We exhibit a quantum circuit that performs the Quantum Fourier Transform on $n$ qubits in $ (n)$ depth. Thus, a parallel quantum computer can carry out the QFT in linear time. We conjecture that this can, in fact, be reduced to $ ({\rm log} n)$ depth, which would place the QFT in the class {\bf...

Success and efficiency of Darwinian evolution is based on the dichotomy of genotype and phenotype: The former is the object under variation whereas the latter constitutes the target of selection. Genotype-phenotype relations are highly complex and hence variation and selection appear...

An agent-based computational model of Long House Valley, in northern Arizona near Monument Valley, is described and demontrated. The model, that runs from about AD 400 to 1400, consists of artificial adaptive agents (households) who inhabit a digitized version of the Long House Valley landscape....

A new mathematical representaion is proposed for the configuration space structure induced by recombination which we called "P-structure." It consists of a mapping of pairs of objects to the power set of all objects in the search space. The mapping assigns to each pair of parental "genotypes"...

Following Pollack, we consider a model of analog computer which can recognize various languages in real time. We encode an input word as a point in R[super d] by composing iterated maps, and then apply inequalities to the resulting point to test for membership in the language. <p> Each class of...</p>

Extinction has been seldom considered as a relevant ingredient of neodarwinian theories. The fact, however, is that the number of species extinctions in the history of life is almost the same as the number of originations. The fossil record indicates that extinction events are patterned in some...

This report is concerned with an implementation of a family of models of complex adaptive systems called Echo models. In what follows, you will find: An Introduction to Echo; Information on how to obtain, install and run the Echo system; A description of Echo's graphical interface and...

A class of minimal models is constructed that can exhibit several salient phenomena associated with T-Cell inoculations that prevent and cure auto-immune disease. The models consist of differential equations for the magnitude of two populations, the effectors {\it E} (which cause the disease),...

The problem of protecting computer systems can be viewed generally as the problem of learning to distinguish {\it self} from {\it other}. We describe a method for change detection which is based on the gereration of T cells in the immune system. Mathematical analysis reveals computational costs...