(2 p.m. - 3 p.m.)

**Nozer D. Singpurwalla**

**City University of Hong Kong**

**Subjective Probability: Its Content, Axioms, and Acrobatics**

What sense can one make of the claim that “the probability of a nuclear accident is .003?” Surprisingly, the answer is difficult because there are many interpretations of quantified uncertainty, each burdened by its own baggage. This expository talk is a historical journey, which traces development of the topic from Cardano (1501 -1575) to Kolmogorov (1956), with stops at Bayes, La Place, Ramsey, Keynes, Venn, Borel, de Finetti and Popper.

An interpretation that is immune to logical attack is that of Subjective (or Personal) Probability – to Richard Jeffrey “The Real Thing!” It is a corporate state of mind rather than an innate verifiable property of the real world. This viewpoint, now at the very doorstep of *Quantum Physics*, is defended by notions of coherence and rationality, which is an elaborate system of axioms about preferences, consequences and acts, which lead to the claim that pure probability cannot be isolated from preference. Hidden therein is the axiom of acrobatics (my term) which operationalizes subjective probability and levels the playing field.

This talk is expository, open to engineers, scientists, mathematicians, and social biological scientists, and does not call for any background in the technical aspects of probability.

Biography:

Nozer D. Singpurwalla is currently a Chair Professor at The City University of Hong Kong with appointments in the Engineering and the Business Schools. He is a Fellow of the ASA, the IMS, the AAAS, and an elected member of the ISI. His current interests are in probability modeling, filtering, the foundational aspects of Bayesian inference, and the probabilistic aspects of quantum theory.

Sponsored by the Department of Mathematical Sciences at The University of Texas at Dallas and joint with Southern Methodist University

]]>(3 p.m. - 4 p.m.)

**Eric Rawdon**

**Department of Mathematics**

**University of St. Thomas**

**Knotting in open chains, closed chains, and proteins**

Some proteins (in their folded functional form) are classified as being knotted. The function of protein knotting is mysterious since knotting seemingly would make the folding process unnecessarily complicated. To function, proteins need to fold quickly and reproducibly, and misfolding can have catastrophic results. For example, mad cow disease and the human equivalent, Creutzfeldt-Jakob disease, come from misfolded proteins. We hope to understand knotting in proteins to make the world a better place.

Proteins have two free ends, as do most of the objects humans consider as being knotted (like shoelaces and garden hoses). However, mathematically, knotting is only defined for closed curves. Defining knotting in open curves, like proteins, is tricky and ambiguous, but we will give it a try. In particular, in this seminar we will talk about mathematical knots, knots in nature, knots in open curves, and knots in proteins.

Link to Eric’s Research Gate page: https://www.researchgate.net/profile/Eric_Rawdon

Sponsored by the Department of Mathematical Sciences

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