cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Immersive virtual patient simulation compared with traditional education for clinical reasoning: a pilot randomised controlled study
Creators: name: Bonnin, Claire
name: Pejoan, Dominique
name: Ranvial, Eric
name: Marchat, Méryl
name: Andrieux, Nicolas
name: Fourcade, Laurent
name: Perrochon, Anaick
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Medicine
subject: Neuroscience
subject: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine
classificationCode: 69999
subject: Biological Sciences not elsewhere classified
classificationCode: 80699
subject: Information Systems not elsewhere classified
subject: Science Policy

description: Immersive virtual patient simulation could help medical students in clinical reasoning, but there is a lack of literature on the effectiveness of this method in healthcare learning. A pilot randomised controlled study compared performance (exam score) on a clinical case in immersive virtual simulation to a text for physiotherapy students. In the experimental group, the clinical case was presented by an immersive 360° video that students watched with a standalone headset, whereas the control group used the text only. A survey investigated students’ perceptions of the clinical case, their experience of virtual reality, and sense of presence. Twenty-three students in immersive virtual reality had a significantly lower total score than 25 students with a text. This difference appeared in the assessment part of a clinical case. More precisely, it concerned patient history (including a few other elements of assessment and bio-psycho-social factors, p = 0.007). Satisfaction and motivation were strong in the experimental group. In conclusion, the performance was higher in text than in virtual reality situations. Nevertheless, immersive virtual patient simulation remains an interesting tool could train novices to follow history-taking skills of a new patient, as similar to a real-life situation.
Neutrino-tagged jets at the Electron-Ion Collider
Creators: name: Arratia, Miguel
name: Kang, Zhong-Bo
name: Paul, Sebouh J.
name: Prokudin, Alexei
name: Ringer, Felix
name: Zhao, Fanyi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We explore the potential of jet observables in charged-current deep-inelastic scattering (CC DIS) events at the future Electron-Ion Collider (EIC). Tagging jets with a recoiling neutrino, which can be identified by the event's missing transverse momentum, will allow for flavor-sensitive measurements of Transverse Momentum Dependent parton distribution functions (TMDs). We present the first predictions for transverse-spin asymmetries in azimuthal neutrino-jet correlations and hadron-in-jet measurements. We study the kinematic reach and the precision of these measurements and explore their feasibility using parameterized detector simulations. We conclude that jet production in CC DIS, while challenging in terms of luminosity requirements, will complement the EIC experimental program to study the three-dimensional structure of the nucleon encoded in TMDs.
description: 14 pages, 10 figures
Three-observer Bell inequality violation on a two-qubit entangled state
Creators: name: Schiavon, Matteo
name: Calderaro, Luca
name: Pittaluga, Mirko
name: Vallone, Giuseppe
name: Villoresi, Paolo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Bipartite Bell inequalities can be simultaneously violated by two different pairs of observers when weak measurements and signaling is employed. Here we experimentally demonstrate the violation of two simultaneous CHSH inequalities by exploiting a two-photon polarization maximally entangled state. Our results demonstrate that large double violation is experimentally achievable. Our demonstration may have impact for Quantum Key Distribution or certification of Quantum Random Number generators based on weak measurements.
description: Revtex, 5 pages + appendix
The Mass of the Black Hole in NGC 5273 from Stellar Dynamical Modeling
Creators: name: Merrell, Katie A.
name: Vasiliev, Eugene
name: Bentz, Misty C.
name: Valluri, Monica
name: Onken, Christopher A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a new constraint on the mass of the black hole in the active S0 galaxy NGC 5273. Due to the proximity of the galaxy at $16.6 \pm 2.1$ Mpc, we were able to resolve and extract the bulk motions of stars near the central black hole using AO-assisted observations with Gemini NIFS, as well as constrain the large-scale kinematics using re-reduced archival SAURON spectroscopy. High resolution HST imaging allowed us to generate a surface brightness decomposition, determine approximate mass-to-light ratios for the bulge and disk, and obtain an estimate for the disk inclination. We constructed an extensive library of dynamical models using the Schwarzschild orbit-superposition code FORSTAND, exploring a range of disk and bulge shapes, halo masses, etc. We determined a black hole mass of $M_{\bullet} = [0.5 - 2] \times 10^{7}$ $M_{\odot}$, where the low side of the range is in agreement with the reverberation mapping measurement of $M_{\bullet} = [4.7 \pm 1.6] \times 10^{6}$ $M_{\odot}$. NGC 5273 is one of only a small number of nearby galaxies hosting broad-lined AGN, allowing crucial comparison of the black hole masses derived from different mass measurement techniques.
description: 20 pages, 11 figures, 3 tables; submitted to ApJ
Spectral energy distribution simulations of a possible ring structure around the young, red brown dwarf G196-3B
Creators: name: Zakhozhay, Olga V.
name: Osorio, María Rosa Zapatero
name: Béjar, Víctor J. S.
