cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Ein neues Verfahren zur Bestimmung der Meßunsicherheit unter Berücksichtigung von Frequenzbereichen und Verteilungsformen
Creators: name: Hildebrandt, Petra
Publisher: name: Hannover : Universität
Year: 1998
Subjects: subject: Measurement
subject: uncertainty
subject: modelling
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: [no abstract]
Mapping dust through emission and absorption in nearby galaxies
Creators: name: Kreckel, K.
name: Groves, B.
name: Schinnerer, E.
name: Johnson, B. D.
name: Aniano, G.
name: Calzetti, D.
name: Croxall, K. V.
name: Draine, B. T.
name: Gordon, K. D.
name: Crocker, A. F.
name: Dale, D. A.
name: Hunt, L. K.
name: Kennicutt, R. C.
name: Meidt, S. E.
name: Smith, J. D. T.
name: Tabatabaei, F. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Dust has long been identified as a barrier to measuring inherent galaxy properties. However, the link between dust and attenuation is not straightforward and depends on both the amount of dust and its distribution. Herschel imaging of nearby galaxies undertaken as part of the KINGFISH project allows us to map the dust as seen in emission with unprecedented sensitivity and ~1 kpc resolution. We present here new optical integral field unit spectroscopy for eight of these galaxies that provides complementary 100-200 pc scale maps of the dust attenuation through observation of the reddening in both the Balmer decrement and the stellar continuum. The stellar continuum reddening, which is systematically less than that observed in the Balmer decrement, shows no clear correlation with the dust, suggesting that the distribution of stellar reddening acts as a poor tracer of the overall dust content. The brightest HII regions are observed to be preferentially located in dusty regions, and we do find a correlation between the Balmer line reddening and the dust mass surface density for which we provide an empirical relation. Some of the high-inclination systems in our sample exhibit high extinction, but we also find evidence that unresolved variations in the dust distribution on scales smaller than 500 pc may contribute to the scatter in this relation. We caution against the use of integrated A_V measures to infer global dust properties.
description: 17 pages, 10 figures, accepted for publication in ApJ
Limits on intermediate-mass black holes in six Galactic globular clusters with integral-field spectroscopy
Creators: name: Lützgendorf, Nora
name: Kissler-Patig, Markus
name: Gebhardt, Karl
name: Baumgardt, Holger
name: Noyola, Eva
name: de Zeeuw, P. Tim
name: Neumayer, Nadine
name: Jalali, Behrang
name: Feldmeier, Anja
Publisher: name: arXiv
Year: 2012
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The formation of supermassive black holes at high redshift still remains a puzzle to astronomers. Their growth becomes reasonable only when starting from a massive seed black hole with mass of the order of 10^2 - 10^5 M_SUN. Intermediate-mass black holes (IMBHs) are therefore an important field of research. Especially the possibility of finding them in the centers of globular clusters has recently drawn attention. The search for IMBHs in the centers of globular clusters could therefore shed light on the process of black-hole formation and cluster evolution. We are investigating six galactic globular clusters for the presence of an IMBH at their centers. Based on their kinematic and photometric properties, we selected the globular clusters NGC 1851, NGC 1904 (M79), NGC 5694, NGC 5824, NGC 6093 (M80) and NGC 6266 (M62). We use integral field spectroscopy in order to obtain the central velocity-dispersion profile of each cluster. We compute the cluster photometric center and the surface brightness profile using HST data. After combining these datasets we compare them to analytic Jeans models. We use varying M/L_V profiles for clusters with enough data points in order to reproduce their kinematic profiles in an optimal way. Finally, we vary the mass of the central black hole and test whether the cluster is better fitted with or without an IMBH. We present the statistical significance, including upper limits, of the black-hole mass for each cluster. NGC 1904 and NGC 6266 provide the highest significance for a black hole. Jeans models in combination with a M/L_V profile obtained from N-body simulations (in the case of NGC 6266) predict a central black hole of M_BH = (3 +- 1) x 10^3 M_SUN for NGC 1904 and M_BH = (2 +- 1) x 10^3 M_SUN for NGC 6266. Furthermore, we discuss the possible influence of dark remnants and mass segregation at the center of the cluster on the detection of an IMBH.
description: 24 pages, 13 figures, Accepted for publication in A&A
Variant N= 1 Supersymmetric Non-Abelian Proca-Stueckelberg Formalism in Four Dimensions
Creators: name: Nishino, Hitoshi
name: Rajpoot, Subhash
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a new (variant) formulation of N=1 supersymmetric compensator mechanism for an arbitrary non-Abelian group in four dimensions. We call this `variant supersymmetric non-Abelian Proca-Stueckelberg formalism'. Our field content is economical, consisting only of the two multiplets: (i) A Non-Abelian vector multiplet (A_μ^I, λ^I, C_{μνρ}{}^I) and (ii) A compensator tensor multiplet (B_{μν}{}^I, χ^I, φ^I). The index I is for the adjoint representation of a non-Abelian gauge group. The C_{μνρ}{}^I is originally an auxiliary field Hodge-dual to the conventional auxiliary field D^I. The φ^I and B_{μν}{}^I are compensator fields absorbed respectively into the longitudinal components of A_μ^I and C_{μνρ}{}^I which become massive. After the absorption, C_{μνρ}{}^I becomes no longer auxiliary, but starts propagating as a massive scalar field. We fix all non-trivial cubic interactions in the total lagrangian, and quadratic interactions in all field equations. The superpartner fermion χ^I acquires a Dirac mass shared with the gaugino λ^I. As an independent confirmation, we give the superspace re-formulation of the component results.
