cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Planetary nebulae with Wolf-Rayet-type central stars -- III. A detailed view of NGC 6905 and its central star
Creators: name: Gómez-González, V. M. A.
name: Rubio, G.
name: Toalá, J. A.
name: Guerrero, M. A.
name: Sabin, L.
name: Todt, H.
name: Gómez-Llanos, V.
name: Ramos-Larios, G.
name: Mayya, Y. D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present a multi-wavelength characterisation of the planetary nebula (PN) NGC 6905 and its [Wolf-Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope (NOT) Alhambra Faint Object Spectrograph and Camera (ALFOSC) spectra and images unveil in unprecedented detail the high-ionization structure of NGC 6905. The high-quality spectra of HD 193949 allowed us to detect more than 20 WR features including the characteristic O-bump, blue bump and red bump, which suggests a spectral type no later than a [WO2]-subtype. Moreover we detect the Ne VII and Ne VIII broad emission lines, rendering HD 193949 yet another CSPN with $T_\mathrm{eff}\lesssim150$ kK exhibiting such stellar emission lines. We studied the physical properties ($T_\mathrm{e}$ and $n_\mathrm{e}$) and chemical abundances of different regions within NGC 6905 including its low-ionization clumps; abundances are found to be homogeneous. We used the PoWR stellar atmosphere code to model the spectrum of HD 193949, which is afterwards used in a photoionization model performed with Cloudy that reproduces the nebular and dust properties for a total mass in the 0.31-0.47 M$_{\odot}$ range and a mass of C-rich dust of $\sim$2 $\times10^{-3}$ M$_{\odot}$. Adopting a current stellar mass of 0.6 M$_{\odot}$, our model suggests an initial mass $\sim$1 M$_\odot$ for HD 193949, consistent with the observations.
description: To appear in MNRAS; 17 pages, 9 figures, 10 tables
Scritture e scrittori dell’attesa tra Medioevo e Rinascimento
Creators: name: Modesti, Maddalena
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: Il contributo esplora il tema dell’attesa attraverso alcune sue variegate espressioni nei manoscritti del Medioevo e del Rinascimento, per sottolinearne gli aspetti legati alla cultura scritta, ai suoi protagonisti e ai suoi prodotti. Attraverso un piccolo excursus tra codici, documenti notarili, atti giudiziari e lettere manoscritte, fonti assai diverse fra loro per età, genere e caratteristiche, si ripercorre una gamma policroma e cangiante di scenari e manifestazioni di attesa, capaci di rivelare in controluce il mutare di percezioni e sensibilità, cultura e mentalità.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
Coordinated AMBER and MIDI observations of the Mira variable RR Aql
Creators: name: Karovicova, Iva
name: Wittkowski, Markus
name: Boboltz, David A.
name: Scholz, Michael
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have used near- and mid-infrared interferometry to investigate the pulsating atmosphere and the circumstellar environment of the Mira variable RR Aql. Observations were taken with the VLTI/AMBER (near infrared) and the VLTI/MIDI (mid infrared) instruments. We have obtained a total of 15 MIDI epochs between Apr 9, 2004 and Jul 28, 2007 covering 4 pulsation cycles and one AMBER epoch on Sep 9, 2006 at phase 2.82. This work is also part of an ongoing project of joint VLTI and VLBA observations to study the connection between stellar pulsation and the mass loss process. Here we present a comparison of the AMBER visibility data to a simple uniform disk model as well as to predictions by recent self-excited dynamic model atmospheres. The best fitting photospheric angular diameter of the model atmosphere at phase 2.82 is 9.9 +/- 2.4 mas.
description: 4 pages, 3 figures, to appear in Proc. of Cool Stars 15
L'attesa del re. Note per una lettura del Demetrio di Metastasio
Creators: name: Ferroni, Giovanni
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: Il contributo propone una lettura di Demetrio, il primo dramma scritto da Pietro Metastasio per la corte dell’imperatore Carlo VI d’Asburgo. A partire dalle testimonianze circa il successo dell’opera al debutto, se ne analizzano la struttura, i temi e i personaggi principali. Si mette così in evidenza l’importanza dell’attesa come oggetto della rappresentazione, come tecnica compositiva e come mezzo per orientare la ricezione del testo da parte del pubblico.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
Geometry reconstruction of fluorescence detectors revisited
Creators: name: Kuempel, D.
name: Kampert, K. -H.
name: Risse, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The experimental technique of fluorescence light observation is used in current and planned air shower experiments that aim at understanding the origin of ultra-high energy cosmic rays. In the fluorescence technique, the geometry of the shower is reconstructed from the correlation between arrival time and incident angle of the signals detected by the telescope. The calculation of the expected light arrival time used so far in shower reconstruction codes is based on several assumptions. Particularly, it is assumed that fluorescence photons are produced instantaneously during the passage of the shower front and that the fluorescence photons propagate on a straight line with vacuum speed of light towards the telescope. We investigate the validity of these assumptions, how to correct them, and the impact on reconstruction parameters when adopting realistic conditions. Depending on the relative orientation of the shower to the telescope, corrections can reach 100 ns in expected light arrival time, 0.1 deg in arrival direction and 5 g/cm^2 in depth of shower maximum. The findings are relevant also for the case of "hybrid" observations where the shower is registered simultaneously by fluorescence and surface detectors.
description: 17 pages, 8 figures; v2: minor modifications; accepted by Astropart. Phys
Declinazioni dell’attesa nell’Ossian in alcune spigolature montiane
Creators: name: Bianco, Francesca
