cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Large deviations of lattice Hamiltonian dynamics coupled to stochastic thermostats
Creators: name: Bodineau, T.
name: Lefevere, R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We discuss the Donsker-Varadhan theory of large deviations in the framework of Hamiltonian systems thermostated by a Gaussian stochastic coupling. We derive a general formula for the Donsker-Varadhan large deviation functional for dynamics which satisfy natural properties under time reversal. Next, we discuss the characterization of the stationary state as the solution of a variational principle and its relation to the minimum entropy production principle. Finally, we compute the large deviation functional of the current in the case of a harmonic chain thermostated by a Gaussian stochastic coupling.
description: Revised version, published in Journal of Statistical Physics
The Lorentz Transformation for Photons in Dispersive Media and in Gravitational Fields
Creators: name: Buenker, Robert J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: It is pointed out that the traditional explanation for the observation of a non-zero energy h nu for light in free space does not apply for the analogous situation in dispersive media. Because the speed of light u is no longer equal to c in this case, the key quantity, gamma = (1-u2/c2)-0.5, is finite as a result. Since the rest energy of photons is believed to always be equal to zero, multiplying it with gamma in analogy to the usual procedure employed in the special theory of relativity (STR) does not produce a nonzero result for photons in dispersive media. The experimental evidence of the Fizeau light-drag and Cerenkov radiation phenomena indicate that the Lorentz transformation in free space is nonetheless valid for light in dispersive media. Instead, the energy and momentum of photons in transparent media can be obtained from observations of the frequency, wavelength and index of refraction of the light. A modification of the Lorentz transformation in which the observed speed of light does appear explicitly is required, however, in order to accurately predict the results of measurements made when the observer is at a different gravitational potential than the object.
Magic-angle Bilayer Phononic Graphene
Creators: name: Deng, Yuanchen
name: Oudich, Mourad
name: Gerard, Nikhil JRK
name: Ji, Jun
name: Lu, Minghui
name: Jing, Yun
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Thanks to the recent discovery on the magic-angle bilayer graphene, twistronics is quickly becom11 ing a burgeoning field in condensed matter physics. This letter expands the realm of twistronics to acoustics by introducing twisted bilayer phononic graphene, which remarkably also harbors the magic angle, evidenced by the associated ultra-flat bands. Beyond mimicking quantum mechanical behaviors of twisted bilayer graphene, we show that their acoustic counterpart offers a considerably more straightforward and robust way to alter the interlayer hopping strength, enabling us to unlock magic angles (> 3 degrees) inaccessible in classical twisted bilayer graphene. This study, not only establishes the acoustical analog of twisted (magic-angle) bilayer graphene, providing a testbed more easily accessible to probe the interaction and misalignment between stacked 2D materials, but also points out the direction to a new phononic crystal design paradigm that could benefit applications such as enhanced acoustic emission and sensing.
Supersymmetry Breaking by Constant Boundary Superpotentials in Warped Space
Creators: name: Maru, Nobuhito
name: Sakai, Norisuke
name: Uekusa, Nobuhiro
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Supersymmetry breaking by constant (field independent) superpotentials localized at boundaries is studied in a supersymmetric warped space model. We calculate the Kaluza-Klein mass spectrum of the hypermultiplet. We take into account of the radion and the compensator supermultiplets, as well as the bulk mass $c$ for the hypermultiplet. The mass splitting is similar to that of the Scherk-Schwarz supersymmetry breaking (in flat space) for large $|c|$, and has an interesting dependence on the bulk mass parameter $c$. We show that the radius is stabilized by the presence of the constant boundary superpotentials.
description: 24 pages, 9 figures; Section 5 is replaced by the new analysis of the radius stabilization, small modifications made
N-dimensional Vaidya metric with cosmological constant in double-null coordinates
Creators: name: Saa, Alberto
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A recently proposed approach to the construction of the Vaidya metric in double-null coordinates for generic mass functions is extended to the $n$-dimensional $(n>2)$ case and to allow the inclusion of a cosmological constant. The approach is based on a qualitative study of the null-geodesics, allowing the description of light-cones and revealing many features of the underlying causal structure. Possible applications are illustrated by explicit examples. Some new exact solutions are also presented and discussed. The results presented here can simplify considerably the study of spherically symmetric gravitational collapse and mass accretion in arbitrary dimensions.
