cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Open source software for simulations and inversions of airborne electromagnetic data
Creators: name: Heagy, Lindsey J.
name: Kang, Seogi
name: Cockett, Rowan
name: Oldenburg, Douglas
Publisher: name: arXiv
Year: 2019
Subjects: subject: Geophysics (physics.geo-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Inversions of airborne EM data are often an iterative process, not only requiring that the researcher be able to explore the impact of changing components such as the choice of regularization functional or model parameterization, but also often requiring that forward simulations be run and fields and fluxes visualized in order to build an understanding of the physical processes governing what we observe in the data. In the hope of facilitating this exploration and promoting reproducibility of geophysical simulations and inversions, we have developed the open source software package, SimPEG. The software has been designed to be modular and extensible with the goal of allowing researchers to interrogate all of the components and to facilitate the exploration of new inversion strategies. We present an overview of the software in its application to airborne EM and demonstrate its use for visualizing fields and fluxes in a forward simulation as well as its flexibility in formulating and solving the inverse problem. We invert a line of airborne TDEM data over a conductive vertical plate using a 1D voxel-inversion, a 2D voxel inversion and a parametric inversion, where all of the forward modelling is done on a 3D grid. The results in this paper can be reproduced by using the provided Jupyter notebooks. The Python software can also be modified to allow users to experiment with parameters and explore the physics of the electromagnetics and intricacies of inversion.
Novel metal-insulator-transition at the SrTiO3/SmTiO3 interface
Creators: name: Ahadi, Kaveh
name: Stemmera, Susanne
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on a metal-insulator transition (MIT) that is observed in an electron system at the SmTiO3/SrTiO3 interface. This MIT is characterized by an abrupt transition at a critical temperature, below which the resistance changes by more than an order of magnitude. The temperature of the transition systematically depends on the carrier density, which is tuned from ~ 1x10^14 cm^-2 to 3x10^14 cm^-2 by changing the SmTiO3 thickness. Analysis of the transport properties shows non-Fermi liquid behavior and mass enhancement as the carrier density is lowered. We compare the MIT characteristics with those of known MITs in other materials systems and show that they are distinctly different in several aspects. We tentatively conclude that both long range Coulomb interactions and the fixed charge at the polar interface are likely to play a role in this MIT. The strong dependence on the carrier density makes this MIT of interest for field-tunable devices.
description: Accepted for publication In Phys. Rev. Lett
"It's part of what makes me.": women's constructions of 'anorexia nervosa' in their identity journeys over ten years
Creators: name: Conti, Janet Elizabeth
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: This dissertation is interested in women’s voices and some of the ways they negotiate their identities in relation to the discursively constructed category of ‘anorexia nervosa’. Nine women who came to identify their experiences as ‘anorexia nervosa’ were interviewed three times over ten years. This sample of women was drawn from an initial sample of 21 women and therefore the 12 women who did not participate in the interviews ten years later where not included in the substantive analysis. The research interviews sought to provide a context for these women to speak on their own terms; terms not confined to the discursive field of ‘anorexia nervosa’. A critical discursive analysis of the women’s interviews identified some of the ways these women used, and were positioned by, the discursive resources available to them at the time. ‘Anorexia nervosa’ was found to be a troubled socially constructed category. In particular, it positioned the sum of their lives as disordered and dominated by illness. The discourse assumed that the person should regain a pre-morbid state in the form of a recovery. Within the discursive context of talk not confined to ‘anorexia’ talk, the women were active in refashioning alternative positions. Speaking on their own terms and through use of image and metaphor to author a complex social reality, they reconstructed their lived experiences as an identity journey where they connected with what they valued, which had strong implications for their lives as presently lived. The implications of this research are significant given that the majority of research to date confines the terms of speaking to the ‘anorexia’ discourse.
Thermodynamic Effects of Single-Qubit Operations in Silicon-Based Quantum Computing
Creators: name: Lougovski, Pavel
name: Peters, Nicholas A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Silicon-based quantum logic is a promising technology to implement universal quantum computing. It is widely believed that a millikelvin cryogenic environment will be necessary to accommodate silicon-based qubits. This prompts a question of the ultimate scalability of the technology due to finite cooling capacity of refrigeration systems. In this work, we answer this question by studying energy dissipation due to interactions between nuclear spin impurities and qubit control pulses. We demonstrate that this interaction constrains the sustainable number of single-qubit operations per second for a given cooling capacity. Our results indicate that a state-of-the-art dilution refrigerator can, in principle, accommodate operations on millions of qubits before thermal energy dissipation becomes a problem.