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: Lo sperimentalismo linguistico del Cesarotti traduttore dell’Ossian segna un punto di svolta decisivo nel processo di cambiamento del gusto e nella creazione di una nuova langue poetica. Il tema dell’attesa, che gode di un’articolata declinazione all’interno dei poemetti, è un utile filtro per analizzare quanto l’officina dell’abate padovano abbia influito nella poesia successiva. Lo studio si propone di indagare questo fenomeno all’interno del percorso artistico di Vincenzo Monti, dai primi componimenti giovanili, come i Pensieri d’amore, fino al dittico napoleonico del Bardo della selva nera e della Spada di Federigo.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
“Attese” e strategie metrico-stilistiche nei recitativi di Metastasio
Creators: name: Roncen, Francesco
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: L’articolo analizza l’endecasillabo nei recitativi di Metastasio per approfondire la concezione dell’autore in merito al rapporto tra poesia e musica nel melodramma. La premessa è che tra la scrittura del libretto e della partitura vi è sempre un orizzonte di attese che può influenzare il lavoro del librettista e del musicista. Alcune affermazioni di Metastasio mostrano che egli era pienamente consapevole delle esigenze dei compositori. I dati ottenuti dall’analisi del primo atto di sei melodrammi, inoltre, sembrano suggerire che egli prendesse atto di tali esigenze per sviluppare strategie metriche in grado di produrre una sintesi ideale tra poesia e musica e una collaborazione virtuale con i compositori.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
democrazia ai tempi dei Ferragnez: l’attesa di una influencers politics dal like al voto
Creators: name: Bettinelli, Marianna
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: Nell’ultimo decennio, la presenza mediatica della giovane coppia Fedez e Chiara Ferragni è cresciuta a tal punto da farli diventare delle vere e proprie celebrità digitali. La loro esposizione pubblica sta contribuendo a creare un clima di attesa che li colloca nell’immaginario collettivo come leaders di influenza in grado di formulare interpretazioni su questioni politiche. Partendo dagli studi che prendono in considerazione la celebrity politics, questo testo analizza l’uso degli accordi retorici e delle emozioni da parte della coppia, prestando particolare attenzione sia al tipo di consenso instaurato tra follower e influencer sia ai potenziali scenari di utilizzo del consenso virtuale a scopo politico.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
High-pressure x-ray diffraction study on the structure and phase transitions of the defect-stannite ZnGa2Se4 and defect-chalcopyrite CdGa2S4
Creators: name: Errandonea, D.
name: Kumar, R. S.
name: Manjon, F. J.
name: Ursaki, V. V.
name: Tiginyanu, I. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: X-ray diffraction measurements on the sphalerite-derivatives ZnGa2Se4 and CdGa2S4 have been performed upon compression up to 23 GPa in a diamond-anvil cell. ZnGa2Se4 exhibits a defect tetragonal stannite-type structure (I-42m) up to 15.5 GPa and in the range from 15.5 GPa to 18.5 GPa the low-pressure phase coexists with a high-pressure phase, which remains stable up to 23 GPa. In CdGa2S4, we find the defect tetragonal chalcopyrite-type structure (I-4) is stable up to 17 GPa. Beyond this pressure a pressure-induced phase transition takes place. In both materials, the high-pressure phase has been characterized as a defect-cubic NaCl-type structure (Fm-3m). The occurrence of the pressure induced phase transitions is apparently related with an increase of the cation disorder on the semiconductors investigated. In addition, the results allow the evaluation of the axial compressibility and the determination of the equation of state for each compound. The obtained results are compared with those previously reported for isomorphic digallium sellenides. Finally, a systematic study of the pressure-induced phase transition in twenty-three different sphalerite-related ABX2 and AB2X4 compounds indicates that the transition pressure increases as the ratio of the cationic radii and anionic radii of the compounds increases.
description: 34 pages, 3 tables, 6 figurea
Development and validation of electrical-insulating Al2O3 coatings for high-temperature liquid PbLi applications
Creators: name: Saraswat, Abhishek
name: Sasmal, Chandrasekhar
name: Prajapati, Ashokkumar
name: Bhattacharyay, Rajendraprasad
name: Chaudhuri, Paritosh
name: Gedupudi, Sateesh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Electrical-insulating coatings are of great importance for liquid-metal breeder/coolant based systems relevant to fusion power plants. In specific to Pb-16Li eutectic, a candidate breeder material, such coatings are being actively investigated for their criticality in addressing various functionalities. For such applications, a candidate coating must be demonstrated for its compatibility with corrosive media, high operational temperatures and integrity of electrical-insulation over long durations without substantial degradation. At present, no relevant in-situ insulation resistance (IR) data is available for performance assessment of coated substrates within PbLi environment. To address this shortfall, an experimental study was performed at IPR towards application of high-purity alumina coatings on SS-316L substrates and further rigorous validation in static PbLi environment. The adopted coating process required a low-temperature heat treatment (< 430C) and could yield average coating thicknesses in the range of 100-500 micron. Coated samples were validated for their electrical insulation integrity in static PbLi over two test campaigns for continuous durations of over 700 h and 1360 h, including thermal cycling, at operational temperature between 300C-400C. Estimated volumetric electrical-resistivity remained of the order of 109-1011 ohm-cm without significant degradation. In-situ estimations of thermal derating factors establish excellent electrical-insulation characteristics after long term exposure to liquid PbLi. This paper presents details of utilized coating application methods, coating thickness estimations, liquid-metal test set-up, insulation performance and critical observations from SEM/EDX and XRD analysis on the tested samples.
Explicit constructions of infinite families of MSTD sets
Creators: name: Miller, Steven J.
name: Orosz, Brooke
name: Scheinerman, Daniel
Publisher: name: arXiv
Year: 2008
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11P99 (Primary), 11K99 (Secondary)

