cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Modal-set estimation with an application to clustering
Creators: name: Jiang, Heinrich
name: Kpotufe, Samory
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: We present a first procedure that can estimate -- with statistical consistency guarantees -- any local-maxima of a density, under benign distributional conditions. The procedure estimates all such local maxima, or $\textit{modal-sets}$, of any bounded shape or dimension, including usual point-modes. In practice, modal-sets can arise as dense low-dimensional structures in noisy data, and more generally serve to better model the rich variety of locally-high-density structures in data. The procedure is then shown to be competitive on clustering applications, and moreover is quite stable to a wide range of settings of its tuning parameter.
Long-term monitoring of Ark 120 with Swift
Creators: name: Gliozzi, M.
name: Papadakis, I. E.
name: Grupe, D.
name: Brinkmann, W. P.
name: Raeth, C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the results of a six-month Swift monitoring campaign of Ark120, a prototypical bare Seyfert1 galaxy. The lack of intrinsic absorption combined with the nearly contemporaneous coverage of the UV and X-ray bands makes it possible to investigate the link between the accretion disk and the Comptonization corona. Our observations confirm the presence of substantial temporal variability, with the X-rays characterized by large-amplitude flux changes on timescales of few days, while the variations in the UV bands are smoother on timescales of several weeks. The source also shows spectral variability with the X-ray spectrum steepening when the source is brighter. We do not detect any correlation between the UV flux and the X-ray spectral slope. A cross correlation analysis suggests positive delays between X-rays and the UV emission, favoring a scenario of disk reprocessing. Although the strength of the correlation is moderate with a delay not well constrained (7.5+-7 days), it is nevertheless indicative of a large disk reprocessing region, with a separation between the X-ray and the UV emitting regions of the order of 1000 rG. The Ark120 correlation results are in agreement with those obtained in similar monitoring studies. When combined together, the observations can be well described by a linear relation between the X-ray/UV delay and the black hole mass. Within the context of the simplest scenario where these delays correspond to light-travel times, the implied distance between the X-ray source and the UV disk reprocessing region is of the order of many hundreds of gravitational radii.
description: 11 pages, 11 figures, 4 tables, accepted for publication in MNRAS
Field-Induced Partial Disorder in a Shastry-Sutherland Lattice
Creators: name: Marshall, Madalynn
name: Billingsley, Brianna R.
name: Bai, Xiaojian
name: Ma, Qianli
name: Kong, Tai
name: Cao, Huibo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A 2-Q antiferromagnetic order of the ferromagnetic dimers was found below TN = 2.9 K in the Shastry-Sutherland lattice BaNd2ZnS5 by single crystal neutron diffraction. The magnetic order can be understood by the orthogonal arrangement of local Ising Nd spins, identified by polarized neutrons. A field was applied along [1 -1 0] to probe the observed metamagnetic transition in the magnetization measurement. The field decouples two magnetic sublattices corresponding to the propagation vectors q1= (0.5, 0.5, 0) and q2= (-0.5, 0.5, 0), respectively. Each sublattice shows a stripe order with a Neel-type arrangement in each single layer. The stripe order with q1 remains nearly intact up to 6 T, while the other one with q2 is suppressed at a critical field Hc ~1.7 T, indicating a partial disorder. The Hc varies with temperature and is manifested in the H-T phase diagram constructed by measuring the magnetization in BaNd2ZnS5.
description: 25 pages, 6 figures
Family of binary transition metal pnictide superconductors
Creators: name: Liao, Zheng-Wei
name: Yi, Xin-Wei
name: You, Jing-Yang
name: Gu, Bo
name: Su, Gang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Superconductivity in transition metal nitrides (TMNs) has been investigated for a long time, such as zirconium nitride (ZrN) with a superconducting transition temperature Tc of 10 K. Recently, a phase diagram has been revealed in ZrNx with different nitrogen concentrations, which is very similar to that of high-temperature copper oxide superconductors. Here, we study the TMNs with face-centered cubic lattice, where ZrN and HfN have been experimentally obtained, and predict eight new stable superconductors by the first-principle calculations. We find that CuN has a high Tc of 30 K with a very strong electron-phonon coupling (EPC) strength. In contrast to ZrN, CuN has softening acoustic phonons at the high symmetry point L, which accounts for its much stronger EPC. In addition, the highly symmetrical structure leads to topological protected nodal points and lines, such as the hourglass Weyl loop in kx/y/z = 0 plane and Weyl points in kx/y/z = 2π/a plane, as well as quadratic band touch at Γ point. CuN could be a topological superconductor. Our results expand the transition metal nitrides superconductor family and would be helpful to guide the search for high temperature topological superconductors.