Transient X-ray Sources in the Magellanic-type Galaxy NGC 4449
Creators: name: Jithesh, V.
name: Wang, Zhongxiang
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the identification of seven transient X-ray sources in the nearby Magellanic-type galaxy NGC 4449 using the archival multi-epoch X-ray observations conducted with {\it Chandra}, {\it XMM-Newton} and {\it Swift} telescopes over year 2001--2013. Among them, two sources are classified as supersoft X-ray sources (SSSs) because of their soft X-ray color and rest of the sources are X-ray binaries (XRBs). Transient SSSs spectra can be fitted with a blackbody of effective temperature $\sim 80-105$ eV and luminosities were $\simeq 10^{37} - 10^{38} {\rm~erg\ s}^{-1}$ in 0.3--8 keV. These properties are consistent with the widely accepted model for SSSs, an accreting white dwarf with the steady nuclear burning on its surface, while the SSS emission has also been observed in many post-nova systems. Detailed analysis of one sufficiently bright SSS revealed the strong short-term variability, possibly showing a 2.3 hour periodic modulation, and long-term variability, detectable over 23 years with different X-ray telescopes before year 2003. The X-ray properties of four other transients are consistent with neutron star or black hole binaries in their hard state, while the remaining source is most likely an XRB with a quasi-soft X-ray spectrum. Analysis of archival {\it Hubble Space Telescope} image data was also conducted, and multiple massive stars were found as possible counterparts. We conclude that the X-ray transient properties in NGC 4449 are similar to those in other Magellanic-type galaxies.
description: Accepted for publication in ApJ, 10 Pages, 4 Tables, 3 Figures
3D electromagnetic modelling and inversion: A case for open-source
Creators: name: Oldenburg, Douglas W.
name: Heagy, Lindsey J.
name: Kang, Seogi
name: Cockett, Rowan
Publisher: name: arXiv
Year: 2019
Subjects: subject: Geophysics (physics.geo-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Electromagnetics has an important role to play in solving the next generation of geoscience problems. These problems are multidisciplinary, complex, and require collaboration. This is especially true at the base scientific level where the underlying physical equations need to be solved, and data, associated with physical experiments, need to be inverted. In this paper, we present arguments for adopting an open-source methodology for geophysics and provide some background about open-source software for electromagnetics. Immediate benefits are the reduced time required to carry out research, being able to collaborate, having reproducible results, and being able to disseminate results quickly. To illustrate the use of an open-source methodology in electromagnetics, we present two challenges. The first is to simulate data from a time domain airborne system over a conductive plate buried in a more resistive earth. The second is to jointly invert airborne TDEM and FDEM data with ground TDEM. SimPEG, Simulation and Parameter Estimation in Geophysics, (https://simpeg.xyz) is used for the open-source software. The figures in this paper can be reproduced by downloading the Jupyter Notebooks we provide with this paper (https://github.com/simpeg-research/oldenburg-2018-AEM). Access to the source code allows the researcher to explore the simulations and inversions by changing model and inversion parameters, plot fields and fluxes to gain further insight about the EM phenomena, and solve a new research problem by using open-source software as a base. By providing results in a manner that allows others to reproduce, further explore, and even extend them, we hope to demonstrate that an open-source paradigm has the potential to enable more rapid progress of the geophysics community as a whole.
Doubly commuting invariant subspaces for representations of product systems of $C^*$-correspondences
Creators: name: Trivedi, Harsh
name: Veerabathiran, Shankar
Publisher: name: arXiv
Year: 2019
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46L08, 47A13, 47A15, 47B38, 47L30, 47L55, 47L80

description: We obtain a Shimorin-Wold-type decomposition for a doubly commuting covariant representation of a product system of $C^*$-correspondences. This extends a recent Wold-type decomposition by Jeu and Pinto for a $q$-doubly commuting isometries. Application to the wandering subspaces of doubly commuting induced representations is explored, and a version of Mandrekar's Beurling type theorem is obtained to study doubly commuting invariant subspaces using Fock space approach due to Popescu.
description: 26pages, revised version
Mesoporous carbon nitride based nanomaterials for solar fuel production
Creators: name: Kheradmand, Amanj
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: From economic and environmental aspects, the generation of hydrogen (H2) from renewable solar energy and water through photocatalytic water splitting is a promising route, but the development of an efficient catalyst remains a great challenge for its technological use on a large scale. Because of several features like being metal-free, nontoxic, low cost, and chemically stable, carbon nitride has attracted worldwide attention. Compared to bulk carbon nitride, mesoporous carbon nitride (MCN) possesses a higher surface area and plentiful accessible mesopores. For the first time, Co3O4/MCN nanocomposites were designed and synthesised for photocatalytic H2 evolution in this work. Co3O4,earth-abundant nanoparticles, were supported on MCN via an impregnation method. Complementary characterisation techniques were employed to understand the properties of the fabricated catalysts.The bare MCN prepared under optimum conditions showed high photocatalytic activity under visible light irradiation without using any co-catalyst. The Co3O4/MCN with a Co3O4 mass content of 5 wt% exhibited the optimum photocatalytic activity in H2 evolution, which was two times higher than that of the bare MCN. The improved photocatalytic performance may be attributed to the enhanced catalytic properties, visible-light harvesting and effective charge separation.
