Ana Paula Rocha
Universidade do Porto, Faculdade de Engenharia, Faculty Member
Our intent is to present a mechanism suitable for agents that, immersed in an environment that is simultaneously cooperative and competitive, have to learn its own best behaviour not only from an individual point of view but also from a... more
Our intent is to present a mechanism suitable for agents that, immersed in an environment that is simultaneously cooperative and competitive, have to learn its own best behaviour not only from an individual point of view but also from a global perspective of the system. We consider the learning mechanism we propose to be a multi-agent learning mechanism not only because there are multiple agents learning concurrently in the same environment but also because it allows them to understand how to improve their performance and still not to damage the performance of the other agents. We tested our learning mechanism over the Disruption Management in Airline Operations Control Center application domain and the results show that it provides a good performance to the agents in cooperative as well as in competitive situations in the environment.
Electronic commerce competitiveness, due to market openness and dynamics, enabled thearising of new organisational structures, as it is the case with Virtual Enterprises. The VirtualEnterprise (VE) concept can effectively answer to new... more
Electronic commerce competitiveness, due to market openness and dynamics, enabled thearising of new organisational structures, as it is the case with Virtual Enterprises. The VirtualEnterprise (VE) concept can effectively answer to new demanding market requirements, as itcombines the core competencies of independent and heterogeneous enterprises thatcollaborate in a temporary and loosely linked network, thereby presenting high flexibility andagility. However, institutional and social laws must be introduced here to ...
Research Interests:
ABSTRACT Previous work on computational trust has delivered robust aggregation engines that proved competent in estimating the trustworthiness of agents. However, most of these approaches were evaluated through simulation using simple and... more
ABSTRACT Previous work on computational trust has delivered robust aggregation engines that proved competent in estimating the trustworthiness of agents. However, most of these approaches were evaluated through simulation using simple and static agents' populations that did not consider the social account of trust. In this paper, we show by experimental analysis that these approaches tend to perform poorly when the populations of agents form social structures that evolve with the situation and the relationship existing between partners. Moreover, we present an approach to social-aware computational trust based on Social Tuner, a new component that we developed that infers the benevolence of the trustee toward the truster from the available evidence. We show by experimental analysis that this approach outperforms the social-less aggregation engines in a relevant way. The experiments are run using a model of agents' behavior grounded on the literature of social trust and benevolence that we have developed and describe in detail in this paper.
Research Interests:
Research Interests:
Research Interests:
Research on negotiation and task allocation has been in the multi-agent systems realm since its inception as a research field. More recently, social aspects of agent-hood have received increasing attention, namely developing on the fields... more
Research on negotiation and task allocation has been in the multi-agent systems realm since its inception as a research field. More recently, social aspects of agent-hood have received increasing attention, namely developing on the fields of normative and trust systems. The integration of these different research contributions will allow to build robust applications for electronic agreement negotiation, aiming at their acceptability and application in industry.
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ABSTRACT Argumentation and trust models have been increasingly used in multi-agent systems research, with applications in several domains such as e-commerce. Negotiation is a form of interaction in which argumentation and trust can play a... more
ABSTRACT Argumentation and trust models have been increasingly used in multi-agent systems research, with applications in several domains such as e-commerce. Negotiation is a form of interaction in which argumentation and trust can play a relevant role. Argumentation in a negotiation context has been defined as a way of interaction between trading parties that enables them to exchange information in order to explain their current position with the intention of increasing the chance of success. We propose an argumentation model based on past contractual data aiming at enriching electronic contracting processes. The idea behind this argumentation model is to prevent failures in future agreements. For that, an important step is to define a reasoning model that allows trading parties to point out some past contractual failures or explain such past failures. The purpose of this paper is then to investigate on how argumentation-based negotiation using historical contractual data may affect the outcome of a contracting process, taken as a comprehensive activity ranging from negotiation, monitoring and enactment assessment. This may be achieved through a careful selection of the partner with whom a contract is to be established, complemented with an argumentation-based negotiation of contract terms.
