cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Surrogate- and invariance-boosted contrastive learning for data-scarce applications in science
Creators: name: Loh, Charlotte
name: Christensen, Thomas
name: Dangovski, Rumen
name: Kim, Samuel
name: Soljacic, Marin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Deep learning techniques have been increasingly applied to the natural sciences, e.g., for property prediction and optimization or material discovery. A fundamental ingredient of such approaches is the vast quantity of labelled data needed to train the model; this poses severe challenges in data-scarce settings where obtaining labels requires substantial computational or labor resources. Here, we introduce surrogate- and invariance-boosted contrastive learning (SIB-CL), a deep learning framework which incorporates three ``inexpensive'' and easily obtainable auxiliary information sources to overcome data scarcity. Specifically, these are: 1)~abundant unlabeled data, 2)~prior knowledge of symmetries or invariances and 3)~surrogate data obtained at near-zero cost. We demonstrate SIB-CL's effectiveness and generality on various scientific problems, e.g., predicting the density-of-states of 2D photonic crystals and solving the 3D time-independent Schrodinger equation. SIB-CL consistently results in orders of magnitude reduction in the number of labels needed to achieve the same network accuracies.
description: 21 pages, 10 figures
A stretched exponential-based approach for the magnetic properties of spin glasses
Creators: name: Bufaiçal, Leandro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The spin glasses show intriguing characteristic features that are not well understood yet, as for instance its aging, rejuvenation and memory effects. Here a model based on a stretched exponential decay of its magnetization is proposed, which can describe the main magnetic features of spin glasses observed in experiments as the time-decay of thermoremament magnetization, the relaxation of zero field cooled magnetization, the ac and dc magnetization as a function of temperature and others. In principle, the here proposed model could be adapted to describe other glassy systems.
description: 5 pages, 5 figures + supplementary material. Title changed
title: Study of rainout effect on the heating of water-based humidifiers and related alarms
title: Μελέτη της επίδρασης του φαινομένου rainout στη θέρμανση των υγραντήρων νερού και οι σχετικοί συναγερμοί
titleType: AlternativeTitle
Creators: name: Σκουρή, Μαρία
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Active humidification
ICU
Non-invasive ventilation
Humidifier
Nebulizer
Water condensation
Alarm fatigue

description: The of this thesis project is to establish the consequences of the rainout effect on the performance of a MR850 humidifier using a mesh nebulizer and during non-invasive mechanical ventilation. A basic breathing circuit used for ICU patients consists of a ventilator, a heated humidifier and a nebulizer. While heated humidifiers (HH) used with nebulizers are important to prevent problerms in mechanical ventilators, thet can result in the ventilator circuit condensing as well, resulting in occlusion alarms. Temperature, pressure and related alarms were studied with a non-invasive positive pressure ventilator the NIPPV 3+ at different pressure rated. The humidification system was a basic model of heated humidifier the MR850 (Fisher & Paykel, Auckland, NZ), which was a single heated circuit. The nebulization system was a piezoelectric nebulizer, the Aeroneb Pro (Aerogen, IE) which was tested in three nebulizer circuit positions. The circuit was completed with a standard test lung 6006832, Adult 190 (1 Liter) (Maquet, DE). The nebulizer was tested at three positions including at the dry side of the humidifiers, between the Y-piece and the circuit and finally the ventilator outlet. In general, the ressure rate did not dramaticallu affect the number of alamrs during trials. Deepending, on the placement of the nebulizer device, the prespective temperaute is affected and therefore the alarms. \placing the nebulizer far from the temperautre probe of the humidifier, developed significantly fewer alarms that placing it near them. Our results showed that the best position for the placement of the nebulizer is at the ventilator's outlet although the manudacturers do not recommend it. It should be noted, however, that these experiments were conducted in the laboratory and not in a cinical environment, where our findings remain to be confirmed.
Water jet space charge spectroscopy: Route to direct measurement of electron dynamics for organic systems in their natural environment
Creators: name: Mittermair, Michael
name: Martin, Felix
name: Wörle, Martin
name: Bloß, Dana
name: Duensing, Andreas
name: Kienberger, Reinhard
name: Hans, Andreas
name: Iglev, Hristo
name: Knie, André
name: Helml, Wolfram
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The toolbox for time-resolved direct measurements of electron dynamics covers a variety of methods. Since the experimental effort is increasing rapidly with achievable time resolution, there is an urge for simple and robust measurement techniques. Within this paper prove of concept experiments and numerical simulations are utilized to investigate the applicability of a new setup for the generation of ultrashort electron pulses in the energy range of 300 eV up to 1.6 keV. The experimental approach combines an in-vacuum liquid microjet and a few-cycle femtosecond laser system, while the threshold for electron impact ionization serves as a gate for the effective electron pulse duration. The experiments prove that electrons in the keV regime are accessible and that the electron spectrum can be easily tuned by laser intensity and focal position alignment with respect to the water jet. Numerical simulations show that a sub-picosecond temporal resolution is achievable.
