cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Equatorial extreme-mass-ratio inspirals in Kerr black holes with scalar hair spacetimes
Creators: name: Collodel, Lucas G.
name: Doneva, Daniela D.
name: Yazadjiev, Stoytcho S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work we analyze some judiciously chosen solutions of Kerr Black Holes with Scalar Hair (KBHsSH) of special interest for Gravitational Wave (GW) events originated from Extreme Mass Ratio Inspirals (EMRIs). Because of the off-center distribution of energy density, these spacetimes are warped in such a way that not all metric functions behave monotonically on the equatorial plane as in the exterior region of Kerr black holes (KBHs). This has great impact on the orbital parameters, which in turn affects the imprints on signals descendant from EMRIs in a adiabatic evolution. By investigating circular obit parameters, we unveil what qualitative features could be present in the signals that are new and distinct compared to KBHs, and we evolve some inspirals by employing the usual quadrupole formula approximation. We show that the frequencies of the emitted signals behave nonmonotonically, i.e. they can backward chirp, and for some particular cases they can become arbitrarily small, falling below LISA's sensibility range. Finally, we present two sets of waveforms produced by a noncircular EMRI in which the compact object (CO) follows a type of geodesic motion typically present in spacetimes with a static ring (SR), in which the compact object is periodically momentarily at rest.
Fermion Sign Problem in Path Integral Monte Carlo Simulations: Grand-canonical ensemble
Creators: name: Dornheim, Tobias
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present a practical analysis of the fermion sign problem in fermionic path integral Monte Carlo (PIMC) simulations in the grand-canonical ensemble (GCE). As a representative model system, we consider electrons in a $2D$ harmonic trap. We find that the sign problem in the GCE is even more severe than in the canonical ensemble at the same conditions, which, in general, makes the latter the preferred option. Despite these difficulties, we show that fermionic PIMC simulations in the GCE are still feasible in many cases, which potentially gives access to important quantities like the compressiblity or the Matsubara Greens function. This has important implications for contemporary fields of research such as warm dense matter, ultracold atoms, and electrons in quantum dots.
title: Erklärung und Visualisierung von strukturellem Wissen in bipartiten Graphen
Creators: name: Dürrschnabel, Dominik
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Datensätze, welche die Form von bipartiten Graphen haben, kommen in vielen Bereichen vor. Beispiele für solche Datensätze sind Nutzer und ihre Vorlieben in sozialen Netzwerken oder die Interaktionen zwischen Krankheiten und Medikamenten in der Biomedizin. In der Dissertation wird die Entdeckung, Erklärung und Visualisierung von strukturellem Wissen in bipartiten Graphen bearbeitet. Dabei werden im Großen und Ganzen drei verschiedene Ansätze verfolgt. Im ersten Teil der Dissertation werden Algorithmen für die Entdeckung von für den Wissensentdeckungsprozess relevanten Teilstrukturen erforscht. Der zweite Teil beschäftigt sich mit der Visualisierung von Ord-
nungsstrukturen, welche sich aus den Datensätzen berechnen. Im letzten Teil wird ein Ansatz vorgestellt, den Hüllenoperators der formalen Begriffsanalyse zu lernen. Mithilfe des gelernten Operators können dann formale Begriffe in niedrigdimensionale Vektorräume eingebettet werden. Viele der in der Dissertation untersuchten Fragen sind mit NP-schweren Problemen verknüpft. Jedes dieser Probleme bringt seine eigenen Schwierigkeiten mit, was dazu führt, dass eine Kombination von Ansätzen aus verschiedenen Teilbereichen der Informatik in der Dissertation bearbeitet wird.
Knowledge Graph Reasoning with Relational Digraph
Creators: name: Zhang, Yongqi
name: Yao, Quanming
Publisher: name: arXiv
Year: 2021
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Reasoning on the knowledge graph (KG) aims to infer new facts from existing ones. Methods based on the relational path have shown strong, interpretable, and transferable reasoning ability. However, paths are naturally limited in capturing local evidence in graphs. In this paper, we introduce a novel relational structure, i.e., relational directed graph (r-digraph), which is composed of overlapped relational paths, to capture the KG's local evidence. Since the r- digraphs are more complex than paths, how to efficiently construct and effectively learn from them are challenging. Directly encoding the r-digraphs cannot scale well and capturing query-dependent information is hard in r-digraphs. We propose a variant of graph neural network, i.e., RED-GNN, to address the above challenges. Specifically, RED-GNN makes use of dynamic programming to recursively encodes multiple r-digraphs with shared edges, and utilizes a query-dependent attention mechanism to select the strongly correlated edges. We demonstrate that RED-GNN is not only efficient but also can achieve significant performance gains in both inductive and transductive reasoning tasks over existing methods. Besides, the learned attention weights in RED-GNN can exhibit interpretable evidence for KG reasoning.
