cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
An analytical model of iceberg drift
Creators: name: Wagner, Till J. W.
name: Dell, Rebecca W.
name: Eisenman, Ian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Iceberg drift and decay and the associated freshwater release are increasingly seen as important processes in Earth's climate system, yet a detailed understanding of their dynamics has remained elusive. Here, an idealized model of iceberg drift is presented. The model is designed to include the most salient physical processes that determine iceberg motion while remaining sufficiently simple to facilitate physical insight into iceberg drift dynamics. We derive an analytical solution of the model, which helps build understanding and also enables the rapid computation of large numbers of iceberg trajectories. The long-standing empirical rule of thumb that icebergs drift at 2% of the wind velocity, relative to the ocean current, is derived here from physical first principles, and it is shown that this relation only holds in the limit of strong winds or small icebergs, which approximately applies for typical icebergs in the Arctic. It is demonstrated that the opposite limit of weak winds or large icebergs approximately applies for typical Antarctic tabular icebergs, and that in this case the icebergs simply move with the ocean surface current. It is furthermore found that when winds are strong, wind drag drives icebergs in the direction the wind blows, whereas weak winds drive icebergs at a 90 degree angle to the wind direction.
description: 10 pages, 7 figures
Restricted phase space thermodynamics of charged AdS black holes in conformal gravity
Creators: name: Kong, Xiangqing
name: Zhang, Zhiqiang
name: Zhao, Liu
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The thermodynamics of charged spherically symmetric AdS black holes in conformal gravity is revisited using the recently proposed restricted phase space (RPS) formalism. This formalism avoids all the bizarreness that arose in the extended phase space formalism for this model. It is found that the charged AdS black holes in this model may belong to a new universality class which is different from all previously studied cases under the RPS formalism. Besides the distinguished isocharge $T-S$ and isothermal $Φ-Q_e$ behaviors, the absence of Hawking-Page transition is another notable feature. On the other hand, in the high temperature limit, the thermodynamic behavior of the present model become exactly the same as that of the Einstein gravity and the black hole scan models, which add further evidence for the universality of the recently reported correspondence between high temperature AdS black holes and low temperature quantum phonon gases in nonmetallic crystals.
description: 22 pages, 11 pdf figures
Sir George Newman and his role as an educator
Creators: name: Smith, Heather Kathryn
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 Reference field.
Faster variational quantum algorithms with quantum kernel-based surrogate models
Creators: name: Smith, Alistair W. R.
name: Paige, A. J.
name: Kim, M. S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We present a new optimization method for small-to-intermediate scale variational algorithms on noisy near-term quantum processors which uses a Gaussian process surrogate model equipped with a classically-evaluated quantum kernel. Variational algorithms are typically optimized using gradient-based approaches however these are difficult to implement on current noisy devices, requiring large numbers of objective function evaluations. Our scheme shifts this computational burden onto the classical optimizer component of these hybrid algorithms, greatly reducing the number of queries to the quantum processor. We focus on the variational quantum eigensolver (VQE) algorithm and demonstrate numerically that such surrogate models are particularly well suited to the algorithm's objective function. Next, we apply these models to both noiseless and noisy VQE simulations and show that they exhibit better performance than widely-used classical kernels in terms of final accuracy and convergence speed. Compared to the typically-used stochastic gradient-descent approach for VQAs, our quantum kernel-based approach is found to consistently achieve significantly higher accuracy while requiring less than an order of magnitude fewer quantum circuit evaluations. We analyse the performance of the quantum kernel-based models in terms of the kernels' induced feature spaces and explicitly construct their feature maps. Finally, we describe a scheme for approximating the best-performing quantum kernel using a classically-efficient tensor network representation of its input state and so provide a pathway for scaling these methods to larger systems.
Vector quarkonia at the LHC with JETHAD: A high-energy viewpoint
Creators: name: Celiberto, Francesco Giovanni
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In this review we discuss and extend the study of the inclusive production of vector quarkonia, $J/ψ$ and $Υ$, emitted with large transverse momenta and rapidities at the LHC. We adopt the novel ZCW19$^+$ determination to depict the quarkonium production mechanism at the next-to-leading level of perturbative QCD. This approach is based on the nonrelativistic QCD formalism well adapted to describe the production of a quarkonium state from the collinear fragmentation of a gluon or a constituent heavy quark at the lowest energy scale. We rely upon the NLL/NLO$^+$ hybrid high-energy and collinear factorization for differential cross sections, where the standard collinear formalism is enhanced by the BFKL resummation of next-to-leading energy logarithms arising in the $t$-channel. We employ the JETHAD method to analyze the behavior of rapidity distributions for double inclusive vector-quarkonium and inclusive vector-quarkonium plus jet emissions. We discovered that the natural stability of the high-energy series, previously observed in observables sensitive to the emission of hadrons with heavy flavor detected in the rapidity acceptance of LHC barrel calorimeters, becomes even more manifest when these particles are tagged in forward regions covered by endcaps. Our findings brace the important message that vector quarkonia at the LHC via the hybrid factorization offer a unique chance to perform precision studies of high-energy QCD, as well as an intriguing opportunity to shed light on the quarkonium production puzzle.
