Increasing the expressiveness for virtual agents. Autonomous generation of speech and gesture for spatial description tasks

Bergmann K, Kopp S. Increasing the expressiveness for virtual agents. Autonomous generation of speech and gesture for spatial description tasks. In: Decker KS, Sichman JS, Sierra C, Castelfranchi C, eds. Proceedings of the 8th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2009). Ann Arbor, MI: IFAAMAS; 2009: 361-368.Embodied conversational agents are required to be able to express themselves convincingly and autonomously. Based on an empirial study on spatial descriptions of landmarks in direction-giving, we present a model that allows virtual agents to automatically generate, i.e., select the content and derive the form of coordinated language and iconic gestures. Our model simulates the interplay between these two modes of expressiveness on two levels. First, two kinds of knowledge representation (propositional and imagistic) are utilized to capture the modality-specific contents and processes of content planning. Second, specific planners are integrated to carry out the formulation of concrete verbal and gestural behavior. A probabilistic approach to gesture formulation is presented that incorporates multiple contextual factors as well as idiosyncratic patterns in the mapping of visuo-spatial referent properties onto gesture morphology. Results from a prototype implementation are described

Investigating the Emotional Response to COVID-19 News on Twitter: A Topic Modeling and Emotion Classification Approach

Media has played an important role in public information on COVID-19. But distressing news, e.g., COVID-19 death tolls, may trigger negative emotions in public, discouraging them from following the news, which, in turn, can limit the effectiveness of the media. To understand people’s emotional response to the COVID-19 news, we have investigated the prevalence of basic human emotions in around 19 million user responses to 1.7 million COVID-19 news posts on Twitter from (English-speaking) media across 12 countries from January 2020 to April 2021. We have used Latent Dirichlet Allocation (LDA) to identify news themes on Twitter. Also, the Robustly Optimized BERT Pretraining Approach (RoBERTa) model was used to identify emotions in the tweets. Our analysis of the Twitter data revealed that anger was the most prevalent emotion in user responses to the news coverage of COVID-19. That was followed by sadness, optimism, and joy, steadily over the period of the study. The prevalence of anger (in user responses) was higher for the news about authorities and politics while optimism and joy were more prevalent for the news about vaccination and educational impacts of COVID-19 respectively. The prevalence of sadness in user responses, however, was the highest for the news about COVID-19 cases and deaths and the impacts on the families, mental health, jails, and nursing homes. We also observed a higher level of anger in the user responses to the (COVID-19) news posted by the USA media accounts (e.g., CNN Politics, Fox News, MSNBC). Optimism, on the other hand, was found to be the highest for Filipino media accounts

Du raisonnement social chez les agents : une approche fondée sur la théorie de la dépendance