description: 19 pages, no figure
Synchronization theory of microwave induced zero-resistance states
Creators: name: Zhirov, O. V.
name: Chepelianskii, A. D.
name: Shepelyansky, D. L.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We develop the synchronization theory of microwave induced zero-resistance states (ZRS) for two-dimensional electron gas in a magnetic field. In this theory the dissipative effects lead to synchronization of cyclotron phase with driving microwave phase at certain resonant ratios between microwave and cyclotron frequencies. This synchronization produces stabilization of electron transport along edge channels and at the same time it gives suppression of dissipative scattering on local impurities and dissipative conductivity in the bulk, thus creating the ZRS phases at that frequency ratios. The electron dynamics along edge and around circular disk impurity is well described by the Chirikov standard map. The theoretical analysis is based on extensive numerical simulations of classical electron transport in a strongly nonlinear regime. We also discuss the value of activation energy obtained in our model and the experimental signatures that could establish the synchronization origin of ZRS.
description: revtex, 15 pages, 17 figs
Strukturaufklärung des C-19-C-29-Fragmentes von Amycin B sowie von Sibyllimycin
Creators: name: Hoyer, Frank
Publisher: name: Hannover : Universität
Year: 1998
Subjects: subject: 1,3-polyols
subject: hetero-Diels-Alder-reactions
subject: azaindolizidines
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Detaillierte Untersuchung des Stoffübergangs in Blasenströmungen
Creators: name: Paaschen, Tim-Oliver
Publisher: name: Hannover : Universität
Year: 1998
Subjects: subject: Mass transfer
subject: single bubbles
subject: bubble swarms
subject: laser light-sheet technique
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: [no abstract]
Synthesen und absolute Konfigurationen von Piperidinolalkaloiden : Arbeiten zur Darstellung von Epothilon ; chirale [beta]-Hydroxycarbonsäureester als Intermediate in der Naturstoffsynthese
Creators: name: Pahl, Axel
Publisher: name: Hannover : Universität
Year: 1998
Subjects: subject: Piperidinol alkaloids
subject: epothilone
subject: chemoenzymatic synthesis
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Elektrochromes Verhalten von Preußisch Blau in geordnet-mesoporösen leitfähigen Dünnschichtfilmen
Creators: name: Seelandt, Britta
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2011
Subjects: subject: Electrochromism
subject: thin films
subject: mesoporosity
subject: Elektrochromie
subject: Dünnschichtfilme
subject: Mesoporösität
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Betriebliche Maßnahmen zur Optimierung der Leistungsfähigkeit der Bahnstrecken und zur Erhöhung der Reisegeschwindigkeit des Personenverkehrs in China
Creators: name: Shi, Lei
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2011
Subjects: subject: Railway operations
subject: performance
subject: cruising speed
subject: Eisenbahnbetrieb
subject: Leistungsfähigkeit
subject: Reisegeschwindigkeit
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::380 | Handel, Kommunikation, Verkehr

description: [no abstract]
Resolving the optical emission lines of Lya blob 'B1' at z=2.38: another hidden quasar
Creators: name: Overzier, R. A.
name: Nesvadba, N. P. H.
name: Dijkstra, M.
name: Hatch, N. A.
name: Lehnert, M. D.
name: Villar-Martín, M.
name: Wilman, R. J.
name: Zirm, A. W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We have used the SINFONI near-infrared integral field unit on the VLT to resolve the optical emission line structure of one of the brightest (L~1e44 erg/s) and nearest (z=2.38) of all Lya blobs (LABs). The target, known in the literature as object 'B1' (Francis et al. 1996), lies at a redshift where the main optical emission lines are accessible in the observed near-infrared. We detect luminous [OIII]4959,5007A and Ha emission with a spatial extent of at least 32x40 kpc (4"x5"). The dominant optical emission line component shows relatively broad lines (600-800 km/s, FWHM) and line ratios consistent with AGN-photoionization. The new evidence for AGN photoionization, combined with previously detected CIV and luminous, warm infrared emission, suggest that B1 is the site of a hidden quasar. This is confirmed by the fact that [OII] is relatively weak compared to [OIII] (extinction-corrected [OIII]/[OII] of about 3.8), which is indicative of a high, Seyfert-like ionization parameter. From the [OIII] luminosity we infer a bolometric AGN luminosity of ~3e46 erg/s, and further conclude that the obscured AGN may be Compton-thick given existing X-ray limits. The large line widths observed are consistent with clouds moving within the narrow line region of a luminous QSO. The AGN scenario is capable of producing sufficient ionizing photons to power the Lya, even in the presence of dust. By performing a census of similar objects in the literature, we find that virtually all luminous LABs harbor obscured quasars. Based on simple duty-cycle arguments, we conclude that AGN are the main drivers of the Lya in LABs rather than the gravitational heating and subsequent cooling suggested by cold stream models. We also conclude that the empirical relation between LABs and overdense environments at high redshift must be due to a more fundamental correlation between AGN (or massive galaxies) and environment.