description: 42 pages, 8 figures, 526 references. Invited review article
A Dynamic Observer for a Class of Infinite-Dimensional Vibrating Flexible Structures
Creators: name: Zuyev, Alexander
name: Kalosha, Julia
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 93B53, 93D20, 74K10

description: Infinite-dimensional control systems with outputs are considered in the Hamiltonian formulation with generalized coordinates. An explicit scheme for constructing a dynamic observer for this class of systems is proposed with arbitrary gain coefficients. Sufficient conditions for the convergence of the constructed observer are obtained on the basis of the invariance principle. This result is applied to a flexible beam model attached to a mass-spring system with lumped and distributed actuators. The estimation error decay is illustrated with numerical simulations of finite-dimensional approximations of the observer dynamics.
description: This is a preprint version of the paper accepted to the 2023 European Control Conference
From immunity to sudden death: Effects of strong disorder in strongly correlated superconductors
Creators: name: Chakraborty, Debmalya
name: Sensarma, Rajdeep
name: Ghosal, Amit
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the effect of strong disorder on a system with strong electronic repulsion. In absence of disorder, the system has a d-wave superconducting ground-state with strong non-BCS features due to its proximity to a Mott insulator. We find that, while strong correlations make superconductivity in this system immune to weak disorder, superconductivity is destroyed efficiently when disorder strength is comparable to the effective bandwidth. The suppression of charge motion in regions of strong potential fluctuation leads to formation of Mott insulating patches, which anchor a larger non-superconducting region around them. The system thus breaks into islands of Mott insulating and superconducting regions, with Anderson insulating regions occurring along the boundary of these regions. Thus, electronic correlation and disorder, when both are strong, aid each other in destroying superconductivity, in contrast to their competition at weak disorder. Our results shed light on why Zinc impurities are efficient in destroying superconductivity in cuprates, even though it is robust to weaker impurities.
description: 5 pages, 3 figures + Supplementary Material
J = 0 nonmagnetic insulating state in K$_2$Os$X_6$ (X = F, Cl and Br)
Creators: name: Zhang, Yang
name: Lin, Ling-Fang
name: Moreo, Adriana
name: Dagotto, Elbio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In $4d/5d$ transition-metal systems, many interesting physical properties arise from the interplay of bandwidth, electronic correlations, and spin-orbit interactions. Here, using {\it ab initio} density functional theory, we systematically study the double-perovskite-like system K$_2$Os$X_6$ (X = F, Cl, and Br) with a $5d^4$ electronic configuration. Our main result is that the $J = 0$ nonmagnetic insulating state develops in this system, induced by strong spin-orbital coupling. Specifically, the well-separated Os$X_6$ octahedra lead to the cubic crystal-field limit and result in dramatically decreasing hoppings in nearest neighbor Os-Os sites. In this case, the three degenerate $t_{2g}$ orbitals are reconstructed into two ``effective'' $j_{\rm eff}$ ($j_{\rm eff} = 1/2$ and $j_{\rm eff} = 3/2$ states) states separated by the strong SOC, opening a gap with four electrons occupying the $j_{\rm eff} = 3/2$ orbitals. Furthermore, the hybridization between the Os $5d$ orbitals and the $X$ ($X$ = F, Cl, and Br) $p$ orbitals increases from F to Br, leading the electrons in K$_2$OsF$_6$ to be more localized than in K$_2$OsCl$_6$ and K$_2$OsBr$_6$, resulting in a smaller bandwidth for K$_2$OsF$_6$ than in the Cl- or Br- cases. Our results provide guidance to experimentalists and theorists working on this interesting family of osmium halides.