Error bounds for the normal approximation to the length of a Ewens partition
Creators: name: Tsukuda, Koji
Publisher: name: arXiv
Year: 2019
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: Let $K(=K_{n,θ})$ be a positive integer-valued random variable whose distribution is given by ${\rm P}(K = x) = \bar{s}(n,x) θ^x/(θ)_n$ $(x=1,\ldots,n) $, where $θ$ is a positive number, $n$ is a positive integer, $(θ)_n=θ(θ+1)\cdots(θ+n-1)$ and $\bar{s}(n,x)$ is the coefficient of $θ^x$ in $(θ)_n$ for $x=1,\ldots,n$. This formula describes the distribution of the length of a Ewens partition, which is a standard model of random partitions. As $n$ tends to infinity, $K$ asymptotically follows a normal distribution. Moreover, as $n$ and $θ$ simultaneously tend to infinity, if $n^2/θ\to\infty$, $K$ also asymptotically follows a normal distribution. In this paper, error bounds for the normal approximation are provided. The result shows that the decay rate of the error changes due to asymptotic regimes.
description: 18 pages
Worker Functional Abilities, Occupational Requirements, and Job Accommodations: A Close Look at Three Occupations
Creators: name: Henly, Megan
name: Brucker, Debra L.
name: Houtenville, Andrew J.
Publisher: name: My University
Year: 2021
Subjects: subject: functional assessment, occupational requirements, workplace accommodations
subject: Population and Demography
subject: Social Sciences

description: This report examines the occupational requirements, physical and mental functioning, and use of accommodations among workers in three key occupations: cashiers, receptionists, and those in nursing fields. These jobs are among the top occupations represented in the work histories of federal disability claimants in the United States (U.S.). We collected survey data from 802 people working in these occupations. The survey collected demographic information, work-related characteristics (including the use of workplace accommodations), and functional assessment information using the self-reported functional assessment using the Work Disability Functional Assessment Battery (WD-FAB). The WD-FAB generates eight scores per respondent, one for each of eight dimensions related to physical function (basic mobility, fine motor function, upper body function, and community mobility) and mental function (resilience and sociability, mood and emotions, self-regulation, and cognition and communication). Results indicated that accommodation use is associated with lower functioning in this population of employed or recently employed adults. In addition, for each occupation, we compared the WD-FAB scores to data from the Occupational Requirements Survey (ORS) using measures that align with these WD-FAB domains. This comparison demonstrates the extent to which functioning in these dimensions is necessary and suggests opportunities for task-specific, occupation-specific accommodations. We discuss implications for disability determination according to SSA guidelines.
Cutoff on Graphs and the Sarnak-Xue Density of Eigenvalues
Creators: name: Golubev, Konstantin
name: Kamber, Amitay
Publisher: name: arXiv
Year: 2019
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C81

description: It was recently shown by Lubetzky and Peres (2016) and by Sardari (2018) that Ramanujan graphs, i.e., graphs with the optimal spectrum, exhibit cutoff of the simple random walk in an optimal time and have an optimal almost-diameter. We show that this spectral condition can be replaced by a weaker condition, the Sarnak-Xue density property, to deduce similar results. This allows us to prove that some natural families of Schreier graphs of the $SL_2(\mathbb{F}_t)$-action on the projective line exhibit cutoff, thus proving a special case of a conjecture of Rivin and Sardari.
description: 27 pages. v2- many minor corrections
Evaluation of countering violent extremism initiatives: lessons learned from best practice public health frameworks
Creators: name: Scott-Smith, Stephanie
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: The importance of the empirical evaluation of Countering Violent Extremism (CVE) programs to ensure continued refinement and transparency is widely recognised throughout the literature. However there is much debate regarding how evaluation is best conducted, and a limited body of evidence to draw from. The current research project has developed out of this area of debate in the scholarly literature; the broader argument suggests that approaches to CVE would benefit from using a public health framework, which may enable the allocation of additional resources and funding, facilitate information sharing, encourage trust from the community, and align with existing public health approaches to complex issues, such as violence prevention. A school of thought stemming from this debate posits that the frameworks of practice and theory within public health are relevant to CVE, one of which is the framework of program evaluation. This thesis seeks to critically analyse this debate by focusing on the application of public health evaluation to CVE projects in two ways; firstly, public health evaluation frameworks will be described and critically analysed. Secondly, three CVE case studies from Australia will be used to explore the potential utility of evaluation methodology already utilised in public health. This study found that the principles of public health evaluation best practice are applicable to CVE programs and add value to CVE evaluation. Findings suggest that applying existing public health evaluation approaches could ensure that several of the challenges identified with CVE evaluation are resolved. In addition, application of these approaches would ensure a consistent and internationally recognised evaluation language is used, that evaluation is imbedded in CVE program development, and that there is accountability for using and disseminating the lessons learned from CVE evaluations. It is hoped that future CVE project evaluation strategies may be informed by the lessons learned in the current study.