description: 13 Pages, 6 Fugures
Crab flares due to turbulent dissipation of the pulsar striped wind
Creators: name: Zrake, Jonathan
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We interpret $γ$-ray flares from the Crab Nebula as the signature of turbulence in the pulsar's electromagnetic outflow. Turbulence is triggered upstream by dynamical instability of the wind's oscillating magnetic field, and accelerates non-thermal particles. On impacting the wind termination shock, those particles emit a distinct synchrotron component $F_{ν,\rm flare}$, which is constantly modulated by intermittency of the upstream plasma flow. Flares are observed when the high-energy cutoff of $F_{ν,\rm flare}$ emerges above the fast-declining nebular emission around 0.1 - 1 GeV. Simulations carried out in the force-free electrodynamics approximation predict the striped wind to become fully turbulent well ahead of the wind termination shock, provided its terminal Lorentz factor is $\lesssim 10^4$.
description: Submitted to ApJ
Regulation of CD4+ T cell responses by the CD28/B7 and ICOS/ICOSL costimulatory pathways and myeloperoxidase
Creators: name: Odobasic., Dragana
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Extreme hitting probabilities for diffusion
Creators: name: Linn, Samantha
name: Lawley, Sean D
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: Biological Physics (physics.bio-ph)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: FOS: Biological sciences
subject: 92C05, 92C37, 92C40, 60G07, 60G40

description: A variety of systems in physics, chemistry, biology, and psychology are modeled in terms of diffusing "searchers" looking for "targets." Examples range from gene regulation, to cell sensing, to human decision-making. A commonly studied statistic in these models is the so-called hitting probability for each target, which is the probability that a given single searcher finds that particular target. However, the decisive event in many systems is not the arrival of a given single searcher to a target, but rather the arrival of the fastest searcher to a target out of many searchers. In this paper, we study the probability that the fastest diffusive searcher hits a given target in the many searcher limit, which we call the extreme hitting probability. We first prove an upper bound for the decay of the probability that the searcher finds a target other than the closest target. This upper bound applies in very general settings and depends only on the relative distances to the targets. Furthermore, we find the exact asymptotics of the extreme hitting probabilities in terms of the short-time distribution of when a single searcher hits a target. These results show that the fastest searcher always hits the closest target in the many searcher limit. While this fact is intuitive in light of recent results on the time it takes the fastest searcher to find a target, our results give rigorous, quantitative estimates for the extreme hitting probabilities. We illustrate our results in several examples and numerical simulations.
description: 37 pages, 7 figures
A Nonlocal Poisson-Fermi Model for Ionic Solvent
Creators: name: Xie, Dexuan
name: Liu, Jinn-Liang
name: Eisenberg, Bob
name: Scott, L. Ridgway
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: Biomolecules (q-bio.BM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences
subject: 41.20.Cv, 77.22.-d, 82.60.Lf, 87.10.Ed

description: We propose a nonlocal Poisson-Fermi model for ionic solvent that includes ion size effects and polarization correlations among water molecules in the calculation of electrostatic potential. It includes the previous Poisson-Fermi models as special cases, and its solution is the convolution of a solution of the corresponding nonlocal Poisson dielectric model with a Yukawa-type kernel function. Moreover, the Fermi distribution is shown to be a set of optimal ionic concentration functions in the sense of minimizing an electrostatic potential free energy. Finally, numerical results are reported to show the difference between a Poisson-Fermi solution and a corresponding Poisson solution.