The ZX-calculus as a Language for Topological Quantum Computation
Creators: name: Ahmadi, Fatimah Rita
name: Kissinger, Aleks
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Category Theory (math.CT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Unitary fusion categories formalise the algebraic theory of topological quantum computation. These categories come naturally enriched in a subcategory of the category of Hilbert spaces, and by looking at this subcategory, one can identify a collection of generators for implementing quantum computation. We represent such generators for the Fibonacci and Ising models, namely the encoding of qubits and the associated braid group representations, with the ZX-calculus and show that in both cases, the Yang-Baxter equation is directly connected to an important rule in the complete ZX-calculus known as the P-rule, which enables one to interchange the phase gates defined with respect to complementary bases. In the Ising case, this reduces to a familiar rule relating two distinct Euler decompositions of the Hadamard gate as $π/2$ Z- and X-phase gates, whereas in the Fibonacci case, we give a previously unconsidered exact solution of the P-rule involving the Golden ratio. We demonstrate the utility of these representations by giving graphical derivations of the single-qubit braid equations for Fibonacci anyons and the single- and two-qubit braid equations for Ising anyons. We furthermore present a fully graphical procedure for simulating and simplifying braids with the ZX-representation of Fibonacci anyons.
Imperial validity and maritime education in Australia, 1869-1923 : a study of the influence of the imperial statutory qualifications on the education of the Australian merchant service officer, 1869-1923
Creators: name: Shorten, Ann R.
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 Reference field.
Ultra-bright GeV photon source via controlled electromagnetic cascades in laser-dipole waves
Creators: name: Gonoskov, A.
name: Bashinov, A.
name: Bastrakov, S.
name: Efimenko, E.
name: Ilderton, A.
name: Kim, A.
name: Marklund, M.
name: Meyerov, I.
name: Muraviev, A.
name: Sergeev, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: One aim of upcoming high-intensity laser facilities is to provide new high-flux gamma-ray sources. Electromagnetic cascades may serve for this, but are known to limit both field strengths and particle energies, restricting efficient production of photons to sub-GeV energies. Here we show how to create a directed GeV photon source, enabled by a controlled interplay between the cascade and anomalous radiative trapping. Using advanced 3D QED particle-in-cell (PIC) simulations and analytic estimates, we show that the concept is feasible for planned peak powers of 10 PW level. A higher peak power of 40 PW can provide $10^9$ photons with GeV energies in a well-collimated 3 fs beam, achieving peak brilliance ${9 \times 10^{24}}$ ph s$^{-1}$mrad$^{-2}$mm$^{-2}$/0.1${\%}$BW. Such a source would be a powerful tool for studying fundamental electromagnetic and nuclear processes.
Patch-level Routing in Mixture-of-Experts is Provably Sample-efficient for Convolutional Neural Networks
Creators: name: Chowdhury, Mohammed Nowaz Rabbani
name: Zhang, Shuai
name: Wang, Meng
name: Liu, Sijia
name: Chen, Pin-Yu
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In deep learning, mixture-of-experts (MoE) activates one or few experts (sub-networks) on a per-sample or per-token basis, resulting in significant computation reduction. The recently proposed \underline{p}atch-level routing in \underline{MoE} (pMoE) divides each input into $n$ patches (or tokens) and sends $l$ patches ($l\ll n$) to each expert through prioritized routing. pMoE has demonstrated great empirical success in reducing training and inference costs while maintaining test accuracy. However, the theoretical explanation of pMoE and the general MoE remains elusive. Focusing on a supervised classification task using a mixture of two-layer convolutional neural networks (CNNs), we show for the first time that pMoE provably reduces the required number of training samples to achieve desirable generalization (referred to as the sample complexity) by a factor in the polynomial order of $n/l$, and outperforms its single-expert counterpart of the same or even larger capacity. The advantage results from the discriminative routing property, which is justified in both theory and practice that pMoE routers can filter label-irrelevant patches and route similar class-discriminative patches to the same expert. Our experimental results on MNIST, CIFAR-10, and CelebA support our theoretical findings on pMoE's generalization and show that pMoE can avoid learning spurious correlations.
Understanding looping kinetics of a long polymer molecule in solution. Exact solution for delta function sink model
Creators: name: Ganguly, Moumita
name: Chakraborty, Anirudhha
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: A diffusion theory for intramolecular reactions of polymer chain in dilute solution is formulated. We give a detailed analytical expression for calculation of rate of polymer looping in solution. The physical problem of looping can be modeled mathematically with the use of a Smoluchowski like equation with a Dirac delta function sink of finite strength. The solution of this equation is expressed in terms of Laplace Transform of the Greens function for end to end motion of the polymer in absence of the sink. We have defined two different rate constants, the long term rate constant and the short term rate constant. The short term rate constant and long term rate constant varies with several parameters such as length of the polymer, bond length and the relaxation time. The long term rate constant is independent of the initial probability distribution.
