upcoming $γ$-ray imaging telescopes such as the CTA will be able to constrain the cosmogenic $γ$-ray component in the SED of TXS 0506+056.
description: 7 pages, 3 figures, Accepted for publication in A&A
A practical guide to verifiable, evidence-based conservation: sharing and teaching.
Creators: name: Funk, Stephan M
Publisher: name: Zenodo
Year: 2023
Subjects: conservation plan
conservation management
conservation standards
evidence-based conservation
sharing
teaching
data repositories
grey literature

description: Advancements in data analysis, management and sharing have transformed conservation practices. The establishment of global data repositories, repositories for non-peer-reviewed reports, the now common use of the DOI system for peer-reviewed, grey literature and data, and open-access policies by funding agencies have facilitated the widespread availability and transparency of conservation-related data. Specialised databases and journals dedicated to conservation evidence have also emerged, bolstering evidence-based decision-making. Despite progress, challenges remain in managing data deluge, protecting intellectual property rights, and ensuring the responsible sharing of sensitive information. Addressing these issues is essential for maintaining the integrity and utility of conservation data, which is crucial for formulating effective conservation strategies and achieving tangible environmental outcomes. Clear, accessible communication is essential for engaging stakeholders in conservation efforts and integrating their feedback into environmental management.
Evolution of microstructural and mechanical properties of nanocrystalline Co2FeAl Heusler alloy prepared by mechanical alloying
Creators: name: Hakimi, M.
name: Kameli, P.
name: Salamati, H.
name: Mazaheri, Y.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Mechanical alloying (MA) has been used to fabricate the Co2FeAl Heusler alloy with a nanocrystalline structure. The formation mechanism of the alloy has been investigated. Rietveld analysis showed that all samples that were milled for more than 15 hours had an L21 structure with a space group of Fm3m. The crystallite size and internal strain of the samples were calculated using the Williamson-Hall equation. With mechanical alloying of up to 20 hours the crystallite size of Co2FeAl increased, after which the crystallite size started to decrease. In contrast, internal strain first decreased during the process and then increased with the increase of milling time. The powder obtained after 20 hours of MA was split into three parts and separately annealed at 300, 500 and 700 oC for 5 hours. A considerable increase was observed in the hardness value of powder particles with the increase of annealing temperature up to 500 oC. However, the hardness value of the sample annealed at 700 oC decreased. It seems that this feature is related to parameters such as increase of crystallite size, enhancement of lattice ordering, change in density of defects and impurities and nonstoichiometric effects.
Learning Concept Hierarchies from Text Corpora using Formal Concept Analysis
Creators: name: Cimiano, P.
name: Hotho, A.
name: Staab, S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We present a novel approach to the automatic acquisition of taxonomies or concept hierarchies from a text corpus. The approach is based on Formal Concept Analysis (FCA), a method mainly used for the analysis of data, i.e. for investigating and processing explicitly given information. We follow Harris distributional hypothesis and model the context of a certain term as a vector representing syntactic dependencies which are automatically acquired from the text corpus with a linguistic parser. On the basis of this context information, FCA produces a lattice that we convert into a special kind of partial order constituting a concept hierarchy. The approach is evaluated by comparing the resulting concept hierarchies with hand-crafted taxonomies for two domains: tourism and finance. We also directly compare our approach with hierarchical agglomerative clustering as well as with Bi-Section-KMeans as an instance of a divisive clustering algorithm. Furthermore, we investigate the impact of using different measures weighting the contribution of each attribute as well as of applying a particular smoothing technique to cope with data sparseness.
On spectrally flowed local vertex operators in AdS$_3$
Creators: name: Iguri, Sergio
name: Kovensky, Nicolas
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We provide a novel local definition for spectrally flowed vertex operators in the SL(2,$\mathbb{R}$)-WZW model, generalising the proposal of Maldacena and Ooguri in [arXiv:hep-th/0111180] for the singly-flowed case to all $ω> 1$. This allows us to establish the precise connection between the computation of correlators using the so-called spectral flow operator, and the methods introduced recently by Dei and Eberhardt in [arXiv:2105.12130] based on local Ward identities. We show that the auxiliary variable $y$ used in the latter paper arises naturally from a point-splitting procedure in the space-time coordinate. The recursion relations satisfied by spectrally flowed correlators, which take the form of partial differential equations in $y$-space, then correspond to null-state conditions for generalised spectral flowed operators. We highlight the role of the SL(2,$\mathbb{R}$) series identifications in this context, and prove the validity of the conjecture put forward in [arXiv:2105.12130] for $y$-space structure constants of three-point functions with arbitrary spectral flow charges.
description: 25 pages
The trench and gate groundwater remediation system
Creators: name: Bowles, Marc W.
