cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Alles online oder Der Weg zum Klick
title: Statement
titleType: Subtitle
Creators: name: Swoboda, Michaela
Publisher: name: Graz University Library Publishing
Year: 2021

description: 75 Jahre VÖB. 1946–2021, Hg. v. Alker-Windbichler, Bauer und Köstner-Pemsel, 2021, S. 255–257
The potential of Optical Coherence Tomography to analyze biofilm architecture
Creators: name: Romeu, Maria João
Publisher: name: Zenodo
Year: 2023
Subjects: Optical Coherence Tomography; Biofilm analysis; Biofilm architecture; Structural parameters.

description: Biofilm science has changed considerably during the last decades due to scientific and technological improvements. However, most imaging methods to analyze biofilms are ex situ and destructive. Optical Coherence Tomography (OCT) is a non-destructive, fast, and real-time approach, allowing biofilm in situ imaging and the measurement of different parameters, such as biofilm thickness and roughness. Despite the advantages of this optical technique, only a limited set of image processing scripts have been specifically developed for processing OCT biofilm images. Since the knowledge of biofilm architecture is important to understand all phenomena related to this complex lifestyle, the development of novel analysis parameters obtained from OCT imaging to evaluate the biofilm structure is of paramount importance.
A set of novel structural parameters obtained from three-dimensional OCT imaging was developed to quantify biofilm structure formed by different organisms, over time and on different surface materials. OCT analysis developed in this work revealed several details of the biofilm structure, including novel qualitative and quantitative data (such as biovolume, porosity, and size of nonconnected pores) that can be useful to evaluate biofilm development and biofouling control strategies in different settings, including food industries and related areas. A deeper knowledge of the biofilm requires a multidisciplinary approach since distinct techniques provide valuable and complementary information about different aspects of the biofilm's complex structure. Since OCT is a promising technique for a deeper understanding of biofilm development, this imaging tool can be applied in food processing environments and industry studies to evaluate the effectiveness of novel antifouling surfaces and physical and chemical mitigation approaches.
title: Publizieren für die VÖB – Erinnerungen eines Redakteurs
title: Statement
titleType: Subtitle
Creators: name: Zwanziger, Roland
Publisher: name: Graz University Library Publishing
Year: 2021

description: 75 Jahre VÖB. 1946–2021, Hg. v. Alker-Windbichler, Bauer und Köstner-Pemsel, 2021, S. 259–261
A Deep Chandra ACIS Study of NGC 4151. III. the Line Emission and Spectral Analysis of the Ionization Cone
Creators: name: Wang, Junfeng
name: Fabbiano, Giuseppina
name: Elvis, Martin
name: Risaliti, Guido
name: Karovska, Margarita
name: Zezas, Andreas
name: Mundell, Carole G.
name: Dumas, Gaelle
name: Schinnerer, Eva
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: This paper is the third in a series in which we present deep Chandra ACIS-S imaging spectroscopy of the Seyfert 1 galaxy NGC 4151, devoted to study its complex circum-nuclear X-ray emission. Emission features in the soft X-ray spectrum of the bright extended emission (L[0.3-2keV]~10^40 erg/s) at r>130 pc (2") are consistent with the brighter OVII, OVIII, and NeIX lines seen in the Chandra HETGS and XMM-Newton RGS spectra below 2 keV. We construct emission line images of these features and find good morphological correlations with the narrow line region clouds mapped in [OIII]5007A. Self-consistent photoionization models provide good descriptions of the spectra of the large scale emission, as well as resolved structures, supporting the dominant role of nuclear photoionization, although displacement of optical and X-ray features implies a more complex medium. Collisionally ionized emission is estimated to be <12% of the extended emission. Presence of both low and high ionization spectral components and extended emission in the X-ray image perpendicular to the bicone indicates leakage of nuclear ionization, likely filtered through warm absorbers, instead of being blocked by a continuous obscuring torus. The ratios of [OIII]/soft X-ray flux are approximately constant (~15) for the 1.5 kpc radius spanned by these measurements, indicating a relatively constant ionization parameter, consistent with the photoionized outflow of a wind-like density profile. Using spatially resolved features, we estimate that the mass outflow rate in NGC 4151 is ~2Msun/yr at 130 pc and the kinematic power of the ionized outflow is 1.7x10^41 erg/s, approximately 0.3% of the bolometric luminosity of NGC 4151.
description: 45 pages. 18 figures. Accepted to ApJ
title: „Frau Dohnal liegt uns in den Ohren, macht Damen mehr zu Direktoren“
title: Die Rolle der Frauen in der VÖB
titleType: Subtitle
Creators: name: Köstner-Pemsel, Christina
Publisher: name: Graz University Library Publishing
Year: 2021

