cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Using iron line reverberation and spectroscopy to distinguish Kerr and non-Kerr black holes
Creators: name: Jiang, Jiachen
name: Bambi, Cosimo
name: Steiner, James F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The iron K$α$ line commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole candidates is produced by the illumination of a cold accretion disk by a hot corona. In this framework, the activation of a new flaring region in the hot corona imprints a time variation on the iron line spectrum. Future X-ray facilities with high time resolution and large effective areas may be able to measure the so-called 2-dimensional transfer function; that is, the iron line profile detected by a distant observer as a function of time in response to an instantaneous flare from the X-ray primary source. This work is a preliminary study to determine if and how such a technique can provide more information about the spacetime geometry around the compact object than the already possible measurements of the time-integrated iron line profile. Within our simplified model, we find that a measurement of iron line reverberation can improve constraints appreciably given a sufficiently strong signal, though that most of the information is present in the time-integrated spectrum. Our aim is to test the Kerr metric. We find that current X-ray facilities and data are unable to provide strong tests of the Kerr nature of supermassive black hole candidates. We consider an optimistic case of $10^5$ iron line photons from a next-generation data set. With such data, the reverberation model improves upon the spectral constraint by an order of magnitude.
description: 1+24 pages, 17 figures. v3: refereed version
Quantivine: A Visualization Approach for Large-scale Quantum Circuit Representation and Analysis
Creators: name: Wen, Zhen
name: Liu, Yihan
name: Tan, Siwei
name: Chen, Jieyi
name: Zhu, Minfeng
name: Han, Dongming
name: Yin, Jianwei
name: Xu, Mingliang
name: Chen, Wei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Quantum computing is a rapidly evolving field that enables exponential speed-up over classical algorithms. At the heart of this revolutionary technology are quantum circuits, which serve as vital tools for implementing, analyzing, and optimizing quantum algorithms. Recent advancements in quantum computing and the increasing capability of quantum devices have led to the development of more complex quantum circuits. However, traditional quantum circuit diagrams suffer from scalability and readability issues, which limit the efficiency of analysis and optimization processes. In this research, we propose a novel visualization approach for large-scale quantum circuits by adopting semantic analysis to facilitate the comprehension of quantum circuits. We first exploit meta-data and semantic information extracted from the underlying code of quantum circuits to create component segmentations and pattern abstractions, allowing for easier wrangling of massive circuit diagrams. We then develop Quantivine, an interactive system for exploring and understanding quantum circuits. A series of novel circuit visualizations are designed to uncover contextual details such as qubit provenance, parallelism, and entanglement. The effectiveness of Quantivine is demonstrated through two usage scenarios of quantum circuits with up to 100 qubits and a formal user evaluation with quantum experts. A free copy of this paper and all supplemental materials are available at https://osf.io/2m9yh/?view_only=0aa1618c97244f5093cd7ce15f1431f9.
description: Accepted by IEEE VIS 2023
title:  La participation du peuple à l’administration de la justice pénale en Italie: physionomie structurelle et fonctionnelle de la Corte d’assise
Creators: name: Fiorelli, Giulia
name: Donati, Luca Lupària
Publisher: name: Roma TrE-Press
Year: 2022

description: The paper seeks to provide a synthetic overview of the current and potential uses of “predictive algorithms” in the context of criminal justice systems, as well as of the critical issues arising from such tools. In the first part (§§ 2-3), the main uses of Artificial Intelligence (AI) tools within the legal systems which have implemented them will be presented. Then a synthetic framework of the possible fields of application of AI in the context of criminal justice will be provided. In the second part (§§ 4-5), the problems arising from the introduction of algorithmic tools in criminal justice will be analysed, with special attention to the fundamental rights guaranteed at a European level, the general principles of criminal law and procedure and the further juridical limits, provided by supranational and national law. In the conclusions (§ 6), an attempt will be made to define the acceptable scopes of application of algorithmic tools in the criminal justice system and to identify the necessary precautions and conditions for the use of new technologies to be consistent with the national and European legal framework.
