cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Benchmark solutions for transport in $d$-dimensional Markov binary mixtures
Creators: name: Larmier, Coline
name: Hugot, F-X
name: Malvagi, Fausto
name: Mazzolo, Alain
name: Zoia, Andrea
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Linear particle transport in stochastic media is key to such relevant applications as neutron diffusion in randomly mixed immiscible materials, light propagation through engineered optical materials, and inertial confinement fusion, only to name a few. We extend the pioneering work by Adams, Larsen and Pomraning \cite{benchmark_adams} (recently revisited by Brantley \cite{brantley_benchmark}) by considering a series of benchmark configurations for mono-energetic and isotropic transport through Markov binary mixtures in dimension $d$. The stochastic media are generated by resorting to Poisson random tessellations in $1d$ slab, $2d$ extruded, and full $3d$ geometry. For each realization, particle transport is performed by resorting to the Monte Carlo simulation. The distributions of the transmission and reflection coefficients on the free surfaces of the geometry are subsequently estimated, and the average values over the ensemble of realizations are computed. Reference solutions for the benchmark have never been provided before for two- and three-dimensional Poisson tessellations, and the results presented in this paper might thus be useful in order to validate fast but approximated models for particle transport in Markov stochastic media, such as the celebrated Chord Length Sampling algorithm.
description: 21 pages, 12 figures
Search for primordial black hole dark matter with X-ray spectroscopic and imaging satellite experiments and prospects for future satellite missions
Creators: name: Malyshev, Denys
name: Moulin, Emmanuel
name: Santangelo, Andrea
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Ultra-light primordial black holes (PBHs) in the mass range of 10$^{16}$ - 10$^{22}$ g are allowed by current observations to constitute a significant fraction, if not all, of the dark matter in the Universe. In this work, we present limits on ultra-light, non-rotating PBHs which arise from the non-detection of the Hawking radiation signals from such objects in the keV-MeV energy band. Namely, we consider observations from the current-generation missions XMM-Newton and INTEGRAL/SPI and discuss the observational perspectives of the future missions Athena, eXTP, and THESEUS for PBH searches. Based on 3.4 Msec total exposure time XMM-Newton observations of Draco dwarf spheroidal galaxy, we conclude that PBH with masses $\lesssim 10^{16}$ g can not make all dark matter at 95% confidence level. Our ON-OFF-type analysis of $>100$ Msec of INTEGRAL/SPI data on the Milky Way halo puts significantly stronger constraints. Only $\lesssim 10$% dark matter can be presented by PBHs with masses $\lesssim 3\cdot 10^{16}$ g while the majority of dark matter can not be represented by PBHs lighter than $7\cdot 10^{16}$ g at 95% confidence level. We discuss the strong impact of systematic uncertainty related to the variations of instrumental and astrophysical INTEGRAL/SPI background on the derived results and estimate its level. We also show that future large-field-of-view missions such as THESEUS/X-GIS will be able to improve the constraints by a factor of 10-100 depending on the level of control under the systematics of these instruments.
description: To match accepted for publication in Phys. Rev. D. version
A reconnection-driven model of the hard X-ray loop-top source from flare 2004-Feb-26
Creators: name: Longcope, Dana
name: Qiu, Jiong
name: Brewer, Jasmine
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A compact X-class flare on 2004-Feb-26 showed a concentrated source of hard X-rays at the tops of the flare's loops. This was analyzed in previous work (Longcope et al. 2010), and interpreted as plasma heated and compressed by slow magnetosonic shocks generated during post-reconnection retraction of the flux. That work used analytic expressions from a thin flux tube (TFT) model, which neglected many potentially important factors such as thermal conduction and chromospheric evaporation. Here we use a numerical solution of the TFT equations to produce a more comprehensive and accurate model of the same flare, including those effects previously omitted. These simulations corroborate the prior hypothesis that slow mode shocks persist well after the retraction has ended, thus producing a compact, loop-top source instead of an elongated jet, as steady reconnection models predict. Thermal conduction leads to densities higher than analytic estimates had predicted, and evaporation enhances the density still higher, but at lower temperatures. X-ray light curves and spectra are synthesized by convolving the results from a single TFT simulation with the rate at which flux is reconnected, as measured through motion of flare ribbons, for example. These agree well with light curves observed by RHESSI and GOES and spectra from RHESSI. An image created from a superposition of TFT model runs resembles one produced from RHESSI observations. This suggests that the HXR loop-top source, at least the one observed in this flare, could be the result of slow magnetosonic shocks produced in fast reconnection models like Petschek's.
