Jiwen He

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Unprobì eme d'Optimisation liéà la Modélisation d'Aérosols Organiques. Abstract A mathematical model for the computation of the phase equilibrium related to atmospheric organic aerosols is proposed. The equilibrium is given by the minimum of the Gibbs free energy and is characterized using the notion of phase simplex of its convex hull. A primal-dual(More)
A model that rigorously computes the gas-particle partitioning and liquid-liquid equilibrium for organic atmospheric aerosol particles is presented. The dynamics of the mass transfers between the particle and the gas phase are modeled with differential equations and are coupled with a constrained optimization problem for the thermo-dynamic equilibrium(More)
  • Barbara Chapman, Hari Donepudi, Yupeng Li, Priya Raghunath, Yonghong Yan, Babu Sundaram +1 other
Air Quality Modelling is a recent important application that addresses several modern environmental health concerns. It requires considerable compute power to build, deploy and analyze the results of an air quality model and efforts to develop such applications can benefit from the availability of a computational grid. In this paper we discuss the needs of(More)
— We consider optimal matching of submanifolds such as curves and surfaces by a variational approach based on Hilbert spaces of diffeomorphic transformations. In an abstract setting, the optimal matching is formulated as a minimization problem involving actions of diffeomorphisms on regular Borel measures considered as supporting measures of the reference(More)
  • R Glowinski, J He, A Lozinski, M Picasso, J Rappaz, V Rezzonico +1 other
We present a new method [7] for numerically solving elliptic problems with multi-scale data using multiple levels of not necessarily nested grids. We use a relaxed iterative method which consists in calculating successive corrections to the solution in patches of finite elements. We analyse the spectral properties of the iteration operator [6]. We show how(More)
A mathematical model for the computation of chemical equilibrium of atmospheric inorganic aerosols is proposed. The equilibrium is given by the minimum of the Gibbs free energy for a system involving an aqueous phase, a gas phase and solid salts. A primal-dual method solving the Karush-Kuhn-Tucker conditions is detailed. An active set/Newton method permits(More)