description: 11 pages, 5 figs. Final version to appear in PRD
SEPARATION OF FINE LIQUID DROPLETS FROM HIGH SPEED AIR UTILIZING THE ELECTROHYDRODYNAMICS TECHNIQUE
Creators: name: Yang, Ning
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Mechanical engineering
subject: FOS: Mechanical engineering
subject: Collection Efficiency
subject: Electrostatic Separator

description: With constant process intensification in recent years, the separation of fine micron and submicron size liquid droplets from gaseous flow mediums has become an important subject for the process and aerospace industries. While conventional technologies are not effective in this droplet size range, electrostatic separation demonstrated remarkable effectiveness and reliability while lowering maintenance and operation cost. However, it is commonly used for low droplet concentration in relatively low velocity gas flow. This current experimental study is focused on electrostatic separation of high concentration of fine electrically conductive droplets from high velocity gas flow. Different separators including wire-to-plate, wire-to-cylinder, single stage, and multi-stage separators were designed, built and tested at gas velocities up to 15 m/sec and droplet concentration up to 22,000 ppm. The results demonstrated that two-stage plate, as well as tubular separators provides maximum separation efficiency at minimum power consumption. However, the tubular separator is easier to package in the required space envelope and 1-inch diameter tubes are more efficient at high velocity and droplet concentrations.
Nuclear Track Detectors for Environmental Studies and Radiation Monitoring
Creators: name: Manzoor, S.
name: Balestra, S.
name: Cozzi, M.
name: Errico, M.
name: Giacomelli, G.
name: Giorgini, M.
name: Kumar, A.
name: Margiotta, A.
name: Medinaceli, E.
name: Patrizii, L.
name: Popa, V.
name: Qureshi, I. E.
name: Togo, V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Several improvements were made for Nuclear Track Detectors (NTDs) used for environmental studies and for particle searches. A new method was used to determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the simultaneous measurement of the diameter and of the height of etch-pit cones caused by relativistic heavy ions (158 A GeV Pb(82+) and In(49+) ions) and their fragments. The use of alcohol in the etching solution improves the surface quality of NTDs and it raises their thresholds. The detectors were used for the determination of nuclear fragmentation cross sections of Iron and Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for the determination of doses in hadron therapy and for doses received by astronauts. The detectors were also used in the search of massive particles in the cosmic radiation, for the determination of the mass spectrum of cosmic rays and for the evaluation of Po(210) alpha decay and of natural radon concentrations.
description: 7 pages, 5 EPS figures. Presented at the 10th Topical Seminar on Innovative Particle and Radiation Detectors, 1-5 October 2006, Siena, Italy
PRIORITIZING AND SCHEDULING INTERRELATED ROAD PROJECTS USING METAHEURISTIC ALGORITHMS
Creators: name: Shayanfar, Elham
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Civil engineering
subject: FOS: Civil engineering
subject: Transportation
subject: infrastructure improvement
subject: metaheuristics
subject: planning
subject: prioritizing
subject: project evaluation

description: Projects are considered interrelated when their benefits or costs depend on which other projects are implemented. Selection and scheduling of interrelated projects is a challenging optimization problem which has applications in various fields including economics, operations research, business, management and transportation. The goal is to determine which projects should be selected and when they should be funded in order to minimize the total system cost over a planning horizon subject to a budget constraint. The budget is supplied by both external and internal sources from fuel tax revenues. This study then applies three meta-heuristic algorithms including a Genetic Algorithm (GA), Simulated Annealing (SA) and, Tabu Search (TS) in seeking efficient and consistent solutions to the selection and scheduling problem. These approaches are applied to a special case of link capacity expansion projects to showcase their functionality and compare their performance in terms of solution quality, computation time and consistency.
Gravitational Axiverse Spectroscopy: Seeing the Forest for the Axions
Creators: name: Dimastrogiovanni, Ema
name: Fasiello, Matteo
name: Leedom, Jacob Michael
name: Putti, Margherita
name: Westphal, Alexander
Publisher: name: Deutsches Elektronen-Synchrotron, DESY, Hamburg
Year: 2023
Subjects: string, compactification
axion, coupling
gauge field theory, abelian
spectator, model
axion, string
energy, injection
gauge field theory, quantization
gravitational radiation, stochastic
spectrum, tensor
inflation, model
spectral
dimensional reduction
differential forms
orientifold
D-brane
slow-roll approximation
cosmic background radiation
field strength
membrane model
ultraviolet
Chern-Simons term
background
landscape

description: We consider inflationary models with multiple spectator axions that couple to dark Abelian gauge sectors. We demonstrate two distinctive phenomena that make this class of models attractive -- first, we show that separation of the gravitational wave peaks can occur, depending on the axion initial conditions and mass. This leads to a distinctive gravitational wave (GW) forest, whose observation would be a signal that multiple axions exist within the universe. We relate these models to the recent PTA observations. Second, the gravitational wave peak produced by axions coupled to dark Abelian sectors can coherently sum, leading to an enhanced signal. This also serves as a mechanism to lower the value of the Chern-Simons (CS) coupling required to produce a signal visible by PTA. Finally, we elaborate on possible ultraviolet origins of the spectator models utilizing string axions descending from p-form gauge field coupled to D-branes. String theory compactifications generically produce an `axiverse', that is, many of these string axions. Their coupling to D-branes in turn generates CS couplings to dark gauge fields which can be enhanced via multiple brane wrappings and/or quantized gauge field strengths (fluxes). If these string axions then undergo slow-roll during inflation, they produce GW signals with peaked frequency distribution which are potentially detectable. We discuss the non-trivial requirements for such U(1) gauge field coupled string axions to occur in type IIB string compactifications on Calabi-Yau orientifolds with fluxes, and provide a rudimentary classification of some options.
