Neste trabalho apresentamos um modelo para ambientes inteligentes baseado em organizações de agentes, onde interações entre entidades são associadas a espaços físicos, pessoas carregam dispositivos e se movimentam entre diferentes espaços físicos e cada espaço físico contém definições de interações (comportamentos definidos por normas) próprias do seu contexto. São definidos três componentes deste modelo: (1) modelo conceitual, (2) linguagem de especificação e (3) ambiente de execução. A separação do modelo nestes três componentes traz como principais conseqüências: (1) a ativação de um ambiente inteligente é feita através de um mecanismo de alto nível, (2) a especificação de um ambiente inteligente é independente do domínio de aplicação e (3) as especificações podem ser executadas em mecanismos diferentes de execução. / We introduce a conceptual model for smart environments based on agent organizations where interactions between entities are associated with physical spaces, people (carrying mobile devices) move between different physical spaces and these physical spaces contain definitions of interactions (behaviors defined by norms) related to each context. This model defines three components: (1) conceptual model, (2) language specification, and (3) execution environment. The separation in these three components brings as main consequences: (1) activation of a smart environment is performed through a high-level mechanism, (2) specification of a smart environment is independent of the application domain, and (3) specifications can be performed on different mechanisms of execution.

Esta tese situa-se na área de IA (Inteligência Artificial) aplicada à educação incluindo características interdisciplinares tanto da própria IA como de IE (informática na Educação). Faz-se também necessário constarem, aspectos referentes à Ciência da Computação e Educação a fim de melhor situar a complexidade e a dimensão do trabalho desenvolvido. A utilização de técnicas de IA na elaboração e no desenvolvimento de ambientes de ensino-aprendizagem computadorizados tem se constituído em objeto de investigação por parte dos pesquisadores da área de Informática aplicada à Educação, devido as suas potencialidades. A utilização de agentes na modelagem e no projeto de STI permite-nos resgatar antigos problemas em aberto, como por exemplo a melhoria da interação entre tutor e aluno e a possibilidade de investigação dos processos mentais em nível mais estratificado. A arquitetura descrita nesta tese utiliza a metodologia que vem sendo aplicada ao projeto de STI, onde são contempladas diferentes formas de se trabalhar com um determinado conhecimento (estratégias de ensino e táticas associadas), levando-se em consideração o tipo de usuário que está interagindo com o sistema. A arquitetura, elaborada segundo uma abordagem construtivista, prevê que o tutor seja menos diretivo e menos controlador das ações do aluno. O controle é feito na forma de monitoração para que o tutor funcione como um parceiro, ou seja, como facilitador do trabalho do aluno. Contudo, devido às características da modalidade escolhida para construção do protótipo (jogo educacional), precisamos ter algumas atitudes no tutor que garantam que o sistema não entre em colapso. O que inviabilizaria o trabalho do aluno. Nestas situações críticas, o tutor vai se comportar de maneira mais diretiva. Cabe salientar que a abordagem construtivista não significa dar liberdade total ao aluno nem privá-lo de qualquer tipo de assistência. Portanto, o que deve ser destacado é o grau de interferência do tutor, i.e., o quanto ele interfere no trabalho do aluno e se ele permite ou não que o aluno siga um caminho alternativo àquele que ele tem como o ideal para resolver o problema (heurísticas do tutor sobre o problema e forma de solução). Além destes aspectos educacionais inerentes a todo o projeto de software educacional (necessários num trabalho desta natureza), esta tese está inserida no contexto da pesquisa em agentes cognitivos modelados através de seus estados mentais. É importante salientar que os estados mentais utilizados neste trabalho (crenças, desejos, intenções e expectativas) funcionam como uma metáfora dos estudos mentais humanos. Por exemplo, quando se coloca a crença de um aluno a respeito de "lago", na realidade está se colocando a crença que temos a respeito da crença que o aluno possui a respeito de "lago". O mesmo acontece com os outros estados mentais aqui utilizados. Os diálogos reais foram registrados através de observação direta e posteriormente analisados a fim de se identificar os estados mentais relacionados. Perguntas adicionais foram feitas no sentido de obterem-se mais elementos para auxiliar na inferência do conjunto de estados mentais que o aluno possui naquele momento em que estava jogando. Após a observação de vários alunos jogando, identificou-se um certo padrão nas suas atitudes quando executavam uma ação. Observações sucessivas permitiram delinear o conjunto de estados mentais associados à ação do aluno. Tal conjunto foi utilizado como base para elaboração da coreografia. Estes dados servem de entrada para a construção do modelo do aluno mediante a interação com o tutor. No presente trabalho, nós