Publisher: name: University of Calgary
Year: 1997
Subjects: subject: TD426. B69 1997A
subject: Additional copy: TD426 .B69 1997 in the Gallagher Library of Geology and Geophysics
subject: Groundwater - Purification
subject: Bioremediation

description: Bibliography: p. 97-103
Evidence for powerful winds and the associated reverse shock as the origin of the Fermi bubbles
Creators: name: Fujita, Yutaka
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Fermi bubbles are large gamma-ray-emitting structures. They are symmetric about the Galactic Centre (GC), and their creation is therefore attributed to intensive energy injection at the GC. In this study, we focus on the non-equilibrium X-ray gas structures associated with the bubbles. We show that a combination of the density, temperature, and shock age profiles of the X-ray gas can be used to distinguish the energy injection mechanisms. By comparing the results of numerical simulations with observations, we indicate that the bubbles were created by a fast wind from the GC because it generates a strong reverse shock and reproduces the observed temperature peak there. On the other hand, instantaneous energy injection at the GC cannot reproduce the temperature profile. The wind had a speed of ~1000 km/s, and blew for ~10^7 yr. Because the mass flux of the wind is large, the entrainment of interstellar gas by wide-angle outflows from the black hole is required. Thus, the wind may be the same as active galactic nuclei outflows often observed in other galaxies and thought to regulate the growth of galaxies and their central black holes.
Anti-inflammatory effects of the macrolide antibiotic tilmicosin
Creators: name: Chin, Alex C.
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: RC735 .A57 C45 1998
subject: Respiratory organs--Pathophysiology.
subject: Lungs--Diseases.
subject: Antibiotics - Physiological effect

description: Bibliography: p. 67-93
The story of Lot and the Qur'an's perception of the morality of same-sex sexuality
Creators: name: Jamal Ebrahim, Amreen Mohamed
Publisher: name: University of Calgary
Year: 1997
Subjects: subject: BJ1292 .H5 M64 1997
subject: Homosexuality--Religious aspects--Islam.
subject: Islam--Sex--Religious aspects.

description: Bibliography: p. 106-112
Deterministic generation of N00N states using quantum dots in a cavity
Creators: name: Leuenberger, Michael N.
name: Erementchouk, Mikhail
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Compared to classical light sources, quantum sources based on N00N states consisting of $N$ photons achieve an $N$-times higher phase sensitivity, giving rise to super-resolution. N00N-state creation schemes based on linear optics and projective measurements only have a success probability $p$ that decreases exponentially with $N$, e.g. $p=4.4\times 10^{-14}$ for N=20. Feed-forward improves the scaling but $N$ fluctuates nondeterministically in each attempt. Schemes based on parametric down-conversion suffer from low production efficiency and low fidelity. A recent scheme based on atoms in a cavity combines deterministic time evolution, local unitary operations, and projective measurements. Here we propose a novel scheme based on the off-resonant interaction of $N$ photons with four semiconductor quantum dots (QDs) in a cavity to create N00N states deterministically with $p=1$ and fidelity above 90% for $N\lesssim 60$, without the need of any projective measurement or local unitary operation. Using our measure we obtain maximum $N$-photon entanglement $E_N=1$ for arbitrary $N$. Our method paves the way to the miniaturization of N00N-state sources to the nanoscale regime, with the possibility to integrate them on a computer chip based on semiconductor materials.
description: 6 pages, 6 figures, RevTex
On the concentration properties of Interacting particle processes
Creators: name: Del Moral, Pierre
name: Hu, Peng
name: Wu, Liming
Publisher: name: arXiv
Year: 2011
Subjects: subject: Numerical Analysis (math.NA)
subject: Probability (math.PR)
subject: FOS: Mathematics

description: These lecture notes present some new concentration inequalities for Feynman-Kac particle processes. We analyze different types of stochastic particle models, including particle profile occupation measures, genealogical tree based evolution models, particle free energies, as well as backward Markov chain particle models. We illustrate these results with a series of topics related to computational physics and biology, stochastic optimization, signal processing and bayesian statistics, and many other probabilistic machine learning algorithms. Special emphasis is given to the stochastic modeling and the quantitative performance analysis of a series of advanced Monte Carlo methods, including particle filters, genetic type island models, Markov bridge models, interacting particle Markov chain Monte Carlo methodologies.
