3,744 research outputs found
Abstract State Machines 1988-1998: Commented ASM Bibliography
An annotated bibliography of papers which deal with or use Abstract State
Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm
Bindweeds or random walks in random environments on multiplexed trees and their asympotics
We report on the asymptotic behaviour of a new model of random walk, we term
the bindweed model, evolving in a random environment on an infinite multiplexed
tree. The term \textit{multiplexed} means that the model can be viewed as a
nearest neighbours random walk on a tree whose vertices carry an internal
degree of freedom from the finite set , for some integer . The
consequence of the internal degree of freedom is an enhancement of the tree
graph structure induced by the replacement of ordinary edges by multi-edges,
indexed by the set . This indexing conveys the
information on the internal degree of freedom of the vertices contiguous to
each edge. The term \textit{random environment} means that the jumping rates
for the random walk are a family of edge-indexed random variables, independent
of the natural filtration generated by the random variables entering in the
definition of the random walk; their joint distribution depends on the index of
each component of the multi-edges. We study the large time asymptotic behaviour
of this random walk and classify it with respect to positive recurrence or
transience in terms of a specific parameter of the probability distribution of
the jump rates. This classifying parameter is shown to coincide with the
critical value of a matrix-valued multiplicative cascade on the ordinary tree
(\textit{i.e.} the one without internal degrees of freedom attached to the
vertices) having the same vertex set as the state space of the random walk.
Only results are presented here since the detailed proofs will appear
elsewhere
Computations involving differential operators and their actions on functions
The algorithms derived by Grossmann and Larson (1989) are further developed for rewriting expressions involving differential operators. The differential operators involved arise in the local analysis of nonlinear dynamical systems. These algorithms are extended in two different directions: the algorithms are generalized so that they apply to differential operators on groups and the data structures and algorithms are developed to compute symbolically the action of differential operators on functions. Both of these generalizations are needed for applications
State-of-the-art on evolution and reactivity
This report starts by, in Chapter 1, outlining aspects of querying and updating resources on
the Web and on the Semantic Web, including the development of query and update languages
to be carried out within the Rewerse project.
From this outline, it becomes clear that several existing research areas and topics are of
interest for this work in Rewerse. In the remainder of this report we further present state of
the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give
an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs;
in Chapter 4 event-condition-action rules, both in the context of active database systems and
in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks
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