cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Unveiling optical signatures of outflows in accreting white dwarfs
Creators: name: Cúneo, V. A.
name: Muñoz-Darias, T.
name: Jiménez-Ibarra, F.
name: Panizo-Espinar, G.
name: Sánchez-Sierras, J.
name: Padilla, M. Armas
name: Casares, J.
name: Sánchez, D. Mata
name: Torres, M. A. P.
name: Vincentelli, F.
name: Ambrifi, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Accreting white dwarfs are known to show signatures of wind-type outflows in the ultraviolet. At optical wavelengths, however, wind detections have only been reported for a few sources. We present GTC-10.4m optical spectroscopy of four accreting white dwarfs (BZ Cam, V751 Cyg, MV Lyr, and V425 Cas) observed during luminous epochs, when their optical emission is expected to be dominated by the accretion disc. We focused the analysis on four emission lines: H$α$ and He I $λ$5876, $λ$6678, $λ$7065. Line profiles are complex and variable on short (minutes) and long (days to weeks) time scales, with transient absorption and emission components. Among them, we detect strong blue-shifted absorptions at $\gtrsim 1000$ km s$^{-1}$. These high-velocity components, present only in the blue wing of the emission lines, are observed in all four sources and could be associated with accretion disc winds. For MV Lyr and V425 Cas, these would represent the first detection of optical outflows in these objects, while in the case of BZ Cam and V751 Cyg, the presence of outflows has been previously reported. This study suggests that, in addition to ultraviolet winds, optical outflows might be also common in accreting white dwarfs. We discuss the observational properties of these winds and their possible similarity to those detected in accreting black holes and neutrons stars.
description: Accepted for publication in A&A
Spin-pumping and Enhanced Gilbert Damping in Thin Magnetic Insulator Films
Creators: name: Kapelrud, André
name: Brataas, Arne
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Precessing magnetization in a thin film magnetic insulator pumps spins into adjacent metals; however, this phenomenon is not quantitatively understood. We present a theory for the dependence of spin-pumping on the transverse mode number and in-plane wave vector. For long-wavelength spin waves, the enhanced Gilbert damping for the transverse mode volume waves is twice that of the macrospin mode, and for surface modes, the enhancement can be ten or more times stronger. Spin-pumping is negligible for short-wavelength exchange spin waves. We corroborate our analytical theory with numerical calculations in agreement with recent experimental results.
Are there more galaxies than we see around high-$z$ quasars?
Creators: name: Zana, Tommaso
name: Carniani, Stefano
name: Prelogović, David
name: Vito, Fabio
name: Allevato, Viola
name: Ferrara, Andrea
name: Gallerani, Simona
name: Parlanti, Eleonora
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Whether or not $z \gtrsim 6$ quasars lie in the most massive dark-matter halos of the Universe is still a subject of dispute. While most theoretical studies support this scenario, current observations yield discordant results when they probe the halo mass through the detection rate of quasar companion galaxies. Feedback processes from supermassive black holes and dust obscuration have been blamed for this discrepancy, but the impact of these effects is complex and far from being clearly understood. This paper aims to improve the interpretation of current far-infrared observations by taking into account the cosmological volume probed by the Atacama Large Millimeter/submillimeter Array Telescope and to explain the observational discrepancies. We statistically investigate the detection rate of quasar companions in current observations and verify if they match the expected distribution from various theoretical models, once convolved with the ALMA field-of-view, through the use of Monte Carlo simulations. We demonstrate that the telescope geometrical bias is fundamental and can alone explain the scatter in the number of detected satellite galaxies in different observations. We conclude that the resulting companion densities depend on the chosen galaxy distributions. According to our fiducial models, current data favour a density scenario where quasars lie in dark-matter halos of viral mass $M_{\rm vir} \gtrsim 10^{12}~{\rm M_{\odot}}$, in agreement with most theoretical studies. According to our analysis, each quasar has about 2 companion galaxies, with a [CII] luminosity $L_{\rm [CII]} \gtrsim 10^8~{\rm L}_{\odot}$, within a distance of about 1~Mpc from the quasar.
description: 7 pages, 5 figures; accepted for publications in A&A
Irrespective Priority-Based Regular Properties of High-Intensity Virtual Environments
Creators: name: Sorudeykin, Kirill A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We have a lot of relation to the encoding and the Theory of Information, when considering thinking. This is a natural process and, at once, the complex thing we investigate. This always was a challenge - to understand how our mind works, and we are trying to find some universal models for this. A lot of ways have been considered so far, but we are looking for Something, we seek for approaches. And the goal is to find a consistent, noncontradictory view, which should at once be enough flexible in any dimensions to allow to represent various kinds of processes and environments, matters of different nature and diverse objects. Developing of such a model is the destination of this article.
description: 4 pages, 2 figures; ISBN: 978-1-4673-2984-2
A Deductive Verification Infrastructure for Probabilistic Programs (Extended Version)
Creators: name: Schröer, Philipp
name: Batz, Kevin
name: Kaminski, Benjamin Lucien
name: Katoen, Joost-Pieter
name: Matheja, Christoph
Publisher: name: arXiv
Year: 2023
Subjects: subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: This paper presents a quantitative program verification infrastructure for discrete probabilistic programs. Our infrastructure can be viewed as the probabilistic analogue of Boogie: its central components are an intermediate verification language (IVL) together with a real-valued logic. Our IVL provides a programming-language-style for expressing verification conditions whose validity implies the correctness of a program under investigation. As our focus is on verifying quantitative properties such as bounds on expected outcomes, expected run-times, or termination probabilities, off-the-shelf IVLs based on Boolean first-order logic do not suffice. Instead, a paradigm shift from the standard Boolean to a real-valued domain is required. Our IVL features quantitative generalizations of standard verification constructs such as assume- and assert-statements. Verification conditions are generated by a weakest-precondition-style semantics, based on our real-valued logic. We show that our verification infrastructure supports natural encodings of numerous verification techniques from the literature. With our SMT-based implementation, we automatically verify a variety of benchmarks. To the best of our knowledge, this establishes the first deductive verification infrastructure for expectation-based reasoning about probabilistic programs.
description: This is the extended version of the the publication at OOPSLA 2023 (https://doi.org/10.1145/3622870)
Bi-Lipschitz A-equivalence of K-equivalent map germs
Creators: name: Costa, Joao Carlos Ferreira
name: Nishimura, Takashi
name: Ruas, Maria Aparecida Soares
Publisher: name: arXiv
Year: 2013
Subjects: subject: Algebraic Geometry (math.AG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 58K15, 58K25, 58K60

