Identification of Group Changes in Blogosphere

The paper addresses a problem of change identification in social group evolution. A new SGCI method for discovering of stable groups was proposed and compared with existing GED method. The experimental studies on a Polish blogosphere service revealed that both methods are able to identify similar evolution events even though both use different concepts. Some differences were demonstrated as wellComment: The 2012 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining, IEEE Computer Society, 2012, pp. 1233-123

Predicting Community Evolution in Social Networks

Nowadays, sustained development of different social media can be observed worldwide. One of the relevant research domains intensively explored recently is analysis of social communities existing in social media as well as prediction of their future evolution taking into account collected historical evolution chains. These evolution chains proposed in the paper contain group states in the previous time frames and its historical transitions that were identified using one out of two methods: Stable Group Changes Identification (SGCI) and Group Evolution Discovery (GED). Based on the observed evolution chains of various length, structural network features are extracted, validated and selected as well as used to learn classification models. The experimental studies were performed on three real datasets with different profile: DBLP, Facebook and Polish blogosphere. The process of group prediction was analysed with respect to different classifiers as well as various descriptive feature sets extracted from evolution chains of different length. The results revealed that, in general, the longer evolution chains the better predictive abilities of the classification models. However, chains of length 3 to 7 enabled the GED-based method to almost reach its maximum possible prediction quality. For SGCI, this value was at the level of 3 to 5 last periods.Comment: Entropy 2015, 17, 1-x manuscripts; doi:10.3390/e170x000x 46 page

Modelling Agents Cooperation Through Internal Visions of Social Network and Episodic Memory

Human societies appear in many types of simulations. Particularly, a lot of new computer games contain a virtual world that imitates the real world. A few of the most important and the most difficult society elements to be modelled are the social context and individuals cooperation. In this paper we show how the social context and cooperation ability can be provided using agents that are equipped with internal visions of mutual social relations. Internal vision is a representation of social relations from the agent's point of view so, due to being subjective, it may be inconsistent with the reality. We introduce the agent model and the mechanism of rebuilding the agent's internal vision that is similar to that used by humans. An experimental proof of concept implementation is also presented

A PROPOSITION OF KNOWLEDGE MANAGEMENT METHODOLOGY FOR THE PURPOSE OF REASONING WITH THE USE OF AN UPPER-ONTOLOGY

This article describes a proposition of knowledge organization for the purpose of reasoningusing an upper-ontology. It presents a model of integrated ontologies architecture whichconsists of a domain ontologies layer with instances, a shared upper-ontology layer withadditional rules and a layer of ontologies mapping concrete domain ontologies with the upperontology.Thanks to the upper-ontology, new facts were concluded from domain ontologiesduring the reasoning process. A practical realization proposition is given as well. It is basedon some popular SemanticWeb technologies and tools, such as OWL, SWRL, nRQL, Prot´eg´eand Racer

Multi-Agent Environment for Modelling and Solving Dynamic Transport Problems

The transport requirements in modern society are becoming more and more important. Thus, offered transport services need to be more and more advanced and better designed to meet users demands. Important cost factors of many goods are transport costs. Therefore, a reduction of costs, a better adjustment of strategies to the demand as well as a better planning and scheduling of available resources are important for the transport companies. This paper is aimed at modelling and simulation of transport systems, involving a dynamic Pickup and Delivery problem with Time Windows and capacity constraints (PDPTW). PDPTW is defined by a set of transport requests which should be performed while minimising costs expressed by the number of vehicles, total distance and total travel time. Each request is described by two locations: pickup and delivery, periods of time when the operations of pickup or delivery can be performed and a load to be transported. The nature of this problem, its distribution and the possibility of using a lot of autonomous planning modules, lead us to use a multi-agent approach. Our approach allows the modeling of entities which do not appear in the classical PDPTW such as company organisation, communication among vehicles, interactions between vehicles and company dispatcher or different strategies of requests acceptation by different vehicles. This paper presents also a software environment and experimentations to validate the proposed approach

Identyfikacja wzorców w ruchu drogowym metodą częstych sekwencji

Tyt. z nagłówka.Bibliogr. s. 270.Dostępny również w formie drukowanej.STRESZCZENIE: Artykuł dotyczy analizy wzorców danych dotyczących stanu ruchu pojazdów. W szczególności skupiono się na analizie częstych sekwencji. Analizowane dane zostały pozyskane w oparciu o wieloagentowy symulator do modelowania i optymalizacji ruchu drogowego. SŁOWA KLUCZOWE: ruch drogowy, wzorce, częste sekwencje. ABSTRACT: The paper concerns the analysis of data about road traffic. We are focusing our analysis on the frequent sequences. The analysed data was obtained using multi-agent simulator for modelling and optimisation of road traffic. KEYWORDS: road traffic, patterns, frequent sequences

Urban Railways as a Basis of Transport Systems in Metropolitan Areas in Poland

The dynamic development of metropolitan areas in Poland poses increasing challenges for organization of transport systems. A spatial expansion of metropolis and a separation of places of residence from work and services increase the mobility of society. An excessive development of motorization and low competitiveness of public transport cause chronic congestion in the road network of metropolitan areas. In such a situation, the best solution can be railways integrated with an urban public transport and Park & Ride infrastructure near train stations in the suburbs