name: Boehler, Yann
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The origin of the very red optical and infrared colours of intermediate-age ($\sim$10 - 500 Myr) L-type dwarfs remains unknown. It has been suggested that low-gravity atmospheres containing large amounts of dust may account for the observed reddish nature. We explored an alternative scenario by simulating protoplanetary and debris discs around G196-3B, which is an L3 young brown dwarf with a mass of $\sim 15$ $M_{\rm Jup}$ and an age in the interval 20 - 300 Myr. The best-fit solution to G196-3B's photometric spectral energy distribution from optical wavelengths through 24 $μ$m corresponds to the combination of an unreddened L3 atmosphere ($T_{\rm eff} \approx 1870$~K) and a warm ($\approx$ 1280 K), narrow ($\approx$ 0.07 - 0.11 R$_{\odot}$) debris disc located at very close distances ($\approx$ 0.12 - 0.20 R$_{\odot}$) from the central brown dwarf. This putative, optically thick, dusty belt, whose presence is compatible with the relatively young system age, would have a mass $\ge 7\times 10^{-10}$ M$_{\oplus}$ comprised of sub-micron/micron characteristic dusty particles with temperatures close to the sublimation threshold of silicates. Considering the derived global properties of the belt and the disc-to-brown dwarf mass ratio, the dusty ring around G196-3B may resemble the rings of Neptune and Jupiter, except for its high temperature and thick vertical height ($\approx 6 \times 10^3$ km). Our inferred debris disc model is able to reproduce G196-3B's spectral energy distribution to a satisfactory level of achievement.
description: 12 pages, 7 figures, 4 tables, accepted for publication in MNRAS
title: Προσομοίωση πλημμυρικού κύματος έπειτα από ενδεχόμενη θραύση του φράγματος Μαραθώνα
title: Simulating the flood wave created after a hypothetical Marathon dam failure
titleType: AlternativeTitle
Creators: name: Φλώρος, Γεώργιος
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Πλημμύρες
Θραύση φράγματος
Φράγμα
Προσομοίωση
QGIS
HEC-HMS
Μαραθώνας

description: Σε αυτή τη διπλωματική εργασία γίνεται η προσομοίωση της διόδευσης του πλημμυρικού κύματος που θα σχηματιστεί έπειτα από ενδεχόμενη θραύση του φράγματος Μαραθώνα, στην κατάντη περιοχή, ενώ θα διερευνηθούν και οι επιπτώσεις της εν λόγω πλημμύρας. Για την προσομοίωση θα χρησιμοποιηθεί το υδροδυναμικό λογισμικό που βασίζεται στις Εξισώσεις Αβαθών Υδάτων, HEC-RAS
Coherent population trapping in a Raman atom interferometer
Creators: name: Cheng, Bing
name: Gillot, Pierre
name: Merlet, Sébastien
name: Santos, Franck Pereira dos
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We investigate the effect of coherent population trapping (CPT) in an atom inter-ferometer gravimeter based on the use of stimulated Raman transitions. We find that CPT leads to significant phase shifts, of order of a few mrad, which may compromise the accuracy of inertial measurements. We show that this effect is rejected by the k-reversal technique, which consists in averaging inertial measurements performed with two opposite orientations of the Raman wavevector k, provided that internal states at the input of the interferometer are kept identical for both configurations.
On emergent conformal symmetry near the photon ring
Creators: name: Chen, Bin
name: Hou, Yehui
name: Hu, Zezhou
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this note we revisit the emergent conformal symmetry in the near-ring region of warped spacetime. In particular, we propose a novel construction of the emergent near-ring $sl(2,R)_{\text{QNM}}$ symmetry. We show that each eikonal QNM family falls into one highest-weight representation of this algebra, and $sl(2,R)_{\text{QNM}}$ can be related to the near-ring isometry group $sl(2,R)_{\text{ISO}}$ in a simple way. Furthermore we find that the coherent state space of $sl(2,R)_{\text{QNM}}$ can be identified with the phase space of the photon ring.
description: 15 pages, minor revisions; Presentation improved, published version
A quasi-periodic modulation of the iron line centroid energy in the black hole binary H 1743-322
Creators: name: Ingram, Adam
name: van der Klis, Michiel
name: Middleton, Matthew
name: Done, Chris
name: Altamirano, Diego
name: Heil, Lucy
name: Uttley, Phil
name: Axelsson, Magnus
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Accreting stellar-mass black holes often show a `Type-C' quasi-periodic oscillation (QPO) in their X-ray flux, and an iron emission line in their X-ray spectrum. The iron line is generated through continuum photons reflecting off the accretion disk, and its shape is distorted by relativistic motion of the orbiting plasma and the gravitational pull of the black hole. The physical origin of the QPO has long been debated, but is often attributed to Lense-Thirring precession, a General Relativistic effect causing the inner flow to precess as the spinning black hole twists up the surrounding space-time. This predicts a characteristic rocking of the iron line between red and blue shift as the receding and approaching sides of the disk are respectively illuminated. Here we report on XMM-Newton and NuSTAR observations of the black hole binary H 1743-322 in which the line energy varies systematically over the ~4 s QPO cycle (3.70 sigma significance), as predicted. This provides strong evidence that the QPO is produced by Lense-Thirring precession, constituting the first detection of this effect in the strong gravitation regime. There are however elements of our results harder to explain, with one section of data behaving differently to all the others. Our result enables the future application of tomographic techniques to map the inner regions of black hole accretion disks.
description: Published online in MNRAS
title: Identifiability of Additive, Time-Varying Actuator and Sensor Faults by State Augmentation
Creators: name: Upchurch, Jason M.
