cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
How long before the end of inflation were observable perturbations produced?
Creators: name: Liddle, Andrew R
name: Leach, Samuel M
Publisher: name: arXiv
Year: 2003
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We reconsider the issue of the number of e-foldings before the end of inflation at which observable perturbations were generated. We determine a plausible upper limit on that number for the standard cosmology which is around 60, with the expectation that the actual value will be up to 10 below this. We also note a special property of the $λϕ^4$ model which reduces the uncertainties in that case and favours a higher value, giving a fairly definite prediction of 64 e-foldings for that model. We note an extreme (and highly implausible) situation where the number of e-foldings can be even higher, possibly up to 100, and discuss the shortcomings of quantifying inflation by e-foldings rather than by the change in $aH$. Finally, we discuss the impact of non-standard evolution between the end of inflation and the present, showing that again the expected number of e-foldings can be modified, and in some cases significantly increased.
description: 7 pages RevTeX4 file with one figure incorporated. Minor updates to match version accepted by Physical Review D
Type Ia Supernova Explosions from Hybrid Carbon-Oxygen-Neon White Dwarf Progenitors That Have Mixed During Cooling
Creators: name: Augustine, Carlyn N.
name: Willcox, Donald E.
name: Brooks, Jared
name: Townsley, Dean M.
name: Calder, Alan C.
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The creation of "hybrid" white dwarfs, made of a C-O core within a O-Ne shell has been proposed, and studies indicate that ignition in the C-rich central region makes these viable progenitors for thermonuclear (type Ia) supernovae. Recent work found that the C-O core is mixed with the surrounding O-Ne as the white dwarf cools prior to accretion, which results in lower central C fractions in the massive progenitor than previously assumed. To further investigate the efficacy of hybrid white dwarfs as progenitors of thermonuclear supernovae, we performed simulations of thermonuclear supernovae from a new series of hybrid progenitors that include the effects of mixing during cooling. The progenitor white dwarf model was constructed with the one-dimensional stellar evolution code MESA and represented a star evolved through the phase of unstable interior mixing followed by accretion until it reached conditions for the ignition of carbon burning. This MESA model was then mapped to a two-dimensional initial condition for explosions simulated with FLASH. For comparison, similar simulations were performed for a traditional C-O progenitor white dwarf. By comparing the yields of the explosions, we find that, as with earlier studies, the lower C abundance in the hybrid progenitor compared to the traditional C-O progenitor leads to a lower average yield of 56Ni. Although the unmixed hybrid WD showed a similar decrement also in total iron group yield, the mixed case does not and produces a smaller fraction of iron group elements in the form of 56Ni. We attribute this to the higher central density required for ignition and the location, center or off-center, of deflagration ignition.
description: 19 pages, 7 figures, accepted by the Astrophysical Journal
Hyper-symplectic structures on integrable systems
Creators: name: Bartocci, C.
name: Mencattini, I.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C26; 53D99; 37J35

description: We prove that an integrable system over a symplectic manifold, whose symplectic form is covariantly constant w.r.t. the Gauss-Manin connection, carries a natural hyper-symplectic structure. Moreover, a special Kaehler structure is induced on the base manifold.
description: LaTeX file, 7 pages; to be published in Journal of Geometry and Physics
Machine learning for a non-modulated pyramid wavefront sensor
Creators: name: Rossi, Fabio
name: Agapito, Guido
Publisher: name: Proceedings of AO4ELT7 conference 2023 - Editors: Thierry Fusco and Benoit Neichel
Year: 2023
Subjects: PYRAMID WAVEFRONT SENSOR
SIMULATION
MACHINE LEARNING
NEURAL NETWORK
RECONSTRUCTOR

description: Most of the future single conjugate adaptive optics systems for the extremely large telescopes will use pyramid wavefront sensors and will face the challenge of measuring and controlling the turbulence and the differential piston. We know that this kind of sensor has a non-linear response that cannot be fully exploited by linear reconstruction. In particular this is valid for a non-modulated pyramid wavefront sensor that has some advantage in terms of sensibility, but it is strongly affected by non-linearities. For this reason, we explore the possibility of using a reconstruction method based on neural networks. Our goal is to replace the usual linear reconstructor which is normally obtained as the pseudo-inverse of the interaction matrix, with a non-linear one which has the form of a deep neural network. The network architecture and its training strategy are tailored for our problem, while the data used for the network training and its performance evaluation were produced in end-to-end simulation. We will show the promising results obtained for the open loop reconstruction and the preliminary analysis performed in the perspective to apply this method in closed loop operations.
title: Price Stickiness, Inflation, and Output Dynamics: A Cross-Country Analysis
Creators: name: Khan, Hashmat
Publisher: name: Bank of Canada
Year: 2000

