Opening Session - Chair: Prof. Dr. Graçaliz Dimuro

Research Projects/Groups Session - Chair: Prof. Dr. Graçaliz Dimuro

Technical Session 1 - Chair: Prof. Dr. Diana Adamatti

1. Elementary Social Functions: Concept and Interrelation to Social Dependence Relations

Antonio Carlos da Rocha Costa, Gracaliz Dimuro, Universidade Federal do Rio Grande, Brazil.

Abstract. This paper introduces a general notion of elementary systemic functions and shows how elementary systemic functions can be instantiated as elementary social functions in agent societies, thus allowing for a functional view of agent interactions. The paper shows a way to interrelate elementary social functions and social dependence relations, for social dependence relations determined by maintenance goals. Also, the paper introduces the notions of elementary functional cycles and elementary functional networks, with functional cycles constituting the operational bases of functional networks, and shows how such structures interrelate to social dependence networks. An example social system is analysed from this elementary functional point of view. Starting from its social dependence network, an elementary functional network is determined for such system. The distinction between elementary social functions and maintenance goals is emphasized in the analysis of the example.

2. How Coalitions Enhance Cooperation in the IPD over Complex Networks

Ana Peleteiro, Univ. Vigo, Spain;Juan Carlos Burguillo, Univ. Vigo, Colombia;Ana Bazzan, UFRGS, Brazil.

Abstract. Grouping into coalitions can be an important way of coop- eration through which multi-agent systems (MAS) improve their perfor- mance, accomplish their assignments, increase their benets and achieve their goals. However, agents belonging to a coalition must decide how they behave to increase their gains. In this paper, we present a model that combines learning and coalitions to enhance cooperation over the social Iterated Prisoner''s Dilemma (IPD). We focus on agents interact- ing over complex networks since they provide a realistic model of the nowadays interconnected world. Our results suggest that coalitions are a relevant contribution to achieve cooperation in the social IPD.

12:15 - 12:30

BWSS 2012 – Remote Presentation

1. Comparing complex networks: An application to emergency managers mental models

Nuno Caseiro, IPCB, Portugal; Paulo Trigo, Instituto Superior de Engenharia de Lisboa, Portugal.

Abstract. This paper describes an exploratory work that aims to identify a semantic basis underlying the mental model from the field of emergency management using a collaborative approach. The data was obtained, by surveying a group of Civil protection graduates and aggregating all the answers. The data allowed us to deepen the analysis of the resulting network as to understand the main group concepts and their relations in this domain. An experimental application of the distance ratio was used to compare indi-vidual networks among them to analyze the aggregated network representing the group mental model.

Lunch time

Invited Talk 1: Dr. Armando Geller, chair: Prof. Dr. Antônio Carlos Costa

Coffee Break

Technical Session 3 - Chair: Prof. Dr. Jaime Sichman

1. Replicating Hofstede's Cultured Negotiation: A First Update

João Maria Graça, Faculdade de Psicologia da Universidade de Lisboa, Portugal; Helder
Coelho, Universidade de Lisboa, Portugal.

Abstract. Hofstede et al. cultured negotiating agents simulation produced realistic behavior by incorporating Hofstede''s dimensional model of culture in the agent''s negotiation protocol and overall behavior. Given such a promising model to generate actual human-like behavior in artificial agents, and the lack of sound and well accepted replication methodologies, we reviewed our original replication research: the parameters sensitivity test replication, a new real countries indices simulation replication, the roadblocks encountered during the process and the suggestions in order to avoid such obstacles. New results continue to show a relational equivalence.

2. A Study on Socio-Spatial Segregation Models Based on Multi-Agent Systems

Tauã Cabreira, Carlos Quadros, Felipe da Silva,  Josimara Silveira,  Liliane Antiqueira, Suvania
Oliveira, Stephanie Brião,  Leonardo M. Rodrigues, Universidade Federal do Rio Grande, Brazil.

Abstract. This work studies the modeling Socio-Spatial Segregation. This phenomenon occurs, most often, unintentionally in some cities, especially in large population centers. Multi-agent simulation is adopted using the NetLogo software. From an existing template available in the models library, we developed some examples with variations for the basic case of social classes'' segregation.

