Browsing Research Articles (Statistics & Population Studies) by Title
Now showing items 24-43 of 162
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The detailed forms of the LMC Cepheid PL and PLC relations
(Oxford University Press, 2007)Possible deviations from linearity of the Large Magellanic Cloud Cepheid period–luminosity (PL) and period–luminosity–colour (PLC) relations are investigated. Two data sets are studied, respectively from the Optical ... -
Detection of an increasing orbital period in the subdwarf B eclipsing system NSVS 14256825
(Oxford University Press, 2012)New timings of eclipses made in 2010 and 2011 are presented for the hot subdwarf B (sdB) eclipsing binary NSVS 14256825. Composed of an sdB star and a much cooler companion, with a period near 0.1104 days, this system ... -
A detection threshold in the amplitude spectra calculated from Kepler data obtained during K2 mission.
(Oxford University Press, 2015)We present our analysis of simulated data in order to derive a detection threshold which can be used in the pre-whitening process of amplitude spectra. In case of ground-based data of pulsating stars, this threshold is ... -
Determinants of women’s preferred and actual abortion provision locations in Nigeri
(Springer, 2021)Background: Unsafe abortion remains a leading cause of maternal mortality globally. Many factors can infuence women’s decisions around where to seek abortion care; however, little research has been done on abortion care ... -
Does seasonality and stochastic cycles affect output growth in Nigeria? Lessons for development planning
(International Foundation for Research and Development (IFRD), 2016)This paper examines the seasonality and stochastic cycle associated with GDP growth in Nigeria using two measures of filter. Our findings include, that the Christiano & Fitzgerald (2003) filter removed low-periodicity ... -
The effect of weak lensing on distance estimates from supernovae
(American Astronomical Society, 2013)Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line of sight. We find ... -
Epidemiological analysis of spatially misaligned data: a case of highly pathogenic avian influenza virus outbreak in Nigeria
(Cambridge University Press, 2013)This research is focused on the epidemiological analysis of the transmission of the highly pathogenic avian influenza (HPAI) H5N1 virus outbreak in Nigeria. The data included 145 outbreaks together with the locations of ... -
Epidemiology, clinical characteristics and severity of gradual onset injuries in recreational road cyclists: A cross-sectional study in 21,824 cyclists - SAFER XIII
(Elsevier, 2020)Objectives: Prevalence, clinical characteristics and severity of gradual onset injuries (GOIs) in cyclists are poorly documented. We determine the prevalence, anatomical regions/sites affected and severity of GOIs among ... -
Estimation of the coherence time of stochastic oscillations from modest samples
(Oxford University Press, 2012)‘Quasi-periodic’ or ‘solar-like’ oscillations can be described by three parameters – a characteristic frequency, a coherence time (or ‘quality factor’) and the variance of the random driving process. This paper is concerned ... -
Evidence for rapid evolution of periodic variations in an ultracool dwarf
(Oxford University Press, 2006)The results of three short photometric monitoring runs on the L0 dwarf 2MASS J06050196−2342270, during three consecutive nights, are presented. The observations show the persistent presence of a 2.4-h period, with an IC ... -
Examining inequality of opportunity in the use of maternal and reproductive health interventions in Sierra Leone
(Oxford University Press, 2020)Poor countries, such as Sierra Leone, often have poor health outcomes, whereby the majority of the population cannot access lifesaving health services. Access to, and use of, maternal and reproductive health services is ... -
An exploratory look at associated factors of poverty on educational attainment in Africa and in-depth multilevel modelling for Namibia.
(BER, 2013)This study examines several indicator variables related to education and poverty in Africa from the Demographic and Health Surveys (DHS). Many have described income and education as one of the fundamental determinants ... -
An extensive search for rapid optical variability in ultracool dwarfs
(Oxford University Press, 2013)In this paper, a summary of optical time-series photometry of 125 ultracool dwarfs is given. The observing strategy was to monitor each object continuously for 2–3 h in order to ascertain whether itwas rapidly variable. ... -
Factors affecting the enrolment rate of students in Higher Education Institutions in the Gauteng province, South Africa
(SAGE, 2018)The purpose of this research is to investigate and analyse higher education institutions' enrolment and drop-out rates within the Gauteng province, South Africa. Large-scale secondary data from the General Household ... -
Factors associated with antiretroviral treatment failure among people living with HIV on antiretroviral therapy in resource- poor settings: a systematic review and metaanalysis
(BMC, 2020)Background: Despite the increase in the number of people accessing antiretroviral therapy (ART), there is limited data regarding treatment failure and its related factors among HIV-positive individuals enrolled in HIV care ... -
Factors associated with mothers’ health care‑seeking behaviours for childhood fever in Burkina Faso: Findings from repeated cross‑sectional household surveys
(BMC, 2022)Fever is one of the most frequent reasons for paediatric consultations in Burkina Faso, but health careseeking behaviours and the factors associated with health care-seeking in the event of childhood fever are poorly documented. ... -
Factors associated with patellofemoral pain in recreational road cyclists: A cross-sectional study in 59953 cyclists – SAFER XXXIII
(Elsevier, 2023)Patellofemoral pain (PFP) is a common cycling-related injury, and independent factors need to be identified to enable effective injury prevention strategies. We aim to determine factors associated with PFP in cyclists ... -
Fitting power-law distributions to data with measurement errors
(Oxford University Press, 2009)If X, which follows a power-law distribution, is observed subject to Gaussian measurement error e, thenX+e is distributed as the convolution of the power-lawand Gaussian distributions. Maximum-likelihood estimation of ... -
Fitting sinusoids to observations of rotating spotted stars
(Oxford University Press, 2007)It is assumed that K blocks (e.g. seasons) of observations are available, and the parameters characterizing a fixed-frequency sinusoidal variability (mean light level, amplitude, phase) are constant within each of the ... -
The “four sigma” limit for significant periodicities
(Springer Verlag, 2010)Most of the pulsations which have been observed in sdB stars have very low amplitudes. Detection of modes from photometric observations is usually performed by noting the most prominent peaks in a periodogram or, ...