description: 75 Jahre VÖB. 1946–2021, Hg. v. Alker-Windbichler, Bauer und Köstner-Pemsel, 2021, S. 265–284
description: Die Rolle der Frauen in der Vereinigung Österreichischer Bibliothekarinnen und Bibliothekare (VÖB) spiegelt die gesellschaftliche und bibliothekarische Entwicklung der Frauen in Österreich wider. Waren es in den ersten Jahren einzelne herausragende Frauen im Vorstand der VÖB, zeigten sich die frauenpolitischen Veränderungen der 1970er und 1980er Jahre sehr deutlich auch in der Vereinigung. Als äußeres Zeichen kann man die Umbenennung der Vereinigung im Jahr 1992 bezeichnen. Heute ist das Verhältnis von Männern und Frauen im Präsidium ausgeglichen und auch die Stimmgewichtung scheint ausgewogen zu sein.
description: Bibliothekarin, Vereinigung Österreichischer Bibliothekarinnen und Bibliothekare,
Frau, Genderfrage, Österreich
description: The position of women within the Association of Austrian Librarians reflects the development for women in society and libraries in Austria. In the early years of the association, there were only a few outstanding women on the board. A change began to take place in gender politics during the 1970s and 1980s. Today the proportion between women and men and the weighting of votes seems balanced.
description: Association of Austrian Librarians, Librarian, Austria, Gender issues, women
Manipulation and decoherence of acceptor charge qubit in silicon
Creators: name: Song, Y. P.
name: Golding, B.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Dielectric constant and absorption measurements on boron doped silicon samples show that transitions between the acceptor energy levels can be induced by an applied resonant ac electric field and the Stark tuning of level spacing with an external DC electric field. The relatively longer decoherence times were observed by the electric echo measurement in a low boron dopant concentration Si sample. The scalable acceptor-based system is a promising candidate of the charge qubit for quantum computing.
description: This paper has been withdrawn by the author due to a crucial sign error in equation 1 This paper has been withdrawn by the author due to major revision
Electron-phonon interaction effects on the direct gap transitions of nanoscale Si films
Creators: name: Kamineni, Vimal K
name: Diebold, Alain C
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: This study shows that the dielectric function of crystalline Si quantum wells (c-Si QW) is influenced by both carrier confinement and electron-phonon interactions. The energy shifts and lifetime broadening of the excitonic E1 direct gap transition of c-Si QWs from 2 to 10 nm are found to have a significant dimensional and temperature dependence that can be traced to changes in the phonon dispersion of nanoscale films. The influence of electron-phonon interactions on the dielectric function was verified by altering the phonon dispersion using different dielectric layers above a 5 nm c-Si QW.
description: 15 pages, 4 Figure, Appl. Phys. Lett
General framework of the non-perturbative renormalization group for non-equilibrium steady states
Creators: name: Canet, Léonie
name: Chaté, Hugues
name: Delamotte, Bertrand
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This paper is devoted to presenting in detail the non-perturbative renormalization group (NPRG) formalism to investigate out-of-equilibrium systems and critical dynamics in statistical physics. The general NPRG framework for studying non-equilibrium steady states in stochastic models is expounded and fundamental technicalities are stressed, mainly regarding the role of causality and of Ito's discretization. We analyze the consequences of Ito's prescription in the NPRG framework and eventually provide an adequate regularization to encode them automatically. Besides, we show how to build a supersymmetric NPRG formalism with emphasis on time-reversal symmetric problems, whose supersymmetric structure allows for a particularly simple implementation of NPRG in which causality issues are transparent. We illustrate the two approaches on the example of Model A within the derivative expansion approximation at order two, and check that they yield identical results.
description: 28 pages, 1 figure, minor corrections prior to publication
A discrete model of water with two distinct glassy phases
Creators: name: Pagnani, Andrea
name: Pretti, Marco
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate a minimal model for non-crystalline water, defined on a Husimi lattice. The peculiar random-regular nature of the lattice is meant to account for the formation of a random 4-coordinated hydrogen-bond network. The model turns out to be consistent with most thermodynamic anomalies observed in liquid and supercooled-liquid water. Furthermore, the model exhibits two glassy phases with different densities, which can coexist at a first-order transition. The onset of a complex free-energy landscape, characterized by an exponentially large number of metastable minima, is pointed out by the cavity method, at the level of 1-step replica symmetry breaking.
description: expanded version: 6 pages, 7 figures
Quantum Diffusive Dynamics of Macromolecular Transitions
Creators: name: Beccara, S. a
name: Garberoglio, G.
name: Faccioli, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chemical Physics (physics.chem-ph)
subject: Biomolecules (q-bio.BM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We study the role of quantum fluctuations of atomic nuclei in the real-time dynamics of non-equilibrium macro-molecular transitions. To this goal we introduce an extension of the Dominant Reaction Pathways (DRP) formalism, in which the quantum corrections to the classical overdamped Langevin dynamics are rigorously taken into account to order h^2 . We first illustrate our approach in simple cases, and compare with the results of the instanton theory. Then we apply our method to study the C7_eq to C7_ax transition of alanine dipeptide. We find that the inclusion of quantum fluctuations can significantly modify the reaction mechanism for peptides. For example, the energy difference which is overcome along the most probable pathway is reduced by as much as 50%.
description: Final version, to appear in the Journal of Chemical Physics
Enriched weakness
Creators: name: Lack, Stephen
name: Rosicky, Jiri
Publisher: name: arXiv
Year: 2010
Subjects: subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18D20, 18C35, 18G55