title: Datenpartitionierung und Anfrageoptimierung im Semantischen Internet of Things
Creators: name: Warnke, Benjamin
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Die Fähigkeit von Semantik Web Datenbanken, heterogene Daten zu verarbeiten, ermöglicht innovative Anwendungen in Wissenschaft, Wirtschaft und Technologie. Der Austausch der Daten zwischen verschiedensten Geräten ist allerdings mit einem hohen Datenverkehr und somit Energieverbrauch verbunden. Im Bereich des Internet of Things (IoT) ist von einer hohen Zahl batteriebetriebener Geräte auszugehen, daher verkürzt ein hoher Energieverbrauch die Lebensdauer der Geräte. Deshalb werden in der hier vorgestellten Dissertation verschiedene Strategien der Verteilung von Daten sowie deren Verarbeitung eingeführt und evaluiert. Dabei wird insbesondere auch die
Heterogenität der Netzwerkarchitektur berücksichtigt.
title: Protokolle für den Authentifizierten Schlüsselaustausch mit Strikten Sicherheitsschranken
Creators: name: Riepel, Doreen
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Authentifizierter Schlüsselaustausch bildet die Grundlage für kryptographisch sichere, digitale Kommunikation. Entsprechende Protokolle werden heutzutage in Anwendungen mit Milliarden von Nutzern eingesetzt. Um deren Sicherheit formal beweisen zu können, definiert man ein Sicherheitsmodell und die Sicherheit eines Protokolls wird dann durch eine Schranke bezüglich eines mathematisch schweren Problems ausgedrückt. Allerdings hängen diese Schranken in vorherigen Arbeiten zumeist von weiteren Faktoren ab und unglücklicherweise auch von der Anzahl der
Nutzer im System. Um das geforderte Sicherheitslevel zu erreichen, müssen die Systemparameter dementsprechend vergrößert werden oder der Beweis verliert seine Aussagekraft. Das Ziel dieser Arbeit besteht darin, strikte Sicherheitsschranken für Schlüsselaustauschprotokolle zu untersuchen.

Strikt bedeutet hier, dass sie unabhängig von der Anzahl der Nutzer oder anderer Faktoren gelten. Zunächst werden konkrete Schranken für die Sicherheit zweier praktischer Protokolle in Gruppen primer Ordnung analysiert. Des Weiteren zeigen wir, wie man Protokolle mit strikten Sicherheitsschranken generisch aus anderen kryptographischen Primitiven konstruiert. Unsere resultierenden Kompositionstheoreme vereinfachen somit zukünftige Sicherheitsbeweise. Als letztes wird ein Protokoll konstruiert, das die Gruppenwirkung auf einer Menge von supersingulären elliptischen Kurven ausnutzt. Diese Instanziierung ist ein vielsprechender Kandidat für quantenresistente Kryptographie.
Multimodal Remote Sensing Benchmark Datasets for Land Cover Classification with A Shared and Specific Feature Learning Model
Creators: name: Hong, Danfeng
name: Hu, Jingliang
name: Yao, Jing
name: Chanussot, Jocelyn
name: Zhu, Xiao Xiang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: As remote sensing (RS) data obtained from different sensors become available largely and openly, multimodal data processing and analysis techniques have been garnering increasing interest in the RS and geoscience community. However, due to the gap between different modalities in terms of imaging sensors, resolutions, and contents, embedding their complementary information into a consistent, compact, accurate, and discriminative representation, to a great extent, remains challenging. To this end, we propose a shared and specific feature learning (S2FL) model. S2FL is capable of decomposing multimodal RS data into modality-shared and modality-specific components, enabling the information blending of multi-modalities more effectively, particularly for heterogeneous data sources. Moreover, to better assess multimodal baselines and the newly-proposed S2FL model, three multimodal RS benchmark datasets, i.e., Houston2013 -- hyperspectral and multispectral data, Berlin -- hyperspectral and synthetic aperture radar (SAR) data, Augsburg -- hyperspectral, SAR, and digital surface model (DSM) data, are released and used for land cover classification. Extensive experiments conducted on the three datasets demonstrate the superiority and advancement of our S2FL model in the task of land cover classification in comparison with previously-proposed state-of-the-art baselines. Furthermore, the baseline codes and datasets used in this paper will be made available freely at https://github.com/danfenghong/ISPRS_S2FL.
Response of a Thermoacoustic Flashover Detector to Thermal Radiation
Creators: name: Jeffrey, Zachary Tran
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Engineering
subject: Flashover
subject: Thermoacoustics

description: The thermoacoustic flashover detector is a device designed to be mounted on the helmet of a firefighter which creates a loud whistle when exposed to conditions that are consistent with flashover in order to provide firefighters with a warning and time to escape. The detector is based off a previous device designed at the University of Maryland which was operated using an electric band heater. This device was optimized by slightly altering the stack design and by the addition of approximately 0.3 mL of water to the stack, yielding an activation temperature of 125°C. Once the activation temperature was sufficiently lowered, the device was outfitted with copper fins which were designed to collect radiant heat from a propane-burning radiant panel and transfer it to the detector. When using four of these copper fins and exposed to a radiant heat flux of approximately 25 kW/m2, the detector activated around 125°C after 7 minutes. This was the first known activation of a thermoacoustic device to unconcentrated thermal radiation. The response time of the device was lowered after two more fins were added to the design. Once the detector was shown to work using radiant heat, it was tested at the Maryland Fire and Rescue Institute (MFRI) at the University of Maryland using full scale fires in order to replicate the conditions in which it would be expected to operate. While the detector did not activate during the full scale tests, the radiant panel tests proved that the design is feasible and that some slight design changes are needed in order for the detector to operate in a real fire environment.
