Prova de Doutoramento

28 Agosto 2017, 15:20 - Maria de Fátima Ferreira Sampaio

Candidate: Joana Carvalho Filipe de Campos Nº 55848/D

Title: Modelling Interpersonal Conflict in Multi-Agent Societies

Date: 4/09/2017

Time: 11:00

Location: Anfiteatro PA3 (Piso -1, Pavilhão de Matemática) IST, Alameda

Advisor: Professora Ana Maria Severino de Almeida e Paiva

Abstract: Conflict and conflict dynamics are phenomena intertwined with social change. The absence of conflict only brings stagnation opposed to progress and improvement. Therefore, being able to cope with conflicts and detect them beforehand are social skills very important in life. Throughout our lives, better or worse, we learn how to cope with conflict by experience. Yet, questions such as “how do we know we are in a conflict?” or “what makes some conflicts emerge while others subside?” are difficult to answer unequivocally. In Artificial Intelligence, conflicts also abound in multi-agent systems. Depending on the needs of the systems, different mechanisms (e.g. joint intentions or enforcement of norms) have been applied to cope with what researchers often call “failures”. Yet, as systems become more complex, we can no longer assume that agents will strive for the overall well-being of the system. Thus, a less simplistic view of conflict is necessary, so that agents are able to detect and anticipate conflicts.
In this thesis, we aim to address the problem of representing the interpersonal conflict construct in a cognitive agent architecture. To that end, we propose a model that is based on sound theoretical concepts and it allows to make conflict explicit. However, to create a model that is more flexible and expressive, we believe that theory and real deep data must be combined. More often than not, the models described in the literature are focused on the effects and use high level features as predictors of conflict handling modes. Little emphasis has been given to actual process and to how it unfolds, information that is critical to create agents that detect and react to conflicts in an appropriate way.       
In this thesis to capture the subtleties of conflict and its dynamics, we collected data from real usersby the means of cultural probes and the analysis of interactions of children playing a negotiation game. In the latter, we created a dataset that encompasses eleven dyadic interactions of 10- to 12-year-old children playing a mixed-motive – the Game-Of-Nines. Our aim was to trace the conflict process in conflict-prone situations and therefore we sought to observe and trace cognitive processes by analyzing social signals over time. Those signals include gaze, electrodermal activity and the exchange of offers in this negotiation game. Such analysis allowed us to detail our initial model of conflict, which was based only on theoretical concepts, by introducing mechanisms that create a dynamic system that depends on the changing dynamics of the interaction and whether the agent frames the situation as a conflict or not.    

Prova de CAT

23 Agosto 2017, 09:44 - Maria de Fátima Ferreira Sampaio

Candidate: Baojiang Yang n.º 82677/D

Title: Essays in Telecommunications Management and Policy

Date: 25/08/2017

Time: 16h

Location: Sala 0.19, Informatica II pavilion, Instituto Superior Técnico, Universidade de Lisboa 

Advisor: Professor Pedro M. Ferreira and Professor Mário J. Gaspar da Silva 

Co-advisors: Professor Miguel Godinho de Matos

Abstract: As digitization increasingly reshapes the landscape of home-based telecommunication industries, telecommunication companies react to the challenges with various strategic managerial policies. Consumers in the meantime, are directly influenced by such policies. The welfare impacts are usually complicated and non-transparent to both consumers and policy makers. My thesis aims at leveraging large-scale fine-grained empirical data to investigate the impacts of several prevalent firm initiated strategies on both sides of the market, i.e. consumers and firms. The thesis comprises of three studies. The first study focuses on measuring the impact of service contract policies that are prevalent in home-based telecommunication services in many developed countries. We study the impact of shortening the lock-in periods associated with triple play service contracts on both firms and consumers using household level data from a large telecommunications provider. We show that shortening the lock-in period decreases the profit of the firm more than it increases consumer surplus and, therefore, regulators need to be very careful when considering regulating these periods. If regulators shorten lock-in periods then firms are likely to respond by increasing prices to maintain their return on investment. The analyses show that this behavior, however, will make consumers worse off compared to the world in which lock-in periods do not change. This result shows that regulators shortening lock-in periods may also need to regulate prices to avoid a significant loss to consumers. The second and third study investigates how consumers combine different sources of social information when making online search and purchase decisions. In the second study, we use individual level clickstream data from a Video-on-Demand service to study how consumers combine two channels of social information, from friends vs from the crowd, differently when they are just browsing and when they are effectively considering purchasing a product. We find that in our case, consumers seem to start by browsing products they heard about from friends and popularity signals seem to only play a role closer to purchase. This result shows that a good way to help consumers navigate large catalogs of products might be to first show them products that consumers similar to them bought and then later highlight the popularity information. As part of future work, I propose in the third study an incentive-aligned randomized online lab experiment to extensively study the mechanism of social influence during consumer shopping process. We aim to leverage the randomized experiment to disentangle the social influence from a series of potentially confounded unobservables. Supplementary survey responses will be analyzed in order to better understand the role social signals play during different stages. With a more thorough understanding of the mechanism of social influence through both the observational study and randomized experiment, we aim to study the potential impact of firm's strategical manipulation in the display of social signals on both sides of the market. 

