Madison Chaos and Complex Systems Seminar

Fall 2013 Seminars

All seminars are Tuesday at 12:05 pm in 4274 Chamberlin Hall except as noted. Refreshments will be served.

Short List


September 3, 2013

The taxonomy of fuels

Jim Blair, Milton and Edgewood College
Jim Blair image

September 10, 2013

Multistability and hidden attractors

Clint Sprott, UW Department of Physics

One characteristic of nonlinear dynamical systems is that they can have more than one stable equilibrium. Perturbations of the variables or changes in the parameters can cause the system to abruptly switch from one equilibrium to the other from which it is hard to recover (what Al Gore calls a "tipping point"). Furthermore, equilibria can become unstable and give birth to periodic oscillations and even chaos. Hence, in addition to static attractors, there can be limit cycles and strange attractors, and several such attractors can coexist in even simple systems. Sometimes these attractors are "hidden" in the sense that they cannot be found by starting from the vicinity of an unstable equilibrium. Such hidden attractors can be catastrophic if the system is a building, a bridge, or an airplane wing. Examples of such behavior will be illustrated in very simple systems of differential equations and with simple demonstrations.

This talk is available as a PowerPoint presentation.

September 17, 2013

Scaling wireless network capacity with node density

Xinyu Zhang, UW Department of Electrical and Computer Engineering

Wireless spectrum is limited, so packing more devices into limited spectrum is the key to improving network capacity. Yet the current infrastructure wireless networks are interference-limited. Their capacity does not scale with the density of infrastructure nodes (i.e., the access points, or APs). This lack of scalability clearly mismatches the wireless traffic demand that is growing with user density. In this talk, I will introduce a novel network architecture, NEMOx, that can scale wireless network capacity with AP density. NEMOx organizes a network into practical-size clusters, each containing multiple distributed APs (dAPs) that opportunistically synchronize and cooperate with each other. Inter-cluster interference is managed with a decentralized channel-access algorithm, which is designed to balance between the dAPs' cooperation gain and spatial reuse. Within each cluster, NEMOx optimizes the power budgeting among dAPs and the set of users to serve, ensuring fairness and effective cancellation of cross-talk interference. We have implemented and evaluated a prototype of NEMOx in a software radio testbed, demonstrating its throughput scalability and multiple folds of performance gain over current wireless LAN architecture.

September 24, 2013

Hydrogen energy levels in n dimensions via group theory

Adam Bincer, UW Department of Physics

My talk is a generalization to n dimensions of a brilliant group-theoretical treatment of the hydrogen energy levels by Pauli in 1926. To start I define the concept of a group and discuss cyclic groups as a simple example. Then the rotation group in two dimensions is introduced to get us started on Lie groups. From there it is just a short hop to rotations in n dimensions. Along the way I introduce the idea of matrices - hopefully all this mathematics will be introduced gently enough so as not to turn the non mathematicians in the audience completely off. I then turn to the non-relativistic hydrogen atom in n dimensions and show how it is governed by the rotation group in (n+1) dimensions. I conclude with some anecdotes about Pauli.

October 1, 2013

Aging and delayed aging by caloric restriction

Rozalyn Anderson, UW School of Medicine and Public Health

Biology of aging research provides insights into the molecular and cellular aspects of the aging process and the factors contributing to the increase in disease vulnerability observed with advancing age. Caloric restriction (CR) without malnutrition delays aging and extends lifespan in diverse species. In exploring CR’s mechanisms we stand to gain a unique perspective on the biology of aging, including the complex nature of its underlying regulatory processes.

October 8, 2013

A convenient consistency -A short summary of the large history of infinitesimals

Terry Millar, UW Department of Mathematics

This talk will be a quick look at the birth (Democritus 450 B.C.E.), use (Archimedes, Leibniz, Newton, physicists, engineers....), persecution (Eudoxus, Berkeley, Russell,...), death (Bolzano, Cauchy,... Weirstrauss 19th Century), and resurrection (Robinson 1960) of infinitesimals as a mathematical construct.

October 15, 2013

From here to there:  From neuroscience of the human  brain to complex system realities in  every day human life

Bernard Z. Friedlander, Department of Psychology, Emeritus, University of Hartford, West Hartford, CT

Can we adapt burgeoning progress in neurocellular electrochemistry to human behavior in the disorderly theaters of real life in which our individual and social narratives unfold?  Can we identify critical conceptual and practical issues that must be recognized and solved if we are to reconcile the divergent criteria of explanatory natural sciences and the interpretive sciences of human behavior?

This talk is available as a PowerPoint presentation along with a PowerPoint addendum.