description: In this paper, two sufficient conditions are provided for given two K-equivalent map-germs to be bi-Lipschitz A-equivalent. These are Lipschitz analogues of the known results on C^r-A-equivalence $(0 \leq r \leq \infty)$ for given two K-equivalent map-germs. As a corollary of one of our results, a Lipschitz version of the well-known Fukuda-Fukuda theorem is provided.
description: Published online in Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales. Serie A. Matematicas 2012
Effects of Interference between Energy Absorption Processes of Molecule and Surface Plasmons on Light Emission Induced by Scanning Tunneling Microscopy
Creators: name: Miwa, Kuniyuki
name: Sakaue, Mamoru
name: Kasai, Hideaki
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Effects of coupling between an molecular exciton and a surface plasmon (exciton-plasmon coupling) on the luminescence properties of the molecule and the surface plasmons are investigated using nonequilibrium Green's function method. Molecular absorption and enhancement by molecular electronic and vibrational modes (molecular modes) lead to dip and peak structures in the luminescence spectra of the surface plasmons. The re-absorption by the surface plasmons leads to a dent structure in their luminescence spectra. It is found that the processes of the molecular absorption and the re-absorption by the surface plasmons interfere with each other. Enhancement and suppression of these energy-absorption processes are due to the interference. Moreover, due to the exciton-plasmon coupling, excitation channels of the molecule arise in the energy range lower than the first electronic excitation energy of the molecule. It is found that the electron transitions via these excitation channels give rise to the molecular luminescence and the vibrational excitations at the bias voltage lower than the ratio of the first electronic excitation energy of the molecule to the elementary charge. The results also indicate that the vibrational excitations assist the emission of photons, whose energy exceeds the product of the elementary charge and the bias voltage (upconverted luminescence).
description: arXiv admin note: text overlap with arXiv:1212.0081
Universal interatomic potential for perovskite oxides
Creators: name: Wu, Jing
name: Yang, Jiyuan
name: Liu, Yuan-Jinsheng
name: Zhang, Duo
name: Yang, Yudi
name: Zhang, Yuzhi
name: Zhang, Linfeng
name: Liu, Shi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: With their celebrated structural and chemical flexibility, perovskite oxides have served as a highly adaptable material platform for exploring emergent phenomena arising from the interplay between different degrees of freedom. Molecular dynamics (MD) simulations leveraging classical force fields, commonly depicted as parameterized analytical functions, have made significant contributions in elucidating the atomistic dynamics and structural properties of crystalline solids including perovskite oxides. However, the force fields currently available for solids are rather specific and offer limited transferability, making it time-consuming to use MD to study new materials systems since a new force field must be parameterized and tested first. The lack of a generalized force field applicable to a broad spectrum of solid materials hinders the facile deployment of MD in computer-aided materials discovery (CAMD). Here, by utilizing a deep-neural network with a self-attention scheme, we have developed a unified force field that enables MD simulations of perovskite oxides involving 14 metal elements and conceivably their solid solutions with arbitrary compositions. Notably, isobaric-isothermal ensemble MD simulations with this model potential accurately predict the experimental phase transition sequences for several markedly different ferroelectric oxides, including a 6-element ternary solid solution, Pb(In$_{1/2}$Nb$_{1/2}$)O$_3$--Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$--PbTiO$_3$. We believe the universal interatomic potential along with the training database, proposed regression tests, and the auto-testing workflow, all released publicly, will pave the way for a systematic improvement and extension of a unified force field for solids, potentially heralding a new era in CAMD.
description: 18 pages, 4 figures
Rainfall disaggregation for hydrological modeling: Is there a need for spatial consistence?
Creators: name: Müller, Hannes
name: Wallner, Markus
name: Förster, Kristian
name: Haberlandt, Uwe
Publisher: name: München : European Geosciences Union
Year: 2017
Subjects: subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften
subject: Dewey Decimal Classification::500 | Naturwissenschaften::551 | Geologie, Hydrologie, Meteorologie

