MSCS Seminar Calendar
Monday November 23, 2009
Computer Science SeminarA cognitive model of recognition-based moral decision making
Morteza Deghani (Northwestern Univ.)
3:00 PM in SEO 427
The study of decision making has been dominated by economic perspectives,
which model people as rational agents who carefully weigh costs and benefits
and try to maximize the utility of every choice, without consideration of
issues such as cultural norms, religious beliefs and moral rules which exist
outside the market. However, psychological findings indicate that in many
situations people are not optimal nor rational decision makers as defined by
the economic theories. One of the domains in which the rational actor
perspective fails to explain human behavior is that of moral decision
making. A body of research illustrates that in the presence of moral values,
such as those outlined in religious texts or folk stories, people tend to
focus on the obligations and duties outlined in their culture and as a
result are less concerned about the outcome utility of their choice.
In this talk, I present a computational model of recognition-based moral
decision making, MoralDM, which integrates several AI techniques in order to
model recent psychological findings on moral decision making. MoralDM uses a
natural language system to produce formal representations from psychological
stimuli, reducing tailorability. The impacts of secular versus sacred values
are modeled via qualitative reasoning, using an order of magnitude
representation. MoralDM uses a combination of first-principles reasoning and
analogical reasoning to determine consequences and utilities when making
moral judgments. I describe how MoralDM works and show that it can model
psychological results and capture the impact of cultural narratives on
decision making.
Geometry, Topology and Dynamics SeminarLocal entropy averages and projection of fractal measures
Mike Hochman (Princeton)
3:00 PM in SEO 612
If X is a compact set in the plane then, by a classical theorem of Marstrand, almost every projection onto a line maps X to a set of the maximal possible Hausdorff dimension,
i.e. the smaller of dim(X) and 1. While in general the set of exceptional direction can be large, in certain situations arising from dynamical, arithmetic or combinatorial contexts,
it is predicted that there should be either no exceptions, or some small explicit set of exceptions. One example of this is an old conjecture of Furstenberg's, predicting that,
if X=A\times B, and A,B are, respectively, subsets of the unit interval invariant under times-2 mod 1 and times-3 mod 1, then the image of X under projection should behave
in this manner for every (not just almost every) projection, the only exceptions being the coordinate projections.
I will explain the background of this problems and my recent work with Pablo Shmerkin in which we resolve this conjecture positively. If time permits I will describe some other
applications of our methods.
Analysis SeminarBernstein "lethargy" phenomenon revisited.
Timur Oikberg (UC Irvine.)
4:00 PM in SEO 636
A classical theorem of S.Bernstein states that, for any increasing
sequence of finite dimensional subspaces $E_1 \hookrightarrow E_2
\hookrightarrow \ldots \hookrightarrow X$ ($X$ is a Banach space),
and for any sequence $\alpha_i \searrow 0$, there exists $x \in X$
s.t. $dist(x,E_i) = \alpha_i$ for every $i$. In this talk, we
present several related results.
(1) Establishing a non-commutative version of Bernstein's result,
we prove that, for any pair of infinite dimensional Banach spaces
$X$ and $Y$, and for any sequence $\alpha_i \searrow 0$, there
exists $T \in B(X,Y)$ whose sequences of approximation, Gelfand,
and Kolmogorov numbers ``behave like'' $(\alpha_i)$. Other $s$-scales
are also considered.
(2) We show that, for many dictionaries in Banach spaces (including
Markushevich bases, and also certain highly redundant dictionaries),
the error of the best $n$-term approximation may decay arbitrarily
slowly.
Part of this work was carried out in collaboration with J.Almira.
Tuesday December 1, 2009
Logic SeminarGalois Groups in Valued D-Fields.
Meghan Anderson (UCBerkeley)
4:00 PM in SEO 612
The theory of valued D-fields provides an interesting setting for the study of difference and differential Galois groups. The extra structure provided by the valuation can be used to relate groups arising from these two types of equations; however, these groups are not always what one might expect. I will talk about the some of the advantages and limitations of working in this particular theory, and look at a few specific equations.
seminar begins with tea
Wednesday March 3, 2010










