Graph-Theoretic Concepts in Computer Science, 43rd International Workshop, WG 2017, Eindhoven, The Netherlands, June 21-23, 2017, Revised Selected Papers
This book constitutes the revised selected papers of the 43rd International Workshop on Graph-Theoretic Concepts in Computer Science, WG 2017, held in Eindhoven, The Netherlands, in June 2017.
The 31 full papers presented in this volume were carefully reviewed and selected
from 71 submissions. They cover a wide range of areas, aiming at connecting theory and applications by demonstrating how graph-theoretic concepts can be applied in various areas of computer science. Another focus is on presenting recent results and on identifying and exploring promising directions of future research.
Weighted independent domination is an NP-hard graph problem, which remains computationally intractable in many restricted graph classes. Only few examples of classes are available, where the problem admits polynomial-time solutions. In the present paper, we extend the short list of such classes with two new examples.
A hypergraph is Sperner if no hyperedge contains another one. A Sperner hypergraph is equilizable (resp., threshold) if the characteristic vectors of its hyperedges are the (minimal) binary solutions to a linear equation (resp., inequality) with positive coefficients. These combinatorial notions have many applications and are motivated by the theory of Boolean functions and integer programming. We introduce in this paper the class of 1-Sperner hypergraphs, defined by the property that for every two hyperedges the smallest of their two set differences is of size one. We characterize this class of Sperner hypergraphs by a decomposition theorem and derive several consequences from it. In particular, we obtain bounds on the size of 1-Sperner hypergraphs and their transversal hypergraphs, show that the characteristic vectors of the hyperedges are linearly independent over the reals, and prove that 1-Sperner hypergraphs are both threshold and equilizable. The study of 1-Sperner hypergraphs is motivated also by their applications in graph theory, which we present in a companion paper.
The paper is devoted to the usage of the visual analytics methods and means for systematiс exploration of the results of a multi-parameter data of social Web-based service users. These data include language characteristics of the users’ comments and posts obtained from the social services they use, as well as psychological and social characteristics obtained from their profiles and from the results of surveys they fulfilled. Suggested visual analytics tools enable to present the correlations between different users’ characteristics in an observable form and to help proposing and testing hypotheses without repeating the initial data processing experiment, using just visual analytics tools to produce new results. This in turn enables to uncover and study the regularities in the input data. Semograph linguistic analysis software is suggested as a tool to collect and preprocess the data. SciVi ontology-driven multiplatform adaptive scientific visualization system is proposed to be a visual analytics tool. Because the input data have a lot of interconnections, the described visual analytics tools are based on a graph data representation model. Circular graph with adjustable hierarchical ring scale and free structured graph are supported within SciVi to ensure advanced visual analytics. The paper presents the main interactive features and implementation details of suggested tools. In particular, different filtering mechanisms for nodes and arcs are presented, as well as the means to navigate through different input data slices. The implemented visual analytics tools are tested by solving the real world problems related to the results of psychological surveys. The survey was conducted among the users of VKontakte social network. The dependencies between their psychological characteristics and verbal behavior are discovered.
The approaches based on applying of metamodeling and domain-specific languages are widely used in software engineering. There are many different tools for creating visual domain-specific modeling languages with a possibility of determining user’s graphical notations. However, these tools possess disadvantages. The article presents an approach to the development of language workbench that allows to eliminate some restrictions of existing DSM-platforms. The MetaLanguage system is designed for creation of visual dynamic adaptable domain-specific modeling languages and for models construction with these languages. It allows executing transformations of the created models in various textual and graphical notations. Basic metalanguage constructions of this system are described. The formal description of modeling languages metamodel used in MetaLanguage is given. The architecture of MetaLanguage toolkit is presented.
We describe a novel game-theoretic formulation of the optimal mobile agents’ placement problem which arises in the context of Mobile Ad-hoc Networks (MANETs). This problem is modelled as a sequential multistage game. The definitions of both the Nash equilibrium and cooperative solution are given. A modification was proposed to ensure the existence of a Nash equilibrium. A modelling environment for the analysis of different strategies of the players was developed in MATLAB. The programme generates various game situations and determines each player move by solving respective optimisation problems. Using the developed environment, two specific game scenarios were considered in detail. The proposed novel algorithm was implemented and tested using Network Simulator 3 (NS-3). The results show that the proposed novel algorithm increases network performance by using game theory principles and techniques.
The paper proposes morphological models for the analysis of complex electronic systems quality criterion. The reason for resorting to morphological models is the need to increase attention to improving the quality and reliability of electronic systems in the early design stages. At the same time, many difficulties of mathematical modeling of the investigated heterogeneous physical processes occurring in electronic systems are solved. In this paper, the unification of the notation and the image of components based on analogies of mathematical descriptions. In linear synthesis morphological models in the form of connection of multipolar systems are offered. But they allow you to explore the electrical, mechanical and thermal processes only in linear approximation. In contrast to this representation, the paper also proposes unified view of morphological models in the form of a hypergraph, which will cover nonlinear cases.
In this article we use the modular decomposition technique for exact solving the weighted maximum clique problem. Our algorithm takes the modular decomposition tree from the paper of Tedder et. al. and finds solution recursively. Also, we propose algorithms to construct graphs with modules. We show some interesting results, comparing our solution with Ostergards algorithm on DIMACS benchmarks and on generated graphs.
This proceedings publication is a compilation of selected contributions from the “Third International Conference on the Dynamics of Information Systems” which took place at the University of Florida, Gainesville, February 16–18, 2011. The purpose of this conference was to bring together scientists and engineers from industry, government, and academia in order to exchange new discoveries and results in a broad range of topics relevant to the theory and practice of dynamics of information systems. Dynamics of Information Systems: Mathematical Foundation presents state-of-the art research and is intended for graduate students and researchers interested in some of the most recent discoveries in information theory and dynamical systems. Scientists in other disciplines may also benefit from the applications of new developments to their own area of study.
A form for an unbiased estimate of the coefficient of determination of a linear regression model is obtained. It is calculated by using a sample from a multivariate normal distribution. This estimate is proposed as an alternative criterion for a choice of regression factors.