Browsing Research Articles (Statistics & Population Studies) by Title
Now showing items 85-104 of 162
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Mental health services in Ethiopia: emerging public health
(WB Saunders, 2011)Summary: Objectives: Examine the mental health issues in Ethiopia in relation to services offered in this direction. Study Design: Retrospective. Methods: Results of the 2005 Ethiopian Demographic and Health Survey and ... -
A mixed-methods study exploring women’s perceptions of terminology surrounding fertility and menstrual regulation in Côte d’Ivoire and Nigeria
(BMC, 2021)Women use various terms when discussing the management of their fertility and menstrual irregularities and may interpret the experience of ending a possible pregnancy in nuanced ways, especially when their pregnancy status ... -
Modelling the rotation period distribution of M dwarfs in the Kepler field
(Springer Verlag, 2018)McQuillan et al. (Mon. Not. R. Astron. Soc.432:1203, 2013) presented 1570 periods P of M dwarf stars in the field of view of the Kepler telescope. It is expected that most of these reflect rotation periods, due to starspots. ... -
More on the nature of the variable star UNSW-V-760
(Oxford University Press, 2012)The results of two multicolour time-series photometric observing runs, separated by about two months, are presented. The same periodicities previously detected in photometry of UNSWV- 760 are still present, albeit at ... -
Multi-year trend analysis of childhood immunization uptake and coverage in Nigeria
(Cambridge University Press, 2013)As a leading indicator of child health, under-five mortality was incorporated in the United Nations Millennium Development Goals with the aim of reducing the rate by two-thirds between 1990 and 2015. Under-five mortality in ... -
Multicolour time series photometry of 2MASS 1207−3932
(Oxford University Press, 2008)Time series photometry in VRI of the young brown dwarf Two-Micron All-Sky Survey (2MASS) J1207334−393254 is presented. Variability in I is insignificant, but amplitudes up to ∼0.2 mag in R, and ∼0.55 mag in V, are seen ... -
Multicolour time series photometry of four short-period weak-lined T Tauri stars
(Oxford University Press, 2015)The paper describes continuous photometric monitoring of four pre-main-sequence stars, probable members of young stellar associations. Measurements, covering at least four nights per star, were obtained by cycling through ... -
Multicolour time series photometry of the T Tauri star CVSO 30
(Oxford University Press, 2015)Five consecutive runs of at least five hours, and two shorter runs, of V(RI)C time series photometry of CVSO 30 are presented. No evidence could be seen for planetary transits, previously claimed in the literature for ... -
Multicolour time series photometry of the variable star 1SWASP J234401.81−212229.1
(Oxford University Press, 2014)1SWASP J234401.81-212229.1 may be one of a handful of contact binaries comprising two Mdwarfs. Modelling of the available observations is complicated by the fact that the radiation of the eclipsing system is dominated ... -
Multicolour time series photometry of three periodic ultracool dwarfs
(Oxford University Press, 2013)Photometry in I, or contemporaneously in I and R, of the known variable ultracool dwarfs Kelu-1 and 2MASS J11553952−3727350 is presented. The nature of the variability of Kelu-1 appears to evolve on time-scales of a day ... -
Multifilter time-series observations of three short period ATLAS variable stars
(Oxford University Press, 2019-09)The ‘Asteroid Terrestrial-impact Last Alert System’ discovered hundreds of thousands of new candidate variable stars. Follow-up observations of three of these are reported in this paper. The targets were selected on the ... -
Multiple imputation of unordered categorical missing data: A comparison of the multivariate normal imputation and multiple imputation by chained equations
(Brazilian Statistical Association, 2016). Missing data are common in survey data sets. Enrolled subjects do not often have data recorded for all variables of interest. The inappropriate handling of them may negatively affect the inferences drawn. Therefore, special ... -
Multiple regression of GRB luminosity on light-curve properties
(Oxford University Press, 2009)Statistical relations between the luminosity L of gamma-ray burster (GRBs) and several of their other observable properties have been discovered. Four of these properties are considered here: the spectral lag; a measure ... -
Multivariate comparisons of the period–light-curve shape distributions of Cepheids in five galaxies
(Oxford University Press, 2007)A number of published tests suitable for the comparison of multivariate distributions are described. The results of a small power study, based on realistic Cepheid log period – Fourier coefficient data, are presented. ... -
Near-infrared time-series photometry of six fields in the young open cluster IC 2391
(Oxford University Press, 2006)Fields containing targets of spectral types later than M5 were monitored in JHKs for about 7 h each. None of the targets showed variability at levels exceeding 0.02 (or smaller, in some cases). Seven new variable stars ... -
The Nyquist frequency for irregularly spaced time-series: a calculation formula
(Oxford University Press, 2006)Eyer & Bartholdi showed that the Nyquist frequency of irregularly sampled time-series can be very high. In this paper, a calculation formula for the Nyquist frequency is presented. In practice there is an upper limit of ... -
The Nyquist frequency for time series with slight deviations from regular spacing
(Oxford University Press, 2009)The paper is based on the notion that the Nyquist frequency νN is a symmetry point of the periodogram of a time series: the power spectrum at frequencies above νN is a mirror image of that below νN. Koen showed that the ... -
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 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 ...