Void filled square steel tubes subjected to large deflection pure bending
Creators: name: Kilner, Andrew A. .
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
title: Generalised state estimators for robotic platforms through the use of improved sensor characterisation and variance modelling.
Creators: name: Pointon, H
Publisher: name: Liverpool John Moores University
Year: 2020

description: The aim of this research is to develop an improved representation of the sensor variance in a state estimator and assess its viability in conjunction with generalised system models. This would enable the use of a single state estimation system across many different platforms. A key challenge in the safe deployment of \gls{uav} systems is localisation. In built up environments traditional \gls{GNSS} systems become unreliable, and other sensing systems are often limited in application. Deploying \gls{uav} platforms in complex or safety critical operations often requires a legal exemption, with a demonstration of robust, practical operation of the equipment proposed. To this end, a generalised state estimator would allow repeated use of the same, experimentally validated systems. This research presents a methodology to characterise the principle input sensor, in this case, an UWB system through the use of the RTS. The project continues, by demonstrating the implementation of a sensor variance model in the commonly used EKF framework, in both ground and aerial platforms. The work concludes, with a demonstration of a generalised state estimator in use for both a ground and aerial platform, and shows a more stable, noise tolerant output, assessed using the RTS system.
A semi-supervised Teacher-Student framework for surgical tool detection and localization
Creators: name: Ali, Mansoor
name: Ochoa-Ruiz, Gilberto
name: Ali, Sharib
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Surgical tool detection in minimally invasive surgery is an essential part of computer-assisted interventions. Current approaches are mostly based on supervised methods which require large fully labeled data to train supervised models and suffer from pseudo label bias because of class imbalance issues. However large image datasets with bounding box annotations are often scarcely available. Semi-supervised learning (SSL) has recently emerged as a means for training large models using only a modest amount of annotated data; apart from reducing the annotation cost. SSL has also shown promise to produce models that are more robust and generalizable. Therefore, in this paper we introduce a semi-supervised learning (SSL) framework in surgical tool detection paradigm which aims to mitigate the scarcity of training data and the data imbalance through a knowledge distillation approach. In the proposed work, we train a model with labeled data which initialises the Teacher-Student joint learning, where the Student is trained on Teacher-generated pseudo labels from unlabeled data. We propose a multi-class distance with a margin based classification loss function in the region-of-interest head of the detector to effectively segregate foreground classes from background region. Our results on m2cai16-tool-locations dataset indicate the superiority of our approach on different supervised data settings (1%, 2%, 5%, 10% of annotated data) where our model achieves overall improvements of 8%, 12% and 27% in mAP (on 1% labeled data) over the state-of-the-art SSL methods and a fully supervised baseline, respectively. The code is available at https://github.com/Mansoor-at/Semi-supervised-surgical-tool-det
description: Paper accepted at Augmented Reality, Augmented Environments for Computer Assisted Interventions (AE-CAI), Computer Assisted and Robotic Endoscopy (CARE) and Context-Aware Operating Theaters (OR 2.0) at MICCAI 2022
title: A RISK-BASED VERIFICATION FRAMEWORK FOR OFFSHORE WIND FARM DEVELOPMENT: DESIGN, INSTALLATION, OPERATIONS AND MAINTENANCE OF OFFSHORE WIND TURBINES
Creators: name: Ikewete, I
Publisher: name: Liverpool John Moores University
Year: 2020

description: This thesis encompasses a holistic review of the development trends in wind turbine technology (onshore and offshore) and the challenges perceived at the stages of design, construction and operations of modern-day wind energy technology (Friedrich and Lukas, 2017). The main focus of this study is to evaluate the risks associated with offshore wind farm development (OWFD). This is achieved by first estimating those perceived risks, understanding the relative importance of each individual risk, and carrying out an assessment using a specialist analytical tool known as AHiP-Evi. AHiP-Evi was developed through a combination of application of Analytic Hierarchy Process (AHP) and Evidential Reasoning (ER) techniques. The AHP was used to ascertain the weighting of the respective risk variables according to their relative importance, while the ER was used to evaluate the aggregated influence of the collective risk variables associated with the OWFD. Finally, a specific modelling tool known as BN-SAT (Bayesian Network Sensitivity Analysis Technique) was developed to evaluate the probabilities of occurrence of the variable nodes and their overall impacts on the decision node (OWFD). The BN-SAT is comprised of a combination of Bayesian networks (BNs) concepts and a sensitivity analysis (SA) approach. The AHiP-Evi model initially developed in this study is transformed into the BN structure in order to compute the conditional and unconditional prior probability for each starting node using the NETICA analytical software to determine the aggregated impact of the specific risk variables on the OWFD. The outcome from this modelling analysis is then compared to the initial assessment carried out by the application of the AHiP-Evi modelling tool in order to validate the robustness of both modelling tools. In the case study of this research, the percentage difference of the outcomes of the two models is insignificant, which demonstrates the fact that both systems are effective. The Fuzzy Analytic Hierarchy Process (FAHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) were integrated to develop a specific model for the selection of best-case risk management technique (RMT). Based on the decision makers’ (DMs) aggregated judgements, it was possible to compute the values and determine the best-case RMT dependent on the decision variables driving the decision - for example, costs and benefits, through the developed integrated model known as FAHP-FTOPSIS. The outcome of this selection model has been seen to be reasonably practical and a successful conclusion of the research contribution. Awareness of the aggregated impact of the risk variables is important in making the decision about appropriate investments in a strategic improvement of risk management and efficient resource allocations to the offshore wind industry.