description: We explicitly construct infinite families of MSTD (more sums than differences) sets. There are enough of these sets to prove that there exists a constant C such that at least C / r^4 of the 2^r subsets of {1,...,r} are MSTD sets; thus our family is significantly denser than previous constructions (whose densities are at most f(r)/2^{r/2} for some polynomial f(r)). We conclude by generalizing our method to compare linear forms epsilon_1 A + ... + epsilon_n A with epsilon_i in {-1,1}.
description: Version 2: 14 pages, 1 figure. Includes extensions to ternary forms and a conjecture for general combinations of the form Sum_i epsilon_i A with epsilon_i in {-1,1} (would be a theorem if we could find a set to start the induction in general)
COVID-19 Working Paper: Single Commodity Export Dependence and the Impacts of COVID-19 in Sub-Saharan Africa
Creators: name: Gerval, Adam
name: Hansen, James
name: Gerval, Adam
name: Hansen, James
Publisher: name: Unknown
Year: 2022
Subjects: subject: International Relations/Trade
subject: Coronavirus
subject: COVID-19
subject: single-commodity dependence
subject: sub-Saharan Africa

description: This working paper illuminates the impact that volatility in international commodity prices has on U.S. agricultural product export volumes to sub-Saharan Africa (SSA). The current Coronavirus (COVID-19) crisis has created such a period of intense price volatility, offering a unique opportunity for modeling potential effects of a global shock on trade with these nations. By simulating the effects of declining oil prices in 2020 and subsequent years through a shock to gross domestic product (GDP) in oil-dependent nations—i.e., Angola and Nigeria—we can evaluate the impacts of COVID-19 on agricultural trade for key U.S. export commodities to SSA.
New and Old Tendencies in Labour Mediation among Early Twentieth-Century U.S. and European Composers
Creators: name: Piotrowska, Anna G.
Publisher: name: Austrian Journal of Historical Studies
Year: 2020

description: This paper presents strategies used by early twentieth-century composers in order to secure an income. In the wake of new economic realities, the Romantic legacy of the musician as creator was confronted by new expectations of his position within society. An analysis of written accounts by composers of various origins (British, German, French, Russian or American), including their artistic preferences and family backgrounds, reveals how they often resorted to jobs associated with musicianship such as conducting or teaching. In other cases, they willingly relied on patronage or actively sought new sources of employment offered by the nascent film industry and assorted foundations. Finally, composers also benefited from organized associations and leagues that campaigned for their professional recognition.
description: Austrian Journal of Historical Studies, Bd. 24 Nr. 1 (2013): Die Erzeugung des Berufs
A computational approach to the covert and overt deployment of spatial attention
Creators: name: Fix, Jérémy
name: Rougier, Nicolas P.
name: Alexandre, Frédéric
Publisher: name: arXiv
Year: 2008
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Popular computational models of visual attention tend to neglect the influence of saccadic eye movements whereas it has been shown that the primates perform on average three of them per seconds and that the neural substrate for the deployment of attention and the execution of an eye movement might considerably overlap. Here we propose a computational model in which the deployment of attention with or without a subsequent eye movement emerges from local, distributed and numerical computations.
Macroeconomic Variables and Profitability of Consumer Goods Manufacturing Firms in Nigeria
Creators: name: Seybold Report Journal
Publisher: name: Seybold Report Journal
Year: 2024
Subjects: Exchange rate, Earnings per share, Financial returns, Inflation rate, Interest rate, Profitability metric.