description: 5 pages, 4 figures, 2 tables
Excitation and probing of low-energy nuclear states at high-energy storage rings
Creators: name: Jin, Junlan
name: Bekker, Hendrik
name: Kirschbaum, Tobias
name: Litvinov, Yuri A.
name: Pálffy, Adriana
name: Sommerfeldt, Jonas
name: Surzhykov, Andrey
name: Thirolf, Peter G.
name: Budker, Dmitry
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: Accelerator Physics (physics.acc-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: $^{229}$Th with a low-lying nuclear isomeric state is an essential candidate for a nuclear clock as well as many other applications. Laser excitation of the isomeric state has been a long-standing goal. With relativistic $^{229}$Th ions in storage rings, high-power lasers with wavelengths in the visible range or longer can be used to achieve high excitation rates of $^{229}$Th isomers. This can be realized through direct resonant excitation, or excitation via an intermediate nuclear or electronic state, facilitated by the tunability of both the laser-beam and ion-bunch parameters. Unique opportunities are offered by highly charged $^{229}$Th ions due to the nuclear-state mixing. The significantly reduced isomeric-state lifetime corresponds to a much higher excitation rate for direct resonant excitation. Importantly, we propose electric dipole transitions changing both the electronic and nuclear states that are opened by the nuclear hyperfine mixing. We suggest using them for efficient isomer excitation in Li-like $^{229}$Th ions, via stimulated Raman adiabatic passage or single-laser excitation. We also propose schemes for probing the isomers, utilizing nuclear radiative decay or laser spectroscopy on electronic transitions, through which the isomeric-state energy can be determined with an orders-of-magnitude higher precision than the current value. The schemes proposed here for $^{229}$Th could also be adapted to low-energy nuclear states in other nuclei, such as $^{229}$Pa.
description: 20+7 pages, 12 figures
Sampled-data control design for systems with quantized actuators
Creators: name: Ferrante, Francesco
name: Tarbouriech, Sophie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper deals with the problem of designing a sampled-data state feedback control law for continuous-time linear control systems subject to uniform input quantization. The sampled-data state feedback is designed to ensure the uniform global asymptotic stability (UGAS) of an attractor surrounding the origin. The closed-loop system is rewritten as a hybrid dynamical system. To do this, an auxiliary clock variable triggering the occurrence of sampling events is introduced. A numerically tractable algorithm with feasibility guarantees, based on concave-convex decomposition, is then proposed allowing to minimize the size of the attractor. Theoretical results are illustrated in a numerical example.
description: Extended version of the paper accepted for presentation at the 8th IFAC Symposium on System Structure and Control (SSSC). V2 and V3 fix some (minor) typos in the published version
How Adventurers Become Tourists:
Creators: name: Mittag, Jürgen
name: Wendland, Diana
Publisher: name: Leipziger Universitätsverlag
Year: 2014

description: Ziel des Beitrags ist es, Perspektiven einer stärkeren inhaltlichen und konzeptionellen Verzahnung der Forschungen zum alternativen Tourismus und zum Ferntourismus am Beispiel der Bundesrepublik Deutschland aufzuzeigen. Alternativ- und Ferntourismus weisen sowohl Sonderheiten als auch Schnittmengen auf: Im Bestreben, sich von einer zunehmend raumgreifenden Massenreisekultur abzugrenzen, rückten namentlich in den 1970er und 1980er Jahren ferne außereuropäische Ziele ins Visier von unkonventionellen Touristen. Als Entdecker, Forscher oder Pioniere bereisten sie auf individuellen Pfaden die Fremde, erweiterten dabei kontinuierlich den touristischen Radius und wurden schließlich selbst zu „touristischen“ Touristen. Der alternative Reiseanspruch dieser frühen Fernreisenden sowie die vermeintliche Standardisierung des alternativen Ferntourismus werden im vorliegenden Beitrag exemplarisch anhand von alternativen Fernreiseführern, die ursprünglich im Selbstverlag publiziert wurden, untersucht. Am Beispiel dieses bislang noch unerforschten Quellenkorpus können sowohl Wahrnehmungs- als auch Differenzierungsprozesse des alternativen Ferntourismus sowie das Verhältnis und die Wechselwirkungen von Alternativ- und Massentourismus analysiert werden.