Publisher: name: Old Dominion University
publisherIdentifier: https://ror.org/04zjtrb98
publisherIdentifierScheme: ROR
Year: 2013

description: Faults in dynamical systems can have serious safety and reliability implications. For example, actuator and sensor faults have been factors in past incidents and mishaps in many aerospace systems. A large body of research is devoted to developing methods to detect and identify actuator and sensor faults in such systems.

One fault detection and identification menthol employs state augmentation, whereby a set of time-varying faults of interest are modeled as outputs of exogenous linear, time-invariant systems and augmented to the state of the nominal system model. The resulting model represents the system dynamics due to a particular actuator-sensor fault configuration. Typically, a filter is associated with each model, and a test matches the model most closely associated with the present system state estimates and measurements. A significant portion of the model-based fault detection and identification literature is concerned with the design of such filters. A basic requirement of these techniques i8 that the modeled fault configuration of interest be identifiable.

Recent research has led to a set of necessary and sufficient conditions for identifiability of additive step faults. Such faults manifest themselves as. for example, a stuck control surface or a constant sensor bias. This thesis extends these results by presenting necessary and sufficient conditions for identifiability of additive, time­ varying faults affecting arbitrary combinations of actuators and sensors, either alone or simultaneously.

The application of the main theorems is illustrated with two case studies, which provide some insight into how the conditions may be used to check the identifiability of fault configurations of interest for a given system. It is shown that while state augmentation can be used to identify certain fault configurations, other fault configurations cannot be identified. Furthermore. one limitation of model-based methods is that innumerable fault configurations are possible. However, identifiability of known, credible fault configurations can be tested using the theorems presented in this thesis.
Taming intermittent plasticity at small scales
Creators: name: Zhanga, Peng
name: Salman, Oguz Umut
name: Zhang, Jin-Yu
name: Liu, Gang
name: Weiss, Jérôme
name: Truskinovsky, Lev
name: Sun, Jun
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The extreme miniaturization in modern technology calls for deeper insights into the non-conventional, fluctuation dominated mechanics of materials at micro- to nano-scales. Both experiments and simulations show that sub-micron face-centered-cubic (FCC) crystals exhibit high yield strength, which is, however, compromised by intermittent, power law distributed strain fluctuations, typical of wild plasticity. At macro-scales, the same bulk materials show mild plasticity characterized by bounded, uncorrelated fluctuations. Both anomalous strength and intermittency appear therefore as size effects. While the former is highly desirable, the latter is detrimental because stochastic dislocation avalanches interfere with forming processes and endanger structural stability. In this paper we show that defectiveness, which is used in classical metallurgy to harden materials, can be used at sub-micron scales to suppress intermittent fluctuations. We quantify the coexistence of wild and mild fluctuations in compressed Al alloys micro-pillars, demonstrate that the statistical nature of fluctuations is determined by sample size, and propose quantitative strategies allowing one to temper plastic intermittency by artificially tailored disorder. Our experimental results are rationalized using a theoretical framework which quantifies the competition between external (size related) and internal (disorder related) length scales.
description: 36 pages, 15 figues
Mixed convection in turbulent channels with unstable stratification
Creators: name: Pirozzoli, Sergio
name: Bernardini, Matteo
name: Verzicco, Roberto
name: Orlandi, Paolo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study turbulent flows in planar channels with unstable thermal stratification, using direct numerical simulations in a wide range of Reynolds and Rayleigh numbers and reaching flow conditions which are representative of asymptotic developed turbulence. The combined effect of forced and free convection produces a peculiar pattern of quasi--streamwise rollers occupying the full channel thickness with aspect--ratio considerably higher than unity; it has been observed that they have an important redistributing effect on temperature and momentum. The mean values and the variances of the flow variables do not appear to follow Prandtl's scaling in the flow regime near free convection, except for the temperature and vertical velocity fluctuations, which are more affected by turbulent plumes. Nevertheless, we find that the Monin--Obukhov theory still yields a useful representation of the main flow features. In particular, the widely used Businger--Dyer relationships provide a convenient way of accounting for the bulk effects of shear and buoyancy, although individual profiles may vary widely from the alleged trends. Significant deviations are found in DNS with respect to the commonly used parametrization of the mean velocity in the light-wind regime, which may have important practical impact in models of atmospheric dynamics. Finally, for modelling purposes, we devise a set of empirical predictive formulas for the heat flux and friction coefficients which can be used with about $10\%$ maximum error in a wide range of flow parameters.