description: Abstract

Given the essential role of the manufacturing sector in promoting economic development within emerging economies such as Nigeria, it is imperative to investigate how macroeconomic policy indicators affect this sector. This study examines the impact of key macroeconomic variables on the profitability of consumer goods manufacturing firms in Nigeria. Utilizing an ex-post facto research design, the study analyzed secondary data sourced from the Central Bank of Nigeria (CBN) Statistical Bulletin and the financial reports of twelve listed consumer goods manufacturing firms over the period from 2006 to 2022. The data was subjected to analysis using a random effects panel regression model. The results reveal that inflation exerts a statistically significant positive effect on Return on Assets (ROA) (p = 0.0211 < 0.05) and Return on Equity (ROE) (p = 0.0368 < 0.05), while its effect on Return on Capital Employed (ROCE) (p = 0.0681 > 0.05) and Earnings per Share (EPS) (p = 0.7175 > 0.05) is not significant. Conversely, interest rates showed no significant impact on any of the profitability metrics. The study also found that fluctuations in the exchange rate had significant negative effects on ROA (p = 0.0000 < 0.05), ROE (p = 0.0160 < 0.05), and ROCE (p = 0.0015 < 0.05), with no significant effect on EPS (p = 0.0720 > 0.05). The findings suggest that while inflation and exchange rates significantly influence the manufacturing sector, these variables do not necessarily enhance financial returns for investors, as measured by EPS. Therefore, it is recommended to reduce lending costs to lower manufacturing expenses and enhance productivity, while the government should implement macroeconomic measures to mitigate detrimental inflationary effects.

 

Keywords:  Exchange rate, Earnings per share, Financial returns, Inflation rate, Interest rate, Profitability metric.
The Cultural, Didactic, and Physical Spaces of Mission Schools in the 19th Century
Creators: name: Jensz, Felicity
Publisher: name: Austrian Journal of Historical Studies
Year: 2013

description: Nineteenth century Protestant Mission schools were dynamic spaces, constantly reacting and adapting to hierarchic and hegemonic demands, whether of political, religious or societal nature. They were also ideological spaces, which through their form and function, articulated notions of the ‘proper’ place of non-Europeans in colonial society. This article examines the interconnected cultural, didactic and physical ‘spaces’ of mission schools in which a variety of competing ideologies and expectations were negotiated. The general conclusions demonstrate both the uniformity of missionary spaces, and simultaneously reveal spaces where, and times when, these generalities became disrupted.
description: Austrian Journal of Historical Studies, Bd. 24 Nr. 2 (2013): Missionsräume
CMB likelihood approximation by a Gaussianized Blackwell-Rao estimator
Creators: name: Rudjord, Ø.
name: Groeneboom, N. E.
name: Eriksen, H. K.
name: Huey, Greg
name: Górski, K. M.
name: Jewell, J. B.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We introduce a new CMB temperature likelihood approximation called the Gaussianized Blackwell-Rao (GBR) estimator. This estimator is derived by transforming the observed marginal power spectrum distributions obtained by the CMB Gibbs sampler into standard univariate Gaussians, and then approximate their joint transformed distribution by a multivariate Gaussian. The method is exact for full-sky coverage and uniform noise, and an excellent approximation for sky cuts and scanning patterns relevant for modern satellite experiments such as WMAP and Planck. A single evaluation of this estimator between l=2 and 200 takes ~0.2 CPU milliseconds, while for comparison, a single pixel space likelihood evaluation between l=2 and 30 for a map with ~2500 pixels requires ~20 seconds. We apply this tool to the 5-year WMAP temperature data, and re-estimate the angular temperature power spectrum, $C_{\ell}$, and likelihood, L(C_l), for l<=200, and derive new cosmological parameters for the standard six-parameter LambdaCDM model. Our spectrum is in excellent agreement with the official WMAP spectrum, but we find slight differences in the derived cosmological parameters. Most importantly, the spectral index of scalar perturbations is n_s=0.973 +/- 0.014, 1.9 sigma away from unity and 0.6 sigma higher than the official WMAP result, n_s = 0.965 +/- 0.014. This suggests that an exact likelihood treatment is required to higher l's than previously believed, reinforcing and extending our conclusions from the 3-year WMAP analysis. In that case, we found that the sub-optimal likelihood approximation adopted between l=12 and 30 by the WMAP team biased n_s low by 0.4 sigma, while here we find that the same approximation between l=30 and 200 introduces a bias of 0.6 sigma in n_s.
description: 10 pages, 7 figures, submitted to ApJ
Global History in a National Context: The Case of Germany
Creators: name: Osterhammel, Jürgen
Publisher: name: Austrian Journal of Historical Studies
Year: 2009

description: The article distinguishes between various forms of macro-history. It analyses their respective representation in German historical scholarship during the twentieth century, with special emphasis on recent decades. Reasons for the prevalence of certain historiographical traditions over others and for the comparative weakness of world history and global history in contemporary Germany are being discussed. The article concludes with a brief sketch of several ongoing debates.
description: Austrian Journal of Historical Studies, Bd. 20 Nr. 2 (2009): Global History
„Das ist wie ein künstlerischer Arbeitsprozess“
Creators: name: Wimmer, Mario
name: Raulff, Ulrich
Publisher: name: Österreichische Zeitschrift für Geschichtswissenschaften
Year: 2009

