cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Transverse oscillations of two coronal loops
Creators: name: Luna, M.
name: Terradas, J.
name: Oliver, R.
name: Ballester, J. L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study transverse fast magnetohydrodynamic waves in a system of two coronal loops modeled as smoothed, dense plasma cylinders in a uniform magnetic field. The collective oscillatory properties of the system due to the interaction between the individual loops are investigated from two points of view. Firstly, the frequency and spatial structure of the normal modes are studied. The system supports four trapped normal modes in which the loops move rigidly in the transverse direction. The direction of the motions is either parallel or perpendicular to the plane containing the axes of the loops. Two of these modes correspond to oscillations of the loops in phase, while in the other two they move in antiphase. Thus, these solutions are the generalization of the kink mode of a single cylinder to the double cylinder case. Secondly, we analyze the time-dependent problem of the excitation of the pair of tubes. We find that depending on the shape and location of the initial disturbance, different normal modes can be excited. The frequencies of normal modes are accurately recovered from the numerical simulations. In some cases, because of the simultaneous excitation of several eigenmodes, the system shows beating and the phase lag between the loops is $π/2$.
description: Accepted for publication in The Astrophysical Journal
Discovery of extreme asymmetry in the debris disk surrounding HD 15115
Creators: name: Kalas, Paul
name: Fitzgerald, Michael P.
name: Graham, James R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the first scattered light detection of a dusty debris disk surrounding the F2V star HD 15115 using the Hubble Space Telescope in the optical, and Keck adaptive optics in the near-infrared. The most remarkable property of the HD 15115 disk relative to other debris disks is its extreme length asymmetry. The east side of the disk is detected to ~315 AU radius, whereas the west side of the disk has radius >550 AU. We find a blue optical to near-infrared scattered light color relative to the star that indicates grain scattering properties similar to the AU Mic debris disk. The existence of a large debris disk surrounding HD 15115 adds further evidence for membership in the Beta Pic moving group, which was previously argued based on kinematics alone. Here we hypothesize that the extreme disk asymmetry is due to dynamical perturbations from HIP 12545, an M star 0.5 degrees (0.38 pc) east of HD 15115 that shares a common proper motion vector, heliocentric distance, galactic space velocity, and age.
description: 4 pages, 3 figures, ApJ Letters, accepted
Optimal state in the Knill-Laflamme-Milburn scheme of linear optical teleportation
Creators: name: Grudka, Andrzej
name: Modlawska, Joanna
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss some properties of the Knill-Laflamme-Milburn scheme for quantum teleportation with both maximally and nonmaximally entangled states. We derive the error correction scheme when one performs teleportation with nonmaximally entangled states and we find the probability for perfect teleportation. We show that the maximally entangled state is optimal in such a case. We also show how the error correction scheme can be implemented experimentally when one uses polarization encoding.
description: 4 pages
Cahiers de lexicologie. 1990-1 et 2, n° 56-57
Creators: name: (:Unap)
Publisher: name: Classiques Garnier
Year: 2012
Subjects: subject: Lexique
subject: Lexicographie
subject: Sémantique
subject: Traduction
subject: Linguistique historique

description: Les Cahiers de lexicologie, revue internationale de lexicologie et de lexicographie, s'intéressent au lexique dans ses relations avec les autres composantes de la langue (syntaxe, sémantique, morphologie, phonologie, discours…), tant du point de vue théorique que de leurs applications, notamment pour ce qui concerne le traitement informatique de la langue.
description: The Cahiers de lexicologie, international review of lexicology and lexicography, studies vocabulary in its relation to other aspects of language (syntax, semantics, morphology, phonology, speech...), both from a theoretical point of view and in practical applications, notably concerning computer treatment of language.
The Mathematical Universe
Creators: name: Tegmark, Max
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: I explore physics implications of the External Reality Hypothesis (ERH) that there exists an external physical reality completely independent of us humans. I argue that with a sufficiently broad definition of mathematics, it implies the Mathematical Universe Hypothesis (MUH) that our physical world is an abstract mathematical structure. I discuss various implications of the ERH and MUH, ranging from standard physics topics like symmetries, irreducible representations, units, free parameters, randomness and initial conditions to broader issues like consciousness, parallel universes and Godel incompleteness. I hypothesize that only computable and decidable (in Godel's sense) structures exist, which alleviates the cosmological measure problem and help explain why our physical laws appear so simple. I also comment on the intimate relation between mathematical structures, computations, simulations and physical systems.
description: Replaced to match accepted Found. Phys. version, 31 pages, 5 figs; more details at http://space.mit.edu/home/tegmark/toe.html
Cahiers de lexicologie. 1991-1, n° 58
Creators: name: (:Unap)
Publisher: name: Classiques Garnier
Year: 2012
Subjects: subject: Lexique
subject: Lexicographie
subject: Sémantique
subject: Traduction
subject: Linguistique historique

description: Les Cahiers de lexicologie, revue internationale de lexicologie et de lexicographie, s'intéressent au lexique dans ses relations avec les autres composantes de la langue (syntaxe, sémantique, morphologie, phonologie, discours…), tant du point de vue théorique que de leurs applications, notamment pour ce qui concerne le traitement informatique de la langue.
description: The Cahiers de lexicologie, international review of lexicology and lexicography, studies vocabulary in its relation to other aspects of language (syntax, semantics, morphology, phonology, speech...), both from a theoretical point of view and in practical applications, notably concerning computer treatment of language.