Disk masses around solar-mass stars are underestimated by CO observations
Creators: name: Yu, Mo
name: Evans, Neal J.
name: Dodson-Robinson, Sarah E.
name: Willacy, Karen
name: Turner, Neal J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Gas in protostellar disks provides the raw material for giant planet formation and controls the dynamics of the planetesimal-building dust grains. Accurate gas mass measurements help map the observed properties of planet-forming disks onto the formation environments of known exoplanets. Rare isotopologues of carbon monoxide (CO) have been used as gas mass tracers for disks in the Lupus star-forming region, with an assumed interstellar CO/H$_2$ abundance ratio. Unfortunately, observations of T-Tauri disks show that CO abundance is not interstellar---a finding reproduced by models that show CO abundance decreasing both with distance from the star and as a function of time. Here we present radiative transfer simulations that assess the accuracy of CO-based disk mass measurements. We find that the combination of CO chemical depletion in the outer disk and optically thick emission from the inner disk leads observers to underestimate gas mass by more than an order of magnitude if they use the standard assumptions of interstellar CO/H$_2$ ratio and optically thin emission. Furthermore, CO abundance changes on million-year timescales, introducing an age/mass degeneracy into observations. To reach factor of a few accuracy for CO-based disk mass measurements, we suggest that observers and modelers adopt the following strategies: (1) select the low-$J$ transitions; (2) observe multiple CO isotopologues and use either intensity ratios or normalized line profiles to diagnose CO chemical depletion; and (3) use spatially resolved observations to measure the CO abundance distribution.
description: 22 pages, 16 figures, Accepted for publication in ApJ
Transformation of Traditional Silvo-Pastoral Home-Gardens: A Case Study in Southern Sri Lanka
Creators: name: Zoysa, Mangala De
name: Zoysa, Mangala De
Publisher: name: Unknown
Year: 2018
Subjects: subject: Environmental Economics and Policy
subject: silvo-pastoral system
subject: traditional home-gardens
subject: ecosystem changes
subject: economic trade-offs
subject: social breakthroughs

description: The Pasture Development Program on silvo-pastoral system in traditional home-gardens in Matara district was commenced with the aim of increasing milk production and income of the small-scale cattle farmers. The objectives of the study were to analyze ecosystem changes, economic trade-offs and social breakthroughs taken place in home-gardens after the program, with the aim of expanding the program coverage. The study was conducted through a field survey interviewing 34 farmers randomly selected from the participants. Tthe farmers have changed the composition of eco-systems in their home-gardens, replaced traditional grasses with CO3 fodder, and removed number of trees disturbing fodder cultivation. They have significantly lost some traditionally cultivated crops and trees due to competition with fodder during dry seasons. The farmers have significantly increased the milk yield per cow, market surplus and income, increased the amount of fodder sufficient to feed their cattle and little market surplus, and gradually adapted to cow-done as organic fertilizer. The social breakthroughs are identified as: reduced risk of conflicts with neighbors and theft of cattle, controlled damages caused by cattle to agricultural crops, reduced time spent on feeding cattle during dry seasons, increased domestic milk consumption, and increased the number of milk collecting centers induced by increased milk production. Although the Pasture Development Program have transformed the traditional home-gardens to improved silvo-pastoral system, community governance yet to be developed in order attract externalities particularly land use planning, technology development and policy support.
