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Now showing items 241-249 of 249
An efficient image encryption scheme based on fractal Tromino and Chebyshev polynomial
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Springer International Publishing
, 2021 , Article)
The security of digital content during transmission and storage through insecure communication links and databases is a challenging issue in today's world. In this article, an encryption scheme based on fractal Tromino and ...
Polycircular domains, numerical conformal mappings, and moduli of quadrilaterals
(
Springer Nature
, 2022 , Article)
We study numerical conformal mappings of planar Jordan domains with boundaries consisting of finitely many circular arcs, also called polycircular domains, and compute the moduli of quadrilaterals for these domains. ...
Turning point in COVID-19 severity and fatality during the pandemic: a national cohort study in Qatar
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BMJ Publishing Group
, 2023 , Article)
Objective To assess the evolution of COVID-19 severity and fatality in a unique setting that consistently applied, throughout the pandemic, rigorous and standardised criteria for defining severe COVID-19 outcomes.
Methods ...
Robust stabilization of LTI negative imaginary systems using the nearest negative imaginary controller
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John Wiley and Sons Inc
, 2023 , Article)
This paper considers the problem of robust stabilization of linear time-invariant systems with respect to unmodelled dynamics and structure uncertainties. To that end, a methodology to find the nearest negative imaginary ...
History of primary-series and booster vaccination and protection against Omicron reinfection
(
American Association for the Advancement of Science
, 2023 , Article)
Laboratory evidence suggests a possibility of immune imprinting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We investigated the differences in the incidence of SARS-CoV-2 reinfection in a ...
Prevalence of hepatitis B and C viruses among migrant workers in Qatar.
(
Springer Nature
, 2024 , Article)
Limited data exist on viral hepatitis among migrant populations. This study investigated the prevalence of current hepatitis B virus (HBV) infection and lifetime hepatitis C virus (HCV) infection among Qatar's migrant craft ...
Addressing bias in the definition of SARS-CoV-2 reinfection: implications for underestimation
(
Frontiers Media
, 2024 , Article)
Introduction: Reinfections are increasingly becoming a feature in the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, accurately defining reinfection poses methodological ...
Estimating protection afforded by prior infection in preventing reinfection: Applying the test-negative study design.
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Oxford University Press
, 2023 , Article)
The COVID-19 pandemic has highlighted the need to use infection testing databases to rapidly estimate effectiveness of prior infection in preventing reinfection ($P{E}_S$) by novel SARS-CoV-2 variants. Mathematical modeling ...
Effectiveness of two and three doses of COVID-19 mRNA vaccines against infection, symptoms, and severity in the pre-omicron era: A time-dependent gradient
(
Elsevier
, 2024 , Article)
BackgroundVaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and ...