George Ehrhardt

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We study the Potts model on locally tree-like random graphs of arbitrary degree distribution. Using a population dynamics algorithm we numerically solve the problem exactly. We confirm our results with simulations. Comparisons with a previous approach are made, showing where its assumption of uniform local fields breaks down for networks with nodes of low(More)
We study a general set of models of social network evolution and dynamics. The models consist of both a dynamics on the network and evolution of the network. Links are formed preferentially between "similar" nodes, where the similarity is defined by the particular process taking place on the network. The interplay between the two processes produces phase(More)
We study a simple model of a population of agents whose interaction network co-evolves with knowledge diffusion and accumulation. Diffusion takes place along the current network and, reciprocally, network formation depends on the knowledge profile. Diffusion makes neighboring agents tend to display similar knowledge levels. On the other hand, similarity in(More)
In this study, an attempt was made to modify hearing preschoolers' frequent and persistent refusal to interact with profoundly deaf peers. Half of the hearing children involved in a low-key mainstreaming program participated in a special 3-week training program that included discussions about the meaning of deafness, an opportunity to practice communication(More)
We consider the persistence probability, the occupation-time distribution, and the distribution of the number of zero crossings for discrete or (equivalently) discretely sampled Gaussian stationary processes (GSPs) of zero mean. We first consider the Ornstein-Uhlenbeck process, finding expressions for the mean and variance of the number of crossings and the(More)
A report is given in a case of appendicitis after delivery in childbed. This was the third case of appendicitis within 17 657 deliveries in the gestation of the district hospital in Sangerhausen in the period from 1960 to 1975. The chronic relapsed appendicitis produced a paralytic Ileus. By using correspondent measures (infusional therapy, appendectomy,(More)