Comparing Agent Architectures in Social Simulation: BDI Agents versus Finite-state Machines

Each summer in Australia, bushfires burn many hectares of forest, causing deaths, injuries, and destroying property. Agent-based simulation is a powerful tool for decision-makers to explore different strategies for managing such crisis, testing them on a simulated population; but valid results require realistic underlying models. It is therefore essential to be able to compare models using different architectures to represent the human behaviour, on objective and subjective criteria. In this paper we describe two simulations of the Australian population\u27s behaviour in bushfires: one with a finite-state machine architecture; one with a BDI architecture. We then compare these two models with respect to a number of criteria

Towards VEsNA, a Framework for Managing Virtual Environments via Natural Language Agents

Automating a factory where robots are involved is neither trivial nor cheap. Engineering the factory automation process in such a way that return of interest is maximized and risk for workers and equipment is minimized, is hence of paramount importance. Simulation can be a game changer in this scenario but requires advanced programming skills that domain experts and industrial designers might not have. In this paper we present the preliminary design and implementation of a general-purpose framework for creating and exploiting Virtual Environments via Natural language Agents (VEsNA). VEsNA takes advantage of agent-based technologies and natural language processing to enhance the design of virtual environments. The natural language input provided to VEsNA is understood by a chatbot and passed to a cognitive intelligent agent that implements the logic behind displacing objects in the virtual environment. In the VEsNA vision, the intelligent agent will be able to reason on this displacement and on its compliance to legal and normative constraints. It will also be able to implement what-if analysis and case-based reasoning. Objects populating the virtual environment will include active objects and will populate a dynamic simulation whose outcomes will be interpreted by the cognitive agent; explanations and suggestions will be passed back to the user by the chatbot

A theoretical and practical approach to a persuasive agent model for change behaviour in oral care and hygiene

There is an increased use of the persuasive agent in behaviour change interventions due to the agent‘s features of sociable, reactive, autonomy, and proactive. However, many interventions have been unsuccessful, particularly in the domain of oral care. The psychological reactance has been identified as one of the major reasons for these unsuccessful behaviour change interventions. This study proposes a formal persuasive agent model that leads to psychological reactance reduction in order to achieve an improved behaviour change intervention in oral care and hygiene. Agent-based simulation methodology is adopted for the development of the proposed model. Evaluation of the model was conducted in two phases that include verification and validation. The verification process involves simulation trace and stability analysis. On the other hand, the validation was carried out using user-centred approach by developing an agent-based application based on belief-desire-intention architecture. This study contributes an agent model which is made up of interrelated cognitive and behavioural factors. Furthermore, the simulation traces provide some insights on the interactions among the identified factors in order to comprehend their roles in behaviour change intervention. The simulation result showed that as time increases, the psychological reactance decreases towards zero. Similarly, the model validation result showed that the percentage of respondents‘ who experienced psychological reactance towards behaviour change in oral care and hygiene was reduced from 100 percent to 3 percent. The contribution made in this thesis would enable agent application and behaviour change intervention designers to make scientific reasoning and predictions. Likewise, it provides a guideline for software designers on the development of agent-based applications that may not have psychological reactance

Using Norms To Control Open Multi-Agent Systems

Internet es, tal vez, el avance científico más relevante de nuestros días. Entre otras cosas, Internet ha permitido la evolución de los paradigmas de computación tradicionales hacia el paradigma de computaciónn distribuida, que se caracteriza por utilizar una red abierta de ordenadores. Los sistemas multiagente (SMA) son una tecnolog a adecuada para abordar los retos motivados por estos sistemas abiertos distribuidos. Los SMA son aplicaciones formadas por agentes heterog eneos y aut onomos que pueden haber sido dise~nados de forma independiente de acuerdo con objetivos y motivaciones diferentes. Por lo tanto, no es posible realizar ninguna hip otesis a priori sobre el comportamiento de los agentes. Por este motivo, los SMA necesitan de mecanismos de coordinaci on y cooperaci on, como las normas, para garantizar el orden social y evitar la aparici on de conictos. El t ermino norma cubre dos dimensiones diferentes: i) las normas como un instrumento que gu a a los ciudadanos a la hora de realizar acciones y actividades, por lo que las normas de nen los procedimientos y/o los protocolos que se deben seguir en una situaci on concreta, y ii) las normas como ordenes o prohibiciones respaldadas por un sistema de sanciones, por lo que las normas son medios para prevenir o castigar ciertas acciones. En el area de los SMA, las normas se vienen utilizando como una especi caci on formal de lo que est a permitido, obligado y prohibido dentro de una sociedad. De este modo, las normas permiten regular la vida de los agentes software y las interacciones entre ellos. La motivaci on principal de esta tesis es permitir a los dise~nadores de los SMA utilizar normas como un mecanismo para controlar y coordinar SMA abiertos. Nuestro objetivo es elaborar mecanismos normativos a dos niveles: a nivel de agente y a nivel de infraestructura. Por lo tanto, en esta tesis se aborda primero el problema de la de nici on de agentes normativos aut onomos que sean capaces de deliberar acercaCriado Pacheco, N. (2012). Using Norms To Control Open Multi-Agent Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17800Palanci

