Antanas Lenkevičius

A simple centerline extraction approach for 2D polygons

T his paper describes a new two task approach for extracting the centerline from simple 2D polygons. An algorithm of the first task, which generates a set of points for future centerline, is presented. The idea of the algorithm is to use the polygon hatching by parallel lines and creating paths from its middle points in different polygon rotations. The centerline is derived from the intersection points between these paths. The algorithm was developed for printed circuit board insulation process and its execution time for a few hundred polygons is less than one second. The algorithm is easy to understand and implement. DOI: http://dx.doi.org/10.5755/j01.itc.45.3.12964

Modified Local Search Heuristics for the Symmetric Traveling Salesman Problem

In this paper, we investigate some modified local search (LS) heuristics for the solution of symmetric traveling salesman problems (TSPs). These modifications are mainly due to the use of extended neighborhood structures. In addition, we are concerned with several new sets of the moves (transitions of solutions) based on the extended configurations of edge exchanges. We are also examining the performance of these extensions being used in an iterated local search (ILS) paradigm. The results from the experiments with the benchmark TSP instances from the TSP library (TSPLIB) demonstrate that the introduced improvements enable to seek solutions of higher quality without substantially increasing computational complexity. DOI: http://dx.doi.org/10.5755/j01.itc.42.3.1301

Issues with exchange of presentation data among CAD systems

Today exchange of data among CAD systems becomes more important. As each CAD system has its own flavor to represent the same objects, exchange of data among them is full of issues. Most common problems are incomplete transfer of presentation information, associativity between representation and presentation, usage of annotation planes and text. They are analyzed in details and possible solutions are suggested as well. DOI: http://dx.doi.org/10.5755/j01.itc.41.4.834