Noise-dependent stability of the synchronized state in a coupled system of active rotators
Creators: name: Brandt, Sebastian F.
name: Pelster, Axel
name: Wessel, Ralf
Publisher: name: arXiv
Year: 2008
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We consider a Kuramoto model for the dynamics of an excitable system consisting of two coupled active rotators. Depending on both the coupling strength and the noise, the two rotators can be in a synchronized or desynchronized state. The synchronized state of the system is most stable for intermediate noise intensity in the sense that the coupling strength required to desynchronize the system is maximal at this noise level. We evaluate the phase boundary between synchronized and desynchronized states through numerical and analytical calculations.
description: Author Information under http://www.theo-phys.uni-essen.de/tp/ags/pelster_dir/
A survey on practical adversarial examples for malware classifiers
Creators: name: Park, Daniel
name: Yener, Bülent
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cryptography and Security (cs.CR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Machine learning based solutions have been very helpful in solving problems that deal with immense amounts of data, such as malware detection and classification. However, deep neural networks have been found to be vulnerable to adversarial examples, or inputs that have been purposefully perturbed to result in an incorrect label. Researchers have shown that this vulnerability can be exploited to create evasive malware samples. However, many proposed attacks do not generate an executable and instead generate a feature vector. To fully understand the impact of adversarial examples on malware detection, we review practical attacks against malware classifiers that generate executable adversarial malware examples. We also discuss current challenges in this area of research, as well as suggestions for improvement and future research directions.
description: preprint. to appear in the Reversing and Offensive-oriented Trends Symposium(ROOTS) 2020
Frank Lloyd Wright : before and after 1905 : Exploration of formal design analysis in the interactive multimedia environment
Creators: name: Oki, Yoriko
Publisher: name: University of British Columbia
Year: 2009

description: The purpose of this thesis is to integrate computer use in architectural design analysis and to verify the computer's usefulness in this category of research. The vehicle of this project is the study of Frank Lloyd Wright's Prairie Houses: particularly their design differences after 1905, when Wright made his first trip to Japan. The research corpus consists of the Prairie Houses designed between 1901 and 1910. The original drawings were scanned into the computer and organized as a database, "The Reference Library." With the CAD ystem, the drawings of ten selected houses were traced and studied. The difference recognized in these examples was examined against other houses using "The Reference Library." 0he CAD system was also utilized to acquire measurements in the design. This data was organized in a spreadsheet file. In addition, 3-D modeling and digital animation for two houses were undertaken. As a result of the study described above, it was found that changes in Wright's design occurred in many aspects. A greater sense of connection was observed within the house. The connection between the indoor and outdoor space was increased both visually and physically. The exterior expression was transformed from stable to dynamic. These design changes provide greater spatial fluidity, than his earlier designs afforded, and have something in common with the characteristics of traditional Japanese architecture. As the final stage of this thesis, its publication was undertaken in an interactive multimedia environment. Various aspects of this new publication format were experimented with, while still retaining some conventional publication methods. A characteristic of the computer publication is the flexibility in arranging and linking individual components. In addition, Video clips and sound clips allowed dynamic presentation. Thus, multimedia publication changes the publication tradition for all — writers, publishers and readers. Throughout this thesis, the computer showed its usefulness and potential in architectural design formal analysis. In many cases, the computer increased the efficiency of research and offered me new choices apart from conventional research methods. Each aspect of computer use examined in this thesis was found very useful and can be utilized individually in future research.
Analytic Approach for Controlling Quantum States in Complex Systems
Creators: name: Takami, Toshiya
name: Fujisaki, Hiroshi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Chemical Physics (physics.chem-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We examine random matrix systems driven by an external field in view of optimal control theory (OCT). By numerically solving OCT equations, we can show that there exists a smooth transition between two states called "moving bases" which are dynamically related to initial and final states. In our previous work [J. Phys. Soc. Jpn. 73 (2004) 3215-3216; Adv. Chem. Phys. 130A (2005) 435-458], they were assumed to be orthogonal, but in this paper, we introduce orthogonal moving bases. We can construct a Rabi-oscillation like representation of a wavpacket using such moving bases, and derive an analytic optimal field as a solution of the OCT equations. We also numerically show that the newly obtained optimal field outperforms the previous one.