description: Comparativ, Vol 24 No 2 (2014): Between Leisure, Work and Study: Tourism and Mobility in Europe from 1945-1989
Deep Reinforcement Learning for Orchestrating Cost-Aware Reconfigurations of vRANs
Creators: name: Murti, Fahri Wisnu
name: Ali, Samad
name: Iosifidis, George
name: Latva-aho, Matti
Publisher: name: arXiv
Year: 2022
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Virtualized Radio Access Networks (vRANs) are fully configurable and can be implemented at a low cost over commodity platforms to enable network management flexibility. In this paper, a novel vRAN reconfiguration problem is formulated to jointly reconfigure the functional splits of the base stations (BSs), locations of the virtualized central units (vCUs) and distributed units (vDUs), their resources, and the routing for each BS data flow. The objective is to minimize the long-term total network operation cost while adapting to the varying traffic demands and resource availability. Testbed measurements are performed to study the relationship between the traffic demands and computing resources, which reveals high variance and depends on the platform and its load. Consequently, finding the perfect model of the underlying system is non-trivial. Therefore, to solve the proposed problem, a deep reinforcement learning (RL)-based framework is proposed and developed using model-free RL approaches. Moreover, the problem consists of multiple BSs sharing the same resources, which results in a multi-dimensional discrete action space and leads to a combinatorial number of possible actions. To overcome this curse of dimensionality, action branching architecture, which is an action decomposition method with a shared decision module followed by neural network is combined with Dueling Double Deep Q-network (D3QN) algorithm. Simulations are carried out using an O-RAN compliant model and real traces of the testbed. Our numerical results show that the proposed framework successfully learns the optimal policy that adaptively selects the vRAN configurations, where its learning convergence can be further expedited through transfer learning even in different vRAN systems. It offers significant cost savings by up to 59\% of a static benchmark, 35\% of DDPG with discretization, and 76\% of non-branching D3QN.
description: This article has been accepted for publication in IEEE Transactions on Network and Service Management
‘Like Sheep’?
Creators: name: Tondera, Benedikt
Publisher: name: Leipziger Universitätsverlag
Year: 2014

description: Die Einführung des von der UdSSR ausgehenden Auslandstourismus im Zuge der Chruščevschen Tauwetterpolitik bescherte den sowjetischen Autoritäten eine Reihe schwieriger Fragen: Wie ließen sich Bürger finden, die die Sowjetunion im Ausland würdig vertreten würden, wie konnten die Touristen während der Reise unter Kontrolle gehalten werden, und wie konnten Auslandsreisen propagandistisch genutzt werden? Vor dem Hintergrund dieser Fragen betrieben die staatlichen sowjetischen Tourismusorganisationen einen beträchtlichen Aufwand, um Auslandsreisen zu einem kontrollierbaren Element der Kulturdiplomatie zu formen. Der vorliegende Artikel befasst sich in diesem Kontext mit Momenten, in denen die Kontrollmechanismen zeitweilig nicht mehr griffen, etwa wenn Touristen aus den erwarteten Verhaltensmustern ausbrachen oder Mängel in der Reiseorganisation den reibungslosen Ablauf der Auslandsfahrten störten. Derartige Vorfälle waren mehr als nur Unregelmäßigkeiten in einer ansonsten geölten Inszenierungsmaschinerie – sie verwiesen auf strukturelle Probleme des Auslandstourismus, eines wichtigen Elementes der Außendarstellung in Zeiten des Kalten Krieges.
description: Comparativ, Vol 24 No 2 (2014): Between Leisure, Work and Study: Tourism and Mobility in Europe from 1945-1989
Flat $GL(1|1)$-connections and fatgraphs
Creators: name: Bourque, Andrea
name: Zeitlin, Anton M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Geometric Topology (math.GT)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We study the moduli space of flat $GL(1|1)$-connections on a punctured surface from the point of view of graph connections. To each fatgraph, a system of coordinates is assigned, which involves two bosonic and two fermionic variables per edge, subject to certain relations. In the case of trivalent graphs, we provide a closed explicit formula for the Whitehead moves. In addition, we discuss the invariant Poisson bracket.
description: v2: 13 pages, minor revisions
Formation of hypernuclei in evaporation and fission processes
Creators: name: Botvina, A. S.
name: Buyukcizmeci, N.
name: Ergun, A.
name: Ogul, R.
name: Bleicher, M.
name: Pochodzalla, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: There are excellent opportunities to produce excited heavy hyper residues in relativistic hadron and peripheral heavy-ion collisions. We investigate the disintegration of such residues into hyper nuclei via evaporation of baryons and light clusters and their fission. Previously these processes were well known for normal nuclei as the decay channels at low excitation energies. We have generalized these models for the case of hyper-matter. In this way we make extension of nuclear reaction studies at low temperature into the strange sector. We demonstrate how the new decay channels can be integrated in the whole disintegration process. Their importance for mass and isotope distributions of produced hyper-fragments is emphasized. New and exotic isotopes obtained within these processes may provide a unique opportunity for investigating hyperon interaction in nuclear matter.
description: 32 pages, 13 figures, accepted to Phys. Rev. C
Magnetotropic susceptibility
Creators: name: Shekhter, A.
name: McDonald, R. D.
name: Ramshaw, B. J.
name: Modic, K. A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The magnetotropic susceptibility is the thermodynamic coefficient associated with the rotational anisotropy of the free energy in an external magnetic field, and is closely related to the magnetic susceptibility. It emerges naturally in frequency-shift measurements of oscillating mechanical cantilevers, which are becoming an increasingly important tool in the quantitative study of the thermodynamics of modern condensed matter systems. Here we discuss the basic properties of the magnetotropic susceptibility as they relate to the experimental aspects of frequency-shift measurements, as well as to the interpretation of those experiments in terms of the intrinsic properties of the system under study.