3. Analyzing the Evolution of Social Exchange Strategies in Social Preference-based MAS through an Evolutionary Spatial Approach of the Ultimatum Game

Luís Felipe de Macedo, Universidade Federal de Rio Grande, Brazil; Gracaliz Dimuro, Universidade Federal
do Rio Grande, Brazil; Marilton de Aguiar, UFPel, Brazil; Antonio Carlos da Rocha Costa, FURG, Brazil;
Helder Coelho, Universidade de Lisboa, Portugal; Viviane Leite Dias de Mattos, Universidade Federal do Rio
Grande, Brazil.

Abstract. This paper presents a multiagent-based approach of an evolutionary and spatial version of the Ultimatum Game interpreted as Game of Social Exchange Process, where the agents organized in a complex network evolve their exchange strategies considering their possibly different social preferences. We analyze the possibility of the emergence of the equilibrium/fairness behavior when the agents, trying to maximize their social preference-based utility functions, increase the number of successful interactions. We consider a incomplete information game, since the agents do not have information about the other agents'' exchange strategies. For the strategy learning process, a genetic algorithm is used, where the agents aiming at the self-regulation of the exchanges allowed by the game, balance individual and collective goals expressed by their social preferences. We also analyze a second type of scenario, considering an influence politics, when the average of the offer and reserve values of all agents adopting the same social preference form becomes public in a single simulation step, and the agents of the same network, been influenced by that, imitate those values. At the same time, the network topology is modified, representing some kind of mobility, in order to analyze if the results are dependent on the neighborhood. The model was implemented in NetLogo.

Position Papers - Chair: Prof. Dr. Gracaliz Dimuro

1. Conduct, Cooperation and Alliances: an Analysis of Interaction Among Firms Using an ABS Model

Rogerio Morano, Edmilson Moraes, Centro Universitário da FEI, Brazil.

Abstract. Through agent-based simulation was modeled a market where alliances between companies to complement the competences and abilities are fundamental to exploiting new opportunities. The strategic enterprise behavior based on management, in order to attend the goals of stakeholders or shareholders must affect the alliances and their intensity and fragility levels. Enterprises facing market opportunities which request strategic alliances can or cannot cooperate on the others according to their strategic behavior profiles and according to the historical cooperation evaluation of their potential partners. The model of agent-based simulation proposed for such essay, uses roles based on Sugarscape, idealized for Epstein and Axtell (1996), on prisoner dilemma for n-players and concepts existents about cooperation, stakeholders and shareholders theories and enterprise alliances. It has been verified that the emergence of cooperation can occur, but depends on how fierce is the competition in terms of existing firms in the market initially and the diversity of firms in terms of their internal cost structures.

2. A Model for Agent Communication Based on Imprecise Information Using Synonyms

Fabio Aiub Sperotto; Diana Adamatti, Universidade Federal do Rio Grande - FURG, Brazil.

Abstract. This paper describes the development of an application to communication between agents. The study involves the concepts of agents and communication issues in their interactions. Using the ontology as a technique of classification of knowledge, the application includes an approach to build an intermediate component between agents and ontological knowledge base, using fuzzy application in treatment of inaccuracy information based in synonymous. Protégé editor is chosen to develop the ontology in OWL. The component uses Jena and SPARQL for manipulation of the ontology. The case study is used to model multi-agent system that represents the urban vegetable garden of Parque São Jerônimo (Spain).

3. Competitiveness and Social Inclusion within National Programme for Production and Use of Biofuels: negative feedbacks on profitability awareness in sharp Institutional Settlements in Brazil South Region concerning soybean oil.

André Zopelari, National Institute for Spatial Research, Brazil; Aldara César, Universidade Federal
Fluminense, Brazil.

Abstract. This paper intends to make some inferences about the relation of competiveness and social inclusion, and interpret in an operational manner the success of South Region soybean familiar growers ascribed to the National Programme for Biofuels Production and Use. It inquires the hypothesis of sharp institutional arrangements acting as an interface in the social system through whose structure the interrelation between competitiveness and social inclusion might take place. The methodology include collected data, statistical treatment of series and modelling the system. The theoretical framework ranged from Ulrich Becks Risk Society, Garret Hardins Tragedy of the Commons and Elinor Ostroms Governing the Commons to Cesars three-dimension analyses of governance towards competitiveness. The assessments confirmed that Insitutional Settlements are suitable to preclude Risks, but it needs finer operationalization. The model helped to light that the most sensitive variable is profitability and if there are severe perturbations, then the negative feedbacks will trigger social vulnerability.