description: The basic notions of category theory, such as limit, adjunction, and orthogonality, all involve assertions of the existence and uniqueness of certain arrows. Weak notions arise when one drops the uniqueness requirement and asks only for existence. The enriched versions of the usual notions involve certain morphisms between hom-objects being invertible; here we introduce enriched versions of the weak notions by asking that the morphisms between hom-objects belong to a chosen class of "surjections". We study in particular injectivity (weak orthogonality) in the enriched context, and illustrate how it can be used to describe homotopy coherent structures.
description: 25 pages; v2 minor changes, to appear in JPAA
Gapless excitations in the Haldane-Rezayi state: The thin torus limit
Creators: name: Seidel, Alexander
name: Yang, Kun
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the thin torus limit of the Haldane-Rezayi state. Eight of the ten ground states are found to assume a simple product form in this limit, as is known to be the case for many other quantum Hall trial wave functions. The two remaining states have a somewhat unusual thin torus limit, where a "broken" pair of defects forming a singlet is completely delocalized. We derive these limits from the wave functions on the cylinder, and deduce the dominant matrix elements of the thin torus hollow-core Hamiltonians. We find that there are gapless excitations in the thin torus limit. This is in agreement with the expectation that local Hamiltonians stabilizing wave functions associated with non-unitary conformal field theories are gapless. We also use the thin torus analysis to obtain explicit counting formulas for the zero modes of the hollow-core Hamiltonian on the torus, as well as for the parent Hamiltonians of several other paired and related quantum Hall states.
description: published version, more discussion added, some typos fixed
Mean field solutions of kinetic exchange opinion models
Creators: name: Biswas, Soumyajyoti
Publisher: name: arXiv
Year: 2011
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We present here the exact solution of an infinite range, discrete, opinion formation model. The model shows an active-absorbing phase transition, similar to that numerically found in its recently proposed continuous version (Lallouache et al., Phys. Rev E 82, 056112 (2010)). Apart from the two-agent interactions here we also report the effect of having three agent interactions. The phase diagram has a continuous transition line (two agent interaction dominated) and a discontinuous transition line (three agent interaction dominated) separated by a tricritical point.
description: 9 pages, 7 eps figs
International Network Initiative on Safe and Sustainable Nanotechnologies (INISS-nano)
Creators: name: Falk, Andreas
Publisher: name: Zenodo
Year: 2021
Subjects: safety
sustainability
nano
network
global collaboration

description: This concept paper shall prepare the ecosystem for global collaboration in selected fields of action (see pillars), enabling “collaboration without borders” within joint projects, joint funding initiatives, and any further way of cooperation. Based on the idea of a “network of networks”, the “international network initiative on safe and sustainable nanotechnology” (INISS-nano) was formed, aiming to bring together science, industry and government from partners all over the world, not duplicating structures but connecting with them (e.g. NSC, ANF, EC & JRC, EU-US-CoR’s, standardisation bodies (such as CEN, ISO, ASTM, etc.), OECD & BIAC, ECHA). The focus shall be on the collaboration in different fields pertaining to nanotechnology research in general and nano-safety research in particular. This shall include collaboration in terms of e.g. training, standardisation efforts, test-guidelines development, metrology, commercialisation, ethical aspects, sustainability, and joint research, supporting governance, regulatory guidance, and of course being open for further joint working items.
INISS-Nano: revised concept and action plan (International Network Initiative on Safe and Sustainable Nanotechnologies)
Creators: name: Falk, Andreas
name: Pogany, Alexander
name: Aungkavattana, Pavadee
name: Bañares, Miguel A.
name: Beitollahi, Ali
name: Bim, Vinicius
name: Briffa, Sophie
name: Bochon, Anthony
name: Cassee, Flemming
name: Doridot, Fernand
name: Exner, Thomas
name: Farias, Patricia M.A.
name: Favre, Georges
name: Franzese, Giancarlo
name: Friedrichs, Steffi
name: Hristozov, Danail
name: Hunt, Neil
name: Indaraprasirt, Ramjitti
name: Karim, Md. E.
name: Khandelwal, Neha
name: Malsch, Ineke
name: Marcoulaki, Effie
name: Marjovi, Ali
name: Rasmussen, Kirsten
name: Rocca, Cris
name: Singh, Pushplata Prasad
name: Thongkam, Waluree
name: Tsuruoka, Shuji
name: Wilkens, Terence A.
Publisher: name: Zenodo
Year: 2022
Subjects: safety
sustainability
nano
network
global collaboration

