Darko Grundler

Minimizing environmental electromagnetic field pollution adjusting transmitter parameters using genetic algorithm

Paper describes method for finding transmitter parameters (location and power) for optimal electromagnetic radiation distribution in observed area. Constrains are protected areas inside observed area where strength of electric field is limited because of permanent people presence. In observed area one wish to obtain strength of electric field which is higher than lower limit value to cover the area with enough reception signal strength. On the other side electric field inside protected areas has to be lower than prescribed upper limit. Those two conditions are contradictory. In here described investigation genetic algorithm is used to find transmitter parameters (location and power) constrained by above mentioned conditions. Main purpose of investigations is examining applicability of procedure. Initial investigation is limited to rectangular planar observing area with one transmitter and with different formation and size of protected areas (areas in which strength of electric field is limited because of permanent people presence). Procedure has been repeated and results statistically analyzed. Based on those results it can be concluded that procedure is applicable and it is justified to continue investigations for more complex and more realistic situations e.g. more transmitters with directed radiations and for three dimensional spaces.

Evolutionary algorithms aided textile design

Fabric design has always been a matter of inspiration, depending mostly upon mans ingenuity and creativity. The authors suggest that creation of fabric patterns using evolution algorithms, which can not only help in improving design created by man, but also make the procedure semi‐automatic, meaning much less dependent upon the designer himself/herself. Evolution algorithm based software offers a wide range of fabric patterns and is also able to create new ones based on the users choice. The procedure can also be of considerable help to professional designers, as it can offer patterns they would not or could not create themselves. The system described is inexpensive and can be used on IBM compatible personal computers. It is user‐friendly and can be implemented with no previous preparation on the part of the user. The results of preliminary investigations suggest a practical applicability of the software.

Algorithms for 2D nesting problem based on the no-fit polygon

Strip-packing problem is apparent in textile industry where a set of items, i.e. cutting parts (2D convex or non-convex polygons) need to be placed on a rectangular container (fabric with an mxn area) so that cutting parts do not overlap and do not exceed the boundaries of the container. The goal is to find a placement that utilizes the area of a container. In this paper three methods (random search, greedy algorithm and genetic algorithm) are tested on sets of regular (convex polygons) and irregular (cutting parts) items. The goal is to find the optimal items placement that minimizes the cover area. In this paper a no-fit polygon (NFP) is used to assure two items touch without overlapping. NFP is constructed by rotating polygon B around a static polygon A in a way their edges always touch and never overlap. The result is a polygonal area enclosed by trajectory of rotating polygons reference point which represents the overlapping area of A and B. Items touch if polygon B is placed on the NFPs border. Non-convex cutting parts are approximated with their convex hull since a NFP version for convex polygons is used in this paper.

Genetic algorithm based reduction of electromagnetic field pollution

Paper describes a method for finding transmitter parameters (location, power and horizontal direction) for optimal electromagnetic radiation distribution in the observed area. Constraints are protected areas inside the observed area where strength of electric field is limited because of a permanent people presence. In the observed area one wishes to obtain the strength of electric field which is higher than the lower limit value to cover the area with enough reception signal power. On the other hand electric field inside protected areas has to be lower than the prescribed upper limit determined by a health hazard. These two conditions are contradictory. In this investigation a genetic algorithm is used to find transmitter parameters (location, power and horizontal direction) constrained by above mentioned conditions. Investigation is limited to a rectangular planar observing area with one transmitter and with different formation and size of protected areas. The procedure has been repeated for 15 times and the results are analyzed statistically. Based on these results it can be concluded that the procedure is applicable and it is justified to continue investigations for more complex and more realistic situations, e.g. more than one transmitter with directed radiations and for 3D spaces.