Severe signal loss in diamond beam loss monitors in high particle rate environments by charge trapping in radiation-induced defects
Creators: name: Kassel, Florian
name: Guthoff, Moritz
name: Dabrowski, Anne
name: de Boer, Wim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The beam condition monitoring leakage (BCML) system is a beam monitoring device in the compact muon solenoid (CMS) experiment at the large hadron collider (LHC). As detectors 32 poly-crystalline (pCVD) diamond sensors are positioned in rings around the beam pipe. Here, high particle rates occur from the colliding beams scattering particles outside the beam pipe. These particles cause defects, which act as traps for the ionization, thus reducing the charge collection efficiency (CCE). However, the loss in CCE was much more severe than expected from low rate laboratory measurements and simulations, especially in single-crystalline (sCVD) diamonds, which have a low initial concentration of defects. The reason why in real experiments the CCE is much worse than in laboratory experiments is related to the ionization rate. At high particle rates the trapping rate of the ionization is so high compared with the detrapping rate, that space charge builds up. This space charge reduces locally the internal electric field, which in turn increases the trapping rate and recombination and hence reduces the CCE in a strongly non-linear way. A diamond irradiation campaign was started to investigate the rate dependent electrical field deformation with respect to the radiation damage. Besides the electrical field measurements via the Transient Current Technique (TCT), the CCE was measured. The experimental results were used to create an effective deep trap model that takes the radiation damage into account. Using this trap model the rate dependent electrical field deformation and the CCE were simulated with the software SILVACO TCAD. The simulation, tuned to rate dependent measurements from a strong radioactive source, was able to predict the non-linear decrease of the CCE in the harsh environment of the LHC, where the particle rate was a factor 30 higher.
description: 9 pages, 14 figures, Physica Status Solidi A, 2016
Unified theory of electron-phonon renormalization and phonon-assisted optical absorption
Creators: name: Patrick, Christopher E.
name: Giustino, Feliciano
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a theory of electronic excitation energies and optical absorption spectra which incorporates energy-level renormalization and phonon-assisted optical absorption within a unified framework. Using time-independent perturbation theory we show how the standard approaches for studying vibronic effects in molecules and those for addressing electron-phonon interactions in solids correspond to slightly different choices for the non-interacting Hamiltonian. Our present approach naturally leads to the Allen-Heine theory of temperature-dependent energy levels, the Franck-Condon principle, the Herzberg-Teller effect and to phonon-assisted optical absorption in indirect band gap materials. In addition, our theory predicts sub-gap phonon-assisted optical absorption in direct gap materials, as well as an exponential edge which we tentatively assign to the Urbach tail. We also consider a semiclassical approach to the calculation of optical absorption spectra which simultaneously captures energy-level renormalization and phonon-assisted transitions and is especially suited to first-principles electronic structure calculations. We demonstrate this approach by calculating the phonon-assisted optical absorption spectrum of bulk silicon.
description: This is an author-created, un-copyedited version of an article published in J. Phys.: Condens. Matter. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0953-8984/26/36/365503
Dicke phase transition without total spin conservation
Creators: name: Torre, Emanuele G. Dalla
name: Shchadilova, Yulia
name: Wilner, Eli Y.
name: Lukin, Mikhail D.
