Wed, February 26, 2020
Public Access Category: All |
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- Time:
- 11:30am
- Location:
- Ramanujan Hall, Department of Mathematics
- Description:
- Statistics and Probability seminar.
Speaker: Nilanjan Chatterjee.
Affiliation: Johns Hopkins University.
Date and Time: Wednesday 26 February, 11:30 am - 12:30 pm.
Venue: Ramanujan Hall, Department of Mathematics.
Title: Statistical model building using data fusion.
Abstract: Many applications require development of complex statistical
models involving many variables. It may not, however, be possible to train
such model in a single dataset of adequately large sample size that has
measured all the variables. Instead, data may be available across multiple
studies, where any individual study may not measure all the variables, but
the different studies altogether cover all the variables. In this talk, I
will describe how to fit popular non-linear models, such as logistic
regression models, by combining information from such multiple disparate
data sources. In fact we will show it is possible to fit such models only
using "summary-level" information, i.e. estimates of parameters from
fitted simpler models, from individual studies and thus overcoming some
of the logistical and ethical issues related to sharing of individual
level data across studies. Methods will be illustrated through extensive
simulation studies and real data examples
- Time:
- 2:30pm-3:30pm
- Location:
- Ramanujan Hall, Department of Mathematics
- Description:
- Geometry and Topology seminar.
Speaker: Arjun Paul.
Affiliation: IIT Bombay.
Date and Time: Wednesday 26 February, 02:30 pm - 03:30 pm.
Venue: Ramanujan Hall, Department of Mathematics.
Title: Fundamental group schemes of Hilbert scheme of n points on
irreducible smooth projective varieties of dimension 1 and 2.
Abstract: : Let k be an algebraically closed field of characteristic p > 3. Let X be an irreducible
smooth projective k-variety of dimension d ∈ {1, 2} over k. Fix an integer n ≥ 2, and let
Hilbn
X be the Hilbert scheme parametrizing effective 0-cycles of length n on X. In this talk
we discuss on the S-fundamental group scheme and Nori’s fundamental group scheme of
Hilbn
X. This is a joint work with Ronnie Sebastian.
- Time:
- 4:00pm-5:00pm
- Location:
- Ramanujan Hall, Department of Mathematics
- Description:
- Mathematics Colloquium.
Speaker: Nilanjan Chatterjee.
Affiliation: Johns Hopkins University.
Date and Time: Wednesday 26 February, 04:00 pm - 05:00 pm.
Venue: Ramanujan Hall, Department of Mathematics.
Title: Disease risk prediction and causal inference using genome-wide
genetic data.
Abstract: Recent genome-wide association studies have led to
identification of thousands of genetic variants associated with complex
traits and diseases like adult height, body mass index, heart disease,
type-2 diabetes and cancer. The large scale genetic data, some of which
are publicly available, provide statisticians, mathematicians, computer
scientists and other quantitative researchers an incredible opportunity
for the development and applications of novel methods and algorithms. In
this talk, I will describe the work from our laboratory to harness the
power of these big datasets to address two most pressing problems in
public health research. In particular, I will describe simple and more
advanced machine learning methods for building genetic risk-scores from
these datasets that can be used to predict prospectively individuals' risk
of diseases. Further, I will describe how genetic data can be used to
conduct, "instrumental" variable analysis, an approach popular in
Economics, to understand causal relationship among risk-factors and health
outcomes.