description: Österreichische Zeitschrift für Geschichtswissenschaften, Bd. 20 Nr. 1 (2009): Fortschritt
Quantum evolution kernel : Machine learning on graphs with programmable arrays of qubits
Creators: name: Henry, Louis-Paul
name: Thabet, Slimane
name: Dalyac, Constantin
name: Henriet, Loïc
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The rapid development of reliable Quantum Processing Units (QPU) opens up novel computational opportunities for machine learning. Here, we introduce a procedure for measuring the similarity between graph-structured data, based on the time-evolution of a quantum system. By encoding the topology of the input graph in the Hamiltonian of the system, the evolution produces measurement samples that retain key features of the data. We study analytically the procedure and illustrate its versatility in providing links to standard classical approaches. We then show numerically that this scheme performs well compared to standard graph kernels on typical benchmark datasets. Finally, we study the possibility of a concrete implementation on a realistic neutral-atom quantum processor.
Electron-hole scattering limited transport of Dirac fermions in a topological insulator
Creators: name: Müller, Valentin L.
name: Yan, Yuan
name: Kashuba, Oleksiy
name: Trauzettel, Björn
name: Abdelghany, Mohamed
name: Kleinlein, Johannes
name: Beugeling, Wouter
name: Buhmann, Hartmut
name: Molenkamp, Laurens W.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We experimentally investigate the effect of electron temperature on transport in the two-dimensional Dirac surface states of the three-dimensional topological insulator HgTe. We find that around the minimal conductivity point, where both electrons and holes are present, heating the carriers with a DC current results in a non-monotonic differential resistance of narrow channels. We show that the observed initial increase in resistance can be attributed to electron-hole scattering, while the decrease follows naturally from the change in Fermi energy of the charge carriers. Both effects are governed dominantly by a van Hove singularity in the bulk valence band. The results demonstrate the importance of interband electron-hole scattering in the transport properties of topological insulators.
Qualitätssicherung von Online-Kursen in E-Learning Portalen
Creators: name: Iske, Stefan
name: Meder, Norbert
Publisher: name: Medienimpulse
Year: 2010

description: Dieser Artikel fokussiert den Bereich des Qualitätsmanagements im e-Learning am Beispiel der Qualitätssicherung von Online-Kursen in einem E-Learning-Portal. Dargestellt wird ein Work-Flow spezifischer Qualitätsmanagement-Prozesse: (1) allgemeine Unterstützung der Autoren von Online-Kursen, (2) Evaluation erstellter Online-Kurse, (3) Feedback der Lernenden (Kursteilnehmer) an den Kurs-Autor, (4) Feedback der Lernenden an das Qualitätssicherungs-Team (5) Feedback der Kurs-Autoren an das Qualitätssicherungs-Team, sowie (6) die zusammenfassende Evaluation des Lernenden- und Experten-Feedback durch das Qualitätssicherungs-Team. Dieser Work-Flow wurde empirisch getestet und in den europäischen E-Learning-Marktplatz "Columbus-Portal" implementiert, welcher im Rahmen des von der Europäischen Kommission (eTEN-Programm) finanzierten Projektes " Electronic Learning and Assistan­ce Network" (ELAN) entwickelt wurde.
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Kairós in science blogging: immediacy, self-expression and audience engagement
Creators: name: Freddi, Maria
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: Il presente contributo indaga il concetto retorico di «kairós» quale fattore decisivo del successo argomentativo della comunicazione scientifica online per evidenziarne la forma linguistica che assume nei blog di scienza, un genere di discorso sempre più usato da scienziati e gruppi di ricerca internazionali per coinvolgere il pubblico di esperti e non-esperti nell’impresa scientifica moderna. L’approccio è insieme retorico e linguistico, attingendo in particolare dagli studi di Carolyn Miller e colleghi sui generi della divulgazione scientifica e fondando l’analisi linguistica su osservazioni di frequenza in un corpus di blogs mantenuti da singoli scienziati di aree diverse.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
paziente impaziente. Le strutture retoriche dell’attesa nel dialogo medico-paziente
Creators: name: Gambarelli, Gaia
name: Passaro, Elvira
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: L’anamnesi, la ricerca di un’identificazione patologica o di un piano terapeutico poggiano le loro fondamenta sull’attesa. In che modo l’attesa viene nutrita dal punto di vista retoricoargomentativo nel dialogo di cura? Lo strumento linguistico è utile a identificare consapevolmente gli orizzonti d’attesa e a interpretare la narrazione della sofferenza. La precisione sartoriale della cura assume un duplice significato: di adattamento/modellamento sul paziente e di struttura/morfologia di attese in divenire. La metodologia del lavoro consiste nel portare alla luce riflessioni teoriche generalizzabili su aspetti retorico-argomentativi distintivi del dialogo medico-paziente applicando il Trattato dell’Argomentazione di Perelman all’analisi di exempla di consultazioni.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
Charge transport in ballistic multiprobe graphene structures
Creators: name: Laakso, M. A.
name: Heikkilä, T. T.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the the transport properties of multiterminal ballistic graphene samples, concentrating on the conductance matrix, fluctuations and cross-correlations. Far away from Dirac point, the current is carried mostly by propagating modes and the results can be explained with the conventional semiclassical picture familiar from ray optics, where electrons propagate along a single direction before scattering or reaching the terminals. However, close to the Dirac point the transport is due to evanescent modes which do not have to follow a rectilinear path. As we show in this Letter, this property of the evanescent modes influences the conductance matrix. However, at best it can be observed by measuring the cross correlations in an exchange Hanbury Brown-Twiss experiment.
description: 5 pages, 5 figures
Jugendliche Medienwelten - Ergebnisse der 1. Jugend-Medien-Studie des BIMEZ
Creators: name: (BiMeZ), BildungsMedienZentrum
Publisher: name: Medienimpulse
Year: 2010