name: Demler, Eugene
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We develop a new fermionic path-integral formalism to analyze the phase diagram of open nonequilibrium systems. The formalism is applied to analyze an ensemble of two-level atoms interacting with a single-mode optical cavity, described by the Dicke model. While this model is often used as the paradigmatic example of a phase transition in driven-dissipative systems, earlier theoretical studies were limited to the special case when the total spin of the atomic ensemble is conserved. This assumption is not justified in most experimental realizations. Our new approach allows us to analyze the problem in a more general case, including the experimentally relevant case of dissipative processes that act on each atom individually and do not conserve the total spin. We obtain a general expression for the position of the transition, which contains as special cases the two previously known regimes: i) non-equilibrium systems with losses and conserved spin and ii) closed systems in thermal equilibrium and with the Gibbs ensemble averaging over the values of the total spin. We perform a detailed study of different types of baths and point out the possibility of a surprising non-monotonous dependence of the transition on the baths' parameters.
description: 6 pages. Comments welcome
CA-CentripetalNet: A novel anchor-free deep learning framework for hardhat wearing detection
Creators: name: Liu, Zhijian
name: Cai, Nian
name: Ouyang, Wensheng
name: Zhang, Chengbin
name: Tian, Nili
name: Wang, Han
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Automatic hardhat wearing detection can strengthen the safety management in construction sites, which is still challenging due to complicated video surveillance scenes. To deal with the poor generalization of previous deep learning based methods, a novel anchor-free deep learning framework called CA-CentripetalNet is proposed for hardhat wearing detection. Two novel schemes are proposed to improve the feature extraction and utilization ability of CA-CentripetalNet, which are vertical-horizontal corner pooling and bounding constrained center attention. The former is designed to realize the comprehensive utilization of marginal features and internal features. The latter is designed to enforce the backbone to pay attention to internal features, which is only used during the training rather than during the detection. Experimental results indicate that the CA-CentripetalNet achieves better performance with the 86.63% mAP (mean Average Precision) with less memory consumption at a reasonable speed than the existing deep learning based methods, especially in case of small-scale hardhats and non-worn-hardhats.
description: It has been accepted for the journal of Signal, Image and Video Processing, which is a complete version. It is noted that it has been deleted for future publishing
Arrested development
Creators: name: Sapp, Christopher
Publisher: name: Journal of Historical Syntax
Year: 2020

description: Old Icelandic relative clauses are frequently preceded by the pronoun sá, considered by most grammars to be a demonstrative. Using a large corpus of Old Icelandic prose, I show that when sá precedes relative clauses, it is often ambiguous between a cataphoric demonstrative (referring ahead to a relative clause) and relative pronoun (part of the relative clause). Syntactic and prosodic evidence indicates that, at least in some instances, sá is unambiguously a relative pronoun, used in tandem with the particle er; thus Old Icelandic relative clauses seem to have doubly filled COMP. A notable characteristic of relative sá is its pervasive attraction to the case of the matrix antecedent. I argue that case attraction represents an intermediate stage in the reanalysis of sá from a demonstrative to a true relative pronoun. Structurally, case-attracting relative pronouns and true relative pronouns occupy different functional positions within a split-CP system. Sá achieved the final stage of the development in the seventeenth century, but rapidly declined under competition with the complementizer sem, thus leaving the false impression that sá never developed beyond the case-attraction stage.
description: Journal of Historical Syntax, Language 95 (1)
Anderson localization of emergent quasiparticles: Spinon and vison interplay at finite temperature in a $\mathbb{Z}_2$ gauge theory in three dimensions
Creators: name: Kim, Minho
name: De Tomasi, Giuseppe
name: Castelnovo, Claudio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Fractional statistics of quasiparticle excitations often plays an important role in the detection and characterization of topological systems. In this paper, we investigate the case of a three-dimensional (3D) Z2 gauge theory, where the excitations take the form of bosonic spinon quasiparticle and vison flux tubes, with mutual semionic statistics. We focus on an experimentally relevant intermediate temperature regime, where sparse spinons hop coherently on a dense quasistatic and stochastic vison background. The effective Hamiltonian reduces to a random-sign bimodal tight-binding model, where both the particles and the disorder are borne out of the same underlying quantum spin liquid (QSL) degrees of freedom, and the coupling between the two is purely driven by the mutual fractional statistics. We study the localization properties and observe a mobility edge located close to the band edge, whose transition belongs to the 3D Anderson model universality class. Spinons allowed to propagate through the quasistatic vison background appear to display quantum diffusive behavior. When the visons are allowed to relax, in response to the presence of spinons in equilibrium, we observe the formation of vison depletion regions slave to the support of the spinon wavefunction. We discuss how this behavior can give rise to measurable effects in the relaxation, response and transport properties of the system and how these may be used as signatures of the mutual semionic statistics and as precursors of the QSL phase arising in the system at lower temperatures.
description: 18 pages, 15 figures. Accepted to Phys. Rev. Research on 15 Nov 2022. Current version is after final proofs
Gravitational Waves from Pulsars and Their Braking Indices: The Role of a Time Dependent Magnetic Ellipticity
Creators: name: de Araujo, José C. N.