title: Vereinigung von Struktur und Geometrie in Graph-Neuronalen Netzen
Creators: name: Gasteiger, Johannes
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Diese Arbeit stellt Methoden für das maschinelle Lernen vor, welche die strukturelle
Information von Graphen mit der geometrischen Information eines zugrundeliegenden Raums verbin-
den. Wir konzentrieren uns in erster Linie auf Graph-neuronale Netze (GNNs). Erst entwickeln wir
Methoden, um vorhandene geometrische Informationen wie Distanzen und Winkel effektiv zu reprä-
sentieren und zu nutzen. Anschließend untersuchen wir Fälle, bei denen keine explizite geometrische
Information vorliegt. Für diese Fälle entwickeln wir synthetische Koordinaten, Graphdiffusionsme-
thoden, die Einbindung von approximativem PageRank sowie approximativen optimalen Transport,
um GNNs zu verbessern. Unsere Methoden ermöglichen Modelle, die präziser und robuster sind,
besser generalisieren, weniger Trainingsdaten benötigen und zu weitaus größeren Graphen skalieren.
Twisted Poincare Invariance, Noncommutative Gauge Theories and UV-IR Mixing
Creators: name: Balachandran, A. P.
name: Pinzul, A.
name: Queiroz, A. R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In the absence of gauge fields, quantum field theories on the Groenewold-Moyal (GM) plane are invariant under a twisted action of the Poincare group if they are formulated following [1, 2, 3, 4, 5, 6]. In that formulation, such theories also have no UV-IR mixing [7]. Here we investigate UV-IR mixing in gauge theories with matter following the approach of [3, 4]. We prove that there is UV-IR mixing in the one-loop diagram of the S-matrix involving a coupling between gauge and matter fields on the GM plane, the gauge field being nonabelian. There is no UV-IR mixing if it is abelian.
description: 11 pages, 3 figures
An analysis of cultural contents of high school English textbooks in Japan
Creators: name: Kawano, Madoka
Publisher: name: University of British Columbia
Year: 2010

description: This study was conducted for the following two purposes: 1) to create and test a process by which cultural information in English textbooks in Japan can be analyzed, and 2) to examine what and how much information about foreign culture is taught in English classes in Japan. First, a process was developed from Joiner's evaluation form to gauge the cultural content of EFL textbooks. Action was taken to ensure that the process included both qualitative and quantitative steps. Second, the process entailed an analysis of the cultural content of 10 senior high school English textbooks published in Japan. The process was found to be functional and the analysis revealed that the textbooks were inadequate for the purpose of raising students' cultural awareness. The results of this study may be utilized not only for the improvement of textbooks, but also for future studies which might examine junior high school and college English textbooks.
Properties of voids in the Local Volume
Creators: name: Tikhonov, Anton
name: Klypin, Anatoly
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Current explanation of the overabundance of dark matter subhalos in the Local Group (LG) indicates that there maybe a limit on mass of a halo, which can host a galaxy. This idea can be tested using voids in the distribution of galaxies: at some level small voids should not contain any (even dwarf) galaxies. We use observational samples complete to M_B=-12 with distances less than 8 Mpc to construct the void function (VF): the distribution of sizes of voids empty of any galaxies. There are ~ 30 voids with sizes ranging from 1 to 5 Mpc. We also study the distribution of dark matter halos in very high resolution simulations of the LCDM model. The theoretical VF matches the observations remarkably well only if we use halos with circular velocities larger than 45 +/- 10 km/s. This agrees with the Local Group predictions. Small voids look quite similar to heir giant cousins: the density has a minimum at the center of a void and it increases as we get closer to the border. Thus, both the Local Group data and the nearby voids indicate that isolated halos below 45 +/- 10 km/s must not host galaxies and that small (few Mpc) voids are truly dark.
description: 5 pages 1 figure. To appear in proceedings of the conference "Galaxies in the Local Volume", Sydney, 8 to 13 July 2007
Jump-Drift and Jump-Diffusion Processes : Large Deviations for the density, the current and the jump-flow and for the excursions between jumps
Creators: name: Monthus, Cecile
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: For one-dimensional Jump-Drift and Jump-Diffusion processes converging towards some steady state, the large deviations of a long dynamical trajectory are described from two perspectives. Firstly, the joint probability of the empirical time-averaged density, of the empirical time-averaged current and of the empirical time-averaged jump-flow are studied via the large deviations at Level 2.5. Secondly, the joint probability of the empirical jumps and of the empirical excursions between consecutive jumps are analyzed via the large deviations at Level 2.5 for the alternate Markov chain that governs the series of all the jump events of a long trajectory. These two general frameworks are then applied to three examples of positive jump-drift processes without diffusion, and to two examples of jump-diffusion processes, in order to illustrate various simplifications that may occur in rate functions and in contraction procedures.