UKIDSS detections of cool brown dwarfs - proper motions of 14 known $>$T5 dwarfs and discovery of three new T5.5-T6 dwarfs
Creators: name: Scholz, Ralf-Dieter
name: Bihain, Gabriel
name: Schnurr, Olivier
name: Storm, Jesper
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: AIMS: We contribute to improving the census of cool brown dwarfs (late-T and Y dwarfs) in the immediate solar neighbourhood. METHODS: By combining near-infrared (NIR) data of UKIDSS with mid-infrared WISE and other available NIR (2MASS) and red optical (SDSS $z$-band) multi-epoch data we detect high proper motion (HPM) objects with colours typical of late spectral types ($>$T5). We use NIR low-resolution spectroscopy for the classification of new candidates. RESULTS: We determined new proper motions for 14 known T5.5-Y0 dwarfs, many of them being significantly ($>$2-10 times) more accurate than previous ones. We detected three new candidates, ULAS J0954+0623, ULAS J1152+0359, and ULAS J1204-0150, by their HPMs and colours. Using previously published and new UKIDSS positions of the known nearby T8 dwarf WISE J0254+0223 we improved its trigonometric parallax to 165$\pm$20 mas. For the three new objects we obtained NIR spectroscopic follow-up with LBT/LUCIFER classifying them as T5.5 and T6 dwarfs. With their estimated spectroscopic distances of about 25-30 pc, their proper motions of about 430-650 mas/yr lead to tangential velocities of about 50-80 km/s typical of the Galactic thin disk population.
description: 5 pages, 2 figures, plus 3 pages with 5 tables (online material), accepted for publication in Astronomy and Astrophysics
title: Dominant Cognitive Strategy in Aphantasia
Creators: name: Pope, Sarah N.
Publisher: name: Utah State University
Year: 2023

description: The purpose of this research was to explore the impact on thinking when an individual is not able to "see with a mind's eye." This is known as aphantasia and is the reduction or absence of visual imagery, which can have large impacts on problem solving and remembering one's own past. The current study examines these impacts by exploring the different ways in which thinking may occur, verbal-analytical, visual imagery, spatial imagery, and how a one's dominant thinking strategy affects performance on a paired work task, a mental rotation task, and an object memory task. Comparing those with typical imagery abilities and those with aphantasia revealed large differences in visual and verbal thinking between those with and without typical imagery abilities, but no differences within the spatial imagery thinking strategy appeared between the two groups. In order to determine if thinking strategy predicts performance on an associated task (verbal-analytical and the paired work task, object imagery and the object memory task, and spatial imagery and the mental rotation task) regression models were used. The analyses revealed only a marginal predicting value for the spatial imagery subscale and the mental rotation task, and no predicting value for the object imagery and verbal-analytical subscales. Results corroborate past research indicating that spatial imagery skills remain intact for those with aphantasia and add to the current literature that aphantasiacs prefer to use verbal thinking strategies over visual ones. However, ceiling effects on the object memory task limited interpretation of the statistical results. Furthermore, the questionnaire used to assess types of thinking has questionable validity. Future research will focus clarifying the different types of thinking and exploring the developmental trajectory of those with aphantasia and the impact on education.
Observational Signatures of Massive Black Hole Progenitor Pathways: Could Leo I a Smoking Gun?
Creators: name: Regan, John A.
name: Pacucci, Fabio
name: Bustamante-Rosell, M. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Observational evidence is mounting regarding the population demographics of Massive Black Holes (MBHs), from the most massive cluster galaxies down to the dwarf galaxy regime. However, the progenitor pathways from which these central MBHs formed remain unclear. Here we report a potentially powerful observational signature of MBH formation in dwarf galaxies. We argue that a continuum in the mass spectrum of MBHs in (fossil) dwarf galaxies would be a unique signature of a heavy seed formation pathway. The continuum in this case would consist of the usual population of stellar mass black holes, formed through stellar evolution, plus a smaller population of heavy seed MBHs which have not yet sunk to the centre of the galaxy. Under the robust assumption of initial fragmentation of the parent gas cloud resulting in a burst of heavy seed production, a significant fraction of these seeds will survive to the present day as off-nuclear MBHs with masses less than that of the central object. Motivated by the recent discovery of a MBH in the relatively low central density Leo I galaxy, we show that such a continuum in MBH seed masses should persist from the lightest black hole masses up to the mass of the central MBH in contrast to the light seeding scenario where no such continuum should exist. The detection of off-centered MBHs and a central MBH would represent strong evidence of a heavy seeding pathway.