description: ApJ, Accepted (12 pages, 6 figures, 2 tables)
Entwicklung eines Modells zur Vorhersage stationärer Transitionsmechanismen in Niederdruckturbinen unter dem Einsatz von skalenauflösenden Simulationen
Creators: name: Müller-Schindewolffs, Christoph
Publisher: name: Hannover : Institut für Turbomaschinen und Fluid-Dynamik
Year: 2022
Subjects: subject: Transition
subject: Turbine
subject: Scale Resolving Simulation
subject: Reynolds-Averaged Navier-Stokes
subject: Modeling
subject: Skalenauflösende Simulation
subject: Modellierung
subject: Dewey Decimal Classification::600 | Technik

description: Steady RANS simulations form the backbone of the aerodynamic turbomachinery design tool chain. They combine a fast response with the ability to describe three-dimensional geometries. However, they are based on approximations through modeling approaches. This is especially relevant for predicting boundary layer transition correctly which has a high impact on low-pressure turbine efficiency. Due to the high standard of modern low-pressure turbine efficiency, it is important to resolve complex three-dimensional geometries including small features accurately. This includes the appropriate transition prediction on airfoils and becomes increasingly relevant for endwalls as well. The transition prediction on these three-dimensional geometries requires locally formulated transition models, such as the γ-Reθ model. These models are required to be robust but also sensitive to environmental impacts, particularly in the two-dimensional mean flow. Within the present work, potentials of the established γ-Reθ model are presented and transferred to a reformulation of the model. This includes the consideration of further influencing parameters on the transition process and a more detailed modeling of transition phases. However, the essential improvement of the new model variant, called MSC2020, is a more precise determination of the pressure gradient parameter. This requires fundamental reformulation of model equations on the one hand, but it allows acquiring a more sensitively calibrated model that shows dynamic behavior with increased accuracy on the other hand. The model development is accompanied by an iLES study of the MTU-T161 low-pressure turbine cascade. Characteristic transitional structures are analyzed and brought into relation to the transition modeling by the MSC2020 model. As it turns out, the large amounts of turbulent kinetic energy predicted by the iLES do not agree with the modeled turbulence predicted by two-equation models. Only the turlulent energy resulting from the three-dimensional breakdown of the Kelvin-Helmholtz Instability can be related to modeled turbulence. The elaborated and calibrated model predicts transition on a variety of turbine and compressor cascades precisely which results in a significant improvement in comparison to the γ-Reθ reference model. This is also valid for turbine cascades that are operated far-off design point, where the model is robust and reliable. Besides the intention to improve the transition prediction within the two-dimensional flow regions, the loss prediction driven by secondary flows close to the endwalls of the MTU-T161 cascade is improved as well.
Vortex dynamics as a function of field orientation in BaFe1.9Ni0.1As2
Creators: name: Salem-Sugui, S.
name: Ghivelder, L.
name: Alvarenga, A. D.
name: Cohen, L. F.
name: Luo, Huiquian
name: Lu, Xingye
Publisher: name: arXiv
Year: 2012
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Vortex dynamics in a multiband anisotropic superconducting such as the Fe based superconductors, is interesting and potentially important for applications. In this study we examine flux-creep data for fields along the second magnetization peak observed in M(H) curves of BaFe$_{1.9}$Ni$_{0.1}$As$_2$ for H//c-axis, H//ab$-planes and H forming a 45$^o$ angle with ab-planes. We find that the M-H loops taken from the different field directions can be collapsed onto a single universal curve at all temperatures with a simple scaling factor equivalent to the superconducting anisotropy, showing not only that the vortex pinning is isotropic, three dimensional and most likely related to point like defects. The resulting critical currents however, taken from the Bean model appears to show enhanced low field pinning for H//c. The features in the vortex- dynamics also differ in different field orientations and show no direct correlation with the second magnetization peak Hp as is the case with a direct crossover in pinning regimes. Isofield plots of the scaled activation energy obtained from flux-creep data is found to be a smooth function of temperature as the Hp(T) line is crossed consistent with a single type of pinning regime operating at this field, independent of field orientation. The functional form of the Hp(T) lines in the resulting phase diagrams also support this view.
description: 6 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1209.1594
Gamma-Ray Burst Science in the Era of the Cherenkov Telescope Array
Creators: name: Inoue, Susumu
name: Granot, Jonathan
name: O'Brien, Paul T.
