Qingfang Wu

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We present a method for assimilating Lagrangian sensor measurement data into a shallow water equation model. The underlying estimation problem (in which the dynamics of the system are represented by a system of partial differential equations) relies on the formulation of a minimisation of an error functional, which represents the mismatch between the(More)
— We present a state estimation method for two-dimensional shallow water equations in rivers using Lagrangian drifter positions as measurements. The aim of this method is to compensate for the lack of knowledge of upstream and downstream boundary conditions in rivers that causes inaccuracy in the velocity field estimation by releasing drifters equipped with(More)
This article presents a method to estimate flow variables for an open channel network governed by the linearized Saint-Venant equations and subject to periodic forcing. The discharge at the upstream end of the system and the stage at the downstream end of the system are defined as the model inputs; the flow properties at selected internal locations, as well(More)
INTRODUCTION To understand better the risk of tuberculosis transmission with increasing delay in tuberculosis treatment, we undertook a retrospective cohort study in Shenzhen, China. METHODS All pulmonary tuberculosis cases in the Shenzhen tuberculosis surveillance database from 1993-2010 were included. Sputum smear positivity and presence of pulmonary(More)
— An inverse modeling problem for systems governed by first-order, hyperbolic partial differential equations subject to periodic forcing is investigated. The problem is described as a PDE constrained optimization problem with the objective of minimizing the norm of the difference between the observed inputs and the model outputs. After linearizing and(More)
— In this article, we investigate real-time estimation of flow states, average velocity and stage (water depth), in open channels using the measurements obtained from Lagrangian sensors (drifters). One-dimensional Shallow Water Equations (SWE), also known as Saint-Venant equations, are used as the mathematical model for the flow. After linearizing and(More)
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