This thesis presents the model of a social reasoning mechanism based on dependence theory. This model enables an agent to reason about the others, in particular to calculate his dependence relations and dependence situations. An agent is said to be dependent on another if the latter can help/prevent him to achieve one of his goals. We consider our social reasoning mechanism as an essential building block for the design of really autonomous artificial agents, which are immersed in an open multi-agent world. By open, we mean that agents may enter or leave the agency at any moment. In such systems, as the organisation of the agents can not be conceived at design time, the cooperative problem solving paradigm is based on dynamic coalition formation. In this context, agents must be able to adapt themselves to dynamically changing conditions, by evaluating at execution time if their goals are achievable and if their plans are feasible. As we do not suppose that agents are benevolent, our model proposes a criterion to evaluate which partners are more susceptible to accept a proposition of coalition. Finally, as in these kind of systems agents usually do not have a complete and correct representation of each other, our model helps them to detect an agency level inconsistency and to choose a context to be maintained. We have implemented our social reasoning mechanism using an object-oriented approach, and we have used it to develop two applications, the DEPNET simulator and the DEPINT system, which illustrate respectively its usage in two different scientific perspectives. On one hand, concerning social simulation, our model provides a computational tool for the analysis and prediction of the occurrence of several interesting patterns of social interactions, and for the evaluation of the agents' social power. On the other hand, with respect to problem solving, our model can be used to design dynamic agents' organizations in a context of open multi-agent systems.Cette thèse présente le modèle d'un mécanisme de raisonnement social fondé sur la théorie de la dépendance. Ce modèle permet à un agent de raisonner sur autrui et plus particulièrement de calculer ses relations et situations de dépendance. Un agent est dépendant d'un autre si celui-ci peut l'aider/l'empêcher d'atteindre un de ses buts. Nous considérons notre mécanisme de raisonnement social comme un composant essentiel pour la conception d'agents artificiels réellement autonomes, évoluant dans un univers multi-agents ouvert. La notion d'ouverture désigne la capacité d'ajouter ou de retirer dynamiquement dans le système des agents. Comme dans ces systèmes l'organisation des agents ne peut pas être spécifiée pendant la phase de conception, la résolution coopérative de problèmes est fondée sur la formation dynamique de coalitions. Dans ce contexte, des agents doivent être capables de s'adapter aux changements dynamiques du système, en particulier en évaluant pendant la phase de résolution si leurs buts sont réalisables et si leurs plans sont exécutables. Comme nous ne supposons pas que les agents soient bienveillants, notre modèle fournit un critère pour évaluer les partenaires le plus susceptibles d'accepter une proposition de coalition. Enfin, comme dans ces systèmes des agents n'ont pas généralement une représentation complète et correcte les uns des autres, notre modèle leur permet de détecter une inconsistance au niveau de la société et de choisir un contexte à être maintenue. Nous avons implémenté ce mécanisme de raisonnement social en utilisant une programmation orientée objet. Nous l'avons utilisé pour développer deux applications, le simulateur DEPNET et le système DEPINT, qui illustrent son utilisation selon deux perspectives scientifiques différentes. D'une part, selon une perspective de simulation sociale, notre modèle fournit un outil informatique permettant l'analyse et la prédiction des divers schémas intéressants d'interaction sociale, et l'évaluation du pouvoir social des agents. D'autre part, selon une perspective de résolution de problèmes, notre modèle peut être utilisé pour concevoir dynamiquement l'organisation des agents dans un contexte de systèmes multi-agents ouverts

On Social Reasoning in Multi-Agent Systems

This work presents the core notions of a social reasoning mechanism, based on dependence theory. This model enables an agent to reason about the others, in particular to calculate his dependence relations and dependence situations. An agent is said to be dependent on another if the latter can help/prevent him to achieve one of his goals. We consider our social reasoning mechanism as an essential building block for the design of really autonomous artificial agents, which are immersed in an open multi-agent world. By open, we mean that agents may enter or leave the society at any moment. In such systems, as the organization of the agents can not be conceived at design time, the cooperative problem solving paradigm is based on dynamic coalition formation. In this context, agents must be able to adapt themselves to dynamically changing conditions, by evaluating at execution time if their goals are achievable and if their plans are feasible. As we do not suppose that agents are benevolent, our model proposes a criterion to evaluate which partners are more susceptible to accept a proposition of coalition. Finally, as in these kind of systems agents usually do not have a complete and correct representation of each other, our model helps them to detect an agency level inconsistency and to choose a context to be maintained

Organization Oriented Programming in Multi-Agent Systems

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Organizational Modeling Dimensions in Multiagent Systems

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Modeling Organization in MAS: A Comparison of Models

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Using a multi-agent organization description language to describe contract dynamics in virtual enterprises

International audienceThe flourishing development of various forms of virtual enterprises requires new information technology facilities to exploit Internet to collaboratively perform tasks that go across the boundaries of the member enterprises. Representation and management of contracts between these enterprises have raised a number of issues and has not yet been fully resolved. In this paper we are concerned with representation of contracts involving enterprises participating to dynamic supply-chains. In order to describe constraints and obligations entitled in such constructs, we propose to use the MOISE+ multi-agent organization description language. We use it within a multi-agent contract-management infrastructure in which each enterprise delegates the management of their out/in-sourcing contract to their dedicated agent that cooperate with the other agents to fulfil their commitments. We explore how this model can be used for such applications and more particularly to handle dynamic environments where virtual enterprises and thus the contracts, may change in a kind of reorganization process

Organization oriented programming from closed to open organizations

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