name: Asano, Katsuaki
name: Bouvier, Aurelien
name: Carosi, Alessandro
name: Connaughton, Valerie
name: Garczarczyk, Markus
name: Gilmore, Rudy
name: Hinton, Jim
name: Inoue, Yoshiyuki
name: Ioka, Kunihito
name: Kakuwa, Jun
name: Markoff, Sera
name: Murase, Kohta
name: Osborne, Julian P.
name: Otte, A. Nepomuk
name: Starling, Rhaana
name: Tajima, Hiroyasu
name: Teshima, Masahiro
name: Toma, Kenji
name: Wagner, Stefan
name: Wijers, Ralph A. M. J.
name: Williams, David A.
name: Yamamoto, Tokonatsu
name: Yamazaki, Ryo
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We outline the science prospects for gamma-ray bursts (GRBs) with the Cherenkov Telescope Array (CTA), the next-generation ground-based gamma-ray observatory operating at energies above few tens of GeV. With its low energy threshold, large effective area and rapid slewing capabilities, CTA will be able to measure the spectra and variability of GRBs at multi-GeV energies with unprecedented photon statistics, and thereby break new ground in elucidating the physics of GRBs, which is still poorly understood. Such measurements will also provide crucial diagnostics of ultra-high-energy cosmic ray and neutrino production in GRBs, advance observational cosmology by probing the high-redshift extragalactic background light and intergalactic magnetic fields, and contribute to fundamental physics by testing Lorentz invariance violation with high precision. Aiming to quantify these goals, we present some simulated observations of GRB spectra and light curves, together with estimates of their detection rates with CTA. Although the expected detection rate is modest, of order a few GRBs per year, hundreds or more high-energy photons per burst may be attainable once they are detected. We also address various issues related to following up alerts from satellites and other facilities with CTA, as well as follow-up observations at other wavelengths. The possibility of discovering and observing GRBs from their onset including short GRBs during a wide-field survey mode is also briefly discussed.
description: Astroparticle Physics, in press, for the special issue on "Physics with the Cherenkov Telescope Array"; 28 pages, 19 figures; replaced with cosmetically revised version
Simplicity of partial skew group rings of abelian groups
Creators: name: Gonçalves, Daniel
Publisher: name: arXiv
Year: 2013
Subjects: subject: Rings and Algebras (math.RA)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics

description: Let $\A$ be a ring with local units, $\E$ a set of local units for $\A$, $\G$ an abelian group and $α$ a partial action of $\G$ by ideals of $\A$ that contain local units and such that the partial skew group ring $\A\star_α \G$ is associative. We show that $\A\star_α \G$ is simple if and only if $\A$ is $\G$-simple and the center of the corner $eδ_0 (\A\star_α \G) e δ_0$ is a field for all $e\in \E$. We apply the result to characterize simplicity of partial skew group rings in two cases, namely for partial skew group rings arising from partial actions by clopen subsets of a compact set and partial actions on the set level.
Esrium Data Platform
Creators: name: Csepinszky, András
Publisher: name: Zenodo
Year: 2021
Subjects: metadata
spatial database
road damage

description: Data Management Platform (DMP) Layer to store road wear map features and road wear predictions with metadata Aggregates different types of road wear hotspots as spatial features Implemented as spatial database with time series support Provides management, validation and visualization modules Provides interface for uploading and querying data
title: »Vergiß den Ball und spiel' weiter - Das Bild des Kindes in der zeitgenössischen Kunst«. Ausstellung in der Kunsthalle Nürnberg vom 21. Oktober 1999 bis 9. Januar 2000
Creators: name: Unterdörfer, Michaela
Publisher: name: University Library Heidelberg
Year: 2016

description: [nicht vorhanden / not available]
Functional methods for correlation functions of integrable face and anyon models
Creators: name: Westerfeld, Daniel
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2022
Subjects: subject: correlation functions
subject: face models
subject: anyons
subject: density matrices
subject: functional equations
subject: Korrelationsfunktionen
subject: Face-Modelle
subject: Anyonen
subject: Dichtematrizen
subject: Funktionalgleichungen
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: The computation of correlation functions in models of statistical mechanics is the key to comparing theoretical results with actual measurements. In the context of integrable lattice models there exists a rich literature on correlators in vertex models and related quantum-spin chains. Less is known for integrable face models and their related anyon chains. Therefore, we define generalised transfer matrices allowing for a solution of the `inverse problem', i.e.\ we express local operators by means of objects from the Yang-Baxter algebra. This motivates the study of reduced density matrices which contain the information of all correlation functions. Instead of directly calculating them, we show that they fulfil a set of functional equations. We use these equations to study density matrices in (R)SOS models and their related anyon chains. In particular, we find integral representations for the two and three-point functions of the $r=4$ RSOS model and calculate those quantities for the $r=5$ model in the thermodynamic limit. In addition we observe a factorisation of the three-point functions into two-point functions and propose an efficient algorithm to factorise reduced density matrices for generic models. In the last section we study density matrices for the $SO(5)_2$ face models. We examine the structure of the two-site reduced density matrices and simplify them for certain topological sectors. Since there exist different inequivalent sets of Boltzmann weights, the latter is done for each choice leading to sets of discrete functional equations.