A society of mind approach to cognition and metacognition in a cognitive architecture

This thesis investigates the concept of mind as a control system using the "Society of Agents" metaphor. "Society of Agents" describes collective behaviours of simple and intelligent agents. "Society of Mind" is more than a collection of task-oriented and deliberative agents; it is a powerful concept for mind research and can benefit from the use of metacognition. The aim is to develop a self configurable computational model using the concept of metacognition. A six tiered SMCA (Society of Mind Cognitive Architecture) control model is designed that relies on a society of agents operating using metrics associated with the principles of artificial economics in animal cognition. This research investigates the concept of metacognition as a powerful catalyst for control, unify and self-reflection. Metacognition is used on BDI models with respect to planning, reasoning, decision making, self reflection, problem solving, learning and the general process of cognition to improve performance.One perspective on how to develop metacognition in a SMCA model is based on the differentiation between metacognitive strategies and metacomponents or metacognitive aids. Metacognitive strategies denote activities such as metacomphrension (remedial action) and metamanagement (self management) and schema training (meaning full learning over cognitive structures). Metacomponents are aids for the representation of thoughts. To develop an efficient, intelligent and optimal agent through the use of metacognition requires the design of a multiple layered control model which includes simple to complex levels of agent action and behaviours. This SMCA model has designed and implemented for six layers which includes reflexive, reactive, deliberative (BDI), learning (Q-Ieamer), metacontrol and metacognition layers

Exploring the resource recovery potentials of municipal solid waste: a review of solid wastes composting in developing countries

Population explosion, high urbanization and improved living standards have induced rapid changes in quantities and materiacompositions of solid waste generation globally. Until recently solid waste disposal in landfills and open dump sites waconsidered more economical and it is the most widely used methods in developing countries. Hence the potentials in the othealternative methods such as the resource recovery and recycling and their integration into waste management have been scarcelassessed. However, the ever growing challenges posed by the rapidly increasing quantities and compositions of solid wastes ideveloping countries led to the searching for alternative waste disposal methods. In this regard the paper presented an assessmenof the resource potentials of municipal solid waste materials arising from cities in developing countries as a strategy fosustainable solid waste management. Using published data on solid waste composition the paper has identified that there is higpotentials of composting in the solid waste stream from cities in developing countries. In conclusion, it recommended the recoverof organic waste material and papers for composting and the recycling of plastic, metals, textiles and others to explore their resource recovery potentials. This will largely reduce the ultimate quantities of solid waste for disposal and lower the operatincosts. This strategy will achieve sustainable waste management in developing countries. It is hoped that the paper has provided useful guide for wastes management policy decisions in developing countries