description: Rainfall data with a high temporal resolution is required for rainfall-runoff modeling. Observed time series of this kind are short and can thus not be used in most cases. However, time series with daily resolution exist for longer periods and denser networks. The objective is to derive time series with a long duration and a high resolution by disaggregating time series of the non-recording stations with information of high-resolution time series. The multiplicative random cascade model can be used for temporal rainfall disaggregation. It disaggregates time series without consideration of time series of other surrounding stations. This method (hereafter referred to as method 0) yields unrealistic spatial patterns of rainfall if it is applied to more than one station since the sub-daily rainfall is distributed randomly in time for each site. Two methods are analyzed for the subsequently implementation of spatial consistence. Method 1 is based on a simulated annealing algorithm that resamples relative diurnal cycles of the disaggregated time-series with the aim to reproduce spatial dependence of rainfall. Method 2 assigns the relative diurnal cycle of the station with the highest rainfall amount to all other stations for each day. Disaggregated time series using both methods as well as without implemented spatial consistence are used as input for rainfall-runoff modeling in the conceptual, semi-distributed model HBV. Investigation areas are three mesoscale catchments (62-321 km2) in Northern Germany. The results show clear differences between the three approaches with regard to bivariate spatial rainfall characteristics. With the resampling algorithm of method 1 the observed characteristics can be reproduced. With method 0 and method 2 they are underestimated and overestimated, respectively. These differences can also be found for areal rainfall intensities. However, the statistics of the simulated discharge show only slight differences concerning discharge duration curves and derived flood frequencies for summer and winter terms. Results between the three approaches are similar with calibration of the models, without calibration and for different station densities. This poses several questions concerning the influence of spatial rainfall patterns at this scale. Additional investigations are under way, e.g. using WaSiM-ETH as an alternative, more physically based and distributed model.
An asymptotic safety scenario for gauged chiral Higgs-Yukawa models
Creators: name: Gies, Holger
name: Rechenberger, Stefan
name: Scherer, Michael M.
name: Zambelli, Luca
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate chiral Higgs-Yukawa models with a non-abelian gauged left-handed sector reminiscent to a sub-sector of the standard model. We discover a new weak-coupling fixed-point behavior that allows for ultraviolet complete RG trajectories which can be connected with a conventional long-range infrared behavior in the Higgs phase. This non-trivial ultraviolet behavior is characterized by asymptotic freedom in all interaction couplings, but a quasi conformal behavior in all mass-like parameters. The stable microscopic scalar potential asymptotically approaches flatness in the ultraviolet, however, with a non-vanishing minimum increasing inversely proportional to the asymptotically free gauge coupling. This gives rise to nonperturbative -- though weak-coupling -- threshold effects which induce ultraviolet stability along a line of fixed points. Despite the weak-coupling properties, the system exhibits non-Gaussian features which are distinctly different from its standard perturbative counterpart: e.g., on a branch of the line of fixed points, we find linear instead of quadratically running renormalization constants. Whereas the Fermi constant and the top mass are naturally of the same order of magnitude, our model generically allows for light Higgs boson masses. Realistic mass ratios are related to particular RG trajectories with a "walking" mid-momentum regime.
description: 25 pages, 7 figures
Radar data bias correction implementing quantile mapping and investigation of its influence in a hydrological model
Creators: name: Rabiei, Ehsan
name: Wallner, Markus
name: Haberlandt, Uwe
Publisher: name: München : European Geosciences Union
Year: 2014
Subjects: subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften
subject: Dewey Decimal Classification::500 | Naturwissenschaften::551 | Geologie, Hydrologie, Meteorologie