On low rank 4d $\mathcal{N}=2$ SCFTs
Creators: name: Li, Bohan
name: Xie, Dan
name: Yan, Wenbin
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Representation Theory (math.RT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: There are two major ways of constructing 4d $\mathcal{N}=2$ superconformal field theories (SCFTs): the first one is putting a 6d $(2,0)$ theory on a punctured Riemann surface (class-S theory), and the second one is putting type IIB string theory on a 3d canonical singularity. As there are interests on low rank theories, we search all the possibilities from above two constructions. Most of those theories are engineered by class-S theory with irregular singularities, and we find a universal formula for the rank of theory so that a complete search is possible. We then compute various physical quantities of those theories, such as the central charges, flavor symmetry, associated vertex operator algebra and Higgs branch, etc. One of interesting consequence of our results are the prediction of many new isomorphism of 2d vertex operator algebra.
description: 57 tables, 3 figures, 53 pages, Comments Welcome
On two-loop divergences of effective action in $6D$, ${\cal N}=(1,1)$ SYM theory
Creators: name: Buchbinder, I. L.
name: Ivanov, E. A.
name: Merzlikin, B. S.
name: Stepanyantz, K. V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the off-shell structure of the two-loop effective action in $6D, {\cal N}=(1,1)$ supersymmetric gauge theories formulated in ${\cal N}=(1,0)$ harmonic superspace. The off-shell effective action involving all fields of $6D, {\cal N}=(1,1)$ supermultiplet is constructed by the harmonic superfield background field method, which ensures both manifest gauge covariance and manifest ${\cal N}=(1,0)$ supersymmetry. We analyze the off-shell divergences dependent on both gauge and hypermultiplet superfields and argue that the gauge invariance of the divergences is consistent with the non-locality in harmonics. The two-loop contributions to the effective action are given by harmonic supergraphs with the background gauge and hypermultiplet superfields. The procedure is developed to operate with the harmonic-dependent superpropagators in the two-loop supergraphs within the superfield dimensional regularization. We explicitly calculate the gauge and the hypermultiplet-mixed divergences as the coefficients of $\frac{1}{{\varepsilon}^2}$ and demonstrate that the corresponding expressions are non-local in harmonics.
description: 1+25 pages, appendices added
Εξόρυξη γνώσης από δεδομένα δικηγορικού γραφείου διαχείρισης ληξιπρόθεσμων οφειλών
Creators: name: Ποζατζίδης, Αναστάσιος
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Ληξιπρόθεσμες οφειλές
subject: Δάνεια
subject: Εξόρυξη γνώσης
subject: Μηχανική μάθηση
subject: Αλγόριθμοι
subject: Νομικά δεδομένα
subject: Python

description: Η ανάπτυξη των παραγωγικών δυνάμεων αποτελεί στόχο κάθε κοινωνικοοικονομικού σχηματισμού, στα πλαίσια της σύγχρονης κοινωνίας και της ελεύθερης οικονομίας , η ανάπτυξη και η βελτίωση της παραγωγικότητας αποτελεί στόχο κάθε ξεχωριστής επιχείρησης τόσο σε διεθνές όσο και σε εγχώριο πεδίο δράσης. Εξάλλου η εξέλιξη της παραγωγής με νέες παραγωγικές δυνατότητες καθιστά την κάθε επιχείρηση πιο ανθεκτική έναντι του ανταγωνισμού και άρα πιθανότερο να επιβιώσει και να εξελιχθεί. Η εισαγωγή νέων, τεχνολογικά προηγμένων, τεχνικών και μεθόδων είναι ένας από τους τρόπους εξέλιξης της παραγωγής καθώς καθιστά ευκολότερη τη διεκπεραίωση, παρακολούθηση, έλεγχο και πρόβλεψη των διαδικασιών τις οποίες πρέπει να ακολουθήσει η εκάστοτε επιχείρηση. Οδηγεί επίσης σε συγκεκριμένες αποφάσεις οι οποίες μπορούν να αλλάξουν τους επιμέρους στόχους ακόμα και τη στρατηγική της επιχείρησης. Σε αυτά τα πλαίσια η επιστήμη των δεδομένων και πιο συγκεκριμένα η εξόρυξη γνώσης από την πληθώρα δεδομένων τα οποία ανήκουν στην εκάστοτε επιχείρηση καθίστανται πολύτιμα και η ανάλυση τους αποτελεί σημαντικό στόχο που βοηθάει στην κατανόηση της οικονομικής και παραγωγικής πραγματικότητας και άρα στην αποκάλυψη των πιθανών τάσεων που παρατηρούνται , δηλαδή στην δυνατότητα πρόβλεψης και χάραξης στρατηγικής. Με αυτή τη σκέψη ως βασικό σημείο εκκίνησης πραγματοποιήθηκε η διπλωματική διατριβή. Τα τμήματα πληροφορικής καθίστανται όλο και πιο σημαντικά για οποιαδήποτε επιχείρηση. Το ίδιο συμβαίνει και για τις εταιρείες που δραστηριοποιούνται στον τραπεζικό τομέα κι δεν είναι τράπεζες, όπως για παράδειγμα τα δικηγορικά γραφεία μέσα στα οποία υπάρχει call center. Στη σύγχρονη Ελλάδα , τα συγκεκριμένα γραφεία έρχονται σε επικοινωνία καθημερινά με εκατοντάδες πολίτες και διεκπεραιώνουν πολλές σημαντικές ενέργειες που αφορούν οφειλές δανειοληπτών ή ληξιπρόθεσμων λογαριασμών και αντίστοιχα ενημερώνουν τα ιδρύματα που παρείχαν το δάνειο ή τους ανήκει μια παροχή. Η λειτουργία αυτή καταλήγει να δημιουργεί βάσεις δεδομένων με πολλά διαφορετικά στοιχεία από διαφορετικές πηγές. Η άντληση, επεξεργασία και ανάλυση από τα δεδομένα μπορεί να παρέχει πολύτιμα εργαλεία και την εξόρυξη κατάλληλης γνώσης για την βελτιστοποίηση των διαδικασιών της επιχείρησης ακόμα και την αλλαγή στρατηγικής. Απασχόλησε κυρίως η εφαρμογή τεχνικών για την δυνατότητα πρόβλεψης αποπληρωμής των οφειλετών ή η συνέπεια τους.
