cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Improving the RPC rate capability
Creators: name: Aielli, G.
name: Camarri, P.
name: Cardarelli, R.
name: Di Ciaccio, A.
name: Di Stante, L.
name: Iuppa, R.
name: Liberti, B.
name: Paolozzi, L.
name: Pastori, E.
name: Santonico, R.
name: Toppi, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This paper has the purpose to study the rate capability of the Resistive Plate Chamber, RPC, starting from the basic physics of this detector. The effect of different working parameters determining the rate capability is analysed in detail, in order to optimize a new family of RPCs for applications to heavy irradiation environments and in particular to the LHC phase 2. A special emphasis is given to the improvement achievable by minimizing the avalanche charge delivered in the gas. The paper shows experimental results of Cosmic Ray tests, performed to study the avalanche features for different gas gap sizes, with particular attention to the overall delivered charge. For this purpose, the paper studies, in parallel to the prompt electronic signal, also the ionic signal which gives the main contribution to the delivered charge. Whenever possible the test results are interpreted on the base of the RPC detector physics and are intended to extend and reinforce our physical understanding of this detector.
description: Submitted to JINST Journal of Instrumentation for pubblication
Application of STANDARDS in Bill of Manufacture
Creators: name: Chang, Stephen W. F.
Publisher: name: Monash University
Year: 2022

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.
Far-Field Expansions for Harmonic Maps and the Electrostatics Analogy in Nematic Suspensions
Creators: name: Alama, Stan
name: Bronsard, Lia
name: Lamy, Xavier
name: Venkatraman, Raghavendra
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: For a smooth bounded domain $G\subset\mathbb{R}^3$ we consider maps $n\colon\mathbb R^3\setminus G\to\mathbb S^2$ minimizing the energy $E(n)=\int_{\mathbb R^3\setminus G}|\nabla n|^2 +F_s(n_{\lfloor\partial G})$ among $\mathbb S^2$-valued map such that $n(x)\approx n_0$ as $|x|\to\infty$. This is a model for a particle $G$ immersed in nematic liquid crystal. The surface energy $F_s$ describes the anchoring properties of the particle, and can be quite general. We prove that such minimizing map $n$ has an asymptotic expansion in powers of $1/r$. Further, we show that the leading order $1/r$ term is uniquely determined by the far-field condition $n_0$ for almost all $n_0\in\mathbb S^2$, by relating it to the gradient of the minimal energy with respect to $n_0$. We derive various consequences of this relation in physically motivated situations: when the orientation of the particle $G$ is stable relative to a prescribed far-field alignment $n_0$; and when the particle $G$ has some rotational symmetries. In particular, these corollaries justify some approximations that can be found in the physics literature to describe nematic suspensions via a so-called electrostatics analogy.
description: 18 pages, no figures. Final version to appear in J. Nonlin. Sc
Mobile Device Association and Resource Allocation in Small-Cell IoT Networks with Mobile Edge Computing and Caching
Creators: name: Zhou, Tianqing
name: Yue, Yali
name: Qin, Dong
name: Nie, Xuefang
name: Li, Xuan
name: Li, Chunguo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Theory (cs.IT)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: To meet the need of computation-sensitive (CS) and high-rate (HR) communications, the framework of mobile edge computing and caching has been widely regarded as a promising solution. When such a framework is implemented in small-cell IoT (Internet of Tings) networks, it is a key and open topic how to assign mobile edge computing and caching servers to mobile devices (MDs) with CS and HR communications. Since these servers are integrated into small base stations (BSs), the assignment of them refers to not only the BS selection (i.e., MD association), but also the selection of computing and caching modes. To mitigate the network interference and thus enhance the system performance, some highly-effective resource partitioning mechanisms are introduced for access and backhaul links firstly. After that a problem with minimizing the sum of MDs' weighted delays is formulated to attain a goal of joint MD association and resource allocation under limited resources. Considering that the MD association and resource allocation parameters are coupling in such a formulated problem, we develop an alternating optimization algorithm according to the coalitional game and convex optimization theorems. To ensure that the designed algorithm begins from a feasible initial solution, we develop an initiation algorithm according to the conventional best channel association, which is used for comparison and the input of coalition game in the simulation. Simulation results show that the algorithm designed for minimizing the sum of MDs' weighted delays may achieve a better performance than the initiation (best channel association) algorithm in general.
