2-semiarcs in PG(2, q), q <= 13

A 2-semiarc is a pointset S-2 with the property that the number of tangent lines to S-2 at each of its points is two. Using some theoretical results and computer aided search, the complete classification of 2-semiarcs in PG(2, q) is given for q <= 7, the spectrum of their sizes is determined for q <= 9, and some results about the existence are proven for q = 11 and q = 13. For several sizes of 2-semiarcs in PG(2, q), q <= 7, classification results have been obtained by theoretical proofs

PLANNING TECHNOLOGIES FOR THE WEB ENVIRONMENT: PERSPECTIVES AND RESEARCH ISSUES

РАН, Российский университет дружбы народов, Российская ассоциация искусственного интеллекта, Москва

The Pace code, the Mathieu group M \u3c inf\u3e 12 and the small Witt design S(5,6,12)

© 2017 Elsevier B.V. A ternary [66,10,36]3-code admitting the Mathieu group M12 as a group of automorphisms has recently been constructed by N. Pace, see Pace (2014). We give a construction of the Pace code in terms of M12 as well as a combinatorial description in terms of the small Witt design, the Steiner system S(5,6,12). We also present a proof that the Pace code does indeed have minimum distance 36

Task Planning and Partial Order Planning: A Domain Transformation Approach

1 Introduction In the last years many papers have dealt with Hierarchical Task Network (HTN) approach in AI planning ([15],[7],[5],[8],[6]). The success of this approach is due to its effectiveness from both the expressivity and computational sides. The works of Yang [15], Erol et al.[5] [7] and Kambhampati [10] have extensively investigated semantics and complexity of this approach. They show that HTN is strictly more powerful than ordinary (STRIPS-like) planning. This result basically derives from the fact that the set of solution plans of an ordinary planning problem is a regular language, while the set of solution plans of HTN planning problems is a higher level language, (i.e. the solutions space can be expressed as intersection of context free languages)