Distributed recovery of jointly sparse signals under communication constraints
Creators: name: Fosson, Sophie M.
name: Matamoros, Javier
name: Anton-Haro, Carles
name: Magli, Enrico
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optimization and Control (math.OC)
subject: Multiagent Systems (cs.MA)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: The problem of the distributed recovery of jointly sparse signals has attracted much attention recently. Let us assume that the nodes of a network observe different sparse signals with common support; starting from linear, compressed measurements, and exploiting network communication, each node aims at reconstructing the support and the non-zero values of its observed signal. In the literature, distributed greedy algorithms have been proposed to tackle this problem, among which the most reliable ones require a large amount of transmitted data, which barely adapts to realistic network communication constraints. In this work, we address the problem through a reweighted $\ell_1$ soft thresholding technique, in which the threshold is iteratively tuned based on the current estimate of the support. The proposed method adapts to constrained networks, as it requires only local communication among neighbors, and the transmitted messages are indices from a finite set. We analytically prove the convergence of the proposed algorithm and we show that it outperforms the state-of-the-art greedy methods in terms of balance between recovery accuracy and communication load.
title: Impact of Urban Area Growth on ASCAT Backscatter Time Series as Depicted by Sentinel-1
Creators: name: Stollhof, Gabriel
Publisher: name: TU Wien
Year: 2023
Subjects: subject: Fernerkundung
subject: urbanes Wachstum
subject: remote sensing
subject: urban growth

description: Urbane Regionen haben aufgrund ihrer physikalischen Eigenschaften signifikanten Einfluss auf Fernerkundungsdaten. Die vorliegende Arbeit beschäftigt sich mit der Untersuchung des Rückstreuverhaltens in urbanen Gebieten und dessen Auswirkungen auf Datensätze des auf den MetOp Satelliten montierten Advanced Scatterometer Sensors mithilfe von hochauflösenden Daten des C-SAR Sensorsystems der Sentinel-1 Satellitenmission. Hierfür wurden in fünf unterschiedlichen Regionen die Datensätze beider Sensorsysteme zeitlich und räumlich angeglichen und ihre Korrelation berechnet. Drei der fünf Sentinel-1 Datensätze eigneten sich für tiefergehende Experimente, die die Eingrenzung vieler verschiedener Einflüsse auf das Rückstreuverhalten inklusive mehrerer Arten von urbanem Wachstum, ermöglichten. Die durchgeführten Experimente und die benutzten Algorithmen ermöglichten keine exakte Quantifizierung des Einflusses von urbanem Wachstum auf die Daten, jedoch war es möglich eine Ausgangsbasis für zukünftige Weiterentwicklungen zu erstellen.
description: Urban areas have a significant effect on different types of datasets collected by remote sensing sensor systems. This thesis reports the investigation of high-resolution datasets derived from the Sentinel-1 C-SAR instrument regarding the effects of urban growth and its influence on the data derived from the Advanced Scatterometer instrument of the MetOp satellite. Datasets of both sensor systems from five different regions were matched and analyzed regarding their correlation. From the Sentinel-1 datasets gradient maps were created which allowed a detailed analysis of fine-scale temporal changes regarding backscatter behaviour. Three of the five Sentinel-1 datasets were suitable for in-depth experiments, which resulted in the isolation of many different kinds of influences on the backscatter data including some kinds of urban growth. With these experiments and the used algorithms an exact quantification of the influence of urban growth on the datasets was not possible but a baseline for further development has been created.
Controlling crystallization: What liquid structure and dynamics reveal about crystal nucleation mechanisms
Creators: name: Rogal, Jutta
name: Leines, Grisell Díaz
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Over recent years, molecular simulations have provided invaluable insights into the microscopic processes governing the initial stages of crystal nucleation and growth. A key aspect that has been observed in many different systems is the formation of precursors in the supercooled liquid that precedes the emergence of crystalline nuclei. The structural and dynamical properties of these precursors determine to a large extend the nucleation probability as well as the formation of specific polymorphs. This novel microscopic view on nucleation mechanisms has further implications for our understanding of the nucleating ability and polymorph selectivity of nucleating agents, as these appear to be strongly linked to their ability in modifying structural and dynamical characteristics of the supercooled liquid, namely liquid heterogeneity. In this perspective, we highlight recent progress in exploring the connection between liquid heterogeneity and crystallization, including the effects of templates, and the potential impact for controlling crystallization processes.