Replication Package for conference paper titled "From Reinvention to Reuse: An Empirical Example Study On Technical Debt Dataset", which was published in PROFES'24.
Creators: name: Rantala, Leevi
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 461202
subject: Empirical software engineering

description: This dataset contains information to replicate the results from paper: "From Reinvention to Reuse: An Empirical Example Study On Technical Debt Dataset".
The files include README-file, which explain the whole process on how to reproduce the results, including links to Python and R repositories used in the process.
Also included is the final dataset created in the process with 31 different variables. See data_description.txt for further details.
Role of electron-electron interference in ultrafast time-resolved imaging of electronic wavepackets
Creators: name: Dixit, Gopal
name: Santra, Robin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Ultrafast time-resolved x-ray scattering is an emerging approach to image the dynamical evolution of the electronic charge distribution during complex chemical and biological processes in real-space and real-time. Recently, the differences between semiclassical and quantum-electrodynamical (QED) theory of light-matter interaction for scattering of ultrashort x-ray pulses from the electronic wavepacket were formally demonstrated and visually illustrated by scattering patterns calculated for an electronic wavepacket in atomic hydrogen [Proc. Natl. Acad. Sci. U.S.A., {\bf 109}, 11636 (2012)]. In this work, we present a detailed analysis of time-resolved x-ray scattering from a sample containing a mixture of non-stationary and stationary electrons within both the theories. In a many-electron system, the role of scattering interference between a non-stationary and several stationary electrons to the total scattering signal is investigated. In general, QED and semiclassical theory provide different results for the contribution from the scattering interference, which depends on the energy resolution of the detector and the x-ray pulse duration. The present findings are demonstrated by means of a numerical example of x-ray TRI for an electronic wavepacket in helium. It is shown that the time-dependent scattering interference vanishes within semiclassical theory and the corresponding patterns are dominated by the scattering contribution from the time-independent interference, whereas the time-dependent scattering interference contribution does not vanish in the QED theory and the patterns are dominated by the scattering contribution from the non-stationary electron scattering.
description: 20 pages, 3 figures, to be published in J. Chem. Phys. (2013)
Accurate Long-Term Multiple People Tracking Using Video and Body-Worn IMUs
Creators: name: Henschel, Roberto
name: Marcard, Timo Von
name: Rosenhahn, Bode
Publisher: name: New York, NY : IEEE
Year: 2020
Subjects: subject: Inertial navigation systems
subject: Inertial measurement unit
subject: Motion information
subject: Multiple people tracking
subject: Tracking accuracy
subject: Tracking sequence
subject: Tracking solutions
subject: Video information
subject: Visual occlusions
subject: Wearable sensors
subject: graph labeling
subject: human motion analysis
subject: IMU
subject: sensor fusion
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau
subject: Dewey Decimal Classification::000 | Allgemeines, Wissenschaft::000 | Informatik, Wissen, Systeme::004 | Informatik

description: Most modern approaches for video-based multiple people tracking rely on human appearance to exploit similarities between person detections. Consequently, tracking accuracy degrades if this kind of information is not discriminative or if people change apparel. In contrast, we present a method to fuse video information with additional motion signals from body-worn inertial measurement units (IMUs). In particular, we propose a neural network to relate person detections with IMU orientations, and formulate a graph labeling problem to obtain a tracking solution that is globally consistent with the video and inertial recordings. The fusion of visual and inertial cues provides several advantages. The association of detection boxes in the video and IMU devices is based on motion, which is independent of a person's outward appearance. Furthermore, inertial sensors provide motion information irrespective of visual occlusions. Hence, once detections in the video are associated with an IMU device, intermediate positions can be reconstructed from corresponding inertial sensor data, which would be unstable using video only. Since no dataset exists for this new setting, we release a dataset of challenging tracking sequences, containing video and IMU recordings together with ground-truth annotations. We evaluate our approach on our new dataset, achieving an average IDF1 score of 91.2%. The proposed method is applicable to any situation that allows one to equip people with inertial sensors. ¬© 1992-2012 IEEE.
