• Estimating the physical location of Twitter users with the von Mises-Fisher distribution (Mike Izbicki, UC Riverside)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    Approximately 500 million tweets are sent everyday.  Scientists monitor these tweets to predict the spread of disease, better allocate social welfare services, help first responders during natural disasters, and many other important tasks.  A key step in each of these tasks is estimating the location the tweet was sent from.  In this talk, I discuss how to combine machine […]

  • Community structure in networks: the effect of communities on a preferential attachment model and epidemic spreading (Emily Fischer, Cornell)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    Online social networks and other networks of interest are known to exhibit community structure, where a community is defined to be a highly interconnected group of nodes with possibly shared traits or features. However, classic network models, such as the preferential attachment model, do not account for community structure. In this talk, I will present […]

  • Applied Math Seminar: Measurement Error Modeling using Empirical Phase Functions (Prof. Cornelis Potgieter, Southern Methodist University)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    Measurement error, formally defined as the difference between the measured value and the true value of a quantity of interest, is ubiquitous. When a doctor takes your blood pressure, the instrumentation may not be properly calibrated and the reading is subject to error. When completing an online Harry Potter Sorting Hat quiz, you may accidentally […]

  • Applied Math Seminar: Eulerian Approaches based on the Level Set Method for Visualizing Continuous Dynamical Systems (Shingyu Leung, Department of Mathematics, HKUST)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    One very important concept in understanding a dynamical system is coherent structure. Such structure segments the domain into different regions with similar behavior according to a quantity. When we try to partition space-time into regions according to a Lagrangian quantity advected along with passive tracers, such class of coherent structure is called the Lagrangian coherent […]

  • Applied Math Seminar: Fluid mechanics at the microscale (Prof. Amy Buchmann, University of San Diego)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    I will present mathematical and computational methods used to model interactions between a viscous fluid and elastic structures in biological processes. For example, microfluidic devices carry very small volumes of liquid through channels and may be used to gain insight into many biological applications including drug delivery and development, but mixing and pumping at this […]

  • Applied Math Talk: Cluster analysis on covariance stationary ergodic processes and locally asymptotically self-similar processes (Nan Rao, CGU)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    We study the problems of clustering covariance stationary ergodic processes and locally asymptotically self-similar stochastic processes, when the true number of clusters is priorly known. A new covariance-based dissimilarity measure is introduced, from which efficient consistent clustering algorithms are obtained. As examples of application, clustering  fractional Brownian motions and clustering multifractional Brownian motions are respectively performed to illustrate the asymptotic consistency of […]

  • Models of Biological Tissue Electrostatics and Molecular Transport (Jim Sterling, KGI)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    In this presentation, some fundamentals of electrostatics in biology will be discussed with focus on the fact that most biological macromolecules including nucleic acids, carbohydrates, and proteins are negatively-charged. Electroneutrality […]

  • Applied Math Talk: Nonlocal problems for linear evolution equations (Prof. Smith David Andrew, Yale-NUS College, Singapore)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    Linear evolution equations, such as the heat equation, are commonly studied on finite spatial domains via initial-boundary value problems. In place of the boundary conditions, we consider “multipoint conditions”, where one specifies some linear combination of the solution and its derivative evaluated at internal points of the spatial domain, and “nonlocal” specification of the integral […]

  • Applied Math Seminar: The Kaczmarz Algorithm and its Applications to Data Science (Anna Ma, UCSD)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    Data is exploding at a faster rate than computer architectures can handle. For that reason, mathematical techniques to analyze large-scale data need be developed. Stochastic iterative algorithms have gained interest due to their low memory footprint and adaptability for large-scale data. In this talk, we will study the Randomized Kaczmarz algorithm for solving extremely large […]

  • Applied math seminar: Topological descriptions of protein folding (Helen Wong, CMC)

    Emmy Noether Room, Millikan 1021, Pomona College 610 N. College Ave., Claremont, California

    Knotting in proteins was once considered exceedingly rare.  However, systematic analyses of solved protein structures over the last two decades have demonstrated the existence of many deeply knotted proteins, and researchers now hypothesize that the knotting presents some functional or evolutionary advantage for those proteins.   Unfortunately, there is very little known (whether experimentally, through […]