description: 12 pages, 8 figures, formatted by REVTeX-4, submitted to Phys. Rev. E
title: Triangulation Guided High Clearance Collision-Free Paths
Creators: name: Maharjan, Sandeep
Publisher: name: University of Nevada, Las Vegas
publisherIdentifier: https://ror.org/0406gha72
publisherIdentifierScheme: ROR
Year: 2024

description: Algorithms dealing with the construction of high clearance collision-free paths in the presence of polygonal obstacles is an important problem in robotics and transportation engineering. Method of extracting collision-free paths guided by triangulation of free space is examined. Two algorithms for improving the standard triangulation guided algorithms are presented. The time complexities of the presented algorithms are analysed. Finally, further applications of the proposed techniques are discussed.
On quantum phase crossovers in finite systems
Creators: name: Dunning, Clare
name: Hibberd, Katrina E.
name: Links, Jon
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this work we define a formal notion of a quantum phase crossover for certain Bethe ansatz solvable models. The approach we adopt exploits an exact mapping of the spectrum of a many-body integrable system, which admits an exact Bethe ansatz solution, into the quasi-exactly solvable spectrum of a one-body Schrödinger operator. Bifurcations of the minima for the potential of the Schrödinger operator determine the crossover couplings. By considering the behaviour of particular ground-state correlation functions, these may be identified as quantum phase crossovers in the many-body integrable system with finite particle number. In this approach the existence of the quantum phase crossover is not dependent on the existence of a thermodynamic limit, rendering applications to finite systems feasible. We study two examples of bosonic Hamiltonians which admit second-order crossovers.
description: 11 pages, 2 figures. Final version accepted for publication
Trans-Alfvenic Magnetohydrodynamic Turbulence in the Vicinity of Supernova Remnant Cassiopeia-A Shocks
Creators: name: Vishwakarma, Pavan Kumar
name: Kumar, Jais
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Statistics of the magnetic field disturbances in the supernova remnants (SNRs) can be accessed using the second-order correlation function of the synchrotron intensities. Here we measure the magnetic energy spectra in supernova remnant Cassiopeia-A by two-point correlation of the synchrotron intensities, using a recently developed unbiased method. The measured magnetic energy spectra in the vicinity of supernova remnant shocks are found to be 2/3 power law over the decade of range scales, showing the developed trans-Alfvenic magnetohydrodynamic turbulence. Our results are globally consistent with the theoretical prediction of trans-Alfvenic Mach number in developed magneto-hydrodynamic turbulence and can be explained by the amplification of the magnetic field in the vicinity of SNR shocks. The magnetic energy spectra predict SNR Cassiopeia-A having an additional subshock in the radio frequency observation along with forward and reverse shocks, with a radial window of the amplified magnetic field of ~ 0.115pc near the shocks
description: 6 pages, 9 figures, published in MNRAS
title: Unraveling the Relationship between Social Vulnerability Index and COVID-19 Prevalence in Southern Nevada
Creators: name: Lopez, Andrea
Publisher: name: University of Nevada, Las Vegas
publisherIdentifier: https://ror.org/0406gha72
publisherIdentifierScheme: ROR
Year: 2024

description: The COVID-19 pandemic was a catastrophic global event that exacerbated public health issues and disparities, especially in socially vulnerable communities. Thus, this study examines areas classified by the CDC's Social Vulnerability Index (SVI) metric, which assesses vulnerable communities experiencing adverse events through sixteen social determinants that impact health. The purpose of this study will be to determine if (1) COVID-19 testing rates and/or COVID-19 vaccination rates mediate SVI and COVID-19 prevalence rates and (2) if COVID-19 testing rate and COVID-19 vaccination rates serially mediate SVI and COVID-19 prevalence rates. In order to achieve this, census tracts within Southern Nevada will be analyzed from January 2020 to June 2022. Mediation analyses with linear regression were employed to examine complex relationships among SVI, COVID-19 testing, vaccination, and prevalence rates. The 95% confidence intervals of indirect effects were particularly computed using a bootstrap technique to determine whether a mediator was statistically significant. Results display that the COVID-19 testing rate (indirect effect = -3.98; 95% CI = -7.43, -0.11), COVID-19 full-vaccination rate (indirect effect = -1.88; 95% CI = -7.54, -0.95), and COVID-19 follow-up vaccination rate (indirect effect = -11.52; 95% CI = -15.97, -6.49) negatively mediates the relationship between SVI and COVID-19 prevalence rate. Our serial mediation analysis showed that an increase in SVI was significantly inversely associated with a significant total indirect effect of -0.02 (95% CI = -0.03, -0.002) from the sequential pathway from COVID-19 testing rate, COVID-19 full vaccination rate, and COVID-19 follow-up vaccination rate as serial mediators. These findings further highlight the impact of infectious outbreaks from access to vaccination and testing resources in socially vulnerable communities, underscoring the need for public health professionals to develop sustainable interventions.