description: Weather radar is an important source of data for estimating rainfall rate with relatively high temporal and spatial resolution covering large areas. Although weather radar provides fine temporal and spatial resolution data, it is subject to different sources of error. Beside casual problems associated with radar, e.g. clutter and attenuation, weather radar either underestimates or overestimates the rainfall amount. Additionally, time steps with strangely high values result in destroying the structure of time series derived from radar data. In order to estimate areal precipitation for hydrological analyses, radar data could be merged with rain gauge network data. The merging product quality is strongly dependent on radar data quality. The main purpose of this study is to illustrate a method for improving radar data quality and to investigate the influence of radar data quality on merging products by means of cross validation. Quantile mapping on the two sources of data, the radar and rain gauge network, is implemented in this study to improve the radar data quality. After correcting the radar data, considering rain gauge data as the truth, the data is implemented into a hydrological model, HBV-IWW, to investigate the influence of the different input sources regarding model performance. It has been observed that implementing quantile mapping improves radar data quality significantly. On the other hand, using radar data after correction not only improves interpolation performances but also reveals other possible applications like disaggregation of daily rainfall data into finer temporal resolutions. Beside radar data quality, there are other factors influencing the model performance like network density and the applied interpolation technique. The study area is a mesoscale catchment located in Lower Saxony, northern Germany.
REeal data AnaLysis GOCE Gravity field determination from GOCE
Creators: name: Krasbutter, Ina
name: Baur, Oliver
name: Brockmann, Jan-Martin
name: Cai, Jianqing
name: Eicker, Annette
name: Kargoll, Boris
name: Kusche, Jürgen
name: Mayer-Gürr, Torsten
name: Schall, Judith
name: Schuh, Wolf-Dieter
name: Shabanloui, Akbar
name: Sneeuw, Nico
Publisher: name: Leibniz Universität Hannover
Year: 2012
Subjects: subject: GOCE
subject: REALGOCE
subject: Gravity field determination with GOCE
subject: Schwerefeldbestimmung mit GOCE
subject: Dewey Decimal Classification::500 | Naturwissenschaften::520 | Astronomie, Kartographie
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: The Earth's gravity field is determined within the BMBF project REeal data AnaLysis GOCE (REALGOCE).
Regionalisation of climate change factors of peak flow quantiles in Lower Saxony
Creators: name: Plötner, Stefan
name: Haberlandt, Uwe
name: Petry, Uwe
Publisher: name: München : European Geosciences Union
Year: 2017
Subjects: subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften

description: In order to project changes in flood flows climate change factors can be used. These are estimated by hydrological modelling for future and historical conditions, deriving flood peak distributions each and calculating ratios of the obtained peak flow quantiles. The changes factors can then be applied to observed or modelled flood quantiles to estimate possible future design flows. To predict in ungauged basins a regionalisation of the change factors is necessary. This utilisation of change factors is assumed to be more robust regarding the bias in climate models, regarding scale problems when using daily time steps for modelling and allows the application to any reference data set. For 178 meso-scale catchments in Lower Saxony the conceptual rainfall-runoff-model HBV-IWW is set up on a lumped and daily basis. The models are calibrated using a multi-criteria optimisation approach for the time period 1951-2013. 8 RCP 8.5 and 6 SRES A1B scenario datasets are used to derive the climate change factors of peak flow quantiles for the far future 2071-2100 against the reference time period 1971-2000. Three different methods: Multiple Linear Regression, Ordinary Kriging and Kriging with External Drift are investigated to regionalise the climate change factors. Due to the uncertainty of future climate an ensemble of simulations is used. This contribution answers questions regarding the best interpolation method, the optimal combination of climate scenarios and the assessment of uncertainty in the prediction.
Relative gravimeter calibration system for high accurate applications
Creators: name: Timmen, Ludger
name: Schilling, Manuel
name: Falk, Reinhard
name: Lothhammer, Alexander
name: Gabriel, Gerald
name: Vogel, Detlef
Publisher: name: München : European Geosciences Union
Year: 2018
Subjects: subject: Relative gravimeter calibration
subject: Vertical Gravimeter Calibration Line Hannover
subject: instrumental air pressure effect
subject: instrumental scale stability
subject: Relativgravimeter Kalibrierung
subject: Vertikale Gravimeter Eichlinie Hannover
subject: instrumenteller Luftdruckeffekt
subject: instrumentelle Maßstabsstabilität
subject: Dewey Decimal Classification::500 | Naturwissenschaften