On $1$d quadratic Klein-Gordon equations with a potential and symmetries
Creators: name: Germain, Pierre
name: Pusateri, Fabio
name: Zhang, Katherine Zhiyuan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35Q55, 35B34

description: This paper is a continuation of a previous work Germain-Pusateri (2020) by the first two authors. We focus on $1$ dimensional quadratic Klein-Gordon equations with a potential, under some assumptions that are less general than Germain-Pusateri (2020), but allow us to present some simplifications in the proof of global existence with decay for small solutions. In particular, we can propagate a stronger control on a basic $L^2$-weighted type norm while providing some shorter and less technical proofs for some of the arguments.
Viborg Museum research approval letter from Ancient Y. pestis genomes lack the virulence-associated YpfΦ prophage present in modern pandemic strains
Creators: name: Bonczarowska, Joanna H.
name: Susat, Julian
name: Krause-Kyora, Ben
name: Dangvard Pedersen, Dorthe
name: Boldsen, Jesper
name: Agersnap Larsen, Lars
name: Seeberg, Lone
name: Nebel, Almut
name: Unterweger, Daniel
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Health Care
subject: Diseases
classificationCode: 111706
subject: Epidemiology
classificationCode: 60408
subject: Genomics

description: Letter of approval for research on the medieval/early modern skeletal remains from Viborg, Denmark.
INAQS, a generic interface for non-adiabatic QM/MM dynamics: Design, implementation, and validation for GROMACS/Q-CHEM simulations
Creators: name: Cofer-Shabica, D. Vale
name: Menger, Maximilian F. S. J.
name: Ou, Qi
name: Shao, Yihan
name: Subotnik, Joseph E.
name: Faraji, Shirin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The accurate description of large molecular systems in complex environments remains an ongoing challenge for the field of computational chemistry. This problem is even more pronounced for photo-induced processes, as multiple excited electronic states and their corresponding non-adiabatic couplings must be taken into account. Multiscale approaches such as hybrid quantum mechanics/molecular mechanics (QM/MM) offer a balanced compromise between accuracy and computational burden. Here, we introduce an open-source software package (INAQS) for non-adiabatic QM/MM simulations that bridges the sampling capabilities of the GROMACS MD package and the excited-state infrastructure of the Q-CHEM electronic structure software. The interface is simple and can be adapted easily to other MD codes. The code supports a variety of different trajectory based molecular dynamics, ranging from Born-Oppenheimer to surface hopping dynamics. To illustrate the power of this combination, we simulate electronic absorption spectra, free energy surfaces along a reaction coordinate, and the excited state dynamics of 1,3-cyclohexadiene in solution.
description: 45 pages, 7 figures
Low Overhead RF Impedance Measurement by Using Periodic Structures
Creators: name: Avci, Muslum Emir
name: Ozev, Sule
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Due to the need for higher reliability and performance from RF circuits, multi-port reflectometers are increasingly used as low-overhead impedance monitors. In this work, using periodic structures as multi-ports is proposed. Periodic structures impose a new constraint on the multi-port theory and simplify it significantly. This simplification leads to closed form solution for calibration and measurement procedures. The closed-form solution also shows that any arbitrary periodic structure will always have a unique solution for both procedures. Therefore, the proposed technique does not rely on frequency-dependent behavior of devices, such as directivity and phase shift to measure impedance. This fact leads to increased bandwidth and simplified design procedure. In addition, proposed multi-port structures can be calibrated by using fewer known loads than existing multi-port techniques. This fact, coupled with the closed-form solution, reduces computation overhead and test time. The theory and its robustness against non-idealities, such as part-to-part variation, are verified with Monte-Carlo simulations. A practical embodiment of the technique is demonstrated with EM simulations and hardware experiments. In this embodiment, the multi-port structure is embedded into an LC matching network. Hardware experiments show that the embedded multi-port structure can measure test loads with high accuracy from 1.5 GHz to 3.5 GHz, without degrading matching network performance.
Perturbations in Non-Flat Cosmology for $f(T)$ gravity
Creators: name: Bahamonde, Sebastian
name: Dialektopoulos, Konstantinos F.
name: Hohmann, Manuel
name: Said, Jackson Levi
name: Pfeifer, Christian
name: Saridakis, Emmanuel N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The study of cosmological perturbation theory in $f(T)$ gravity is a topic of great interest in teleparallel gravity since this is one of the simplest generalizations of the theory that modifies the teleparallel equivalent of general relativity. In this work, we explore the possibility of a non-flat FLRW background solution and perform perturbations for positively as well as negatively curved spatial geometries, together with a comparison to the flat case. We determine the generalized behaviour of the perturbative modes for this non-flat FLRW setting for arbitrary $f(T)$ models, when the most general homogeneous and isotropic background tetrads are used. We also identify propagating modes in this setup, and relate this with the case of a flat cosmology.