Prova de CAT

25 Julho 2017, 10:46 - Maria de Fátima Ferreira Sampaio

Candidate: Fernando Pedro Pascoal dos Santos n.º 64757/D

Title: Collective dynamics of cooperation

Date: 25/07/2017

Time: 11h

Location: Sala 1.38, Taguspark, Instituto Superior Técnico, Universidade de Lisboa

Advisor: Professor Francisco João Duarte Cordeiro Correia dos Santos

Co-advisors: Professora Ana Maria Severino de Almeida e Paiva and Professor Jorge Manuel dos Santos Pacheco

Abstract: Explaining cooperation is one of the biggest challenges of the XXIst century. Understanding its evolutionary dynamics is fundamental to comprehend the origin of societies, institutions and the own human nature. Simultaneously, cooperation models may explain the sparing engagement in tackling contemporary problems – such as climate change, international conflict, corruption or economic poverty and inequality – providing a toolkit to experiment effective policies and novel interaction paradigms. In this thesis, we employ computational and mathematical methods (inspired in evolutionary game theory and artificial intelligence learning algorithms) to explore collective dynamics in three very specific domains that, hopefully, allow us to contribute to the wide challenge of understanding cooperation. First, we explore which social norms – here the rules that classify behaviours as good or bad – are able to promote cooperation. The formal link between social norms and cooperation is established with models of indirect reciprocity (IR). IR models comprise individuals who adopt heuristics for deciding to cooperate or defect based on reputations that spread in a population after each interaction. Second, we will explore cooperation in the context of multiplayer ultimatum games where, besides dealing with a continuous strategy space, we consider group interactions in which individuals can jointly sacrifice their earnings to immediately punish selfish opponents. Third, we will explore the scenario of asymmetric games of cooperation. These are useful to model the multi-sectorial interactions that occur in our society, for instance, when public, private and civil agents take part in socio-political dilemmas.

Prova de Dissertação do MEIC-A

24 Julho 2017, 15:36 - Maria da Glória Pires Garcia Dias

Candidato: Nuno Ricardo Gomes Pires (75910)

Título da Dissertação: Análise e Visualização de Incidências de Doenças Transmissíveis

Data: 26 de julho de 2017

Hora: 14:30h

Local: Sala de Reuniões Porta 0.20, Pavilhão de Informática II - IST - Alameda

Orientação: Prof. Vasco Miguel Gomes Nunes Manquinho

Candidato: João Pedro Mateus Alexandre (73754)

Título da Dissertação: Automatic generation of test cases for Massive Open Online Courses (MOOCs)

Data: 28 de julho de 2017

Hora: 10:00h

Local: Sala de Reuniões Porta 0.20, Pavilhão de Informática II - IST - Alameda

Orientação: Prof. Vasco Miguel Gomes Nunes Manquinho

Prova de Dissertação do MEIC-T

19 Julho 2017, 11:33 - Maria da Glória Pires Garcia Dias

Candidato: André Filipe Cruz Fonseca (84977)

Título da Dissertação: Enclothed Cognition in Virtual Worlds

Data: 26 de julho de 2017

Hora: 9:00h

Sala de Reuniões Porta 0.20, Pavilhão de Informática II - IST - Alameda

Orientação: Prof. Carlos António Roque Martinho

Candidato: Samuel Simão Canada Gomes (76415)

Título da Dissertação: Application and Design of GPU Parallel RRT for Racing Car Simulation

Data: 26 de julho de 2017

Hora: 10:30h

Local: Sala de Reuniões Porta 0.20, Pavilhão de Informática II - IST - Alameda

Orientação: Prof.João Miguel de Sousa de Assis Dias / Prof. Carlos António Roque Martinho