The growth and nature of alternative dispute resolution in Australian workplaces
Creators: name: Van Gramberg., Bernadine
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Book Review of Susan Greenfield's 'Mind Change: How Digital Technologies Are Leaving Their Mark On Our Brains'
Creators: name: Davies, Todd
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences
subject: H.1.2; K.4.1

description: This is a review of Susan Greenfield's 2015 book 'Mind Change: How Digital Technologies Are Leaving Their Mark On Our Brains'. Greenfield is a neuroscientist and a member of the UK House of Lords, who argues that digital technologies are changing the human environment "in an unprecedented way," and that by adapting to this environment, "the brain may also be changing in an unprecedented way." The book and its author have created a surprising amount of controversy. I discuss both Greenfield's book and a prominent critique by Bell et al. (2015). The exchange points to some flaws in Greenfield's argument and represents an interesting debate about the public role of scientists, but it does not undermine the value of the book as a springboard for discussions about possible policies and future research.
description: 5 pages, no figures
Study of tunneling radiation and thermal fluctuations of a gauge super gravity like black hole
Creators: name: Ali, Riasat
name: Asgher, Muhammad
name: Sahoo, P. K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Newman-Janis technique and the semi-classical Hamilton-Jacobi approach are two distinct phenomena that we apply in this paper to examine the Hawking temperature $(T_{H})$ for $4$-dimensional gauge super gravity like black hole with rotation parameters. First, using the Newman-Janis algorithmic approach, we compute the gauge super gravity like black holes solution. We use surface gravity to derive the $T_H$ for a gauge super gravity like black hole. In order to do this, we use the Lagrangian field equation in the background of generalized uncertainty principle, semi-classical Hamilton-Jacobi approach and the WKB approximation technique. Furthermore, we investigate the stability of considered geometry with the help of corrected entropy and well known thermodynamic quantities. It is concluded that the gauge super gravity like black holes is stable under first-order corrections.
description: Annals of Physics published version
The ELIXIR Cloud
Creators: name: Community, The ELIXIR Cloud
Publisher: name: F1000 Research Limited
Year: 2020

description: The ELIXIR Cloud and Authentication & Authorisation Infrastructure (AAI) platform aims to leverage a coordinated network of ELIXIR Nodes to deliver a Global Alliance for Genomic Health (GA4GH) standards-compliant federated environment to enable large scale genomic & phenotypic data analysis across international boundaries. The poster showcases the individual services and their state of integration into the ELIXIR Cloud Stack. The alignment with ELIXIR Platforms and Communities and future milestones are highlighted.
Thickness characterization of atomically-thin WSe$_2$ on epitaxial graphene by low-energy electron reflectivity oscillations
Creators: name: de la Barrera, Sergio C.
name: Lin, Yu-Chuan
name: Eichfeld, Sarah M.
name: Robinson, Joshua A.
name: Gao, Qin
name: Widom, Michael
name: Feenstra, Randall M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this work, low-energy electron microscopy is employed to probe structural as well as electronic information in few-layer WSe$_2$ on epitaxial graphene on SiC. The emergence of unoccupied states in the WSe$_2$--graphene heterostructures are studied using spectroscopic low-energy electron reflectivity. Reflectivity minima corresponding to specific WSe$_2$ states that are localized between the monolayers of each vertical heterostructure are shown to reveal the number of layers for each point on the surface. A theory for the origin of these states is developed and utilized to explain the experimentally observed featured in the WSe$_2$ electron reflectivity.
description: 15 pages, 7 figures
Simultaneous Measurement of Resistively and Optically Detected Nuclear Magnetic Resonance in the $ν=2/3$ Fractional Quantum Hall Regime
Creators: name: Akiba, K.
name: Nagase, K.
name: Hirayama, Y.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We observe nuclear magnetic resonance (NMR) in the fractional quantum Hall regime at Landau level filling factor $ν=2/3$ from simultaneous measurement of longitudinal resistance and photoluminescence (PL). The dynamic nuclear spin polarization is induced by applying a huge electronic current at the spin phase transition point of $ν=2/3$. The NMR spectra obtained from changes in resistance and PL intensity are qualitatively the same; that is, the Knight shift (spin polarized region) and zero-shift (spin unpolarized region) resonances are observed in both. The observed change in PL intensity is interpreted as a consequence of the trion scattering induced by polarized nuclear spins. We conclude that both detection methods probe almost the same local phenomena.