Structure of the pairing gap from orbital nematic fluctuations
Creators: name: Agatsuma, Tomoaki
name: Yamase, Hiroyuki
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study superconducting instability from orbital nematic fluctuations in a minimal model consisting of the $d_{xz}$ and $d_{yz}$ orbitals, and choose model parameters which capture the typical Fermi surface geometry observed in iron-based superconductors. We solve the Eliashberg equations down to low temperatures with keeping the renormalization function and a full momentum dependence of the pairing gap. When superconductivity occurs in the tetragonal phase, we find that the pairing gap exhibits a weak momentum dependence over the Fermi surfaces. The superconducting instability occurs also inside the nematic phase. When the $d_{xz}$ orbital is occupied more than the $d_{yz}$ orbital in the nematic phase, a larger (smaller) gap is realized on the Fermi-surface parts, where the $d_{xz}$ ($d_{yz}$) orbital component is dominant, leading to a substantial momentum dependence of the pairing gap on the hole Fermi surfaces. On the other hand, the momentum dependence of the gap is weak on the electron Fermi surfaces. We also find that while the leading instability is the so-called $s_{++}$-wave symmetry, the second leading one is $d_{x^2-y^2}$-wave symmetry. In particular, these two states are nearly degenerate in the tetragonal phase whereas such quasi-degeneracy is lifted in the nematic phase and the $d_{x^2-y^2}$-wave symmetry changes to highly anisotropic $s$-wave symmetry.
description: 19 pages, 8 figures
Lipid degradation and photosynthetic traits after prolonged darkness in four Antarctic benthic diatoms, including the newly described species Planothidium wetzelii sp. nov.
Creators: name: Juchem, Desirée P.
name: Schimani, Katherina
name: Holzinger, Andreas
name: Permann, Charlotte
name: Abarca, Nélida
name: Skibbe, Oliver
name: Zimmermann, Jonas
name: Graeve, Martin
name: Karsten, Ulf
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: Antarctica
subject: benthic diatoms
subject: photosynthesis
subject: polar night
subject: lipid consumption
subject: plastid degradation
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie::570 Biowissenschaften; Biologie

description: In polar regions, the microphytobenthos has important ecological functions in shallow-water habitats, such as on top of coastal sediments. This community is dominated by benthic diatoms, which contribute significantly to primary production and biogeochemical cycling while also being an important component of polar food webs. Polar diatoms are able to cope with markedly changing light conditions and prolonged periods of darkness during the polar night in Antarctica. However, the underlying mechanisms are poorly understood. In this study, five strains of Antarctic benthic diatoms were isolated in the field, and the resulting unialgal cultures were identified as four distinct species, of which one is described as a new species, Planothidium wetzelii sp. nov. All four species were thoroughly examined using physiological, cell biological, and biochemical methods over a fully controlled dark period of 3 months. The results showed that the utilization of storage lipids is one of the key mechanisms in Antarctic benthic diatoms to survive the polar night, although different fatty acids were involved in the investigated taxa. In all tested species, the storage lipid content declined significantly, along with an ultrastructurally observable degradation of the chloroplasts. Surprisingly, photosynthetic performance did not change significantly despite chloroplasts decreasing in thylakoid membranes and an increased number of plastoglobules. Thus, a combination of biochemical and cell biological mechanisms allows Antarctic benthic diatoms to survive the polar night.
Spin-orbit coupling in Fe-based superconductors
Creators: name: Korshunov, M. M.
name: Togushova, Yu. N.
name: Eremin, I.
name: Hirschfeld, P. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the spin resonance peak in recently discovered iron-based superconductors. The resonance peak observed in inelastic neutron scattering experiments agrees well with predicted results for the extended $s$-wave ($s_\pm$) gap symmetry. Recent neutron scattering measurements show that there is a disparity between longitudinal and transverse components of the dynamical spin susceptibility. Such breaking of the spin-rotational invariance in the spin-liquid phase can occur due to spin-orbit coupling. We study the role of the spin-orbit interaction in the multiorbital model for Fe-pnictides and show how it affects the spin resonance feature.
description: 3 pages, 1 figure
A new technique for elucidating $β$-decay schemes which involve daughter nuclei with very low energy excited states
Creators: name: Venhart, M.
name: Wood, J. L.
name: Boston, A. J.
name: Cocolios, T. E.
name: Harkness-Brennan, L. J.
name: Herzberg, R. -D.
name: Joss, D. T.
name: Judson, D. S.
name: Kliman, J.
name: Matousek, V.
name: Motycak, S.
name: Page, R. D.
name: Patel, A.
name: Petrik, K.
name: Sedlak, M.
name: Veselsky, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A new technique of elucidating $β$-decay schemes of isotopes with large density of states at low excitation energies has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique has been demonstrated on the example of 183Hg decay. Mass-separated samples of 183Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed $γ$ rays energies to be determined with a precision of a few tens of electronvolts, which was sufficient for the analysis of the Rydberg-Ritz combinations in the level scheme. The timestamped structure of the data was used for unambiguous separation of $γ$ rays arising from the decay of 183Hg from those due to the daughter decays.
