40 research outputs found
Limitations of Self-Assembly at Temperature One (extended abstract)
We prove that if a subset X of the integer Cartesian plane weakly
self-assembles at temperature 1 in a deterministic (Winfree) tile assembly
system satisfying a natural condition known as *pumpability*, then X is a
finite union of doubly periodic sets. This shows that only the most simple of
infinite shapes and patterns can be constructed using pumpable temperature 1
tile assembly systems, and gives strong evidence for the thesis that
temperature 2 or higher is required to carry out general-purpose computation in
a tile assembly system. Finally, we show that general-purpose computation is
possible at temperature 1 if negative glue strengths are allowed in the tile
assembly model
Self-Assembly of Infinite Structures
We review some recent results related to the self-assembly of infinite
structures in the Tile Assembly Model. These results include impossibility
results, as well as novel tile assembly systems in which shapes and patterns
that represent various notions of computation self-assemble. Several open
questions are also presented and motivated
Self-assembly of the discrete Sierpinski carpet and related fractals
It is well known that the discrete Sierpinski triangle can be defined as the
nonzero residues modulo 2 of Pascal's triangle, and that from this definition
one can easily construct a tileset with which the discrete Sierpinski triangle
self-assembles in Winfree's tile assembly model. In this paper we introduce an
infinite class of discrete self-similar fractals that are defined by the
residues modulo a prime p of the entries in a two-dimensional matrix obtained
from a simple recursive equation. We prove that every fractal in this class
self-assembles using a uniformly constructed tileset. As a special case we show
that the discrete Sierpinski carpet self-assembles using a set of 30 tiles
Scaled tree fractals do not strictly self-assemble
In this paper, we show that any scaled-up version of any discrete
self-similar {\it tree} fractal does not strictly self-assemble, at any
temperature, in Winfree's abstract Tile Assembly Model.Comment: 13 pages, 3 figures, Appeared in the Proceedings of UCNC-2014, pp
27-39; Unconventional Computation and Natural Computation - 13th
International Conference, UCNC 2014, London, ON, Canada, July 14-18, 2014,
Springer Lecture Notes in Computer Science ISBN 978-3-319-08122-