Madison
Chaos and Complex Systems Seminar
Spring 2020 Seminars
All seminars are Tuesday at 12:05 pm in 4274
Chamberlin
Hall except as noted. Refreshments will be served.
Short List
- Jan 21, 2020 - Pupa Gilbert, Physics
- Jan 28, 2020 - Nan Chen, Mathematics
- Feb 4, 2020 - Mike Ries, Anesthesiology
- Feb 11, 2020 - Kangwook Lee, Electrical and Computer
Engineering
- Feb 18, 2020 - Tom Givnish, Botany
- Feb 25, 2020 - Seth Pollak, Psychology
- Mar 3, 2020 - Derrick Herndon, Space Science and Engineering
Center
- Mar 10, 2020 - Siyao Xu, Astronomy
- Mar 17, 2020 - NO SEMINAR (spring break)
- Mar 24, 2020 - Cancelled due to COVID-19
- Mar 31, 2020 - Cancelled due to COVID-19
- Apr 7, 2020 - Cancelled due to COVID-19
- Apr 14, 2020 - Cancelled due to COVID-19
- Apr 21, 2020 - Cancelled due to COVID-19
- Apr 28, 2020 - Cancelled due to COVID-19
Join us for lunch
during the summer on the Memorial
Union Terrace at noon each Tuesday, starting May 5th!
Abstracts:
January 21, 2020
Color: Physics and perception
Pupa Gilbert, UW Department of Physics
Unless we are colorblind or are in the dark, as soon as we look at
any object, we know what color the object is. Simple, isn’t it? No,
not really. The color we see is rarely just determined by the
physical color, that is, the wavelength of visible light associated
with that color. Other factors, such as the illuminating light, or
the brightness surrounding a certain color, affect our perception of
that color. Most striking, and useful, is understanding how the
retina and the brain work together to interpret the color we see,
and how they can be fooled by additive color mixing, which makes it
possible to have color screens and displays. I will show the
physical origin of all these phenomena and give live demos as I
explain how they work. Bring your own eyes!
For more information: (1) watch TED talk: “Color: Physics
and Perception” and (2) read book: PUPA Gilbert and W Haeberli
“Physics in the Arts”, ISBN 9780123918789.
January 28, 2020
A conditional Gaussian framework for assimilating and predicting
complex nonlinear turbulent dynamical systems
Nan Chen, UW Department of Mathematics
A conditional Gaussian nonlinear and non-Gaussian framework is
developed and is applied to study data assimilation, uncertainty
quantification and prediction of complex nonlinear turbulent
dynamical systems. The talk will contain the following topics:
recovering turbulent ocean flows, predicting non-Gaussian atmosphere
phenomena including extreme events, solving the time evolution of
high-dimensional probability density function, parameter estimation
and recovering the hidden states in complex systems.
February 4, 2020
Anesthesia in the Anthropocene: Environmental and economic
considerations of modern anesthesia and surgery
Mike Ries, UW Department of Anesthesiology
Climate health and population health are undeniably and inextricably
linked. As healthcare institutions maintain a moral obligation to
the healing of all the world's citizens, and healthcare being a
significant, environmentally burdensome business, there exists a
large motive and opportunity for "greening" healthcare. Even
further, the operating room has been singled out as the most
polluting and most energy-intensive part of the modern healthcare
ecosystem. As the perioperative expert, this places a moral and
economic obligation on anesthesiologists to improve environmental
standards in the operating room. During this talk we will discuss
the complex environmental and economic problems facing the
healthcare industry and more specifically how "greening" the OR is
the right choice for checkbooks and our environment alike.
February 11, 2020
Learning with scarce data: The role of side information, simulators,
and GANs
Kangwook Lee, UW Department of Electrical and Computer Engineering
In this talk, I will present the role of side information,
simulators, and GANs for learning with scarce data. In the
first part, I will talk about the role of similarity graphs in
recommendation systems. In the second part, the role of
simulators and GANs will be discussed.
February 18, 2020
Drivers of megadiversity in the orchids, the largest family of
flowering plants
Tom Givnish, UW Department of Botany
Orchids are the most diverse family of angiosperms, with more
species than mammals, birds, and reptiles combined. Many ideas
have been advanced to account for their extraordinary diversity,
but they have – until quite recently – been impossible to test
because we lacked a good phylogeny (family tree) for the orchids.
My colleagues and I have now developed a well-resolved phylogeny
for the orchids, based on large numbers of chloroplast genes, and
I will show how we can use this phylogeny to identify the age and
place of origin of the orchids, assess the role of different
orchid traits in driving high rates of speciation, and reconstruct
the geographic spread of orchids across the planet. I will also
describe some of the remarkable aspects of the ecology of this
endlessly fascinating group that have recently come to light,
mention some of the notable aspects of orchid diversity in
Wisconsin, and sketch some interesting scientific and conservation
issues that should be explored in the future.
February 25, 2020
The emergence of human emotions: Learning, development and biology
Seth Pollak, UW Department of Psychology
Theories about the emergence of human emotion have traditionally
emphasized evolutionarily preserved, universal aspects of emotion
or the functional and cultural adaptations of emotions. While
these opposing views make different assumptions about the initial
state of emotion in the brain, both theories devote little
attention to or specification about potential processes for
learning and developmental change. This colloquium will focus on
the question of how brain and behavior are shaped and refined by
children's early social and emotional experiences. To do so, I
will describe recent research involving children who have
experienced aberrant early life experiences. These include child
abuse and neglect, children raised in extreme poverty, children
raised in institutional settings, and children who have endured
traumatic life experiences. Studies of these children provide new
insights about the developmental processes underlying
socio-emotional learning as well as shed light on the mechanisms
through which children acquire emotions. In addition to these
basic science questions, children raised in adverse environments
are at increased risk for a variety of health, academic, and
social problems. I will highlight ways in which research in this
area can both address central issues in human development as well
as hold tremendous promise for improving the health and well-being
of children.
March 3, 2020
The complexities of conveying hurricane forecast uncertainty to
the public
Derrick Herndon, Space Science and Engineering Center
Tropical Cyclones (Hurricanes) are one of the most violent and
dynamic storms on our planet. Each year an average of 80
tropical cyclones develop over the warm tropical oceans.
Most of these storms spin harmlessly at sea. Others
bring extreme winds, torrential rainfall and surges from the ocean
ashore to devastating effect. Significant progress has been
made in our ability to forecast the development and track of these
storms over the last few decades. However, substantial
challenges remain. Our ability to forecast the internal
dynamics that drive the changes in storm intensity have not quite
kept pace with other aspects of the forecast problem.
Providing accurate and meaningful forecast information for an
inherently chaotic system to the public is also a continuing
challenge. This talk will explore recent advances in our
understanding of these storms along with some remaining challenges
related to the complex interactions between people and hurricanes.
March 10, 2020
The role of turbulence in the universe
Siyao Xu, UW Department of Astronomy
Turbulence is everywhere in our daily life. The same turbulence in
our blood vessels, coffee, rivers, etc. also exists in
the universe over a vast range of length scales from planets to
the large scale structure of the universe. The same physics of
turbulence, including mixing, diffusion, dynamo amplification,
applies to diverse astrophysical environments. This talk will
introduce astrophysical turbulence and its power in connecting
different astrophysical phenomena, from the most energetic
explosions in the universe to our Sun.