Theory of the Franck-Condon blockade regime
Creators: name: Koch, Jens
name: von Oppen, Felix
name: Andreev, A. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Strong coupling of electronic and vibrational degrees of freedom entails a low-bias suppression of the current through single-molecule devices, termed Franck-Condon blockade. In the limit of slow vibrational relaxation, transport in the Franck-Condon-blockade regime proceeds via avalanches of large numbers of electrons, which are interrupted by long waiting times without electron transfer. The avalanches consist of smaller avalanches, leading to a self-similar hierarchy which terminates once the number of transferred electrons per avalanche becomes of the order of unity. Experimental signatures of self-similar avalanche transport are strongly enhanced current (shot) noise, as expressed by giant Fano factors, and a power-law noise spectrum. We develop a theory of the Franck-Condon-blockade regime with particular emphasis on effects of electron cotunneling through highly excited vibrational states. As opposed to the exponential suppression of sequential tunneling rates for low-lying vibrational states, cotunneling rates suffer only a power-law suppression. This leads to a regime where cotunneling dominates the current for any gate voltage. Including cotunneling within a rate-equation approach to transport, we find that both the Franck-Condon blockade and self-similar avalanche transport remain intact in this regime. We predict that cotunneling leads to absorption-induced vibrational sidebands in the Coulomb-blockaded regime as well as intrinsic telegraph noise near the charge degeneracy point.
description: 20 pages, 10 figures; minor changes, version published in Phys. Rev. B
Brief lectures on duality, integrability and deformations
Creators: name: Klimcik, Ctirad
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We provide a pedagogical introduction to some aspects of integrability, dualities and deformations of physical systems in 0+1 and in 1+1 dimensions. In particular, we concentrate on the T-duality of point particles and strings as well as on the Ruijsenaars duality of finite many-body integrable models, we review the concept of the integrability and, in particular, of the Lax integrability and we analyze the basic examples of the Yang-Baxter deformations of non-linear sigma-models. The central mathematical structure which we describe in detail is the E-model which is the dynamical system exhibiting all those three phenomena simultaneously. The last part of the paper contains original results, in particular a formulation of sufficient conditions for strong integrability of non-degenerate E-models.
description: 43 pages, the origin (URL) of the pictures is specified
Networks of Empire: The Role of Infrastructure in Wari State Expansion in Arequipa, Peru (AD 600-1000)
Creators: name: Reid, David Aaron
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: In this dissertation I investigate the role of road infrastructure (i.e. the built networks of communication, travel, and commerce) in the expansion of one of South America’s first empires: the Wari of the Andean highlands, whose material culture and customs spread across much of Peru during the Middle Horizon (A.D. 600-1000). Despite considerable research of Wari administrative centers in provincial settings, the mechanisms underlying Wari expansionism remain poorly problematized. Here I take a multi-scalar approach to investigate a network of Middle Horizon roads and associated waystations established by both the Wari state and local communities along Wari’s southern frontier in the department of Arequipa, Peru. This study integrates multi-disciplinary methodologies that include GIS modeling of mobility routes, satellite-imagery remote sensing, UAV (drone) technology, regional analysis, and traditional archaeological survey and excavation. As roads embody the complex social relationships that led to their construction, use, and maintenance over time, this single road network provides evidence of state versus local political economic strategies, the emergence of new religious institutions, and ideological shifts that often accompany the unintended consequences of empire.
title: Python in der sozialwissenschaftlichen Methodenlehre : Motivation und Erfahrungsbericht eines Lehrprojekts
Creators: name: Elis, Jonas
name: Eicheler, Jakob Jonathan
name: Plenter, Johanna
name: Vierus, Paul
Publisher: name: DuEPublico
Year: 2025
Subjects: classificationCode: 5.6
subject: FOS: Political science

description: “SPSS, STATA, R und jetzt auch noch Python?” – dieser oder zumindest ein ähnlicher Gedanke mag vielen Leser*innen beim Anblick des Titels dieses Blogposts womöglich durch den Kopf gegangen sein. In diesem Beitrag möchten wir darlegen, warum wir Python für eine sinnvolle Ergänzung der politikwissenschaftlichen Methodenlehre halten und gleichzeitig von unseren Erfahrungen in der Durchführung berichten.