Cahiers de lexicologie. 1999-2, n° 75
Creators: name: (:Unap)
Publisher: name: Classiques Garnier
Year: 2012
Subjects: subject: Lexique
subject: Lexicographie
subject: Sémantique
subject: Traduction
subject: Linguistique historique

description: Les Cahiers de lexicologie, revue internationale de lexicologie et de lexicographie, s'intéressent au lexique dans ses relations avec les autres composantes de la langue (syntaxe, sémantique, morphologie, phonologie, discours…), tant du point de vue théorique que de leurs applications, notamment pour ce qui concerne le traitement informatique de la langue.
description: The Cahiers de lexicologie, international review of lexicology and lexicography, studies vocabulary in its relation to other aspects of language (syntax, semantics, morphology, phonology, speech...), both from a theoretical point of view and in practical applications, notably concerning computer treatment of language.
Testing String Theory with CMB
Creators: name: Kallosh, Renata
name: Linde, Andrei
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Future detection/non-detection of tensor modes from inflation in CMB observations presents a unique way to test certain features of string theory. Current limit on the ratio of tensor to scalar perturbations, r=T/S, is r < 0.3, future detection may take place for r > 10^{-2}-10^{-3}. At present all known string theory inflation models predict tensor modes well below the level of detection. Therefore a possible experimental discovery of tensor modes may present a challenge to string cosmology. The strongest bound on r in string inflation follows from the observation that in most of the models based on the KKLT construction, the value of the Hubble constant H during inflation must be smaller than the gravitino mass. For the gravitino mass in the usual range, m_{3/2} < O(1) TeV, this leads to an extremely strong bound r < 10^{-24}. A discovery of tensor perturbations with r > 10^{-3} would imply that the gravitinos in this class of models are superheavy, m_{3/2} > 10^{13} GeV. This would have important implications for particle phenomenology based on string theory.
description: 13 pages, 2 figures
Deep Learning for Chest X-ray Analysis: A Survey
Creators: name: Sogancioglu, Ecem
name: Çallı, Erdi
name: van Ginneken, Bram
name: van Leeuwen, Kicky G.
name: Murphy, Keelin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Recent advances in deep learning have led to a promising performance in many medical image analysis tasks. As the most commonly performed radiological exam, chest radiographs are a particularly important modality for which a variety of applications have been researched. The release of multiple, large, publicly available chest X-ray datasets in recent years has encouraged research interest and boosted the number of publications. In this paper, we review all studies using deep learning on chest radiographs, categorizing works by task: image-level prediction (classification and regression), segmentation, localization, image generation and domain adaptation. Commercially available applications are detailed, and a comprehensive discussion of the current state of the art and potential future directions are provided.
description: Under review in Medical Image Analysis
EVIDENCIAÇÃO DAS EXIGÊNCIAS DA LEI SARBANES OXLEY NAS EMPRESAS BRASILEIRAS QUE NEGOCIAM ADRs NOS ESTADOS UNIDOS
Creators: name: Melo De Souza, Maíra
name: Rodrigues Vicente, Ernesto Fernando
name: Borba, José Alonso
name: Lunkes, Rogério João
Publisher: name: Revista de Informação Contábil
Year: 2012

description: Para restabelecer a confiança no mercado acionário, em julho de 2002, nos Estados Unidos (EUA) foi sancionada a Lei Sarbanes-Oxley (SOX), exigindo maior evidenciação por parte das empresas de capital aberto. A SOX é uma lei norte-americana, mas também se aplica às empresas brasileiras que emitem American Depositary Receipts (ADRs) na Bolsa de Valores dos Estados Unidos, de acordo com as normas da Securities and Exchange Commission (SEC). O presente estudo tem como objetivo verificar nas empresas brasileiras, listadas na BOVESPA, que negociam ADRs na NYSE, como está o disclosure voluntário, praticado no Brasil, das exigências de divulgação preconizadas pela SOX. Assim, a amostra de pesquisa foi constituída pelas empresas brasileiras listadas na BOVESPA (CVM/Brasil) e na NYSE (SEC/EUA). Para ter uma noção do nível de evidenciação praticado na amostra observada utilizou-se a técnica de análise de conteúdo. Os resultados evidenciaram que cada empresa divulga, por não existir uma obrigatoriedade no Brasil, em seus relatórios o que julga necessário, o que resulta em um grau maior de evidenciação por parte de algumas e um nível baixo, ou inexistente de informações por parte de outras.