description: A best possible accuracy for the calibration of relative gravimeters is often required to achieve the objectives of state-geodetic and geo-scientific surveys. A scale inaccuracy for relative gravimeters of 1·10-4 is striven for which allows, e. g., to detect small vertical movements of the Earth’s surface or to avoid misinterpretation of observations showing apparent variations due to uncertain calibration of the relative meters. Recently, the Gravity Meter Calibration System Hannover has been improved with respect to its most important parts: the Harz calibration line (3 absolute gravimetric points) and the Vertical Gravimeter Calibration Line Hannover (VGCH, 20-storey building, 20 relative gravimetric points). For this Upgrade 2017, only “state-of-the-art” measurements with gravimeters from Scintrex (Canada) and ZLS Corporation (USA) have been used. For the two calibration lines, the Upgrade 2017 replaces the solution from 2004 which was based on measurements with LaCoste-Romberg instruments only. In the VGCH, the base connection 210-370 (1st to 17th storey, elevator for transportation) has been obtained with a standard deviation of 11 nm/s². The inaccuracy between adjacent points varies between 5 and 10 nm/s² for the points below the 18th storey. The scale inaccuracy of the Harz calibration line as well as of the VGCH is estimated to be 2·10-4 (expanded uncertainty, confidence interval 95%).
Regionalization of low flow indices in Lower Saxony
Creators: name: Fangmann, Anne
name: Haberlandt, Uwe
Publisher: name: München : European Geosciences Union
Year: 2016
Subjects: subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften

description: For the purpose of finding an effective model to estimate low flow indices at ungauged sites within the Federal State of Lower Saxony in the north of Germany, several approaches for the regionalization of streamflow related variables are tested and evaluated. These include multiple linear regression (MLR), Ordinary Kriging (OK), External Drift Kriging (EDK) and Topological Kriging (TK). In a first preliminary step mean low flow index values are calculated for the period from 1988 to 2009 at gauges with sufficient record length. Records of smaller lengths or temporal deviation from the main period are adjusted using a simple linear regression approach with neighboring long-record stations and are weighted according to model performance. In this way, a total of 238 observed mean index values are obtained throughout the study area that serve as the target variable for all regionalization approaches tested. The first method applied to the data set is the MLR, were the target variable is modeled as a function of various physiographic catchment descriptors. Prediction performance is expected to improve through division of the study area into a set of homogeneous regions, using a k-means clustering approach and fitting an individual regression model for each region. The second set of methods tested is of geostatistical nature. The OK approach is tested by treating catchment centers as points to which the theoretical variogram is fit. The OK is extended by including the catchment descriptors selected as regressors in the MLR model as external drift variables in the EDK. The final method to be applied is the TK, a block-Kriging method accounting for both areal extent and nesting of catchments. Performances of all approaches are evaluated using a cross-validation procedure. The EDK proves as the most successful method when modeling the entire study area, but is outperformed by the MLR approach for homogeneous regions. The single MLR model for the entire study area still shows better performance than the TK. The OK approach turned out to be the least successful among the applied methods. The overall performance of the regionalization methods is rather poor compared to similar case studies, which can be potentially attributed to corrupted streamflow data through anthropogenic intervention.
title: Hotel Asset and Equity Risk Before, During, and After the Global Financial Crisis
Creators: name: Johnson, Marilyn F.
name: Johnson, Mark S.
name: Tessmer, Antoinette C.
Publisher: name: University of Massachusetts Amherst
Year: 2019

description: In this paper, we use asset betas and equity betas over the period January 2000 through December 2015 to investigate the operating and financial risk of hotel industry REITs and C-Corps. We conclude that, on average over our sample period, the operating risk of C-Corps exceeds that of REITs. One interpretation of this result is that management contracts between REITs and C-Corps allocate more operating risk to C-Corps than to REITs. We also find that, on average, during our sample period, the equity betas of C-Corps exceed those of REITs. However, the difference between the average equity risk of the two sectors is much smaller than is the sectors’ difference in operating risk. Because equity betas capture both operating and financial risk, these results imply that REITs have significantly less operating risk than C-Corps and offset their lower business risk with higher financial leverage. During the global financial crisis, operating risk increases in both hotel industry subsectors, and the amount by which C-Corp asset betas exceed REIT asset betas is roughly proportionate to that observed in noncrisis periods. During the financial crisis, however, REITs experienced a greater increase in finan- cial leverage than did C-Corps, with the result being that the normal relation reverses, i.e., during the global financial crisis, REIT average equity betas significantly exceeded the average equity betas of C-Corps.
Sensitivity Analysis of Monopiles’ Fatigue Stresses to Site Conditions Using Monte Carlo Simulation
Creators: name: Glisic, Ana
name: Ferraz, Goncalo T.
name: Schaumann, Peter
Publisher: name: Cupertino : International Society of Offshore and Polar Engineers (ISOPE)
Year: 2017
Subjects: subject: Offshore wind turbines
subject: Monopile structure
subject: Wave load
subject: Monte Carlo simulation
subject: Sensitivity analysis
subject: Sobol’ indices
subject: Windkraft
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::330 | Wirtschaft::333 | Boden- und Energiewirtschaft