apresentamos a modelagem de um STI através do uso da tecnologia de agentes utilizando a arquitetura de SMA (Sistemas Multiagentes). O STI é concebido como um SMA híbrido composto por um ambiente reativo (SMAR - Sistema Multiagente Reativo) e um "kernel" cognitivo (SMAC - Sistema Multiagente Cognitivo). O SMAR e o SMAC interagem entre si de para ampliar as informações quantitativas e qualitativas oferecidas aos alunos que utilizam o sistema. Estas informações disponíveis é que irão permitir ao tutor selecionar estratégias de ensino mais adequadas a um determinado tipo de aluno. A principal contribuição desta tese está centrada no "kernel" cognitivo. Nós propomos uma arquitetura para o tutor que permitirá a monitoração de dois alunos trabalhando conjuntamente. Além disso, propomos uma forma de selecionar o comportamento do tutor para oferecer auxílio personalizado aos alunos considerando o perfil de cada um. Esta arquitetura pretende ser uma alternativa de solução para uma questão importante na área de STI: Como o tutor pode selecionar, entre várias estratégias de ensino, a mais adequada para cada perfil de aluno? O grupo de pesquisa no qual este trabalho está inserido (GIA/UFRGS, sob orientação da Prof.a. Rosa Maria Viccari) tem realizado algumas avaliações experimentais, usando STI tradicionais e STI projetados e modelados através de sistemas multiagentes As contribuições científicas listadas no texto deste trabalho possibilitaram que o grupo avançasse sua pesquisa na abordagem mentalística através da criação de uma arquitetura para o tutor e favorecesse a integração do trabalho desenvolvido por Móra et al. [MOR97; MOR98]. A utilização do modelo computacional de agentes criado por Móra et al. gerou a implementação do "kernel" cognitivo. Os desafios inerentes a implementação da arquitetura proposta para o tutor ampliaram as características do ambiente criado por Móra et al. e favorecem a junção de dois trabalhos de tese supervisionados pela mesma orientadora [MOR99]. Portanto, a nova arquitetura proporcionou ganhos tanto para tais pesquisas, como para o avanço das pesquisas desenvolvidas pelo nosso grupo. / The present thesis has been elaborated within the AI (Artificial Intelligence) applied to Education realm, and it brings specific contributions to the STI (Intelligent Tutoring System) area. The use of AI techniques has been investigated by researchers of Computer Science applied to Education, due to its potentialities to improve educational systems. The agents' techniques used in the design of STI allow us to solve old problems opened in the area. For instance, the improvement of the interaction between tutor and student, and the possibility of tracing the mental processes in a more stratified way. The architecture described in this thesis uses the methodology applied to the modern STI projects: multiple strategies for the tutor (i.e., teaching strategies and associated tactics). This approach considers different forms of working with a certain piece of knowledge, and is taken into consideration to create the user profile, as well as to monitor the student interaction with the system. The architecture, designed according to a constructivist approach, expects the tutor to be less directive, and less controller of the student's actions. The control is made by an observation of students' actions by the tutor. The tutor works either as a student's partner or as a facilitator. However, due to the characteristics of the modality chosen for construction of the prototype (educational game), we needed to take some attitudes in the tutor in order to avoid the system to collapse. What would make unfeasible the student's work. In these critical situations, the tutor will behave in more directive way. It fits to point out that the construtivist approach does not mean to give total freedom to the student or to deprive it of any kind of attendance. Therefore, what should be note here is the degree of the tutor's interference, i.e., how it interferes with the student's work using its own set of heuristics. Besides these educational aspects, inherent to a project of Educational software, this thesis is inserted in the context of the research in cognitive agents modelled through their mental states (Believe, Desire, Intention, and Expectation). It is important to point out that the mental states used in this work are as a metaphor of the human mental states. For example, when the student's has a believe regarding "lake", in fact we area talking about belief that we have regarding the belief that the student possesses regarding about "lake". The same happens here with the other mental states used. The real dialogues were registered through direct observation in real situation (students playing with the game). They were analysed in order to identify the mental states connected with the student's actions. Additional questions were asked to obtain more elements to aid us to inference the group of mental states possessed by the student when he/she was playing. Successive observations allowed us to delineate the group of mental states associated to the student's action. Such group was used as a base for the choreography. These data were used as input for the construction