description: The “international network initiative on safe and sustainable nanotechnology” (INISS-nano) is focussing on the collaboration in different fields pertaining to nanotechnology research in general and nano-safety research in particular. This shall include collaboration in terms of e.g., training, standardisation efforts, test-guidelines development, metrology, commercialisation, ethical aspects, respsonible science and research, sustainability, and joint research, supporting governance, regulatory guidance, and of course being open for further joint working items. This document is a revision of the first version (which has been published in June 2021) and shows descriptions and an action plan for each of the pillars: Harmonization Support industrial understanding Sharing / facilitate sharing of resources / infrastructures International collaboration on ethical and societal aspects of nanotechnology
The GMRT-EoR Experiment: A new upper limit on the neutral hydrogen power spectrum at z~8.6
Creators: name: Paciga, Gregory
name: Chang, Tzu-Ching
name: Gupta, Yashwant
name: Nityanada, Rajaram
name: Odegova, Julia
name: Pen, Ue-Li
name: Peterson, Jeffrey
name: Roy, Jayanta
name: Sigurdson, Kris
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a new upper limit to the 21cm power spectrum during the Epoch of Reionization (EoR) which constrains reionization models with an unheated IGM. The GMRT-EoR experiment is an ongoing effort to make a statistical detection of the power spectrum of 21cm neutral hydrogen emission at redshift z~9. Data from this redshift constrain models of the EoR, the end of the Dark Ages arising from the formation of the first bright UV sources, probably stars or mini-quasars. We present results from approximately 50 hours of observations at the Giant Metrewave Radio Telescope in India from December 2007. We describe radio frequency interference (RFI) localisation schemes which allow bright sources on the ground to be identified and physically removed in addition to automated flagging. Singular-value decomposition is used to remove remaining broadband RFI by identifying ground sources with large eigenvalues. Foregrounds are modelled using a piecewise linear filter and the power spectrum is measured using cross-correlations of foreground subtracted images.
description: 11 pages, 11 figures, accepted for publication in MNRAS
Well-balanced Levy Driven Ornstein-Uhlenbeck Processes
Creators: name: Schnurr, Alexander
name: Woerner, Jeannette H. C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G10, 60E07, 91B24