Research Interests:
Research Interests:
The community of multi-agent systems has been studying ways to improve the selection of partner agents for joint action. One of such approaches consists in estimating the trustworthiness of potential partners in order to decrease the risk... more
The community of multi-agent systems has been studying ways to improve the selection of partner agents for joint action. One of such approaches consists in estimating the trustworthiness of potential partners in order to decrease the risk inherent to interacting with unknown agents. In this paper, we study the effect of using trust in the process of selecting partners in electronic business.
Research Interests:
Electronic Institutions are comprehensive frameworks that may effectively help in the collaborative work of virtual organization activities. This paper focuses on an effort to create e-contracting and ontology-based services in the... more
Electronic Institutions are comprehensive frameworks that may effectively help in the collaborative work of virtual organization activities. This paper focuses on an effort to create e-contracting and ontology-based services in the context of Electronic Institutions. The e-contracting services provide automatic specification of business agreements by formalizing them through e-contracts, plus the procedures for enforcing them.
Commerce is the way customers and suppliers meet at a certain place and a certain time in order to announce buying and selling intentions that eventually match and successfully start business transactions. Due to innovations in... more
Commerce is the way customers and suppliers meet at a certain place and a certain time in order to announce buying and selling intentions that eventually match and successfully start business transactions. Due to innovations in information and communication technologies of the past years, time and space restrictions have been weakened and, therefore, those business transactions became easier.
Electronic Commerce technology has changed the way traditional business is being done. Transactions' complexity is increased due both to the huge amount of available information and also to the environment dynamics. Moreover, Electronic... more
Electronic Commerce technology has changed the way traditional business is being done. Transactions' complexity is increased due both to the huge amount of available information and also to the environment dynamics. Moreover, Electronic Commerce has enabled the arising of new economical structures, as it is the case of Virtual Organisations. Our research aims at providing flexible and general-purpose systems for intelligent negotiation, both for Electronic Commerce and Virtual Organisation formation.
Economic organisations are facing new challenges due to the proliferation of Electronic Markets where competition and responsiveness are issues that will determine organisation's economic survival. A Virtual Enterprise is a temporary... more
Economic organisations are facing new challenges due to the proliferation of Electronic Markets where competition and responsiveness are issues that will determine organisation's economic survival. A Virtual Enterprise is a temporary network of individual enterprises, which, due to its higher flexibility and agility is capable of effectively responding to those challenging requirements. This paper proposes an Electronic Market system's architecture together with a multi-criteria negotiation protocol for Virtual Enterprise formation.
ABSTRACT This paper describes a framework for cooperation suitable for being exploited in a society of cooperative distributed agents. We briefly present a tool UPShell-University of Porto Shell, which may be used to generate specific... more
ABSTRACT This paper describes a framework for cooperation suitable for being exploited in a society of cooperative distributed agents. We briefly present a tool UPShell-University of Porto Shell, which may be used to generate specific Intelligent Systems, although its main purpose is to build up a community of coarse-grain, semi-autonomous agents out either of those generated Intelligent Systems or of already pre-existent Knowledge Based Systems.
Abstract. Trust estimation of partner agents is considered a fundamental step in the process of selecting partners. In previous work, we proposed SinAlpha, an agent-based aggregation engine that computes the trustworthiness of candidate... more
Abstract. Trust estimation of partner agents is considered a fundamental step in the process of selecting partners. In previous work, we proposed SinAlpha, an agent-based aggregation engine that computes the trustworthiness of candidate partners by aggregating their historical contractual evidences, taking into account important properties of the dynamics of trust.
Computational Trust and Reputation (CTR) systems are essential in electronic commerce to encourage interactions and suppress deceptive behaviours. This paper focus on comparing two different kinds of approaches to evaluate the... more
Computational Trust and Reputation (CTR) systems are essential in electronic commerce to encourage interactions and suppress deceptive behaviours. This paper focus on comparing two different kinds of approaches to evaluate the trustworthiness of suppliers. One is based on calculating the weighted mean of past results. The second one applies basic properties of the dynamics of trust. Different scenarios are investigated, including a more problematic one that results from introducing newcomers during the simulation.