Proceedings of the CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 2014
Creators: name: Bailey, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: These proceedings collate lectures given at the twenty-eighth specialized course organised by the CERN Accelerator School (CAS). The course was held at the Hotel du Parc, Baden, Switzerland from 7 - 14 May 2014, in collaboration with the Paul Scherrer Institute. Following introductory lectures on accelerators and the requirements on power converters, the course covered components and topologies of the different types of power converters needed for particle accelerators. Issues of design, control and exploitation in a sometimes-hostile environment were addressed. Site visits to ABB and PSI provided an insight into state-of-the-art power converter production and operation, while topical seminars completed the programme.
description: 22 lectures, 460 pages, published as CERN Yellow Report: https://cds.cern.ch/record/1641409
Stellar Reddening Based Extinction Maps for Cosmological Applications
Creators: name: Mudur, Nayantara
name: Park, Core Francisco
name: Finkbeiner, Douglas P
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Cosmological surveys must correct their observations for the reddening of extragalactic objects by Galactic dust. Existing dust maps, however, have been found to have spatial correlations with the large-scale structure of the Universe. Errors in extinction maps can propagate systematic biases into samples of dereddened extragalactic objects and into cosmological measurements such as correlation functions between foreground lenses and background objects and the primordial non-gaussianity parameter $f_{NL}$. Emission-based maps are contaminated by the cosmic infrared background, while maps inferred from stellar-reddenings suffer from imperfect removal of quasars and galaxies from stellar catalogs. Thus, stellar-reddening based maps using catalogs without extragalactic objects offer a promising path to making dust maps with minimal correlations with large-scale structure. We present two high-latitude integrated extinction maps based on stellar reddenings, with a point spread function of full-width half-maximum 6.1' and 15'. We employ a strict selection of catalog objects to filter out galaxies and quasars and measure the spatial correlation of our extinction maps with extragalactic structure. Our galactic extinction maps have reduced spatial correlation with large scale structure relative to most existing stellar-reddening based and emission-based extinction maps.
description: 21 pages, 10 figures
Giant magnetoresistance in electrodeposited Co-Cu/Cu multilayers: origin of absence of oscillatory behaviour
Creators: name: Bakonyi, I.
name: Simon, E.
name: Tóth, B. G.
name: Péter, L.
name: Kiss, L. F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A detailed study of the evolution of the magnetoresistance was performed on electrodeposited Co/Cu multilayers with Cu layer thicknesses ranging from 0.5 nm to 4.5 nm. For thin Cu layers (up to 1.5 nm), anisotropic magnetoresistance (AMR) was observed whereas multilayers with thicker Cu layers exhibited clear giant magnetoresistance (GMR) behaviour. The GMR magnitude increased up to about 3.5 to 4 nm Cu layer thickness and slightly decreased afterwards. According to magnetic measurements, all samples exhibited ferromagnetic (FM) behaviour. The relative remanence turned out to be about 0.75 for both AMR and GMR type multilayers. This clearly indicates the absence of an antiferromagnetic (AF) coupling between adjacent magnetic layers for Cu layers even above 1.5 nm where the GMR effect occurs. The AMR behaviour at low spacer thicknesses indicates the presence of strong FM coupling (due to, e.g., pin-holes in the spacer and/or areas of the Cu layer where the layer thickness is very small). With increasing spacer thickness, the pin-hole density reduces and/or the layer thickness uniformity improves which both lead to a weakening of the FM coupling. This improvement in multilayer structure quality results in a better separation of magnetic layers and the weaker coupling (or complete absence of interlayer coupling) enables a more random magnetization orientation of adjacent layers, all this leading to an increase of the GMR. Coercive field and zero-field resistivity measurements as well as the results of a structural study reported earlier on the same multilayers provide independent evidence for the microstructural features established here. The large GMR reported previously on such Co/Cu multilayers at Cu layer thicknesses around 1 nm can be attributed to the presence of a fairly large superparamagnetic (SPM) fraction rather than being due to a strong AF coupling.