October 22, 2013

A physics approach to understanding complex networks

Michelle Girvan, University of Maryland (Clay Memorial Lecture)

Many natural, technological, and social systems take the form of networks. Examples include metabolic networks, the Internet, and friendship networks.  In the last decade or so, the new field of “network science” has emerged, with physicists playing a key role applying methods from statistical mechanics and nonlinear dynamics to understand the behavior of these complex networks.  In this talk, I will discuss how a physics approach to such problems can give us new insights into social, biological, and technological systems, and I’ll give several examples from my own research.

This talk was made possible by a generous donation from Jane Clay in memory of her late husband Clarence Clay (1923-2011) who was an active participant in the seminars and who was a student of physics and professor in the Department of Geoscience specializing in oceanography at the University of Wisconsin.

Slides from this talk are available in PDF format.

October 29, 2013

DNA databasing for forensic use
Rohaizah James, Promega Corp

Genetic markers called Short Tandem Repeats (STR) is now routinely used in forensic DNA testing to identify the source of crime scene evidence. A DNA profile containing multiple STR's provides an extremely high probability of identity, leaving little doubt that a match between crime scene evidence and a suspect is not random. Because a large fraction of crimes are committed by repeat offenders, an offender database aids in generating leads and solving crimes. The national DNA database, established in 1998 after Congress passed the DNA Identification Act, now contains over 10 million offender DNA profiles. The ability to search this database has aided over 200,000 investigations. This database also includes over 1.5 million arrestee profiles. Arrestee DNA testing, currently allowed in 29 states, has been controversial. Does the potential benefit of improving public safety outweigh an arrestee's privacy interests? What about familial searching, where a database is searched to identify not the criminal but his/her biological relative? This search method was used successfully in solving the California Grim Sleeper case, where the presence of the criminal’s son in the DNA database led investigators to the father. This presentation will include a discussion on the science behind STR analysis and the practical questions it brings in forensic use.

November 5, 2013

Optimizing the design of air pollution control measures to improve human health

Jamie Schauer, UW Department of Civil and Environmental Engineering

Hundreds of studies have clearly demonstrated that higher levels of air pollution are associated with increases in adverse health effects in human populations.  The adverse health effects associated with air pollution exposure include mortality and morbidity that are linked to respiratory disease, cardiovascular disease, and reproductive complications.  As one of the largest environmental risk factors, the economic costs or air pollution have been estimated to be over one trillion dollars per year in the USA alone.  However, the costs associated with mitigation of air pollution are not trivial and policies for air pollution mitigation often face political and social barriers.  As more effective and efficient control strategies are sought to reduce the impacts of air pollution, a robust understanding of how reduction in the emissions from specific sources will change the composition of air pollution and reduce the adverse impacts of air pollution.  Given the complexity of air pollution sources, air pollution transport and transformations, and the biological pathways of disease associated with air pollution exposure; quantifying these relationships require an understanding of a number of very complex and integrated systems.   These systems include: 1) the design and operations of mobile sources of air pollution, stationary power generation, residential air pollution sources, and industrial emissions of air pollution; 2) the physical and chemical processes of impacting the transport and transformations of pollutants in the atmosphere; 3) the behavioral activities of people that lead to exposures of air pollution, 4) the biological susceptibility of the exposure populations, and 5) the pathways of disease associated with exposure to air pollution.  This seminar will provide background about these systems important to understand the health effects of air pollution, as well as research methods that are being used to bridge across the highly diverse domains.

Slides from this talk are available in PDF format.

November 12, 2013

Tutankhamun's Chariots, Stunt-Kite Ballet, and the Exodus
(Chaos Choreography and Modeling)

Bela Sandor, UW Department of Engineering Physics

What might have happened at the Red Sea between Moses and Pharaoh, if the Exodus story is at least partially true?

Who was Pharaoh? What did he drive, and how, befitting a super-athletic warrior king?

My discovery process combines diverse methods and tools, and gives ideas for future work:

  Analysis of ancient hardware and art; chariot replication and field testing for the NOVA documentary “Building Pharaoh’s Chariot” (original airing Feb. 6, 2013).

 •  Statics and dynamics (including an important abstract concept that Newton missed, though the ancients understood it). Modeling structural dynamics and integrity; time-dependent material behaviors; sophisticated wheels, suspensions, joints, and a dual-function anti-roll mechanism.

 •  Chaos choreography in Bethell’s system of controlling multiple stunt kites, which are sensitive to small changes in stimulation; the method would allow measurements of force vectors at handles and the resulting agent dynamics.

 •  Chaos choreography in high-speed pharaonic war games, with one person handling two horses and two different weapons in a burst event; did Pharaoh use this technique in the Exodus scene? Consider a clear view of all handles and corresponding agents.