description: MNRAS accepted. 7 pages, 2 figures
Shrinking the Quadratic Estimator
Creators: name: Anderes, Ethan
name: Paul, Debashis
Publisher: name: arXiv
Year: 2011
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Applications (stat.AP)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We study a regression characterization for the quadratic estimator of weak lensing, developed by Hu and Okamoto (2001,2002), for cosmic microwave background observations. This characterization motivates a modification of the quadratic estimator by an adaptive Wiener filter which uses the robust Bayesian techniques described in Strawderman (1971) and Berger (1980). This technique requires the user to propose a fiducial model for the spectral density of the unknown lensing potential but the resulting estimator is developed to be robust to misspecification of this model. The role of the fiducial spectral density is to give the estimator superior statistical performance in a "neighborhood of the fiducial model" while controlling the statistical errors when the fiducial spectral density is drastically wrong. Our estimate also highlights some advantages provided by a Bayesian analysis of the quadratic estimator.
Dynamics and Dissipation induced by Single-Electron Tunneling in Carbon Nanotube Nanoelectromechanical Systems
Creators: name: Ganzhorn, Marc
name: Wernsdorfer, Wolfgang
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate the effect of single-electron tunneling (SET) through a carbon nanotube quantum dot on its nanomechanical motion. We find that the frequency response and the dissipation of the nanoelectromechanical system (NEMS) to SET strongly depends on the electronic environment of the quantum dot, in particular on the total dot capacitance and the tunnel coupling to the metal contacts. Our findings suggest that one could achieve quality factors of 10$^{6}$ or higher by choosing appropriate gate dielectrics and/or by improving the tunnel coupling to the leads.
W.B. Yeats and the visual arts
Creators: name: Bryce, Leila Heather
Publisher: name: University of Calgary
Year: 1997
Subjects: subject: PR5908. A75 B79 1998
subject: Yeats, W. B. (William Butler), 1865-1939--Knowledge--Art.
subject: Art in literature

description: Bibliography: p. 109-115
Changes in the hermeneutics of understanding: comparing Friedrich Schleiermacher's "Understanding of the author" with Paul Ricoeur's "Understanding the world of the text"
Creators: name: Calvert, Mechele Marina
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: B2799. C78 C35 1998
subject: Comprehension (Theory of Knowledge)
subject: Knowledge, Theory of
subject: Reading comprehension - Philosophy

description: Bibliography: p. 91-95
Efficiency versus Convergence of Boolean Kernels for On-Line Learning Algorithms
Creators: name: Khardon, R.
name: Roth, D.
name: Servedio, R. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The paper studies machine learning problems where each example is described using a set of Boolean features and where hypotheses are represented by linear threshold elements. One method of increasing the expressiveness of learned hypotheses in this context is to expand the feature set to include conjunctions of basic features. This can be done explicitly or where possible by using a kernel function. Focusing on the well known Perceptron and Winnow algorithms, the paper demonstrates a tradeoff between the computational efficiency with which the algorithm can be run over the expanded feature space and the generalization ability of the corresponding learning algorithm. We first describe several kernel functions which capture either limited forms of conjunctions or all conjunctions. We show that these kernels can be used to efficiently run the Perceptron algorithm over a feature space of exponentially many conjunctions; however we also show that using such kernels, the Perceptron algorithm can provably make an exponential number of mistakes even when learning simple functions. We then consider the question of whether kernel functions can analogously be used to run the multiplicative-update Winnow algorithm over an expanded feature space of exponentially many conjunctions. Known upper bounds imply that the Winnow algorithm can learn Disjunctive Normal Form (DNF) formulae with a polynomial mistake bound in this setting. However, we prove that it is computationally hard to simulate Winnows behavior for learning DNF over such a feature set. This implies that the kernel functions which correspond to running Winnow for this problem are not efficiently computable, and that there is no general construction that can run Winnow with kernels.