description: 29 pages
RANSIC: Fast and Highly Robust Estimation for Rotation Search and Point Cloud Registration using Invariant Compatibility
Creators: name: Sun, Lei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Correspondence-based rotation search and point cloud registration are two fundamental problems in robotics and computer vision. However, the presence of outliers, sometimes even occupying the great majority of the putative correspondences, can make many existing algorithms either fail or have very high computational cost. In this paper, we present RANSIC (RANdom Sampling with Invariant Compatibility), a fast and highly robust method applicable to both problems based on a new paradigm combining random sampling with invariance and compatibility. Generally, RANSIC starts with randomly selecting small subsets from the correspondence set, then seeks potential inliers as graph vertices from the random subsets through the compatibility tests of invariants established in each problem, and eventually returns the eligible inliers when there exists at least one K-degree vertex (K is automatically updated depending on the problem) and the residual errors satisfy a certain termination condition at the same time. In multiple synthetic and real experiments, we demonstrate that RANSIC is fast for use, robust against over 95% outliers, and also able to recall approximately 100% inliers, outperforming other state-of-the-art solvers for both the rotation search and the point cloud registration problems.
title: Die Verwendung Konzeptueller Räume für Künstliche Intelligenz
Creators: name: Bechberger, Lucas
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Ansätze im Bereich der künstlichen Intelligenz (KI) lassen sich grundsätzlich in zwei
Gruppen einteilen: Symbolische Ansätze (wie deduktives Schließen) sind interpretierbar, aber
tendenziell unflexibel, wohingegen subsymbolische Ansätze (wie maschinelles Lernen) sehr flexibel,
aber häufig nicht gut interpretierbar sind. Neurosymbolische KI kombiniert und integriert beide
Verfahren, während kognitive KI Wissen über die menschliche Kognition einbezieht. In dieser
Arbeit betrachten wir Konzepte als Kern menschlicher Kognition und konzeptuelle Räume als einen
neurosymbolischen Ansatz, der Konzepte geometrisch darstellt. Wir entwickeln Lösungen für drei
Kernprobleme, welche der breiten Nutzung dieses Ansatzes in der künstlichen Intelligenz aktuell
noch im Wege stehen: Eine saubere und umfassende Formalisierung der konzeptuellen Regionen, die
Verankerungen der konzeptuellen Räume in Sensordaten, sowie kognitiv plausible Mechanismen für
das Lernen der konzeptuellen Regionen.
Wind Flow Estimation in Thermal Sky Images for Sun Occlusion Prediction
Creators: name: Terrén-Serrano, Guillermo
name: Martínez-Ramón, Manel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Moving clouds affect the global solar irradiance that reaches the surface of the Earth. As a consequence, the amount of resources available to meet the energy demand in a smart grid powered using Photovoltaic (PV) systems depends on the shadows projected by passing clouds. This research introduces an algorithm for tracking clouds to predict Sun occlusion. Using thermal images of clouds, the algorithm is capable of estimating multiple wind velocity fields with different altitudes, velocity magnitudes and directions.
description: arXiv admin note: text overlap with arXiv:2012.02861
THE SCIENTIFIC CONFERENCE'S RESULTS: LOGISTIC VIEW "Mathematical modeling, optimization and information technology"
Creators: name: Solomon, D.
name: Stetsiuk, P.
name: Hryhorak, Maria
Publisher: name: Zenodo
Year: 2021

description: The economic consequences of the global COVID-19 pandemic have come as a shock to global and national economies, and its effects will be felt for a long time for different spheres. Quarantine restrictions have been added to traditional uncertainties such as changes in consumer demand and market conditions, reciprocal trade restrictions and climate change, which together increase logistics risks and complicate the management of the global supply chain, reduce it resilience and change its configuration.
Revisions in expressive and persuasive compositions by ninth grade writers of superior and randomly selected ability
Creators: name: Barber, Robert Ennis
Publisher: name: University of British Columbia
Year: 2010

description: This research describes the revisions made in expressive and persuasive compositions by fifteen superior and fifteen randomly selected grade nine students. Each student wrote four papers: a rough draft of an assignment designed to elicit an expressive composition; two to four days later, a revision of the expressive first draft; a rough draft of an assignment designed to elict a persuasive composition; and, finally, a revision of the persuasive first draft. All the revisions made by the students were scored using a taxonomy of revision operations. Three research questions guided the analysis to determine whether there were differences in the number and kind of revisions between the expressive and persuasive writing modes, between the superior and randomly selected ability groups, or between the first and second drafts. Few statistically significant differences were found among the variables measured. Both ability groups revised expressive writing in much the same ways. About three quarters of revisions in both writing modes involved small units of texts. Over half were surface revisions of spelling, tense, number or modality, abbreviation, punctuation or format. One third were meaning preserving changes that did not affect the meaning of the text. In persuasive writing, the superior ability group made significantly fewer revisions. Both ability groups, writing in both modes, performed about three quarters of all revisions during the second writing session while working on the second draft. The results of this research offer little evidence of mode or ability related differences in the number or kind of revisions performed on sample essays. Other than fewer revisions in persuasive writing by superior students, no consistent relation was found between rates or kinds of revision and ability scores. Few writers were observed to use revision effectively to reformulate and improve compositions as do mature, experienced writers. Most revisions performed by this ninth grade sample dealt with surface details. At this age level, it appears, revision is used as a surface and word editing process performed at the end of a writing project.