description: Revista de Informação Contábil, v. 5, n. 3 (2011): RIC - Revista de Informação Contábil
A symmetric hyperbolic formulation of the vacuum Einstein equations in affine-null coordinates
Creators: name: Ripley, Justin L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a symmetric hyperbolic formulation of the Einstein equations in affine-null coordinates. Giannakopoulos et. al. (arXiv:2007.06419) recently showed that the most commonly numerically implemented formulations of the Einstein equations in affine-null coordinates (and other single-null coordinate systems) are only weakly-but not strongly-hyperbolic. By making use of the tetrad-based Newman-Penrose formalism, our formulation avoids the hyperbolicity problems of the formulations investigated by Giannakopoulos et. al. We discuss a potential application of our formulation for studying gravitational wave scattering.
description: updated to match journal version
Coherent macroscopic quantum tunneling in boson-fermion mixtures
Creators: name: Mozyrsky, D.
name: Martin, I.
name: Timmermans, E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that the cold atom systems of simultaneously trapped Bose-Einstein condensates (BEC's) and quantum degenerate fermionic atoms provide promising laboratories for the study of macroscopic quantum tunneling. Our theoretical studies reveal that the spatial extent of a small trapped BEC immersed in a Fermi sea can tunnel and coherently oscillate between the values of the separated and mixed configurations (the phases of the phase separation transition of BEC-fermion systems). We evaluate the period, amplitude and dissipation rate for $^{23}$Na and $^{40}$K-atoms and we discuss the experimental prospects for observing this phenomenon.
description: 4 pages, 3 figures
A model and method for measuring information system size
Creators: name: Wrigley, Clive Donald
Publisher: name: University of British Columbia
Year: 2010

description: This thesis develops a measurement model and method that allows information system professionals to establish measures of information system size that are accurate and may be established early in the system development life cycle. It reports the results of an empirical investigation into the aspects of requirements and design metrics which lead to the production of source code. The theoretical foundations used to investigate this topic originate in systems theory, models of information systems and organizational theories of structure and complexity. Models of system development are reviewed as they play a key role in our notions of activities to perform during development. By drawing on existing estimating models from software engineering and other sources of practitioner literature, a model to predict development effort was synthesized. Three distinct constructs emerged: 1) system requirements, which drive effort; 2) personnel experience, which can mitigate effort; and 3) technology, which can also mitigate effort. System requirements was chosen to further define and operationalize, since they are the principal source of development complexity and hence system size. An Entity-Relationship and Event approach was taken to establish an early measure of System Requirements size. A theoretical framework of data and process complexity was developed which may be used to initially size a development project based on the information available at the requirements specification and design phases. It is argued that this new approach is more general than existing sizing techniques; namely, Function Points and Lines of Code. This new sizing approach is tested against 26 simple transaction based processing systems developed in FOCUS. An automated Code Analyser was developed to reverse engineer these systems back to their design measures. The personnel and technology variables were held constant for this initial test. For the thesis, only retrospective measurement occurred but it is expected that longitudinal measurement will eventually be possible. Two primary research contributions are seen emanating from this study. First is the development and application of theory to the problem of information system sizing. Second is a method for data collection and analysis which will help the software development industry move towards the goal of system development measurement and evaluation. This will improve planning for, and management of, information systems development.
Supernova constraints on an axion-photon-dark photon interaction
Creators: name: Hook, Anson
name: Marques-Tavares, Gustavo
name: Ristow, Clayton
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the supernova constraints on an axion-photon-dark photon coupling, which can be the leading coupling to dark sector models and can also lead to dramatic changes to axion cosmology. We show that the supernova bound on this coupling has two unusual features. One occurs because the scattering that leads to the trapping regime converts axions and dark photons into each other. Thus, if one of the two new particles is sufficiently massive, both production and scattering become suppressed and the bounds from bulk emission and trapped (area) emission both weaken exponentially and do not intersect. The other unusual feature occurs because for light dark photons, longitudinal modes couple more weakly than transverse modes do. Since the longitudinal mode is more weakly coupled, it can still cause excessive cooling even if the transverse mode is trapped. Thus, the supernova constraints for massive dark photons look like two independent supernova bounds super-imposed on top of each other.
description: body 20 pages, appendix 16 pages, 10 figures
p-Adic Degeneracy of the Genetic Code
Creators: name: Dragovich, Branko
name: Dragovich, Alexandra
Publisher: name: arXiv
Year: 2007
Subjects: subject: Genomics (q-bio.GN)
subject: Information Theory (cs.IT)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Degeneracy of the genetic code is a biological way to minimize effects of the undesirable mutation changes. Degeneration has a natural description on the 5-adic space of 64 codons $\mathcal{C}_5 (64) = \{n_0 + n_1 5 + n_2 5^2 : n_i = 1, 2, 3, 4 \} ,$ where $n_i$ are digits related to nucleotides as follows: C = 1, A = 2, T = U = 3, G = 4. The smallest 5-adic distance between codons joins them into 16 quadruplets, which under 2-adic distance decay into 32 doublets. p-Adically close codons are assigned to one of 20 amino acids, which are building blocks of proteins, or code termination of protein synthesis. We shown that genetic code multiplets are made of the p-adic nearest codons.
