AMORPHOUSFor coherent behavior from vast numbers of unreliable microsensors, actuators, and communication devices interconnected in unknown ways, apply the lessons of cellular cooperation in biological organisms.O ver the next few decades, two emerging technologies-microfabrication and cellular engineering-will make it possible to assemble systems incorporating myriads of informationprocessing units at almost no cost, provided all units need not work correctly and that there is no need to manufacture precise geometrical arrangements among them. The shift to this technology will precipitate fundamental changes in methods for constructing and programming computers, and in our view computation itself Microelectronic mechanical components have become so inexpensive to manufacture we can anticipate integrating logic circuits, microsensors, actuators, and communications devices on the same chip to produce particles that could be mixed with bulk materials, such as paints, gels, and concrete. Imagine coating bridges and buildings with smart paint that senses and reports on traffic and wind loads and monitors structural integrity. A smart-paint coating on a wall could sense vibrations, monitor the premises for intruders, and cancel noise.Even more striking is the amazing progress in understanding the biochemical mechanisms in individual cells, promising that we'll be able to harness these mechanisms to construct digital logic circuits.^

We explore a simplified class of models we call swarms, which are inspired by the collective behavior of social insects. We perform a mean-field stability analysis and perform numerical simulations of the model. Several interesting types of behavior emerge in the vicinity of a second-order phase transition in the model, including the formation of stable lines of traffic flow, and memory reconstitution and bootstrapping. In addition to providing an understanding of certain classes of biological behavior, these models bear a generic resemblance to a number of pattern formation processes in the physical sciences.

We describe a purely confidence-based geographic term disambiguation system that crucially relies on the notion of "positive" and "negative" context and methods for combining confidence-based disambiguation with measures of relevance to a user's query.

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The notion of fitness is central in evolutionary biology. We use a simple spatially extended predator-prey or host-pathogen model to show a generic case where the average number of offspring of an individual as a measure of fitness fails to characterize the evolutionary dynamics. Mutants with high initial reproduction ratios have lineages that eventually go extinct due to local overexploitation. We propose general quantitative measures of fitness that reflect the importance of time scale in evolutionary processes.