Decoherence and its Role in the Modern Measurement Problem
Creators: name: Wallace, David
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Decoherence is widely felt to have something to do with the quantum measurement problem, but getting clear on just what is made difficult by the fact that the "measurement problem", as traditionally presented in foundational and philosophical discussions, has become somewhat disconnected from the conceptual problems posed by real physics. This, in turn, is because quantum mechanics as discussed in textbooks and in foundational discussions has become somewhat removed from scientific practice, especially where the analysis of measurement is concerned. This paper has two goals: firstly (sections 1-2), to present an account of how quantum measurements are actually dealt with in modern physics (hint: it doesn't involve a collapse of the wavefunction) and to state the measurement problem from the perspective of that account; and secondly (sections 3-4), to clarify what role decoherence plays in modern measurement theory and what effect it has on the various strategies that have been proposed to solve the measurement problem.
description: 10 pages; invited submission to special issue of Phil. Trans. Roy. Soc. Lond. (A. Hagar ed.)
Evaluation of embankment failure at Canadian Pacific Railway mile 34.1 Kaministiguia subdivision
Creators: name: Choi, Eddie Sing Chuen
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: TA760 .C46 1998
subject: Tailings embankments - Alberta
subject: Slopes (Soil mechanics)
subject: Soil stabilization

description: Bibliography: p. 113-116
Signed distributions of real tensor eigenvectors of Gaussian tensor model via a four-fermi theory
Creators: name: Sasakura, Naoki
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Eigenvalue distributions are important dynamical quantities in matrix models, and it is a challenging problem to derive them in tensor models. In this paper, we consider real symmetric order-three tensors with Gaussian distributions as the simplest case, and derive an explicit formula for signed distributions of real tensor eigenvectors: Each real tensor eigenvector contributes to the distribution by $\pm 1$, depending on the sign of the determinant of an associated Hessian matrix. The formula is expressed by the confluent hypergeometric function of the second kind, which is obtained by computing a partition function of a four-fermi theory. The formula can also serve as lower bounds of real eigenvector distributions (with no signs), and their tightness/looseness are discussed by comparing with Monte Carlo simulations. Large-$N$ limits are taken with the characteristic oscillatory behavior of the formula being preserved.
description: 11 pages, 2 figures. Paragraphs added in the introduction, and related references added
History dependence of directly observed magnetocaloric effects in (Mn, Fe)As
Creators: name: Bratko, Milan
name: Morrison, Kelly
name: de Campos, Ariana
name: Gama, Sergio
name: Cohen, Lesley F.
name: Sandeman, Karl G.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We use a calorimetric technique operating in sweeping magnetic field to study the thermomagnetic history- dependence of the magnetocaloric effect (MCE) in Mn0.985Fe0.015As. We study the magnetization history for which a "colossal" MCE has been reported when inferred indirectly via a Maxwell relation. We observe no colossal effect in the direct calorimetric measurement. We further examine the impact of mixed-phase state on the MCE and show that the first order contribution scales linearly with the phase fraction. This validates various phase-fraction based methods developed to remove the colossal peak anomaly from Maxwell-based estimates.
description: 4 pages, 2 figures
Heterotic Line Bundle Standard Models
Creators: name: Anderson, Lara B.
name: Gray, James
name: Lukas, Andre
name: Palti, Eran
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In a previous publication, arXiv:1106.4804, we have found 200 models from heterotic Calabi-Yau compactifications with line bundles, which lead to standard models after taking appropriate quotients by a discrete symmetry and introducing Wilson lines. In this paper, we construct the resulting standard models explicitly, compute their spectrum including Higgs multiplets, and analyze some of their basic properties. After removing redundancies we find about 400 downstairs models, each with the precise matter spectrum of the supersymmetric standard model, with one, two or three pairs of Higgs doublets and no exotics of any kind. In addition to the standard model gauge group, up to four Green-Schwarz anomalous U(1) symmetries are present in these models, which constrain the allowed operators in the four-dimensional effective supergravity. The vector bosons associated to these anomalous U(1) symmetries are massive. We explicitly compute the spectrum of allowed operators for each model and present the results, together with the defining data of the models, in a database of standard models accessible at http://www-thphys.physics.ox.ac.uk/projects/CalabiYau/linebundlemodels/index.html. Based on these results we analyze elementary phenomenological properties. For example, for about 200 models all dimension four and five proton decay violating operators are forbidden by the additional U(1) symmetries.