description: The design of support structures of offshore wind turbines contains high number of design variables that influence load characteristics and structural responses. These variables are stochastic and cause many uncertainties. Some of them are examined in this study. It is investigated how scattering of site conditions and load parameters affect the structural response. It is exemplified in terms of stresses that contribute to the accumulated fatigue damage within a monopile substructure. Random sampling of combinations of site conditions and load parameters is performed in order to classify the effects of parameter scattering on the stress variability by means of Sobol’ indices. Analysis shows that the highest influence on stress outputs have the variations in the load parameters. The reason is the sensitivity of the structural dynamical response to the wave height increase and decrease of distance between the wave peak frequency and the structural eigenfrequencies. © 2017 ISOPE
Expanding on the Fundamental Metallicity Relation in Dwarf Galaxies with MUSE
Creators: name: Bulichi, Teodora-Elena
name: Fahrion, Katja
name: Mernier, François
name: Hilker, Michael
name: Leaman, Ryan
name: Lyubenova, Mariya
name: Müller, Oliver
name: Neumayer, Nadine
name: Navarro, Ignacio Martin
name: Pinna, Francesca
name: Rejkuba, Marina
name: Scholz-Diaz, Laura
name: van de Ven, Glenn
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The mass-metallicity relation (MZR) represents one of the most important scaling relations in the context of galaxy evolution, comprising a positive correlation between stellar mass and metallicity (Z). The fundamental metallicity relation (FMR) introduces a new parameter, the star formation rate (SFR), in the dependence. While several studies found that Z is anti-correlated with the SFR at fixed mass, the validity of this statement has been questioned extensively and no widely-accepted consensus has been reached yet. With this work, we investigate the FMR in nine nearby, spatially-resolved, dwarf galaxies, using gas diagnostics on integral-field spectroscopic data of the Multi Unit Spectroscopic Explorer (MUSE), pushing such investigations to lower galaxy masses and higher resolutions. We find that both the MZR and FMR exhibit different behaviours within different star forming regions of the galaxies. We find that the SFR surface density - metallicity anti-correlation is tighter in the low-mass galaxies of our sample. For all the galaxies considered, we find a SFR surface density - stellar mass surface density correlation. We propose that the main reason behind these findings is connected to the accretion mechanisms of the gas fuelling star formation -- low-mass, metal-poor galaxies accrete pristine gas from the intergalactic medium, while in more massive and metal-enriched systems the gas responsible for star formation is recycled from previous star forming episodes.
description: 15 pages, 8 figures, accepted for publication in Astronomy & Astrophysics
title: Intangible Assets in Valuation in the Hospitality Industry
Creators: name: Du, Ruixue
name: Li, Yuan
name: Singal, Manisha
Publisher: name: University of Massachusetts Amherst
Year: 2019

description: In publicly traded firms, there is usually a discrepancy between the market value and the book value of the firm, often due to the valuation of intangible assets. Understanding this discrepancy is import- ant for investors, especially in the service industries like hospitality, where there is considerable industry disruption and consolidation. In this study we examine the effect of four intangible asset investments—research and development (R&D), training, advertising, and pension—on the market premium of restaurant firms. Using a longitudinal sample of 1,421 firm-year observations, the results of our analyses show that R&D, training, advertising, and pension are all important valuation con- structs in the hospitality industry, and their effects on market premium vary by restaurant type. This study fills the gap in the current literature by providing a quantitative method to value intangible assets in the hospitality industry. The practical implications of this study will provide managers in the hospitality industry with helpful insights for strategic decision making, specifically regarding R&D, advertising, and employee compensation.
Additional file 1 of The delivery of Ask-Advise-Connect for smoking cessation in Dutch general practice during the COVID-19 pandemic: results of a pre-post implementation study
Creators: name: van Westen-Lagerweij, Naomi A.
name: Willemsen, Marc C.
name: Croes, Esther A.
name: Chavannes, Niels H.
name: Meijer, Eline
Publisher: name: figshare
Year: 2023
Subjects: subject: Medicine
subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Cancer
subject: Science Policy
subject: Computational Biology

description: Additional file 1: Supplementary Table 1. Differences in baseline characteristics between participants included in the analysis and participants not included in the analysis.
From Hubble to Bubble
Creators: name: Kierkla, Maciej
name: Laverda, Giorgio
name: Lewicki, Marek
name: Mantziris, Andreas
name: Piani, Matteo
name: Rubio, Javier
name: Zych, Mateusz
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The detection of a stochastic Gravitational Wave (GW) background sourced by a cosmological phase transition would allow us to see the early Universe from a completely new perspective, illuminating aspects of Beyond the Standard Model (BSM) physics and inflationary cosmology. In this study, we investigate whether the evolution of the scalar potential of a minimal SM extension after inflation can lead to a strong first-order phase transition. In particular, we focus on a BSM spectator scalar field that is non-minimally coupled to gravity and has a dynamical double-well potential. As inflation ends, the potential barrier diminishes due to the evolution of the curvature scalar. Therefore, a phase transition can proceed through the nucleation of true-vacuum bubbles that collide as they fill the Universe and produce GWs. We consider high and low scales of inflation, while also taking into account a kination period between inflation and the onset of radiation domination. With this prescription, we showcase a proof-of-concept study of a new triggering mechanism for BSM phase transitions in the early Universe, whose GW signatures could potentially be probed with future detectors.
description: 17 pages, 5 figures
title: The Tendency of Hotel Rooms Division Managers to Create Budgetary Slack
Creators: name: Ramdeen, Collin
name: Taylor, Marcia
name: Lee, Scott
Publisher: name: University of Massachusetts Amherst
Year: 2019