description: 21 pagers, no figures
Local atomic and magnetic structure of dilute magnetic semiconductor (Ba,K)(Zn,Mn)$_2$As$_2$
Creators: name: Frandsen, Benjamin A.
name: Gong, Zizhou
name: Terban, Maxwell
name: Banerjee, Soham
name: Chen, Bijuan
name: Jin, Changqing
name: Feygenson, Mikhail
name: Uemura, Yasutomo J.
name: Billinge, Simon J. L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have studied the atomic and magnetic structure of the dilute ferromagnetic semiconductor system (Ba,K)(Zn,Mn)$_2$As$_2$ through atomic and magnetic pair distribution function analysis of temperature-dependent x-ray and neutron total scattering data. We detected a change in curvature of the temperature-dependent unit cell volume of the average tetragonal crystallographic structure at a temperature coinciding with the onset of ferromagnetic order. We also observed the existence of a well-defined local orthorhombic structure on a short length scale of $\lesssim 5$ Å, resulting in a rather asymmetrical local environment of the Mn and As ions. Finally, the magnetic PDF revealed ferromagnetic alignment of Mn spins along the crystallographic $c$-axis, with robust nearest-neighbor ferromagnetic correlations that exist even above the ferromagnetic ordering temperature. We discuss these results in the context of other experiments and theoretical studies on this system.
Deuteron structure in the deep inelastic regime
Creators: name: Canal, C. A. Garcìa
name: Tarutina, T.
name: Vento, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study nuclear effects on the deuteron in the deep inelastic regime using the newest available data analyzing their $Q^2$ dependence. We conclude that precise EMC ratios for large $Q^2$ (> 30, GeV$^2$) cannot be obtained without considering these nuclear effects. For this purpose we use a scheme which parametrizes these effects in a simple manner and compare our results with other recent proposals.
description: 10 pages, 4 figures
The Connection Between Reddening, Gas Covering Fraction, and the Escape of Ionizing Radiation at High Redshift
Creators: name: Reddy, Naveen A.
name: Steidel, Charles C.
name: Pettini, Max
name: Bogosavljevic, Milan
name: Shapley, Alice
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use a large sample of galaxies at z~3 to establish a relationship between reddening, neutral gas covering fraction (fcov(HI)), and the escape of ionizing photons at high redshift. Our sample includes 933 galaxies at z~3, 121 of which have very deep spectroscopic observations (>7 hrs) in the rest-UV (lambda=850-1300 A) with Keck/LRIS. Based on the high covering fraction of outflowing optically-thick HI indicated by the composite spectra of these galaxies, we conclude that photoelectric absorption, rather than dust attenuation, dominates the depletion of ionizing photons. By modeling the composite spectra as the combination of an unattenuated stellar spectrum including nebular continuum emission with one that is absorbed by HI and reddened by a line-of-sight extinction, we derive an empirical relationship between E(B-V) and fcov(HI). Galaxies with redder UV continua have larger covering fractions of HI characterized by higher line-of-sight extinctions. Our results are consistent with the escape of Lya through gas-free lines-of-sight. Covering fractions based on low-ionization interstellar absorption lines systematically underpredict those deduced from the HI lines, suggesting that much of the outflowing gas may be metal-poor. We develop a model which connects the ionizing escape fraction with E(B-V), and which may be used to estimate the escape fraction for an ensemble of high-redshift galaxies. Alternatively, direct measurements of the escape fraction for our data allow us to constrain the intrinsic 900-to-1500 A flux density ratio to be >0.20, a value that favors stellar population models that include weaker stellar winds, a flatter initial mass function, and/or binary evolution. Lastly, we demonstrate how the framework discussed here may be used to assess the pathways by which ionizing radiation escapes from high-redshift galaxies. [Abridged]
description: 22 pages, 3 tables, 14 figures, accepted to the Astrophysical Journal
Non-hermitian Dirac Hamiltonian in the presence of local Fermi velocity
Creators: name: Ghosh, Rahul
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We present a new approach to study a class of non-Hermitian (1+1)-dimensional Dirac Hamiltonian in the presence of local Fermi velocity. We apply the well known Nikiforov-Uvarov method to solve such a system. We discuss applications and explore the solvability of both $\mathcal{PT}$-symmetric and non-$\mathcal{PT}$ symmetric classes of potentials. In the former case we obtain the solution of a harmonic oscillator in the presence of a linear vector potential while in the latter case we solve the shifted harmonic oscillator problem.