Momentum flux fluctuations in wall turbulence formulated along the distance from the wall
Creators: name: Mouri, H.
name: Ito, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Wall turbulence has a sublayer where the mean wall-normal flux of the streamwise momentum is constant. Via the law of the wall, this mean flux is related to the wall-normal profile of the mean streamwise velocity. However, the momentum flux has large fluctuations, for which the corresponding law is yet unknown. To formulate such a law, we decompose fluctuations of the streamwise and the wall-normal velocities. These are smoothed to single out a component that would dominate the momentum flux fluctuations. It is dependent on the wall-normal distance. We relate this dependence to the wall-normal profile of the streamwise velocity variance. The resultant law is consistent with laboratory and field data across a wide range of that distance and applies readily to wall modeling of a numerical simulation.
description: 10 pages, to appear in Physics of Fluids (see https://pubs.aip.org/aip/pof )
Development of long-range phase coherence on the Kondo lattice
Creators: name: Dong, Jian-Jun
name: Yang, Yi-feng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Despite of many efforts, we still lack a clear picture on how heavy electrons emerge and develop on the Kondo lattice. Here we introduce a key concept named the hybridization bond phase and propose a scenario based on phase correlation to address this issue. The bond phase is a gauge-invariant quantity combining two onsite hybridization fields mediated by inter-site magnetic correlations. Its probabilistic distribution decays exponentially with site distance, from which a characteristic length scale can be extracted to describe the spatial correlation of Kondo hybridizations. Our calculations show that this correlation length grows logarithmically with lowering temperature at large Kondo coupling, and reveal a precursor pseudogap state with short-range phase correlation before long-range phase coherence is developed to form the Kondo insulating (or heavy electron) state at low temperatures. This provides a potential microscopic explanation of the two-stage hybridization proposed by recent pump-probe experiment and the logarithmic scaling in the phenomenological two-fluid model. Our work offers a novel theoretical framework to describe the phase-related physics in Kondo lattice systems.
description: 9 pages, 5 figures
BY-COVID D8.2.2 Project Data Management Plan initial release and periodic updates M15
Creators: name: Garcia Alvarez, Eva
name: Holub, Petr
Publisher: name: Zenodo
Year: 2022
Subjects: Data Management Plan
BY-COVID
DMP
FAIR

description: The Data Management Plan (hereinafter “the project DMP”) is a mandatory deliverable by the European Commission (EC) that has to be tailored to the specific project activities and which should document the relevant project repositories and how they are managed. The Data Management Plan for BY-COVID is developed by WP8 as an integral part of the governance structure, and also oversees the quality assurance of the project outcomes. BY-COVID will not generate new sensitive patient level data but integrate and link existing resources. Hence, responsibility remains on data access committees and processes for each dataset. The project DMP considers: Overview of the project data flow Compliance with Open Science and FAIR data sharing Ethics Requirements1 as required according to the Grant Agreement (WP9) This document is BY-COVID Data Management Plan (DMP) version 0.2 delivered in month 15, being an update of the first version delivered in month 06. This deliverable is based on the template and the guidelines provided by the European Commission for Horizon Europe. Of note, the project DMP is a live document that will be reviewed and updated periodically to ensure it remains up to date.
Teacher cognition among tertiary-level Chinese English teachers
Creators: name: Kavanagh, Michael Christopher
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: Teacher cognition studies are rare in the mainland Chinese context; they are also rare in other contexts similarly defined by common features such as non-native speaking language teachers, large classes, publicly-funded institutions, and mandated curricula or materials. This broadly qualitative investigation of three tertiary-level Chinese English teachers sought to elicit views and beliefs about language learning and teaching, their sources, and their links with classroom behaviour. A cyclical series of data collection (including autobiographical writing, interviews, lesson observations and stimulated-recall interviews, documentary data, and a group discussion) was employed to produce four linked studies: three individual case studies and a cross-case study. Interpretive data analysis, achieved through a process of constant comparison, was employed to reveal each teacher's views and beliefs. In order to ensure an emic perspective, each teacher's 'voice' is given prominence through the presentation of data. The interpretation of data suggests the importance of various levels of context to teachers' thinking, including the background Confucian approach to education, previous experiences as learners and teachers, and the situation the teachers encounter at both classroom and institutional levels.