description: 11 pages, 1 table. Published in the Proceedings of '4th Summer School in Modern Mathematcal Physics', September 2006, Belgrade (Serbia)
Stars with Photometrically Young Gaia Luminosities Around the Solar System (SPYGLASS) I: Mapping Young Stellar Structures and their Star Formation Histories
Creators: name: Kerr, Ronan
name: Rizzuto, Aaron C.
name: Kraus, Adam L.
name: Offner, Stella S. R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Young stellar associations hold a star formation record that can persist for millions of years, revealing the progression of star formation long after the dispersal of the natal cloud. To identify nearby young stellar populations that trace this progression, we have designed a comprehensive framework for the identification of young stars, and use it to identify $\sim$3$\times 10^4$ candidate young stars within a distance of 333 pc using Gaia DR2. Applying the HDBSCAN clustering algorithm to this sample, we identify 27 top-level groups, nearly half of which have little to no presence in previous literature. Ten of these groups have visible substructure, including notable young associations such as Orion, Perseus, Taurus, and Sco-Cen. We provide a complete subclustering analysis on all groups with substructure, using age estimates to reveal each region's star formation history. The patterns we reveal include an apparent star formation origin for Sco-Cen along a semicircular arc, as well as clear evidence for sequential star formation moving away from that arc with a propagation speed of $\sim$4 km s$^{-1}$ ($\sim$4 pc Myr$^{-1}$). We also identify earlier bursts of star formation in Perseus and Taurus that predate current, kinematically identical active star-forming events, suggesting that the mechanisms that collect gas can spark multiple generations of star formation, punctuated by gas dispersal and cloud regrowth. The large spatial scales and long temporal scales on which we observe star formation offer a bridge between the processes within individual molecular clouds and the broad forces guiding star formation at galactic scales.
description: Accepted to ApJ; 55 pages, 32 figures, 7 tables in two-column AASTEX63 format
Efficiency of thin film photocells
Creators: name: Mozyrsky, D.
name: Martin, I.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a new concept for the design of high-efficiency photocells based on ultra-thin (submicron) semiconductor films of controlled thickness. Using a microscopic model of a thin dielectric layer interacting with incident electromagnetic radiation we evaluate the efficiency of conversion of solar radiation into the electric power. We determine the optimal range of parameters which maximize the efficiency of such photovoltaic element.
description: 5 pages, 3 figures
Random walks on complex networks with first-passage resetting
Creators: name: Huang, Feng
name: Chen, Hanshuang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We study discrete-time random walks on arbitrary networks with first-passage resetting processes. To the end, a set of nodes are chosen as observable nodes, and the walker is reset instantaneously to a given resetting node whenever it hits either of observable nodes. We derive exact expressions of the stationary occupation probability, the average number of resets in the long time, and the mean first-passage time between arbitrary two non-observable nodes. We show that all the quantities can be expressed in terms of the fundamental matrix $\textbf{Z}=(\textbf{I}-\textbf{Q})^{-1}$, where $\textbf{I}$ is the identity matrix and $\textbf{Q}$ is the transition matrix between non-observable nodes. Finally, we use ring networks, 2d square lattices, barbell networks, and Cayley trees to demonstrate the advantage of first-passage resetting in global search on such networks.
description: Accepted by Physical Review E
A Low-mass Cold and Quiescent Core Population in a Massive Star Protocluster
Creators: name: Li, Shanghuo
name: Lu, Xing
name: Zhang, Qizhou
name: Lee, Chang-Won
name: Sanhueza, Patricio
name: Beuther, Henrik
name: Izaskun
name: Jiménez-Serra
name: Qiu, Keping
name: Palau, Aina
name: Feng, Siyi
name: Pillai, Thushara
name: Kim, Kee-Tae
name: Liu, Hong-Li
name: Girart, Josep Miquel.
name: Liu, Tie
name: Wang, Junzhi
name: Wang, Ke
name: Liu, Hauyu Baobab
name: Smith, Howard A.
name: Li, Di
name: Lee, Jeong-Eun
name: Li, Fei
name: Li, Juan
name: Kim, Shinyoung
name: Yue, Nannan
name: Strom, Shaye
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Pre-stellar cores represent the initial conditions of star formation. Although these initial conditions in nearby low-mass star-forming regions have been investigated in detail, such initial conditions remain vastly unexplored for massive star-forming regions. We report the detection of a cluster of low-mass starless and pre-stellar core candidates in a massive star protocluster forming cloud, NGC6334S. With the ALMA observations at a $\sim$0.02 pc spatial resolution, we identified 17 low-mass starless core candidates that do not show any evidence of protostellar activity. These candidates present small velocity dispersions, high fractional abundances of NH$_{2}$D, high NH$_{3}$ deuterium fractionations, and are completely dark in the infrared wavelengths from 3.6 up to 70~$μ$m. Turbulence is significantly dissipated and the gas kinematics are dominated by thermal motions toward these candidates. Nine out of the 17 cores are gravitationally bound, and therefore are identified as pre-stellar core candidates. The embedded cores of NGC6334S show a wide diversity in masses and evolutionary stages.