description: The sticky-price model of aggregate fluctuations implies that countries with high trend inflation rates should exhibit less-persistent output fluctuations than countries with low trend inflation. I conduct a cross-country analysis of output persistence and inflation that takes into account the within-country time variation in trend inflation. My results do not support the implication. The results suggest that further research is needed before models based on nominal price stickiness can offer a complete microfoundation for persistent effects of aggregate demand shocks.
description: D'après l'explication que le modèle à prix rigides fournit du cycle économique, les fluctuations de la production devraient être moins persistantes dans les économies où le taux de l'inflation tendancielle est élevé que dans celles où il est bas. L'auteur analyse la persistance de la production et l'inflation dans divers pays tout en tenant compte des variations temporelles que l'inflation tendancielle affiche dans chacun d'eux. Ses résultats ne confirment pas la validité du modèle examiné. De nouvelles recherches semblent nécessaires pour que des modèles reposant sur l'hypothèse de rigidité des prix nominaux parviennent à expliquer entièrement au niveau microéconomique la persistance des effets des chocs de demande globale.
Enhanced stability, bistability, and exceptional points in saturable active photonic couplers
Creators: name: Zhiyenbayev, Yertay
name: Kominis, Yannis
name: Valagiannopoulos, Constantinos
name: Kovanis, Vassilios
name: Bountis, Anastasios
Publisher: name: arXiv
Year: 2019
Subjects: subject: Optics (physics.optics)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: A generic photonic coupler with active and lossy parts, gain saturation and asymmetric characteristics is examined. Saturable activity is shown to be able to enhance the overall stability of the steady states, prevent evolution to undesirable unbounded modes and allow for bistable operation in specific regions of parametric space. Both stability and bistability are studied in the phase space of the system, where the basins of attraction of each state are identified, providing an accurate description of the dependence of the electric fields on the initial conditions. Continuous families of exceptional points are detected via suitable regulation of the coupling and asymmetry features of the configuration. In this way, a complete description of the nonlinear dynamics landscape is provided, which should be crucial for multiple application-driven designs incorporating such a ubiquitous optical component.
description: 21 pages, 9 figures
The Full Mottness
Creators: name: Stanescu, Tudor D.
name: Phillips, Philip
Publisher: name: arXiv
Year: 2003
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Though most fermionic Mott insulators order at low temperatures, ordering is ancillary to their insulating behaviour. Our emphasis here is on disentangling ordering from the intrinsic strongly correlated physics of a doped half-filled band. To this end, we focus on the 2D Hubbard model. Because the charge gap arises from on-site correlations, we implement a non-perturbative approach which incorporates local physics. Crucial to this method is a self-consistent two-site dynamical cluster expansion which builds in the nearest-neighbour energy scale, $J$. At half-filling, we find that the spectral function possesses a gap of order $U$ and is devoid of any coherent quasi-particle peaks. In the doped case, we find that the Fermi surface exceeds the Luttinger volume. Additionally in the underdoped regime, we find that a pseudogap opens in the single particle density of states.The pseudogap closes above optimal doping and hence our proposal is not inconsistent with that of Loram. In analogy with the Mott gap and antiferromagnetism, we propose that ordering may also accompany the formation of a pseudogap. We suggest a current pattern within a 1-band model that preserves translational but breaks time-reversal symmetry along the canonical x and y axes but not along $x=\pm y$ that is consistent with the experimental observations. Finally, we show that the Hall coefficient in a doped Mott insulator must change sign at a doping level $x<1/3$. The sign change is tied to a termination of strong correlation physics in the doped Mott state.
description: 37 pages, 21 .eps files and 5 appendices. Revised version to appear in PRB
Analyse des systèmes de commercialisation de la corète potagère (Corchorus olitorius L.) produite à Agbédranfo au Sud-Ouest du Bénin (Département du Couffo)
Creators: name: Komlan, C.
name: Adegbola, Patrice Ygue
name: Adegbidi, Anselme
name: Adetonah, Sounkoura
name: Guy-Apollinaire, Mensah
name: Komlan, C.
name: Adegbola, Patrice Ygue
name: Adegbidi, Anselme
name: Adetonah, Sounkoura
name: Guy-Apollinaire, Mensah
Publisher: name: Unknown
Year: 2013
Subjects: subject: Teaching/Communication/Extension/Profession
subject: Corchorus olitorius L
subject: Agbédranfo
subject: Commercialisation
subject: Rentabilité
subject: paradigme SCP
subject: marge