description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Ergodic Numerical Approximation to Periodic Measures of Stochastic Differential Equations
Creators: name: Feng, Chunrong
name: Liu, Yu
name: Zhao, Huaizhong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 37H99, 60H10, 60H35

description: In this paper, we consider numerical approximation to periodic measure of a time periodic stochastic differential equations (SDEs) under weakly dissipative condition. For this we first study the existence of the periodic measure $ρ_t$ and the large time behaviour of $\mathcal{U}(t+s,s,x) := \mathbb{E}ϕ(X_{t}^{s,x})-\intϕdρ_t,$ where $X_t^{s,x}$ is the solution of the SDEs and $ϕ$ is a test function being smooth and of polynomial growth at infinity. We prove $\mathcal{U}$ and all its spatial derivatives decay to 0 with exponential rate on time $t$ in the sense of average on initial time $s$. We also prove the existence and the geometric ergodicity of the periodic measure of the discretized semi-flow from the Euler-Maruyama scheme and moment estimate of any order when the time step is sufficiently small (uniform for all orders). We thereafter obtain that the weak error for the numerical scheme of infinite horizon is of the order $1$ in terms of the time step. We prove that the choice of step size can be uniform for all test functions $ϕ$. Subsequently we are able to estimate the average periodic measure with ergodic numerical schemes.
Wave Analysis and Homogenization of Spatiotemporally Modulated Wire Medium
Creators: name: Kreiczer, Michael
name: Hadad, Yakir
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this paper we develop homogenization theory for spatiotemporally modulated wire medium. We first solve for the modal waves that are supported by this composite medium, we show peculiar properties such as extraordinary waves that propagate at frequencies below the cut-off frequency of the corresponding stationary medium. We explain how these unique solutions give rise to an extreme Fresnel drag that exists already with weak and slow spatiotemporal modulation. Next, we turn to derive the effective material permittivity that corresponds to each of the first few supported modes, and write the average fields and Poynting's vector. Nonlocality, nonreciprocity, and anisotropy due to the spatiotemporal modulation direction, are three inherent properties of this medium, and are clearly seen in the effective material parameters. As a figure of merit, we also derive the effective permittivity of a plasma medium with spatiotemporally modulated plasma frequency. This comparison is interesting since the plasma medium can be considered as the effective medium that is obtained by a stationary wire medium. We validate that homogenization and spatiotemporal variation are not necessarily interchangeable operations. And indeed, in certain parameter regimes the homogenization should be performed directly on spatiotemporally modulated composite medium, rather than first homogenize the stationary medium and then phenomenologically introduce the effect of the space-time modulation.
description: 15 pages, 9 figures
razionalizzazione della speranza
Creators: name: Albarello, Dario
Publisher: name: DNA – Di Nulla Academia
Year: 2021

description: La razionalizzazione dell’attesa, intesa come aspettativa o ‘speranza’ riguardo ad un futuro possibile, è stata declinata non in funzione dell’eliminazione dell’incertezza sul futuro (che viene assunta come caratteristica immanente ed ineliminabile del mondo) ma come volta a definire il comportamento razionale di un soggetto deliberante a fronte dei possibili esiti delle sue azioni. Un comportamento che viene inteso come ‘liberamente’ razionale, non per le propensioni del soggetto responsabile della deliberazione, quanto piuttosto per la coerenza delle argomentazioni che la supportano. Queste argomentazioni non garantiscono il successo dell’azione scelta dal soggetto deliberante, quanto piuttosto la rendono accettabile da parte della comunità di riferimento alla luce delle sue possibili conseguenze.
description: DNA – Di Nulla Academia, Vol. 2 No. 1 (2021): The direction of the wait
Leveraging CAM Algorithms for Explaining Medical Semantic Segmentation
Creators: name: Rheude, Tillmann
name: Wirtz, Andreas
name: Kuijper, Arjan
name: Wesarg, Stefan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Convolutional neural networks (CNNs) achieve prevailing results in segmentation tasks nowadays and represent the state-of-the-art for image-based analysis. However, the understanding of the accurate decision-making process of a CNN is rather unknown. The research area of explainable artificial intelligence (xAI) primarily revolves around understanding and interpreting this black-box behavior. One way of interpreting a CNN is the use of class activation maps (CAMs) that represent heatmaps to indicate the importance of image areas for the prediction of the CNN. For classification tasks, a variety of CAM algorithms exist. But for segmentation tasks, only one CAM algorithm for the interpretation of the output of a CNN exist. We propose a transfer between existing classification- and segmentation-based methods for more detailed, explainable, and consistent results which show salient pixels in semantic segmentation tasks. The resulting Seg-HiRes-Grad CAM is an extension of the segmentation-based Seg-Grad CAM with the transfer to the classification-based HiRes CAM. Our method improves the previously-mentioned existing segmentation-based method by adjusting it to recently published classification-based methods. Especially for medical image segmentation, this transfer solves existing explainability disadvantages.
description: Accepted for publication at the Journal of Machine Learning for Biomedical Imaging (MELBA) https://melba-journal.org/2024:023
„Open Educational Resources“ (OER) – Ein medienpädagogischer Bildungsstandard im Web-2.0-Zeitalter? Zur diskursiven Verortung eines emergierenden Paradigmas
Creators: name: Filk, Christian
name: Bergamin, Per
Publisher: name: Medienimpulse
Year: 2010

