Modelling human network behaviour using simulation and optimization tools: the need for hybridization

The inclusion of stakeholder behaviour in Operations Research / Industrial Engineering (OR/IE) models has gained much attention in recent years. Behavioural and cognitive traits of people and groups have been integrated in simulation models (mainly through agent-based approaches) as well as in optimization algorithms. However, especially the influence of relations between different actors in human networks is a broad and interdisciplinary topic that has not yet been fully investigated. This paper analyses, from an OR/IE point of view, the existing literature on behaviour-related factors in human networks. This review covers different application fields, including: supply chain management, public policies in emergency situations, and Internet-based human networks. The review reveals that the methodological approach of choice (either simulation or optimization) is highly dependent on the application area. However, an integrated approach combining simulation and optimization is rarely used. Thus, the paper proposes the hybridization of simulation with optimization as one of the best strategies to incorporate human behaviour in human networks and the resulting uncertainty, randomness, and dynamism in related OR/IE models.Peer Reviewe

Detecting cyber threats through social network analysis: short survey

This article considers a short survey of basic methods of social networks analysis, which are used for detecting cyber threats. The main types of social network threats are presented. Basic methods of graph theory and data mining, that deals with social networks analysis are described. Typical security tasks of social network analysis, such as community detection in network, detection of leaders in communities, detection experts in networks, clustering text information and others are considered

Trust Management: A Cooperative Approach Using Game Theory

Trust, defined as the willingness to accept risk and vulnerability based upon positive expectations of the intentions or behaviours of another. The qualities or behaviours of one person that create good expectations in another are referred to as trustworthiness. Because of its perceived link to cooperative behaviour, many social scientists regard trust as the backbone of effective social structures. With the advancement in technology, through these online social media people can explore various products, services and facilities. Through these networks the end users want to communicate are usually physically unknown with each other, the evaluation of their trustworthiness is mandatory. Mathematical methods and computational procedures do not easily define trust. Psychological and sociological factors can influence trust. End users are vulnerable to a variety of risks. The need to define trust is expanding as businesses try to establish effective marketing strategies through their social media activities, and as a result, they must obtain consumer trust. Game theory is a theoretical framework for analysing strategic interactions between two or more individuals, in the terminology of game theory, called players. Thus, a conceptual framework for trust evaluation can be designed using a game theory approach that can indicate the conditions under which trustworthy behaviour can be determined

Emergent Communication: The evolution of simplistic machines using different communication types

The methods of transmitting information may be divided as follows: direct; and, indirect. The âdirectâ method occurs when a creature transmits a signal that other creatures in its local environment can receive. Word of mouth advertising is a form of direct communication. âIndirectâ communication relays a message through the environment. This type of communication is known as stigmergy. Both word of mouth communication and stigmergy require the existence of groups of communicators. It is, however, difficult to analyse a very large number of local interactions that occur in group behaviour. A global phenomenon known as âemergenceâ arises from such behaviour. The phrase ââthe whole is greater than the sum of its partsâ normally describes emergence. In this research, we investigate how the two methods of communicating, direct and indirect (including a combination of these), result in emergent behaviour. In order to establish this outcome we employed the use of agent-based software in which we designed groups of agents to evolve over generations in response to specific situations. The manner in which these agent groups evolve is by a genetic algorithm. This is based on the consumption and collection of resources from the environment - a metric for gauging how well the population performs as a whole. For the purpose of this dissertation, we measure and examine the performance of four styles of the two methods of communication: No Communication, Word of Mouth, Stigmergic and Both (a combination of direct and indirect). We observe the fitness arising through successive generations of agents for each of the four styles and compare the results. The âNo Communicationâ style is markedly the worst performer and is âthe sum of the partsâ in terms of the definition of emergence. The âWord of Mouthâ style is marginally below the best performer but is rated well above that of âNo Communicationâ. The âStigmergicâ style is only the third best performer. Combining the direct and indirect methods yields the best result for the âBothâ style. All the communicating categories, considered âthe wholeâ in terms of the definition for emergence, outperform the âNo Communicationâ style. This demonstrates that emergence occurs when using these communication methods in groups. Keywords: Communication, Emergence, Genetic Algorithms, Group Behaviou

A Machine Learning Technique for Detection of Social Media Fake News

publishedVersio

Operational Research IO2017, Valença, Portugal, June 28-30

This proceedings book presents selected contributions from the XVIII Congress of APDIO (the Portuguese Association of Operational Research) held in Valença on June 28–30, 2017. Prepared by leading Portuguese and international researchers in the field of operations research, it covers a wide range of complex real-world applications of operations research methods using recent theoretical techniques, in order to narrow the gap between academic research and practical applications. Of particular interest are the applications of, nonlinear and mixed-integer programming, data envelopment analysis, clustering techniques, hybrid heuristics, supply chain management, and lot sizing and job scheduling problems. In most chapters, the problems, methods and methodologies described are complemented by supporting figures, tables and algorithms. The XVIII Congress of APDIO marked the 18th installment of the regular biannual meetings of APDIO – the Portuguese Association of Operational Research. The meetings bring together researchers, scholars and practitioners, as well as MSc and PhD students, working in the field of operations research to present and discuss their latest works. The main theme of the latest meeting was Operational Research Pro Bono. Given the breadth of topics covered, the book offers a valuable resource for all researchers, students and practitioners interested in the latest trends in this field.info:eu-repo/semantics/publishedVersio

Computational intelligent methods for trusting in social networks

104 p.This Thesis covers three research lines of Social Networks. The first proposed reseach line is related with Trust. Different ways of feature extraction are proposed for Trust Prediction comparing results with classic methods. The problem of bad balanced datasets is covered in this work. The second proposed reseach line is related with Recommendation Systems. Two experiments are proposed in this work. The first experiment is about recipe generation with a bread machine. The second experiment is about product generation based on rating given by users. The third research line is related with Influence Maximization. In this work a new heuristic method is proposed to give the minimal set of nodes that maximizes the influence of the network