description: La présente étude s’intéresse à l’analyse du fonctionnement des systèmes de commercialisation de la corète (Corchorus olitorius) produite à Agbédranfo (Dogbo). L’approche méthodologique utilisée s’est fondée sur le paradigme Structure-Conduite-Performance (SCP). L’échantillonnage a été fait par catégorie d’acteurs et a été raisonné. Au total, 60 producteurs, 28 détaillantes et 4 grossistes ont été enquêtés. Les résultats obtenus ont permis d’identifier deux systèmes de commercialisation de la corète en fonction des périodes de vente de la corète produite à Agbédranfo et des lieux de production : système de commercialisation de la corète des bas-fonds et système de commercialisation de la corète des terres de plateau. L’analyse des marges a montré que la vente de la corète produite à Agbédranfo assure des marges nettes relatives de 3,24 pour les producteurs, 9,67 pour les détaillantes et 8,37 pour les grossistes contrairement aux marges nettes relatives faibles de ces acteurs dans le système de commercialisation de la corète des terres de plateau. En outre, un coefficient de Gini de 0,34109 indique une répartition inégale des marges nettes obtenues au niveau du système de commercialisation de la corète des bas-fonds. Une concertation entre les acteurs de la commercialisation eux-mêmes, les agents du CeCPA, les ONGs, et le pouvoir publique est alors souhaitée.
Anomalous ultraviolet line flux ratios in the cataclysmic variables 1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg observed with HST/STIS
Creators: name: Gänsicke, Boris T.
name: Szkody, Paula
name: de Martino, Domitilla
name: Beuermann, Klaus
name: Long, Knox S.
name: Sion, Edward M.
name: Knigge, Christian
name: Marsh, Tom
name: Hubeny, Ivan
Publisher: name: arXiv
Year: 2003
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Brief HST/STIS spectroscopic snapshot exposures of the cataclysmic variables 1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg reveal very large NV/CIV line flux ratios, similar to those observed in AE Aqr. Such anomalous line flux ratios have so far been observed in 10 systems, and presumably reflect a different composition of the accreted material compared to the majority of cataclysmic variables. We discuss the properties of this small sample in the context of the recent proposal by Schenker et al. (2002) that a significant fraction of the present-day population of cataclysmic variables may have passed through a phase of thermal time-scale mass transfer.
description: 6 pages AAS-Latex, uses emulatapj.sty, 3 figures, accepted for publication in ApJ
Predicting aggregate food consumption for a specific geographic area: an application to southeast Minnesota
Creators: name: Wang, Yuki
name: Wang, Yuki
Publisher: name: Unknown
Year: 2011
Subjects: subject: Consumer/Household Economics
subject: Food Consumption/Nutrition/Food Safety
subject: CEX
subject: ACS
subject: foodshed

description: This thesis develops a framework for estimating food expenditures for a variety of U.S. communities, including regions, states counties and metropolitan areas. The framework is then illustrated by providing estimates of household expenditures for 19 food categories at the national level, in the Twin Cities metropolitan area and in the Southeastern Minnesota area. First household characteristics are related to food expenditures using Consumer Expenditure Survey Data (CEX); then expenditures are aggregated at the community level by applying household demographic profiles from American Community Survey data to the estimations from Consumer Expenditure Survey data. This research is distinctive because (1) it suggests a general and universal model for forecasting food expenditure patterns at almost any regional level; and (2) it provides a good estimation of food expenditure to match with current foodshed analysis. The regression results present a comprehensive relationship between demographic factors and consumer expenditures on 19 food categories. Findings also show that household purchasing patterns are significantly different across regions and that it is not accurate to use average CEX results for the nation to estimate aggregate expenditure by households in a particular locale.
Beyond Squeezing à la Virasoro Algebra
Creators: name: Katagiri, So
name: Sugamoto, Akio
name: Yamaguchi, Koichiro
name: Yumibayashi, Tsukasa
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The generalization of squeezing is realized in terms of the Virasoro algebra. The higher-order squeezing can be introduced through the higher-order time-dependent potential, in which the standard squeezing operator is generalized to higher-order Virasoro operators. We give a formula that describes the number of particles generated by the higher-order squeezing when a parameter specifying the degree of squeezing is small. The formula (18) shows that the higher the order of squeezing becomes the larger the number of generated particles grows.
description: 16 pages, 2 figures
Risk, Insurance and Wages in General Equilibrium
Creators: name: Mobarak, Ahmed Musfiq
name: Rosenzweig, Mark
name: Mobarak, Ahmed Musfiq
name: Rosenzweig, Mark
Publisher: name: Unknown
Year: 2013
Subjects: subject: Agricultural and Food Policy
subject: International Development
subject: Marketing
subject: FOS: Economics and business
subject: Risk and Uncertainty
subject: index insurance
subject: agricultural wages
subject: general equilibrium effects

description: We estimate the general-equilibrium labor market effects of a large-scale randomized intervention in which we designed and marketed a rainfall index insurance product across three states in India. Marketing agricultural insurance to both cultivators and to agricultural wage laborers allows us to test a general-equilibrium model of wage determination in settings where households supplying labor and households hiring labor face weather risk. Consistent with theoretical predictions, we find that both labor demand and equilibrium wages become more rainfall sensitive when cultivators are offered rainfall insurance, because insurance induces cultivators to switch to riskier, higher-yield production methods. The same insurance contract offered to agricultural laborers smoothes wages across rainfall states by inducing changes in labor supply. Policy simulations based on our estimates suggest that selling insurance only to land-owning cultivators and precluding the landless from the insurance market (which is the current regulatory practice in India and other developing countries), makes wage laborers worse off relative to a situation where insurance does not exist at all. The general-equilibrium analysis reveals that the welfare costs of current regulation are borne by landless laborers, who represent the poorest segment of society and whose risk management options are the most limited.
title: Fractional Cointegration and the Demand for M1
Creators: name: Tkacz, Greg
Publisher: name: Bank of Canada
Year: 2000