description: In this paper we introduce the well-balanced Lévy driven Ornstein-Uhlenbeck process as a moving average process of the form $X_t=\int \exp(-λ|t-u|)dL_u$. In contrast to Lévy driven Ornstein-Uhlenbeck processes the well-balanced form possesses continuous sample paths and an autocorrelation function which is decreasing not purely exponential but of the order $λ|u|\exp(-λ|u|)$. Furthermore, depending on the size of $λ$ it allows both for positive and negative correlation of increments. We indicate how the well-balanced Ornstein-Uhlenbeck process might be used as mean or volatility process in stochastic volatility models.
description: 16 pages, 2 figure
Generalized second law of thermodynamics in modified FRW cosmology with corrected entropy-area relation
Creators: name: Karami, K.
name: Sheykhi, A.
name: Sahraei, N.
name: Ghaffari, S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Using the corrected entropy-area relation motivated by the loop quantum gravity, we investigate the validity of the generalized second law of thermodynamics in the framework of modified FRW cosmology. We consider a non-flat universe filled with an interacting viscous dark energy with dark matter and radiation. The boundary of the universe is assumed to be the dynamical apparent horizon. We find out that the generalized second law is always satisfied throughout the history of the universe for any spatial curvature regardless of the dark energy model.
description: 9 pages, accepted for publication in Europhysics Letters
Finite-size scaling in two-dimensional Ising spin glass models
Creators: name: Toldin, Francesco Parisen
name: Pelissetto, Andrea
name: Vicari, Ettore
Publisher: name: arXiv
Year: 2011
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the finite-size behavior of two-dimensional spin-glass models. We consider the +-J model for two different values of the probability of the antiferromagnetic bonds and the model with Gaussian distributed couplings. The analysis of renormalization-group invariant quantities, the overlap susceptibility, and the two-point correlation function confirms that they belong to the same universality class. We analyze in detail the standard finite-size scaling limit in terms of TL^(1/nu) in the +-J model. We find that it holds asymptotically. This result is consistent with the low-temperature crossover scenario in which the crossover temperature, which separates the universal high-temperature region from the discrete low-temperature regime, scales as T_c(L) ~ L^(-theta_S) with theta_S \approx 0.5.
description: v2: added fig. 9b; 16 pages, 20 figs
Higher Spin Black Holes
Creators: name: Gutperle, Michael
name: Kraus, Per
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study classical solutions of three dimensional higher spin gravity in the Chern-Simons formulation. We find solutions that generalize the BTZ black hole and carry spin-3 charge. The black hole entropy formula yields a result for the asymptotic growth of the partition function at finite spin-3 chemical potential. Along the way, we develop technology for computing AdS/CFT correlation functions involving higher spin operators.
description: 28 pages, harvmac, no figures v4: corrected statement about asymptotic boundary behavior, new appendix with example of obtaining black hole thermodynamics from integrability v5: sign in eq 4.7 and 4.9 corrected
The LBA Calibrator Survey of southern compact extragalactic radio sources - LCS1
Creators: name: Petrov, Leonid
name: Phillips, Chris
name: Bertarini, Alessandra
name: Murphy, Tara
name: Sadler, Elaine M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We present a catalogue of positions and correlated flux densities of 410 flat-spectrum, compact extragalactic radio sources, previously detected in the AT20G survey. The catalogue spans the declination range -90deg, -40deg and was constructed from four 24 hour VLBI observing sessions with the Australian Long Baseline Array made at 8.3 GHz. The detection rate in these experiments is 97%. The median uncertainty of source positions is 2.6 mas, the median correlated flux density at baseline projections lengths longer than 1000 km is 0.14 Jy. The goal of this work is 1) to provide a pool of sources with positions known at the milliarcsecond level of accuracy that are needed for phase referencing observations, for geodetic VLBI, and for space navigation; 2) to extend the complete flux-limited sample of compact extragalactic sources to the southern hemisphere; and 3) to investigate parsec-scale properties of high-frequency selected sources from the AT20G survey. As a result of the campaign, the number of compact radio sources with declinations < -40deg detectable with VLBI with measured correlated flux densities and positions known with the milliarcsec level of accuracies increased by a factor of 3.5. The catalogue and supporting material is available at http://astrogeo.org/lcs1 .
description: Published Monthly Notices of the Royal Astronomical Society; 13 pages; 3 electronic tables can be found in the source of this submission. In order to get the electronic tables, you need to select "Download Other format" option and download tar.gz source code. Version 2 is updated for reviewer comments and corresponds to the printed version
Finite size effects in nonequilibrium wetting
Creators: name: Barato, Andre Cardoso
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Models with a nonequilibrium wetting transition display a transition also in finite systems. This is different from nonequilibrium phase transitions into an absorbing state, where the stationary state is the absorbing one for any value of the control parameter in a finite system. In this paper, we study what kind of transition takes place in finite systems of nonequilibrium wetting models. By solving exactly a microscopic model with three and four sites and performing numerical simulations we show that the phase transition taking place in a finite system is characterized by the average interface height performing a random walk at criticality and does not discriminate between the bounded-KPZ classes and the bounded-EW class. We also study the finite size scaling of the bKPZ universality classes, showing that it presents peculiar features in comparison with other universality classes of nonequilibrium phase transitions.
description: 14 pages, 6figures, major changes
Differential Privacy: on the trade-off between Utility and Information Leakage
Creators: name: Alvim, Mário S.
name: Andrés, Miguel E.
name: Chatzikokolakis, Konstantinos
name: Degano, Pierpaolo
name: Palamidessi, Catuscia
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cryptography and Security (cs.CR)
subject: Databases (cs.DB)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Differential privacy is a notion of privacy that has become very popular in the database community. Roughly, the idea is that a randomized query mechanism provides sufficient privacy protection if the ratio between the probabilities that two adjacent datasets give the same answer is bound by e^epsilon. In the field of information flow there is a similar concern for controlling information leakage, i.e. limiting the possibility of inferring the secret information from the observables. In recent years, researchers have proposed to quantify the leakage in terms of Rényi min mutual information, a notion strictly related to the Bayes risk. In this paper, we show how to model the query system in terms of an information-theoretic channel, and we compare the notion of differential privacy with that of mutual information. We show that differential privacy implies a bound on the mutual information (but not vice-versa). Furthermore, we show that our bound is tight. Then, we consider the utility of the randomization mechanism, which represents how close the randomized answers are, in average, to the real ones. We show that the notion of differential privacy implies a bound on utility, also tight, and we propose a method that under certain conditions builds an optimal randomization mechanism, i.e. a mechanism which provides the best utility while guaranteeing differential privacy.
description: 30 pages; HAL repository
Equilibrium configurations from gravitational collapse
Creators: name: Joshi, Pankaj S.
name: Malafarina, Daniele
name: Narayan, Ramesh
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the collapsing fluid is supported only by tangential pressure. We show that the equilibrium geometries generated by this method form a subset of static solutions to the Einstein equations, and that they can either be regular or develop a naked singularity at the center. When a singularity is present, there are key differences in the properties of stable circular orbits relative to those around a Schwarzschild black hole with the same mass. Therefore, if an accretion disk is present around such a naked singularity it could be observationally distinguished from a disk around a black hole.
description: 13 pages, 3 figure. Replaced with published version, several changes made according to referee's advise
Strings of group endomorphisms
Creators: name: Dikranjan, Dikran
name: Bruno, Anna Giordano
name: Virili, Simone
Publisher: name: arXiv
Year: 2010
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics

description: Recently the strings and the string number of self-maps were used in the computation of the algebraic entropy of special group endomorphisms. We introduce two special kinds of strings, and their relative string numbers. We show that a dichotomy holds for all these three string numbers; in fact, they admit only zero and infinity as values on group endomorphisms.
description: 17 pages
Exact constraints on D$\leq 10$ Myers Perry black holes and the Wald Problem
Creators: name: Doukas, Jason
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Exact relations on the existence of event horizons of Myers Perry black holes are obtained in $D\leq 10$ dimensions. It is further shown that naked singularities can not be produced by "spinning-up" these black holes by shooting particles into their $\lfloor\frac{D-1}{2}\rfloor$ equatorial planes.
description: 7 pages, 11 figures, version two corrects an earlier error in equation (35) and adds some plots for cohomogeneity-2 and 3 black holes
The impact of weather on ALMA operations
Creators: name: Nowajewski, Priscilla
Publisher: name: Zenodo
Year: 2023

description: ALMA, located in the Chilean Altiplano at the Atacama Desert, faces significant challenges due to extreme weather conditions and seasonal and daily variations. Besides the impact of winds and PWV, the observatory is subject to weather phenomena associated with ENSO, including the Altiplanic winter during the southern hemisphere summer and the Chilean winter during the winter hemisphere. These seasonal variations introduce additional complexities for observatory operations.
This research characterizes the past ten years' weather and climate at the Atacama Large Millimeter/submillimeter Array (ALMA) observatory and their impact on radio astronomy operations. The characterization considers the El Niño-Southern Oscillation (ENSO), and its impact on the intensity of both Altiplanic and Chilean winter. The methodology involves the analysis of in-situ weather station data, numerical forecasts, and considerations for optimizing observatory operations.
In particular, we examine the role of precipitable water vapor and phase rms as crucial factors affecting radio astronomy observations.
In conclusion, this study emphasizes the impact on operations due to weather variables and the climatology of Altiplano. Considering ENSO, Altiplanic, and Chilean winters, the changes in Phase RMS and the amount of precipitable water vapor add further insights into the complexities faced by ALMA in optimizing observatory operations. The findings from this study can aid in developing strategies to mitigate the effects of daily and seasonal variations of weather variables, ensuring optimal performance and data quality in radio astronomy observations at the ALMA observatory.
Stress-deformation analysis of Denis-Perron dam : verification and validation for better prediction of rockfill response
Creators: name: Kolev, Boris Nikolaev
Publisher: name: University of British Columbia
Year: 2018