description: Open Educational Resources (OER) sind per definitionem Lernmaterialien, die für den Gebrauch, die Überarbeitung und Weitergabe frei verfügbar sind. Der Beitrag geht der Frage nach, ob gegenwärtige Entwicklungen in der Domäne der Open Educational Resources neue Modelle für Lernmaterialien etablieren und wie OER als richtungweisender medienpädagogischer Bildungsstandard reüssieren könnten? Die Autoren analysieren drängende Probleme und wichtige Dispositionen der Konzeption, Distribution und Evaluation von Open Educational Resources. Auf dieser Grundlage vertiefen sie die Diskussion, indem sie die Nutzung, Technik, Ökonomie und Didaktik von OER problembezogen herausarbeiten. Die Autoren gelangen zu der Schluss, dass die Debatte um Medienpädagogik und Bildungsstandards nicht nur eine fundamentale Neuorientierung erfahren könnte, sondern zudem einen nachhaltigen Paradigmenwechsel in der Bildungspolitik und der Erziehungswissenschaft auslösen könnte – vom individuellen Aneignen von Wissen zum kollaborativen Erzeugen von Wissen.
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Applications of Automata and Graphs: Labeling Operators in Hilbert Space II
Creators: name: Cho, Ilwoo
name: Jorgensen, Palle E. T.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Operator Algebras (math.OA)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 05C62; 05C90; 17A50; 18B40; 46K10; 47A67; 47A99; 47B99

description: We introduced a family of infinite graphs directly associated with a class of von Neumann automaton model A_{G}. These are finite state models used in symbolic dynamics: stimuli models and in control theory. In the context of groupoid von Neumann algebras, and an associated fractal group, we prove a classification theorem for representations of automata.
description: 61 pages
EU Kids Online – Der sichere Umgang mit dem Internet. Österreich im europäischen Vergleich
Creators: name: Paus-Hasebrink, Ingrid
name: Dürager, Andrea
Publisher: name: Medienimpulse
Year: 2010

description: Die Ergebnisse des dreijährigen europäischen Forschungsprojektes „EU Kids Online I“ zu Erfahrungen von Kindern und Jugendlichen mit dem Internet in Europa zeigen, dass die Forschungslage zu dieser Thematik in Österreich – aber auch in vielen anderen Ländern – als defizitär bezeichnet werden muss. Zudem zählt Österreich bei mittlerer Nutzungshäufigkeit des Internets zu den Ländern mit immerhin mittlerem Online-Risiko. Österreichische Eltern scheinen sich der mit der Internetnutzung ihrer Kinder verbundenen Gefahren noch recht wenig bewusst zu sein. Im Nachfolgeprojekt "EU Kids Online II" steht nun der Bereich der Online-Risiken im Mittelpunkt einer europaweiten Befragung.
description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
COVID-19 Working Paper: The Impact of COVID-19 Pandemic on Food-Away-From-Home Spending
Creators: name: Marchesi, Keenan
name: McLaughlin, Patrick W
name: Marchesi, Keenan
name: McLaughlin, Patrick W
Publisher: name: Unknown
Year: 2022
Subjects: subject: Consumer/Household Economics
subject: COVID-19
subject: food away from home
subject: FAFH
subject: spending

description: This paper summarizes national changes in the frequency and dollar amount of U.S. consumers’ food-away-from-home (FAFH) purchases during the COVID-19 pandemic. The analysis draws on frequently updated proprietary data sources to measure national FAFH trends in average monthly spending and the weekly number of store transactions. Both spending and transactions at restaurants fell substantially following the onset of the pandemic and remained below pre-pandemic levels more than 1 year later. Differences in the decline in spending and transactions across restaurant types and mealtimes are notable. Although restaurant restrictions loosened across the country in the first half of 2021, visits and spending have been slow to recover to their pre-pandemic levels.
Aufsuchende Audioarbeit am Beispiel des Projekts „Stuwer City“ - Ein Erfahrungsbericht
Creators: name: Art, Gecko -
Publisher: name: Medienimpulse
Year: 2010