description: 12 pages, 3 figures
Toric Symplectic Geometry and Full Spark Frames
Creators: name: Needham, Tom
name: Shonkwiler, Clayton
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: Differential Geometry (math.DG)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: The collection of $d \times N$ complex matrices with prescribed column norms and prescribed (nonzero) singular values forms a compact algebraic variety, which we refer to as a frame space. Elements of frame spaces -- i.e., frames -- are used to give robust representations of complex-valued signals, so that geometrical and measure-theoretic properties of frame spaces are of interest to the signal processing community. This paper is concerned with the following question: what is the probability that a frame drawn uniformly at random from a given frame space has the property that any subset of $d$ of its columns gives a basis for $\mathbb{C}^d$? We show that the probability is one, generalizing recent work of Cahill, Mixon and Strawn. To prove this, we first show that frame spaces are related to highly structured objects called toric symplectic manifolds. This relationship elucidates the geometric meaning of eigensteps -- certain spectral invariants of a frame -- and should be a more broadly applicable tool for studying probabilistic questions about the structure of frame spaces. As another application of our symplectic perspective, we completely characterize the norm and spectral data for which the corresponding frame space has singularities, answering some open questions in the frame theory literature.
description: Added an example on the structure of singularities, plus other minor improvements. 30 pages
On the Calderòn problem in periodic cylindrical domain with partial Dirichlet and Neumann data
Creators: name: Choulli, Mourad
name: Kian, Yavar
name: Soccorsi, Eric
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We consider the Calderòn problem in an infinite cylindrical domain, whose cross section is a bounded domain of the plane. We prove log-log stability in the determination of the isotropic periodic conductivity coefficient from partial Dirichlet data and partial Neumann boundary observations of the solution.
Real-time, low-cost multi-person 3D pose estimation
Creators: name: Ruget, Alice
name: Tyler, Max
name: Martín, Germán Mora
name: Scholes, Stirling
name: Zhu, Feng
name: Gyongy, Istvan
name: Hearn, Brent
name: McLaughlin, Steve
name: Halimi, Abderrahim
name: Leach, Jonathan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The process of tracking human anatomy in computer vision is referred to pose estimation, and it is used in fields ranging from gaming to surveillance. Three-dimensional pose estimation traditionally requires advanced equipment, such as multiple linked intensity cameras or high-resolution time-of-flight cameras to produce depth images. However, there are applications, e.g.~consumer electronics, where significant constraints are placed on the size, power consumption, weight and cost of the usable technology. Here, we demonstrate that computational imaging methods can achieve accurate pose estimation and overcome the apparent limitations of time-of-flight sensors designed for much simpler tasks. The sensor we use is already widely integrated in consumer-grade mobile devices, and despite its low spatial resolution, only 4$\times$4 pixels, our proposed Pixels2Pose system transforms its data into accurate depth maps and 3D pose data of multiple people up to a distance of 3 m from the sensor. We are able to generate depth maps at a resolution of 32$\times$32 and 3D localization of a body parts with an error of only $\approx$10 cm at a frame rate of 7 fps. This work opens up promising real-life applications in scenarios that were previously restricted by the advanced hardware requirements and cost of time-of-flight technology.
Velocity Discretization for Lattice Boltzmann Method for Noncontinuum Bounded Gas Flows at the Micro and Nanoscale
Creators: name: Shi, Yong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The lattice Boltzmann (LB) method intrinsically links to the Boltzmann equation with the Bhatnagar-Gross-Krook collision operator; however, it has been questioned to be able to simulate noncontinuum bounded gas flows at the micro and nanoscale, where gas moves at a low speed but has a large Knudsen number. In this article, this point has been verified by simulating Couette flows at moderate and large Knudsen numbers (e.g., Kn=10 and Kn=100) by the linearized LB models based on the popular half-space Gaussian Hermite (HGH) quadrature. The underlying cause for poor accuracy of these conventional models is analyzed in light of numerical evaluation of the involved Abramowitz functions. A different thought on velocity discretization is then proposed using Gauss Legendre (LG) quadrature. Strikingly, the resulting GL-based LB models have achieved high accuracy in simulating Couette flows in the strong transition and even free molecular flow regimes. The numerical study in this article reveals an essentially different while workable way in constructing LB models for simulating micro and nanoscale low-speed gas flows with strong noncontinuum effects.
A mirrorless spinwave resonator
Creators: name: Pinel, Olivier
name: Everett, Jesse L.
name: Hosseini, Mahdi
name: Campbell, Geoff T.
name: Buchler, Ben C.
name: Lam, Ping Koy
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Optical resonance is central to a wide range of optical devices and techniques. In an optical cavity, the round-trip length and mirror reflectivity can be chosen to optimize the circulating optical power, linewidth, and free-spectral range (FSR) for a given application. In this paper we show how an atomic spinwave system, with no physical mirrors, can behave in a manner that is analogous to an optical cavity. We demonstrate this similarity by characterising the build-up and decay of the resonance in the time domain, and measuring the effective optical linewidth and FSR in the frequency domain. Our spinwave is generated in a 20 cm long Rb gas cell, yet it facilitates an effective FSR of 83 kHz, which would require a round-trip path of 3.6 km in a free-space optical cavity. Furthermore, the spinwave coupling is controllable enabling dynamic tuning of the effective cavity parameters.