description: Roma Tre Law Review – 01/2022
title: Service-Learning als Methode des hochschulischen Wissenstransfers
Creators: name: Czechowski, Katherine
Year: 2022

description: Die „dritte Mission“ beinhaltet die Öffnung der Hochschule für gesellschaftlich Relevantes, das in Kooperationen mit Praxisorganisationen anvisiert wird (Brandt et al. 2018). Campus-Community Partnerships ermöglichen einen wechselseitigen Wissenstransfer zwischen Hochschule und Praxis und führen zu einer perspektiven-reichen Auseinandersetzung mit praxisnahen Fragestellungen (Bringle/Hatcher 2002). Der Austausch von Wissen und Erfahrung liegt im Interesse nachhaltig angelegter Unternehmen und Hochschulen (Janger et al. 2017). Gelingende Transferleistungen ermöglichen ein wachsendes gegenseitiges Verständnis von Theorie und Praxis, die naturgemäß ineinander verwoben sind. Überdies lassen sie die Entstehung von Innovationsprozessen zu, die allen beteiligten Parteien nutzen (de Wit-de Vries et al. 2018). Innovative und disziplinunabhängige hochschuldidaktische Ansätze wie Service-Learning verfolgen eben diese ganzheitlichen Ziele, so dass die „Theorie auch ankommt“ (Augustin et al. 2015). Das studentische Engagement zeichnet Service-Learning aus und ergänzt den Ansatz um eine gesellschaftlich relevante Komponente. Die kritische Auseinandersetzung mit dem gesellschaftspolitischen Anspruch, den Service-Learning erhebt und das Ergründen der methodischen Umsetzung durch Hochschullehrende liegt im Interesse der Theorie (Hochschule) und der Praxis (Gesellschaft). Eine literaturgestützte Auseinandersetzung mit den Themenbereichen Service-Learning und Wissenstransfer ordnet den Lehr- und Lernansatz als eine praxisnahe Methode ein, die zunehmend an Bedeutung gewinnt und unter gewissen Voraussetzungen – wie Austauschbereitschaft der Beteiligten – einen Transfer mit der Praxis ermöglicht (Resch/Slepcevic-Zach 2021). Die Ergebnisse aus zwei qualitativen Fokusgruppendiskussionen mit insgesamt N=13 Lehrenden aus fünf österreichischen Hochschulen zeigen die Bedeutung der Lehrenden für Transferprozesse im Service-Learning. Die Inhaltsanalyse deckt implizite Wissensinhalte der Lehrenden, Studierenden und Praxispartner*innen und verschiedene Arten von Wissenstransfer (Externalisierung, Internalisierung und Kombination) im Service-Learning auf.
Effect of Doping on the phase stability and Superconductivity in LaH10
Creators: name: Wu, Zepeng
name: Sun, Yang
name: Durajski, Artur P.
name: Zheng, Feng
name: Antropov, Vladimir
name: Ho, Kai-Ming
name: Wu, Shunqing
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a computational investigation into the effects of chemical doping with 15 different elements on phase stability and superconductivity in the LaH10 structure. Most doping elements were found to induce softening of phonon modes, enhancing electron-phonon coupling and improving critical superconducting temperature while weakening dynamical stability. Unlike these dopants, Ce was found to extend the range of dynamical stability for LaH10 by eliminating the van Hove singularity near the Fermi level. The doped compound, La0.75Ce0.25H10, maintains high-temperature superconductivity. We also demonstrate that different Ce doping configurations in the LaH10 structure have a minimal effect on energetic stability and electron-phonon coupling strength. Our findings suggest that Ce is a promising dopant to stabilize LaH10 at lower pressures while preserving its high-temperature superconductivity.
Neutrino Oscillations With Recently Measured Sterile-Active Neutrino Mixing Angle
Creators: name: Kisslinger, Leonard S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: This brief report is an extension of a prediction of neutrino oscillation with a sterile neutrino using parameters of the sterile neutrino mass and mixing angle recently extracted from experiment.
description: 4 pages, 1 figure
Fiber breakage modeling based on hydrodynamic forces in macroscopic process simulations
Creators: name: Wittemann, Florian
name: Maertens, Robert
name: Henning, Frank
name: Kärger, Luise
Publisher: name: École Polytechnique Fédérale de Lausanne (EPFL)
Year: 2022
Subjects: Discontinuous fiber reinforced polymers
injection molding simulation
hydrodynamic forces
fiber breakage

description: Injection molding is one of the most important processes for manufacturing parts from discontinuous fiber reinforced polymers. Fiber length and orientation do not only influence the final structural behavior in an anisotropic way, but also the flow field and hence the mold filling process. Therefore, fiber length distribution and fiber breakage modeling are important aspects of an adequate process simulation. For fiber breakage modeling, hydrodynamic forces from matrix on fibers are considered within this work. Knowing the flow field and fiber orientation distributions of the homogenized material, flow-induced hydrodynamic forces on the fibers can be calculated. The fiber orientation tensor is used to determine reference fibers in every element. Based on this information an advanced approach for fiber breakage modelling is proposed. The fiber length distribution in the final part is compared to experimental data of a reactive injection molding process, showing good agreement.
title: Sestrička - Arbeitsmigration weiblichen Krankenpflegepersonals nach Österreich als ein femininer Aspekt des Transformationsprozesses nach 1989
Creators: name: Kerner, Elisabeth
Year: 2022

description: Diese Masterarbeit befasst sich vor dem Hintergrund der Migrationsgeschichte, und der Geschichte von Transformation mit dem Thema der weiblichen Arbeitsmigration (dauerhaft und zirkulär) von der Slowakei nach Österreich. Um die Tätigkeitsbereiche der Krankenpflegepersonen einzugrenzen, wird sich in dieser Masterarbeit auf Spitäler beschränkt. Es wird der Zeitraum von 1989 bis zur vollen Arbeitnehmerfreizügigkeit 2011 bearbeitet - ausgehend auch von einer politischen Kontextualisierung (wie etwa der Regulierung des Aufenthalts und Fremdenrechtsgesetz in Österreich) zum Zeitpunkt der „Samtenen" Revolution und danach. Des Weiteren werden politische und historische Ereignisse in der Slowakei in diesem Zeitrahmen skizziert, sowie die Reformen und Strukturen des Gesundheitssystems. Die Quellenbasis für diese Masterarbeit bilden zwölf Oral History Interviews. Daraus resultierten verschiedene wiederkehrende Themenbereiche, welche im Anschluss daran im Detail aufgeschlüsselt werden.