Experience representation in information systems

This thesis looks into the ways subjective dimension of experience could be represented in artificial, non-biological systems, in particular information systems. The pivotal assumption is that experience as opposed to mainstream thinking in information science is not equal to knowledge, so that experience is a broader term which encapsulates both knowledge and subjective, affective component of experience, which so far has not been properly embraced by knowledge representation theories. This is the consequence of dominance of behaviourism and later cognitivism in the XXth-century science, which tended to reduce mind and experience respectively to behavioural expressions and discrete states relating mindful creature to external world, meanwhile the processes of knowing to manipulations with symbols. We support the view that traditional knowledge representation approaches will not suffice to embrace the entirety of mental phenomena. We propose that in order to understand, represent and model the thinking and behavioural processes of mindful entities in information systems we need to look into the phenomenon of experience beyond the boundaries of knowledge. At the same time we propose to look at experience in a more structured way and try to capture it in formal terms, making it amenable to symbolic representation, being aware at the same time of innate limitations of symbolic representations compared to the natural representations in biological bodies. Under the paradigm of mind intentionality, which assumes that minds have this special intrinsic feature that they can relate to external word and thus are about external world, it can be asserted that experience is one in all intentional mind state composed of knowledge that is the intentional contents of this state, the world-to-mind relation, meanwhile its inseparable subjective component is composed of subjective feelings of the mindful individual corresponding to this intentional mind states. If so, we propose that experience can be defined as two-dimensional mental phenomena consisting of mental states that have both knowledge and affective component. Consequently we suggest that experience can be represented as pairs of elements of sets K, and A, where K represents knowledge, hence contents of remembered intentional states of mind (i.e. intentional contents of experience), whereas A represents affect, i.e. the subjective qualitative component of experience. iii Importantly, it does not particularly matter if we define experience as a set of mind states or a mind state process for assessing if the overall relation between knowledge and subjective experience that we have outlined above is valid. Whether there is knowing rather then knowledge or experiencing rather than experience which seems increasingly a contemporary principle, remains a fascinating philosophical, ontological to be more specific, question, however it falls beyond the scope of the thesis and therefore we shall not concentrate on it herewith. Furthermore we propose that the subjective component of experience is also intrinsically intentionalistic, but meanwhile the intentionality in case of knowing is directed outward, to the external world, in case of feeling it is directed inwards to the within of the experiencing mindbody. We tap into the contemporary thinking in the philosophy of mind that the primordial, intrinsic intentionalistic capacity of mind is non-linguistic, as there must be other more primordial, non-linguistic form of intentionality that allows human children, as well as other language-capable animals, to learn language in first place. Contemporary cognitive neuroscience suggest that this capacity is tightly related to affect. We also embrace the theories of consciousness and self coming from brain scientists such as Damasio and Panksepp who believe that there is a primordial component of self, a so called protoself composed of the raw feelings coming from within the body, which are representations of bodily states in the mind, and have strictly subjective character. Therefore we can look at this compound of primordial feelings as a mirror in which external world reflects via the interface of the senses. This results in experience that has this conceptually dual, yet united within the conscious mindbody, composition of intentional contents that is knowledge and subjective component that is built up by feelings coming from within the experiencing mindbody. For it is problematic to state sharply either that this composition is dual or united we can refer to these two separately considered aspects of experience either as components or dimensions. In this thesis we pay particular attention to the role the affective component of experience plays in the behaviour of organisms, and we use the concept of rational agency to discuss the relations between agent experience and behaviour. This role is primarily about motivation and experience vividness, i.e. how easily experiential states can be retrieved from memory. The affective dimension of experience determines the drivers for agent action and influences the remembering and forgetting (memory) processes that experience is prone to. We reflect on how the above presented framework could enhance one of the most popular rational agency models: the Believes Desires Intentions model (BDI) based on Bratmann’s account of practical reason that has dominated information science and artificial intelligence literature. Inspired by Davidson, who opposing Hume’s account that the passions (desires) drive action while reason (belief) merely directs its force, concluded that iv “(...) belief and desire seem equally to be causal conditions of action. But (...) desire is more basic in that if we know enough about a person’s desires, we can work out what he believes, while the reverse does not hold.” (Davidson, 2004) we conclude that in so far as BDI model approaches them, desires are sort of beliefs. Indeed a desire in the above sense is a verbalised desire, i.e. in order for a proposition to be included in the deliberation an agent must have internally verbalize it and accept it by which he converts it into a belief. As a result an agent acquires a belief about its desire. Apart from desires made thus explicit and becoming beliefs there are implicit experiential states that directly influence behaviour, these are not embraced by the Desires set in the BDI and other instrumentalist rationality models as these currently do not have adequate forms of representation. If this is so, the BDI models looses its D creating a gap which must be filled in, which we try to do with the subjective dimension of experience. Under such an account each belief, either the proper one or about the desire, represented formally with a proposition should have an extra component added which would stand for the subjective affective state to this belief. Some preliminary suggestions how this could be implemented are proposed and discussed. The central proposition of this thesis states that experience, broadly understood as the entirety of contents and quality of a conscious mind state, can be satisfactorily represented in information systems, and any information system which objective is to emulate natural agent behaviour with satisfactory faithfulness cannot do without a sound experience representation framework. To achieve this it is necessary to realize and accept, based on convincing evidence from neuroscience, that the missing subjective component of experience is affect that forms and integral part of natural agent’s experience, and determines, or at least impacts profoundly the behaviour of natural agents. Relating affect to knowledge would result in a satisfactory approximation of experience. It is to realize as well that the subjective dimension of experience, classified as affect, is not entirely private, subjective epiphenomenal entity but rather can be studied in objective terms as neurological correlates in the brain following account of emotion and affect as fostered by contemporary neuroscience. By identifying affective correlates of intentional contents of states of mind, which build up knowledge, we can exploit a broader concept experience for the purpose of more accurate emulation of natural agents’ thinking process and behaviour in information systems. This thesis presents and discusses a bulk of evidence coming mainly from three fields: information science, philosophy of mind and cognitive neuroscience that led us to the above stated conclusions, as well as establishes a framework for experience representation in information systems

