Scaling Subgraph Matching by Improving Ullmann Algorithm

Graphs are widely used to model complicated data semantics in many application domains. Subgraph isomorphism checking (an NP-complete problem) is a regular operation with this kind of data. In this paper, we propose an improvement of Ullmann algorithm, a well-known subgraph isomorphism checker. Our new algorithm is called Ullmann-ONL. It utilizes a new search ordering and L-levels of vertex neighborhoods (NL) to confine the search space of Ullmann algorithm. Our performance study shows that Ullmann-ONL outperforms previously proposed algorithms with a wide margin

Digitális írástudás, digitális nyelvhelyesség

L

Design informatics special workgroup in view of learner’s fields of interest is secondary schools of Transcarpathia

E-learning can be used in many areas of education from higher education, company training to elementary schools. We examined the secondary school education, because this area is not sufficiently developed for the modern information society. We have to find practical methods to blend the means of e- learning and traditional education. Our motivations for creating a special workgroup on information technology (IT) is to mitigate the problems caused by the following: • in Transcarpathian IT classroom’s equipments are outdated and cannot serve quantitative and qualitative hardware and software for students, • the actual IT workgroups are not enough interesting for the students because their curricula are not adapted to the pupils IT skills. Our aim is to design IT workgroups using blended learning [7]. To achieve this goal, we examine the students’ IT skills by using Galois lattices [5]. We use learning management system to connect learners and teachers in a virtual learning environment. Among free LMS systems we are focused on those systems that are the most usable, suitable and motivating in secondary school education and have friendly interfaces. Our aim in teaching methodology is to develop the following skills: self-study, digital literacy, collaborative group work. Keywords: blended learning, adapted education, teaching in Transcarpathia, IT workgroups