description: Accepted in International Journal of Modern Physics A (12 pages)
CRYPTOCOMPONENT: UM COMPONENTE DE CRIPTOGRAFIA PARA SISTEMAS DE SOFTWARE IOT COM DISPOSITIVOS DE BAIXO CUSTO
Creators: name: de Paiva, Bruno
name: de Souza, Bruno
name: Travassos, Guilherme
Publisher: name: Zenodo
Year: 2023
Subjects: internet das coisas
segurança
criptografia
dados
sistemas de software contemporâneos
engenharia de software experimental

description: O grande número de dispositivos de sistemas de software IoT motivados pelo avanço da Indústria 4.0 levou organizações a listar os riscos de segurança mais comuns. A transferência segura de dados e o armazenamento de informações estão entre os dez problemas mais frequentes nesses dispositivos IoT. Portanto, este trabalho apresenta um componente de criptografia que permite que dispositivos com baixo poder computacional transmitam dados seguramente, contribuindo para mitigar a falta de segurança nestes sistemas. Esse componente foi avaliado em dois estudos experimentais para verificar sua viabilidade e eficiência. Os resultados sugerem que o componente apresenta um desempenho adequado quando encapsulado em um sistema de software IoT de baixo custo.
The usability canary in the security coal mine: A cognitive framework for evaluation and design of usable authentication solutions
Creators: name: Glass, Brain
name: Jenkinson, Graeme
name: Liu, Yuqi
name: Sasse, M. Angela
name: Stajano, Frank
Publisher: name: arXiv
Year: 2016
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Over the past 15 years, researchers have identified an increasing number of security mechanisms that are so unusable that the intended users either circumvent them or give up on a service rather than suffer the security. With hindsight, the reasons can be identified easily enough: either the security task itself is too cumbersome and/or time-consuming, or it creates high friction with the users` primary task. The aim of the research presented here is to equip designers who select and implement security mechanisms with a method for identifying the ``best fit`` security mechanism at the design stage. Since many usability problems have been identified with authentication, we focus on ``best fit`` authentication, and present a framework that allows security designers not only to model the workload associated with a particular authentication method, but more importantly to model it in the context of the user`s primary task. We draw on results from cognitive psychology to create a method that allows a designer to understand the impact of a particular authentication method on user productivity and satisfaction. In a validation study using a physical mockup of an airline check-in kiosk, we demonstrate that the model can predict user performance and satisfaction. Furthermore, design experts suggested personalized order recommendations which were similar to our model`s predictions. Our model is the first that supports identification of a holistic fit between the task of user authentication and the context in which it is performed. When applied to new systems, we believe it will help designers understand the usability impact of their security choices and thus develop solutions that maximize both.
Scale-invariance at the core of quantum black holes
Creators: name: Borissova, Johanna N.
name: Held, Aaron
name: Afshordi, Niayesh
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study spherically-symmetric solutions to a modified Einstein-Hilbert action with Renormalization Group scale-dependent couplings, inspired by Weinberg's Asymptotic Safety scenario for Quantum Gravity. The Renormalization Group scale is identified with the Tolman temperature for an isolated gravitational system in thermal equilibrium with Hawking radiation. As a result, the point of infinite local temperature is shifted from the classical black-hole horizon to the origin and coincides with a timelike curvature singularity. Close to the origin, the spacetime is determined by the scale-dependence of the cosmological constant in the vicinity of the Reuter fixed point: the free components of the metric can be derived analytically and are characterized by a radial power law with exponent $α= \sqrt{3}-1$. Away from the fixed point, solutions for different masses are studied numerically and smoothly interpolate between the Schwarzschild exterior and the scale-invariant interior. Whereas the exterior of objects with astrophysical mass is described well by vacuum General Relativity, deviations become significant at a Planck distance away from the classical horizon and could lead to observational signatures. We further highlight potential caveats in this intriguing result with regard to our choice of scale-identification and identify future avenues to better understand quantum black holes in relation to the key feature of scale-invariance.
description: v2: 20 pages + appendix; clarifications and references added; matches version accepted for publication
Gaussian process regression can turn non-uniform and undersampled diffusion MRI data into diffusion spectrum imaging
Creators: name: Sjölund, Jens
name: Eklund, Anders
name: Özarslan, Evren
name: Knutsson, Hans
Publisher: name: arXiv
Year: 2016
Subjects: subject: Applications (stat.AP)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We propose to use Gaussian process regression to accurately estimate the diffusion MRI signal at arbitrary locations in q-space. By estimating the signal on a grid, we can do synthetic diffusion spectrum imaging: reconstructing the ensemble averaged propagator (EAP) by an inverse Fourier transform. We also propose an alternative reconstruction method guaranteeing a nonnegative EAP that integrates to unity. The reconstruction is validated on data simulated from two Gaussians at various crossing angles. Moreover, we demonstrate on non-uniformly sampled in vivo data that the method is far superior to linear interpolation, and allows a drastic undersampling of the data with only a minor loss of accuracy. We envision the method as a potential replacement for standard diffusion spectrum imaging, in particular when acquistion time is limited.