description: Rockfill dams present a challenge for engineers due to the many uncertainties revolving around the behaviour of rockfill. A governing factor in the behaviour of rockfill is the particle breakage due to change of moisture, which was observed in laboratory and field conditions. Alonso and Oldecop have proposed a rockfill model (RM), where the suction inside the cracks of the rockfill is a state variable that controls the breakage mechanism. This research focuses on verification and validation of stress-deformation analysis methodologies, for better prediction of rockfill response. It involves application of the RM in numerical simulation of a benchmark case study on the well instrumented Denis-Perron dam (SM3). Denis-Perron dam is a rockfill dam with a central till core, 171 metres high and 378 metres long, located on the Sainte-Marquerite river in northern Quebec, Canada. The instrumentation data was made available by Hydro-Qu´ebec, for a period of six years of construction, impoundment, and operation of the dam. Numerical simulations are conducted using Code Bright – a fully coupled three phase finite element program for unsaturated porous media. A validation stage was first carried out through modelling of Beliche dam – a well studied case by Alonso et al. The numerical model of the SM3 dam captures the staged construction, reservoir impoundment and rainfall history recorded. Model parameters for the till core and rockfill shoulders were either calibrated using limited available laboratory and field data, adopted from literature, or assumed with some rationale. Deformations measured by the inclinometers during construction and impoundment, both upstream and downstream, are simulated successfully. Piezometer and pressure cell measurements are replicated to a very good extent. Post-construction deformations are reproduced with reasonable success, given the limited data for detailed characterization of the various zones in the dam. Some important challenges around characterization of the rockfill compressibility and the related scaling issues for model calibration are presented and discussed. An attempt is made to quantify the amount of scaling observed through a back analysis of field measurements. Finally, the effect of permeability on rockfill in the development of deformations is discussed.
Criterions for locally dense subgraphs
Creators: name: Tibély, Gergely
Publisher: name: arXiv
Year: 2011
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Community detection is one of the most investigated problems in the field of complex networks. Although several methods were proposed, there is still no precise definition of communities. As a step towards a definition, I highlight two necessary properties of communities, separation and internal cohesion, the latter being a new concept. I propose a local method of community detection based on two-dimensional local optimization, which I tested on common benchmarks and on the word association database.
description: Revised version. 26 pages, 8 figures, 1 table
A Characterization of Entropy in Terms of Information Loss
Creators: name: Baez, John C.
name: Fritz, Tobias
name: Leinster, Tom
Publisher: name: arXiv
Year: 2011
Subjects: subject: Information Theory (cs.IT)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: 94A17, 62B10

description: There are numerous characterizations of Shannon entropy and Tsallis entropy as measures of information obeying certain properties. Using work by Faddeev and Furuichi, we derive a very simple characterization. Instead of focusing on the entropy of a probability measure on a finite set, this characterization focuses on the `information loss', or change in entropy, associated with a measure-preserving function. Information loss is a special case of conditional entropy: namely, it is the entropy of a random variable conditioned on some function of that variable. We show that Shannon entropy gives the only concept of information loss that is functorial, convex-linear and continuous. This characterization naturally generalizes to Tsallis entropy as well.
description: 11 pages LaTeX, minor revision
Cosmic Magnetic Lenses
Creators: name: Battaner, E.
name: Castellano, J.
name: Masip, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Magnetic fields play a critical role in the propagation of charged cosmic rays. Particular field configurations supported by different astrophysical objects may be observable in cosmic ray maps. We consider a simple configuration, a constant azimuthal field in a disk-like object, that we identify as a cosmic magnetic lens. Such configuration is typical in most spiral galaxies, and we assume that it can also appear at smaller or larger scales. We show that the magnetic lens deflects cosmic rays in a regular geometrical pattern, very much like a gravitational lens deflects light but with some interesting differences. In particular, the lens acts effectively only in a definite region of the cosmic-ray spectrum, and it can be convergent or divergent depending on the (clockwise or counterclockwise) direction of the magnetic field and the (positive or negative) electric charge of the cosmic ray. We find that the image of a point-like monochromatic source may be one, two or four points depending on the relative position of source, observer and center of the lens. For a perfect alignment and a lens in the orthogonal plane the image becomes a ring. We also show that the presence of a lens could introduce low-scale fluctuations and matter-antimatter asymmetries in the fluxes from distant sources. The concept of cosmic magnetic lens that we introduce here may be useful in the interpretation of possible patterns observed in the cosmic ray flux at different energies.
description: 12 pages, version to appear in Astron. Astrophys
Detailed monitoring of the water vapor maser in the binary protostellar system of solar masses IRAS 16293-2422
Creators: name: Volvach, A.E.
name: Volvach, L.N.
name: LArionov, M.G.
Publisher: name: Zenodo
Year: 2021
Subjects: stars: formation –HII regions – ISM: molecules – radio lines: ISM.

description: Detailed monitoring of the water vapor maser in the binary protostellar system of solar masses IRAS 16293-2422