description: This study explores how the budgeting system impacts rooms department managers’ tendency to create budgetary slack. The results provide support for four hypotheses, specifically indicating that rooms department managers’ tendency to create budgetary slack does change with the setting and the way the budgeting system is implemented. The major practical implication of this study is that allowing rooms department managers to participate actively in the budgeting process seems to reduce their tendencies to create budgetary slack.
A framework for interpreting fast radio transients search experiments: application to the V-FASTR experiment
Creators: name: Trott, Cathryn M.
name: Tingay, Steven J.
name: Wayth, Randall B.
name: Thompson, David R.
name: Deller, Adam T.
name: Brisken, Walter F.
name: Wagstaff, Kiri L.
name: Majid, Walid A.
name: Burke-Spolaor, Sarah
name: Macquart, Jean-Pierre R.
name: Palaniswamy, Divya
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We define a framework for determining constraints on the detection rate of fast transient events from a population of underlying sources, with a view to incorporating beam shape, frequency effects, scattering effects, and detection efficiency into the metric. We then demonstrate a method for combining independent datasets into a single event rate constraint diagram, using a probabilistic approach to the limits on parameter space. We apply this new framework to present the latest results from the V-FASTR experiment, a commensal fast transients search using the Very Long Baseline Array (VLBA). In the 20 cm band, V-FASTR now has the ability to probe the regions of parameter space of importance for the observed Lorimer and Keane fast radio transient candidates, by combining the information from observations with differing bandwidths, and properly accounting for the source dispersion measure, VLBA antenna beam shape, experiment time sampling, and stochastic nature of events. We then apply the framework to combine the results of the V-FASTR and ATA Fly's Eye experiments, demonstrating their complementarity. Expectations for fast transients experiments for the SKA Phase I dish array are then computed, and the impact of large differential bandwidths is discussed.
description: 23 pages, 6 figures. Accepted for publication in The Astrophysical Journal
Non-exotic traversable wormholes in $f\left(R,T_{ab}T^{ab}\right)$ gravity
Creators: name: Rosa, João Luís
name: Ganiyeva, Nailya
name: Lobo, Francisco S. N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work we analyze traversable wormhole spacetimes in the framework of a covariant generalization of Einstein's General Relativity known as energy-momentum squared gravity, or $f\left(R,\mathcal T\right)$ gravity, where $R$ is the Ricci scalar, $\mathcal T=T_{ab}T^{ab}$, and $T_{ab}$ is the energy-momentum tensor. Considering a linear $f\left(R,\mathcal T\right)=R+γ\mathcal T$ form, we show that a wide variety of wormhole solutions for which the matter fields satisfy all the energy conditions, namely the null, weak, strong and dominant energy conditions, exist in this framework, without the necessity for a fine-tuning of the free parameters that describe the model. Due to the complexity of the field equations these solutions are obtained through an analytical recursive algorithm. A drawback of the solutions obtained is that they are not naturally localized, and thus a matching with an external vacuum is required. For that purpose, we derive the junction conditions for the theory, and we prove that a matching between two spacetimes must always be smooth, i.e., no thin-shells are allowed at the boundary. Finally, we use these junction conditions to match the interior wormhole spacetime to an exterior vacuum described by the Schwarzschild solution, thus obtaining traversable localized static and spherically symmetric wormhole solutions satisfying all energy conditions for the whole spacetime range. We also prove that the methods outlined in this work can be straightforwardly generalized to more complicated dependencies of the action in $\mathcal T$, as long as crossed terms between $R$ and $\mathcal T$ are absent.
description: 14 pages, 6 figures
Rate-Distortion Theory for Affine (Global) Motion Compensation in Video Coding
Creators: name: Meuel, Holger
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2018
Subjects: subject: Motion Compensated Prediction
subject: Motion Estimation
subject: Prediction Error
subject: Probability Density Function
subject: Power Spectral Density
subject: Dewey Decimal Classification::000 | Allgemeines, Wissenschaft::000 | Informatik, Wissen, Systeme::004 | Informatik

description: Presentation at the SVCP 2018
Der plastische Bildschmuck an der Fassade des Aachener Rathauses 1864 - 1901
Creators: name: Weinstock, Carola
Publisher: name: Aachener Kunstblätter
Year: 2017

