In this paper, we propose a fiber-optic time synchronization technique based on the bidirectional wavelength division multiplexing (WDM) transmission over a fiber link.The effect of fiber dispersion on the uncertainty of the system is effectively suppressed by properly allocating the forward and backward wavelength maps.Thus, only an initial easy-t
With countries across the world facing repeated epidemic waves, it becomes critical to monitor, mitigate and prevent subsequent waves.Common indicators like active case numbers may not be sensitive enough in the presence of systemic inefficiencies like insufficient testing or contact tracing.Test positivity rates are sensitive to testing strategies
Background Hand, foot, and mouth disease (HFMD) is a serious threat among children in China.Some studies have found that air pollution is associated with HFMD incidence, but the results showed heterogeneity.In this study, we aimed to explore the heterogeneity of associations between air pollutants and the number of HFMD cases and to identify signif