Pub2Tools: a utility constructing bio.tools entries from publications
Creators: name: Jaaniso, Erik
name: Ienasescu, Hans
name: Salumets, Ahto
name: Ison, Jon
name: Peterson, Hedi
Publisher: name: F1000 Research Limited
Year: 2020

description: Pub2Tools is a Java command-line tool that looks through the scientific literature available in Europe PMC and constructs entry candidates for the bio.tools software registry from suitable publications. Pub2Tools automates a lot of the process needed for growing bio.tools, though its results still need some manual curation before they are of satisfactory quality. Running Pub2Tools once per month would result in hundreds of new metadata entries of tools, databases and services published in bioinformatics and life sciences journals.

First, Pub2Tools gets a list of all publications available for the given period. After this initial list is narrowed down by combinations of keyphrases, the contents of the remaining publications are downloaded and the abstract of each publication is mined for the potential tool name. Names are assigned confidence scores, with low confidence publications often not being suitable for bio.tools at all. In addition to the tool name, web links matching the name are extracted from the abstract and full text of a publication and divided to the homepage and other link attributes of bio.tools. The content of publications and extracted links is also mined for software license and programming language information and phrases for the tool description attribute are automatically constructed. Good enough results are chosen for inclusion to bio.tools. In addition to finding new content for bio.tools, Pub2Tools can also be used to improve the current content when run on existing entries of bio.tools.

For downloading publications and links, Pub2Tools uses a complementary tool developed by the authors, called PubFetcher. PubFetcher is capable of fetching publications from many other resources besides Europe PMC. And in case of web pages, it can extract metadata from standard sites like code repositories. Once the information about tools is obtained by Pub2Tools, another tool -- called EDAMmap -- is used for automatically adding EDAM ontology annotations to the new bio.tools entries. Thus, the full toolset can be used to identify, obtain and annotate public domain information about bioinformatics tools and databases in an interoperable manner.

Pub2Tools is free and open-source software available from https://github.com/bio-tools/pub2tools, with the documentation at https://pub2tools.readthedocs.io/.
Strange correlators for topological quantum systems from bulk-boundary correspondence
Creators: name: Lepori, Luca
name: Burrello, Michele
name: Trombettoni, Andrea
name: Paganelli, Simone
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: "Strange" correlators provide a tool to detect topological phases arising in many-body models by computing the matrix elements of suitably defined two-point correlations between the states under investigation and trivial reference states. Their effectiveness depends on the choice of the adopted operators. In this paper we give a systematic procedure for this choice, discussing the advantages of choosing operators using the bulk-boundary correspondence of the systems under scrutiny. Via the scaling exponents, we directly relate the algebraic decay of the strange correlators with the scaling dimensions of gapless edge modes operators. We begin our analysis with lattice models hosting symmetry-protected topological phases and we analyze the sums of the strange correlators, pointing out that integrating their moduli substantially reduces cancellations and finite-size effects. We also analyze instances of systems hosting intrinsic topological order, as well as strange correlators between states with different nontrivial topologies. Our results for both translational and non-translational invariant cases, and in presence of on-site disorder and long-range couplings, extend the validity of the strange correlators approach for the diagnosis of topological phases of matter, and indicate a general procedure for their optimal choice.
description: 28 pages, 10 figures
Hydrogen atom in a Laser-Plasma
Creators: name: Falaye, Babatunde James
name: Sun, Guo-Hua
name: Liman, Muhammed S.
name: Oyewumi, K. J.
name: Dong, Shi-Hai
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We scrutinize the behaviour of hydrogen atom's eigenvalues in a quantum plasma as it interacts with electric field directed along $θ=π$ and exposed to linearly polarized intense laser field radiation. Using the Kramers-Henneberger (KH) unitary transformation, which is semiclassical counterpart of the Block-Nordsieck transformation in the quantized field formalism, the squared vector potential that appears in the equation of motion is eliminated and the resultant equation is expressed in KH frame. Within this frame, the resulting potential and the corresponding wavefunction have been expanded in Fourier series and using Ehlotzky's approximation, we obtain a laser-dressed potential to simulate intense laser field. By fitting the exponential-cosine-screened Coulomb potential into the laser-dressed potential, and then expanding it in Taylor series up to $\mathcal{O}(r^4,α_0^9)$, we obtain the eigensolution (eigenvalues and wavefunction) of hydrogen atom in laser-plasma encircled by electric field, within the framework of perturbation theory formalism. Our numerical results show that for a weak external electric field and gargantuan length of Debye screening parameter, the system is strongly repulsive in contrast for strong external electric field and small length of Debye screening parameter, the system is very attractive. This work has potential application in the areas of atomic and molecular processes in external fields including interactions with strong fields and short pulses.