description: In front of the background from the history of migration and the history of transformation, this Master’s Thesis deals with the topic of female labor migration (permanent and circular) from Slovakia to Austria. In order to limit the fields of activity of nurses, this Master’s Thesis focuses on hospitals. Processed is the period from 1989 to full freedom of movement for workers in 2011 - also based on a political contextualisation (such as the regulation of residence and the Aliens-Law in Austria) at the time of the "Velvet" Revolution and afterwards. Furthermore, political, and historical events in Slovakia in this period of time are outlined, as well as the reforms and structures of the health care system. The source for this Master's Thesis is formed by twelve Oral History interviews. This resulted in various recurring topics, which are then shown in detail.
Generic eigenstate preparation via measurement-based purification
Creators: name: Yan, Jia-shun
name: Jing, Jun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: It is not a general opinion that that a quantum system could be purified into a target eigenstate via repeated measurements on a coupled qubit rather than direct transitions in the Hamiltonian. The projective measurement on the ancillary qubit gives rise to the positive operator-valued measures on the system that can filter out the unwanted states except the target one. In application, we discuss the measurement-based entanglement purification by which maximally entangled states (Bell states and Greenberger-Horne-Zeilinger states) can be distilled from the maximally mixed states or separable states. We also demonstrate the significant acceleration of a stimulated Raman adiabatic passage assisted by similar measurements. Our scheme allows arbitrary eigenstate preparation and reveals efficiency in multipartite systems for subspace purification. It offers a promising and generic quantum-control framework enriching the functionalities of quantum measurement.
A search for ultra-light axions using precision cosmological data
Creators: name: Hlozek, Renée
name: Grin, Daniel
name: Marsh, David J. E.
name: Ferreira, Pedro G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Ultra-light axions (ULAs) with masses in the range 10^{-33} eV 10^{-24} eV, ULAs are indistinguishable from standard cold dark matter on the length scales probed, and are thus allowed by these data. For m < 10^{-32} eV, ULAs are allowed to compose a significant fraction of the dark energy.
description: 31 pages, 16 figures, 1 table, updated to have same figure line-types/language as version published in Phys. Rev. D, grammatical corrections made, references added, results unchanged
Modeling rationality to control self-organization of crowds: An environmental approach
Creators: name: Cristiani, Emiliano
name: Priuli, Fabio S.
name: Tosin, Andrea
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 35L65, 49N90, 49Q10, 91D10

description: In this paper we propose a classification of crowd models in built environments based on the assumed pedestrian ability to foresee the movements of other walkers. At the same time, we introduce a new family of macroscopic models, which make it possible to tune the degree of predictiveness (i.e., rationality) of the individuals. By means of these models we describe both the natural behavior of pedestrians, i.e., their expected behavior according to their real limited predictive ability, and a target behavior, i.e., a particularly efficient behavior one would like them to assume (for, e.g., logistic or safety reasons). Then we tackle a challenging shape optimization problem, which consists in controlling the environment in such a way that the natural behavior is as close as possible to the target one, thereby inducing pedestrians to behave more rationally than what they would naturally do. We present numerical tests which elucidate the role of rational/predictive abilities and show some promising results about the shape optimization problem.
Variability of interplanetary shock and associated energetic particle properties as a function of the time window around the shock
Creators: name: Moreland, Kimberly
name: Dayeh, Maher
name: Li, Gang
name: Farahat, Ashraf
name: Ebert, Rob
name: Desai, Mihir
Publisher: name: arXiv
Year: 2023
Subjects: subject: Space Physics (physics.space-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: We study the effect of sampling windows on derived shock and associated energetic storm particle (ESP) properties in 296 fast-forward interplanetary shocks using ACE measurements at 1 au between 02/1998 - 08/2013. We vary the time windows from 2-mins to 20-mins for the shock properties and from 2-mins to 540-mins for ESP properties. Variability is quantified by the median absolute deviation (MAD) statistic. We find that the magnetic, density, and temperature compression ratios vary from their median values by 17.03%, 20.05%, 25.91%, respectively; shock speed by 16.26%, speed jump by 45.46%, Alfvenic Mach number by 31.53%, and shock obliquity by 24.25%. Spectral indices in the 2-min to 540-min windows downstream of the shock vary from the median value of 1.79 by 26.05%, and by 30.53% from the 1.70 median value upstream of the shock. Similarity of ESP spectral indices upstream and downstream of the shock suggest that these ESP populations are likely locally accelerated at the shock. Furthermore, we find that for a moving sampling window around the shock, values for the density ratio hold for ~10-mins; the magnetic ratio and shock speed jump hold for ~30-mins, and ~60-mins, respectively. Fixing the upstream window to 2-mins and moving only in the downstream direction, then the density ratio holds for ~60-mins downstream, magnetic ratio for ~30-mins, and the shock speed jump holds for ~110-mins. Beyond these time windows, derived shock properties no longer representative of shock properties. These results provide constraints for modeling and forecasting efforts of shock and ESP-associated properties.