Abstract Computational trust systems are getting popular in several domains such as social networks, grid computing and business-to-business systems. However, the estimation of the trustworthiness of agents is not trivial in scenarios... more
Abstract Computational trust systems are getting popular in several domains such as social networks, grid computing and business-to-business systems. However, the estimation of the trustworthiness of agents is not trivial in scenarios where the existing trust evidences are scarce. We propose an online, situation-aware trust model that uses the information gain metric to dynamically extract tendencies of failure of target agents, improving the process of selection of partners in a relevant way.
Ontologies are crucial in B2B electronic commerce in general and in the Virtual Enterprise scenario in particular, enabling the mutual understanding between multiple business participants. This paper considers the development of a... more
Ontologies are crucial in B2B electronic commerce in general and in the Virtual Enterprise scenario in particular, enabling the mutual understanding between multiple business participants. This paper considers the development of a specific ontology in the home automation business area, illustrated in the Virtual Enterprise formation process. The ontology developed for the home automation (domotics) domain enumerates different products, its attributes, mutual relations and implicit business rules.
The community of multi-agent systems has been studying ways to improve the selection of partner agents for joint action. One of such approaches consists in estimating the trustworthiness of potential partners in order to decrease the risk... more
The community of multi-agent systems has been studying ways to improve the selection of partner agents for joint action. One of such approaches consists in estimating the trustworthiness of potential partners in order to decrease the risk inherent to interacting with unknown agents. In this paper, we study the effect of using trust in the process of selecting partners in electronic business.
Computational trust systems are currently considered enabler tools for the automation and the general acceptance of global electronic business-tobusiness processes, such as the sourcing and the selection of business partners outside the... more
Computational trust systems are currently considered enabler tools for the automation and the general acceptance of global electronic business-tobusiness processes, such as the sourcing and the selection of business partners outside the sphere of relationships of the selector. However, most of the existing trust models use simple statistical techniques to aggregate trust evidences into trustworthiness scores, and do not take context into consideration.
Electronic transactions are of increasing use due to its openness and continuous availability. The rapid growth of information and communication technologies has helped the expansion of these electronic transactions, however, issues... more
Electronic transactions are of increasing use due to its openness and continuous availability. The rapid growth of information and communication technologies has helped the expansion of these electronic transactions, however, issues related to security and trust are yet limiting its action space, mainly in what concerns business to business activity.
The development of computational trust models is growing in attention in the community of multi-agent systems and these models are currently seen as of extreme importance in social networks, electronic business and grid computing, among... more
The development of computational trust models is growing in attention in the community of multi-agent systems and these models are currently seen as of extreme importance in social networks, electronic business and grid computing, among others. However, one of the biggest limitations in validating the existing computational trust models is the absence of realistic models of the behavior of agents. In fact, most of the work done in this area assumes that agents behave following simple and static probabilistic models.
Abstract. In current days, a great effort, on several scientific research areas, is being devoted to the automation of the procurement processes in the framework of business-to-business relations. However, several constraints limit the... more
Abstract. In current days, a great effort, on several scientific research areas, is being devoted to the automation of the procurement processes in the framework of business-to-business relations. However, several constraints limit the extension of the procurement process to truly open and global marketplaces. One such constraint is the lack of valid trust mechanisms that allow business agents to select partners outside the sphere of known relationships, in the hope of better deals.
Abstract: Trust management is nowadays considered a promising enabler technology to extend the automation of the supply chain to the search, evaluation and selection of suppliers located world-wide.
Trust estimation is an essential process in several multi-agent systems domains. Although it is generally accepted that trust is situational, the majority of the Computational Trust and Reputation (CTR) systems existing today are not... more
Trust estimation is an essential process in several multi-agent systems domains. Although it is generally accepted that trust is situational, the majority of the Computational Trust and Reputation (CTR) systems existing today are not situation-aware. In this paper, we address the inclusion of the context in the trust management process. We first refer the benefits of considering context and make an overview of recently proposed situational-aware trust models.