title: Στρατηγικό μάνατζμεντ ανθρωπίνων πόρων - Strategic Human Resource Management (SHRM) στο σύγχρονο επιχειρηματικό περιβάλλον: μελέτη περίπτωσης εταιρείας
title: Strategic Human Resource Management (SHRM) in the contemporary business environment: case study
titleType: AlternativeTitle
Creators: name: Κοτσομύτη, Τριανταφυλένα
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2022
Subjects: subject: Στρατηγικό μάνατζμεντ
subject: Διοίκηση ανθρωπίνων πόρων
subject: Στρατηγικό μάνατζμεντ ανθρωπίνων πόρων
subject: Ανταγωνιστικό πλεονέκτημα

description: Το σύγχρονο επιχειρηματικό περιβάλλον χαρακτηρίζεται από συνεχόμενες και γρήγορες αλλαγές. Οι επιχειρήσεις για να μπορούν να επιβιώνουν και να ευημερούν χρειάζεται να είναι σε θέση να προσαρμόζονται συνεχώς σε αυτές τις αλλαγές, αλλά και πολλές φορές να τις δημιουργούν. Αυτό το επιτυγχάνουν μέσα από την αποτελεσματική χρήση των πόρων τους ώστε να μπορούν να επιτυγχάνουν ανταγωνιστικό πλεονέκτημα. Για τη μακροπρόθεσμη επιβίωση του οργανισμού το ανταγωνιστικό πλεονέκτημα πρέπει να είναι διατηρήσιμο. Οι επιχειρήσεις σήμερα συνειδητοποιούν ολοένα και περισσότερο τον κρίσιμο ρόλο του ανθρώπινου δυναμικού τους στην απόκτηση διατηρήσιμου ανταγωνιστικού πλεονεκτήματος, μέσα από το Στρατηγικό Μάνατζμεντ Ανθρωπίνων Πόρων. Κύριος στόχος της παρούσας διπλωματικής εργασίας είναι η εξέταση των θεωριών που έχουν αναπτυχθεί αναφορικά με το Στρατηγικό Μάνατζμεντ Ανθρωπίνων Πόρων και δευτερευόντως πώς αυτό εφαρμόζεται μέσω μελέτης περίπτωσης εταιρείας που δίνει μεγάλη βαρύτητα στο ανθρώπινο δυναμικό της. Αρχικά παρατίθενται οι βασικές αρχές του Στρατηγικού Μάνατζμεντ, στη συνέχεια οι βασικές θεωρίες της Διοίκησης Ανθρωπίνων Πόρων και στη συνέχεια η ανάλυση των θεωριών του Στρατηγικού Μάνατζμεντ Ανθρωπίνων Πόρων. Ακολούθως, αναλύεται ο σχεδιασμός και η δόμηση συστημάτων HRM, η ανάπτυξη ανθρώπινου δυναμικού καθώς και τα σύγχρονα θέματα του HRM. Στο προτελευταίο κεφάλαιο αναφέρεται η μεθοδολογία που ακολουθήθηκε και στο τελευταίο κεφάλαιο μελετάται η περίπτωση της ναυτιλιακής εταιρείας GasLog Ltd. Αρχικά γίνεται αναφορά σε ιστορικά στοιχεία της εταιρείας, στο όραμα, στην αποστολή και στις αξίες της, στους στόχους, στην εταιρική διακυβέρνηση, στην εταιρική κοινωνική υπευθυνότητα και στις στρατηγικές που ακολουθεί. Στη συνέχεια αναλύεται η δομή και κουλτούρα της και επισημαίνονται οι πρακτικές ανθρωπίνου δυναμικού που έχει υιοθετήσει. Τέλος αναλύεται η διάσταση του SHRM και πώς το ανθρώπινο δυναμικό της ευθυγραμμίζεται με τη στρατηγική της εταιρείας Στο τέλος παρατίθεται SWOT ανάλυση και προτεινόμενη στρατηγική.
On super Plücker embedding and cluster algebras
Creators: name: Shemyakova, Ekaterina
name: Voronov, Theodore
Publisher: name: arXiv
Year: 2019
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We define a super analog of the classical Plücker embedding of the Grassmannian into a projective space. One of the difficulties of the problem is rooted in the fact that super exterior powers $Λ^{r|s}(V)$ are not a simple generalization from the completely even case (this works only for $r|0$ when it is possible to use $Λ^r(V)$). To construct the embedding we need to non-trivially combine a super vector space $V$ and its parity-reversion $ΠV$. Our "super Plücker map" takes the Grassmann supermanifold $G_{r|s}(V)$ to a "weighted projective space" $P\left(Λ^{r|s}(V)\oplus Λ^{s|r}(ΠV)\right)$ with weights $+1,-1$. A simpler map $G_{r|0}(V)\to P(Λ^r(V))$ works for the case $s=0$. We construct a super analog of Plücker coordinates, prove that our map is an embedding, and obtain "super Plücker relations". We analyze another type of relations (due to Khudaverdian) and show their equivalence with the super Plücker relations for $r|s=2|0$. We discuss application to much sought-after super cluster algebras and construct a super cluster structure for $G_2(\mathbb{R}^{4|1})$ and $G_2(\mathbb{R}^{5|1})$.
description: LaTeX, 49 pp. Exposition reworked and streamlined. (No change to the previous version; metadata corrected.)
Large time behavior of solutions to 3-D MHD system with initial data near equilibrium
Creators: name: Deng, Wen
name: Zhang, Ping
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q30, 76D03

description: In \cite{ChCa}, Califano and Chiuderi conjectured that the energy of incompressible Magnetic hydrodynamical system is dissipated at a rate that is independent of the ohmic resistivity. The goal of this paper is to mathematically justify this conjecture in three space dimension provided that the initial magnetic field and velocity is a small perturbation of the equilibrium state $(e_3,0).$ In particular, we prove that for such data, 3-D incompressible MHD system without magnetic diffusion has a unique global solution. Furthermore, the velocity field and the difference between the magnetic field and $e_3$ decay to zero in both $L^\infty$ and $L^2$ norms with explicit rates. We point out that the decay rate in the $L^2$ norm is optimal in sense that this rate coincides with that of the linear system. The main idea of the proof is to exploit H$\ddot{o}$rmander's version of Nash-Moser iteration scheme, which is very much motivated by the seminar papers \cite{Kl80, Kl82, Kl84} by Klainerman on the long time behavior to the evolution equations.