A proposal of the gauge theory description of the small Schwarzschild black hole in AdS$_5\times$S$^5$
Creators: name: Hanada, Masanori
name: Maltz, Jonathan
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Based on 4d ${\cal N}=4$ SYM on $\mathbb{R}^{1}\times$S$^3$, a gauge theory description of a small black hole in AdS$_5\times$S$^5$ is proposed. The change of the number of dynamical degrees of freedom associated with the emission of the scalar fields' eigenvalues plays a crucial role in this description. By analyzing the microcanonical ensemble, the Hagedorn behavior of long strings at low energy is obtained. Modulo an assumption based on the AdS/CFT duality for a large black hole, the energy of the small ten-dimensional Schwarzschild black hole $E\sim 1/(G_{\rm 10,N}T^7)$ is derived. A heuristic gauge theory argument supporting this assumption is also given. The same argument applied to the ABJM theory correctly reproduces the relation for the eleven-dimensional Schwarzschild black hole. One of the consequences of our proposal is that the small and large black holes are very similar when seen from the gauge theory point of view.
description: 16 pages, 8 figures. A few corrections in equations and logic have been added to section 3. The result remains unchanged
Detecting deviations from Gaussianity in high-redshift CMB lensing maps
Creators: name: Zhang, Zhuoqi
name: Omori, Yuuki
name: Chang, Chihway
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: While the probability density function (PDF) of the cosmic microwave background (CMB) convergence field approximately follows a Gaussian distribution, primordial non-Gaussianities and small contributions from structures at low redshifts make the overall distribution slightly non-Gaussian. Some of the late-time component can be modelled using the distribution of galaxies and subtracted off from the original CMB lensing map to produce a map of matter distribution at high redshifts. Using this high-redshift mass map, we are able to directly study the early phases of structure formation. In this work, we forecast the detectability of signatures of non-Gaussianity due to nonlinear structure formation at $z>1.2$. Assuming the optimal case of no systematics, we find that it is challenging to detect such signatures in current surveys, but future experiments such as the deep field of CMB-S4 will be able to make detections of $\sim7σ$.
description: 10 pages, 9+3 figures. Comments welcome
Improved model of primordial black hole formation after Starobinsky inflation
Creators: name: Saburov, Sultan
name: Ketov, Sergei V.
Publisher: name: arXiv
Year: 2023
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: FOS: Physical sciences

description: A new (improved) model of inflation and primordial black hole (PBH) formation is proposed by combining Starobinsky model of inflation, Appleby-Battye-Starobinsky (ABS) model of dark energy and a quantum correction in the modified $F(R)$ gravity. The energy scale parameter in the ABS model is taken to be close to the inflationary scale, in order to describe double inflation instead of dark energy. The quantum correction is given by the term quartic in the spacetime scalar curvature $R$ with a negative coefficient $(-δ)$ in the $F(R)$ function. It is demonstrated that very good agreement (within $1σ$) with current measurements of the cosmic microwave background (CMB) radiation can be achieved by choosing the proper value of $δ$, thus solving the problem of low values of the tilt of CMB scalar perturbations in the earlier proposed model in arXiv:2205.00603. A large (by the factor of $10^7$ against CMB) enhancement in the power spectrum of scalar perturbations is achieved by fine-tuning the parameters of the model. It is found by numerical analysis that it can lead to formation of asteroid-size PBH with the masses up to $10^{20}$ g, which may form dark matter in the current universe.
description: 12 pages, 6 figures, LaTeX; minor corrections
A study of Brunei education in relation to policy and ideology
Creators: name: Abu Bakar Bin Pg Sarifuddin, Pg
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 Reference field.
Sonic Landau-level lasing and synthetic gauge fields in mechanical metamaterials
Creators: name: Abbaszadeh, Hamed
name: Souslov, Anton
name: Paulose, Jayson
name: Schomerus, Henning
name: Vitelli, Vincenzo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Mechanical strain can lead to a synthetic gauge field that controls the dynamics of electrons in graphene sheets as well as light in photonic crystals. Here, we show how to engineer an analogous synthetic gauge field for lattice vibrations. Our approach relies on one of two strategies: shearing a honeycomb lattice of masses and springs or patterning its local material stiffness. As a result, vibrational spectra with discrete Landau levels are generated. Upon tuning the strength of the gauge field, we can control the density of states and transverse spatial confinement of sound in the metamaterial. We also use the gauge field to design waveguides in which sound propagates robustly, as a consequence of the change in topological polarization that occurs along a domain wall in the bulk of the metamaterial. By introducing dissipation, we can selectively enhance the domain-wall-bound topological sound mode, a feature that may be exploited for the design of sound amplification by stimulated emission of radiation - SASERs, the mechanical analogs of lasers.