Are Product Owners communicators? A multi-method research approach to provide a more comprehensive picture of Product Owners in practice
Creators: name: Unger-Windeler, Carolin
name: Klünder, Jil Ann-Christin
name: Reuscher, Timothy
name: Schneider, Kurt
Publisher: name: New York, NY [u.a.] : Wiley-Blackwell
Year: 2020
Subjects: subject: Mapping
subject: Communication activities
subject: Development environment
subject: Mapping studies
subject: Research approach
subject: Research results
subject: Shadowing techniques
subject: Software development process
subject: Systematic mapping studies
subject: Software design
subject: agile software development
subject: communication
subject: On-Site Customer
subject: Product Owner
subject: Scrum
subject: systematic mapping study
subject: XP
subject: Dewey Decimal Classification::000 | Allgemeines, Wissenschaft::000 | Informatik, Wissen, Systeme::004 | Informatik

description: Product Owners have an important role in the agile and hybrid software development process. While this role is supposed to maximize the value of a product, there seem to be several scattered results on how they achieve this, as well as what actually constitutes this role in practice. To consolidate current research results and to further analyze the key attribute of Product Owners, we conducted a multi-method research approach spanning a systematic mapping study and a consecutive case study in a hybrid development environment. The results of the mapping study states that Product Owners are communicators. We further investigated on this and used the shadowing technique to observe three Product Owners' communication activities. The results support that statement, as the gained data reveal that Product Owners spend 65% of their time in meetings. But rather than just providing the team with the necessary requirements for the product under development, Product Owners need this time to synchronize and align their work, streamline the agile process of large-scale Scrum, discuss team-based topics, and to solve upcoming issues addressed by the team. These results contribute to draw a more comprehensive picture of the important but yet complex role of Product Owners in practice. ¬© 2020 John Wiley & Sons, Ltd.
Knowledge-based process planning for economical re-scheduling in production control
Creators: name: Denkena, Berend
name: Dittrich, Marc-Andre
name: Stamm, Siebo Claas
name: Prasanthan, Vannila
Publisher: name: Amsterdam : Elsevier B.V.
Year: 2019
Subjects: subject: Adaptive manufacturing
subject: Knowledge based system
subject: Machine learning
subject: Scheduling
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung

description: Nowadays, high flexibility and responsiveness towards capacity adjustments are key to successful production planning and control in manufacturing. Moreover, many companies – especially job shops – have to deal with short-term re-scheduling. This article presents an approach for knowledge-based process planning to enable an economic evaluation of re-scheduling in the manufacturing system. For that purpose, the manufacturing costs for each workpiece are calculated based on determined parameter sets and process time under consideration of potential capacity adjustments. The knowledge-based process planning is necessary to derive reliable process times for re-scheduling and cost calculating. Hence, a pre-study is carried out to define flexible machine learning algorithms for knowledge-based process planning. © 2019 The Authors. Published by Elsevier Ltd.
Scattering of Cold Atom Coherences by Hot Atoms: Frequency Shifts from Background Gas Collisions
Creators: name: Gibble, Kurt
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Frequency shifts from background gas collisions currently contribute significantly to the inaccuracy of atomic clocks. Because nearly all collisions with room-temperature background gases that transfer momentum eject the cold atoms from the clock, the interference between the scattered and unscattered waves in the forward direction dominates these frequency shifts. We show they are ~10 times smaller than in room-temperature clocks and that van der Waals interactions produce the cold-atom background-gas shift. General considerations allow the loss of Ramsey fringe amplitude to bound this frequency shift.
Compensation of part distortion in process design for re-contouring processes
Creators: name: Böß, Volker
name: Rust, Felix
name: Dittrich, Marc-Andre
name: Denkena, Berend
Publisher: name: Amsterdam : Elsevier B.V.
Year: 2019
Subjects: subject: Adaptive manufacturing
subject: Blade repair
subject: Milling
subject: Part distortion
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung

description: The repair of compressor blades requires a precise coordination of the material deposit and the subsequent re-contouring process. Since re-contouring is the last step in the process chain, it is a crucial stage for the final part quality and shape. Therefore, machining-induced part distortions must be considered in process design. This paper introduces a method for the simulation-based compensation of part distortions. The method combines process planning and evaluation by means of a geometric simulation. In order to validate the approach, milling experiments are carried out. A subsequent measurement of the part geometry shows that the part distortion can be reduced by up to 21% using the presented approach. © 2019 The Authors. Published by Elsevier Ltd.
Optimization of complex cutting tools using a multi-dexel based material removal simulation
Creators: name: Denkena, Berend
name: Grove, T.
name: Pape, O.
Publisher: name: Amsterdam : Elsevier B.V.