description: 13 pages, 4 figures, accepted for publication in ApJ Letters
Photometric study and absolute parameters estimation of six totally eclipsing contact binaries
Creators: name: Li, Kai
name: Xia, Qi-Qi
name: Kim, Chun-Hwey
name: Gao, Xing
name: Hu, Shao-Ming
name: Guo, Di-Fu
name: Gao, Dong-Yang
name: Chen, Xu
name: Guo, Ya-Ni
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429 Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-term period decrease. For V1033 Her, a cyclic variation superimposed on the long-term increase was discovered. By comparing the Gaia distances with those calculated by the absolute parameters of 173 contact binaries, we found that Gaia distance can be applied to estimate absolute parameters for most contact binaries. The absolute parameters of our six targets were estimated by using their Gaia distances. The evolutionary status of contact binaries was studied, we found that the A- and W- subtype contact binaries may have different formation channels. The relationship between the spectroscopic and photometric mass ratios for 101 contact binaries was presented. It is discovered that the photometric mass ratios are in good agreement with the spectroscopic ones for almost all the totally eclipsing systems, which is corresponding to the results derived by Pribulla et al. and Terrell & Wilson.
description: 38 pages, 8 figures, and 10 tables, accepted by AJ
Dynamical Formation of Graphene and Graphane Nanoscrolls
Creators: name: Júnior, Marcelo Lopes Pereira
name: Júnior, Luiz Antonio Ribeiro
name: Galvão, Douglas Soares
name: de Sousa, José Moreira
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences
subject: J.2; I.6
subject: 00-xx

description: Carbon nanoscrolls (CNSs) are nanomaterials with geometry resembling graphene layers rolled up into a spiral (papyrus-like) form. Effects of hydrogenation and temperature on the self-scrolling process of two nanoribbons interacting with a carbon nanotube (CNT) have been studied by molecular dynamics simulations for three configurations: (1) graphene/graphene/CNT; (2) graphene/graphane/CNT, and (3) graphane/graphane/CNT. Graphane refers to a fully hydrogenated graphene nanoribbon. Nanoscroll formation is observed for configuration (1) and (2) for temperatures 300-1000 and 300-600 K, respectively, while nanoribbons wrap CNT without nanoscroll formation for configuration (3).
description: 11 pages and 4 figures
The Changing Look Blazar B2 1420+32
Creators: name: Mishra, Hora D.
name: Dai, Xinyu
name: Chen, Ping
name: Cheng, Jigui
name: Jayasinghe, T.
name: Tucker, Michael A.
name: Vallely, Patrick J.
name: Bersier, David
name: Bose, Subhash
name: Do, Aaron
name: Dong, Subo
name: Holoien, Thomas W. S.
name: Huber, Mark E.
name: Kochanek, Christopher S.
name: Liang, Enwei
name: Payne, Anna V.
name: Prieto, Jose
name: Shappee, Benjamin J.
name: Stanek, K. Z.
name: Bhatiani, Saloni
name: Cox, John
name: DeFrancesco, Cora
name: Shen, Zhiqiang
name: Thompson, Todd A.
name: Wang, Junfeng
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Blazars are active galactic nuclei with their relativistic jets pointing toward the observer, with two major sub-classes, the flat spectrum radio quasars and BL Lac objects. We present multi-wavelength photometric and spectroscopic monitoring observations of the blazar, B2 1420+32, focusing on its outbursts in 2018-2020. Multi-epoch spectra show that the blazar exhibited large scale spectral variability in both its continuum and line emission, accompanied by dramatic gamma-ray and optical variability by factors of up to 40 and 15, respectively, on week to month timescales. Over the last decade, the gamma-ray and optical fluxes increased by factors of 1500 and 100, respectively. B2 1420+32 was an FSRQ with broad emission lines in 1995. Following a series of flares starting in 2018, it transitioned between BL Lac and FSRQ states multiple times, with the emergence of a strong Fe pseudo continuum. Two spectra also contain components that can be modeled as single-temperature black bodies of 12,000 and 5,200 K. Such a collection of "changing look" features has never been observed previously in a blazar. We measure gamma-ray-optical and the inter-band optical lags implying emission region separations of less than 800 and 130 gravitational radii respectively. Since most emission line flux variations, except the Fe continuum, are within a factor of 2-3, the transitions between FSRQ and BL Lac classifications are mainly caused by the continuum variability. The large Fe continuum flux increase suggests the occurrence of dust sublimation releasing more Fe ions in the central engine and an energy transfer from the relativistic jet to sub-relativistic emission components.
description: 21 pages, 6 figures
Measuring the dispersion relations of spin wave bands using time-of-flight spectroscopy
Creators: name: Devolder, T.
name: Talmelli, G.
name: Ngom, S. M.
name: Ciubotaru, F.
name: Adelmann, C.