Search for new phenomena in the dijet mass distribution using $p-p$ collision data at $\sqrt{s}=8$ TeV with the ATLAS detector
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Dijet events produced in LHC proton--proton collisions at a center-of-mass energy $\sqrt{s}=8$ TeV are studied with the ATLAS detector using the full 2012 data set, with an integrated luminosity of 20.3 fb$^{-1}$. Dijet masses up to about 4.5 TeV are probed. No resonance-like features are observed in the dijet mass spectrum. Limits on the cross section times acceptance are set at the 95% credibility level for various hypotheses of new phenomena in terms of mass or energy scale, as appropriate. This analysis excludes excited quarks with a mass below 4.09 TeV, color-octet scalars with a mass below 2.72 TeV, heavy $W'$ bosons with a mass below 2.45 TeV, chiral ${W^\ast}$ bosons with a mass below 1.75 TeV, and quantum black holes with six extra space-time dimensions with threshold mass below 5.82 TeV.
description: 12 pages plus author list (25 pages total), 11 figures, 2 tables, submitted to Phys. Rev. D., All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2013-11/
Canted Antiferromagnetism in Polar MnSiN$_2$ with High Néel Temperature
Creators: name: Kautzsch, Linus
name: Georgescu, Alexandru B.
name: Puggioni, Danilo
name: Kent, Greggory
name: Taddei, Keith M.
name: Reilly, Aiden
name: Seshadri, Ram
name: Rondinelli, James M.
name: Wilson, Stephen D.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: MnSiN$_2$ is a transition metal nitride with Mn and Si ions displaying an ordered distribution on the cation sites of a distorted wurtzite-derived structure. The Mn$^{2+}$ ions reside on a 3D diamond-like covalent network with strong superexchange pathways. We simulate its electronic structure and find that the N anions in MnSiN$_2$ act as $σ$- and $π$-donors, which serve to enhance the N-mediated superexchange, leading to the high Néel ordering temperature of $T_N$ = 443 K. Polycrystalline samples of MnSiN$_2$ were prepared to reexamine the magnetic structure and resolve previously reported discrepancies. An additional magnetic canting transition is observed at $T_\mathrm{cant}$ = 433 K and the precise canted ground state magnetic structure has been resolved using a combination of DFT calculations and powder neutron diffraction. The calculations favor a $G$-type antiferromagnetic spin order with lowering to $Pc^\prime$. Irreducible representation analysis of the magnetic Bragg peaks supports the lowering of the magnetic symmetry. The computed model includes a 10$^\circ$ rotation of the magnetic spins away from the crystallographic $c$-axis consistent with measured powder neutron diffraction data modeling and a small canting of 0.6$^\circ$.
description: 9 pages, 6 figures
Fast optical cooling of a nanomechanical cantilever by a dynamical Stark-shift gate
Creators: name: Yan, Leilei
name: Zhang, Jian-Qi
name: Zhang, Shuo
name: Feng, Mang
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The efficient cooling of the nanomechanical resonators is essential to exploration of quantum properties of the macroscopic or mesoscopic systems. We propose such a laser-cooling scheme for a nanomechanical cantilever, which works even for the low-frequency mechanical mode and under weak cooling lasers. The cantilever is attached by a diamond nitrogen-vacancy center under a strong magnetic field gradient and the cooling is assisted by a dynamical Stark-shift gate. Our scheme can effectively enhance the desired cooling efficiency by avoiding the off-resonant and unexpected carrier transitions, and thereby cool the cantilever down to the vicinity of the vibrational ground state in a fast fashion.
description: 14 pages, 7 figures
StableVQA: A Deep No-Reference Quality Assessment Model for Video Stability
Creators: name: Kou, Tengchuan
name: Liu, Xiaohong
name: Sun, Wei
name: Jia, Jun
name: Min, Xiongkuo
name: Zhai, Guangtao
name: Liu, Ning
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Video shakiness is an unpleasant distortion of User Generated Content (UGC) videos, which is usually caused by the unstable hold of cameras. In recent years, many video stabilization algorithms have been proposed, yet no specific and accurate metric enables comprehensively evaluating the stability of videos. Indeed, most existing quality assessment models evaluate video quality as a whole without specifically taking the subjective experience of video stability into consideration. Therefore, these models cannot measure the video stability explicitly and precisely when severe shakes are present. In addition, there is no large-scale video database in public that includes various degrees of shaky videos with the corresponding subjective scores available, which hinders the development of Video Quality Assessment for Stability (VQA-S). To this end, we build a new database named StableDB that contains 1,952 diversely-shaky UGC videos, where each video has a Mean Opinion Score (MOS) on the degree of video stability rated by 34 subjects. Moreover, we elaborately design a novel VQA-S model named StableVQA, which consists of three feature extractors to acquire the optical flow, semantic, and blur features respectively, and a regression layer to predict the final stability score. Extensive experiments demonstrate that the StableVQA achieves a higher correlation with subjective opinions than the existing VQA-S models and generic VQA models. The database and codes are available at https://github.com/QMME/StableVQA.