description: 55 pages, Latex, 3 pdf figures
Model-based Fault Classification for Automotive Software
Creators: name: Becker, Mike
name: Meyer, Roland
name: Runge, Tobias
name: Schaefer, Ina
name: van der Wall, Sören
name: Wolff, Sebastian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Software Engineering (cs.SE)
subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: Intensive testing using model-based approaches is the standard way of demonstrating the correctness of automotive software. Unfortunately, state-of-the-art techniques leave a crucial and labor intensive task to the test engineer: identifying bugs in failing tests. Our contribution is a model-based classification algorithm for failing tests that assists the engineer when identifying bugs. It consists of three steps. (i) Fault localization replays the test on the model to identify the moment when the two diverge. (ii) Fault explanation then computes the reason for the divergence. The reason is a subset of actions from the test that is sufficient for divergence. (iii) Fault classification groups together tests that fail for similar reasons. Our approach relies on machinery from formal methods: (i) symbolic execution, (ii) Hoare logic and a new relationship between the intermediary assertions constructed for a test, and (iii) a new relationship among Hoare proofs. A crucial aspect in automotive software is timing requirements, for which we develop appropriate Hoare logic theory. We also briefly report on our prototype implementation for the CAN bus Unified Diagnostic Services in an industrial project.
Klara Steinweg †
Creators: name: Hueck, Irene
Publisher: name: Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege
Year: 2020

description: Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege, Bd. 25 Nr. 11 (1972): Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege
Spin Hall effect of vorticity
Creators: name: Schwartz, Edward
name: Vakili, Hamed
name: Ali, Moaz
name: Kovalev, Alexey A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using mapping between topological defects in an easy-plane magnet and electrical charges, we study interplay between vorticity and spin currents. We demonstrate that the flow of vorticity is accompanied by the transverse spin current generation -- an effect which can be termed as the spin Hall effect of vorticity. We study this effect across the BKT transition and establish the role of dissipation and spin non-conservation in the crossover from spin superfluidity to diffusive spin transport. Our results pave the way for low power computing devices relying on vorticity and spin flows.
description: 6 pages, 5 figures
Terahertz hot electron bolometer waveguide mixers for GREAT
Creators: name: Pütz, P.
name: Honingh, C. E.
name: Jacobs, K.
name: Justen, M.
name: Schultz, M.
name: Stutzki, J.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Supplementing the publications based on the first-light observations with the German Receiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on their operation in GREAT is given. Our mixer units are waveguide-based and couple to free-space radiation via a feedhorn antenna. The HEB mixers are designed, fabricated, characterized, and flight-qualified in-house. We are able to use the full intermediate frequency bandwidth of the mixers using silicon-germanium multi-octave cryogenic low-noise amplifiers with very low input return loss. Superconducting HEB mixers have proven to be practical and sensitive detectors for high-resolution THz frequency spectroscopy on SOFIA. We show that our niobium-titanium-nitride (NbTiN) material HEBs on silicon nitride (SiN) membrane substrates have an intermediate frequency (IF) noise roll-off frequency above 2.8 GHz, which does not limit the current receiver IF bandwidth. Our mixer technology development efforts culminate in the first successful operation of a waveguide-based HEB mixer at 2.5 THz and deployment for radioastronomy. A significant contribution to the success of GREAT is made by technological development, thorough characterization and performance optimization of the mixer and its IF interface for receiver operation on SOFIA. In particular, the development of an optimized mixer IF interface contributes to the low passband ripple and excellent stability, which GREAT demonstrated during its initial successful astronomical observation runs.
description: Accepted for publication in A&A (SOFIA/GREAT special issue)
Collecting And Preserving Local And Traditional Climate Knowledge
Creators: name: Collins, Julia
name: Pulsifer, Peter L.
name: Gearheard, Shari
Publisher: name: Zenodo
Year: 2011
Subjects: local knowledge
Arctic
climate

description: The Exchange for Local Observations and Knowledge of the Arctic (ELOKA) facilitates the collection, preservation, exchange, and use of local observations and knowledge of the Arctic. Local and Traditional Knowledge (LTK) provides rich information about the Arctic that complements data acquired via conventional quantitative data collection methods. ELOKA seeks to make LTK and community observations discoverable and accessible to community members, scientists, educators, policy makers, and the general public.