description: 24 pages, 6 figures
Design of gas adsorption systems with phase change materials aided by topology optimisation method
Creators: name: Silva Prado, Diego
Publisher: name: Imperial College London
Year: 2022

description: The use of natural gas has become increasingly attractive for the industrial sector, economically or ecologically, and its storage assumes an essential role in this process. The mechanism of mass transfer by adsorption is encountered in several areas of science and is already used for storing natural gas when applied to gas adsorption tanks. In latent heat storage applications, phase change materials significantly benefit thermal stability and storage-to-volume ratio. Work using phase change materials in adsorption tanks demonstrates improvements in the adsorption capacity of the tanks by improving the thermal behaviour of the set, and the results are influenced by the geometry and positioning of the bodies belonging to the system, signalling the opportunity to optimise the distribution of material inside the tank. A topology optimisation method is a generic tool for distributing material within a domain. In the last decades, it has presented significant progress in its implementation and the possibility of exploring the existing manufacturing methods. The present work explores the topology optimisation method in designing adsorption systems with phase change materials in their interior. Initially, the displacement of the air masses in the surroundings of an adsorption system is simulated simultaneously with the adsorption process simulation in its interior. This method allows a variable convection heat exchange through the system's external walls. The convection distribution along the external wall is evaluated to strengthen the assumption of constant external convection on the external walls of a cylindrical vessel, which is the object of study of the topology optimisation. Results show that the variable-h approach is indicated for complex-shaped vessels, whereas the conventional approach may be applied for cylindrical vessels. The second part of this work addresses the internal optimisation of adsorption tanks with phase change materials (PCM). Two approaches are presented. In the first approach, the phase change material is particulate and mixed with particulate adsorbent. A Semi-Analytic model is compared to the topology optimisation method to check the total PCM ratio and how boundary conditions affect the solution. The topology optimisation method produces a graded solution for the optimised PCM ratio in the mixture. In contrast with the first approach, the last approach optimises condensed PCM. It assumes that PCM is one or more continuous bodies inside the adsorption system. The results for all these approaches are presented and compared. The study shows that topology optimisation may produce optimised PCM distributions inside adsorption systems and be an option when mixtures are unavailable.
Exact conditions for Quasi-normal modes of extremal M5-branes and Exact WKB analysis
Creators: name: Imaizumi, Keita
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the quasi-normal modes (QNMs) of a massless scalar perturbation to the extremal M5-branes metric by using the exact WKB analysis. The exact WKB analysis provides two exact QNMs conditions depending on the argument of the complex frequency of the perturbation. The exact conditions show that the discontinuity of the perturbative part of the QNMs leads the non-perturbative part of themselves. We also find a new example of the Seiberg-Witten/gravity correspondence, which helps us to compute the QNMs from our conditions.
description: 25 pages, 8 figures
Measurements of open heavy-flavour production with ALICE at the LHC
Creators: name: De, Sudipan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In ALICE, open heavy-flavour production is studied through the measurements of the leptons (electrons and muons) from heavy-flavour hadron decays at central and forward rapidity and via the reconstruction of D-meson hadronic decays at mid-rapidity. An overview of the open heavy-flavour production with ALICE in pp ($\sqrt{s}$ = 2.76 TeV and 7 TeV), p--Pb ($\sqrt {s_{\rm NN}}$ = 5.02 TeV) and Pb--Pb ($\sqrt {s_{\rm NN}}$ = 2.76 TeV) collisions will be presented. We will discuss the production cross sections, modifications of the transverse momentum distributions, azimuthal anisotropic emissions and correlations with hadrons in comparison with various theoretical predictions.
description: 6 pages, 10 figures, Proceedings of the XIIth International Conference on Beauty, Charm, and Hyperons in Hadronic Interactions (BEACH2016), Fairfax, Virginia USA, 12-18 June 2016
Machine learning methods for facial attribute editing
Creators: name: Ververas, Evangelos
Publisher: name: Imperial College London
Year: 2022

description: In this thesis, we explore the problem of facial attribute analysis and editing in images, from the scope of two major fields of Machine Learning, those of Components Analysis (CA) and Deep Learning (DL). First, we present a CA method for analysing and editing facial data. Then, we present a DL algorithm for animating facial images according to expressions and speech. Finally, we present a method for improving gaze estimation generalisation to unseen image domains and showcase applications to eye gaze editing. Although CA methods are able to capture only linear relationships in data, they can still be useful with well-aligned data, such as UV maps of facial texture. In this Thesis, we propose robust extensions of the Joint and Individual Variance Explained (JIVE) method, for the recovery of joint and individual components in visual facial data, captured in unconstrained conditions and possibly containing sparse non-Gaussian errors and missing data. We demonstrate the effectiveness of the proposed methods to several computer vision applications, namely facial expression synthesis and 2D and 3D face age progression in-the-wild. CA methods usually fall short in image generation, as they fail to generate details. On the contrary, Image-to-image (i2i) translation, which is the problem of translating images between image domains, has recently seen remarkable progress since the advent of DL and Generative Adversarial Networks (GANs). In this Thesis, we study the problem of i2i translation, under a set of continuous parameters that correspond to statistical blendshape models of facial motion. We show that it is possible to edit facial images according to expression and speech blendshapes using ``sliders'', which are more flexible than discrete expressions or action units. Lastly, realistically animating gaze is crucial for achieving high quality facial animations. To this end, large datasets of faces with gaze annotations are required for training. In this Thesis, we present a weakly-supervised method for improving gaze estimation generalization to unseen domains, by harnessing arbitrary unlabelled ``in-the-wild'' face images. Unlike previous methods, we tackle gaze estimation as end-to-end, dense 3D reconstruction of eyes and experimentally validate the benefits of this choice. Particularly, we show improvements in semi-supervised and cross-dataset gaze estimation. Finally, we showcase how our methods can be employed for training efficient models for gaze editing.