Jaroslaw Kozlak

Different approaches to community evolution prediction in blogosphere

Predicting the future direction of community evolution is a problem with high theoretical and practical significance. It allows to determine which characteristics describing communities have importance from the point of view of their future behaviour. Knowledge about the probable future career of the community aids in the decision concerning investing in contact with members of a given community and carrying out actions to achieve a key position in it. It also allows to determine effective ways of forming opinions or to protect group participants against such activities. In the paper, a new approach to group identification and prediction of future events is presented together with the comparison to existing method. Performed experiments prove a high quality of prediction results. Comparison to previous studies shows that using many measures to describe the group profile, and in consequence as a classifier input, can improve predictions.

An Evolutionary Approach to Pickup and Delivery Problem with Time Windows

Recently, the quality and the diversity of transport services are more and more required. Moreover, in case of a great deal of services and selling goods, a significant part of price is transport cost. Thus, the design of models and applications which make possible efficient transport planning and scheduling becomes important. A great deal of real transport problems may be modelled by using Pickup and Delivery Problem with Time Windows (PDPTW) and capacity constraints, which is based on the realization of a set of transport requests by a fleet of vehicles with given capacities. Each request is described by pickup and delivery locations, time periods when pickup and delivery operations should be performed and needed load. Application of evolutionary approach has brought good results in case of another, simpler transport problem – the Vehicle Routing Problem with Time Windows (VRPTW). This paper is aimed at proposing a straightforward extension of VRPTW based heuristics for the PDPTW.

Multi-agent Environment for Dynamic Transport Planning and Scheduling

Nowadays, transport requests of the society are becoming more and more common and important. Computer systems may be a useful tool for transport companies. This paper is aimed at presenting a system which simulates the functioning of a transport company. The theoretical problem, which needs to be solved, is a dynamic Pickup and Delivery Problem with Time Windows and capacity constraints (PDPTW). The nature of the problem, its distribution and the possibility of using a lot of autonomous planning modules, predestines to apply a multi-agent approach. Multi-agent approach facilitates the introduction of elements which do not appear in classical PDPTW as company organisation, different strategies of requests acceptation by different vehicles or communication among vehicles.

Multi-agent System for Flexible Manufacturing Systems Management

The paper focuses on the application of a multi-agent system for a management process. The presented system is working on the structure of graph, where nodes represent decision modules and edges - technological processes. Kinds of agents working in such environment are presented and an overview of the interaction protocols which can be used in such a system is given.

Agent-based Modelling of Social Organisations

In the paper, the model of the society represented by a social network and the model of a multi-agent system built on the basis of this, is presented. The particular aim of the system is to predict the evolution of a society and an analysis of the communities that appear, their characteristic features and reasons for coming into being. As an example of application, an analysis was made of a social portal which makes it possible to offer and reserve places in rooms for travelling tourists.

Highlights of Practical Applications of Heterogeneous Multi-Agent Systems. The PAAMS Collection

This book constitutes the refereed proceedings of the workshops which complemented the 12th International Conference on Practical Applications of Agents and Multi-Agent Systems, PAAMS 2014, held in Salamanca, Spain, in June 2014. This volume presents the papers that have been accepted for the following workshops: Workshop on Agent-based Approaches for the Transportation Modeling and Optimization (AATMO 2014); Workshop on Agent-based Modeling and Simulation of Complex Systems: Engineering and Applications (ABSEA 2014); Workshop on Agents and Multi-Agent Systems for Ambient-assisted Living and e-Health (A-HEALTH 2014); Workshop on Agent-based Solutions for Manufacturing and Supply Chain (AMSC 2014); Workshop on Intelligent Systems for Context-based Information Fusion (ISCIF 2014); Workshop on Multi-Agent based Applications for Smart Grids and Sustainable Energy Systems (MASGES 2014); Workshop on Active Security Through Multi-Agent Systems (WASMAS 2014); Workshop on Intelligent Human-Agent Societies (WIHAS 2014).

Different Approaches to Groups and Key Person Identification in Blogosphere

Two approaches for identifying key persons in the blogosphere-based social network are analysed in the paper: discovery of the most important individuals either in persistent or in global social communities existing on web blogs. A new method for the separation of stable groups fulfilling given conditions is presented. Additionally, a new concept for extraction of user roles and key persons in such groups is proposed. It has been compared to the general clustering method and structural node position measure applied to rank users in the time-aggregated data. Experimental, comparative studies have been conducted on real blogosphere data gathered over one year.

Modeling Agent Organizations

We present a formal specification of an environment created by our mobile platform Pegaz [17]. Since all existing mobile agent platform create more or less the same infrastructure on a computer network, this formal specification may be seen as a formal representation of the cyberspace Then, we present a concept of agent organizations in a model of production environment. It is argued that such organizations can be applied in the cyberspace. Agents are supposed to form enterprises producing the commodity specified by the system designer, and then sell the commodity at the market. The goal of the designer is to create efficient enterprises producing the desired commodity. The market is modeled as the price oligopoly. The price oligopoly serves to eliminate enterprises that are not efficient.

Agent Approach for Transportation Modelling and Optimisation

Abstract The goal of the work is to develop a multi-agent model and then a system, which makes it possible to solve different kinds of transportation problems. The work will be compared with several multi-agent methodologies. A general multi-agent model and other specific models which make it possible to solve different transport problems are described. The paper also contains a presentation of a pilot realisation including a selection of the subsequent results obtained during experiments.

Agent environment for supply chain modelling and management

Abstract In this paper, a model of a multi-agent system for modelling and optimising supply chains will be presented. The most popular methodologies of developing multi-agent systems and selected applications of the agent approach to modelling and optimisation of supply chains is described in brief. We also present a pilot realisation of such a system, together with a selection of the subsequent experimental results obtained.