to the student's model during the interaction with the tutor. In this work, we have presented the design of an STI with the use of architecture of MAS (Multi-agent System Architecture). The ITS is conceived as a hybrid MAS composed by a RMAS (Reactive Multi-agent System) and a "cognitive kernel" using the CMAS (Cognitive Multi-agent System). The RMAS and the CMAS interact with each other to enlarge the quantitative and qualitative information offered to the students that uses the system. These available information allow the tutor to select teaching strategies more adapted to a certain student type. The main contribution of this thesis is centred in the "cognitive kernel". We propose an architecture for the tutor that will allow the two students to work together. Besides, we propose a way to select the tutor behaviour in order to aid the students considering their personal profile. This architecture intends to be an alternative solution for an important question in ITS research: How can the tutor select, among several teaching strategies, the one that is more suitable for each student profile? The research group in which this work is placed (GIA/UFRGS - Artificial Intelligence Group), under the supervision of Profa. Rosa Maria Viccari, has been doing executing some experimental evaluations, using traditional ITS and ITS modelled through multi-agents systems techniques. The scientific contributions listed in this work allow the group to achive some interesting results in the research of STI using a mental approach. The tutor architecture favoured the integration of the X-BDI (eXecutable Belief Desire, and Intention model)) developed by Móra et al. The use the X-BDI allowed us to implement the "cognitive kernel". The inherent challenges posed by the implementation of the architecture of the tutor refined the XBDI environment. It favours the junction of two thesis works supervised done under the same supervisor[MOR99]. Therefore, the new architecture provided many gains for both researches, as well as for the progress of the research developed by our group.

Redes de sensores sem fio (RSSFs) heterogêneas podem combinar nós estáticos e nós móveis. Os nós móveis podem ainda conter um hardware mais sofisticado quando comparado aos nós estáticos. Veículos aéreos não tripulados (VANTs) podem conferir mobilidade ao nó sensor aumentando a flexibilidade da RSSF onde ele está inserido. Tanto os VANTs quanto outros n´os sensores comuns podem conter uma arquitetura de hardware reconfiguraável, como por exemplo um FPGA, e com isso adquirir um poder computacional diferenciado. RSSFs propiciam um grande e interessante espectro de aplicações possíveis, tais como vigilância aérea, suporte `a segurança pública entre outros. As RSSFs podem ser configuradas através do uso de agentes móveis, que são capazes de migrar carregando as tarefas que serão executadas nos n´os. Neste cenário, este trabalho descreve uma arquitetura de agentes reconfiguráveis para redes de sensores sem fio. Os agentes são capazes de serem executados como um agente puramente em software, ou também como um agente em hardware, de- pendendo do ambiente de execução disponível e do design escolhido. A arquitetura proposta para o agente reconfiguraável apresenta a transparência necessária ao agente para que o resto do sistema não perceba a natureza dos agentes que estão sendo executados na plataforma. Além disso, a arquitetura permite a migração dinâmica de agentes que reconfiguram o sistema também de uma maneira transparente. São mostrados exemplos de casos de uso que demostram a viabilidade de uso da arquitetura proposta e este trabalho ainda mostra a análise realizada sobre estas plataformas. / Heterogeneous wireless sensor networks (WSN) can combine static nodes and mobile nodes. Theses mobile nodes may contain a sophisticated hardware when compared to static nodes. Unmanned aircraft vehicles (UAVs) can confer mobility to the sensor node increasing the flexibility of the WSN to where it is inserted. UAVs as well as other common sensor nodes can have a reconfigurable hardware architecture, as, for example, an FPGA and with this achieve a differentiated computational power. WSNs enable a vast and interesting spectrum of possible applications, like aerial surveillance, public security support, among others. The WSNs can be configured by the use of mobile agents, which are capable of migrating among the nodes, carrying the tasks to be executed and that will be instantiated on a given node. In this scenario, this work describes an architecture of reconfigurable agents to wireless sensor networks. The agents can be implemented purely in software or as a hardware agent, depending on the available execution environment and on the chosen design. The proposed architecture presents the necessary transparency to the agent so that the rest of the system is not aware of the nature of the agents that are implemented on the platform. Furthermore, the architecture enables dynamic migration of agents that reconfigure the system in a transparent way as well. In this work, use cases examples that demonstrate the feasibility of using the proposed architecture are shown, as well as the analysis performed on these platforms.