The Advent of Methodism and the I Taukei: The Methodist Church In Fijian Nation-making
Creators: name: Williams, Beverley
Publisher: name: La Trobe
Year: 2023

description: Abstract: This thesis is an historical anthropology of the role of the Methodist Church in Fiji, from the arrival of Methodist missionaries in 1830. At that time Fiji was a fragmented society. Fijians lived in villages on various islands, so there was no cohesion within the society. The insertion of Methodism into traditional Fijian society irreversibly changed the society, and this thesis traces the key changes that occurred. The rise to prominence of Chief Cakobau from Bau Island marks the beginning of unification of a fragmented Fiji. He formed the first Fijian government in 1871.The British Colonial authorities and the Methodists were also centrally involved in unification and the development of a national society as they set up structures to govern and evangelise the Fijians. However, the thesis argues that with the arrival of Indo-Fijians as indentured labourers to Fiji in 1879, the seeds of polarisation were planted and Indo- Fijians were left out of the frame of Fijian society. The thesis traces the involvement of Methodism, always in close relationship with the state in the twin processes of unification and polarisation. The coups that have changed the political landscape of Fiji served to alter the relationship between the Methodist Church and the state. A schism occurred in the Methodist Church following the 1987 coup, where violence against some ministers occurred, and the Methodist constitution was suspended. Members belonging to i taukei Methodist hierarchy who insisted on Fijian paramountcy to the exclusion of Indo-Fijians have been separated irretrievably from members of the Methodist hierarchy who believe in an inclusive society irrespective of race. Increasing diversity of socio-economic status allied with hierarchical divides and different interpretations of the Church’s mission have generated conflict in the Church and society at large. Diminution of the power of the Methodist Church in Fiji has occurred since 1987, and there are both internal and external factors at work which continue this trend. The various factors influencing the Church in the present along with its future prospects are discussed.

This thesis contained third party copyright material which has been removed.

Originally part of the Australasian Digital Theses (ADT) database.
Epistemic and Aleatoric Uncertainty Quantification and Surrogate Modelling in High-Performance Multiscale Plasma Physics Simulations
Creators: name: Yudin, Yehor
name: Coster, David
name: von Toussaint, Udo
name: Jenko, Frank
Publisher: name: arXiv
Year: 2023
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: G.1.0; G.4.0

description: This work suggests several methods of uncertainty treatment in multiscale modelling and describes their application to a system of coupled turbulent transport simulations of a tokamak plasma. We propose a method to quantify the usually aleatoric uncertainty of a system in a quasi-stationary state, estimating the mean values and their errors for quantities of interest, which is average heat fluxes in the case of turbulence simulations. The method defines the stationarity of the system and suggests a way to balance the computational cost of simulation and the accuracy of estimation. This allows, contrary to many approaches, to incorporate aleatoric uncertainties in the analysis of the model and to have a quantifiable decision for simulation runtime. Furthermore, the paper describes methods for quantifying the epistemic uncertainty of a model and the results of such a procedure for turbulence simulations, identifying the model's sensitivity to particular input parameters and sensitivity to uncertainties in total. Finally, we introduce a surrogate model approach based on Gaussian Process Regression and present a preliminary result of training and analysing the performance of such a model based on turbulence simulation data. Such an approach shows a potential to significantly decrease the computational cost of the uncertainty propagation for the given model, making it feasible on current HPC systems.
Anisotropic magnetotransport in Dirac-Weyl magnetic junctions
Creators: name: Ominato, Yuya
name: Kobayashi, Koji
name: Nomura, Kentaro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We theoretically study the anisotropic magnetotransport in Dirac-Weyl magnetic junctions where a doped ferromagnetic Weyl semimetal is sandwiched between doped Dirac semimetals. We calculate the conductance using the Landauer formula and find that the system exhibits extraordinarily large anisotropic magnetoresistance (AMR). The AMR depends on the ratio of the Fermi energy and the strength of the exchange interaction. The origin of the AMR is the shift of the Fermi surface in the Weyl semimetal and the mechanism is completely different from the conventional AMR originating from the spin dependent scattering and the spin-orbit interaction.
description: 7 pages, 5 figures
Positive reappraisal in older adults: exploration of a cognitive emotion regulation strategy
Creators: name: Nowlan, Jamie S.