title: Modellierung von 3D-Menschen: Pose, Form, Kleidung und Interaktionen
Creators: name: Bhatnagar, Bharat Lal
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Diese Arbeit stellt neuartige Methoden zur Modellierung des Aussehens und der Hand
lungen digitaler Menschen vor, die in verschiedenen Anwendungen wie Spielen, virtuellem An-
probieren, Telepräsenz und Metaverse immer
häufiger vorkommen. Unsere vier Hauptbeiträge sind:

i) MGN (Multi-Garment Network), eine Methode zur Rekonstruktion von 3D-Kleidungsstücken und

Körperformen aus RGB-Bildern; und das SMPL+G-Modell, eine Erweiterung des SMPL-Körpermodells um Kleidungsstücke. ii) IPNet (Implicit Part Network), ein neuronales Netzwerk, das implizite Funktionen verwendet, um detaillierte menschliche 3D-Netze zu rekonstruieren und diese im SMPL-
Modell zu registrieren. iii) LoopReg, die erste vollständig differenzierbare End-to-End-Methode zur
Registrierung eines parametrischen Modells in 3D-Netzen mithilfe impliziter Funktionen. iv) BE-
HAVE, ein Datensatz und eine Methode zur Verfolgung von Mensch-Objekt-Interaktionen in 3D.
Die Arbeit bietet außerdem eine gründliche Analyse der vorgeschlagenen Methoden und ihrer Gren-

zen und schlägt Richtungen für zukünftige Arbeiten vor. Der Code, die digitale MGN-Garderobe,
der BEHAVE-Datensatz und die These sind öffentlich verfügbar.
Photophysics of two-dimensional perovskites -- learning from metal halide substitution
Creators: name: Kahmann, Simon
name: Duim, Herman
name: Fang, Hong-Hua
name: Dyksik, Mateusz
name: Adjokatse, Sampson
name: Medina, Martha Rivera
name: Pitaro, Matteo
name: Plochocka, Paulina
name: Loi, Maria A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Whereas their photophysics exhibits an intricate interplay of carriers with the lattice, most reports have so far relied on single compound studies. With the exception of variations of the organic spacer cations, the effect of constituent substitution on the photophysics and the nature of emitting species, in particular, has remained largely under-explored. Here PEA$_2$PbBr$_4$, PEA$_2$PbI$_4$, and PEA$_2$SnI$_4$ are studied through a variety of optical spectroscopy techniques to reveal a complex set of excitonic transitions at low temperature. We attribute the emergence of weak high energy features to a vibronic progression breaking Kasha's rule and highlight that the responsible phonons cannot be accessed through simple Raman spectroscopy. Bright peaks at lower energy are due to two distinct excitons, of which the upper is a convolution of a bright exciton and a localised state, whereas the lower is attributed to shallow defects. Our study offers deeper insights into the photophysics of two-dimensional perovskites through compositional substitution and highlights critical limits to the communities' current understanding of the photophysics of these compounds.
Σύστημα διαχείρισης ασφάλειας τροφίμων ISO 22000 για την τυροκόμηση τυριού φέτας Π.Ο.Π
Creators: name: Γεωργάτος Ιατρίδης, Δημήτριος
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2021
Subjects: subject: Quality management
subject: ISO 22000
subject: FMS
subject: HACCP
subject: Φέτα ΠΟΠ

description: Ο σκοπός αυτής της διπλωματικής εργασίας ήταν να διερευνηθεί, πώς μπορεί να εφαρμοστεί ένα σύστημα διαχείρισης της ασφάλειας τροφίμων, ISO/22000, σε μια μικρομεσαία επιχείρηση. Η διπλωματική εργασία πραγματοποιήθηκε παράλληλα με την υλοποίηση του προτύπου σε μια εταιρεία-μελέτη περίπτωσης. Κατά τη διάρκεια της διπλωματικής εργασίας ο δευτερεύων σκοπός ήταν να ανακαλυφθούν τα οφέλη και οι προκλήσεις για την εφαρμογή ενός συστήματος ποιότητας όπως αυτό. Το θεωρητικό πλαίσιο περιλαμβάνει βασικές έννοιες όπως η διαχείριση ποιότητας, συνεχής βελτίωση και διαχείριση εγγράφων. Το μέρος της θεωρίας παρουσιάζει επίσης την έννοια του ISO 22000 και τις κύριες πτυχές που πρέπει να ληφθούν υπόψη σε περίπτωση εκ των υστέρων εφαρμογής άλλων συστημάτων ποιότητας. Η κύρια μέθοδος στο εμπειρικό μέρος είναι η βιβλιογραφική ανασκόπηση, για την κατανόηση των προτύπων και απαιτήσεων του συστήματος διαχείρισης της ασφάλειας των τροφίμων. Συνέχεια της μελέτης αποτέλεσε η διερεύνηση μέσω ερωτηματολογίου και συνέντευξης προκειμένου να υπάρξει συγκριτική αξιολόγηση. Το κύριο αποτέλεσμα της διπλωματικής εργασίας ήταν μια κατευθυντήρια γραμμή για τον τρόπο εφαρμογής και ως προς το τι πρέπει να ληφθεί υπόψη κατά την απόκτηση του πιστοποιητικού ISO ή FSSC 22000.