description: Using wavelets, the author estimates the fractional order of integration of a common long-run money-demand relationship whose parameters are obtained from a full-information maximum-likelihood procedure. Because the order of integration is found to be significantly higher than zero, a grid-search procedure is used over the local parameter space to isolate the parameters required to lower the fractional order of integration. When Canadian data from 1968–99 are examined, a 25 per cent reduction in the interest semi-elasticity, accompanied by a corresponding increase in the income elasticity, is required to render the equilibrium relationship more stationary. However, given the large standard errors around the estimates of the fractional order of integration, the improvement in the estimate of the cointegration relationship is relatively modest. This suggests that money, output, prices, and interest rates are, at best, fractionally cointegrated.
description: L'auteur a recours aux ondelettes pour estimer l'ordre d'intégration fractionnaire d'une fonction type de demande de monnaie à long terme dont il a obtenu les paramètres à l'aide d'une technique de calcul du maximum de vraisemblance à information complète. L'ordre d'intégration s'étant révélé nettement supérieur à zéro, l'auteur se livre à une recherche manuelle dans l'espace local des paramètres afin de déterminer les valeurs que ceux-ci doivent prendre pour que l'ordre d'intégration fractionnaire diminue. Lorsqu'on utilise les données canadiennes relatives à la période 1968–99, il faut réduire de 25 % la semi-élasticité par rapport au taux d'intérêt et accroître d'autant l'élasticité par rapport au revenu pour diminuer le degré de non-stationnarité de la relation d'équilibre. Toutefois, étant donné l'ampleur des écarts-types qui entourent l'estimation de l'ordre d'intégration fractionnaire, l'amélioration obtenue en ce qui concerne le degré de cointégration est relativement modeste. Ce résultat donne à penser que la monnaie, la production, les prix et les taux d'intérêt sont, au mieux, des séries cointégrées d'ordre fractionnaire.
Factors affecting efficiency of field crop production among resettled farmers in Zimbabwe
Creators: name: Musemwa, L.
name: Mushunje, Abbyssinia
name: Muchenje, V.
name: Aghdasi, F.
name: Zhou, L.
name: Musemwa, L.
name: Mushunje, Abbyssinia
name: Muchenje, V.
name: Aghdasi, F.
name: Zhou, L.
Publisher: name: Unknown
Year: 2013
Subjects: subject: Farm Management
subject: Production Economics
subject: Productivity Analysis
subject: farm size
subject: inefficiencies
subject: production knowledge
subject: resettled farmers
subject: Tobit model

description: A Tobit model censored at zero was selected to examine factors explaining differences in production efficiency amongst resettled farmers. Efficiency scores obtained from Data Envelop Analysis (DEA) were used as the dependent variable. From the factors inputted in the model, age of household head, excellent production knowledge and level of specialisation affected technical efficiency. Allocative efficiency was only affected by good production knowledge, farm size, arable land owned and area under cultivation. Factors which affected economic efficiency of the resettled farmers were secondary education, household size, farm size, cultivated area and arable land owned. None of the included socio-economic variables had significant effects on the allocative and economic efficiency of the resettled farmers. Thus, the allocative and economic inefficiencies of the farmers might have been accounted for by other natural and environmental factors which were not captured in the model. Efficiency of the resettled farmers can be improved significantly if the government focuses on increasing the education level of farming communities. The promotion of large farms through the establishment of co-operatives could also improve efficiency of the resettled farmers.
MOESM3 of Professional barriers and facilitators to using stratified care approaches for managing non-specific low back pain: a qualitative study with Canadian physiotherapists and chiropractors
Creators: name: Zoubi, Fadi AL
name: French, Simon
name: Patey, Andrea
name: Mayo, Nancy
name: Bussières, André
Publisher: name: figshare
Year: 2019
Subjects: subject: Cell Biology
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: Cancer
subject: Science Policy

description: Additional file 3. Findings of relevant domains together with illustrative quotes for chiropractors.
Statistical significance of fine structure in the frequency spectrum of Aharonov-Bohm conductance oscillations
Creators: name: Meijer, F. E.
name: Morpurgo, A. F.
name: Klapwijk, T. M.
name: Nitta, J.
name: Koga, T.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We discuss a statistical analysis of Aharonov-Bohm conductance oscillations measured in a two-dimensional ring, in the presence of Rashba spin-orbit interaction. Measurements performed at different values of gate voltage are used to calculate the ensemble-averaged modulus of the Fourier spectrum and, at each frequency, the standard deviation associated to the average. This allows us to prove the statistical significance of a splitting that we observe in the h/e peak of the averaged spectrum. Our work illustrates in detail the role of sample specific effects on the frequency spectrum of Aharonov-Bohm conductance oscillations and it demonstrates how fine structures of a different physical origin can be discriminated from sample specific features.
description: accepted for publication in PRB
title: Employment Effects Of Nominal-Wage Rigidity: An Examination Using Wage-Settlements Data
Creators: name: Faruqui, Umar Ahmed
Publisher: name: Bank of Canada
Year: 2000