description: Accepted by ACM MM'23
title: Threading the basket of knowledge:  the role of iwi and hapū management plans for natural hazard research design
Creators: name: Kaiser, Lucy H.
name: Saunders, Wendy S. A.
name: Taylor, L
Publisher: name: GNS Science
Year: 2020

description: The Ministry of Business, Innovation and Employment (MBIE) Vision Mātauranga policy has created a clear message for researchers in Aotearoa/New Zealand—that research conducted in Aotearoa New Zealand should recognise and support the “unlocking of the innovative potential of Māori for the benefit of all New Zealand” and be designed with a clear engagement pathway. However, there is still confusion amongst many researchers on where to begin when considering the Vision Mātauranga component of their research. Who are the tangata whenua of the area? What is their history? What are their priorities? How would they like to be engaged? These are some of the question’s researchers should be considering in order to produce more compelling and culturally-appropriate research proposals. Iwi and Hapū Management Plans (IHMPs) are legislated under the Resource Management Act 1991. They provide a desktop resource a researcher can use as a starting point to inform research and engagement with iwi and hapū. IHMPs are highly valuable documents for envisioning how specific research expertise may be of interest to iwi—they outline iwi or hapū priorities, they have environmental and resource-based objectives, methods, and actions. In addition, they often outline the preferred engagement process. Despite this, our research found that only 22% of natural hazard researchers surveyed used them in their research process. This report will outline some findings from three surveys evaluating the confidence of Crown Research Institutes and National Science Challenge researchers regarding Vision Mātauranga research policy, and if/how IHMPs are being used in the design and implementation of research projects. Some of the key themes that emerged from natural hazard researcher respondents at GNS Science was the low level of awareness that IHMPs exist and are accessible; a lack of natural hazard information in the plans; that the content of IHMPs were extremely variable; and surprise at the large number of IHMPs that were available. The report will conclude with a series of recommendations for researchers who are starting to engage with Vision Mātauranga principles. (auth)
Anisotropic Rashba splitting dominated by out-of-plane spin polarization in two-dimensional Janus $XA_{2}Y$ ($A$= Si, Sn, Ge; $X,Y$= Sb, Bi) with surface imperfection
Creators: name: Lukmantoro, Arif
name: Absor, Moh. Adhib Ulil
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The anisotropic Rashba effect allows for the manipulation of electron spins in a more precise and tunable manner since the magnitude of the Rashba splitting and orientation of the spin textures can be simply controlled by tuning the direction of the externally applied electric field. Herein, we predict the emergence of the anisotropic Rashba effect in the two-dimensional (2D) Janus $XA_{2}Y$ constructed from the group IV ($A$= Si, Sn, Ge) and group V ($X,Y$ = Sb, Bi) elements having trigonal prismatic structures but lacking in-plane mirror symmetry. Due to the lowering point group symmetry of the crystal, the Rashba spin splitting is enforced to becomes anisotropic around certain high symmetry points in the Brillouin zone and preserves the out-of-plane spin textures. We illustrate this behavior using density functional theory calculations supplemented with $\vec{k}\cdot\vec{p}$ analysis on the Janus SbSi$_{2}$Bi monolayer as a representative example. Specifically, we observed large and anisotropic Rashba splitting with prominence contribution of the out-of-plane spin textures in the conduction band minimum around the $M$ point and valence band maximum around the $Γ$ point. More importantly, the anisotropic spin splitting and out-of-plane spin polarization are sensitively affected by surface imperfections, depending on the concentration and configuration of the $X$ and $Y$ elements in the 2D Janus $XA_{2}Y$ surface. Our study offer the possibility to realize the present systems for spintronics applications.
description: 5 Figures, accepted in Physical Review Materials
Capacity Estimation for Vehicle-to-Grid Frequency Regulation Services with Smart Charging Mechanism
Creators: name: Lam, Albert Y. S.
name: Leung, Ka-Cheong
name: Li, Victor O. K.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Due to various green initiatives, renewable energy will be massively incorporated into the future smart grid. However, the intermittency of the renewables may result in power imbalance, thus adversely affecting the stability of a power system. Frequency regulation may be used to maintain the power balance at all times. As electric vehicles (EVs) become popular, they may be connected to the grid to form a vehicle-to-grid (V2G) system. An aggregation of EVs can be coordinated to provide frequency regulation services. However, V2G is a dynamic system where the participating EVs come and go independently. Thus it is not easy to estimate the regulation capacities for V2G. In a preliminary study, we modeled an aggregation of EVs with a queueing network, whose structure allows us to estimate the capacities for regulation-up and regulation-down, separately. The estimated capacities from the V2G system can be used for establishing a regulation contract between an aggregator and the grid operator, and facilitating a new business model for V2G. In this paper, we extend our previous development by designing a smart charging mechanism which can adapt to given characteristics of the EVs and make the performance of the actual system follow the analytical model.