 A. E. Volvach 1, L. N. Volvach 1, M. G. Larionov 2

 1 Radio Astronomy of Crimean Astrophysical Observatory RAS, Katsively, Crimea
 2 Astro Space Center, Lebedev Physical Institute RAS, Moscow Unique results of detailed (one-two days interval between data) one-year monitoring of the young binary system IRAS 16293-2422, performed on the RT-22 radio telescope (Simeiz), are obtained. For the first time, a short, powerful flare of a water vapor maser was recorded (feature +8 km/s), which is a combination of three components. New data on the parameters of the medium in which maser radiation is formed was obtained.
A classification (uniqueness) theorem for rotating black holes in 4D Einstein-Maxwell-dilaton theory
Creators: name: Yazadjiev, Stoytcho S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In the present paper we prove a classification (uniqueness) theorem for stationary, asymptotically flat black hole spacetimes with connected and non-degenerate horizon in 4D Einstein-Maxwell-dilaton theory with an arbitrary dilaton coupling parameter $α$. We show that such black holes are uniquely specified by the length of the horizon interval, angular momentum, electric and magnetic charge and the value of the dilaton field at infinity when the dilaton coupling parameter satisfies $0\le α^2\le3$. The proof is based on the nonpositivity of the Riemann curvature operator on the space of the potentials. A generalization of the classification theorem for spacetimes with disconnected horizons is also given.
description: 15 pages, v2 typos corrected
Adiabatic Spectra During Slowly Evolving
Creators: name: Piao, Yun-Song
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In general, for single field, the scale invariant spectrum of curvature perturbation can be given by either its constant mode or its increasing mode. We show that during slowly expanding or contracting, the spectrum of curvature perturbation given by its increasing mode can be scale invariance. The perturbation mode can be naturally extended out of horizon, and the amplitude of perturbation is consistent with the observations. We briefly discuss the implement of this scenario.
description: 3 pages, 1 figure, arguments, discussions and Refs. added, to publish in PLB
Topological p_x+ip_y Superfluid Phase of Fermionic Polar Molecules
Creators: name: Levinsen, J.
name: Cooper, N. R.
name: Shlyapnikov, G. V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We discuss the topological p_x+ip_y superfluid phase in a 2D gas of single-component fermionic polar molecules dressed by a circularly polarized microwave field. This phase emerges because the molecules may interact with each other via a potential V_0(r) that has an attractive dipole-dipole 1/r^3 tail, which provides p-wave superfluid pairing at fairly high temperatures. We calculate the amplitude of elastic p-wave scattering in the potential V_0(r) taking into account both the anomalous scattering due to the dipole-dipole tail and the short-range contribution. This amplitude is then used for the analytical and numerical solution of the renormalized BCS gap equation which includes the second order Gor'kov-Melik-Barkhudarov corrections and the correction related to the effective mass of the quasiparticles. We find that the critical temperature T_c can be varied within a few orders of magnitude by modifying the short-range part of the potential V_0(r). The decay of the system via collisional relaxation of molecules to dressed states with lower energies is rather slow due to the necessity of a large momentum transfer. The presence of a constant transverse electric field reduces the inelastic rate, and the lifetime of the system can be of the order of seconds even at 2D densities ~ 10^9 cm^{-2}. This leads to T_c of up to a few tens of nanokelvins and makes it realistic to obtain the topological p_x+ip_y phase in experiments with ultracold polar molecules.
description: 15 pages, 9 figures, published version
Gravitational fragmentation in turbulent primordial gas and the initial mass function of Population III stars
Creators: name: Clark, Paul C.
name: Glover, Simon C. O.
name: Klessen, Ralf S.
name: Bromm, Volker
Publisher: name: arXiv
Year: 2010
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report results from numerical simulations of star formation in the early universe that focus on the dynamical behavior of metal-free gas under different initial and environmental conditions. In particular we investigate the role of turbulence, which is thought to ubiquitously accompany the collapse of high-redshift halos. We distinguish between two main cases: the birth of Population III.1 stars - those which form in the pristine halos unaffected by prior star formation - and the formation of Population III.2 stars - those forming in halos where the gas is still metal free but has an increased ionization fraction. This latter case can arise either from exposure to the intense UV radiation of stellar sources in neighboring halos, or from the high virial temperatures associated with the formation of massive halos, that is, those with masses greater than 1e8 solar masses. We find that turbulent primordial gas is highly susceptible to fragmentation in both cases, even for turbulence in the subsonic regime, i.e. for rms velocity dispersions as low as 20 % of the sound speed. Contrary to our original expectations, fragmentation is more vigorous and more widespread in pristine halos compared to pre-ionized ones. We therefore predict Pop III.1 stars to be on average of somewhat lower mass, and form in larger groups, than Pop III.2 stars. We find that fragment masses cover over two orders of magnitude, indicating that the resulting Population III initial mass function was significantly extended in mass as well. This prompts the need for a large, high-resolution study of the formation of dark matter minihalos that is capable of resolving the turbulent flows in the gas at the moment when the baryons become self-gravitating. This would help determine which, if any, of the initial conditions presented in our study are realized in nature.
description: Accepted for publication in ApJ
A Surface pCO2 Increasing Hiatus in the Equatorial Pacific Ocean Since 2010 (Data Analysis Code)
Creators: name: Shuang, Qiu
Publisher: name: Zenodo
Year: 2021

description: This is code and processed data for GRL "A Surface pCO2 Increasing Hiatus in the Equatorial Pacific Ocean Since 2010" It includes a processed pCO2 dataset for analysis (grl_tropicalpCO2_data.mat); code for eof analysis (eof_code.m), fft (fft_code.m), lowpass filter (lp.m; lp_code.m)