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: Positive reappraisal is an adaptive cognitive emotion regulation strategy that is relevant for older adults and may facilitate coping with ageing-related stressors. This thesis examined the construct of positive reappraisal in older adulthood, specifically investigating how emotion and time since stressor occurrence relate to use of the strategy and whether positive reappraisal can be used therapeutically to facilitate coping with chronic physical illness. Given the lack of systematic reviews on positive reappraisal or its measurement, the first two papers in the thesis comprised two systematic literature reviews, firstly evaluating the construct of positive reappraisal in older adulthood and secondly examining self-report questionnaires that measure positive reappraisal validly and reliably. The third paper in the thesis explored the mechanisms underpinning the positive reappraisal strategy across two separate studies (retrospective and prospective) with a particular emphasis on its relationship with emotion over time. The fourth paper in the thesis comprised a pilot study of a structured intervention to examine whether the positive reappraisal strategy could be taught to older adults to increase their use of positive reappraisal. The final paper in the thesis used a randomised controlled trial design to examine whether a single-session positive reappraisal intervention for chronically-ill older adults would increase positive reappraisal use more than cognitive restructuring or supportive counselling. Results from this thesis indicate that positive reappraisal is an adaptive coping strategy for older adults, particularly relating to increased positive emotion, is associated with increased use and benefit over time since stressor occurrence, and can be increased in older adults with a structured single-session intervention. The thesis furthers our understanding of late-life positive reappraisal, demonstrates that it is an adaptive coping strategy for older adults, and provides evidence for a novel therapeutic technique to increase the use of positive reappraisal with older adult populations.
A First-Principles Explanation of the Luminescent Line Shape of SrLiAl$_3$N$_4$:Eu$^{2+}$ Phosphor for Light-Emitting Diode Applications
Creators: name: Bouquiaux, Julien
name: Poncé, Samuel
name: Jia, Yongchao
name: Miglio, Anna
name: Mikami, Masayoshi
name: Gonze, Xavier
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: White light-emitting diodes are gaining popularity and are set to become the most common light source in the U.S. by 2025. However, their performance is still limited by the lack of an efficient red-emitting component with a narrow band emission. The red phosphor SrLiAl$_3$N$_4$:Eu$^{2+}$ is among the first promising phosphors with a small bandwidth for next-generation lighting, but the microscopic origin of this narrow emission remains elusive. In the present work, density functional theory, the $Δ$SCF-constrained occupation method, and a generalized Huang-Rhys theory are used to provide an accurate description of the vibronic processes occurring at the two Sr$^{2+}$ sites that the Eu$^{2+}$ activator can occupy. The emission band shape of Eu(Sr1), with a zero-phonon line at 1.906 eV and a high luminescence intensity, is shown to be controlled by the coupling between the 5d$_{z^2}$-4f electronic transition and the low-frequency phonon modes associated with the Sr and Eu displacements along the Sr channel. The good agreement between our computations and experimental results allows us to provide a structural assignment of the observed total spectrum. By computing explicitly the effect of the thermal expansion on zero-phonon line energies, the agreement is extended to the temperature-dependent spectrum. These results provide insight into the electron-phonon coupling that accompanies the 5d-4f transition in similar UCr$_4$C$_4$-type phosphors. Furthermore, these results highlight the importance of the Sr channel in shaping the narrow emission of SrLiAl$_3$N$_4$:Eu$^{2+}$, and they shed new light on the structure-property relations of such phosphors.
description: 10 pages, 6 figures
BERT-Deep CNN: State-of-the-Art for Sentiment Analysis of COVID-19 Tweets
Creators: name: Joloudari, Javad Hassannataj
name: Hussain, Sadiq
name: Nematollahi, Mohammad Ali
name: Bagheri, Rouhollah
name: Fazl, Fatemeh
name: Alizadehsani, Roohallah
name: Lashgari, Reza
name: Talukder, Ashis
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: The free flow of information has been accelerated by the rapid development of social media technology. There has been a significant social and psychological impact on the population due to the outbreak of Coronavirus disease (COVID-19). The COVID-19 pandemic is one of the current events being discussed on social media platforms. In order to safeguard societies from this pandemic, studying people's emotions on social media is crucial. As a result of their particular characteristics, sentiment analysis of texts like tweets remains challenging. Sentiment analysis is a powerful text analysis tool. It automatically detects and analyzes opinions and emotions from unstructured data. Texts from a wide range of sources are examined by a sentiment analysis tool, which extracts meaning from them, including emails, surveys, reviews, social media posts, and web articles. To evaluate sentiments, natural language processing (NLP) and machine learning techniques are used, which assign weights to entities, topics, themes, and categories in sentences or phrases. Machine learning tools learn how to detect sentiment without human intervention by examining examples of emotions in text. In a pandemic situation, analyzing social media texts to uncover sentimental trends can be very helpful in gaining a better understanding of society's needs and predicting future trends. We intend to study society's perception of the COVID-19 pandemic through social media using state-of-the-art BERT and Deep CNN models. The superiority of BERT models over other deep models in sentiment analysis is evident and can be concluded from the comparison of the various research studies mentioned in this article.
