120 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- North-West UniversityZA8 papers
- National Institute for Theoretical PhysicsZA5 papers
- University of Cape TownZA4 papers
- University of KwaZulu-NatalZA4 papers
- University of California, BerkeleyUS3 papers
- Carnegie Mellon UniversityUS2 papers
- Northumbria UniversityGB2 papers
- University of GlasgowGB2 papers
- University of the Western CapeZA2 papers
- Aberystwyth UniversityGB1 paper
- Austrian Academy of SciencesAT1 paper
- Bay Area Environmental Research InstituteUS1 paper
21 papers
Existence domains of arbitrary amplitude nonlinear structures in two-electron temperature space plasmas. II. High-frequency electron-acoustic solitons
S. K. Maharaj, R. Bharuthram, S. V. Singh +1
A three-component plasma model composed of ions, cool electrons, and hot electrons is adopted to investigate the existence of large amplitude electron-acoustic solitons not only fo…
Impact of Batch Normalization on Convolutional Network Representations
Hermanus L. Potgieter, Coenraad Mouton, Marelie H. Davel
Batch normalization (BatchNorm) is a popular layer normalization technique used when training deep neural networks. It has been shown to enhance the training speed and accuracy of…
Spectroscopic Imaging of the Sun with MeerKAT: Opening a New Frontier in Solar Physics
Devojyoti Kansabanik, Surajit Mondal, Divya Oberoi +7
Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging th…
The Missing Margin: How Sample Corruption Affects Distance to the Boundary in ANNs
Marthinus W. Theunissen, Coenraad Mouton, Marelie H. Davel
Classification margins are commonly used to estimate the generalization ability of machine learning models. We present an empirical study of these margins in artificial neural netw…
The radial variation of the solar wind turbulence spectra near the kinetic break scale from Parker Solar Probe measurements
S. Lotz, A. E. Nel, R. T. Wicks +7
In this study we examine the radial dependence of the inertial and dissipation range indices, as well as the spectral break separating the inertial and dissipation range in power d…
Adaptations to a geomagnetic field interpolation method in Southern Africa
M. J. Heyns, S. I. Lotz, P. J. Cilliers +1
Space weather and its impact on infrastructure presents a clear risk in the modern era, as evidenced by the adverse effects of geomagnetically induced currents (GICs) in power netw…
Exploring layerwise decision making in DNNs
Coenraad Mouton, Marelie H. Davel
While deep neural networks (DNNs) have become a standard architecture for many machine learning tasks, their internal decision-making process and general interpretability is still…
On the Turbulent Reduction of Drifts for Solar Energetic Particles
J. P. van den Berg, N. E. Engelbrecht, N. Wijsen +1
Particle drifts perpendicular to the background magnetic field have been proposed by some authors as an explanation for the very efficient perpendicular transport of solar energeti…
The updated SANAE neutron monitor
R. D. Strauss, C. van der Merwe, C. Diedericks +5
Neutron monitors have been the premier ground-based instruments for monitoring the near-Earth cosmic ray flux for more than 70 years. It is essential to continue with such measurem…
A Primer on Focused Solar Energetic Particle Transport: Basic physics and recent modelling results
J. P. van den Berg, R. D. Strauss, F. Effenberger
The basics of focused transport as applied to solar energetic particles are reviewed, paying special attention to areas of common misconception. The micro-physics of charged partic…
Patch Size Evolution During Pulsating Aurora
N. Partamies, K. Bolmgren, E. Heino +3
We report both decreasing and increasing trends in the patch sizes during pulsating aurora events. About 150 pulsating auroral events over the Fennoscandian Lapland have been succe…
The Array of Long Baseline Antennas for Taking Radio Observations from the Sub-Antarctic
H. C. Chiang, T. Dyson, E. Egan +11
Measurements of redshifted 21-cm emission of neutral hydrogen at <30 MHz have the potential to probe the cosmic "dark ages," a period of the universe's history that remains unobser…
Probabilistic Analysis of Power Network Susceptibility to GICs
M. J. Heyns, S. I. Lotz, C. T. Gaunt
As reliance on power networks has increased over the last century, the risk of damage from geomagnetically induced currents (GICs) has become a concern to utilities. The current st…
Data Driven Transfer Functions and Transmission Network Parameters for GIC Modelling
M. J. Heyns, C. T. Gaunt, S. I. Lotz +1
Typical geomagnetically induced current (GIC) modelling assumes the induced quasi-DC current at a node in the transmission network is linearly related to the local geoelectric fiel…
Frequency Components of Geomagnetically Induced Currents for Power System Modelling
D. T. O. Oyedokun, M. J. Heyns, P. J. Cilliers +1
Geomagnetically induced currents (GICs) in power systems are conventionally modelled as direct currents, based on their commonly described quasi-DC nature. For more representative…
The Source Regions of Whistlers
Dávid Koronczay, János Lichtenberger, Mark A. Clilverd +7
We present a new method for identifying the source regions of lightning generated whistlers observed at a fixed location. In addition to the spatial distribution of causative light…
Global diagnostics of ionospheric absorption during X-ray solar flares based on 8-20MHz noise measured by over-the-horizon radars
O. I. Berngardt, J. M. Ruohoniemi, J. -P. St-Maurice +9
An analysis of noise attenuation during eighty solar flares between 2013 and 2017 was carried out at frequencies 8-20 MHz using thirty-four SuperDARN radars and the EKB ISTP SB RAS…
Probing Radio Intensity at high-Z from Marion: 2017 Instrument
L. Philip, Z. Abdurashidova, H. C. Chiang +11
We introduce Probing Radio Intensity at high-Z from Marion (PRIZM), a new experiment designed to measure the globally averaged sky brightness, including the expected redshifted 21…
Modified Korteweg-de Vries solitons at supercritical densities in two-electron temperature plasmas
Frank Verheest, Carel P. Olivier, Willy A. Hereman
The supercritical composition of a plasma model with cold positive ions in the presence of a two-temperature electron population is investigated, initially by a reductive perturbat…
SunPy - Python for Solar Physics
The SunPy Community, Stuart J Mumford, Steven Christe +19
This paper presents SunPy (version 0.5), a community-developed Python package for solar physics. Python, a free, cross-platform, general-purpose, high-level programming language, h…
CorPITA: An Automated Algorithm for the Identification and Analysis of Coronal "EIT Waves"
David M. Long, D. Shaun Bloomfield, Peter T. Gallagher +1
The continuous stream of data available from the Atmospheric Imaging Assembly (AIA) telescopes onboard the Solar Dynamics Observatory (SDO) spacecraft has allowed a deeper understa…