description: 5 pages
Understanding Jupiter's Interior
Creators: name: Militzer, Burkhard
name: Soubiran, Francois
name: Wahl, Sean M.
name: Hubbard, William
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: This article provides an overview of how models of giant planet interiors are constructed. We review measurements from past space missions that provide constraints for the interior structure of Jupiter. We discuss typical three-layer interior models that consist of a dense central core and an inner metallic and an outer molecular hydrogen-helium layer. These models rely heavily on experiments, analytical theory, and first-principle computer simulations of hydrogen and helium to understand their behavior up to the extreme pressures ~10 Mbar and temperatures ~10,000 K. We review the various equations of state used in Jupiter models and compare them with shock wave experiments. We discuss the possibility of helium rain, core erosion and double diffusive convection may have important consequences for the structure and evolution of giant planets. In July 2016 the Juno spacecraft entered orbit around Jupiter, promising high-precision measurements of the gravitational field that will allow us to test our understanding of gas giant interiors better than ever before.
description: 13 pages, 11 figures in J. Geophys. Research - Planets, 2016
NFDI4Chem Terminology Service: Enabling semantic research data interoperability, discovery and exploitation in chemistry
Creators: name: Nainala, Chandu
name: Strömert, Philip
Publisher: name: Zenodo
Year: 2022

description: NFDI4Chem is an initiative to build an open and FAIR infrastructure for research data management in chemistry. The TS is a central part of the NFDI4Chem infrastructure that is currently in the making and which serves as the single point of access for NFDI4Chem services that use terminologies, controlled vocabularies or ontologies. Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under the National Research Data Infrastructure – NFDI4Chem – Projektnummer 441958208.
Approximate Acoustic Boundary Conditions in the Time-Domain using Volume Penalization
Creators: name: Lemke, Mathias
name: Reiss, Julius
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Immersed boundary methods allow describing complex objects on simple Cartesian grids in time-domain simulations. The penalization technique employed here is a physically motivated Brinkman method that models objects as porous material by including a friction term and an effective volume. We investigate how the approach can mimic different acoustic boundary conditions. It is validated concerning different acoustic setups, including rigid walls and various absorber configurations.
Self-induced glassiness and pattern formation in spin systems subject to long-range interactions
Creators: name: Principi, Alessandro
name: Katsnelson, Mikhail I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the glass formation in two- and three-dimensional Ising and Heisenberg spin systems subject to competing interactions and uniaxial anisotropy with a mean-field approach. In three dimensions, for sufficiently strong anisotropy the systems always modulates in a striped phase. Below a critical strength of the anisotropy, a glassy phase exists in a finite range of temperature, and it becomes more stable as the system becomes more isotropic. In two dimension the criticality is always avoided and the glassy phase always exists.
description: 4 pages, 4 figures
Four-dimensional equation of motion for viscous compressible and charged fluid with regard to the acceleration field, pressure field and dissipation field
Creators: name: Fedosin, Sergey G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: From the principle of least action the equation of motion for viscous compressible and charged fluid is derived. The viscosity effect is described by the 4-potential of the energy dissipation field, dissipation tensor and dissipation stress-energy tensor. In the weak field limit it is shown that the obtained equation is equivalent to the Navier-Stokes equation. The equation for the power of the kinetic energy loss is provided, the equation of motion is integrated, and the dependence of the velocity magnitude is determined. A complete set of equations is presented, which suffices to solve the problem of motion of viscous compressible and charged fluid in the gravitational and electromagnetic fields.
description: 29 pages
Dark matter as seen from the physical point of view
Creators: name: Krasnoholovets, Vlodymyr
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: It is shown that the Newton's law of universal gravitation can be derived from first submicroscopic principles inherent in the very nature of real space that is constituted as a tessellattice of primary topological balls. The submicroscopic concept determines the notion of mass in the tessellattice and introduces excitations of space, which appear at the motion of particles (mass particles are determined as local deformations of the tessellattice). These excitations are associated with carriers of the field of inertia. In the universe the gravitation is induced by standing inerton waves of mass objects, which oscillate around the objects with the speed of light. An overlapping of these standing inerton waves generates an elastic interaction between masses bringing them to a formation of clusters in which masses are characterised by both the Newtonian and elastic interaction. It is this elastic interaction that cancels the necessity of introduction of mystical dark matter. At the same time, inertons, carriers of inert properties of objects, can be treated as an analogous of hypothetic weakly interacting massive particles (WIMP) or axions, which some astronomers try to associate with dark matter particles.
description: 16 pages, 2 figures, 30 Refs
Markov models of treatment options and expectations in a renal program
Creators: name: Smarrelli, Pasqualine.