description: 11 pages, Accepted for publication in IEEE Transactions on Smart Grid
remUCPS - rate equation model of upconversion dynamics including photonic structure effects
Creators: name: Hofmann, Clarissa Lea Maja
name: Eriksen, Emil Haldrup
name: Bläsi, Benedikt
name: Hallermann, Florian
name: Fischer, Stefan
name: Fröhlich, Benjamin
name: Gutmann, Johannes
name: Herter, Barbara
name: Löper, Philipp
name: Steinkemper, Heiko
name: Goldschmidt, Jan Christoph
Publisher: name: Fraunhofer-Gesellschaft
Year: 2020
Subjects: subject: Upconversion
subject: Rate equation model
subject: Photonic structure
subject: Erbium
subject: Bragg structure
subject: DDC::000 Informatik, Informationswissenschaft, allgemeine Werke::000 Informatik, Wissen, Systeme::005 Computerprogrammierung, Programme, Daten
subject: DDC::500 Naturwissenschaften und Mathematik::530 Physik::535 Licht, Infrarot- und Ultraviolettphänomene

description: The remUCPS library provides an object-oriented implementation of a rate equation model, describing the upconversion dynamics in the upconverter Erbium in the host crystal NaYF4. Additonally, the model features the effects of a photonic structure, currently implemented as a Bragg structure, on the upconversion dynamics. The local energy density is calculated via an implementation of the [transfer materix method](https://zenodo.org/record/1344878#.X3GOr3UzZhE). The local density of optical states is calculated using [MIT Photonic Bands](https://doi.org/10.1364/OE.8.000173). The change in upconversion dynamics due to these two photonic effects can be investigated using remUCPS. The remUCPS code has been developed at Fraunhofer Institute for Solar Energy Systems ISE (Germany). All publications that led up to the current version are listed below. The current version of the model is extensively described in [Hofmann, Eriksen et al. 2018] (https://doi.org/10.1364/OE.26.007537), as are the contributions of all prior publications. The code can be used and adapted by anyone wanting to simulate photonic effects on upconversion or also just an upconversion process on its own. Among the most important parameters that can be scanned in the rate equation model are the design wavelength of the Bragg structure, the excitation wavelength, the angle of incidence and the incident irradiance. Have fun playing around! Contact: clarissa.hofmann@ise.fraunhofer.de
The Impact of Formalization Assistance on Informality: Experimental evidence from Colombian mines
Creators: name: Saavedra Pineda, Santiago
Publisher: name: Universidad del Rosario
Year: 2023

description: Más del 60% de los empleados del mundo trabajan en la economía informal. Una de las razones por las que las empresas permanecen en la informalidad es la duración y el costo del proceso de formalización. En este documento exploro si ayudar en el proceso de formalización podría reducir la informalidad en el sector minero en Colombia. El estudio es un experimento controlado aleatorio con minas informales de carbón y oro. Después de dos años de tratamiento, el tratamiento de asistencia para la formalización no aumentó las tasas de formalización y la deserción fue alta. Sin embargo, el tratamiento aumentó los ingresos de los mineros pero no los gastos, lo que sugiere que los mineros están ahorrando más, posiblemente para los costos de titulación. La alta deserción y el tratamiento fallido resaltan las dificultades de formalizar el sector minero.
Trends in electronic structures and $s_{\pm}$-wave pairing for the rare-earth series in bilayer nickelate superconductor $R_ 3$Ni$_2$O$_7$
Creators: name: Zhang, Yang
name: Lin, Ling-Fang
name: Moreo, Adriana
name: Maier, Thomas A.
name: Dagotto, Elbio
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The recent discovery of pressure-induced superconductivity in the bilayer La$_3$Ni$_2$O$_7$ (LNO) has opened a new platform for the study of unconventional superconductors. In this publication, we investigate theoretically the whole family of bilayer 327-type nickelates $R_3$Ni$_2$O$_7$ ($R$ = Rare-earth elements) under pressure. From La to Lu, the lattice constants and volume decrease, leading to enhanced in-plane and out-of-plane hoppings, resulting in an effectively reduced electronic correlation $U/W$. Furthermore, the Ni's $t_{2g}$ states shift away from the $e_g$ states, while the crystal-field splitting between $d_{3z^2-r^2}$ and $d_{x^2-y^2}$ is almost unchanged. In addition, six candidates were found to become stable in the Fmmm phase, with increasing values of critical pressure as the atomic number increased. Similar to the case of LNO, the $s_{\pm}$-wave pairing tendency dominates in all candidates, due to the nesting between the {\bf M}=$(π,π)$ and the {\bf X}=$(π,0)$ and {\bf Y}=$(0,π)$ points in the Brillouin zone. Then, $T_c$ is expected to decrease as the radius of rare-earth (RE) ions decreases. Our results suggest that LNO is already the "optimal" candidate, with Ce a close competitor, among the whole RE bilayer nickelates, and to increase $T_c$ we suggest to grow on special substrates with larger in-plane lattice spacings.
