Difference between revisions of "SIAM Student Chapter Seminar"

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__NOTOC__
 
__NOTOC__
  
 
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*'''When:''' Most Friday at 11:30am
 
 
*'''When:''' Every Other Wednesday at 2:15 pm (except as otherwise indicated)
 
 
*'''Where:''' 901 Van Vleck Hall
 
*'''Where:''' 901 Van Vleck Hall
*'''Organizers:''' [http://www.math.wisc.edu/~ke/ Ke Chen]  
+
*'''Organizers:''' [http://www.math.wisc.edu/~xshen/ Xiao Shen]
*'''To join the SIAM Chapter mailing list:''' email [join-siam-chapter@lists.wisc.edu] website.
+
*'''Faculty advisers:''' [http://www.math.wisc.edu/~jeanluc/ Jean-Luc Thiffeault], [http://pages.cs.wisc.edu/~swright/ Steve Wright]  
 +
*'''To join the SIAM Chapter mailing list:''' email [join-siam-chapter@lists.wisc.edu].
  
 
<br>
 
<br>
  
 
+
== Fall 2019 ==
== Fall 2018 ==
 
  
 
{| cellpadding="8"
 
{| cellpadding="8"
Line 18: Line 16:
 
!align="left" | title
 
!align="left" | title
 
|-
 
|-
| Sept. 12
+
|Sept. 27, Oct. 4
|[http://www.math.wisc.edu/~ke/ Ke Chen] (Math)
+
|[http://www.math.wisc.edu/~xshen/ Xiao Shen] (Math)
|''[[#Sep 12: Ke Chen (Math)|Inverse Problem in Optical Tomography]]''
+
|''[[#Sep 27, Oct 4: Xiao Shen (Math)|The corner growth model]]''
 +
|-
 +
|-
 +
|Oct. 18
 +
|[https://scholar.google.com/citations?user=7cVl9IkAAAAJ&hl=en Bhumesh Kumar] (EE)
 +
|''[[#Oct 18: Bhumesh Kumar (EE)|Non-stationary Stochastic Approximation]]''
 +
|
 +
|-
 
|-
 
|-
| Spet. 26 
+
|Oct. 25
|[http://www.math.wisc.edu/~kehlert/ Kurt Ehlert] (Math)
+
|Max (Math)
|''[[#Sept 26: Kurt Ehlert (Math)| How to bet when gambling]]''
+
|''[[#Oct 25: Max (Math)|Coalescent with Recombination]]''
 +
|
 
|-
 
|-
| Oct. 10 
 
|[http://TBD Zachary Hansen] (Atmospheric and Oceanic Sciences)
 
|''[[#Oct 10: Zachary Hansen (Atmospheric and Oceanic Sciences)|  Land-Ocean contrast in lightning  ]]''
 
 
|-
 
|-
| Oct. 24 
+
|Nov. 8
|[http://TBD Xuezhou Zhang] (Computer Science)
+
|Hongfei Chen (Math)
|''[[#Oct 24: Xuezhou Zhang (Computer Science)| An Optimal Control Approach to Sequential Machine Teaching  ]]''
+
|''[[#Nov 15: Hongfei Chen (Math)| Brownian swimmers in a channel]]''
 +
|
 
|-
 
|-
| Nov. 7
 
|[http://TBD Cancelled]
 
|''[[#Nov 7: Cancelled|  ]]''
 
 
|-
 
|-
| Nov. 21
+
|Dec. 10
|[http://TBD Cancelled due to Thanksgiving]  
+
|[http://www.maths.manchester.ac.uk/~higham/ Nicholas J. Higham] (University of Manchester)
|''[[#Nov 21: Cancelled| ]]''
+
|''[[#Dec 10: Nicholas J. Higham  (University of Manchester)|Scientific Writing]]''
 
|-
 
|-
| Nov. 28
 
|[http://TBD Xiaowu Dai] (Statistics)
 
|''[[#Nov 28: Xiaowu Dai (Statistics)| TBD  ]]''
 
 
|-
 
|-
 
|
 
|
 
|}
 
|}
  
 +
== Abstracts ==
 +
 +
=== Sep 27, Oct 4: Xiao Shen (Math) ===
 +
'''The corner growth model'''
  