name: Coelho, Jaziel G.
name: Costa, César A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the role of time dependent magnetic ellipticities ($ε_{B}$) on the calculation of the braking index of pulsars. Moreover, we study the consequences of such a $ε_{B}$ on the amplitude of gravitational waves (GWs) generated by pulsars with measured braking indices. We show that, since the ellipticity generated by the magnetic dipole is extremely small, the corresponding amplitude of GWs is much smaller than the amplitude obtained via the spindown limit.
description: 5 pages, 1 figure. arXiv admin note: text overlap with arXiv:1607.05315
Incorporating flexibility of tubular connections in structural analyses
Creators: name: Eadie, Ian McLean.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
String-like Theory of Quantum Hall Interfaces
Creators: name: Turker, Oguz
name: Yang, Kun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We derive the effective theories for quantum hall droplets with attractive interaction among the constituent particles. In the absence of confining potentials such droplets are defined by their freely moving interfaces (or boundaries) with the vacuum. We demonstrate the effective theories take forms similar to string theories. Generalization to interfaces between different quantum Hall liquids is discussed.
description: 6 pages, 3 Figures
Structure of a Water Monolayer on the Anatase TiO$_2$(101) Surface
Creators: name: Patrick, Christopher E.
name: Giustino, Feliciano
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Titanium dioxide (TiO$_2$) plays a central role in the study of artificial photosynthesis, owing to its ability to perform photocatalytic water splitting. Despite over four decades of intense research efforts in this area, there is still some debate over the nature of the first water monolayer on the technologically-relevant anatase TiO$_2$ (101) surface. In this work we use first-principles calculations to reverse-engineer the experimental high-resolution X-ray photoelectron spectra measured for this surface in [Walle et al., J. Phys. Chem. C 115, 9545 (2011)], and find evidence supporting the existence of a mix of dissociated and molecular water in the first monolayer. Using both semilocal and hybrid functional calculations we revise the current understanding of the adsorption energetics by showing that the energetic cost of water dissociation is reduced via the formation of a hydrogen-bonded hydroxyl-water complex. We also show that such a complex can provide an explanation of an unusual superstructure observed in high-resolution scanning tunneling microscopy experiments.
description: 11 pages, 9 figures. Published in Phys. Rev. Appl. by the American Physical Society (2014)
Spin-filtering in a $p$-orbital helical atomic chain
Creators: name: Utsumi, Yasuhiro
name: Kato, Takemitsu
name: Entin-Wohlman, Ora
name: Aharony, Amnon
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We theoretically analyze spin filtering in two-terminal systems, induced by the spin-orbit interaction (SOI), as a possible origin of the ``chirality-induced spin selectivity'' (CISS) effect observed experimentally in chiral molecules, such as DNA. Due to Bardarson's theorem, spin filtering cannot be realized in a molecule containing one orbital-channel. However, when two orbitals are involved, SOI can induce spin filtering in a molecule coupled to two terminals without braking time-reversal symmetry. In particular, we provide an example of a $4 \times 4$ reflection matrix for a spinful electron passing through a molecule containing two orbital-channels, which complies with Bardarson's theorem and produces a finite spin conductance. As a microscopic toy model realizing a single strand of DNA, we consider a $p$-orbital helical atomic chain with intra-atomic SOI's and a strong crystalline field along the helix. This model exhibits two-orbital spin filtering: For various parameters preserving the helical symmetry, the model hosts spin asymmetric states carrying pairs of up and down spins propagating in opposite directions. The typical energy scale of the helical states is the product of the intra-atomic SOI and the curvature. The large value of this energy identifies our model as a likely candidate to explain the CISS in organic molecules.
description: 6 pages, 3 figures
Distribution system reliability assessment taking circuit capacity into consideration
Creators: name: Cheung, Joseph Nai-Yee.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
On the resonant detonation of sub-Chandrasekhar mass white dwarfs during binary inspiral
Creators: name: McKernan, B.