The saliency of existing text as a barrier to revision in the redrafting of college students' written compositions
Creators: name: James, Edwin A. H.
Publisher: name: University of British Columbia
Year: 2010

description: The text already produced by student writers can act as a barrier to revision because the existing textual material can become so salient as to prevent writers from generating alternative text. This study investigated the effects of applying a revision heuristic designed to promote successful revision by alleviating the influence exerted by students' initial formulations of text. Inexperienced college writers were randomly assigned to two treatment conditions and asked to produce three drafts of a two-part expository composition. The experimental group composed their second drafts without access to any material produced at the draft one stage but then received back this material at the third draft stage. The control group redrafted normally, having access at all times to previous draft material. Results showed that students in the experimental group produced significantly longer and better quality final drafts with significantly higher self-evaluation scores than students in the control group produced. The mean number of idea units that were retained, removed, or added by students in either group was significantly different at both the second and third draft stages. Each part of the assignment was affected differently. Significant interactions among condition, grade point average and writing apprehension were not evident. These findings indicated that this three-stage redrafting heuristic may be a valuable technique for encouraging successful revision of students' early drafts. Further research, particularly regarding how a text communicates information, would be beneficial to our understanding of the role played by existing text in students' compositions.
Multi-particle scattering and breakdown of the Wiedemann-Franz law at a junction of N interacting quantum wires
Creators: name: Giuliano, D.
name: Nava, A.
name: Egger, R.
name: Sodano, P.
name: Buccheri, F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We analyze the charge and thermal transport at a junction of interacting quantum wires close to equilibrium. Within the framework of Tomonaga-Luttinger liquids, we compute the thermal conductance for a wide class of boundary conditions and detail the physical processes leading to the breakdown of the Wiedemann-Franz law at the junction. We show how connecting external reservoirs to the quantum wires affects the conductance tensors close to the various fixed points of the phase diagram of the junction. We therefore distinguish two types of violation of the Wiedemann-Franz law: a "trivial" one, independent of the junction dynamics and arising from the breakdown of the Fermi-liquid picture in the wire, and a junction-related counterpart, arising from multi-particle scattering processes at the junction.
description: 26 pages, 8 figures. Published version
Where infall meets outflows: turbulent dissipation probed by CH$^+$ and Ly$α$ in the starburst/AGN galaxy group SMM J02399$-$0136 at z$\sim$2.8
Creators: name: Vidal-García, A.
name: Falgarone, E.
name: Battaia, F. Arrigoni
name: Godard, B.
name: Ivison, R. J.
name: Zwaan, M. A.
name: Herrera, C.
name: Frayer, D.
name: Andreani, P.
name: Li, Q.
name: Gavazzi, R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a comparative analysis of the $\rm CH^+$(1-0) and $\rm Ly α$ lines, observed with the Atacama Large Millimeter Array (ALMA) and Keck telescope respectively, in the field of the submillimetre-selected galaxy (SMG) SMM\,J02399$-$0136 at $z\sim2.8$, which comprises a heavily obscured starburst galaxy and a broad absorption line quasar, immersed in a large $\rm Ly α$ nebula. This comparison highlights the critical role played by turbulence in channeling the energy across gas phases and scales, splitting the energy trail between hot/thermal and cool/turbulent phases in the circum-galactic medium (CGM). The unique chemical and spectroscopic properties of $\rm CH^+$ are used to infer the existence of a massive ($\sim 3.5 \times 10^{10}$ ${\rm M}_\odot$), highly turbulent reservoir of diffuse molecular gas of radius $\sim 20\,$kpc coinciding with the core of the $\rm Ly α$ nebula. The whole cool and cold CGM is shown to be inflowing towards the galaxies at a velocity $\sim$ 400 km$\,s^{-1}$. Several kpc-scale shocks are detected tentatively in $\rm CH^+$ emission. Their specific location in space and velocity with respect to the high-velocity $\rm Ly α$ emission suggests that they lie at the interface of the inflowing CGM and the high-velocity $\rm Ly α$ emission, and signpost the feeding of CGM turbulence by AGN- and stellar-driven outflows. The mass and energy budgets of the CGM require net mass accretion at a rate commensurate with the star formation rate (SFR). From this similarity, we infer that the merger-driven burst of star formation and black-hole growth are ultimately fuelled by large-scale gas accretion.