4. Modeling Role Interactions in a Social Organization for the Simulation of the Social Production and Management of Urban Ecosystems: the case of San Jeronimo Vegetable Garden of Seville, Spain

Flávia Pereira dos Santos, Universidade Federal de Rio Grande, Brazil; Thiago Rodrigues, FURG, Brazil;
Glenda Dimuro, Universidad de Sevilla, España; Diana Adamatti, Universidade Federal do Rio Grande,FURG,
Brazil; Gracaliz Dimuro, Universidade Federal do Rio Grande, Brazil; Antonio Carlos da Rocha Costa, FURG,
Brazil; Esteban de Manuel Jerez, Universidad de Sevilla, España

Abstract. This paper presents some preliminary results obtained in the modeling of a multiagent system for the simulation of the social production and management of a urban ecosystem, in particular, the project of the San Jerónimo Vegetable Garden of city of Seville, Spain. We introduce a study regarding the interactions between agent roles in this particular social organization. For that, we use Activity Diagrams of UML , which provide a clear visualization of the communication between agent roles and allow the identification of communication protocols used by the agents. Furthermore, we show an initial proposal for the encapsulation of those protocols in CArtAgO artifacts, presenting a more modular approach for agent communication in multiagent systems.

9:30 – 10:00 
BWSS 2012 - long presentations

1. A new model of agent self-regulation based on profile discovery in social networks applied to the ultimatum game

Murian Ribeiro, Universidade Federal de Pelotas, Brazil; Marilton de Aguiar, UFPel, Brazil.

Abstract. This paper proposes a new model of interactions between agents who play the Ultimatum Game (UG) from the characteristics of knowledge discovery techniques and interactions in Social Networking Sites (SNS), more precisely on Twitter. To support the work, the authors present simulations using the UG with a spatial and evolutionary approach as well as technical knowledge discovery using SNS. With this we intend to find a more efficient way of interactions in UG, where failure is reduced in each round. For this purpose, the authors present here two new techniques that will be internalized in agents: the use of a historic reputation of the interactions between agents and, in certain periods of time, to perform the profile discovery profile of the agent offer in a general scope and their particular interactions with each agent.

10:00 - 10:30

BWSS 2012 - Panel

10:30 - 12:30

Social Simulation: Seeing ahead – scanning the future, looking to the tendencies of Computation and Complexity Sciencies, namely Agents and Artificial Intelligence

Participants: Prof. Dr. Alan Kirman, Dr. Armando Geller, Prof. Dr. Bruno Reis, Prof. Dr. Jaime Sichman

12:30 - 14:00

Technical Session 5 - Chair: Prof. Dr. Jaime Sichman

1. Stock prices assessment: proposal of a new index based on volume weighted historical prices through the use of computer modeling

Tiago Colliri, Fernando Ferreira, University of Sao Paulo, Brazil.

Abstract. The importance of considering the volumes to analyze stock prices movements can be considered as a well-accepted practice in the financial area. However, when we look at the scientific production in this field, we still cannot find a unified model that includes volume and price variations for stock assessment purposes. In this paper we present a computer model that could fulfill this gap, proposing a new index to evaluate stock prices based on their historical prices and volumes traded. Besides the model can be considered mathematically very simple, it was able to improve significantly the performance of agents operating with real financial data. Based on the results obtained, and also on the very intuitive logic of our model, we believe that the index proposed here can be very useful to help investors on the activity of determining ideal price ranges for buying and selling stocks in the financial market.

2. An ABM to monitor landscape dynamics and to undertake collective foresight investigations in the Amazon

Pierre Bommel, CIRAD & PUC-Rio, France;Poccard-Chapuis René, CIRAD & EMBRAPA, France; Bendahan
Amaury, EMBRAPA, Brazil; Coudel Emilie, CIRAD & EMBRAPA, France.