description: Main text (9 pages, 5 figures)
Fear to Vote: Explosions, Salience, and Elections
Creators: name: Vargas Duque, Juan Fernando
name: Purroy, Miguel E.
name: Coy, Felipe
name: Perilla, Sergio
name: Prem, Mounu
Publisher: name: Universidad del Rosario
Year: 2023

description: Criminal groups use violence strategically to manipulate the behavior of victims and bystanders. At the same time, violence is a stimulus that causes fear, which also shapes people’s reactions. Taking advantage of the randomness in the timing of antipersonnel landmine accidents in Colombia, as well as their coordinates relative to those of voting polls, we identify the effect of violence-induced fear (independent from intentions) on electoral behavior. Fortuitous landmine explosions reduce political participation. We further disentangle whether the type of fear caused by landmine explosions responds to an information channel (whereby people learn about the risk of future victimization) or by the salience of the explosion (which causes individuals to make impulsive decisions, driven by survival considerations), and show evidence in favor of the latter. While the turnout reduction takes place across the ideological spectrum, we document that the explosions induce a shift in the political preferences of individuals who do vote. These findings point to worrisome potential consequences for the consolidation of democracies in places affected by conflict.
Explainable Machine Learning for Hydrogen Diffusion in Metals and Random Binary Alloys
Creators: name: Lu, Grace M.
name: Witman, Matthew
name: Agarwal, Sapan
name: Stavila, Vitalie
name: Trinkle, Dallas R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Hydrogen diffusion in metals and alloys plays an important role in the discovery of new materials for fuel cell and energy storage technology. While analytic models use hand-selected features that have clear physical ties to hydrogen diffusion, they often lack accuracy when making quantitative predictions. Machine learning models are capable of making accurate predictions, but their inner workings are obscured, rendering it unclear which physical features are truly important. To develop interpretable machine learning models to predict the activation energies of hydrogen diffusion in metals and random binary alloys, we create a database for physical and chemical properties of the species and use it to fit six machine learning models. Our models achieve root-mean-squared-errors between 98-119 meV on the testing data and accurately predict that elemental Ru has a large activation energy, while elemental Cr and Fe have small activation energies. By analyzing the feature importances of these fitted models, we identify relevant physical properties for predicting hydrogen diffusivity. While metrics for measuring the individual feature importances for machine learning models exist, correlations between the features lead to disagreement between models and limit the conclusions that can be drawn. Instead grouped feature importances, formed by combining the features via their correlations, agree across the six models and reveal that the two groups containing the packing factor and electronic specific heat are particularly significant for predicting hydrogen diffusion in metals and random binary alloys. This framework allows us to interpret machine learning models and enables rapid screening of new materials with the desired rates of hydrogen diffusion.
description: 36 pages, 8 figures, supplemental material
On a nonlocal model of non-isothermal phase separation
Creators: name: Gajewski, Herbert
Publisher: name: Weierstrass Institute
Year: 2001
Subjects: subject: Coupled Cahn-Hilliard equations
subject: binary alloys
subject: segregation model
subject: nonlocal interaction
subject: free energy
subject: entropy
subject: Onsager relations
subject: initial boundary value problem
subject: global existence and uniqueness
subject: Lyapunov function
subject: asymptotic behaviour
subject: 35K45
subject: 35K57
subject: 35B40
subject: 80A20
subject: 80A22

description: A nonlocal model of non-isothermal phase separation in binary alloys is presented. The model is deduced from a free energy with a nonconvex part taking into account nonlocal particle interaction. The model consists of a system of second order parabolic evolution equations for heat and mass, coupled by nonlinear drift terms and a state equation which involves a nonlocal interaction potential. The negative entropy turns out to be Lyapunov functional of the system and yields the key estimate for proving global existence and uniqueness results and for analyzing the asymptotic behaviour as time goes to infinity.
Counterintuitive properties of the fixation time in network-structured populations
Creators: name: Hindersin, Laura
name: Traulsen, Arne
Publisher: name: arXiv
Year: 2014
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Evolutionary dynamics on graphs can lead to many interesting and counterintuitive findings. We study the Moran process, a discrete time birth-death process, that describes the invasion of a mutant type into a population of wild-type individuals. Remarkably, the fixation probability of a single mutant is the same on all regular networks. But non-regular networks can increase or decrease the fixation probability. While the time until fixation formally depends on the same transition probabilities as the fixation probabilities, there is no obvious relation between them. For example, an amplifier of selection, which increases the fixation probability and thus decreases the number of mutations needed until one of them is successful, can at the same time slow down the process of fixation. Based on small networks, we show analytically that (i) the time to fixation can decrease when links are removed from the network and (ii) the node providing the best starting conditions in terms of the shortest fixation time depends on the fitness of the mutant. Our results are obtained analytically on small networks, but numerical simulations show that they are qualitatively valid even in much larger populations.
