8,203 research outputs found
The Dynamics of Metropolitan Housing Prices
This article is the winner of the Innovative Thinking ‘‘Thinking Out of the Box’’ manuscript prize (sponsored by the Homer Hoyt Advanced Studies Institute) presented at the 2001 American Real Estate Society Annual Meeting. This study examines the dynamics of real housing price appreciation in 130 metropolitan areas across the United States. The study finds that real housing price appreciation is strongly influenced by the growth of population and real changes in income, construction costs and interest rates. The study also finds that stock market appreciation imparts a strong current and lagged wealth effect on housing prices. Housing appreciation rates also are found to vary across areas because of location-specific fixed-effects; these fixed effects represent the residuals of housing price appreciation attributable to location. The magnitudes of the fixed-effects in particular cities are positively correlated with restrictive growth management policies and limitations on land availability.
Characterizing partition functions of the edge-coloring model by rank growth
We characterize which graph invariants are partition functions of an
edge-coloring model over the complex numbers, in terms of the rank growth of
associated `connection matrices'
Finding k partially disjoint paths in a directed planar graph
The {\it partially disjoint paths problem} is: {\it given:} a directed graph,
vertices , and a set of pairs from
, {\it find:} for each a directed path
such that if then and are disjoint.
We show that for fixed , this problem is solvable in polynomial time if
the directed graph is planar. More generally, the problem is solvable in
polynomial time for directed graphs embedded on a fixed compact surface.
Moreover, one may specify for each edge a subset of
prescribing which of the paths are allowed to traverse this edge
On traces of tensor representations of diagrams
Let be a set, of {\em types}, and let \iota,o:T\to\oZ_+. A {\em
-diagram} is a locally ordered directed graph equipped with a function
such that each vertex of has indegree
and outdegree . (A directed graph is {\em locally ordered} if at
each vertex , linear orders of the edges entering and of the edges
leaving are specified.)
Let be a finite-dimensional \oF-linear space, where \oF is an
algebraically closed field of characteristic 0. A function on assigning
to each a tensor is called a {\em tensor representation} of . The {\em trace} (or {\em
partition function}) of is the \oF-valued function on the
collection of -diagrams obtained by `decorating' each vertex of a
-diagram with the tensor , and contracting tensors along
each edge of , while respecting the order of the edges entering and
leaving . In this way we obtain a {\em tensor network}.
We characterize which functions on -diagrams are traces, and show that
each trace comes from a unique `strongly nondegenerate' tensor representation.
The theorem applies to virtual knot diagrams, chord diagrams, and group
representations
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