Abstract: In an efficient Virtual Enterprise (VE), where all the partners, both sending and receiving messages have to lead to acceptable and meaningful agreements, it is necessary to have common standards (an interaction protocol to... more
Abstract: In an efficient Virtual Enterprise (VE), where all the partners, both sending and receiving messages have to lead to acceptable and meaningful agreements, it is necessary to have common standards (an interaction protocol to achieve deals, a language for describing the messages' content and ontology for describing the domain's knowledge). This paper introduces first the ForEV platform, implemented through a Multi-Agent System.
In this era of digital economy, commercial relationships between business partners are increasing in flexibility, with new business binds being created whenever a business opportunity arises. Moreover, the instability in demand increases... more
In this era of digital economy, commercial relationships between business partners are increasing in flexibility, with new business binds being created whenever a business opportunity arises. Moreover, the instability in demand increases the need for enterprises to procure new partners as well as the associated risk of dealing with partners that may be unknown beforehand.
Trust estimation is a fundamental process in several multi-agent systems domains, from social networks to electronic business scenarios. However, the majority of current computational trust systems is still too simplistic and is not... more
Trust estimation is a fundamental process in several multi-agent systems domains, from social networks to electronic business scenarios. However, the majority of current computational trust systems is still too simplistic and is not situation-aware, jeopardizing the accuracy of the predicted trustworthiness values of agents. In this paper, we address the inclusion of context in the trust management process.
Abstract. The Airline Operations Control Centre (AOCC) organization is responsible for monitoring and solving operational problems in day-to-day airline operations. It includes human expert teams specialized in solving problems related... more
Abstract. The Airline Operations Control Centre (AOCC) organization is responsible for monitoring and solving operational problems in day-to-day airline operations. It includes human expert teams specialized in solving problems related with aircrafts, crew members, and passengers, in a process called disruption management or operations recovery.
Most of the research efforts dealing with airline scheduling have been done on off-line plan optimization. However, nowadays, with the increasingly complex and huge traffic at airports, the real challenge is how to react to unexpected... more
Most of the research efforts dealing with airline scheduling have been done on off-line plan optimization. However, nowadays, with the increasingly complex and huge traffic at airports, the real challenge is how to react to unexpected events that may cause plan-disruptions, leading to flight delays.
Moreover these disruptive events usually affect at least three different dimensions of the situation: the aircraft assigned to the flight, the crew assignment and, often forgotten, the passengers’ journey and satisfaction.
This book includes answers to this challenge and proposes the use of the Multi-agent System paradigm to rapidly compose a multi-faceted solution to the disruptive event taking into consideration possible preferences of those three key aspects of the problem.
Negotiation protocols taking place between agents that are experts in solving the different problem dimensions, combination of different utility functions and, not less important, the inclusion of the human in the automatic decision-making loop make MASDIMA, the system described in this book, well suited for real-life plan-disruption management applications
Moreover these disruptive events usually affect at least three different dimensions of the situation: the aircraft assigned to the flight, the crew assignment and, often forgotten, the passengers’ journey and satisfaction.
This book includes answers to this challenge and proposes the use of the Multi-agent System paradigm to rapidly compose a multi-faceted solution to the disruptive event taking into consideration possible preferences of those three key aspects of the problem.
Negotiation protocols taking place between agents that are experts in solving the different problem dimensions, combination of different utility functions and, not less important, the inclusion of the human in the automatic decision-making loop make MASDIMA, the system described in this book, well suited for real-life plan-disruption management applications
Research Interests:
Trust estimation of partner agents is considered a fundamental step in the process of selecting partners. In previous work, we proposed SinAlpha, anagent-based aggregation engine that computes the trustworthiness of candidate partners by... more
Trust estimation of partner agents is considered a fundamental step in the process of selecting partners. In previous work, we proposed SinAlpha, anagent-based aggregation engine that computes the trustworthiness of candidate partners by aggregating their historical contractual evidences, taking into account important properties of the dynamics of trust. In this paper, we further argue on the benefits of the trust dynamics, and we describe the ContextualFitness component, a new element of our computational trust system that brings contextual information into the trust loop, by relating the estimated trustworthiness of partners to the specific current business situation. Experimental results show that such an approach significantly improves partners selection, due to its ability in detecting the flaws of the target population, even when the available historical evidences are scarce.