The methodology presented in this paper is based on concept mapping, which is a technique for representing knowledge in graphs. Its applications are broaderand cover, in addition to presentation of knowledge, the complex organization of systems such as web sites. The paper presents a method for reaching consensus from several organizations of data/web site independently produced by different people. A class of methods was initiated, considering a number of parameters that can be chosen in order to match closely any specificreal-life application. Although the methodology can be fully automated in terms of a suitable computer program, it is meant to be mainly a useful tool for experts in web site organization.

COBISS.SI-ID: 51728482

In the paper we show that the bibliographic data can be transformed into a collection of compatible networks. Using network multiplication different interesting derived networks can be obtained. In defining them an appropriate normalization should be considered. The proposed approach can be applied also to other collections of compatible networks. The networks obtained from the bibliographic data bases can be large (hundreds of thousands of vertices). Fortunately they are sparse and can be still processed relatively fast. We answer the question when the multiplication of sparse networks preserves sparseness. The proposed approaches are illustrated with analyses of collection of networks on the topic "social network" obtained from the Web of Science. The works with large number of co-authors add large complete subgraphs to standard collaboration network thus bluring the collaboration structure. We show that using an appropriate normalization their effect can be neutralized. Among other, we propose a measure of collaborativness of authors with respect to a given bibliography and show how to compute the network of citations between authors and identify citation communities.

COBISS.SI-ID: 16739929

Sierpiński graphs $S_p^n$ form an extensively studied family of graphs of fractal nature applicable in topology, mathematics of the Tower of Hanoi, computer science, and elsewhere. An almost-extreme vertex of $S_p^n$ is introduced as a vertex that is either adjacent to an extreme vertex of $S_p^n$ or is incident to an edge between two subgraphs of $S_p^{n}$ isomorphic to $S_p^{n-1}$. Explicit formulas are given for the distance in $S_p^{n}$ between an arbitrary vertex and an almost-extreme vertex. The formulas are applied to compute the total distance of almost-extreme vertices and to obtain the metric dimension of Sierpiński graphs.

COBISS.SI-ID: 16582233