description: The argument advocating a moderate level of inflation based on the downward nominal-wage rigidity (DNWR) hypothesis rests on three factors: its presence, extent, and negative impact in the labour market. This paper focuses on the employment effect of DNWR. It reviews the evidence presented by Simpson, Cameron, and Hum (1998), in light of a potential bias problem associated with their reduced-form model. We describe modifications to their employment model that aim to better isolate the effects of DNWR on employment growth. Analysis shows that empirical evidence in Simpson, Cameron, and Hum (1998) is sensitive to model specification. In contrast to Simpson, Cameron, and Hum (1998), who found—economically and statistically—significant employment costs for DNWR, in most of our specifications DNWR has no significant effect on employment growth.
description: Ceux qui invoquent l'hypothèse de rigidité à la baisse des salaires nominaux pour préconiser le maintien d'un taux d'inflation modéré fondent leur argumentation sur la présence et le degré de rigidité des salaires nominaux ainsi que sur les effets négatifs d'une telle rigidité sur le marché du travail. L'auteur de l'étude résumée ici s'attache tout particulièrement à l'incidence de la rigidité des salaires nominaux sur l'emploi. Il examine les résultats présentés par Simpson, Cameron et Hum (1998) et cherche à établir si le modèle à forme réduite de ces derniers est entaché d'un biais. L'auteur décrit les modifications qu'il a apportés à leur modèle de l'emploi afin de mieux cerner les effets d'une rigidité à la baisse des salaires nominaux sur la croissance de l'emploi. Il constate que les résultats empiriques obtenus par Simpson, Cameron et Hum sont sensibles à la spécification du modèle. Alors que, d'après ces chercheurs, la rigidité des salaires nominaux a sur la croissance de l'emploi des effets négatifs qui sont significatifs sur les plans tant économique que statistique, l'auteur n'observe aucun effet significatif de cette nature dans la majorité des spécifications retenues.
Glass façade upper floor, exhibition stand TOYOTA, IAA 2005
Creators: name: Kramer, M.
Publisher: name: Challenging Glass Conference Proceedings
Year: 2010

description: Modern designs of exhibition stands, especially for motor shows, require more and more transparency. To meet the designers‘ demands, it becomes necessary to use glass not only as an element of design, but also as a load bearing element of the structure. To give an example how the use of glass leads to an impressive result, the structure of the glass façade around the upper floor of the exhibition stand TOYOTA at the IAA 2005 will be described. The façade had a height of 2.8m and was built over a length of 13.5m without any supporting elements. Glass panes at the short side braced the structure by structural silicone bonding glass/aluminum. In the corners curved glass elements with a very small radius of 465 mm were used. All glass panes worked as glass to prevent from falling. The results from the pendulum impact test of the curved glasses will be shown. Finally the experiences with the structure related to production, mounting etc. will be concluded.
description: Challenging Glass Conference Proceedings, Vol. 2 (2010): Challenging Glass 2
Reconsidering the origin of the X-ray emission lines in GRB 011211
Creators: name: Tavecchio, Fabrizio
name: Ghisellini, Gabriele
name: Lazzati, Davide
Publisher: name: arXiv
Year: 2003
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We reanalyze the XMM--Newton data of GRB 011211 showing that the spectral features, interpreted by Reeves et al. (2002, 2003) as due thermal emission from a collisionally ionized plasma, can be also reproduced by a reflection model (with ionization parameter $ξ\sim 10^2$). We discuss the implications of this interpretation, estimating the total mass required in the simplified case of a funnel geometry. We conclude that a moderate clumping of the reprocessing material (corresponding to a filling factor of the order of $f\sim 10^{-3}$) is required. Finally we show that, if this interpretation is correct, a bright quasi--thermal component is expected in the optical--UV band (containing about 90% of the luminosity of the illuminating continuum), whose presence can be used to test the reflection model.
description: revised version accepted for publication by A&A
Additional file 1 of Image-based AI diagnostic performance for fatty liver: a systematic review and meta-analysis
Creators: name: Zhao, Qi
name: Lan, Yadi
name: Yin, Xunjun
name: Wang, Kai
Publisher: name: figshare
Year: 2023
Subjects: subject: Artificial Intelligence and Image Processing
subject: FOS: Computer and information sciences

description: Supplementary Material 1: Table S1. Search strategies; Table S2. Description of QUADAS-AI; Table S3. Performance of models from 15 included studies; Table S4. Pooled effects and Heterogeneity in subgroup analysis; Figure S1. Quality assessment of included articles using the QUADAS-AI criteria.
Quantum Friction of Micromechanical Resonators at Low Temperatures
Creators: name: Ahn, Kang-Hun
name: Mohanty, Pritiraj
Publisher: name: arXiv
Year: 2003
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Dissipation of micro- and nano-scale mechanical structures is dominated by quantum-mechanical tunneling of two-level defects intrinsically present in the system. We find that at high frequencies--usually, for smaller, micron-scale structures--a novel mechanism of phonon pumping of two-level defects gives rise to weakly temperature-dependent internal friction, $Q^{-1}$, concomitant to the effects observed in recent experiments. Due to their size, comparable to or shorter than the emitted phonon wavelength, these structures suffer from superradiance-enhanced dissipation by the collective relaxation of a large number of two-level defects contained within the wavelength.
description: To apear in Phys. Rev. Lett
Inklusive Medienbildung mit der App *Theodor und das Schreiben der Stadt*. Konzeption von Unterrichtsmaterialien zur Medienbildung von Kindern mit und ohne Lernschwierigkeiten
Creators: name: Mensching, Franziska
Publisher: name: Universität Bielefeld
Year: 2020
Subjects: subject: 370