Three-Parton Contributions to B --> M_1 M_2 Annihilation at Leading Order
Creators: name: Arnesen, Christian M.
name: Rothstein, Ira Z.
name: Stewart, Iain W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We compute annihilation amplitudes for charmless B decays that are proportional to the three-parton twist-3 light meson distribution amplitude phi_{3M}(x1,x2) with an active gluon. Due to an enhancement from a quark propagator at the scale p^2 ~ mbΛ_QCD these terms occur at the same parametric order in alpha_s(mb) and 1/mb as the known leading order annihilation involving fB and twist-2 meson distributions. With our calculation the leading order annihilation amplitude is now complete. At lowest order in alpha_s the amplitudes are real and only O_{5-8} contribute. Using simple models we find that the three-parton and two-parton terms are of comparable size.
description: 13 pages, 2 figures. Sign convention modified for consistency with hep-ph/0401188
Where are all the gravastars? Limits upon the gravastar model from accreting black holes
Creators: name: Broderick, Avery E.
name: Narayan, Ramesh
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The gravastar model, which postulates a strongly correlated thin shell of anisotropic matter surrounding a region of anti-de Sitter space, has been proposed as an alternative to black holes. We discuss constraints that present-day observations of well-known black hole candidates place on this model. We focus upon two black hole candidates known to have extraordinarily low luminosities: the supermassive black hole in the Galactic Center, Sagittarius A*, and the stellar-mass black hole, XTE J1118+480. We find that the length scale for modifications of the type discussed in Chapline et al. (2003) must be sub-Planckian.
description: 11 pages, 4 figures
Dyonic Objects and Tensor Network Representation
Creators: name: Belhaj, A.
name: Maadi, Y. El
name: Ennadifi, S. E.
name: Hassouni, Y.
name: Sedra, M. B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Motivated by particle phyiscs results, we investigate certain dyonic solutions in arbitrary dimensions. Concretely, we study the stringy constructions of such objects from concrete compactifications. Then we elaborate their tensor network realizations using multistate particle formalism.
description: 14 pages, 2 figures, 2 tables. To appear in MPLA (2020)
RAILCAR FLOW MANAGEMENT IN INDUSTRIAL TRANSPORT SYSTEMS (УПРАВЛЕНИЕ ВАГОНОПОТОКАМИ В ПРОМЫШЛЕННЫХ ТРАНСПОРТНЫХ СИСТЕМАХ)
Creators: name: Osintsev, Nikita
name: Rakhmangulov, Aleksandr
Publisher: name: figshare
Year: 2021
Subjects: subject: 99999 Engineering not elsewhere classified
subject: FOS: Other engineering and technologies

description: The results of the analysis of freight and wagon traffic on the industrial transport systems. Provides a system and methods of control in the industrial and wagon transport systems based on the use of logistics principles.В статье представлены результаты анализа грузо- и вагонопотоков в промышленных транспортных системах металлургических предприятий. Предложена система и методы управления вагонопотоками в промышленных транспортных системах, основанные на использовании логистических принципов.
title: The Effect of Transcranial Direct Current Stimulation of the Dorsolateral Prefrontal Cortex on Muscle Fatigue Resistance
Creators: name: Liddell, Taylie
Publisher: name: University of Nevada, Las Vegas
publisherIdentifier: https://ror.org/0406gha72
publisherIdentifierScheme: ROR
Year: 2024

description: Transcranial direct current stimulation (tDCS) delivered to the dorsolateral prefrontal cortex (DLPFC) can increase endurance time in lower body cycling tasks. The purpose was to examine the effect of DLPFC-tDCS on the time to task failure (TTF) of a fatiguing contraction performed by hand muscles. The study used a double-blind, randomized, SHAM-controlled, crossover design. Participants completed two experimental sessions on separate days with a washout between sessions. All facets of the experiments were identical except the stimulation condition (DLPFC-tDCS or SHAM) that was given concurrent with the fatiguing contraction. The fatiguing contraction involved gripping a manipulandum with the index finger and thumb using a precision grip and matching an isometric target equal to 15% of the maximum voluntary contraction (MVC) for as long as possible until task failure. The main findings were that TTF and fatigue index did not differ between the DLPFC-tDCS and SHAM conditions. Furthermore, there was no significant differences during the fatiguing contractions in the rates of increase of electromyographic (EMG), force error, or standard deviation (SD) of force between the DLPFC-tDCS and SHAM conditions. Overall, the results indicate that application of DLPFC-tDCS does not reduce the rate of muscle fatigue development in the current task conditions.