description: 13 pages, 4 figures
Forming disk galaxies in wet major mergers. I. Three fiducial examples
Creators: name: Athanassoula, E.
name: Rodionov, S. A.
name: Peschken, N.
name: Lambert, J. C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Using three fiducial Nbody+SPH simulations, we follow the merging of two disk galaxies with a hot gaseous halo component each, and examine whether the merger remnant can be a spiral galaxy. The stellar progenitor disks are destroyed by violent relaxation during the merging and most of their stars form a classical bulge, while the remaining form a thick disk and its bar. A new stellar disk forms subsequently and gradually in the remnant from the gas accreted mainly from the halo. It is vertically thin and well extended in its equatorial plane. A bar starts forming before the disk is fully in place, contrary to what is assumed in idealised simulations of isolated bar-forming galaxies. It has morphological features such as ansae and boxy/peanut bulges. Stars of different ages populate different parts of the box/peanut. A disky pseudobulge forms also, so that by the end of the simulation, all three types of bulges coexist. The oldest stars are found in the classical bulge, followed by those of the thick disk, then by those in the thin disk. The youngest stars are in the spiral arms and the disky pseudobulge. The disk surface density profiles are of type II (exponential with downbending), and the circular velocity curves are flat and show that the disks are submaximum in these examples: two clearly so and one near-borderline between maximum and submaximum. On average, only roughly between 10 and 20% of the stellar mass is in the classical bulge of the final models, i.e. much less than in previous simulations.
description: 17 pages, 8 figures, accepted for publication in ApJ. V2: replaced Figure 4 with correct version
Effective Gibbs state for averaged observables
Creators: name: Teretenkov, A. E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the effective Gibbs state for averaged observables. In particular, we perturbatively calculate the correspondent effective Hamiltonian. We show that there are a lot of similarities between this effective Hamiltonian and the mean force Hamiltonian. We also discuss a thermodynamic role of the information loss due to restriction of our measurement capabilities to such averaged observables.
Ising Hamiltonians for Constrained Combinatorial Optimization Problems and the Metropolis-Hastings Warm-Starting Algorithm
Creators: name: Li, Hui-Min
name: Liang, Jin-Min
name: Wang, Zhi-Xi
name: Fei, Shao-Ming
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum approximate optimization algorithm (QAOA) is a promising variational quantum algorithm for combinatorial optimization problems. However, the implementation of QAOA is limited due to the requirement that the problems be mapped to Ising Hamiltonians and the nonconvex optimization landscapes. Although the Ising Hamiltonians for many NP hard problems have been obtained, a general method to obtain the Ising Hamiltonians for constrained combinatorial optimization problems (CCOPs) has not yet been investigated. In this paper, a general method is introduced to obtain the Ising Hamiltonians for CCOPs and the Metropolis-Hastings warm-starting algorithm for QAOA is presented which can provably converge to the global optimal solutions. The effectiveness of this method is demonstrated by tackling the minimum weight vertex cover (MWVC) problem, the minimum vertex cover (MVC) problem, and the maximal independent set problem as examples. The Ising Hamiltonian for the MWVC problem is obtained first time by using this method. The advantages of the Metropolis-Hastings warm-starting algorithm presented here is numerically analyzed through solving 30 randomly generated MVC cases with 1-depth QAOA.
Construction and analysis of Clostridium difficile response regulator mutants
Creators: name: O'Connor., Jennifer
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Simulated catalogs and maps of radio galaxies at millimeter wavelengths in Websky
Creators: name: Li, Zack
name: Puglisi, Giuseppe
name: Madhavacheril, Mathew S.
name: Alvarez, Marcelo A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present simulated millimeter-wavelength maps and catalogs of radio galaxies across the full sky that trace the nonlinear clustering and evolution of dark matter halos from the Websky simulation at $z<4.6$ and $M_{\rm halo}>10^{12} M_{\odot}/h$, and the accompanying framework for generating a new sample of radio galaxies from any halo catalog of positions, redshifts, and masses. Object fluxes are generated using a hybrid approach that combines (1) existing astrophysical halo models of radio galaxies from the literature to determine the positions and rank-ordering of the observed fluxes with (2) empirical models from the literature based on fits to the observed distribution of flux densities and (3) spectral indices drawn from an empirically-calibrated frequency-dependent distribution. The resulting population of radio galaxies is in excellent agreement with the number counts, polarization fractions, and distribution of spectral slopes from the data from observations at millimeter wavelengths from 20-200~GHz, including \emph{Planck}, ALMA, SPT, and ACT. Since the radio galaxies are correlated with the existing cosmic infrared background (CIB), Compton-$y$ (tSZ), and CMB lensing maps from Websky, our model makes new predictions for the cross-correlation power spectra and stacked profiles of radio galaxies and these other components. These simulations will be important for unbiased analysis of a wide variety of observables that are correlated with large-scale structure, such as gravitational lensing and SZ clusters.