name: Ford, K. E. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: White dwarfs (WDs) are believed to detonate via explosive Carbon-fusion in a Type Ia Supernova when their temperature and/or density reach the point where Carbon is ignited in a runaway reaction. Observations of the Type Ia supernova (SN) rate imply all WD binaries that merge through the emission of gravitational radiation within a Hubble time should result in SNe, regardless of total mass. Here we investigate the conditions under which a single WD in a binary system might extract energy from its orbit, depositing enough energy into a resonant mode such that it detonates before merger. We show that, ignoring non-linear effects, in a WD binary in tidal lock at small binary separations, the sustained tidal forcing of a low-order quadrupolar g-mode or a harmonic of a low-order quadrupolar p-mode could in principle drive the average temperature of Carbon nuclei in the mode over the runaway fusion threshold. If growing mode energy is thermalized at a core/atmosphere boundary, rapid Helium burning and inward-travelling p-waves may result in core detonation. Thermalization at a boundary in the core can also result in detonation. If energy can be efficiently transferred from the orbit to modes as the WD binary passes through resonances, the WD merger timescale will be shortened by Myr-Gyr compared to expected timescales from GW-emission alone and GW detectors will observe deviations from predicted chirp profiles in resolved WD binaries. Future work in this area should focus on whether tidal locking in WD binaries is naturally driven towards low-order mode frequencies.
description: 8 pages, 1 figure. MNRAS (accepted)
New recursions for tree-level correlators in (Anti) de Sitter space
Creators: name: Armstrong, Connor
name: Gomez, Humberto
name: Jusinskas, Renann Lipinski
name: Lipstein, Arthur
name: Mei, Jiajie
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: We present for the first time classical multiparticle solutions in Anti de Sitter space (AdS) involving scalars, gluons, and gravitons. They are recursively defined through multiparticle currents which reduce to Berends-Giele currents in the flat space limit. This construction exposes a compact definition of tree-level boundary correlators using a general prescription that removes unphysical boundary contributions. Similarly to the flat space perturbiner, a convenient gauge choice leads to a scalar basis for all degrees of freedom, while the tensor structure is exclusively captured by field theory vertices. This provides a fully automated way to compute AdS boundary correlators to any multiplicity and cosmological wavefunction coefficients after Wick-rotating to de Sitter space.
description: 9 pages. v2: references added. v3: published version, with fixed typo in equation (37)
Multi-D magnetohydrodynamic modelling of pulsar wind nebulae: recent progress and open questions
Creators: name: Olmi, B.
name: Del Zanna, L.
name: Amato, E.
name: Bucciantini, N.
name: Mignone, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In the last decade, the relativistic magnetohydrodynamic (MHD) modelling of pulsar wind nebulae, and of the Crab nebula in particular, has been highly successful, with many of the observed dynamical and emission properties reproduced down to the finest detail. Here, we critically discuss the results of some of the most recent studies: namely the investigation of the origin of the radio emitting particles and the quest for the acceleration sites of particles of different energies along the termination shock, by using wisps motion as a diagnostic tool; the study of the magnetic dissipation process in high magnetization nebulae by means of new long-term three-dimensional simulations of the pulsar wind nebula evolution; the investigation of the relativistic tearing instability in thinning current sheets, leading to fast reconnection events that might be at the origin of the Crab nebula gamma-ray flares.
description: 30 pages, 12 figures
On The Impact of Machine Learning Randomness on Group Fairness
Creators: name: Ganesh, Prakhar
name: Chang, Hongyan
name: Strobel, Martin
name: Shokri, Reza
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Statistical measures for group fairness in machine learning reflect the gap in performance of algorithms across different groups. These measures, however, exhibit a high variance between different training instances, which makes them unreliable for empirical evaluation of fairness. What causes this high variance? We investigate the impact on group fairness of different sources of randomness in training neural networks. We show that the variance in group fairness measures is rooted in the high volatility of the learning process on under-represented groups. Further, we recognize the dominant source of randomness as the stochasticity of data order during training. Based on these findings, we show how one can control group-level accuracy (i.e., model fairness), with high efficiency and negligible impact on the model's overall performance, by simply changing the data order for a single epoch.
description: 10 pages + Appendix
Three dimensional analysis of wear particle morphology
Creators: name: Xu, Zheng Long.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Orthogonal run-and-tumble walks
Creators: name: Angelani, Luca
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Planar run-and-tumble walks with orthogonal directions of motion are considered. After formulating the problem with generic transition probabilities among the orientational states, we focus on the symmetric case, giving general expressions of the probability distribution function (in the Laplace-Fourier domain), the mean square displacement and the effective diffusion constant in terms of transition rate parameters. As case studies we treat and discuss two classes of motion, alternate/forward and isotropic/backward, obtaining, when possible, analytic expressions of probability distribution functions in the space-time domain. We discuss at the end also the case of cyclic motion. Reduced (enhanced) effective diffusivity, with respect to the standard 2D active motion, is observed in the cyclic and backward (forward) cases.
description: 17 pages
Color Dipole Picture of Deep Inelastic Scattering, Revisited
Creators: name: Kuroda, Masaaki
name: Schildknecht, Dieter
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Based upon the color-dipole picture, we provide closed analytic expressions for the longitudinal and the transverse photoabsorption cross sections at low values of the Bjorken variable of x<0.1. We compare with the experimental data for the longitudinal-to-transverse ratio of the (virtual) photoabsorption cross section and with our previous fit to the experimental data for the total photoabsorption cross section. Scaling in terms of the low-x scaling variable eta(W^2,Q^2) is analyzed in terms of the reduced cross section of deep inelastic scattering.