description: Vor dem Hintergrund des Wandels des Arbeitsmarktes sowie der neuen Chancen und Herausforderungen durch digitale Medien, erscheint eine umfassende Medienbildung für Schüler\*innen mit Lernschwierigkeiten unabdingbar. In dieser Arbeit wurde daher der Frage nachgegangen, wie Unterrichtsmaterialien konzipiert werden können, damit Schüler\*innen mit und ohne Lernschwierigkeiten in inklusiven Lerngruppen von einer inklusiven Medienbildung profitieren können. Auf der Grundlage einer theoretischen Auseinandersetzung mit den Schwerpunkten inklusiver Unterricht, Förderschwerpunkt Lernen und Lernschwierigkeiten, inklusive Medienbildung und dem Themenfeld Online-Kommunikation wurden Kriterien für solche Unterrichtsmaterialien entwickelt und erprobt. So wurden die Kriterien für die Konzeption und exemplarische Ausarbeitung von eigenen Unterrichtsmaterialien zu einer App für Schüler\*innen ab der 3. Klasse genutzt. Dabei zeigte sich, dass sich einige Kriterien gegenseitig ausschließen (z. B. Einsatz digitaler Medien ohne rechtliche oder technische Anforderungen) oder sich zugunsten anderer nur eingeschränkt umsetzen lassen (z. B. komplexerer Einsatzmöglichkeit zugunsten einer hohen Anpassbarkeit). Als besondere Herausforderung wurden insbesondere solche Kriterien gesehen, die nicht allein durch das Material gewährleistet werden können. So kann beispielsweise eine Wertschätzung von Vielfalt zwar durch strukturell-didaktische Vorkehrungen und geeignete Hinweise im Material gefördert, ein diskriminierendes Verhalten von Seiten der Lehrkräfte und Schüler\*innen jedoch nicht ausgeschlossen werden.
Leptogenesis
Creators: name: Paschos, E. A.
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: I present the theoretical basis for Leptogenesis and its implications for the structure of the universe. It is suggested that density fluctuations grow during the transition period and remnants of this effect should be sought in the universe. The relation between theories with Majorana neutrinos and low energy phenomena, including oscillations, advanced considerably during the past two years with a consistent picture developed in several models.
description: 9 pages, 3 figures.To appear in the proceedings of The IXth International Symposium on Particles, Strings and Cosmology at the Tata Institute of Fundamental Research, Mumbai (Bombay), India, during 3-8 January 2003
title: Volatility Transmission Between Foreign Exchange and Money Markets
Creators: name: Ebrahim, Shafiq K.
Publisher: name: Bank of Canada
Year: 2000

description: This paper uses trivariate generalized autoregressive conditional heteroscedasticity (GARCH) models to study price and volatility spillovers between the foreign exchange and associated money markets. Three models are estimated using data on U.S. dollar/Canadian dollar, U.S. dollar/Deutsche mark, and U.S. dollar/Japanese yen daily exchange rate returns together with returns on 90-day Eurodollar, Euro Canada, Euromark, and Euroyen deposits. The paper finds strong evidence of price and volatility spillovers in all three models, and some volatility spillovers are found to be asymmetric. Although the volatilities of some innovations share common features, pairwise contemporaneous correlations between innovations in the three models are generally low. These results suggest either that common factors between markets are small with investors in one market processing information from other markets gradually or that the spillovers are the result of market contagion effects. The paper also outlines the ramifications of these findings from the perspective of economic policy-makers.
description: À l'aide de modèles GARCH à trois variables, l'auteur étudie la propagation des prix et de leur volatilité entre les marchés des changes et les marchés monétaires correspondants. Il estime trois modèles au moyen de données relatives aux rendements quotidiens réalisés sur le marché du dollar É.-U. contre le dollar canadien, contre le deutsche mark et contre le yen et sur le marché des dépôts à 90 jours en eurodollars américains et canadiens, en euromarks et en euroyens. Les résultats obtenus à l'aide des trois modèles militent fortement en faveur de la propagation entre les marchés; dans certains cas, la volatilité des prix se propagerait de façon asymétrique. Bien que les volatilités aient parfois des traits en commun, les corrélations contemporaines entre chocs pris deux à deux sont faibles dans chacun des trois modèles. Ces résultats peuvent s'expliquer de deux façons : soit qu'il existe peu de facteurs communs aux différents marchés, les investisseurs actifs sur un marché assimilant graduellement l'information qui provient des autres marchés, soit que la propagation entre les marchés résulte d'effets de contagion. L'auteur souligne aussi les conclusions que peuvent en tirer les responsables des politiques économiques.
Neural Gaussian Copula for Variational Autoencoder
Creators: name: Wang, Prince Zizhuang
name: Wang, William Yang
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Variational language models seek to estimate the posterior of latent variables with an approximated variational posterior. The model often assumes the variational posterior to be factorized even when the true posterior is not. The learned variational posterior under this assumption does not capture the dependency relationships over latent variables. We argue that this would cause a typical training problem called posterior collapse observed in all other variational language models. We propose Gaussian Copula Variational Autoencoder (VAE) to avert this problem. Copula is widely used to model correlation and dependencies of high-dimensional random variables, and therefore it is helpful to maintain the dependency relationships that are lost in VAE. The empirical results show that by modeling the correlation of latent variables explicitly using a neural parametric copula, we can avert this training difficulty while getting competitive results among all other VAE approaches.
description: 11 pages
title: A Practical Guide to Swap Curve Construction
Creators: name: Ron, Uri
Publisher: name: Bank of Canada
Year: 2000