description: For code, catalogs, and maps, see https://github.com/xzackli/WebskyRadioGalaxies
Exploring the reality of density substructures in the Palomar 5 stellar stream
Creators: name: Thomas, Guillaume F.
name: Ibata, Rodrigo
name: Famaey, Benoit
name: Martin, Nicolas F.
name: Lewis, Geraint F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present an analysis of the presence of substructures in the stellar stream of the Palomar 5 globular cluster, as derived from Sloan Digital Sky Survey data. Using a matched filter technique, we recover the positions and sizes of overdensities reported in previous studies. To explore the reality of these structures, we also create an artificial model of the stream, in which we construct a realistic background on top of which we add a perfectly smooth stream structure, taking into account the effects of photometric completeness and interstellar extinction. We find that the smooth artificial stream then shows similarly-pronounced substructures as the real structure. Interestingly, our best-fit N-body simulation does display real projected density variations linked to stellar epicyclic motions, but these become less significant when taking into account the SDSS star-count constraints. The substructures found when applying our matched filter technique to the N-body particles converted into observable stars are thus mostly unrelated to these epicyclic motions. This analysis suggests that the majority of the previously-detected substructures along the tidal tail of Palomar 5 are artefacts of observational inhomogeneities.
description: 10 pages, 9 figures, accepted for publication in MNRAS
V-FOR-WaTer - a virtual research environment for environmental research
Creators: name: Strobl, Marcus
name: Azmi, Elnaz
name: Hassler, Sibylle K.
name: Mälicke, Mirko
name: Meyer, Jörg
name: Streit, Achim
name: Zehe, Erwin
Publisher: name: Heidelberger E-Books (heiBOOKS)
Year: 2022

description: Extent and diversity of environmental data are continuously increasing due to more sensor networks with higher spatial and temporal resolution. To find appropriate data for analyses and especially for large scale models and simulations in this data explosion can take up to several months. The preprocessing of these heterogeneous datasets from different research disciplines to acquire a coherent dataset, can be done with a wide range of algorithms and tools. The outcome is a base dataset that is not reproducible and in consequence, neither are the resulting analyses [3, 9]. The datasets therefore do not obey the FAIR principles [13]. The V-FOR-WaTer web portal [11] aims to improve this situation by collecting data and metadata from a wide variety of sources and by offering preprocessed data.
Closed-form solutions of the Wheeler-DeWitt equation in a scalar-vector field cosmological model by Lie symmetries
Creators: name: Paliathanasis, Andronikos
name: Vakili, Babak
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We apply as selection rule to determine the unknown functions of a cosmological model the existence of Lie point symmetries for the Wheeler-DeWitt equation of quantum gravity. Our cosmological setting consists of a flat Friedmann-Robertson-Walker metric having the scale factor $a(t)$, a scalar field with potential function $V(ϕ)$ minimally coupled to gravity and a vector field of its kinetic energy is coupled with the scalar field by a coupling function $f(ϕ)$. Then, the Lie symmetries of this dynamical system are investigated by utilizing the behavior of the corresponding minisuperspace under the infinitesimal generator of the desired symmetries. It is shown that by applying the Lie symmetry condition the form of the coupling function and also the scalar field potential function may be explicitly determined so that we are able to solve the Wheeler-DeWitt equation. Finally, we show how we can use the Lie symmetries in order to construct conservation laws and exact solutions for the field equations.
description: 14 pages, 2 figures; to appear in Gen. Rel. Grav
Arbitrary point cloud upsampling via Dual Back-Projection Network
Creators: name: Liu, Zhi-Song
name: Wang, Zijia
name: Jia, Zhen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Point clouds acquired from 3D sensors are usually sparse and noisy. Point cloud upsampling is an approach to increase the density of the point cloud so that detailed geometric information can be restored. In this paper, we propose a Dual Back-Projection network for point cloud upsampling (DBPnet). A Dual Back-Projection is formulated in an up-down-up manner for point cloud upsampling. It not only back projects feature residues but also coordinates residues so that the network better captures the point correlations in the feature and space domains, achieving lower reconstruction errors on both uniform and non-uniform sparse point clouds. Our proposed method is also generalizable for arbitrary upsampling tasks (e.g. 4x, 5.5x). Experimental results show that the proposed method achieves the lowest point set matching losses with respect to the benchmark. In addition, the success of our approach demonstrates that generative networks are not necessarily needed for non-uniform point clouds.