== Abstract ==
+
Imagine there is an arbitrary amount of donuts attached to the integer points of Z^2. The goal is to pick an optimal up-right path which allows you to eat as much donuts as possible along the way. We will look at some basic combinatorial observations, and how specific probability distribution would help us to study this model.
  
=== Sep 12: Ke Chen (Math) ===
+
=== Oct 18: Bhumesh Kumar (EE) ===
Inverse Problem in Optical Tomography
+
'''Non-stationary Stochastic Approximation'''
  
I will briefly talk about my researches on the inverse problems of radiative transfer equations, which is usually used as a model to describe the transport of neutrons or other particles in a certain media. Such inverse problems considers the following question: given the knowledge of multiple data collected at the boundary of the domain of interest, is it possible to reconstruct the optical property of the interior of media? In this talk, I will show you that stability of this problem is deteriorating as the Knudsen number is getter smaller. The talk will be introductory and anyone graduate is welcome to join us.
+
Abstract: Robbins–Monro pioneered a general framework for stochastic approximation to find roots of a function with just noisy evaluations.With applications in optimization, signal processing and control theory there is resurged interest in time-varying aka non-stationary functions. This works addresses that premise by providing explicit, all time, non-asymptotic tracking error bounds via Alekseev's nonlinear variations of constant formula.  
  
=== Sept 26: Kurt Ehlert (Math) ===
+
Reference: https://arxiv.org/abs/1802.07759 (To appear in Mathematics of Control, Signals and Systems)
How to bet when gambling
 
  
When gambling, typically casinos have an edge. But sometimes we can gain an edge by counting cards or other means. And sometimes we have an edge in the biggest casino of all: the financial markets. When we do have an advantage, then we still need to decide how much to bet. Bet too little, and we leave money on the table. Bet too much, and we risk financial ruin. We will discuss the "Kelly criterion", which is a betting strategy that is optimal in many senses.
+
=== Oct 25: Max (Math) ===
 +
'''Coalescent with Recombination'''
  
=== Oct 10: Zachary Hansen (Atmospheric and Oceanic Sciences) ===
+
I will talk about the continuous time coalescent with mutation and recombination, with a focus on introducing key concepts related to genetic distance and evolutionary relatedness. The talk will be informal and accessible.
Land-Ocean contrast in lightning
 
  
Land surfaces have orders of magnitude more lightning flashes than ocean surfaces. One explanation for this difference is that land surfaces may generate greater convective available potential energy (CAPE), which fuels stronger thunderstorms. Using a high resolution cloud-resolving atmospheric model, we test whether an island can produce stronger thunderstorms just by having a land-like surface. We find that the island alters the distribution of rainfall but does not produce stronger storms. An equilibrium state known as boundary layer quasi-equilibrium follows, and is explored in more detail.
+
=== Nov 15: Hongfei Chen (Math) ===
 +
'''Brownian swimmers in a channel'''
  
=== Oct 24: Xuezhou Zhang (Computer Science) ===
+
Abstract: Shape matters! I will talk about how their shapes affect their mean reversal time.
An Optimal Control Approach to Sequential Machine Teaching
 
  
Given a sequential learning algorithm and a target model, sequential machine teaching aims to find the shortest training sequence to drive the learning algorithm to the target model. We present the first principled way to find such shortest training sequences. Our key insight is to formulate sequential machine teaching as a time-optimal control problem. This allows us to solve sequential teaching by leveraging key theoretical and computational tools developed over the past 60 years in the optimal control community. Specifically, we study the Pontryagin Maximum Principle, which yields a necessary condition for opti- mality of a training sequence. We present analytic, structural, and numerical implica- tions of this approach on a case study with a least-squares loss function and gradient de- scent learner. We compute optimal train- ing sequences for this problem, and although the sequences seem circuitous, we find that they can vastly outperform the best available heuristics for generating training sequences.
+
=== Dec 10: Nicholas J. Higham (University of Manchester) ===
 +
'''Scientific Writing'''
  