description: 20 pages, 5 figures
Whose Emotion Matters? Speaking Activity Localisation without Prior Knowledge
Creators: name: Carneiro, Hugo
name: Weber, Cornelius
name: Wermter, Stefan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Sound (cs.SD)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: I.2.0
subject: 68T20

description: The task of emotion recognition in conversations (ERC) benefits from the availability of multiple modalities, as provided, for example, in the video-based Multimodal EmotionLines Dataset (MELD). However, only a few research approaches use both acoustic and visual information from the MELD videos. There are two reasons for this: First, label-to-video alignments in MELD are noisy, making those videos an unreliable source of emotional speech data. Second, conversations can involve several people in the same scene, which requires the localisation of the utterance source. In this paper, we introduce MELD with Fixed Audiovisual Information via Realignment (MELD-FAIR) by using recent active speaker detection and automatic speech recognition models, we are able to realign the videos of MELD and capture the facial expressions from speakers in 96.92% of the utterances provided in MELD. Experiments with a self-supervised voice recognition model indicate that the realigned MELD-FAIR videos more closely match the transcribed utterances given in the MELD dataset. Finally, we devise a model for emotion recognition in conversations trained on the realigned MELD-FAIR videos, which outperforms state-of-the-art models for ERC based on vision alone. This indicates that localising the source of speaking activities is indeed effective for extracting facial expressions from the uttering speakers and that faces provide more informative visual cues than the visual features state-of-the-art models have been using so far. The MELD-FAIR realignment data, and the code of the realignment procedure and of the emotional recognition, are available at https://github.com/knowledgetechnologyuhh/MELD-FAIR.
description: 17 pages, 8 figures, 7 tables, Published in Neurocomputing
Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center
Creators: name: Shahzamanian, B.
name: Eckart, A.
name: Zajacek, M.
name: Valencia-S., M.
name: Sabha, N.
name: Moser, L.
name: Parsa, M.
name: Peissker, F.
name: Straubmeier, C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate an infrared-excess source called G2 or Dusty S-cluster Object (DSO) moving on a highly eccentric orbit around the Galaxy's central black hole, Sgr A*. We use, for the first time, near-infrared polarimetric imaging data to determine the nature and the properties of the DSO, and obtain an improved K_s-band identification of this source in median polarimetry images of different observing years. The source starts to deviate from the stellar confusion in 2008, and it does not show any flux density variability over the years we analyzed it. We measure the polarization degree and angle of the DSO between 2008 and 2012 and conclude, based on the significance analysis on polarization parameters, that it is an intrinsically polarized source (>20%) with a varying polarization angle as it approaches Sgr A* position. DSO shows a near-infrared excess of K_s-L' > 3 that remains compact close to the pericenter of its orbit. Its observed parameters and the significant polarization obtained in this work show that the DSO might be a dust-enshrouded young star, forming a bow shock as it approaches the super massive black hole. The significantly high measured polarization degree indicates that it has a non-spherical geometry and it can be modelled as a combination of a bow shock with a bipolar wind of the star. We use a 3D radiative transfer model that can reproduce the observed properties of the source such as the total flux density and the polarization degree. We obtain that the change of the polarization angle can be due to an intrinsic change in the source structure. Accretion disc precession of the young star in the gravitational field of the black hole can lead to the change of the bipolar outflow and therefore the polarization angle variation. It might also be the result of the source interaction with the ambient medium.
description: 15 pages, 12 figures, Accepted to be published in Astronomy & Astrophysics
Adult illiteracy : four case-studies
Creators: name: Sabto, Jeanette Gina
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 Reference field.
Valence Fluctuations in the Extended Anderson Lattice Model with Quasiperiodicity
Creators: name: Shinzaki, Ryu
name: Nasu, Joji
name: Koga, Akihisa
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study valence fluctuations in the extended Anderson model on two-dimensional Penrose lattice, using the real-space dynamical mean-field theory combined with the continuous-time Monte Carlo method. Calculating $f$-electron number, $c$-$f$ spin correlations, and magnetic susceptibility at each site, we find site-dependent formations of the singlet state and valence distribution at low temperatures, which are reflected by the quasiperiodic lattice structure. The bulk magnetic susceptibility is also addressed.
description: 6 pages, 5 figures