Year: 2019
Subjects: subject: Geometric modeling
subject: Optimization
subject: Simulaton
subject: Geometry
subject: Machining centers
subject: Milling (machining)
subject: Milling cutters
subject: Turning
subject: Advanced process
subject: Discretizations
subject: Indexable inserts
subject: Material removal
subject: Serrated end mills
subject: Turning operations
subject: Cutting tools
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung

description: Multi-dexel based material removal simulations provide a fast and flexible way to compute process forces and tool deflections for milling and turning operations. This allows an advanced process planning including detection of collisions for complex toolpaths. However, using dexel simulations for designing cutting tools has rarely been investigated. Especially the position of individual cutting edges is not considered, because current approaches only subtract the sweep volume of the tool envelop instead of the rake face. This paper presents a new method to design cutting tools using material removal simulations and a detailed tool geometry representation. The discretization of the tool allows an efficient calculation of the engagement conditions of individual cutting edges. The method is used to optimize novel porcupine milling cutters with round indexeble inserts, which produces a geometry analogous to serrated end mills. Based on the calculated forces, the positions of individual indexable inserts are adjusted to minimize the maximum radial force. An optimum has been found that reduces radial force by 12% compared to conventional porcupine milling cutters with squared inserts. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations
Physics of a partially ionized gas relevant to galaxy formation simulations -- the ionization potential energy reservoir
Creators: name: Vandenbroucke, Bert
name: De Rijcke, Sven
name: Schroyen, Joeri
name: Jachowicz, Natalie
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Simulation codes for galaxy formation and evolution take on board as many physical processes as possible beyond the standard gravitational and hydrodynamical physics. Most of this extra physics takes place below the resolution level of the simulations and is added in a sub-grid fashion. However, these sub-grid processes affect the macroscopic hydrodynamical properties of the gas and thus couple to the on-grid physics that is explicitly integrated during the simulation. In this paper, we focus on the link between partial ionization and the hydrodynamical equations. We show that the energy stored in ions and free electrons constitutes a potential energy term which breaks the linear dependence of the internal energy on temperature. Correctly taking into account ionization hence requires modifying both the equation of state and the energy-temperature relation. We implemented these changes in the cosmological simulation code Gadget2. As an example of the effects of these changes, we study the propagation of Sedov-Taylor shock waves through an ionizing medium. This serves as a proxy for the absorption of supernova feedback energy by the interstellar medium. Depending on the density and temperature of the surrounding gas, we find that up to 50% of the feedback energy is spent ionizing the gas rather than heating it. Thus, it can be expected that properly taking into account ionization effects in galaxy evolution simulations will drastically reduce the effects of thermal feedback. To the best of our knowledge, this potential energy term is not used in current simulations of galaxy formation and evolution.
description: 8 pages, 4 figures. Accepted for publication in ApJ
Coupled Transport Effects in Solid Oxide Fuel Cell Modeling
Creators: name: Gedik, Aydan
name: Lubos, Nico
name: Kabelac, Stephan
Publisher: name: Basel : MDPI
Year: 2022
Subjects: subject: Dusty-Gas model (DGM)
subject: Entropy production
subject: Exergy efficiency
subject: Non-equilibrium thermodynamics (NET)
subject: Solid oxide fuel cell (SOFC)
subject: Soret effect
subject: Thermal diffusion
subject: Dewey Decimal Classification::500 | Naturwissenschaften::510 | Mathematik

description: With its outstanding performance characteristics, the SOFC represents a promising technology for integration into the current energy supply system. For cell development and optimization, a reliable quantitative description of the transport mechanisms and the resulting losses are relevant. The local transport processes are calculated by a 1D model based on the non-equilibrium thermodynamics (NET). The focus of this study is the mass transport in the gas diffusion layers (GDL), which was described as simplified by Fick’s law in a previously developed model. This is first replaced by the Dusty-Gas model (DGM) and then by the thermal diffusion (Soret effect) approach. The validation of the model was performed by measuring U, j-characteristics resulting in a maximum deviation of experimental to simulated cell voltage to up to 0.93%. It is shown that, under the prevailing temperature, gradients the Soret effect can be neglected, but the extension to the DGM has to be considered. The temperature and heat flow curves illustrate the relevance of the Peltier effects. At T = 1123.15 K and j = 8000 A/m2, 64.44% of the total losses occur in the electrolyte. The exergetic efficiency for this operating point is 0.42. Since lower entropy production rates can be assumed in the GDL, the primary need is to investigate alternative electrolyte materials. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Optical polarization anisotropy, intrinsic Stark effect and Coulomb effects on the lasing characteristics of [0001]-oriented GaN/Al0.3Ga0.7N quantum wells
Creators: name: Lokot, L. O.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a theoretical investigation of space separated electron and hole distributions, which consists in the self-consistent solving of the Schrodinger equations for electrons and holes and the Poisson equation. The results are illustrated for the GaN/Al0.3Ga0.7N quantum well. The optical gain spectrum in a [0001]-oriented GaN/Al0.3Ga0.7N quantum well in the ultraviolet region is calculated. It is found that both the matrix elements of optical transitions from the heavy hole band and the optical gain spectrum have only the strict x (or y) light polarization. We present studies of the influence of the confinement of wave functions on the optical gain which implicitly depends on the built-in electric field calculated to be 2.3 MV/cm. Whereas the structures with narrow well widths exhibit the usual development of the light gain maximum almost without shifting the spectral region, a significant blueshift of the gain maximum is found with increase in the plasma density for wider quantum wells. This blueshift is ascribed to the interplay between the screening of a strain-induced piezoelectric field and the bandstructure. A large Sommerfeld or Coulomb enhancement is present in the quantum well.