Gray-body factor and absorption of the Dirac field in ESTGB gravity
Creators: name: Li, Qian
name: Ma, Chen
name: Zhang, Yu
name: Lin, Zhi-Wen
name: Duan, Peng-Fei
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The gray-body factor and the absorption cross section of the 4D ESTGB gravity with a mode of nonlinear electrodynamics for the massless Dirac field are studied in this paper. The magnetic charge value varies between $-2^{(\frac{5}{3})}/3$ and $0$ as well as the ADM mass is set to $1$, which corresponds to a non-extreme black hole. The gray-body factor is obtained using the semi-analytic WKB method after solving the massless Dirac equation. When the absolute value of magnetic charge is increasing, the gray-body factor $γ(ω)$ is decreasing. In addition, the partial absorption cross section and the total absorption cross section are calculated by using the partial wave method. We find that the maximum value of partial absorption cross section decreases as $κ$ increases. And the existence of magnetic charge causes the diminishing of the total absorption cross section. Finally, we find that the absorption cross section of the Dirac field is more sensitive to electric charge than magnetic charge by comparing the absorption cross section of the Reissner-Nordstr$\rm\ddot{o}$m and ESTGB-NLED black holes.
description: 11 pages, 7 figures
Low cost multi-purpose balloon-borne platform for wide-field imaging and video observation
Creators: name: Ocaña, Francisco
name: de Miguel, Alejandro Sánchez
name: Conde, Aitor
name: Team, Daedalus
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Atmosphere layers, especially the troposphere, hinder the astronomical observation. For more than 100 years astronomers have tried observing from balloons to avoid turbulence and extinction. New developments in cardsize computers, RF equipment and satellite navigation have democratised the access to the stratosphere. As a result of a ProAm collaboration with the Daedalus Team we have developed a low-cost multi-purpose platform with stratospheric balloons carrying up to 3 kg of scientific payload. The Daedalus Team is an amateur group that has been launching sounding probes since 2010. Since then the first two authors have provided scienti fic payloads for nighttime flights with the purpose of technology demonstration for astronomical observation. We have successfully observed meteor showers (Geminids 2012, Camelopardalis 2014, Quadrantids 2016 and Lyrids 2016) and city light pollution emission with image and video sensors covering the 400-1000nm range.
description: 9 pages, 6 figures
Kamimuria atra Sivec & Stark 2008
Creators: name: Li, Kefan
name: Wang, Bingli
name: Bozdoğan, Hakan
name: Li, Weihai
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Perlidae
Kamimuria
Kamimuria atra

description: Kamimuria atra Sivec & Stark, 2008 (Fig. 1) http://lsid.speciesfile.org/urn:lsid: Plecoptera.speciesfile.org:TaxonName:2313 Kamimuria atra Sivec & Stark 2008:111. Holotype male (Slovenian Museum of Natural History, Ljubljana), Huai Sai Leung, Doi Inthanon National Park, Chiang Mai Province, Thailand. Kamimuria atra: Sivec & Stark, 2013:118. Examined material. 2 males (CAUC & HIST), China: Guangxi Zhuang Autonomous Region, Jinxiu County, Hekou Nature Reserve Management Station, 727 m, 24.1409 N, 110.1423 E, 2015.VII.19, leg. Xiumei Lu. Distribution. China (Guangxi); Thailand; Vietnam. Remarks. This species was originally known from Thailand, later reported from Vietnam (Sivec & Stark 2008; Stark & Sivec 2013). The dorsal and lateral outlines and armatures of the aedeagus in these males are identical to the original descriptions and illustrations (Figs. 1a–b). However, Sivec & Stark (2008) did not mention a dark sclerite (= ds) posterior to the dorsal armatures of the everted aedeagus present in these males (Figs. 1a, 1c).
