Browsing Faculty of Natural Sciences by Title
Now showing items 1676-1695 of 2571
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On maximal inequalities via comparison principle
(SpringerOpen, 2015)Under certain conditions, we prove a new class of one-sided, weighted, maximal inequalities for a standard Brownian motion. Our method of proof is mainly based on a comparison principle for solutions of a system of ... -
On multiple classes of gamma-ray bursts, as deduced from autocorrelation functions or bivariate duration/hardness ratio distributions
(Oxford University Press, 2012)Autocorrelation functions (ACFs) of 119 gamma-ray bursts (GRBs) monitored by the Burst Alert Telescope (BAT) on Swift are calculated. Contrasting with previous results for smaller numbers of bursts from other missions, ... -
On multiple classes of gamma-ray bursts, as deduced from autocorrelation functions or bivariate duration/hardness ratio distributions
(Oxford University Press, 2012)Autocorrelation functions (ACFs) of 119 gamma-ray bursts (GRBs) monitored by the Burst Alert Telescope (BAT) on Swift are calculated. Contrasting with previous results for smaller numbers of bursts from other missions, ... -
On soft quasi-pseudometric spaces
(Elsevier, 2021)In this article, we introduce the concept of a soft quasi-pseudometric space. We show that every soft quasi-pseudometric induces a compatible quasi-pseudometric on the collection of all soft points of the absolute soft ... -
On the design of smart parking networks in the smart cities: an optimal sensor placement model
(MDPI, 2015)Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart ... -
On the Evolution Equation for Modelling the Covid-19 Pandemic
(2021)The paper introduces and discusses the evolution equation, and, based exclusively on this equation, considers random walk models for the time series available on the daily confirmed Covid-19 cases for different countries. ... -
On the exact constants in one-sided maximal inequalitiesfor Bessel processes
(Taylor and Francis Group, 2023)In this paper, we establish a one-sided maximal moment inequalitywith exact constants for Bessel processes. As a consequence, weobtain an exact constant in the Burkholder-Gundy inequality. Theproof of our main result is ... -
On the nature of the variable star UNSW-V-760
(Oxford University Press, 2011)The results of multicolour photometric monitoring over several nights of the probable X-ray source UNSW-V-760 are presented. Drawing on both present and past observations, it is shown that the star is multiperiodic and ... -
On the primordial origin of the smoothing excess in the Planck temperature power spectrum in light of LSS data
(IOP Publishing, 2022)The Planck DR3 measurements of the temperature and polarization anisotropies power spectra of the cosmic microwave background (CMB) show an excess of smoothing of the acoustic peaks with respect to ΛCDM, often quantified ... -
On the road to per cent accuracy - V. The non-linear power spectrum beyond ΛCDM with massive neutrinos and baryonic feedback
(Oxford University Press, 2021-12)In the context of forthcoming galaxy surveys, to ensure unbiased constraints on cosmology and gravity when using non-linear structure information, per cent-level accuracy is required when modelling the power spectrum. This ... -
On the time delay between ultra-relativistic particles
(Elsevier, 2016)The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through ... -
On the upper limit on stellar masses in the Large Magellanic Cloud cluster R136
(Oxford University Press, 2006)A truncated power-law distribution is fitted to the 29 largest stellar masses known in R136. Two different statistical techniques are used, with comparable results. An upper limit to the mass distribution of the order ... -
On the use of electrical resistivity methods in monitoring infiltration of salt fluxes in dry coal ash dumps in Mpumalanga, South Africa
(Water Research Commission, 2013)One of the principal environmental concerns relating to coal combustion waste disposal is the potential for groundwater contamination from salt fluxes and trace elements that may be leached into the underlying groundwater ... -
One- and Two-point source statistics from the LOFAR Two-metre sky survey first data release
(ESO, 2020)Context. The LOFAR Two-metre Sky Survey (LoTSS) will eventually map the complete Northern sky and provide an excellent opportunity to study the distribution and evolution of the large-scale structure of the Universe. Aims. ... -
One-pot synthesis and characterization of InP/ZnSe semiconductor nanocrystals
(Elsevier, 2013)We report on the one-pot synthesis of InP/ZnSe quantum dots (QDs) using a precursor-based colloidal synthesis in a noncoordinating solvent environment. The structural and optical studies were carried out on the as-prepared ... -
One-sided maximal inequalities for a randomly stopped bessel process
(Taylor & Francis Group, LLC, 2023)We prove a one-sided maximal inequality for a randomly stopped Bessel process of dimension (Formula presented.) For the special case when α = 1, we obtain a sharp Burkholder-Gundy inequality for Brownian motion as a ... -
The ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes again
(EDP Sciences, 2013)CONTEXT: R Coronae Borealis stars( RCBs) are rare, hydrogen-deficient, carbon rich super giant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars have been found ... -
An ontology for the south african protection of personal information act
(Curran Associates Inc., 2020)The protection and management of data, and especially personal information, is becoming an issue of critical importance in both the business environment and in general society. Various institutions have justifiable reasons ... -
Open user interconnect and quality of communication
(Telkom, 2004)We looked for and found two situations within the South African Digital Divide where constant and severe macro-scale latencies would most likely interfere with the usage of Information and Communication Technology (ICT) ... -
Opportunities for improving recognition of coastal wetlands in global ecosystem assessment frameworks
(Elsevier, 2021)Vegetated coastal wetlands, including seagrass, saltmarsh and mangroves, are threatened globally, yet the need to avert these losses is poorly recognized in international policy, such as in the Convention on Biological ...