Difference between revisions of "Zig-Zag Systems"
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==Zig-Zag Tile Assembly Systems== | ==Zig-Zag Tile Assembly Systems== | ||
| − | A tile assembly system T = (T, | + | A tile assembly system $\mathcal{T} = (T, \sigma, 2)$ is called a zig-zag tile assembly system if (1) $\mathcal{T}$ is directed, (2) there is a single assembly sequence $\vec{\alpha}$ in $\mathcal{T}$ , with $A_t[\mathcal{T}] = {\alpha}$, and (3) for every $\vec{x} \in$ dom $\alpha$, (0, 1) $\notin $IN$^{\vec{\alpha}} (\vec{x})$. Intuitively, zig-zag systems are those that grow one horizontal row at a time, alternating left-to-right and right-to-left growth, always adding new rows to the north and never growing south. Zig-zag systems are capable of simulating universal Turing machines, and thus universal computation. If $\mathcal{T}$ is a zig-zag system with $A_t[\mathcal{T}] = {\alpha}$ and for every $\vec{x} \in$ dom $\alpha$ and every $\vec{u} \in U_2,$ $str_{α(\vec{x})}(\vec{U})$ + $str_{α(\vec{x})}(-\vec{U})$ < 4, then we say that $\mathcal{T}$ is compact. Intuitively, compact zig-zag systems are zig-zag systems that only extend the width of each row by one over the length of the previous row, and only grow upward by one tile before continuing horizontal growth. Compact zig-zag systems are capable of simulating universal Turing machines. <ref name="NegaGlue"/> |
| + | |||
| + | ==References== | ||
| + | |||
| + | <references> | ||
| + | <ref name="NegaGlue"><bibtex> | ||
| + | @article{NegaGlue, | ||
| + | author = "Matthew J. Patitz, Robert T. Schweller, Scott M. Summers", | ||
| + | title = "Efficient Squares and Turing Universality at Temperature 1 with a Unique Negative Glue", | ||
| + | journal = "arXiv", | ||
| + | number = "1105.1215", | ||
| + | year = "2012", | ||
| + | } | ||
| + | </bibtex></ref> | ||
| + | </references> | ||
| + | |||
| + | [[category:Tile Assembly Models]] | ||
| + | [[Category:Self-assembly]] | ||
Revision as of 10:58, 6 July 2016
Zig-Zag Tile Assembly Systems
A tile assembly system \(\mathcal{T} = (T, \sigma, 2)\) is called a zig-zag tile assembly system if (1) \(\mathcal{T}\) is directed, (2) there is a single assembly sequence \(\vec{\alpha}\) in \(\mathcal{T}\) , with \(A_t[\mathcal{T}] = {\alpha}\), and (3) for every \(\vec{x} \in\) dom \(\alpha\), (0, 1) \(\notin \)IN\(^{\vec{\alpha}} (\vec{x})\). Intuitively, zig-zag systems are those that grow one horizontal row at a time, alternating left-to-right and right-to-left growth, always adding new rows to the north and never growing south. Zig-zag systems are capable of simulating universal Turing machines, and thus universal computation. If \(\mathcal{T}\) is a zig-zag system with \(A_t[\mathcal{T}] = {\alpha}\) and for every \(\vec{x} \in\) dom \(\alpha\) and every \(\vec{u} \in U_2,\) \(str_{α(\vec{x})}(\vec{U})\) + \(str_{α(\vec{x})}(-\vec{U})\) < 4, then we say that \(\mathcal{T}\) is compact. Intuitively, compact zig-zag systems are zig-zag systems that only extend the width of each row by one over the length of the previous row, and only grow upward by one tile before continuing horizontal growth. Compact zig-zag systems are capable of simulating universal Turing machines. [1]
References
- ↑
Matthew J. Patitz, Robert T. Schweller, Scott M. Summers - Efficient Squares and Turing Universality at Temperature 1 with a Unique Negative Glue