description: 5 pages, 5 figures
Small-world complex network generation on a digital quantum processor
Creators: name: Jones, Eric B.
name: Hillberry, Logan E.
name: Jones, Matthew T.
name: Fasihi, Mina
name: Roushan, Pedram
name: Jiang, Zhang
name: Ho, Alan
name: Neill, Charles
name: Ostby, Eric
name: Graf, Peter
name: Kapit, Eliot
name: Carr, Lincoln D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum cellular automata (QCA) evolve qubits in a quantum circuit depending only on the states of their neighborhoods and model how rich physical complexity can emerge from a simple set of underlying dynamical rules. For instance, Goldilocks QCA depending on trade-off principles exhibit non-equilibrating coherent dynamics and generate complex mutual information networks, much like the brain. The inability of classical computers to simulate large quantum systems is a hindrance to understanding the physics of quantum cellular automata, but quantum computers offer an ideal simulation platform. Here we demonstrate the first experimental realization of QCA on a digital quantum processor, simulating a one-dimensional Goldilocks rule on chains of up to 23 superconducting qubits. Employing low-overhead calibration and error mitigation techniques, we calculate population dynamics and complex network measures indicating the formation of small-world mutual information networks. Unlike random states, these networks decohere at fixed circuit depth independent of system size; the largest of which corresponds to 1,056 two-qubit gates. Such computations may open the door to the employment of QCA in applications like the simulation of strongly-correlated matter or beyond-classical computational demonstrations.
Steel: the work of bodies
Creators: name: RICHARDSON, AUGUSTA VINALL
Publisher: name: Monash University
Year: 2023
Subjects: Art history
Art history, theory and criticism not elsewhere classified

description: The thesis investigates the use of steel as an art making materials in service of producing three-dimensional forms. Through the process of learning how to weld, to work with metal in an industrial workshop environment, the artist uncovers possible connections and relationships that manifest through this sustained engagement with steel. Within the writing the artist concurrently explores the practice of two Australian artists, Inge King and Rose Nolan, which assists her in analysing material practice, and own her desires, impulses and modes of working.
Magnon-driven dynamics of frustrated skyrmion in synthetic antiferromagnets: Effect of skyrmion precession
Creators: name: Jin, Z.
name: Hu, Y. F.
name: Liu, T. T.
name: Liu, Y.
name: Hou, Z. P.
name: Chen, D. Y.
name: Fan, Z.
name: Zeng, M.
name: Lu, X. B.
name: Gao, X. S.
name: Qin, M. H.
name: Liu, J. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: A theoretical study on the interplay of frustrated skyrmion and magnons is useful for revealing new physics and future experiments design. In this work, we investigated the magnon-driven dynamics of frustrated skyrmion in synthetic antiferromagnets, focusing on the effect of skyrmion precession. It is theoretically revealed that the scattering cross section of the injected magnons depends on the skyrmion precession, which in turn effectively modulates the skyrmion Hall motion. Specifically, the Hall angle decreases as the precession speed increases, which is also verified by the atomistic micromagnetic simulations. Moreover, the precession speed and the Hall angle of the frustrated skyrmion depending on the magnon intensity and damping constant are simulated, demonstrating the effective suppression of the Hall motion by the skyrmion precession. This work provides a comprehensive understanding of the magnon-skyrmion scattering in frustrated magnets, benefiting future spintronic and magnonic applications.
description: 18 pages, 5 figures
Renal medullary oxygenation and antihypertensive mechanisms
Creators: name: O'Connor., Paul Michael
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Emission from hadronic and leptonic processes in galactic jet-driven bubbles
Creators: name: Owen, Ellis R.