name: Chappert, C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We develop a generic all-inductive procedure to measure the band structure of spin waves in a magnetic thin stripe. In contrast to existing techniques, our method works even if several spin wave branches coexist in the investigated frequency interval, provided that the branches possess sufficiently different group velocities. We first measure the microwave scattering matrix of a network composed of distant antennas inductively coupled to the spin wave bath of the magnetic film. After a mathematical transformation to the time-domain to get the transmission impulse response, the different spin wave branches are viewed as wavepackets that reach successively the receiving antenna after different travel times. In analogy with time-of flight spectroscopy, the wavepackets are then separated by time-gating. The time-gated responses are used to recalculate the contribution of each spin wave branch to the frequency domain scattering matrix. The dispersion relation of each branch stems from the absolute phase of the time-gated transmission parameter. The spin wave wavevector can be determined unambiguously if the results for several propagation distances are combined, so as to get the dispersion relations.
description: Submitted to the PRB. This work was funded through the FETOPEN-01-2016-2017-FET-Open research and innovation actions (CHIRON project: Grant Agreement No. 801055) and was partly supported by the French RENATECH network. This work is also supported by a public grant overseen by ANR as part of the "Investissements d'avenir" program (Labex NanoSaclay, reference: ANR-10-LABX-0035)
Velocity plateaus and jumps in carbon nanotube sliding
Creators: name: Zhang, Xiao-Hua
name: Tartaglino, Ugo
name: Santoro, Giuseppe E.
name: Tosatti, Erio
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The friction between concentric carbon nanotubes sliding one inside the other has been widely studied and simulated, but not so far using external force as the driving variable. Our molecular dynamics (MD) simulations show that as the pulling force grows, the sliding velocity increases by jumps and plateaus rather than continuously as expected. Dramatic friction peaks (similar to that recently noted by Tangney {\it et al.} in Phys. Rev. Lett. 97 (2006) 195901) which develop around some preferential sliding velocities, are at the origin of this phenomenon. The (stable) rising edge of the peak produces a velocity plateau; the (unstable) dropping edge produces a jump to the nearest stable branch. The outcome is reminiscent of conduction in ionized gases, the plateau correspon ding to a current stabilization against voltage variations, the jump corresponding to a discharge or breakdown.
description: 9 pages, 5 color figures, format latex Elsart. Surface Science, in press, http://dx.doi.org/10.1016/j.susc.2007.05.034
title: img journal, No. 9 (2023): Metaverse Dilemma
title: Metaverse Dilemma
titleType: AlternativeTitle
Creators: name: Img Journal
Publisher: name: img journal
Year: 2024

description: Exploring An-Icons, Between Media Archaeology, Cultural History, Memory Studies and Contemporary Applications...40-73
The Dark Zone. Philosophy of the Metaverse. The Cultural Logic of the Algorithmic Society...18-39
Editorial...6-17
Metaphorical Metaverses. The Case of Bunker Architecture...194-215
The Architecture of the Virtual Not-Place. Reflections on Design in the Metaverse...182-193
That Digital Elsewhere, So Impossible to Ignore!...170-181
Metaverse or Urban Digital Twin: That is the Question...160-169
Back to the Metaverse...106-127
VR Applications for Cultural Heritage: Harnessing Proxemics and Interactivity for Heritage Dissemination...74-105
Towards an Atlas of Metaverse in Architecture: Timeline 1980-2023...128-141
Images and Imagination. Dialogues between Art, Architecture, and Urban Space: Videomapping at Vinovo Castle...142-159
Galactic Wind Signatures around High Redshift Galaxies
Creators: name: Kawata, Daisuke
name: Rauch, Michael
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We carry out cosmological chemodynamical simulations with different strengths of supernova (SN) feedback and study how galactic winds from star-forming galaxies affect the features of hydrogen (HI) and metal (CIV and OVI) absorption systems in the intergalactic medium at high redshift. We find that the outflows tend to escape to low density regions, and hardly affect the dense filaments visible in HI absorption. As a result, the strength of HI absorption near galaxies is not reduced by galactic winds, but even slightly increases. We also find that a lack of HI absorption for lines of sight (LOS) close to galaxies, as found by Adelberger et al., can be created by hot gas around the galaxies induced by accretion shock heating. In contrast to HI, metal absorption systems are sensitive to the presence of winds. The models without feedback can produce the strong CIV and OVI absorption lines in LOS within 50 kpc from galaxies, while strong SN feedback is capable of creating strong CIV and OVI lines out to about twice that distance. We also analyze the mean transmissivity of HI, CIV, and OVI within 1 h$^{-1}$ Mpc from star-forming galaxies. The probability distribution of the transmissivity of HI is independent of the strength of SN feedback, but strong feedback produces LOS with lower transmissivity of metal lines. Additionally, strong feedback can produce strong OVI lines even in cases where HI absorption is weak. We conclude that OVI is probably the best tracer for galactic winds at high redshift.
description: 16 pages, 16 figures, ApJ in press. Higher resolution version available at http://www.ociw.edu/~dkawata/research/papers.html
Interpretation of Light-Quenching Factor Measurements
Creators: name: Bavykina, I.
name: Christ, P.
name: Huff, P.
name: Ninkovic, J.
name: Proebst, F.
name: Seidel, W.