description: 11 pages, 6 figures
Bose-Einstein Condensation versus Dicke-Hepp-Lieb Transition in an Optical Cavity
Creators: name: Piazza, Francesco
name: Strack, Philipp
name: Zwerger, Wilhelm
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We provide an exact solution for the interplay between Bose-Einstein condensation and the Dicke-Hepp-Lieb self-organization transition of an ideal Bose gas trapped inside a single-mode optical cavity and subject to a transverse laser drive. Based on an effective action approach, we determine the full phase diagram at arbitrary temperature, which features a bi-critical point where the transitions cross. We calculate the dynamically generated band structure of the atoms and the associated supression of the critical temperature for Bose-Einstein condensation in the phase with a spontaneous periodic density modulation. Moreover, we determine the evolution of the polariton spectrum due to the coupling of the cavity photons and the atomic field near the self-organization transition, which is quite different above or below the Bose-Einstein condensation temperature. At low temperatures, the critical value of the Dicke-Hepp-Lieb transition decreases with temperature and thus thermal fluctuations can enhance the tendency to a periodic arrangement of the atoms.
description: 18 pages, 12 figures
The applicability of the standard DIN EN ISO 3690 for the analysis of diffusible hydrogen content in underwater wet welding
Creators: name: Klett, Jan
name: Wolf, Thomas
name: Maier, Hans Jürgen
name: Hassel, Thomas
Publisher: name: Basel : MDPI AG
Year: 2020
Subjects: subject: AWS A4.3
subject: Diffusible hydrogen
subject: DIN EN ISO 3690
subject: JIS Z 3113
subject: SMAW
subject: Underwater wet welding
subject: Cleaning
subject: Gas metal arc welding
subject: Hydrogen
subject: ISO Standards
subject: Metal analysis
subject: Welding codes
subject: Cleaning process
subject: European Standards
subject: Hydrogen concentration
subject: Number of samples
subject: Shielded metal arc welding
subject: Wet underwater welding
subject: Underwater welding
subject: Dewey Decimal Classification::600 | Technik

description: The European standard ISO 3690 regulates the measurement of diffusible hydrogen in arc-welded metal. It was designed for different welding methods performed in dry atmosphere (20% humidity). Some details of the standard are not applicable for wet underwater welding. The objective of this study was to extend the applicability of DIN EN ISO 3690:2018-12 to underwater wet-shielded metal arc welding (SMAW). Four different aspects regulated within the standard were accounted for: (1) sample dimensions and number of samples taken simultaneously; (2) time limitations defined by the standard regarding the welding and the cleaning process; (3) time, temperature, and method defined for analysis of the diffusible hydrogen content; (4) normalization of the hydrogen concentration measured. Underwater wet welding was performed using an automated, arc voltage-controlled welding machine. The results are discussed in light of standard DIN EN ISO 3690, and recommendations are provided for the analysis of diffusible hydrogen content upon underwater wet welding. © 2020 by the authors.
Supplementary materials to World Mycotoxin Journal: Stakeholder assessment for mycotoxin analysis: exploring the demand along the European food supply chain
Creators: name: Csenki, E.
name: Mikulás, V.
name: Freitag, S.
name: Fomina, P.
name: Ruggeri, F.S.
name: Femenias, A.
name: Bosman, A.J.
name: Smirnova, M.
name: Salentijn, G.
name: Mizaikoff, B.
name: Krska, R.
name: Scholderer, J.
name: Kohler, A.
name: Kasza, G.
Publisher: name: Brill Online
Year: 2023
Subjects: classificationCode: 300605
subject: Food safety, traceability, certification and authenticity

description: Mycotoxins are amongst the most prevalent food contaminants leading to serious health implications for humans and animals. Limiting exposure to them within the population remains a pressing food safety challenge. Prevention and timely detection are crucial for minimising mycotoxin contamination in food and feed. Therefore easy-to-use, rapid, eco-friendly and low-cost screening methods are increasingly implemented. Early-stage end-user engagement in the technological development process aids and guides the research towards increased societal impact. To investigate these end-user needs, the limitations of the currently used methods and the expectations towards a novel approach were mapped among stakeholders in a comprehensive survey. Stakeholders along the food supply chain (agricultural, food processing, retail, food safety and control, laboratories) were identified in five European countries and contacted. A total of 63 participants completed the survey, which was followed-up by an interview. The results of the survey revealed that different end-user groups have different priorities. Important limiting factors for agricultural, processing and retail stakeholders of the current methodologies include the complexity of sample preparation, high cost and time-to-results. Complementing the accredited laboratory tests with a pre-screening device would be especially interesting for agricultural producers (87.5% of the participants are interested) and food processors (80%), since there is an increasing demand for on-site detection of contamination. On the other hand, food control authorities and commercial laboratories indicated higher priority towards low quantification limits and multi-compound methods. The time to get the results was found to be more important than the testing cost (important aspect for 74.6 versus 66.7%). Overall, the findings of this study are critical input for end-user-targeted development of novel mycotoxin detection platforms.