  Human factors: Was Pharaoh playing a chaos experiment?

November 19, 2013

A historical introduction to quantum computing

Marty Lichtman, UW Department of Physics

The quantum computer is on the horizon.  If a system is small enough and isolated enough, it behaves according to the weird laws of quantum mechanics.  One of the beautiful behaviors of a quantum system is that it can exist in a "superposition" of multiple states, at the same time.  In the last two decades, physicists, including the 2012 Nobel laureates, have learned to control these systems.  If we think of the state of these systems as a piece of information, we can store a superposition of data.  Then by manipulating the system, a calculation is performed.

The power of this quantum computation is that many calculations may effectively be performed at the same time.  The potential speedup is immense.  A functional quantum computer will certainly bring advances in cryptography, search, and physical simulation, and likely in all areas of science that have hard computational problems.

This talk will present the development of the quantum computer in the historical context of classical computing.  We will discuss the basics of how a quantum computer can speed up certain calculations, and also look at one experimental attempt to build a quantum computer using trapped neutral atoms here at UW-Madison.

November 26, 2013

What is art? Arts Immersion five-year report

Russell Gardner, Jr.
, Medical College of Wisconsin

For five years, a group called Arts Immersion (AIm) met monthly in a variety of venues to discuss questions involving art: What is art broadly speaking, in all its form? How does it relate to other forms of creative activity? How do various forms interact, intertwine, transmute? Why do people do art?  Who are participants under what personal and social circumstances? What about art careers? How do people begin and continue? What is good art? How does audience come into play? What are non-art works and non-artists? How does art relate to spirituality and religion?

The coordinator had a career involving facets of academia, psychiatry and think tank problem exploration, and left a salaried position to move to Madison and do art full-time, at first mostly visual art and now mostly writing. Along the way he also found himself pondering the issues raised by this prevalent human activity, issues not addressed in other available forums in an exploratory open-minded fashion. Eventually spin-off smaller groups selectively explore more focused areas, such as religion, spirituality and art by concentratedly reviewing relevant books, or a writing support group.

The following represent his conclusions that were not arrived at via group problem solving, but rather represent my individual thinking and conclusions.

1.     Art stems from a person’s creativity that may take a myriad of forms from cooking to crafts to high end visual art featured in museums to music to architecture, landscape design to evanescent re-arrangement of natural settings and going to extremes of composing by oneself, participating in jam sessions, performing, listening. Calling it art versus creative expression depends on cultural endorsement and group definition.

2.     Audience-involvement counts as even listening, watching, reading, or hearing fragments of productions on the radio or television.

3.     “Significance experiences” that characterize the lives of saints or religious figures also pervade the histories of artists and creative scientists. Knowing about the behavior of patients or historical figures with temporal lobe seizures informs this discussion. This also relates to the “pleasure” of doing art, and other reinforcing featues.

4.     Ancillary features of art also shape, guide and motivate the artist(s) such as scholarly explorations, personal therapy,  spiritual realizations, and missions such as amplifying nationalism in war-fever, religious fervor, quests for peace.

December 3, 2013

What happens when policy comes before science?

Sherry Tanumihardjo, UW Department of Nutritional Sciences

Vitamin A is essential for multiple functions in mammals. Without vitamin A, mammals cannot grow, reproduce, or fight off disease. Because of its numerous functions in humans, biomarkers of vitamin A status are quite diverse. Assessment of liver reserves of vitamin A is considered the gold standard because the liver is the major storage organ. However, this measure is not feasible in human studies. Alternative biomarkers of status can be classified as biological, functional, histologic, and biochemical. Before overt clinical damage to the eye, individuals who suffer from vitamin A deficiency are plagued by night blindness and longer vision-restoration times. These types of assessments require large population-based evaluations. Therefore, surrogate biochemical measures of vitamin A status, as defined by liver reserves, have been developed. Serum retinol concentrations are a common method used to evaluate vitamin A deficiency. Often policy is set based on serum retinol concentrations. However, they often do not respond to interventions and do not decline until liver reserves are severely depleted. Therefore, surrogate measures of liver reserves were developed, which include stable isotope and relative dose response tests.

December 10, 2013

Responding to climate change: poetry and local action

Robin Chapman, UW Department of Communicative Disorders, and Jean Bahr, UW Department of Geoscience

What can individuals do? Robin Chapman reads from her new book of poems, One Hundred White Pelicans, work that arose from the Chaos and Complex Systems Seminars on climate change; and Jean Bahr talks about local action, including reroofing her house with solar shingles: they engage the questions of causal contributions to change, now and in the past; why it should matter to us now; and what we can do about it. Students and investigators in the field are especially welcome to contribute to discussion.