name: Stodolsky, L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We observe that the pattern of the quenching factors for scintillation light from various ions, recently studied in $CaWO_4$ in connection with dark matter detectors, can be understood as a saturation phenomenon in which the light output is simply proportional to track length, independent of the ion and its energy. This observation is in accord with the high dE/dx limit of Birks' law. It suggests a simple model for the intrinsic resolution of light detectors for low energy ions, which we briefly discuss.
description: Seven pages, seven figures, some with color
Continuum Coupling and Single-Nucleon Overlap Integrals
Creators: name: Michel, N.
name: Nazarewicz, W.
name: Ploszajczak, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The presence of a particle continuum, both of a resonant and non-resonant character, can significantly impact spectroscopic properties of weakly bound nuclei and excited nuclear states close to, and above, the particle emission threshold. In the framework of the continuum shell model in the complex momentum-plane, the so-called Gamow Shell Model, we discuss salient effects of the continuum coupling on the one-neutron overlap integrals and the associated spectroscopic factors in neutron-rich helium and oxygen nuclei. In particular, we demonstrate a characteristic near-threshold energy dependence of the spectroscopic factors for different l-waves. We show also that the realistic radial overlap functions, which are needed for the description of transfer reactions, can be generated by single-particle wave functions of the appropriately chosen complex potential.
description: 9 figures; 23 pages; corrected version; accepted in Nuclear Physics A
Adaptive control based on orthonormal series representation
Creators: name: Zervos, Christos Constantine
Publisher: name: University of British Columbia
Year: 2010

description: This thesis describes a novel approach to adaptive control systems design using orthonormal series representation. The class of adaptive algorithms considered is that commonly referred to as self-tuning controllers developed for discrete-time systems. A common characteristic of the self-tuning schemes so far studied for industrial applications is that they are usually based on ARMAX models. These existing adaptive control algorithms have been shown to be globally asymptotically stable under certain theoretical assumptions and they have performed well in various applications. These theoretical assumptions are somehow too restrictive from an engineering and practical point of view. Real industrial plants always contain considerable time delays, have unmodeled dynamics, exhibit time varying dynamics and are subject to various disturbances. The purpose of this thesis is to explore a new way of representing and controlling dynamic systems in an effort to find another way, probably better and more robust, to handle a certain class of industrial applications. The behaviour of adaptive controllers in the presence of unmodelled dynamics and in the presence of time-varying plant delays along with the need for reduced a-priori information as dictated by the conditions encountered usually in practice have led us to abandon the usual ARMA transfer function representation for a new representation by orthonormal series. Our new approach is advantageous because it eliminates the need for assumptions about the plant order and the time-delay, i.e. accurate assumptions about their true values are not necessary. A physical dynamical plant, including its time delay, is modelled by an orthonormal set of functions. The sets considered here are mainly the Laguerre set, a modified version of it, and a set based on complex poles. Other orthonormal functions may also be used. A simple predictive control law is proposed from which an adaptive controller is then designed. The schemes developed are explicit and implicit, deterministic and stochastic. Some multivariable schemes are also presented. Simulations of these new controllers show they are easy to use, able to handle non-minimum phase plants, and more robust than the conventional model-based approaches. Results from industrial trials confirm the applicability of these new schemes.
`Stückelberg interferometry' with ultracold molecules
Creators: name: Mark, M.
name: Kraemer, T.
name: Waldburger, P.
name: Herbig, J.
name: Chin, C.
name: Naegerl, H. -C.
name: Grimm, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report on the realization of a time-domain `Stückelberg interferometer', which is based on the internal state structure of ultracold Feshbach molecules. Two subsequent passages through a weak avoided crossing between two different orbital angular momentum states in combination with a variable hold time lead to high-contrast population oscillations. This allows for a precise determination of the energy difference between the two molecular states. We demonstrate a high degree of control over the interferometer dynamics. The interferometric scheme provides new possibilities for precision measurements with ultracold molecules.
description: 4 pages, 5 figures
title: Αποκατάσταση και επανάχρηση της βίλας Κεφαλληνού στο Χαλάνδρι Αττικής
title: Restoration and reuse of vila Kefalinos in Chalandri, Attica
Creators: name: Κουτρουμπιλα Γεωργια
Publisher: name: Technical University of Crete
Year: 2022

description: Η παρούσα διπλωματική εργασία έχει ως αντικείμενο την αποκατάσταση και επανάχρηση της βίλας Κεφαλληνού στο Χαλάνδρι Αττικής, η οποία αποτέλεσε την οικία της οικογένειας των Κεφαλληνών από το 1920 έως και το 2010 οπότε και εγκαταλείφθηκε. Πρόκειται για ένα εκλεκτικιστικό ισόγειο κτίριο με υπόγειο, της εποχής του μεσοπολέμου, το οποίο κηρύχθηκε διατηρητέο το 1999.
