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Constraining the dark matter density in galaxy clusters
(PoS, 2015)
We illustrate the potential of using stellar velocity dispersion profiles of brightest cluster galaxies
(BCGs), in combination with X-ray and weak-lensing derived cluster mass profiles, to constrain
the matter distribution ...
Comparing support vector machine and multinomial naive Bayes for named entity classification of South African languages
(PRASA, 2014)
In this study, two classical machine learning algorithms, multinomial naive Bayes and support vector machines, are compared when applied to named entity recognition for two South African languages, Afrikaans and English.
The ...
Aerosol properties over an urban site, Johannesburg measured from sunphotometer
(SASAS, 2014)
In this paper, we present results using ground based Sunphotometer (a passive
remote sensing instrument designed to study aerosol properties) as a part of NASA’s AERONET data. The analysis was based on the winter and ...
A Douglas-Shapiro-Shields factorization approach to the Leech equation
(MTNS, 2014)
In a recent series of papers concrete procedures
were derived to compute a stable rational matrix solution to the
Leech equation with rational matrix data. In one of these papers
the procedure involved a specific ...
Central stellar populations of brightest cluster galaxies
(South African Institute of Physics, 2014)
We analyse the stellar populations of a sample of brightest cluster galaxies (BCGs), for which high signal-to-noise ratio, long-slit spectra were obtained on the Gemini telescopes, by fitting their spectra using the software ...
The detailed nature of active central cluster galaxies
(South African Institute of Physics, 2014)
We present detailed IFU observations of the central few kiloparsecs of the ionised nebulae surrounding four active central cluster galaxies in cooling flow clusters. All four galaxies have Hα filaments, and existing data ...
Spatial and temporal assessment of atmospheric OC and BC concentrations at South African debits sites
(SASAS, 2014)
The baseline of uncertainty in aerosol radiative forcing is large and depends on aerosol
characteristics (e.g. size and composition), which can vary significantly on a regional scale.
Sources (natural, anthropogenic and ...
A search for optical counterparts of the complex Vela X system
(South African Institute of Physics, 2015)
The pulsar wind nebula (PWN) associated with the Vela pulsar is a bright source
in the radio, X-ray and gamma-ray bands, but not in the optical. This source is very near,
lying at a distance of 290 pc, as inferred from ...
The anatomy of γ-ray pulsar light curves
(South African Institute of Physics, 2014)
To obtain constraints on the inclination and observer angles, <i>α</i> and <i>ζ</i>, of a <i>γ</i>-ray pulsar from its observed light curve (LC), we make use of geometric models detailing the position and extent of emission ...
Empirical investigation of systems cost estimation models in the Limpopo Province of South Africa: a requirement modelling problem
(CSREA, 2014)
There are many factors believed to be important to systems development cost estimation. However an in-depth analysis demonstrates requirements as central cost drivers. The various transformations requirements go through ...