Spotting Virus from Satellites: Modeling the Circulation of West Nile Virus Through Graph Neural Networks
Creators: name: Bonicelli, Lorenzo
name: Porrello, Angelo
name: Vincenzi, Stefano
name: Ippoliti, Carla
name: Iapaolo, Federica
name: Conte, Annamaria
name: Calderara, Simone
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The occurrence of West Nile Virus (WNV) represents one of the most common mosquito-borne zoonosis viral infections. Its circulation is usually associated with climatic and environmental conditions suitable for vector proliferation and virus replication. On top of that, several statistical models have been developed to shape and forecast WNV circulation: in particular, the recent massive availability of Earth Observation (EO) data, coupled with the continuous advances in the field of Artificial Intelligence, offer valuable opportunities. In this paper, we seek to predict WNV circulation by feeding Deep Neural Networks (DNNs) with satellite images, which have been extensively shown to hold environmental and climatic features. Notably, while previous approaches analyze each geographical site independently, we propose a spatial-aware approach that considers also the characteristics of close sites. Specifically, we build upon Graph Neural Networks (GNN) to aggregate features from neighbouring places, and further extend these modules to consider multiple relations, such as the difference in temperature and soil moisture between two sites, as well as the geographical distance. Moreover, we inject time-related information directly into the model to take into account the seasonality of virus spread. We design an experimental setting that combines satellite images - from Landsat and Sentinel missions - with ground truth observations of WNV circulation in Italy. We show that our proposed Multi-Adjacency Graph Attention Network (MAGAT) consistently leads to higher performance when paired with an appropriate pre-training stage. Finally, we assess the importance of each component of MAGAT in our ablation studies.
description: 12 pages, 5 figures. Accepted at the IEEE Transactions On Geoscience And Remote Sensing
Do Androids Laugh at Electric Sheep? Humor "Understanding" Benchmarks from The New Yorker Caption Contest
Creators: name: Hessel, Jack
name: Marasović, Ana
name: Hwang, Jena D.
name: Lee, Lillian
name: Da, Jeff
name: Zellers, Rowan
name: Mankoff, Robert
name: Choi, Yejin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Large neural networks can now generate jokes, but do they really "understand" humor? We challenge AI models with three tasks derived from the New Yorker Cartoon Caption Contest: matching a joke to a cartoon, identifying a winning caption, and explaining why a winning caption is funny. These tasks encapsulate progressively more sophisticated aspects of "understanding" a cartoon; key elements are the complex, often surprising relationships between images and captions and the frequent inclusion of indirect and playful allusions to human experience and culture. We investigate both multimodal and language-only models: the former are challenged with the cartoon images directly, while the latter are given multifaceted descriptions of the visual scene to simulate human-level visual understanding. We find that both types of models struggle at all three tasks. For example, our best multimodal models fall 30 accuracy points behind human performance on the matching task, and, even when provided ground-truth visual scene descriptors, human-authored explanations are preferred head-to-head over the best machine-authored ones (few-shot GPT-4) in more than 2/3 of cases. We release models, code, leaderboard, and corpus, which includes newly-gathered annotations describing the image's locations/entities, what's unusual in the scene, and an explanation of the joke.
Transferring Implicit Knowledge of Non-Visual Object Properties Across Heterogeneous Robot Morphologies
Creators: name: Tatiya, Gyan
name: Francis, Jonathan
name: Sinapov, Jivko
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Humans leverage multiple sensor modalities when interacting with objects and discovering their intrinsic properties. Using the visual modality alone is insufficient for deriving intuition behind object properties (e.g., which of two boxes is heavier), making it essential to consider non-visual modalities as well, such as the tactile and auditory. Whereas robots may leverage various modalities to obtain object property understanding via learned exploratory interactions with objects (e.g., grasping, lifting, and shaking behaviors), challenges remain: the implicit knowledge acquired by one robot via object exploration cannot be directly leveraged by another robot with different morphology, because the sensor models, observed data distributions, and interaction capabilities are different across these different robot configurations. To avoid the costly process of learning interactive object perception tasks from scratch, we propose a multi-stage projection framework for each new robot for transferring implicit knowledge of object properties across heterogeneous robot morphologies. We evaluate our approach on the object-property recognition and object-identity recognition tasks, using a dataset containing two heterogeneous robots that perform 7,600 object interactions. Results indicate that knowledge can be transferred across robots, such that a newly-deployed robot can bootstrap its recognition models without exhaustively exploring all objects. We also propose a data augmentation technique and show that this technique improves the generalization of models. We release our code and datasets, here: https://github.com/gtatiya/Implicit-Knowledge-Transfer.