name: Yang, H. -Y. Karen
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the multiwavelength emission from hadronic and leptonic cosmic rays (CRs) in bubbles around galaxies, analogous to the Fermi bubbles of the Milky Way. The bubbles are modeled using 3D magnetohydrodynamical (MHD) simulations, and are driven by a 0.3 Myr intense explosive outburst from the nucleus of Milky Way-like galaxies. We compute their non-thermal emission properties at different stages throughout their evolution, up to 7 Myr, by post-processing the simulations. We compare the spectral and spatial signatures of bubbles with hadronic, leptonic and hybrid hadro-leptonic CR compositions. These each show broadly similar emission spectra, comprised of radio synchrotron, inverse Compton and non-thermal bremsstrahlung components. However, hadronic and hybrid bubbles were found to be brighter than leptonic bubbles in X-rays, and marginally less bright at radio frequencies, and in $γ$-rays between $\sim$ 0.1 and a few 10s of GeV, with a large part of their emission being driven by secondary electrons formed in hadronic interactions. Hadronic systems were also found to be slightly brighter in high-energy $γ$-rays than their leptonic counterparts, owing to the $π^0$ decay emission that dominates their emission between energies of 100s of GeV and a few TeV.
description: 18 pages, 7 figures, 2 tables. Accepted for publication in MNRAS
Fluid dynamics in porous media with Sailfish
Creators: name: Coelho, Rodrigo C. V.
name: Neumann, Rodrigo F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In this work we show the application of Sailfish to the study of fluid dynamics in porous media. Sailfish is an open-source software based on the lattice-Boltzmann method. This application of computational fluid dynamics is of particular interest to the oil and gas industry and the subject could be a starting point for an undergraduate or graduate student in physics or engineering. We built artificial samples of porous media with different porosities and used Sailfish to simulate the fluid flow through in order to calculate permeability and tortuosity. We also present a simple way to obtain the specific superficial area of porous media using Python libraries. To contextualize these concepts, we test the Kozeny--Carman equation, discuss its validity and calculate the Kozeny's constant for our artificial samples.
description: 13 pages, 12 figures
Visibility Properties of Spiral Sets
Creators: name: Adiceam, Faustin
name: Tsokanos, Ioannis
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: A spiral in $\mathbb{R}^{d+1}$ is defined as a set of the form $\left\{\sqrt[d+1]{n}\cdot\boldsymbol{u}_n\right\}_{n\ge 1},$ where $\left(\boldsymbol{u}_n\right)_{n\ge 1}$ is a spherical sequence. Such point sets have been extensively studied, in particular in the planar case $d=1$, as they then serve as natural models describing phyllotactic structures (i.e. structures representing configurations of leaves on a plant stem). Recent progress in this theory provides a fine analysis of the distribution of spirals (e.g., their covering and packing radii). Here, various concepts of visiblity from discrete geometry are employed to characterise density properties of such point sets. More precisely, necessary an sufficient conditions are established for a spiral to be (1) an orchard (a "homogeneous" density property defined by Pòlya), (2) a uniform orchard (a concept introduced in this work), (3) a set with no visible point (implying that the point set is dense enough in a suitable sense) and (4) a dense forest (a quantitative and uniform refinement of the previous concept).
description: Updated with comments from the referee
Soft-IntroVAE for Continuous Latent space Image Super-Resolution
Creators: name: Liu, Zhi-Song
name: Wang, Zijia
name: Jia, Zhen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Continuous image super-resolution (SR) recently receives a lot of attention from researchers, for its practical and flexible image scaling for various displays. Local implicit image representation is one of the methods that can map the coordinates and 2D features for latent space interpolation. Inspired by Variational AutoEncoder, we propose a Soft-introVAE for continuous latent space image super-resolution (SVAE-SR). A novel latent space adversarial training is achieved for photo-realistic image restoration. To further improve the quality, a positional encoding scheme is used to extend the original pixel coordinates by aggregating frequency information over the pixel areas. We show the effectiveness of the proposed SVAE-SR through quantitative and qualitative comparisons, and further, illustrate its generalization in denoising and real-image super-resolution.
description: 5 pages, 4 figures
Conformational antigenic epitopes revealed by phage dispalyed peptide libraries
Creators: name: O'Connor., Karen
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
The philosophical and empirical intersections of Chinese medicine and western medicine
Creators: name: O'Brien., Kylie Ann
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Band tilt induced nonlinear Nernst effect in topological insulators: An efficient generation of high-performance spin polarization
Creators: name: Zeng, Chuanchang
name: Yu, Xiao-Qin
name: Yu, Zhi-Ming
name: Yao, Yugui
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Topological insulators (TIs) hold promise as a platform for spintronics applications due to the fascinating spin-momentum locking (SML) of the surface states. One particular interest lies in using TIs as spin-polarized sources for spintronics structures. Here, we propose the band tilt induced nonlinear Nernst effect (NLNE) in TIs as a clean and efficient route to generate high-performance spin polarization (SP). We show that in the presence of SML and hexagonal warping effect a finite band tilt can induce an imbalance of two spin carriers and effectively give rise to spin-polarized NLNE current in TIs. In our scheme, both the spin current and charge current regime can be achieved under the thermal drive. The obtainable SP can be efficiently tuned in either a smooth or rapid way, exhibiting highly flexible tunability. In addition, near-unity SP can be generated within a wide range of tunable parameters, which is also found to be robust against temperature. Therefore, our work provides a mechanism to realize controllable room-temperature high-degree SP based on TIs, which is of essential importance for future spintronics applications.