Contributos para suportar o desenvolvimento de sistemas de diálogo

With the increase of technology present in our daily routine, a specific area rose exponentially. Spoken dialogue systems are increasingly popular and useful: they provide an easier and more versatile access to large and diverse sets of information. Nowadays there is a vast knowledge base regarding this topic, as well as different systems capable of performing numerous tasks just by simply processing voice input. There are also an increasing set of tools for their development. Despite recent advances, development of dialog systems continues to be challenging. The main objective of this thesis is to contribute and make possible and simple the development of new dialogue systems for Portuguese: by selecting, adapting and combining existing tools/frameworks. Supported by the enhancements made to the selected basis framework, two different dialog systems were developed: the first is an assistant aimed at a Smart Home environment - one of areas that benefited the most with the development of dialog systems - and the second targeting accessible tourism. The first assistant was developed aligned with the Smart Green Homes project. It implied the definition of scenarios and requirements that later helped defining the ontology and the system. Another requirement for this system was the inclusion of the back-end system developed previously as part of the Smart Green Homes project. The second was aligned with the project ACTION in the area of Tourism. It was developed for users with accessibility needs, e.g., impaired movement or vision.Com o aumento da tecnologia presente na nossa rotina diária, uma área específica subiu exponencialmente. Os sistemas de diálogo são cada vez mais populares e úteis: proporcionam um acesso mais fácil e versátil a grandes e diversificados conjuntos de informação. Hoje em dia existe uma vasta base de conhecimento sobre este tema, bem como diferentes sistemas capazes de executar inúmeras tarefas através do processamento de uma entrada de voz. Há também um conjunto crescente de ferramentas para o seu desenvolvimento. Apesar dos avanços recentes, o desenvolvimento de sistemas de diálogo continua a ser um desafio. O principal objetivo desta tese é contribuir e tornar possível e simples o desenvolvimento de novos sistemas de diálogo que suportem português: selecionando, adaptando e combinando ferramentas existentes. Baseado nas melhorias feitas nas ferramentas bases selecionadas, foram desenvolvidos dois sistemas de diálogo diferentes: o primeiro é um assistente dirigido a um ambiente Smart Home - uma das áreas que mais beneficiou com o desenvolvimento de sistemas de diálogo - e o segundo visando o turismo acessível. O primeiro assistente foi desenvolvido alinhado com o projeto Smart Green Homes. Implicou a definição de cenários e requisitos que mais tarde ajudaram a definir a ontologia e o sistema. Outro requisito para este sistema foi a inclusão do sistema back-end desenvolvido anteriormente como parte do projeto Smart Green Homes. O segundo assistente foi alinhado com o projeto ACTION na área do Turismo. Foi desenvolvido para utilizadores com necessidades de acessibilidade, por exemplo, deficiência motora ou invisualidade.Mestrado em Engenharia de Computadores e Telemátic