Abstract. By seeking for alternative land uses in the Amazon, we designed an Agent-Based Model (ABM) containing a set of rural practices for small-scale farmers. In order to reach a more sustainable development, we analyze the benefits and the constraints of these practices. By comparing various production activities starting from the same initial conditions, we test several strategies and their efficiency faced to different initial conditions and environmental laws. Our study does not compare solely the financial profits of the agricultural activities. But it seeks to better understand and assess the feasibility of new activities in terms of family labor management, availability of land and economic profitability. Our first results conclude that a strict compliance with the law is not economically sustainable if the farmers still apply their standard land use strategies. We hope that this model could become a useful tool for the small farmers. By easily modifying the behavior of an agent, they could virtually invent and assess the efficiency of new practices on their farm. We also hope that this tool could become a means to facilitate dialogue between different stakeholders in the Amazon, in order to achieve more sustainable development.

3. A multiagent based road pricing approach for urban traffic management

Anderson Tavares, Universidade Federal do Rio Grande do Sul, Brazil; Ana Bazzan, UFRGS, Brazil.

Abstract. Traffic is a social system composed by different interacting entities, and its optimization is not a trivial task. When drivers and infrastructure co-adapt to deal with the varying demand and infrastructure changes, respectively, centralized traffic optimization approaches face many difficulties. This work presents a multiagent based approach that uses variable road pricing to improve traffic efficiency. While infrastructure updates roads prices to cope with the varying demand, drivers try to adapt themselves to the road network changes in order to minimize their costs. Drivers have different preferences, caring either about their travel time (being hasty) or credit expenditure (being economic). Results shows that the proposed road pricing approach benefits the hasty drivers, while more sophisticated pricing update policies need to be developed in order to create better alternatives for economic drivers.

4. An Agent-Based Model for the Discussion of Institutions, Welfare and Capitalism

Luciano Mattar, Bruno Reis, Universidade Federal de Minas Gerais, Brazil.

Abstract. From an agent-based model inspired by Tiebouts model, in which assumptions about decentralized search of autonomous individuals that aim higher utility trough choices between jurisdictions with different political decision institutions are operationalized, we will make the discussion about the validity of such assumptions for the case of empirical situations under background of capitalist mode of production and social organization.

16:00 - 16:30

Technical Session 6 - Chair: Diana Adamatti

1. Reduction of Coalition Structure's Search Space based on Domain Information: an Application in Smart Grids

Gabriel Ramos, Universidade Federal do Rio Grande do Sul, Brazil;Ana Bazzan, UFRGS, Brazil.

Abstract. Smart grids have received great attention in recent years. Among many technologies that smart grids are made of, the concept of vehicle-to-grid (V2G) arises, which allows the use of electric vehicles'' batteries to provide energy back to the grid when needed. An interesting research approach is the formation of coalitions among electric vehicles to provide electric power back to the grid, increasing its reliability and stability. In this paper, we propose a technique that uses smart grids'' domain information to establish constraints on coalition formation process, promoting the pruning of the coalition structure''s search space. We evaluate our approach by showing that it can drastically prune the search space, which makes possible forming coalitions for a relatively higher number of agents.

2. An Evolutionary Learning Approach for Robot Path Planning with Fuzzy Obstacle Detection and Avoidance in a Multi-agent Environment

Tauã Cabreira, Universidade Federal do Rio Grande, Brazil; Marilton Aguiar, UFPEL, Brazil; Gracaliz
Dimuro, Universidade Federal do Rio Grande, Brazil.

Abstract. This paper describes a Fuzzy-Genetic Algorithm Approach for path planning of mobile robots with obstacle detection and avoidance in static and dynamic scenarios. Through the software Netlogo, used in simulations of multi-agent applications, a seminal model was developed for the given problem. The model, which contains a robot and scenarios with or without obstacles, is responsible for determining the best path used by a robot to achieve the goal state in a shorter number of steps and avoiding collisions. Additionally, a performance evaluation of this model in comparison with A* algorithm is presented.

Chairs: Graçaliz Dimuro, Antônio Carlos da Rocha Costa, Jaime Sichman, Helder Coelho, Diana Adamatti

Invited Talk 2: Prof. Dr. Alan Kirman, chair: Prof. Dr. Jaime Sichman