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Description:: RIVET computes degree-Rips bifiltrations, a two-parameter version of the Vietoris Rips complex that takes the density of points into account. In a Rips complex, a simplex appears when all of its faces appear. When computing single parameter persistent homology, we can simply take the maximum time of appearance of its faces to be the time of appe...
Creator:: Zhao, Roy (University of California, Berkeley)
Created:: 2018-08-15
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2019-02-04

Description:: I will talk about the random periodic solutions of random dynamical systems generated by stochastic differential equations and stochastic partial differential equations. I will start with definition and motivations of studying a random periodic solution, and discuss its connection with periodic measure. I will demonstrate that to find a random p...
Creator:: Zhao, Huaizhong (Loughborough University)
Created:: 2012-10-25
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: We present a direct imaging algorithm for both the location and geometry of extended targets. Our algorithm is based on a physical factorization of the response matrix of an active array. A resolution and noise level based thresholding is used for regularization. Our algorithm is extremely simple and efficient since no forward solver or iteratio...
Creator:: Zhao, Hongkai (University of California, Irvine)
Created:: 2005-10-20
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: We develop computational and experimental methods to gain insights into visual functions and psychiatric disorders. We also build deep learning models that predict human behaviors and identify people with disorders. In this talk, I will share our recent innovations on data and models, aiming at understanding and predicting visual attention in na...
Creator:: Zhao, Catherine Qi (University of Minnesota, Twin Cities)
Created:: 2017-02-03
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: This paper presents a novel nonlinear framework for the construction of flexible multivariate dependence structure~(i.e., copula) from existing copulas based on a straightforward "pairwise max" rule. The newly constructed max-copula has a closed form and has strong interpretability. Compared to the classical "linear symmetric" mixture copula, th...
Creator:: Zhang, Zhengjun (University of Wisconsin, Madison)
Created:: 2018-02-21
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2019-02-04

Description:: We first give a brief overview of American option pricing models and numerical methods. We treat American option models as a special class of obstacle problems. Finite element formulation is introduced together with error analysis of numerical solutions. Some interesting properties about sensitivity of the option price to the payoff function are...
Creator:: Zhang, Yongmin (NONE)
Created:: 2009-02-27
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: Studies on the break-up of a liquid drop or an air bubble reveal that the dynamics prior to a singularity can have several forms, ranging from universal, with no memory of the initial state, or integrable, which has a complete memory. We find that how an air bubble disconnects from an underwater nozzle is associated with an unusually rich class ...
Creator:: Zhang, Wendy W. (University of Chicago)
Created:: 2008-07-18
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: In single particle reconstruction (SPR) from cryo-electron microscopy (EM), the 3D structure of a molecule needs to be determined from its 2D projection images taken at unknown viewing directions. Zvi Kam showed already in 1980 that the autocorrelation function of the 3D molecule over the rotation group SO(3) can be estimated from 2D projection ...
Creator:: Zhang, Teng (University of Central Florida)
Created:: 2016-11-15
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: In this talk we will discuss low-complexity algorithms for solving large-scale convex optimization problems. Such algorithms include: gradient projection, proximal gradient, Iterative Shrinkage-Thresholding (ISTA), Nesterov's acceleration, and Alternating Direction Method of Multipliers (ADMM). The emphasis of the discussion will be placed on th...
Creator:: Zhang, Shuzhong (University of Minnesota, Twin Cities)
Created:: 2016-08-01
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19

Description:: In this talk we will introduce conic optimization models, in particular second-order cone programming (SOCP) and semidefinite programming (SDP). We will discuss various applications of these new optimization models. Conic duality theory will be introduced as well. Finally we will introduce the so-called central path following method for solving ...
Creator:: Zhang, Shuzhong (University of Minnesota, Twin Cities)
Created:: 2016-08-03
Contributed By:: University of Minnesota, Institute for Mathematics and its Applications.
Last Updated:: 2018-06-19