description: Medienimpulse, Bd. 47 Nr. 1 (2009): 1/2009 - Standards in der Medienbildung
Dispersive Approach to Chiral Perturbation Theory
Creators: name: Zdrahal, M.
name: Novotny, J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We generalise the reconstruction theorem of Stern, Sazdjian, and Fuchs based on the dispersion relations to the case of the (2 -> 2) scattering of all the pseudoscalar octet mesons (pi, K, eta). We formulate it in a general way and include also a discussion of the assumptions of the theorem. It is used to obtain the amplitudes of all such processes in the isospin limit to the one-loop order (and can be straightforwardly extended to two loops) independently on the particular power-counting scheme of the chiral perturbation theory in question. The results in this general form are presented.
description: 25 pages, 1 figure; added one appendix and correction of typos
Unsupervised Learning for Cuboid Shape Abstraction via Joint Segmentation from Point Clouds
Creators: name: Yang, Kaizhi
name: Chen, Xuejin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: Representing complex 3D objects as simple geometric primitives, known as shape abstraction, is important for geometric modeling, structural analysis, and shape synthesis. In this paper, we propose an unsupervised shape abstraction method to map a point cloud into a compact cuboid representation. We jointly predict cuboid allocation as part segmentation and cuboid shapes and enforce the consistency between the segmentation and shape abstraction for self-learning. For the cuboid abstraction task, we transform the input point cloud into a set of parametric cuboids using a variational auto-encoder network. The segmentation network allocates each point into a cuboid considering the point-cuboid affinity. Without manual annotations of parts in point clouds, we design four novel losses to jointly supervise the two branches in terms of geometric similarity and cuboid compactness. We evaluate our method on multiple shape collections and demonstrate its superiority over existing shape abstraction methods. Moreover, based on our network architecture and learned representations, our approach supports various applications including structured shape generation, shape interpolation, and structural shape clustering.
description: 11 pages
Laser Induced Selective Alignment of Water Spin Isomers
Creators: name: Gershnabel, E.
name: Averbukh, I. Sh.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We consider laser alignment of ortho and para spin isomers of water molecules by using strong and short off-resonance laser pulses. A single pulse is found to create a distinct transient alignment and antialignment of the isomeric species. We suggest selective alignment of one isomeric species (leaving the other species randomly aligned) by a pair of two laser pulses.
description: 6 pages, 4 figures, 3 tables
Quantum Graph Convolutional Neural Networks
Creators: name: Zheng, Jin
name: Gao, Qing
name: Lv, Yanxuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: At present, there are a large number of quantum neural network models to deal with Euclidean spatial data, while little research have been conducted on non-Euclidean spatial data. In this paper, we propose a novel quantum graph convolutional neural network (QGCN) model based on quantum parametric circuits and utilize the computing power of quantum systems to accomplish graph classification tasks in traditional machine learning. The proposed QGCN model has a similar architecture as the classical graph convolutional neural networks, which can illustrate the topology of the graph type data and efficiently learn the hidden layer representation of node features as well. Numerical simulation results on a graph dataset demonstrate that the proposed model can be effectively trained and has good performance in graph level classification tasks.
Inverse kinetic theory approach to turbulence theory
Creators: name: Tessarotto, M.
name: Ellero, M.
name: Nicolini, P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: A fundamental aspect of turbulence theory is related to the identification of realizable phase-space statistical descriptions able to reproduce in some suitable sense the stochastic fluid equations of a turbulent fluid. In particular, a major open issue is whether a purely Markovian statistical description of hydrodynamic turbulence actually can be achieved. Based on the formulation of a \textit{deterministic inverse kinetic theory} (IKT) for the 3D incompressible Navier-Stokes equations, here we claim that such a \textit{Markovian statistical description actually exists}. The approach, which involves the introduction of the \textit{local velocity probability density} for the fluid (local pdf) - rather than the velocity-difference pdf adopted in customary approaches to homogeneous turbulence - relies exclusively on first principles. These include - in particular - the exact validity of the stochastic Navier-Stokes equations, the principle of entropy maximization and a constant H-theorem for the Shannon statistical entropy. As a result, the new approach affords an exact equivalence between Lagrangian and Eulerian formulations which permit local pdf's which are generally non-Maxwellian (i.e., non-Gaussian). The theory developed is quite general and applies in principle even to turbulence regimes which are non-stationary and non-uniform in a statistical sense.
description: Contributed paper at RGD26 (Kyoto, Japan, July 2008)
Time variation of fundamental couplings and dynamical dark energy
Creators: name: Dent, Thomas
name: Stern, Steffen
name: Wetterich, Christof
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Scalar field dynamics may give rise to a nonzero cosmological variation of fundamental constants. Within different scenarios based on the unification of gauge couplings, the various claimed observations and bounds may be combined in order to trace or restrict the time history of the couplings and masses. If the scalar field is responsible for a dynamical dark energy or quintessence, cosmological information becomes available for its time evolution. Combining this information with the time variation of couplings, one can determine the interaction strength between the scalar and atoms, which may be observed by tests of the Weak Equivalence Principle. We compute bounds on the present rate of coupling variation from experiments testing the differential accelerations for bodies with equal mass and different composition and compare the sensitivity of various methods. In particular, we discuss two specific models of scalar evolution: crossover quintessence and growing neutrino models.
description: 26 pages, 2 figures; minor typos & added references, to be published in JCAP