Understanding the Role of Individual Units in a Deep Neural Network
Creators: name: Bau, David
name: Zhu, Jun-Yan
name: Strobelt, Hendrik
name: Lapedriza, Agata
name: Zhou, Bolei
name: Torralba, Antonio
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences
subject: I.4; I.2
subject: 68T07

description: Deep neural networks excel at finding hierarchical representations that solve complex tasks over large data sets. How can we humans understand these learned representations? In this work, we present network dissection, an analytic framework to systematically identify the semantics of individual hidden units within image classification and image generation networks. First, we analyze a convolutional neural network (CNN) trained on scene classification and discover units that match a diverse set of object concepts. We find evidence that the network has learned many object classes that play crucial roles in classifying scene classes. Second, we use a similar analytic method to analyze a generative adversarial network (GAN) model trained to generate scenes. By analyzing changes made when small sets of units are activated or deactivated, we find that objects can be added and removed from the output scenes while adapting to the context. Finally, we apply our analytic framework to understanding adversarial attacks and to semantic image editing.
description: Proceedings of the National Academy of Sciences 2020. Code at https://github.com/davidbau/dissect/ and website at https://dissect.csail.mit.edu/
Faithful derivation of symmetry indicators: A case study for topological superconductors with time-reversal and inversion symmetries
Creators: name: Huang, Sheng-Jie
name: Hsu, Yi-Ting
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Topological crystalline superconductors have attracted rapidly rising attention due to the possibility of higher-order phases, which support Majorana modes on boundaries in $d-2$ or lower dimensions. However, although the classification and bulk topological invariants in such systems have been well studied, it is generally difficult to faithfully predict the boundary Majoranas from the band-structure information due to the lack of well-established bulk-boundary correspondence. Here we propose a protocol for deriving symmetry indicators that depend on a minimal set of necessary symmetry data of the bulk bands and can diagnose boundary features. Specifically, to obtain indicators manifesting clear bulk-boundary correspondence, we combine the topological crystal classification scheme in the real space and a twisted equivariant K group analysis in the momentum space. The key step is to disentangle the generally mixed strong and weak indicators through a systematic basis-matching procedure between our real-space and momentum-space approaches. We demonstrate our protocol using an example of two-dimensional time-reversal odd-parity superconductors, where the inversion symmetry is known to protect a higher-order phase with corner Majoranas. Symmetry indicators derived from our protocol can be readily applied to ab initio database and could fuel material predictions for strong and weak topological crystalline superconductors with various boundary features.
description: 27 pages, 9 figures, 2 tables
Extremal orders of compositions of certain arithmetical functions
Creators: name: Sándor, József
name: Tóth, László
Publisher: name: arXiv
Year: 2008
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11A25, 11N37

description: We study the exact extremal orders of compositions $f(g(n))$ of certain arithmetical functions, including the functions $σ(n)$, $ϕ(n)$, $σ^*(n)$ and $ϕ^*(n)$, representing the sum of divisors of $n$, Euler's function and their unitary analogues, respectively. Our results complete, generalize and refine known results.
description: improved and corrected final version
ALMA and IRIS Observations of the Solar Chromosphere II: Structure and Dynamics of Chromospheric Plage
Creators: name: Chintzoglou, Georgios
name: De Pontieu, Bart
name: Martínez-Sykora, Juan
name: Hansteen, Viggo
name: Rodríguez, Jaime de la Cruz
name: Szydlarski, Mikolaj
name: Jafarzadeh, Shahin
name: Wedemeyer, Sven
name: Bastian, Timothy S.
name: Dalda, Alberto Sainz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We propose and employ a novel empirical method for determining chromospheric plage regions, which seems to better isolate plage from its surrounding regions compared to other methods commonly used. We caution that isolating plage from its immediate surroundings must be done with care in order to successfully mitigate statistical biases that, for instance, can impact quantitative comparisons between different chromospheric observables. Using this methodology, our analysis suggests that 1.25 mm wavelength free-free emission in plage regions observed with ALMA/Band6 may not form in the low chromosphere as previously thought, but rather in the upper chromospheric parts of dynamic plage features (such as spicules and other bright structures), i.e., near geometric heights of transition region temperatures. We investigate the high degree of similarity between chromospheric plage features observed in ALMA/Band6 (at 1.25 mm wavelength) and IRIS/Si IV at 1393Å. We also show that IRIS/Mg II h and k is not as well correlated with ALMA/Band6 as was previously thought, and we discuss the discrepancies with previous works. Lastly, we report indications for chromospheric heating due to propagating shocks supported by the ALMA/Band6 observations.
description: 35 pages, 8 figures, 3 online movies and 1 Appendix. Accepted for publication in the Astrophysical Journal. This preprint is a companion paper to the replacement of arXiv:2005.12717
Magnetic Coupling of a Rotating Black Hole with Advection-Dominated Accretion Flows
Creators: name: Ye, Yong-Chun
name: Wang, Ding-Xiong
name: Ma, Ren-Yi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A model of magnetic coupling (MC) of a rotating black hole (BH) with advection- dominated accretion flow (MCADAF) is proposed. It turns out that MCADAF providers a natural explanation for the transition radius between ADAF and SSD, and could be used to interpret the highest luminosity of GX 339-4 in hard-state. A very steep emissivity index can be produced in the innermost part of the MCADAF,which is consistent with the recent XMM-Newton observations of the nearby bright Seyfert 1 galaxy MCG-6-30-15 and with two X-ray binaries (XRBs): XTE J1655-500 and GX 339-4. In addition, we estimate the BH spins in Seyfert 1 galaxy MCG-6-30-15 and in the two XRBs based on this model.