description: In proceedings of the IEEE International Conference on Robotics and Automation (ICRA), May 29 - June 2, 2023 , ExCeL London, UK
Measuring the Hubble Constant with cosmic chronometers: a machine learning approach
Creators: name: Bengaly, Carlos
name: Dantas, Maria Aldinez
name: Casarini, Luciano
name: Alcaniz, Jailson
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Local measurements of the Hubble constant ($H_0$) based on Cepheids e Type Ia supernova differ by $\approx 5 σ$ from the estimated value of $H_0$ from Planck CMB observations under $Λ$CDM assumptions. In order to better understand this $H_0$ tension, the comparison of different methods of analysis will be fundamental to interpret the data sets provided by the next generation of surveys. In this paper, we deploy machine learning algorithms to measure the $H_0$ through a regression analysis on synthetic data of the expansion rate assuming different values of redshift and different levels of uncertainty. We compare the performance of different regression algorithms as Extra-Trees, Artificial Neural Network, Gradient Boosting, Support Vector Machines, and we find that the Support Vector Machine exhibits the best performance in terms of bias-variance tradeoff in most cases, showing itself a competitive cross-check to non-supervised regression methods such as Gaussian Processes.
description: Typos corrected after proof-read. Matches published version in European Physical Journal C. Scripts available at https://github.com/astrobengaly/machine_learning_H0_v2
Diário Glicêmico
Creators: name: Alves, Thiago Aparecido
Publisher: name: Zenodo
Year: 2023

description: Diário Glicêmico desenvolvido para registro dos níveis glicêmicos em alguns horários do dia. Utilizado para acompanhamento e monitoramento dos pacientes diabéticos que possuem glicosímetro e insumos para mensuração da glicemia em domicílio.
A Detailed Study of Interpretability of Deep Neural Network based Top Taggers
Creators: name: Khot, Ayush
name: Neubauer, Mark S.
name: Roy, Avik
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Recent developments in the methods of explainable AI (XAI) allow researchers to explore the inner workings of deep neural networks (DNNs), revealing crucial information about input-output relationships and realizing how data connects with machine learning models. In this paper we explore interpretability of DNN models designed to identify jets coming from top quark decay in high energy proton-proton collisions at the Large Hadron Collider (LHC). We review a subset of existing top tagger models and explore different quantitative methods to identify which features play the most important roles in identifying the top jets. We also investigate how and why feature importance varies across different XAI metrics, how correlations among features impact their explainability, and how latent space representations encode information as well as correlate with physically meaningful quantities. Our studies uncover some major pitfalls of existing XAI methods and illustrate how they can be overcome to obtain consistent and meaningful interpretation of these models. We additionally illustrate the activity of hidden layers as Neural Activation Pattern (NAP) diagrams and demonstrate how they can be used to understand how DNNs relay information across the layers and how this understanding can help to make such models significantly simpler by allowing effective model reoptimization and hyperparameter tuning. These studies not only facilitate a methodological approach to interpreting models but also unveil new insights about what these models learn. Incorporating these observations into augmented model design, we propose the Particle Flow Interaction Network (PFIN) model and demonstrate how interpretability-inspired model augmentation can improve top tagging performance.
description: Repository: https://github.com/FAIR4HEP/xAI4toptagger. Some figure cosmetics have been changed. Accepted at Machine Learning: Science and Technology
Emotional labour in a tourism-based customer service context : an examination of the emotional labour, emotional dissonance and burnout sequence
Creators: name: Van Dijk., Pieter
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
A nonhomogeneous boundary value problem for the Kuramoto-Sivashinsky equation in a quarter plane
Creators: name: Li, Jing
name: Zhang, Bing-Yu
name: Zhang, Zhixiong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We study the initial boundary value problem for one-dimensional Kuramoto-Sivashinsky equation with nonhomogeneous boundary conditions. Through the analysis of the boundary integral operator, and applying the known results on the Cauchy problem, we obtain both the local well-posedness and the global well-posedness for the nonhomogeneous initial boundary value problem. It is shown that the Kuramoto-Sivashinsky equation is well-posed in Sobolev space $C([0,T]; H^s (R^+)) \bigcap L^2(0,T; H^{s+2}(R^+))$ for $s>-2$.