Behavioral an real-time verification of a pipeline in the COSMA environment
Creators: name: Mieścicki, Jerzy
name: Daszczuk, Wiktor B.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences
subject: B.1.4
subject: 68M14

description: The case study analyzed in the paper illustrates the example of model checking in the COSMA environment. The system itself is a three-stage pipeline consisting of mutually concurrent modules which also compete for a shared resource. System components are specified in terms of Concurrent State Machines (CSM) The paper shows verification of behavioral properties, model reduction technique, analysis of counter-example and checking of real time properties.
description: 12 pages, 7 figures
LYTNet: A Convolutional Neural Network for Real-Time Pedestrian Traffic Lights and Zebra Crossing Recognition for the Visually Impaired
Creators: name: Yu, Samuel
name: Lee, Heon
name: Kim, John
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Currently, the visually impaired rely on either a sighted human, guide dog, or white cane to safely navigate. However, the training of guide dogs is extremely expensive, and canes cannot provide essential information regarding the color of traffic lights and direction of crosswalks. In this paper, we propose a deep learning based solution that provides information regarding the traffic light mode and the position of the zebra crossing. Previous solutions that utilize machine learning only provide one piece of information and are mostly binary: only detecting red or green lights. The proposed convolutional neural network, LYTNet, is designed for comprehensiveness, accuracy, and computational efficiency. LYTNet delivers both of the two most important pieces of information for the visually impaired to cross the road. We provide five classes of pedestrian traffic lights rather than the commonly seen three or four, and a direction vector representing the midline of the zebra crossing that is converted from the 2D image plane to real-world positions. We created our own dataset of pedestrian traffic lights containing over 5000 photos taken at hundreds of intersections in Shanghai. The experiments carried out achieve a classification accuracy of 94%, average angle error of 6.35 degrees, with a frame rate of 20 frames per second when testing the network on an iPhone 7 with additional post-processing steps.
description: 12 pages, 5 figures, 6 tables, International Conference on Computer Analysis of Images and Patterns (CAIP)
PEnBayes: A Multi-Layered Ensemble Approach for Learning Bayesian Network Structure from Big Data
Creators: name: Tang, Yan
name: Wang, Jianwu
name: Nguyen, Mai
name: Altintas, Ilkay
Publisher: name: MDPI
Year: 2019
Subjects: UMBC Big Data Analytics Lab

description: Discovering the Bayesian network (BN) structure from big datasets containing rich causal relationships is becoming increasingly valuable for modeling and reasoning under uncertainties in many areas with big data gathered from sensors due to high volume and fast veracity. Most of the current BN structure learning algorithms have shortcomings facing big data. First, learning a BN structure from the entire big dataset is an expensive task which often ends in failure due to memory constraints. Second, it is quite difficult to select a learner from numerous BN structure learning algorithms to consistently achieve good learning accuracy. Lastly, there is a lack of an intelligent method that merges separately learned BN structures into a well structured BN network. To address these shortcomings, we introduce a novel parallel learning approach called PEnBayes (Parallel Ensemble-based Bayesian network learning). PEnBayes starts with an adaptive data preprocessing phase that calculates the Appropriate Learning Size and intelligently divides a big dataset for fast distributed local structure learning. Then, PEnBayes learns a collection of local BN Structures in parallel using a two-layered weighted adjacent matrix-based structure ensemble method. Lastly, PEnBayes merges the local BN Structures into a global network structure using the structure ensemble method at the global layer. For the experiment, we generate big data sets by simulating sensor data from patient monitoring, transportation, and disease diagnosis domains. The Experimental results show that PEnBayes achieves a significantly improved execution performance with more consistent and stable results compared with three baseline learning algorithms.
Compiled generics for functional programming languages
Creators: name: Roberts, Matthew
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: "We address the problem of extending existing functional language compilers to support generic programming constructs, such as those that arise in term rewriting and datatype generic programs. In particular, we present a compiler capable of compiling a wide range of generic programs in a way which substantially reduces the execution overhead traditionally associated with such programs, without requiring type classes. We explicitly build upon a baseline functional compiler by extending it to support a universal spine view of data and by adding a mechanism for building polymorphic functions from monomorphic ones. This work employs variants of standard pattern compilation and lambda lifting translations that render these generic extensions into efficient code while making only modest modifications to our baseline compiler and its run-time. We show that type inference (with annotations for higher-ranked types and polymorphic recursion) can be maintained, by building all the mechanisms needed for type inference of generic programs on top of an existing variant of Damas and Milner's algorithm W. We demonstrate that this compiler achieves type safe and efficient compiled generic programs by showing the breadth of generic programs that we can encode with it and by benchmarking the execution speed and memory use of the programs output by the compiler. The generic programs we demonstrate are generic transformations, generic queries, generic traversals, generic equality, generic show plus a large number of variants of these. We also provide a proof of the soundness of the type system which underpins the compiler. In summary, the primary outcome of this research is a new compiler for generic programs which uses a unique combination of encoding techniques and which generates efficient generic code. For each of our extensions (polymorphic functions with specific behaviour and the explicit spine view) we provide new algorithms for pattern compilation, type inference and conversion to primitive operations. These can be easily incorporated into existing functional language compilers.
