11,895 research outputs found
How the Dimension of Space Affects the Products of Pre-Biotic Evolution: The Spatial Population Dynamics of Structural Complexity and The Emergence of Membranes
We show that autocatalytic networks of epsilon-machines and their population
dynamics differ substantially between spatial (geographically distributed) and
nonspatial (panmixia) populations. Generally, regions of spacetime-invariant
autocatalytic networks---or domains---emerge in geographically distributed
populations. These are separated by functional membranes of complementary
epsilon-machines that actively translate between the domains and are
responsible for their growth and stability. We analyze both spatial and
nonspatial populations, determining the algebraic properties of the
autocatalytic networks that allow for space to affect the dynamics and so
generate autocatalytic domains and membranes. In addition, we analyze
populations of intermediate spatial architecture, delineating the thresholds at
which spatial memory (information storage) begins to determine the character of
the emergent auto-catalytic organization.Comment: 9 pages, 7 figures, 2 tables;
http://cse.ucdavis.edu/~cmg/compmech/pubs/ss.ht
Efficient and Reasonable Object-Oriented Concurrency
Making threaded programs safe and easy to reason about is one of the chief
difficulties in modern programming. This work provides an efficient execution
model for SCOOP, a concurrency approach that provides not only data race
freedom but also pre/postcondition reasoning guarantees between threads. The
extensions we propose influence both the underlying semantics to increase the
amount of concurrent execution that is possible, exclude certain classes of
deadlocks, and enable greater performance. These extensions are used as the
basis an efficient runtime and optimization pass that improve performance 15x
over a baseline implementation. This new implementation of SCOOP is also 2x
faster than other well-known safe concurrent languages. The measurements are
based on both coordination-intensive and data-manipulation-intensive benchmarks
designed to offer a mixture of workloads.Comment: Proceedings of the 10th Joint Meeting of the European Software
Engineering Conference and the ACM SIGSOFT Symposium on the Foundations of
Software Engineering (ESEC/FSE '15). ACM, 201
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