A Wang tile [12] is a unit square with each edge colored from a finite set of colors Σ. A set S of Wang tiles is said to tile a planar grid Z if copies of tiles from S can be placed, one at each grid position, such that abutting edges of adjacent tiles have the same color. Multiple copies of any tile may be used, with no restriction on the number. If we allow the tiles to be rotated or reflecte...

Algorithmic self-assembly, a generalization of crystal growth processes, has been proposed as a mechanism for autonomous DNA computation and for bottom-up fabrication of complex nanostructures. A ‘program’ for growing a desired structure consists of a set of molecular ‘tiles’ designed to have specific binding interactions. A key challenge to making algorithmic self-assembly practical is designi...

Thanks to a careful study of elementary properties of two-bytwo substitution systems, we give a complete self-contained elementary construction of an aperiodic tile set and sketch how to use this tile set to elementary prove the undecidability of the classical Domino Problem.

Although the design of DNA tiles has been optimised for efficient and specific self-assembly, assembly errors occur so often that applications for molecular computation remain limited. We propose the use of an enveloped tile consisting of a DXbase tile that carries a protector tile to suppress erroneous tile assembly. The design of the enveloped tile promotes the dissociation of the protector t...

The brick ornamentation in Islamic architecture represents the unique skill of the architectural artists and we have seen the perfection of this kind of art during the Seljuk period. There is little information about the process of developing brick art in the architecture of Islamic mosque in Iran, and it has not yet been dealt with as it is worthy of this precious art. Therefore, it is necessa...

This work reports on some useful applications of the tile model to the speciication and execution of CCS-like process calculi. This activity is part of our ongoing research on the relation between tile logic and rewriting logic. 1 Overview Tile Logic 1;2 is a framework for modular descriptions of the dynamic evolution of concurrent systems, extending rewriting logic 3;4 (in the non-conditional ...

this is a field study, tile purpose was to measure and compare the use'. effectiveness and complication of iranian and foreign intra utcrin device ill women who have been using the mentioned method f or birth control ill family planning clinics of the university of medical sciences of iran (/ 993). iii this research by pois son statistical selection, 1620 samples of active record'! oj...

Tiling is a well known loop transformation used to reduce communication overhead in distributed memory machines. Although a lot of theoretical research has been done concerning the selection of proper tile shapes that reduce processor idle times, there is no complete approach to automatically parallelize non-rectangularly tiled iteration spaces and consequently there are no actual experimental ...