Feedback arcs and node hierarchy in directed networks
Creators: name: Zhao, Jin-Hua
name: Zhou, Hai-Jun
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Directed networks such as gene regulation networks and neural networks are connected by arcs (directed links). The nodes in a directed network are often strongly interwound by a huge number of directed cycles, which lead to complex information-processing dynamics in the network and make it highly challenging to infer the intrinsic direction of information flow. In this theoretical paper, based on the principle of minimum-feedback, we explore the node hierarchy of directed networks and distinguish feedforward and feedback arcs. Nearly optimal node hierarchy solutions, which minimize the number of feedback arcs from lower-level nodes to higher-level nodes, are constructed by belief-propagation and simulated-annealing methods. For real-world networks, we quantify the extent of feedback scarcity by comparison with the ensemble of direction-randomized networks and identify the most important feedback arcs. Our methods are also useful for visualizing directed networks.
description: 18 pages (main text and appendices, including 9 figures). This paper is related to and is an expansion of our previous post arXiv:1605.09257
Thick morphisms of supermanifolds, quantum mechanics, and spinor representation
Creators: name: Khudaverdian, Hovhannes
name: Voronov, Theodore
Publisher: name: arXiv
Year: 2019
Subjects: subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: Quantum Algebra (math.QA)
subject: Representation Theory (math.RT)
subject: Symplectic Geometry (math.SG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: "Thick" or "microformal" morphisms of supermanifolds generalize ordinary maps. They were discovered as a tool for homotopy algebras. Namely, the corresponding pullbacks provide $L_{\infty}$-morphisms for $S_{\infty}$ or Batalin--Vilkovisky algebras. It was clear from the start that constructions used for thick morphisms closely resemble some fundamental notions in quantum mechanics and their classical limits (such as action, Schrödinger and Hamilton--Jacobi equations, etc.) There was also a natural question about any connection of thick morphisms with spinor representation. We answer both questions here. We establish relations of thick morphisms with fundamental concepts of quantum mechanics. We also show that in the linear setup quantum thick morphisms with quadratic action give (a version of) the spinor representation for a certain category of canonical linear relations, which is an analog of the Berezin--Neretin representation and a generalization of the metaplectic representation (and ordinary spinor representation).
description: 19 pp. LaTeX
Revealing physical activity of GRB central engine with macronova/kilonova data
Creators: name: Shen, Zhao-Qiang
name: Jin, Zhi-Ping
name: Liang, Yun-Feng
name: Li, Xiang
name: Fan, Yi-Zhong
name: Wei, Da-Ming
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The modeling of Li-Paczyński macronova/kilonova signals gives reasonable estimate on the neutron-rich material ejected during the neutron star mergers. Usually the accretion disk is more massive than the macronova ejecta, with which the efficiencies of converting the disk mass into prompt emission of three merger-driven GRBs can hence be directly constrained. Supposing the macronovae/kilonovae associated with GRB 050709, GRB 060614 and GRB 130603B arose from radioactive decay of the r-process material, the upper limit on energy conversion efficiencies are found to be as low as $\sim 10^{-6}-10^{-4}$. Moreover, for all three events, neutrino annihilation is likely powerful enough to account for the brief gamma-ray flashes. Neutrino annihilation can also explain the "extended" emission lasting $\sim 100$ s in GRB 050709, but does not work for the one in GRB 060614. These progresses demonstrate that the macronova can serve as a novel probe of the central engine activity.