description: -
description: Aachener Kunstblätter, Bd. 49 (1980-1981): Aachener Kunstblätter
Efficient Multiple Object Tracking Using Mutually Repulsive Active Membranes
Creators: name: Deng, Yi
name: Coen, Philip
name: Sun, Mingzhai
name: Shaevitz, Joshua W.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Studies of social and group behavior in interacting organisms require high-throughput analysis of the motion of a large number of individual subjects. Computer vision techniques offer solutions to specific tracking problems, and allow automated and efficient tracking with minimal human intervention. In this work, we adopt the open active contour model to track the trajectories of moving objects at high density. We add repulsive interactions between open contours to the original model, treat the trajectories as an extrusion in the temporal dimension, and show applications to two tracking problems. The walking behavior of Drosophila is studied at different population density and gender composition. We demonstrate that individual male flies have distinct walking signatures, and that the social interaction between flies in a mixed gender arena is gender specific. We also apply our model to studies of trajectories of gliding Myxococcus xanthus bacteria at high density. We examine the individual gliding behavioral statistics in terms of the gliding speed distribution. Using these two examples at very distinctive spatial scales, we illustrate the use of our algorithm on tracking both short rigid bodies (Drosophila) and long flexible objects (Myxococcus xanthus). Our repulsive active membrane model reaches error rates better than $5\times 10^{-6}$ per fly per second for Drosophila tracking and comparable results for Myxococcus xanthus.
description: 18 pages, 6 figures, 1 table
A Resolution of the Monopole Problem in the R_h=ct Universe
Creators: name: Melia, Fulvio
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Spontaneous symmetry breaking in grand unified theories is thought to have produced an exceedingly large number of magnetic monopoles in the early Universe. In the absence of suppression or annihilation, these very massive particles should be dominating the cosmic energy budget today, but none has ever been found. Inflation was invented in part to dilute their number, thereby rendering their density undetectable by current instruments. Should the inflationary paradigm not survive, however, the ensuing disagreement between theory and observation would constitute a cosmological `monopole problem' and create further tension for any extension to the standard model of particle physics. But as is also true for all horizon problems, a monopole overabundance emerges only in cosmologies with an initial period of deceleration. We show that the alternative Friedmann-Lemaitre-Robertson-Walker cosmology known as the R_h=ct universe completely eliminates all such anomalies rather trivially and naturally, without the need for an inflated expansion. We find that the monopole energy density today would be completely undetectable in R_h=ct. Evidence continues to grow that the zero active mass condition from general relativity ought to be an essential ingredient in LCDM.
description: 18 pages. Accepted for publication in Physics of the Dark Universe
Query Optimization Techniques For Scaling Up To Data Variety
Creators: name: Rohde, Philipp Daniel
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2019
Subjects: subject: Federated Query Processing
subject: Federated Query Engine
subject: Semantic Data Lake
subject: Heterogeneous Data Sources
subject: RDF Molecule Template
subject: Dewey Decimal Classification::000 | Allgemeines, Wissenschaft::000 | Informatik, Wissen, Systeme::004 | Informatik

description: Even though Data Lakes are efficient in terms of data storage, they increase the complexity of query processing; this can lead to expensive query execution. Hence, novel techniques for generating query execution plans are demanded. Those techniques have to be able to exploit the main characteristics of Data Lakes. Ontario is a federated query engine capable of processing queries over heterogeneous data sources. Ontario uses source descriptions based on RDF Molecule Templates, i.e., an abstract description of the properties belonging to the entities in the unified schema of the data in the Data Lake. This thesis proposes new heuristics tailored to the problem of query processing over heterogeneous data sources including heuristics specifically designed for certain data models. The proposed heuristics are integrated into the Ontario query optimizer. Ontario is compared to state-of-the-art RDF query engines in order to study the overhead introduced by considering heterogeneity during query processing. The results of the empirical evaluation suggest that there is no significant overhead when considering heterogeneity. Furthermore, the baseline version of Ontario is compared to two different sets of additional heuristics, i.e., heuristics specifically designed for certain data models and heuristics that do not consider the data model. The analysis of the obtained experimental results shows that source-specific heuristics are able to improve query performance. Ontario optimization techniques are able to generate effective and efficient query plans that can be executed over heterogeneous data sources in a Data Lake.
On semigroups of nonnegative functions and positive operators
Creators: name: Drnovšek, Roman
name: Radjavi, Heydar
Publisher: name: arXiv
Year: 2013
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 20M20, 15B48

description: We give extensions of results on nonnegative matrix semigroups which deduce finiteness or boundedness of such semigroups from the corresponding local properties, e.g., from finiteness or boundedness of values of certain linear functionals applied to them. We also consider more general semigroups of functions.
description: 12 pages