Generalizing Boolean Satisfiability III: Implementation
Creators: name: Dixon, H. E.
name: Ginsberg, M. L.
name: Hofer, D.
name: Luks, E. M.
name: Parkes, A. J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: This is the third of three papers describing ZAP, a satisfiability engine that substantially generalizes existing tools while retaining the performance characteristics of modern high-performance solvers. The fundamental idea underlying ZAP is that many problems passed to such engines contain rich internal structure that is obscured by the Boolean representation used; our goal has been to define a representation in which this structure is apparent and can be exploited to improve computational performance. The first paper surveyed existing work that (knowingly or not) exploited problem structure to improve the performance of satisfiability engines, and the second paper showed that this structure could be understood in terms of groups of permutations acting on individual clauses in any particular Boolean theory. We conclude the series by discussing the techniques needed to implement our ideas, and by reporting on their performance on a variety of problem instances.
Stitching pairs of Levy processes into harnesses
Creators: name: Bryc, Wlodek
name: Wesolowski, Jacek
Publisher: name: arXiv
Year: 2011
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G48, 60J99

description: We consider natural exponential families of Levy processes with randomized parameter. Such processes are Markov, and under suitable assumptions, pairs of such processes with shared randomization can be stitched together into a single harness. The stitching consists of deterministic reparametrization of the time for both processes, so that they run on adjacent time intervals, and of the choice of the appropriate law at the boundary. Processes in the Levy-Meixner class have an additional property that they are quadratic harnesses, and in this case stitching constructions produce quadratic harnesses.
Thermodynamical properties of a trapped interacting Bose gas
Creators: name: Yang, Shi-Jie
name: Liu, Yuechan
name: Feng, Shiping
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The thermodynamical properties of interacting Bose atoms in a harmonic potential are studied within the mean-field approximation. For weak interactions, the quantum statistics is equivalent to an ideal gas in an effective mean-field potential. The eigenvalue of the Gross-Pitaevskii equation is identified as the chemical potential of the ideal gas. The condensation temperature and density profile of atoms are calculated. It is found that the critical temperature $T_c$ decreases as the interactions increase. Below the critical point, the condensation fraction exhibits a universal relation of $N_0/N=1-(T/T_c)^γ$, with the index $γ\approx 2.3$ independent of the interaction strength, the chemical potential, as well as the frequency of the confining potential.
description: 5 figures, Accepted by Mod. Phys. Lett. B. arXiv admin note: text overlap with arXiv:cond-mat/0001079 by other authors
Event-Triggered Control for Discrete-Time Delay Systems
Creators: name: Zhang, Kexue
name: Braverman, Elena
name: Gharesifard, Bahman
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This study focuses on event-triggered control of nonlinear discrete-time systems with time delays. Based on a Lyapunov-Krasovskii type input-to-state stability result, we propose a novel event-triggered control algorithm that works as follows. The control inputs are updated only when a certain measurement error surpasses a dynamical threshold depending on both the system states and the evolution time. Sufficient conditions are established to ensure that the closed-loop system maintains its asymptotic stability. It is shown that the time-dependent portion in the dynamical threshold is essential to derive the lower bound of the times between two consecutive control updates. As a special case of our results, we demonstrate the performance of the designed event-triggering algorithm for a class of linear control systems with time delays. Numerical simulations are provided to demonstrate the effectiveness of our algorithm and theoretical results.
Quantum criticality out of equilibrium in the pseudogap Kondo model
Creators: name: Chung, Chung-Hou
name: Zhang, Kenneth Yi-Jie
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We theoretically investigate the non-equilibrium quantum phase transition in a generic setup: the pseudogap Kondo model where a quantum dot couples to two-left (L) and right (R)-voltage-biased fermionic leads with power-law density of states (DOS) with respect to their Fermi levels μ_L/R, ρ_c,L(R) (ω) \propto |ω - μ_L(R) |r, and 0 < r < 1. In equilibrium (zero bias voltage) and for 0 < r < 1/2, with increasing Kondo correlations, in the presence of particle-hole symmetry this model exhibits a quantum phase transition from a unscreened local moment (LM) phase to the Kondo phase. Via a controlled frequency-dependent renormalization group (RG) approach, we compute analytically and numerically the non-equilibrium conductance, conduction electron T-matrix and local spin susceptibility at finite bias voltages near criticality. The current-induced decoherence shows distinct nonequilibrium scaling, leading to new universal non-equilibrium quantum critical behaviors in the above observables. Relevance of our results for the experiments is discussed.
description: 4.1 pages, 2 figures