Σκοπός της παρούσας εργασίας είναι η αποκατάσταση του κτηρίου, η ανάδειξη  και  επανάχρησή του, σύμφωνα με τις σύγχρονες τάσεις και τους διεθνείς χάρτες για την προστασία και αποκατάσταση των μνημείων. Για τον σκοπό αυτόν, πραγματοποιήθηκε πλήρης ιστορική και αρχιτεκτονική τεκμηρίωση του μνημείου, σύμφωνα με την οποία  αξιολογήθηκε η υφιστάμενη κατάσταση της παθολογίας του, εκτιμήθηκαν οι αξίες που φέρει και προσδιορίστηκαν οι προτεινόμενες επεμβάσεις, με σεβασμό στο μνημείο και τις αξίες του. Μεθοδολογικά η έρευνα βασίστηκε σε δύο σκέλη : α) σε αρχειακό υλικό εμπλεκομένων υπηρεσιών (Πολεοδομίας του Δήμου Αγίας Παρασκευής, Υπουργείο Ενέργειας, Τεχνική Υπηρεσία του Δήμου Χαλανδρίου), βιβλιογραφικό υλικό, προφορικές συνεντεύξεις και β) σε επιτόπια έρευνα και καταγραφή των αρχιτεκτονικών και κατασκευαστικών στοιχείων του ακινήτου.
Η εργασία διαρθρώνεται  σε τρία μέρη. Το πρώτο μέρος αφορά τη σχέση του κτιρίου με την ευρύτερη περιοχή στην οποία αυτό ανήκει και με την οποία συσχετίζεται. Στο δεύτερο μέρος, γίνεται η αρχιτεκτονική τεκμηρίωση του κτιρίου με επιτόπια έρευνα και καταγραφή της τυπολογίας, της μορφολογίας και της παθολογίας, του κλείνοντας με συμπεράσματα για τις αξίες του, οι οποίες θα αποτελέσουν κριτήριο για τον βαθμό επέμβασης. Το τρίτο μέρος, αφορά την πρόταση αποκατάστασης και επανάχρησης, βάσει των δεδομένων που προέκυψαν από τα δυο προηγούμενα κεφάλαια. Η πρόταση στηρίζεται στα κριτήρια που πρέπει να ικανοποιούνται, ούτως ώστε το κτίριο να είναι ικανό να φιλοξενήσει μία χρήση που αφενός θα είναι συμβατή με αυτό και αφετέρου μία χρήση η οποία θα ικανοποιεί και θα ανταποκρίνεται στις ανάγκες της τοπικής κοινωνίας.
Anomalous exchange coupling in transition-metal-oxide based superlattices with antiferromagnetic spacer layers
Creators: name: Padhan, P.
name: Prellier, W.
name: Budhani, R. C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A direct correlation is seen between the coercive field (HC) and the magnetic-field-dependent resistivity (MR) in SrMnO3/SrRuO3 superlattices of perpendicular magnetic anisotropy. The magnetoresistance shows a sharp jump at Hc for in-plane current and the out-of-plane magnetic field. Both HC and high-field MR also oscillate with the thickness of the SrMnO3 spacer layers separating the metallic ruthenate. Since the spacer in these superlattices has no mobile carriers to facilitate an oscillatory coupling, we attribute the observed behavior to the spin-polarized quantum tunneling of electrons between the ferromagnetic layers and antiferromagnetically ordered t2g spins of SrMnO3.
description: Submitted to J. Appl. Phys
An integral field spectroscopic survey for high redshift damped Lyman-alpha galaxies
Creators: name: Christensen, L.
name: Wisotzki, L.
name: Roth, M. M.
name: Sanchez, S. F.
name: Kelz, A.
name: Jahnke, K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We search for galaxy counterparts to damped Lyman-alpha absorbers (DLAs) at z>2 towards nine quasars, which have 14 DLAs and 8 sub-DLAs in their spectra. We use integral field spectroscopy to search for Ly-alpha emission line objects at the redshifts of the absorption systems. Besides recovering two previously confirmed objects, we find six statistically significant candidate Ly-alpha emission line objects. The candidates are identified as having wavelengths close to the DLA line where the background quasar emission is absorbed. In comparison with the six currently known Ly-alpha emitting DLA galaxies the candidates have similar line fluxes and line widths, while velocity offsets between the emission lines and systemic DLA redshifts are larger. The impact parameters are larger than 10 kpc, and lower column density systems are found at larger impact parameters. Assuming that a single gas cloud extends from the QSO line of sight to the location of the candidate emission line, we find that the average candidate DLA galaxy is surrounded by neutral gas with an exponential scale length of ~5 kpc.
description: 19 pages, 10 figures, accepted for publication in Astronomy & Astrophysics
On the relationship between audit risk and security market measures of risk
Creators: name: Stein, Michael T.
Publisher: name: University of British Columbia
Year: 2010

description: This research investigates the relationship between security market measures of risk and audit risk. The auditor's decision making environment is extended to include the actions of the client firm's shareholders. Using the Nash equilibrium concept it is shown that, in equilibrium, the expected costs of auditing increase with the probability of a "bad" outcome in the securities markets. This result obtains in both strict liability and negligence regimes. The result is driven, in part by the insurance role of auditing. In empirical tests an association is established between security risk and audit fees. These tests suggest that security market measures of risk may provide information useful to the auditor in his decision making.