=== Nov 7: Cancelled ===
+
I will discuss various aspects of scientific writing, including
  
=== Nov 21: Cancelled ===
+
• the craft of writing in general,
  
=== Nov 28: Xiaowu Dai (Statistics) ===
+
• aspects specific to mathematical writing,
TBD
 
  
TBD
+
• English Usage,
 +
 
 +
• workflow, and
 +
 
 +
• revising drafts and proofreading.
 +
 
 +
Plenty of examples and links to further information will be given. I will also discuss
 +
my experiences in preparing ''Handbook of Writing for the Mathematical Sciences'' (third
 +
edition, SIAM, 2020).
  
  
 
<br>
 
<br>
 +
 +
== Past Semesters ==
 +
*[[SIAM_Student_Chapter_Seminar/Fall2018|Fall 2018]]
 +
*[[SIAM_Student_Chapter_Seminar/Spring2017|Spring 2017]]
 +
*[[SIAM_Student_Chapter_Seminar/Fall2019|Fall 2019]]

Revision as of 14:17, 21 January 2020


  • When: Most Friday at 11:30am
  • Where: 901 Van Vleck Hall
  • Organizers: Xiao Shen
  • Faculty advisers: Jean-Luc Thiffeault, Steve Wright
  • To join the SIAM Chapter mailing list: email [join-siam-chapter@lists.wisc.edu].


Fall 2019

date speaker title
Sept. 27, Oct. 4 Xiao Shen (Math) The corner growth model
Oct. 18 Bhumesh Kumar (EE) Non-stationary Stochastic Approximation
Oct. 25 Max (Math) Coalescent with Recombination
Nov. 8 Hongfei Chen (Math) Brownian swimmers in a channel
Dec. 10 Nicholas J. Higham (University of Manchester) Scientific Writing

Abstracts

Sep 27, Oct 4: Xiao Shen (Math)

The corner growth model

Imagine there is an arbitrary amount of donuts attached to the integer points of Z^2. The goal is to pick an optimal up-right path which allows you to eat as much donuts as possible along the way. We will look at some basic combinatorial observations, and how specific probability distribution would help us to study this model.

Oct 18: Bhumesh Kumar (EE)

Non-stationary Stochastic Approximation

Abstract: Robbins–Monro pioneered a general framework for stochastic approximation to find roots of a function with just noisy evaluations.With applications in optimization, signal processing and control theory there is resurged interest in time-varying aka non-stationary functions. This works addresses that premise by providing explicit, all time, non-asymptotic tracking error bounds via Alekseev's nonlinear variations of constant formula.

Reference: https://arxiv.org/abs/1802.07759 (To appear in Mathematics of Control, Signals and Systems)

Oct 25: Max (Math)

Coalescent with Recombination

I will talk about the continuous time coalescent with mutation and recombination, with a focus on introducing key concepts related to genetic distance and evolutionary relatedness. The talk will be informal and accessible.

Nov 15: Hongfei Chen (Math)

Brownian swimmers in a channel

Abstract: Shape matters! I will talk about how their shapes affect their mean reversal time.

Dec 10: Nicholas J. Higham (University of Manchester)

Scientific Writing

I will discuss various aspects of scientific writing, including

• the craft of writing in general,

• aspects specific to mathematical writing,

• English Usage,

• workflow, and

• revising drafts and proofreading.

Plenty of examples and links to further information will be given. I will also discuss my experiences in preparing Handbook of Writing for the Mathematical Sciences (third edition, SIAM, 2020).



Past Semesters