This paper considers a stylized model of network formation in which relations among agents are subject to frictions, as described in Bala and Goyal [A non cooperative model of network formation, Econometrica 68 (2000) 1181–1231]. We analyze the process of network formation in a dynamic framework where selfinterested individuals can form or delete links and, occasionally, make mistakes. Then, us...

Commonly complex cognitive concepts cannot consistently be connected to simple features of the world. Geometrical shape parameters and (e.g., edge features, compactness, color) may play a role for defining individual objects, but might be too variable to allow for concept formation. Earlier works had suggested that the formation of object concepts is strongly influenced by the division of our w...

We show that the oscillatory driving of crystal surfaces can induce pattern formation or smoothening. Depending on driving conditions, step bunching and meandering, mound formation, or surface smoothening may be seen in the presence of a kinetic asymmetry at the steps or kinks. We employ a step model to calculate the induced mass flux along misoriented surfaces, which accounts for surface dynam...

The unique and little practiced characteristics of mobile as a marketing medium create a need to set up an action and research agenda regularly to foster the development of the mobile marketing value system. Numerous stakeholders take part in the network to deliver the mobile services. Strengthening their inter-organizational relationships is critical for the emerging value system to evolve. Ou...

We argue that the linear static potential is built in into the common procedure of extracting it from lattice Wilson loop measurements. To illustrate the point, we extract the potential by the standard lattice method in a model vacuum made of instantons. A beautiful infinitely rising linear potential is obtained in the case where the true potential is actually flattening. We argue that the flux...

This paper presents a new approach to segmentation using explicit hypotheses about the physics that creates images. We propose an initial segmentation that identifies image regions exhibiting constant color, but possibly varying intensity. For each region, we propose a set of hypotheses, each of which specifically models the illumination, reflectance, and shape of the 3-D patch which caused tha...

Adherence of Candida spp. to buccal epithelial cells in vitro was significantly reduced after both short- and long-term periods of yeast exposure to sub-inhibitory concentrations of octenidine and pirtenidine. In addition, the pretreatment of either Candida or the epithelial cells or both with the drugs reduced adherence, this being greatest when both types of cells were pretreated. No differen...

We model network formation when heterogeneous nodes enter sequentially and form connections through both random meetings and network-based search, but with type-dependent biases. We show that there is “long-run integration,” whereby the composition of types in sufficiently old nodes’ neighborhoods approaches the global type distribution, provided that the network-based search is unbiased. Howev...