Publisher: name: Monash University
Year: 2022

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 Posteriori Estimates of Taylor-Hood Element for Stokes Problem Using Auxiliary Subspace Techniques
Creators: name: Zhang, Jiachuan
name: Zhang, Ran
name: Wang, Xiaoshen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: Based on the auxiliary subspace techniques, a hierarchical basis a posteriori error estimator is proposed for the Stokes problem in two and three dimensions. For the error estimator, we need to solve only two global diagonal linear systems corresponding to the degree of freedom of velocity and pressure respectively, which reduces the computational cost sharply. The upper and lower bounds up to an oscillation term of the error estimator are also shown to address the reliability of the adaptive method without saturation assumption. Numerical simulations are performed to demonstrate the effectiveness and robustness of our algorithm.
Using ForeCAT Deflections and Rotations to Constrain the Early Evolution of CMEs
Creators: name: Kay, C.
name: Opher, M.
name: Colaninno, R. C.
name: Vourlidas, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: To accurately predict the space weather effects of coronal mass ejection (CME) impacts at Earth one must know if and when a CME will impact Earth, and the CME parameters upon impact. Kay et al. (2015b) presents Forecasting a CME's Altered Trajectory (ForeCAT), a model for CME deflections based on the magnetic forces from the background solar magnetic field. Knowing the deflection and rotation of a CME enables prediction of Earth impacts, and the CME orientation upon impact. We first reconstruct the positions of the 2008 April 10 and the 2012 July 12 CMEs from the observations. The first of these CMEs exhibits significant deflection and rotation (34 degrees deflection and 58 degrees rotation), while the second shows almost no deflection or rotation (<3 degrees each). Using ForeCAT, we explore a range of initial parameters, such as the CME location and size, and find parameters that can successfully reproduce the behavior for each CME. Additionally, since the deflection depends strongly on the behavior of a CME in the low corona (Kay et al. (2015a, 2015b)), we are able to constrain the expansion and propagation of these CMEs in the low corona.
description: accepted in ApJ
No overdensity of Lyman Alpha Emitting Galaxies around a quasar at z~5.7
Creators: name: Mazzucchelli, C.
name: Bañados, E.
name: Decarli, R.
name: Farina, E. P.
name: Venemans, B. P.
name: Walter, F.
name: Overzier, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Bright quasars, observed when the Universe was less than one billion years old (z>5.5), are known to host massive black holes (~10$^{9}$ M$_{\odot}$), and are thought to reside in the center of massive dark matter overdensities. In this picture, overdensities of galaxies are expected around high redshift quasars. However, observations based on the detection of Lyman Break Galaxies (LBGs) around these quasars do not offer a clear picture: this may be due to the uncertain redshift constraints of LBGs, which are selected through broad-band filters only. To circumvent such uncertainties, we here perform a search for Lyman Alpha Emitting galaxies (LAEs) in the field of the quasar PSO J215.1512-16.0417 at z~5.73, through narrow band, deep imaging with FORS2 at the VLT. We study an area of 37 arcmin$^{2}$, i.e. ~206 comoving Mpc$^{2}$ at the redshift of the quasar. We find no evidence for an overdensity of LAEs in the quasar field with respect to blank field studies. Possible explanations for these findings include that our survey volume is too small, or that the strong ionizing radiation from the quasar hinders galaxy formation in its immediate proximity. Another possibility is that these quasars are not situated in the dense environments predicted by some simulations.
