Diana Gonzalez and Joseph Umhoefer will spend 10 weeks this summer at Lawrence Berkeley National Lab (Applied Numerical Algorithms group). Their full funding comes from LBNL and from NSF, in particular from recently funded grant DMS-173814; supplement to DMS-1522734 (PI: Malgo Peszynska).
Dear Graduating Students, An MS or PHD defense is a public event, and should be advertised to all department members (and beyond). Those who are graduating should send the information about their defense to Graduate Coordinator (Stephanie Wise). We need at least to now day/time/location of the defense, title (and a brief abstract) of your paper, and name of your adviser. The happy event of your defense will be advertised on Department Calendar; we will also send reminders before the date.
Samantha Smith will be visiting the Institute for Advanced Study in Princeton from 15-26 May. She is participating in the 2017 Program for Women and Mathematics. This year's program focuses on Geometry and Randomness in Group Theory. https://www.math.ias.edu/wam/2017 .
Registration for Fall 2017 registration opens for graduate students Sunday, May 21st, and timely registration helps in the departmentâ€™s planning. Please discuss your plans with your adviser, and make a course plan for next year. (Course plans will be due to Graduate Coordinator by Friday Sep 29. ) Graduate Handbook provides guidelines on the recommended course loads. You can also consult the newly updated listing at http://www.math.oregonstate.edu/graduate-courses of graduate courses for next academic year. Fall schedule is essentially fixed, Winter assignments are in place but schedule is still tentative, while Spring schedule is to be determined. The initials of faculty assigned to teach those courses are provided. The information about the titles of topics courses as well as the updates on the schedule will be posted as they become available.
Graduate Committee would like to present a new addition to our website showcasing the research activity of graduate students. The page http://www.math.oregonstate.edu/graduate-publications provides a list of published or accepted articles in journals, proceedings, or book chapters whose authors are current graduate students or our graduate alumni. For alumni, it includes the publications on the work they did during their graduate study; we do not report here on their other achievements after graduation. The list was complied from archival information, with some recent additions and corrections. We ask students and faculty to send their corrections and additions to Stephanie Wise. Thank you very much for your contributions!
Min hash and bloom filters are two relatively new probabilistic techniques that seek to provide fast and low memory approximate answers to queries of extremely large data sets. In this talk, I will discuss some recent work with Hooman Zabeti in which we improve a probabilistic estimate of the Jaccard estimate when comparing similarity of very large sets (hundreds of millions to billions of elements) to sets of comparatively small size (tens of millions of elements). As an application, we demonstrate that this technique can be used to quickly identify the presence or absence (and relative abundance) of microbial organisms in a metagenomic sample.
I will assume no background in probabilistic data structures or "data sketches" for this talk, and it should be appropriate for a very general audience.
In this note, we generalize recent work of Mizuhara, Sellers, and Swisher that gives a method for establishing restricted plane partition congruences based on a bounded number of calculations. Using periodicity for partition functions, our extended technique could be a useful tool to prove congruences for certain types of combinatorial functions based on a bounded number of calculations. As applications of our result, we establish new and existing restricted plane partition congruences and several examples of restricted partition congruences. Also, we define a restricted form of plane overpartitions called k-rowed plane overpartitions as plane overpartitions with at most k rows. We derive the generating function for this type of partition and obtain a congruence modulo 4. Next, we engage a combinatorial technique to establish plane and restricted plane overpartition congruences modulo small powers of 2. For each even integer k, we prove a set of k-rowed plane overpartition congruences modulo 4. For odd integer k, we prove an equivalence relation modulo 4 between k-rowed plane overpartitions and unrestricted overpartitions.
As a consequence, using a result of Hirschhorn and Sellers, we obtain an infinite family of k-rowed plane overpartition congruences modulo 4 for each odd integer $k\geq 1$. Also, we obtain a few unrestricted plane overpartition congruences modulo 4. We establish and prove several restricted plane overpartition congruences modulo 8. Some examples of equivalences modulo 4 and 8 between plane overpartitions and overpartitions are obtained. In addition, we find and prove an infinite family of 5-rowed plane overpartition congruences modulo 8.
Ali's major professor is Prof. Holly Swisher.
We generalize overpartition rank and crank generating functions to obtain k-fold variants and give a combinatorial interpretation for each. The k-fold crank generating function is interpreted by extending the first and second residual cranks to a natural infinite family. The k-fold rank generating functions generate two families of buffered Frobenius representations, which generalize the first and second Frobenius representations studied by Lovejoy.
Thomas's major professor is Prof. Holly Swisher.
The goal of this paper is to solve and classify linear equations with octonionic coefficients and octonionic variables. While building up to the octonions we also classify linear equations over the quaternions and show how to relate the linear equations over the quaternions and octonions to matrices. We also construct a basis of linear equations that maps to the canonical basis of matrices for each space. Finally, we discuss automorphisms of the octonions, a subset of the linear equations.
Alex's major professor is Prof. Tevian Dray.
Abstract: Missing data is one of the major methodological problems in longitudinal studies. It not only reduces the sample size, but also can result in biased estimation and inference. It is crucial to correctly understand the missing mechanism and appropriately incorporate it into the estimation and inference procedures. Traditional methods, such as the complete case analysis and imputation methods, are designed to deal with missing data under unverifiable assumptions of MCAR and MAR. The purpose of this talk is to identify and estimate missing mechanism parameters under the non-ignorable missing assumption utilizing the refreshment sample. In particular, we propose a semi-parametric method to estimate the missing mechanism parameters by comparing the marginal density estimator using Hirano?s two constraints (Hirano et al. 1998) along with additional information from the refreshment sample. Asymptotic properties of semi-parametric estimators are developed. Inference based on bootstrapping is proposed and verified through simulations.