Surface plasmon enhancement of spontaneous emission in graphene waveguides
Creators: name: Cuevas, Mauro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: This work analyzes the spontaneous emission of a single emitter placed near the graphene waveguide formed by two parallel graphene monolayers, with an insulator spacer layer. In this case, the eigenmodes supported by the structure, such as surface plasmon and wave guided modes, provide decay channels for the electric dipole placed close to the waveguide. We calculated the contribution to the decay rate of symmetric and antisymmetric eigenmodes as a function of frequency and the orientation of the emitter. Our results show that the modification of the spontaneous emission due to excitation of guided modes is much lower than the corresponding decays through the excitation of symmetric and antisymmetric surface plasmons, for which, the spontaneous emission is dramatically enhanced. As a consequence of the high confinement of surface plasmons in the graphene waveguide, we found that the decay rate of the emitter with vertical orientation (with respect to graphene sheets) is twice the corresponding decay of the same emitter with parallel orientation in the whole frequency range where surface plasmon modes exist. Differently from metallo- dielectric structures, where structural parameters determine the range and magnitude of this emission, our work shows that, by dynamically tuning the chemical potential of graphene, the spectral region where the decay rate is enhanced can be chosen over a wide range.
description: 9 figures
Reconstructing directed and weighted topologies of phase-locked oscillator networks
Creators: name: Alderisio, Francesco
name: Fiore, Gianfranco
name: di Bernardo, Mario
Publisher: name: arXiv
Year: 2016
Subjects: subject: Dynamical Systems (math.DS)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The formalism of complex networks is extensively employed to describe the dynamics of interacting agents in several applications. The features of the connections among the nodes in a network are not always provided beforehand, hence the problem of appropriately inferring them often arises. Here, we present a method to reconstruct directed and weighted topologies (REDRAW) of networks of heterogeneous phase-locked nonlinear oscillators. We ultimately plan on using REDRAW to infer the interaction structure in human ensembles engaged in coordination tasks, and give insights into the overall behavior.
A hybridizable discontinuous Galerkin method for the coupled Navier-Stokes and Darcy problem
Creators: name: Cesmelioglu, Aycil
name: Rhebergen, Sander
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We present and analyze a strongly conservative hybridizable discontinuous Galerkin finite element method for the coupled incompressible Navier-Stokes and Darcy problem with Beavers-Joseph-Saffman interface condition. An a priori error analysis shows that the velocity error does not depend on the pressure, and that velocity and pressure converge with optimal rates. These results are confirmed by numerical examples.
TOPoS: III. An ultra iron-poor multiple CEMP system
Creators: name: Caffau, E.
name: Bonifacio, P.
name: Spite, M.
name: Spite, F.
name: Monaco, L.
name: Sbordone, L.
name: Francois, P.
name: Gallagher, A. J.
name: Plez, B.
name: Zaggia, S.
name: Ludwig, H. -G.
name: Cayrel, R.
name: Koch, A.
name: Steffen, M.
name: Salvadori, S.
name: Klessen, R.
name: Glover, S.
name: Christlieb, N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: One of the primary objectives of the TOPoS survey is to search for the most metal-poor stars. Our search has led to the discovery of one of the most iron-poor objects known, SDSS\,J092912.32+023817.0. This object is a multiple system, in which two components are clearly detected in the spectrum. We have analysed 16 high-resolution spectra obtained using the UVES spectrograph at the ESO 8.2m VLT telescope to measure radial velocities and determine the chemical composition of the system. Cross correlation of the spectra with a synthetic template yields a double-peaked cross-correlation function (CCF) for eight spectra, and in one case there is evidence for the presence of a third peak. Chemical analysis of the spectrum obtained by averaging all the spectra for which the CCF showed a single peak found that the iron abundance is [Fe/H]=-4.97. The system is also carbon enhanced with [C/Fe]=+3.91 (A(C)=7.44). From the permitted oxygen triplet we determined an upper limit for oxygen of [O/Fe]1.3. We are also able to provide more stringent upper limits on the Sr and Ba abundances ([Sr/Fe]
description: Accepted for publication in A&A Letter
Dark Matter prospects with COSI: ALPs, PBHs and sub-GeV Dark Matter
Creators: name: Caputo, Andrea
name: Negro, Michela
name: Regis, Marco
name: Taoso, Marco
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study the prospects in the search of dark matter offered by the newly selected NASA MeV mission COSI (Compton Spectrometer and Imager). This instrument is designed and optimized to detect spectral lines, and we show it offers an exquisite possibility to detect dark matter directly decaying or annihilating into monochromatic gamma-rays. This is the case, for example, for axion-like particles (ALPs) which undergo decay into two photons. Furthermore, we show that COSI can lead to important progress in the quest for primordial black holes (PBHs) dark matter, through measurements of the 511 keV line from the positrons produced via Hawking evaporation. We also outline opportunities for the search of continuum signals, such as those expected from sub-GeV dark matter annihilation/decay into leptons and PBH evaporation into photons. We find that also in this case COSI can lead to improvements of current bounds.
description: Matches the published version
International trade and the demand for European labour
Creators: name: Tsafack., Esther
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.