description: 24 pages, 17 figures. Accepted for publication in MNRAS
The focal plane instrumentation for the DUNE mission
Creators: name: Booth, Jeff
name: Cropper, Mark
name: Eisenhauer, Frank
name: Refregier, Alexandre
name: collaboration, the DUNE
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: DUNE (Dark Universe Explorer) is a proposed mission to measure parameters of dark energy using weak gravitational lensing The particular challenges of both optical and infrared focal planes and the DUNE baseline solution is discussed. The DUNE visible Focal Plane Array (VFP) consists of 36 large format red-sensitive CCDs, arranged in a 9x4 array together with the associated mechanical support structure and electronics processing chains. Four additional CCDs dedicated to attitude control measurements are located at the edge of the array. All CCDs are 4096 pixel red-enhanced e2v CCD203-82 devices with square 12 $μ$m pixels, operating from 550-920nm. Combining four rows of CCDs provides a total exposure time of 1500s. The VFP will be used in a closed-loop system by the spacecraft, which operates in a drift scan mode, in order to synchronize the scan and readout rates. The Near Infrared (NIR) FPA consists of a 5 x 12 mosaic of 60 Hawaii 2RG detector arrays from Teledyne, NIR bandpass filters for the wavelength bands Y, J, and H, the mechanical support structure, and the detector readout and signal processing electronics. The FPA is operated at a maximum temperature of 140 K for low dark current of 0.02e$-$/s. Each sensor chip assembly has 2048 x 2048 square pixels of 18 $μ$m size (0.15 arcsec), sensitive in the 0.8 to 1.7 $μ$m wavelength range. As the spacecraft is scanning the sky, the image motion on the NIR FPA is stabilized by a de-scanning mirror during the integration time of 300 s per detector. The total integration time of 1500 seconds is split among the three NIR wavelengths bands. DUNE has been proposed to ESA's Cosmic Vision program and has been jointly selected with SPACE for an ESA Assessment Phase which has led to the joint Euclid mission concept.
description: 9 pages; To appear in Proc. of SPIE Astronomical Telescopes and Instrumentation (23 - 28 June 2008, Marseille, France)
Confirmation of a Kinematic Diagnostic for Face-On B/P Bulges
Creators: name: Mendez-Abreu, J.
name: Corsini, E. M.
name: Debattista, Victor P.
name: De Rijcke, S.
name: Aguerri, J. A. L.
name: Pizzella, A.
name: .
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of high resolution absorption-line spectroscopy of 3 face-on galaxies, NGC 98, NGC 600, and NGC 1703 with the aim of searching for box/peanut (B/P)-shaped bulges. These observations test and confirm, for the first, time the prediction that face-on B/P-shaped bulges can be recognized by two minima in the profile along the bar's major axis of the fourth Gauss-Hermite moment h_4 of the line-of-sight velocity distribution (LOSVD). In NGC 98, a clear double minimum in h_4 is present along the major axis of the bar and before the end of the bar, as predicted. In contrast, in NGC 600, which is also a barred galaxy but lacks a substantial bulge, we do not find any significant kinematic signature for a B/P-shaped bulge. In NGC 1703, which is an unbarred control galaxy, we found no evidence of a B/P bulge. We also show directly that the LOSVD is broader at the location of the h_4 minimum in NGC 98 than elsewhere. This more direct method avoids possible artifacts associated with the degeneracy between the measurement of line-of-sight velocity dispersion and h_4.
description: 12 pages, 1 figure, accepted for publication in ApJL
Enhanced strange baryon production in Au+Au collisions compared to p+p at sqrts = 200 GeV
Creators: name: STAR Collaboration
name: Abelev, B. I.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We report on the observed differences in production rates of strange and multi-strange baryons in Au+Au collisions at sqrts = 200 GeV compared to pp interactions at the same energy. The strange baryon yields in Au+Au collisions, then scaled down by the number of participating nucleons, are enhanced relative to those measured in pp reactions. The enhancement observed increases with the strangeness content of the baryon, and increases for all strange baryons with collision centrality. The enhancement is qualitatively similar to that observed at lower collision energy sqrts =17.3 GeV. The previous observations are for the bulk production, while at intermediate pT, 1 < pT< 4 GeV/c, the strange baryons even exceed binary scaling from pp yields.
description: 7 pages, 4 figures. Printed in PRC
Non-intersecting paths and Hahn orthogonal polynomial ensemble
Creators: name: Gorin, Vadim
Publisher: name: arXiv
Year: 2007
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We compute the bulk limit of the correlation functions for the uniform measure on lozenge tilings of a hexagon. The limiting determinantal process is a translation invariant extension of the discrete sine process, which also describes the ergodic Gibbs measure of an appropriate slope.
description: 25 pages, 5 figures
title: Automatisierte Garantierte Blockchain-Technologie Verifizierung
Creators: name: Otoni, Rodrigo
Publisher: name: Gesellschaft für Informatik e.V.
Year: 2024

description: Blockchain-Technologien haben sowohl in der Wissenschaft als auch in der Industrie
große Aufmerksamkeit auf sich gezogen. Da sie als Mittel zum Halten und Manipulieren von
Finanzwerten verwendet werden, sind sie ein beliebtes Ziel von Angriffen. In der Vergangenheit
sind bereits Vermögenswerte in der Größenordnung von Millionen von US-Dollar verloren gegangen.
Vor diesem Hintergrund ist die Fähigkeit, sicherzustellen, dass keine Schwachstellen vorhanden
sind, von entscheidender Bedeutung. Die hier zusammengefasste Dissertation stützt sich auf die
jüngsten Fortschritte im Bereich der symbolischen Modellprüfung, insbesondere auf Techniken, die auf
Satisfiability Modulo Theories (SMT) und Constrained Horn Clauses (CHC) basieren, um den Bedarf
an einer automatisierten Überprüfung von Blockchain-Technologien zu decken. Der Blockchain-
Bereich wird sowohl auf der Plattform- als auch auf der Anwendungsebene durch TLA+-Spezifikationen
und Solidity-Smart-Contracts angegangen, und die Verwendung von Korrektheitszeugnissen zur
Zertifizierung der Ergebnisse von Solvern, die für die betreffenden Logikfragmente bestimmt sind,
wird als Mittel zur Gewährleistung der Korrektheit untersucht.