description: 18 pages, 9 figures,acceptted by New Astronomy
Characterization and enumeration of the resin acid-degrading bacterial population of a sequencing batch reactor: an emphasis on the isopimaric acid-degrading bacteria
Creators: name: Wilson, Ann Elise-Jordan
Publisher: name: University of British Columbia
Year: 2009

description: Resin acids are naturally occurring compounds produced by conifers and released by pulp and paper mills. These compounds are problematic to papermaking processes and are highly toxic to aquatic organisms. Since basic microbial research on biodegradation of resin acids is limited, it was of interest to investigate the resin acid-degrading community of an established sequencing batch reactor operated at temperatures between 20° and 50°C; to determine if operating temperature changes affected the species present. Specificities for resin acids and other substrates, temperature ranges for and induction of resin acid degradation were characterized for several isolates. Five resin acid-degrading bacterial strains were isolated from the sequencing batch reactor at either 20° or 40°C. AbA-1 grew on the abietanes, dehydroabietic and abietic acids. IpA-1, IpA-2, IpA-13, and AbA-5 grew on the pimaranes, isopimaric and pimaric acids, and the above abietanes. These latter four strains are the first reported isolates which grow on the pimaranes as a sole organic carbon and energy sources. Carbon mass balance determinations for IpA-1, IpA-2 and IpA-13 could not conclusively prove that isopimaric acid was completely mineralized because one-third of the isopimaric acid carbon remained as dissolved organic carbon; however, partial mineralization was shown. IpA-1 did not produce a biosurfactant during growth on isopimaric acid. Induction studies confirmed removal of resin acids by isopimaric acid degraders requires induction by growth on IpA. When the five strains were compared biochemically, the results suggested that increasing the temperature of the sequencing batch reactor from 20° to 40°C changed the resin aciddegrading bacterial community, from one with at least two gram-negative populations, abietane and pimarane-degrading ones, to a less diverse one with a gram-positive population having the ability to remove both abietanes and pimaranes. Most probable number determinations showed increasing the reactor's temperature above 40°C decreased the culturable isopimaric, dehydroabietic, and abietic acid-degrading populations to 103 per 100 ml. The remaining populations above 40°C required additional energy sources to remove resin acids. The resin acid-degrading community was resilient to rapid changes in resin acid concentration up to 3000 pM and pH shifts to 6 or 8.
Quantum String Seal Is Insecure
Creators: name: Chau, H. F.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A quantum string seal encodes the value of a (bit) string as a quantum state in such a way that everyone can extract a non-negligible amount of available information on the string by a suitable measurement. Moreover, such measurement must disturb the quantum state and is likely to be detected by an authorized verifier. In this way, the intactness of the encoded quantum state plays the role of a wax seal in the digital world. Here I analyze the security of quantum string seal by studying the information disturbance tradeoff of a measurement. This information disturbance tradeoff analysis extends the earlier results of Bechmann-Pasquinucci et al. and Chau by concluding that all quantum string seals are insecure. Specifically, I find a way to obtain non-trivial available information on the string that escapes the verifier's detection with at least 50% chance.
description: 8 pages with 2 figures, significantly expanded with a few new results, to appear in PRA
Modelling a $2.5 \, M_{\odot}$ Compact Star with Quark Matter
Creators: name: Horvath, J. E.
name: Moraes, P. H. R. S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The detection of an unexpected $\sim 2.5 M_{\odot}$ component in the gravitational wave event GW190814 has puzzled the community of High-Energy astrophysicists, since in the absence of further information it is not clear whether this is the heaviest "neutron star" ever detected or either the lightest black hole known, of a kind absent in the local neighbourhood. We show in this work a few possibilities for a model of the former, in the framework of three different quark matter models with and without anisotropy in the interior pressure. As representatives of classes of "exotic" solutions, we show that even though the stellar sequences may reach this ballpark, it is difficult to fulfill simultaneously the constraint of the radius as measured by the NICER team for the pulsar PSR J0030+0451. Thus, and assuming both measurements stand, compact neutron stars can not be all made of self-bound quark matter, even within anisotropic solutions which boost the maximum mass well above the $\sim 2.5 M_{\odot}$ figure. We also point out that a very massive compact star will limit the absolute maximum matter density in the present Universe to be less than 6 times the nuclear saturation value.
description: To appear in IJMPD, references added