Neste trabalho é apresentada uma infraestrutura de nível micro-organizacional para sistemas multiagentes. A infraestrutura permite definir e gerenciar papéis e grupos de papéis organizacionais, que caracterizam o nível micro-organizacional das sociedades de agentes, em termos de quatro dimensões organizacionais: estrutural, funcional, dialógica e normativa. As principais características micro-organizacionais suportadas pela infraestrutura são: definição de papéis em termos de objetivos de realização (achievement goals) e objetivos de manutenção (maintenance goals), e seus respectivos planos; definição de normas organizacionais e um mecanismo para imposição das normas (norm enforcement); relações de dependências organizacionais entre papéis e grupos de papéis; mecanismo de reputação para auxiliar os agentes na busca de parceiros para seus objetivos individuais e selecionar parceiros para atingir metas coletivas; processo de reorganização não institucionalizado realizado por iniciativa dos agentes. A infraestrutura é baseada no metamodelo de agentes e artefatos e no conceito de organizações incorporadas (embodied organizations). Como resultado deste trabalho é disponibilizada uma infraestrutura de gerenciamento organizacional, independente de modelo organizacional, desenvolvida utilizando a plataforma CArtAgO que permite tornar a organização acessível aos agentes. / In this work, we present an artifact-based micro-organizational level infrastructure for multi-agent systems. It provides a way to define and manage the organizational roles and groups of roles that characterize the micro-organizational level of agent societies, in terms of the four organizational dimensions: structural, functional, dialogical and normative. The main micro-organizational features supported by the infrastructure are: definition of roles in terms of achievement and maintenance goals, and their corresponding plans; organizational norms and corresponding sanction-based mechanism of norm enforcement; organizational protocols to support the achievement of role goals; relations of organizational dependences between roles and groups of roles; reputation mechanism to help agents to find partners for their individual goals and to select partners to achieve collective goals; reorganization process not institutionalized performed by the initiative of agents. The infrastructure is based on the A & A meta-model and in the concept of embodied organizations. As a result of this work, we provide an organizational management infrastructure, independent of organizational model, developed using the CArtAgO platform that makes the organization accessible to agents.

Submitted by Jessica Andrade (jessicastefanysa@gmail.com) on 2018-06-28T18:00:49Z No. of bitstreams: 1 TELMO.pdf: 5034534 bytes, checksum: d5ff82ed46adf98d29eb0e7b1578bb38 (MD5) / Approved for entry into archive by Margareth Ferreira Pinto (margarethfpinto@hotmail.com) on 2018-07-16T21:35:04Z (GMT) No. of bitstreams: 1 TELMO.pdf: 5034534 bytes, checksum: d5ff82ed46adf98d29eb0e7b1578bb38 (MD5) / Made available in DSpace on 2018-07-16T21:35:04Z (GMT). No. of bitstreams: 1 TELMO.pdf: 5034534 bytes, checksum: d5ff82ed46adf98d29eb0e7b1578bb38 (MD5) Previous issue date: 2015 / O desenvolvimento de sistemas com complexidade necessária a uma abordagem mul- tiagente carrega consigo também aspectos de complexidade relacionados à avaliação dos diferentes níveis e componentes desse sistema. Um sistema multiagente pode ser com- posto por uma série de agentes heterogêneos, que apresentam variabilidade quanto à sua arquitetura interna, modelos utilizados para o seu desenvolvimento, linguagem de programação, de especificação e validação. Agregam-se a isso, contextos específicos de cada solução para com o ambiente para o qual foi projetado. Deste modo, impõem-se mecanismos que permitam estabelecer métricas de avaliação para cada nível do desenvol- vimento de um sistema multiagente, considerando dimensões como organização, comuni- cação entre agentes e os agentes em si. Esta dissertação apresenta como problemática, o estabelecimento de um benchmark para sistemas multiagente dentro do simulador de futebol de robôs Soccer Server 2D. Mais especificamente, este benchmark deve prover métricas e mecanismos de avaliação de esquemas organizacionais multiagente segundo os diferentes cenários que podem se estabelecer dentro da dinâmica de uma partida de futebol. Não obstante, deve-se permitir o estabelecimento de referências de avaliação da coletividade dos times implementados para o Soccer Server 2D, indiferente aos demais níveis de concepção do sistema. / The development of systems with the required complexity for a multi-agent approach, also carries complexity aspects related to the evaluation of different levels and compo- nents of such a system. A multi-agent system can be composed of a series of hetero- geneous agents, which have variability regarding its internal architecture, models used for its development, programming language, specification and validation. Added to this, are situated the particular contexts of each solution towards the environment for which it is designed. Therefore, it is needed mechanisms to establish evaluation metrics for each multi-agent system development level, taking into account dimensions such as or- ganization, communication between agents and the agents themselves. This dissertation presents as a problem, establish a benchmark for multi-agent systems within the robot soccer simulator Soccerserver 2D. Specifically, this benchmark should provide metrics and evaluation mechanisms of multi-agent organization schemes according to different scenarios that can be established within the dynamics of a football match . Nevertheless, it should be allowed the establishment of assessment referrals for the Robocup teams collectivity, regardless to other levels of system design.