description: Accepted by ApJ
Magnetic Field Prediction Using Generative Adversarial Networks
Creators: name: Pollok, Stefan
name: Olden-Jørgensen, Nataniel
name: Jørgensen, Peter Stanley
name: Bjørk, Rasmus
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Plenty of scientific and real-world applications are built on magnetic fields and their characteristics. To retrieve the valuable magnetic field information in high resolution, extensive field measurements are required, which are either time-consuming to conduct or even not feasible due to physical constraints. To alleviate this problem, we predict magnetic field values at a random point in space from a few point measurements by using a generative adversarial network (GAN) structure. The deep learning (DL) architecture consists of two neural networks: a generator, which predicts missing field values of a given magnetic field, and a critic, which is trained to calculate the statistical distance between real and generated magnetic field distributions. By minimizing this statistical distance, a reconstruction loss as well as physical losses, our trained generator has learned to predict the missing field values with a median reconstruction test error of 5.14%, when a single coherent region of field points is missing, and 5.86%, when only a few point measurements in space are available and the field measurements around are predicted. We verify the results on an experimentally validated field.
description: 10 pages, 12 figures
Nonvolatile Multi-level Memory and Boolean Logic Gates Based on a Single Memtranstor
Creators: name: Shen, Jianxin
name: Shang, Dashan
name: Chai, Yisheng
name: Wang, Yue
name: Cong, Junzhuang
name: Shen, Shipeng
name: Yan, Liqin
name: Wang, Wenhong
name: Sun, Young
Publisher: name: arXiv
Year: 2016
Subjects: subject: Emerging Technologies (cs.ET)
subject: FOS: Computer and information sciences

description: Memtranstor that correlates charge and magnetic flux via nonlinear magnetoelectric effects has a great potential in developing next-generation nonvolatile devices. In addition to multi-level nonvolatile memory, we demonstrate here that nonvolatile logic gates such as NOR and NAND can be implemented in a single memtranstor made of the Ni/PMN-PT/Ni heterostructure. After applying two sequent voltage pulses (X1, X2) as the logic inputs on the memtranstor, the output magnetoelectric voltage can be positive high (logic "1"), positive low (logic "0"), or negative (logic "0"), depending on the levels of X1 and X2. The underlying physical mechanism is related to the complete or partial reversal of ferroelectric polarization controlled by inputting selective voltage pulses, which determines the magnitude and sign of the magnetoelectric voltage coefficient. The combined functions of both memory and logic could enable the memtranstor as a promising candidate for future computing systems beyond von Neumann architecture.
description: 8 pages, 5 figures
Forecasting with time series and structural models : an Australian case
Creators: name: Wong, Koi N.
Publisher: name: Monash University
Year: 2022

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.
On infrared problems of effective Lagrangians of massive spin 2 fields coupled to gauge fields
Creators: name: Canfora, Fabrizio
name: Giacomini, Alex
name: Zerwekh, Alfonso R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper we analyze the interactions of a massive spin-2 particles charged under both Abelian and non-Abelian group using the Porrati-Rahman Lagrangian. This theory is valid up to an intrinsic cutoff scale. Phenomenologically a theory valid up to a cutoff scale is sensible as all known higher spin particles are non-fundamental and it is shown that indeed this action can be used to estimate some relevant cross section. Such action necessarily includes Stuckelberg field and therefore it is necessary to fix the corresponding gauge symmetry. We show that this theory, when the Stuckelberg symmetry is gauge-fixed, possesses a non-trivial infrared problem. A gauge fixing ambiguity arises which is akin to the Gribov problem in QCD in the Abelian case as well. In some cases (such as when the space-time is the four-dimensional torus) the vacuum copies can be found analytically. A similar phenomenon also appears in the case of Proca fields. A very interesting feature of these copies is that they arise only for "large enough" gauge potentials. This opens the possibility to avoid the appearance of such gauge fixing ambiguities by using a Gribov-Zwanziger like approach.
description: Version accepted for publication in Nuclear Physics B
Refined universal laws for hull volumes and perimeters in large planar maps
Creators: name: Guitter, Emmanuel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We consider ensembles of planar maps with two marked vertices at distance k from each other and look at the closed line separating these vertices and lying at distance d from the first one (d
description: 28 pages, 14 figures
On Local Domain Symmetry for Model Expansion
Creators: name: Devriendt, Jo
name: Bogaerts, Bart
name: Bruynooghe, Maurice
name: Denecker, Marc
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Symmetry in combinatorial problems is an extensively studied topic. We continue this research in the context of model expansion problems, with the aim of automating the workflow of detecting and breaking symmetry. We focus on local domain symmetry, which is induced by permutations of domain elements, and which can be detected on a first-order level. As such, our work is a continuation of the symmetry exploitation techniques of model generation systems, while it differs from more recent symmetry breaking techniques in answer set programming which detect symmetry on ground programs. Our main contributions are sufficient conditions for symmetry of model expansion problems, the identification of local domain interchangeability, which can often be broken completely, and efficient symmetry detection algorithms for both local domain interchangeability as well as local domain symmetry in general. Our approach is implemented in the model expansion system IDP, and we present experimental results showcasing the strong and weak points of our approach compared to SBASS , a symmetry breaking technique for answer set programming.