GGS: a Generic Geant4 Simulation package for small- and medium-sized particle detection experiments
Creators: name: Mori, Nicola
Publisher: name: arXiv
Year: 2021
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The Generic Geant4 Simulation (GGS) is a package designed to speed-up the realization and deployment of Monte Carlo simulation software based on Geant4, for small- and medium-sized high-energy experiments. For many common use cases, the task of setting up a full-featured simulation of the detector is reduced to the definition of the detector geometry, by providing generic and reusable implementations of the mandatory Geant4 user classes (particle generation, scoring, output etc.). Extensibility is provided by a simple plugin system that allows replacing of the generic implementations distributed with GGS with custom ones. These features make it especially suitable for cases where limited manpower, like during preliminary detector design studies, can severely limit the scope of an R\&D program.
description: 20 pages, 1 figure
Metallicity and Alpha-Element Abundance Measurement in Red Giant Stars from Medium Resolution Spectra
Creators: name: Kirby, Evan N.
name: Guhathakurta, Puragra
name: Sneden, Christopher
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a technique that applies spectral synthesis to medium resolution spectroscopy (MRS, R ~ 6000) in the red (6300 A < lambda < 9100 A) to measure [Fe/H] and [alpha/Fe] of individual red giant stars over a wide metallicity range. We apply our technique to 264 red giant stars in seven Galactic globular clusters and demonstrate that it reproduces the metallicities and alpha enhancements derived from high resolution spectroscopy (HRS). The MRS technique excludes the three Ca II triplet lines and instead relies on a plethora of weaker lines. Unlike empirical metallicity estimators, such as the equivalent width of the Ca II triplet, the synthetic method presented here is applicable over an arbitrarily wide metallicity range and is independent of assumptions about the alpha enhancement. Estimates of cluster mean [Fe/H] from different HRS studies show typical scatter of ~0.1 dex but can be larger than 0.2 dex for metal-rich clusters. The scatter in HRS abundance estimates among individual stars in a given cluster is also comparable to 0.1 dex. By comparison, the scatter among MRS [Fe/H] estimates of individual stars in a given cluster is ~0.1 dex for most clusters but 0.17 dex for the most metal-rich cluster, M71 ( = -0.8). A star-by-star comparison of HRS vs. MRS [alpha/Fe] estimates indicates that the precision in [alpha/Fe]_MRS is 0.05 dex. The errors in [Fe/H]_MRS and [alpha/Fe]_MRS increase beyond 0.25 dex only below signal-to-noise ratios of 20 A^(-1), which is typical for existing MRS of the red giant stars in Leo I, one of the most distant Milky Way satellites (250 kpc).
description: 16 pages, 17 figures, 7 tables, accepted for publication in ApJ
X-ray properties and evolution of high-redshift AGN, and the gas content of host galaxies
Creators: name: Vito, Fabio <1986>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2014
Subjects: FIS/05 Astronomia e astrofisica

description: In this thesis, I have investigated the evolution of the high-redshift (z > 3) AGN population by collecting data from some of the major Chandra and XMM-Newton surveys. The final sample (141 sources) is one of the largest selected at z> 3 in the X- rays and it is characterised by a very high redshift completeness (98%). I derived the spectral slopes and obscurations through a spectral anaysis and I assessed the high-z evolution by deriving the luminosity function and the number counts of the sample. The best representation of the AGN evolution is a pure density evolution (PDE) model: the AGN space density is found to decrease by a factor of 10 from z=3 to z=5. I also found that about 50% of AGN are obscured by large column densities (logNH > 23). By comparing these data with those in the Local Universe, I found a positive evolution of the obscured AGN fraction with redshift, especially for luminous (logLx > 44) AGN. I also studied the gas content of z < 1 AGN-hosting galaxies and compared it with that of inactive galaxies. For the first time, I applied to AGN a method to derive the gas mass previously used for inactive galaxies only. AGN are found to live preferentially in gas-rich galaxies. This result on the one hand can help us in understanding the AGN triggering mechanisms, on the other hand explains why AGN are preferentially hosted by star-forming galaxies.
ENERGY HARVESTING MICROGENERATORS FOR BODY SENSOR NETWORKS
Creators: name: Dadfarnia, Mehdi
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Alternative energy
subject: System science
subject: Engineering
subject: energy harvesting
subject: microgenerator
subject: optimization
subject: sensors

description: Body sensor networks have the potential to become an asset for personalizing healthcare delivery to patients in need. A key limitation for a successful implementation of body sensor networks comes from the lack of a continuous, reliable power source for the body-mounted sensors. The aim of this thesis is to model and optimize a micro-energy harvesting generator that prolongs the operational lifetime of body sensors and make them more appealing, especially for personalized healthcare purposes. It explores a model that is suitable for harvesting mechanical power generated from human body motions. Adaptive optimization algorithms are used to maximize the amount of power harvested from this model. Practicality considerations discuss the feasibility of optimization and overall effectiveness of implementing the energy harvester model with respect to body sensor power requirements and its operational lifetime.