description: Published as part of Li, Kefan, Wang, Bingli, Bozdoğan, Hakan & Li, Weihai, 2023, Additional records and poorly known species of Kamimuria Klapálek, 1907 (Plecoptera, Perlidae) from southern China, pp. 74-82 in Zootaxa 5346 (1) on pages 75-76, DOI: 10.11646/zootaxa.5346.1.4, http://zenodo.org/record/8353051
description: {"references": ["Sivec, I. & Stark, B. P. (2008) New species of Kamimuria Klapalek (Plecoptera: Perlidae) from Thailand and Vietnam, with notes on Chinese species. Illiesia, 4 (12), 110 - 138.", "Stark, B. P. & Sivec, I. (2013) Kamimuria gressitti, a new stonefly species from China (Plecoptera, Perlidae), and new records of K. atra from Vietnam. Illiesia, 9 (11), 116 - 121."]}
Shannon information entropy for a quantum nonlinear oscillator on a space of non-constant curvature
Creators: name: Ballesteros, Angel
name: Gutierrez-Sagredo, Ivan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mathematical Physics (math-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The so-called Darboux III oscillator is an exactly solvable $N$-dimensional nonlinear oscillator defined on a radially symmetric space with non-constant negative curvature. This oscillator can be interpreted as a smooth (super)integrable deformation of the usual $N$-dimensional harmonic oscillator in terms of a non-negative parameter $λ$ which is directly related to the curvature of the underlying space. In this paper, a detailed study of the Shannon information entropy for the quantum version of the Darboux III oscillator is presented, and the interplay between entropy and curvature is analysed. In particular, analytical results for the Shannon entropy in the position space can be found in the $N$-dimensional case, and the known results for the quantum states of the $N$-dimensional harmonic oscillator are recovered in the limit of vanishing curvature $λ\to 0$. However, the Fourier transform of the Darboux III wave functions cannot be computed in exact form, thus preventing the analytical study of the information entropy in momentum space. Nevertheless, we have computed the latter numerically both in the one and three-dimensional cases and we have found that by increasing the absolute value of the negative curvature (through a larger $λ$ parameter) the information entropy in position space increases, while in momentum space it becomes smaller. This result is indeed consistent with the spreading properties of the wave functions of this quantum nonlinear oscillator, which are explicitly shown. The sum of the entropies in position and momentum spaces has been also analysed in terms of the curvature: for all excited states such total entropy decreases with $λ$, but for the ground state the total entropy is minimised when $λ$ vanishes, and the corresponding uncertainty relation is always fulfilled.
description: 30 pages, 13 figures, 8 tables
Shadow, absorption and Hawking radiation of a Schwarzschild black hole surrounded by a cloud of strings in Rastall gravity
Creators: name: Li, Qian
name: Ma, Chen
name: Zhang, Yu
name: Lin, Zhi-Wen
name: Duan, Peng-Fei
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: This paper studies the black hole shadow, absorption cross section, and Hawking radiation of a massless scalar field in the background of a static spherically symmetric black hole spacetime that is surrounded by a cloud of strings in Rastall gravity. Specifically, the effects of the parameters $a$ and $β$ on the photon sphere and shadow radii are investigated. The results show that as the negative parameter $β$ decreases, the photon sphere and shadow radii change in an N-shape. In addition, the absorption cross section obtained after solving the massless Klein-Gordon equation is calculated using the sinc approximation and the partial waves method. We compare the absorption cross section obtained by the sinc approximation and the partial waves method, and find it to be exceptionally consistent in the mid-to-high frequency region. Furthermore, the effects of parameters $a$ and $β$ on absorption are examined in detail. Finally, we study in detail the effects of the parameters $a$, $β$ and $l$ on the Hawking radiation power emission spectrum of the considered black hole. It turns out that the string parameter $a$ always suppresses the power emission spectrum, indicating that such black holes live longer when the string parameter $a$ is increased while other parameters are fixed.
description: 27 pages, 10 figures, 1 Table
Quantitative analysis of valence photoemission spectra and quasiparticle excitations at chromophore-semiconductor interfaces
Creators: name: Patrick, Christopher E.
name: Giustino, Feliciano
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Investigating quasiparticle excitations of molecules on surfaces through photoemission spectroscopy forms a major part of nanotechnology research. Resolving spectral features at these interfaces requires a comprehensive theory of electron removal and addition processes in molecules and solids which captures the complex interplay of image charges, thermal effects and configurational disorder. We here develop such a theory and calculate the quasiparticle energy-level alignment and the valence photoemission spectrum for the prototype biomimetic solar cell interface between anatase TiO2 and the N3 chromophore. By directly matching our calculated photoemission spectrum to experimental data we clarify the atomistic origin of the chromophore peak at low binding energy. This case study sets a new standard in the interpretation of photoemission spectroscopy at complex chromophore/semiconductor interfaces.
description: 4 figures. Article published by in Phys. Rev. Lett. by the American Physical Society (2012)