description: Paper presented at the 32nd International Conference on Logic Programming (ICLP 2016), New York City, USA, 16-21 October 2016, 15 pages, LaTeX, 3 PDF figures (arXiv:YYMM.NNNNN)
Tunneling into quantum wires: regularization of the tunneling Hamiltonian and consistency between free and bosonized fermions
Creators: name: Filippone, Michele
name: Brouwer, Piet
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Tunneling between a point contact and a one-dimensional wire is usually described with the help of a tunneling Hamiltonian that contains a delta function in position space. Whereas the leading order contribution to the tunneling current is independent of the way this delta function is regularized, higher-order corrections with respect to the tunneling amplitude are known to depend on the regularization. Instead of regularizing the delta function in the tunneling Hamiltonian, one may also obtain a finite tunneling current by invoking the ultraviolet cut-offs in a field-theoretic description of the electrons in the one-dimensional conductor, a procedure that is often used in the literature. For the latter case, we show that standard ultraviolet cut-offs lead to different results for the tunneling current in fermionic and bosonized formulations of the theory, when going beyond leading order in the tunneling amplitude. We show how to recover the standard fermionic result using the formalism of functional bosonization and revisit the tunneling current to leading order in the interacting case.
description: 17 pages, 5 figures
A maximum-entropy model to predict 3D structural ensembles of chromatins from pairwise distances: Applications to Interphase Chromosomes and Structural Variants
Creators: name: Shi, Guang
name: Thirumalai, D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: Biomolecules (q-bio.BM)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The principles that govern the organization of genomes, which are needed for a deeper understanding of how chromosomes are packaged and function in eukaryotic cells, could be deciphered if the three-dimensional (3D) structures are known. Recently, single-cell imaging experiments have determined the 3D coordinates of a number of loci in a chromosome. Here, we introduce a computational method (Distance Matrix to Ensemble of Structures, DIMES), based on the maximum entropy principle, with experimental pair-wise distances between loci as constraints, to generate a unique ensemble of 3D chromatin structures. Using the ensemble of structures, we quantitatively account for the distribution of pair-wise distances, three-body co-localization and higher-order interactions. We demonstrate that the DIMES method can be applied to both small length-scale and chromosome-scale imaging data to quantify the extent of heterogeneity and fluctuations in the shapes on various length scales. We develop a perturbation method that is used in conjunction with DIMES to predict the changes in 3D structures from structural variations. Our method also reveals quantitative differences between the 3D structures inferred from Hi-C and the ones measured in imaging experiments. Finally, the physical interpretation of the parameters extracted from DIMES provides insights into the origin of phase separation between euchromatin and heterochromatin domains.
Tunable photon-induced spatial modulation of free electrons
Creators: name: Tsesses, Shai
name: Dahan, Raphael
name: Wang, Kangpeng
name: Reinhardt, Ori
name: Bartal, Guy
name: Kaminer, Ido
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Spatial modulation of electron beams is an essential tool for various applications such as nanolithography and imaging, yet its implementations are severely limited and inherently non-tunable. Conversely, light-driven electron spatial modulation could potentially allow arbitrary electron wavefront shaping via the underlying mechanism of photon-induced near-field electron microscopy (PINEM). Here, we present tunable photon-induced spatial modulation of electrons through their externally-controlled interaction with surface plasmon polaritons (SPPs). Using recently developed methods of shaping SPP patterns, we demonstrate a dynamic control of the electron beam with a variety of high-quality electron distributions. Intriguingly, by utilizing the intrinsic interaction nonlinearity, we attain the first observation of 2D spatial Rabi oscillations and generate electron features below the SPP wavelength. Our work paves the way to on-demand electron wavefront shaping at ultrafast timescales, with prospects for aberration correction, nano-fabrication and material characterization.
Analytic treatment and parameter values from Cooperative melting in double-stranded peptide chains through local mechanical interactions
Creators: name: Bellino, Luca
name: Florio, Giuseppe
name: Goriely, Alain
name: Puglisi, Giuseppe
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Biophysics
subject: Biochemistry
classificationCode: 110601
subject: Biomechanics

description: The file contains details on the computation as well as table of parameters extracted from the literature
A casual VARMA model of the Australian economy
Creators: name: Jackson, Julie.
Publisher: name: Monash University
Year: 2022

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.