description: The accepted version in PRB Letter
Methionine in Poultry Nutrition: A Review
Creators: name: Publication, Rovedar
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 300303
subject: Animal nutrition

description: AbstractMethionine is an essential amino acid which is commonly used as a supplement in poultry diets. Multiple systems are involved in the absorption and transportation of liquid and powder Methionine in the segment of the jejunum. Methionine supplementation in a low-protein diet alleviates the negative effects of heat stress and improves the performance of chickens. The supplementation of the synthetic Methionine improves the amino acid balance and consequently promotes growth performance by enhancing quantity and quality of egg production, feed efficiency, and protein synthesis, as well as decreasing fat synthesis in poultry breeds (Broiler Chicken, Laying hen, Turkey, Duck, Guinea fowl, Quail breeder, and Gees). Methionine supplementation also improves the immune response through the direct effects on protein synthesis and breakdown and indirect effects on the derivatives of Methionine. The variables, such as growing period, type of production, sex, and breed, influence the Methionine requirement. Moreover, the Methionine requirement expressed as a percentage of diet declines during the starter and grower phases.https://jwps.rovedar.com/index.php/JWPS/article/view/1
Space-time wave packets localized in all dimensions
Creators: name: Yessenov, Murat
name: Free, Justin
name: Chen, Zhaozhong
name: Johnson, Eric G.
name: Lavery, Martin P. J.
name: Alonso, Miguel A.
name: Abouraddy, Ayman F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Optical wave packets that are localized in space and time, but nevertheless overcome diffraction and travel rigidly in free space, are a long sought-after field structure with applications ranging from microscopy and remote sensing, to nonlinear and quantum optics. However, synthesizing such wave packets requires introducing non-differentiable angular dispersion with high spectral precision in two transverse dimensions, a capability that has eluded optics to date. Here, we describe an experimental strategy capable of sculpting the spatio-temporal spectrum of a generic pulsed beam by introducing arbitrary radial chirp via two-dimensional conformal coordinate transformations of the spectrally resolved field. This procedure yields propagation-invariant `space-time' wave packets localized in all dimensions, with tunable group velocity in the range from $0.7c$ to $1.8c$ in free space, and endowed with prescribed orbital angular momentum. By providing unprecedented flexibility in sculpting the three-dimensional structure of pulsed optical fields, our experimental strategy promises to be a versatile platform for the emerging enterprise of space-time optics.
description: 12 pages of Main text with 7 figures. 37 pages of Supplementary document with 18 figures
Disorder- and Topology-Enhanced Fully Spin-Polarized Currents in Nodal Chain Spin-Gapless Semimetals
Creators: name: Zhou, Xiaodong
name: Zhang, Run-Wu
name: Yang, Xiuxian
name: Li, Xiao-Ping
name: Feng, Wanxiang
name: Mokrousov, Yuriy
name: Yao, Yugui
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Recently discovered high-quality nodal chain spin-gapless semimetals $M$F$_3$ ($M$ = Pd, Mn) feature an ultra-clean nodal chain in the spin up channel residing right at the Fermi level and displaying a large spin gap leading to a 100\% spin-polarization of transport properties. Here, we investigate both intrinsic and extrinsic contributions to anomalous and spin transport in this class of materials. The dominant intrinsic origin is found to originate entirely from the gapped nodal chains without the entanglement of any other trivial bands. The side-jump mechanism is predicted to be negligibly small, but intrinsic skew-scattering enhances the intrinsic Hall and Nernst signals significantly, leading to large values of respective conductivities. Our findings open a new material platform for exploring strong anomalous and spin transport properties in magnetic topological semimetals.
description: 7 pages, 4 figures
Ecological genetics of three enzyme polymorphisms of drosophila melanogaster : ADH, [alpha]-GPDH and TPI
Creators: name: Nielsen., Karen M.
Publisher: name: Monash University
Year: 2021

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