Tag-based modules in genetic programming

In this paper we present a new technique for evolving mod-ular programs with genetic programming. The technique is based on the use of “tags ” that evolving programs may use to label and later to refer to code fragments. Tags may refer inexactly, permitting the labeling and use of code fragments to co-evolve in an incremental way. The technique can be implemented as a minor modification to an existing, general purpose genetic programming system, and it does not re-quire pre-specification of the module architecture of evolved programs. We demonstrate that tag-based modules readily evolve and that this allows problem solving effort to scale well with problem size. We also show that the tag-based module technique is effective even in complex, non-uniform problem environments for which previous techniques per-form poorly. We demonstrate the technique in the context of the stack-based genetic programming system PushGP, but we also briefly discuss ways in which it may be used with other kinds of genetic programming systems

Algorithmic Comparison of "Shamsah" in Iranian Architecture, Carpet and Pottery

During various art periods of Iran, three art fields of pottery, architectural decorations and carpet weaving have had a significant contribution to the artistic trends of the Islamic period. The purpose of the present research was to explain and analyze the geometric patterns used in the Islamic artworks of pottery, architecture and carpet weaving and the influence of these three fields of art on each other. Other research objectives were also to examine the common features of above-mentioned fields of art in order to provide a schematic model based on their artistic nature. The main question of the present research were as follows: 1.What are the common features of Shamsah, in terms of geometric shape, in the three above-mentioned fields of art, given their different historical intervals and art periods? 2. How is it possible to achieve similar shapes through changing the geometrical parameters in the mathematical algorithm of these Shamsah? This research was conducted using a comparative-analytical approach. Data were collected using desk studies – due to the research literature – and field studies – because of observing and taking pictures of some decorations in three above-mentioned fields of art. Finally, computer simulation was used to do data analysis. The results of this study indicated that the principles of composition of geometric patterns in the three studied fields of art were based on the order, arrangement and organization of motifs to achieve a coherent format. &nbsp