description: 5 pages, 2 figures. Accepted for publication in ApJL
The representation of nouns in the mental lexicon: evidence from brain-impaired and normal speakers
Creators: name: Fieder, Nora
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: "This thesis investigates the lexical representation of mass (e.g., rice, milk) and count nouns (e.g., chair, cat) in language production. The research presented focuses on how mass/count (countability) information is processed at the lexical syntactic and conceptual-semantic levels. Chapter 1 reviews and discusses previous research with language unimpaired and impaired speakers and its theoretical implications for the representation of countability information in language production and comprehension. Results support the assumption that nouns have lexical-syntactic specification for countability. Chapter 2 investigates processing of mass and count nouns and their determiners during noun phrase production with language unimpaired speakers in two picture-word interference experiments. Results showed countability congruency effects which indicate that mass/count information is represented at the level of lexical-syntax and that mass/count specific determiners compete for selection. Chapter 3 and 4 present single case studies (one in Chapter 3 and two in Chapter 4) which examine possible selective impairments of mass noun lexical-syntax in three aphasic individuals with grammatical impairment. These investigations provide further evidence for the lexical-syntactic representation of mass/count information. A series of mass/count specific tasks was used to systematically investigate countability processing in language production and comprehension. Two of the individuals, RAP (Chapter 3) and DEH (Chapter 4), were found to suffer from a lexical-syntactic impairment which affected processing of mass noun grammar and led to frequent substitutions of mass noun determiners by count noun determiners. The third case study describes (Chapter 4) the individual GEC, whose conceptual semantic impairment affected naming of mass nouns. Results of the case studies not only provide further evidence that nouns and determiners are specified for countability at the level of lexical-syntax but also reveal that this lexical-syntactic information can be influenced by conceptual-semantic information which is activated by visual properties of the stimuli. The research presented in this thesis provides evidence that nouns are lexical-syntactically specified for mass and count and that activation of this information is required for the selection of countablity congruent determiners. Results show further that activation of mass and count nouns and their determiners can be influenced by conceptual-semantic information." -- Abstract.
VICS82: the VISTA-CFHT Stripe 82 near-infrared survey
Creators: name: Geach, J. E.
name: Lin, Y-T.
name: Makler, M.
name: Kneib, J-P.
name: Ross, N. P.
name: Wang, W-H.
name: Hsieh, B-C.
name: Leauthaud, A.
name: Bundy, K.
name: McCracken, H. J.
name: Comparat, J.
name: Caminha, G. B.
name: Hudelot, P.
name: Lin, L.
name: Van Waerbeke, L.
name: Pereira, M. E. S.
name: Mast, D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the VISTA-CFHT Stripe 82 (VICS82) survey: a near-infrared (J+Ks) survey covering 150 square degrees of the Sloan Digital Sky Survey (SDSS) equatorial Stripe 82 to an average depth of J=21.9 AB mag and Ks=21.4 AB mag (80% completeness limits; 5-sigma point source depths are approximately 0.5 mag brighter). VICS82 contributes to the growing legacy of multi-wavelength data in the Stripe 82 footprint. The addition of near-infrared photometry to the existing SDSS Stripe 82 coadd ugriz photometry reduces the scatter in stellar mass estimates to delta log(M_stellar)~0.3 dex for galaxies with M_stellar>10^9M_sun at z~0.5, and offers improvement compared to optical-only estimates out to z~1, with stellar masses constrained within a factor of approximately 2.5. When combined with other multi-wavelength imaging of the Stripe, including moderate-to-deep ultraviolet (GALEX), optical and mid-infrared (Spitzer IRAC) coverage, as well as tens of thousands of spectroscopic redshifts, VICS82 gives access to approximately 0.5 Gpc^3 of comoving volume. Some of the main science drivers of VICS82 include (a) measuring the stellar mass function of L^star galaxies out to z~1; (b) detecting intermediate redshift quasars at 2
description: Accepted for publication in ApJS. Data at http://stri-cluster.herts.ac.uk/vics82
MPEC 2024-D137 : 2015 DX248
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Balancing stimulus and goal-driven attentional demands: investigating the role of gamma oscillations in human early visual cortex using magnetoencephalography
Creators: name: Koelewijn, Loes
Publisher: name: Macquarie University
Year: 2022
Subjects: Other education not elsewhere classified

description: "Salient events tend to capture our attention. When such events are irrelevant to something we are looking for they need to be inhibited not to distract us. Efficient allocation of attention involves balancing of attentional demands driven by both salient events and current goals. To deal with the constantly changing visual input in light of attentional goals, it is crucial that visual brain areas participate in this balancing. The aim of this thesis is to investigate the role of early visual areas in the balancing of stimulus and goal-driven attentional demands. I primarily focus on the synchronisation of oscillatory activity in the gamma band, because its role in both neural communication and visual processing makes it a prime candidate for mediating the dynamic balancing of attentional demands. In Chapter 1 I review the literature on behavioural effects and neural processing of attentional demands. In Chapter 2, I focus on how evoked responses in early visual cortex are modulated when stimulus salience and behavioural relevance compete for attentional allocation. I then address how these factors interact to modulate gamma activity in three steps. In Chapter 3, I use a strong gamma-inducing stimulus to investigate how orientation, a stimulus property strongly represented in early visual cortex, affects the gamma response. In Chapter 4, I investigate how directing voluntary attention towards or away from that optimal stimulus affects the gamma response it induces. Finally, I address how stimulus and goal-driven factors combine to influence the gamma response when they compete for attentional allocation in Chapter 5. The main findings in this thesis are that stimulus and goal-driven factors influence gamma synchronisation in early visual cortex at different frequencies, and interact to modulate the gamma response when attentional demands are actively balanced. These findings contribute to our understanding of the role of early visual cortex in both low-level and attentional visual processing. I address the implications of these findings in Chapter 6." -- Abstract.