I begin by fitting traditional gravity equations to document that regional flows in the Brazilian cement industry exhibit gravity-like structure, with cement trade decaying sharply in distance traveled. I then show that this large distance effect owes to firms' strategic behavior over and above trade costs, with firm-level spatial supply decisions being characterized by the tacitly-collusive di...

This paper introduces ART-EMAP, a neural architecture that uses spatial and temporal evidence accumulation to extend the capabilities of fuzzy ARTMAP. ARTEMAP combines supervised and unsupervised learning and a medium-term memory process to accomplish stable pattern category recognition in a noisy input environment. The ART-EMAP system features (i) distributed pattern registration at a view cat...

A physically based duality theory for first order elliptic systems is shorn to be of central importance in connection with the Galerkin finite element solution of these systems. Using this theory in conjunction with a certain hypothesis concerning approximation spaces, optimal error estimates for Galerkin type approximations are demonstrated. An example of a grid which satisfies the hypothesis ...

We consider an adaptive i~nite state controlled Maxkov chain with partial state information, motivated by a class of replacement problems. We present parameter estimation techniques based on the information ava~lable after actions that reset the state to a known v~ue are taken. We prove that the parameter estimates converge w.p.1 to the true (unknown) parameter, under the feedback structure ind...

We show that symmetric Venn diagrams for n sets exist for every prime n, settling an open question. Until this time, n = 11 was the largest prime for which the existence of such diagrams had been proven, a result of Peter Hamburger. We show that the problem can be reduced to finding a symmetric chain decomposition, satisfying a certain cover property, in a subposet of the Boolean lattice Bn, an...

In this correspondence, we estimate the Hurst parameter H of fractional Brownian motion (or, by extension, the fractal exponent 9 of stochastic processes having 1/ f +‘-like spectra) by applying a recently introduced multiresolution framework. This framework admits an efficient likelihood function evaluation, allowing us to compute the maximum likelihood estimate of this fractal parameter with ...

Because different psychopathologic components of depressive symptoms may have distinct etiologies, examining their differential effects on smoking cessation may elucidate mechanisms underlying the smoking-depression relationship. Negative affect (NA), somatic features (SF), low positive affect/anhedonia (PA), and interpersonal disturbance (IP) have been identified as unique dimensions of depres...

Start by randomly populating each site of the two-dimensional integer lattice with any one of N types, labeled 0,1, , 1 The type at site can the type at neighboring site ( . y y eat x x (i.e., replace the type at with ) that mod We describe the dynamics x y provided y x 1 N. of , discrete-time deterministic systems which follow the rule: cyclic cellular automata (c.c.a. t (•) At any time , each...