description: The swap market has enjoyed tremendous growth in the last decade. With government issues shrinking in supply and increased price volatilities, the swap term structure has emerged as an alternative pricing, benchmark, and hedging mechanism to the government term structure. This paper outlines the advantages of using the swap curve, and provides a detailed methodology for deriving the swap term structure for marking to market fixed-income products. The paper concludes with a discussion of the proposed swap term structure derivation technique.
description: Le marché des swaps a connu un essor prodigieux durant les années 1990. Avec la réduction de l'offre des titres d'état et la volatilité accrue de leurs prix, la structure à terme des taux de swaps offre une solution de rechange à celle des emprunts d'état, établissant ainsi une nouvelle courbe de référence pour l'évaluation des titres à revenu fixe et la couverture des risques. L'auteur décrit les avantages que présente l'utilisation de la courbe des taux de swaps et expose en détail une méthode permettant de déterminer celle-ci pour fins d'évaluation des prix au marché des titres à revenu fixe. L'auteur conclut sur une discussion de la méthode qu'il propose.
Topological charge pumping in twisted bilayer graphene
Creators: name: Zhang, Yinhan
name: Gao, Yang
name: Xiao, Di
Publisher: name: arXiv
Year: 2019
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that a sliding motion between the two layers of a \moire superlattice induces an electric current and realizes a two-dimensional version of the topological Thouless pump when the Fermi energy lies in one of the minigaps. Interestingly, a chiral charge pump, namely, a transverse current induced by the sliding motion, is possible in twisted homobilayers. This result is confirmed by a concrete calculation of the adiabatic current in twisted bilayer graphene. Our work reveals an interesting link between mechanical motion and electricity unique to \moire superlattices, and may find applications in nanogenerators and nanomotors.
description: 5 pages, 3 figures. Minor typos corrected
title: Inflation and the Tax System in Canada: An Exploratory Partial-Equilibrium Analysis
Creators: name: O’Reilly, Brian
name: Levac, Mylène
Publisher: name: Bank of Canada
Year: 2000

description: This paper reports on an exploratory application to Canadian data of an approach pioneered by Martin Feldstein (1997, 1999). Feldstein finds that even at low inflation rates there are costs arising from the distortions introduced by the interaction of inflation with the taxation of income from capital (capital gains, dividends, and interest) in a less-than-perfectly-indexed tax system. Given the exploratory nature of our work, only the main aspects of the conceptual basis of this approach are sketched, and very rough-and-ready estimates for inputs and outputs reported. The economically significant welfare costs of inflation obtained when this approach is applied to Canada arise mainly from distortions in the timing of consumption and saving. However, our reservations about the approach have not led us to refine the estimates or to indicate a preferred estimate.
description: L'étude présente les résultats de l'application aux données canadiennes, à titre expérimental, d'une approche proposée initialement par Feldstein (1997 et 1999). Ce dernier constate que, même à de bas taux d'inflation, l'interaction de l'inflation et de l'imposition des revenus tirés de placements (gains en capital, dividendes et intérêts) dans un régime fiscal imparfaitement indexé entraîne des distorsions coûteuses. Compte tenu du caractère exploratoire de leur recherche, les auteurs se contentent d'esquisser à grands traits le fondement conceptuel de la démarche de Feldstein et de présenter des estimations rudimentaires pour les données utilisées et les résultats obtenus. Les effets négatifs de l'inflation sur le bien-être, qui se révèlent importants du point de vue économique lorsque cette approche est appliquée au cas canadien, découlent surtout des distorsions liées à l'absence de synchronisme entre les activités de consommation et d'épargne. Toutefois, en raison de leurs réserves au sujet de l'approche de Feldstein, les auteurs se sont abstenus de peaufiner leurs estimations ou d'indiquer lesquelles leur semblent les plus plausibles.
title: Le modèle USM d'analyse et de projection de l'économie américaine
Creators: name: Lalonde, René
Publisher: name: Bank of Canada
Year: 2000