title:  The Role of Creditors in Corporate and Contract Governance
Creators: name: Sica, Tommaso
Publisher: name: Roma TrE-Press
Year: 2022

description: The essay deals with the impact on corporate and contract governance of creditor’s intervention in the management of the financed company. In fact, the conventional notion according to which the creditor was not endowed with sufficient incentives to manage the company has gradually been overcome since the development of new contractual types that grant the lender conformative rights in the debtor company. By contrast, the contribution from the creditor might enforce both the entity’s commercial operations and, in general, the market structures in which the debtor company participates.
description: Roma Tre Law Review – 01/2022
Negative Income Shocks, COVID, and Trust
Creators: name: Aycinena Abascal, Diego
name: Blanco, Mariana
Publisher: name: Universidad del Rosario
Year: 2023

description: In this paper we report results from an online experiment conducted with over 1, 000 participants from Colombia’s general population. The experiment is de- signed to examine the impact of exposition to a COVID priming and a negative economic shock on trusting behavior. Overall, we find that participants under the neutral prime who are exposed to a negative economic shock become less trusting. In addition, we find that trustors who receive the shock become more trusting, increasing the proportion of the endowment they transfer. This re- sult is not an artifact of the modification of the trsutor’s action set due to the negative shock received, and is consistent with beliefs of higher returned amount and stronger normative expectations of reciprocity, as well as general pro-sociality.
Digital Ecology: Coexistence and Domination among Interacting Networks
Creators: name: Kleineberg, Kaj-Kolja
name: Boguñá, Marián
Publisher: name: arXiv
Year: 2014
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The overwhelming success of the web 2.0, with online social networks as key actors, has induced a paradigm shift in the nature of human interactions. The user-driven character of these services for the first time has allowed researchers to quantify large-scale social patterns. However, the mechanisms that determine the fate of networks at a system level are still poorly understood. For instance, the simultaneous existence of numerous digital services naturally raises the question under which conditions these services can coexist. In analogy to population dynamics, the digital world is forming a complex ecosystem of interacting networks whose fitnesses depend on their ability to attract and maintain users' attention, which constitutes a limited resource. In this paper, we introduce an ecological theory of the digital world which exhibits a stable coexistence of several networks as well as the domination of a single one, in contrast to the principle of competitive exclusion. Interestingly, our model also predicts that the most probable outcome is the coexistence of a moderate number of services, in agreement with empirical observations.
Towards Intense Ultra-Broadband High Repetition Rate Terahertz Sources Based on Organic Crystals [Invited]
Creators: name: Mansourzadeh, Samira
name: Vogel, Tim
name: Omar, Alan
name: Buchmann, Tobias O.
name: Kelleher, Edmund J. R.
name: Jepsen, Peter U.
name: Saraceno, Clara J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Increasing the average power of broadband, few-cycle terahertz (THz) sources is currently a topic of intense investigation, fueled by recent immense progress in high average power femtosecond laser driving sources at 1030 nm. However, many crucial applications would benefit not only from an increase in average power, but also from ultra-broad bandwidth, while maintaining high dynamic range at these frequencies. This calls for the challenging combination of high repetition rates and high average power simultaneously. Here, we discuss the recent progress in the promising approach enabled by organic crystals for THz-generation. Specifically, this review article discusses advances with the most commonly used organic crystals BNA, DAST, DSTMS, OH1 and HMQ-TMS. We place special emphasis on nonlinear and thermal properties and discuss future directions for this field.
title: Historisches Lernen und Serious Games - direkte und non-instruktionale Lernprozesse am Beispiel von "Valiant Hearts: the Great War"
Creators: name: Barth, Maximilian
Year: 2022

description: Diese Arbeit beschäftigt sich mit dem Thema historisches Lernen mit Videospielen bei SchülerInnen einer vierten Klasse BHS. Ziel war die durch das Spielen in Gang gesetzten Lernprozesse zu dokumentieren und zu analysieren. Dazu wurde folgende Forschungsfrage gestellt: Welche direkten und/oder non-instruktionalen Lernprozesse werden durch das Spiel Valiant Hearts: The Great War bei Lernenden ausgelöst? Um die Forschungsfrage zu beantworten, wurde eine qualitative Studie durchgeführt, welche sich aus einem Prä-Fragebogen, einer Spielsequenz, eines Post-Fragebogens sowie einer Gruppendiskussion auseinandersetzte. Durch diese empirische Studie konnten Lernprozesse im Bereich Reproduktion, Transfer und Reflexion auf non-instruktionaler Ebene nachgewiesen werden. Die beobachteten Lernprozesse im Transferbereich waren aber nicht nur positiv zu bewerten, da diese oft die unreflektierte Übernahme von Spielinszenierungen umfassten. Dies zeigt, dass selbst das Spielen von Serious Games ohne didaktische Einbettung nur bedingt zielführend ist.