description: Dans cette étude, l'auteur présente un nouveau modèle de prévision et d'analyse de l'économie américaine (c.-à.-d. le modèle USM) construit à la Banque du Canada. Comparativement au mo-dèle précédent (le VSM), le USM comporte plusieurs avantages. Premièrement, il utilise les nou-velles méthodes d'identification du PIB potentiel basées sur les VAR structurels. Deuxièmement, il permet de mieux prendre en compte les caractéristiques actuelles de l'économie américaine (no-tamment le « boom » de la productivité) et d'endogénéiser les taux d'intérêt. Troisièmement, il tente de combler les lacunes du VSM en ce qui a trait au traitement de la politique budgétaire. Enfin, il vise à intégrer la notion de crédibilité de la politique monétaire par le biais de la spécification des anticipations inflationnistes. Le USM est constitué notamment d'une courbe de Phillips, d'une courbe IS et d'une fonction de réaction des autorités monétaires. Les anticipations inflationnistes sont centrées autour de la cible basée sur le taux d'inflation. La courbe de Phillips est spécifiée en termes de l'écart de production et elle prend en compte les effets de la productivité sur l'inflation. La fonction de réaction est similaire à la règle de Taylor. Le comportement dynamique du modèle et l'interrelation entre les différentes variables semblent compatibles avec la théorie économique et la littérature empirique. La prochaine étape des travaux d'expansion du USM consistera à déve-lopper le taux de change et à intégrer au modèle le secteur extérieur.
description: In this study, the author presents a new forecast and analysis model for the U.S. economy (i.e., the USM model) constructed at the Bank of Canada. The USM has a number of advantages over its predecessor, the VSM model. First, it utilizes new methods of identifying potential GDP based on structural VARs. Second, it makes it possible to take better account of the current characteristics of the U.S. economy (notably the productivity boom) and to endogenize interest rates. Third, it tries to correct the VSM's shortcomings with respect to treatment of fiscal policy. Finally, it attempts to incorporate the notion of credibility of monetary policy through expectations of inflation. The USM features a Phillips curve, an IS curve, and a function representing the reaction of monetary authorities. Expectations of inflation are centred on the inflation target. The Phillips curve is specified in terms of the output gap and takes the effects of productivity on inflation into account. The reaction function is similar to Taylor's rule. The dynamic behaviour of the model and the interaction among the different variables seem to be consistent with economic theory and empirical literature. The next step in expanding the USM will be to develop the exchange rate and integrate the foreign sector.
MOESM2 of Professional barriers and facilitators to using stratified care approaches for managing non-specific low back pain: a qualitative study with Canadian physiotherapists and chiropractors
Creators: name: Zoubi, Fadi AL
name: French, Simon
name: Patey, Andrea
name: Mayo, Nancy
name: Bussières, André
Publisher: name: figshare
Year: 2019
Subjects: subject: Cell Biology
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: Cancer
subject: Science Policy

description: Additional file 2. Findings of relevant domains together with illustrative quotes for physiotherapists.
Urbanization and Poverty Reduction – The Role of Rural Diversification and Secondary Towns
Creators: name: Christiaensen, Luc
name: De Weerdt, Joachim
name: Todo, Yasuyuki
name: Christiaensen, Luc
name: De Weerdt, Joachim
name: Todo, Yasuyuki
Publisher: name: Unknown
Year: 2013
Subjects: subject: Community/Rural/Urban Development
subject: Food Security and Poverty
subject: Poverty
subject: rural-urban transformation
subject: rural non-farm economy
subject: structural transformation
subject: urban concentration

description: A rather unique panel tracking more than 3300 individuals from households in rural Kagera, Tanzania during 1991/4-2010 shows that about 1 out of 2 individuals/households who exited poverty did so by transitioning out of agriculture into the rural nonfarm economy or secondary towns. Only 1 out of 7 exited poverty by migrating to the big cities, even though those moving to the city experienced on average faster consumption growth. Further analysis of a much larger cross-country panel of 51 developing countries cannot reject that rural diversification and secondary town development lead to more inclusive growth patterns than metropolitization. Indications are that this follows because more of the poor find their way to the rural nonfarm economy and secondary towns, than to distant cities. The development discourse would benefit from shifting beyond the rural-urban dichotomy and focusing more instead on how best to urbanize and develop its rural nonfarm economy and secondary towns.
Nonreciprocal response theory of nonhermitian mechanical metamaterials: response phase transition from the skin effect of zero modes
Creators: name: Schomerus, Henning
Publisher: name: arXiv
Year: 2019
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Nonreciprocal nonhermitian systems provide an unconventional localization mechanism of topological zero modes via the nonhermitian skin effect. While fundamental theoretical characterizations of this effect involve the biorthogonal system of right and left eigenmodes, the recent demonstration of this effect for a zero mode in a robotic metamaterial (Ghatak et al., arXiv:1907.11619) is based on the direct experimental observation of the conventional right eigenvectors. Here I show that such nonreciprocal mechanical metamaterials reveal their underlying biorthogonality in the directly observable response of the system to external excitation. Applied to the ground-breaking experiment, this nonreciprocal response theory predicts that the zero-mode skin effect goes along an extended phase where the system is highly sensitive to physical perturbations, leading to a diverging response in the limit of a large system.
description: 5 pages, 3 figures