We investigate the use of self-assembly in a robotic system as a means of responding<p>to different environmental contingencies. Self-assembly is the mechanism through which<p>agents in a multi-robot system autonomously form connections with one another to create<p>larger composite robotic entities. Initially, we consider a simple response mechanism<p>that uses stochastic self-assembly without any explicit control over the resulting morphology<p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

La complexité et l'ampleur des scénarios de l'Intelligence Ambiante impliquent que des attributs tels que l'expressivité de modelisation, la flexibilité de representation et de deploiement et la facilité de configuration et de developpement deviennent des caracteristiques centrales pour les systèmes de gestion de contexte. Cependant, les ouvrages existants semblent explorer ces attributs orientés-developpement a un faible degré.Notre objectif est de créer un intergiciel de gestion de contexte flexible et bien configurable, capable de répondre aux différents scenarios. A cette fin, notre solution est construite a base de techniques et principes du Web Semantique (WS) et des systèmes multi-agents (SMA).Nous utilisons le WS pour proposer un noveau meta-modèle de contexte, permettant une modelisation expressive et extensible du contenu, des meta-proprietés (e.g. validité temporelle, parametres de qualité) et des dépendances (e.g. les contraintes d'integrité) du contexte.De plus, une architecture a base de SMA et des composants logiciels, ou chaque agent encapsule un aspect fonctionnel du processus de gestion de contexte (acquisition, coordination, diffusion, utilisation) est developpée.Nous introduisons un nouveau moyen de structurer le deploiement d'agents selon les dimensions du modèle de contexte de l'application et nous elaborons des politiques déclaratives gouvernant le comportement d'adaptation du provisionnement contextuel des agents. Des simulations d'un scenario d'université intelligente montrent que un bon outillage construit autour de notre intergiciel peut apporter des avantages significatifs dans la génie des applications sensibles au contexte. / The complexity and magnitude of Ambient Intelligence scenarios imply that attributes such as modeling expressiveness, flexibility of representation and deployment, as well as ease of configuration and development become central features for context management systems.However, existing works in the literature seem to explore these development-oriented attributes at a low degree.Our goal is to create a flexible and well configurable context management middleware, able to respond to different scenarios. To this end, our solution is built on the basis of principles and techniques of the Semantic Web and Multi-Agent Systems.We use the Semantic Web to provide a new context meta-model, allowing for an expressive and extensible modeling of content, meta-properties (e.g. temporal validity, quality parameters) and dependencies (e.g. integrity constraints).In addition, we develop a middleware architecture that relies on Multi-Agent Systems and a service component based design. Each agent of the system encapsulates a functional aspect of the context provisioning processes (acquisition, coordination, distribution, use).We introduce a new way to structure the deployment of agents depending on the multi-dimensionality aspects of the application's context model. Furthermore, we develop declarative policies governing the adaptation behavior of the agents managing the provisioning of context information.Simulations of an intelligent university scenario show that appropriate tooling built around our middleware can provide significant advantages in the engineering of context-aware applications.

L’Internet des Objets (IoT) vise à créer un eco-système global et ubiquitaire composé d’un grand nombre d’objets hétérogènes. Afin d’atteindre cette vision, le World Wide Web apparaît comme un candidat adapté pour interconnecter objets et services à la couche applicative en un Web des Objets (WoT).Cependant l’évolution actuelle du WoT produit des silos d’objets et empêche ainsi la mise en place de cette vision. De plus, même si le Web facilite la composition d’objets et services hétérogènes, les approches existantes produisent des compositions statiques incapables de s’adapter à des environnements dynamiques et des exigences évolutives. Un autre défi est à relever: permettre aux personnes d’interagir avec le vaste, évolutif et hétérogène IoT.Afin de répondre à ces limitations, nous proposons une architecture pour IoT ouvert et autogouverné, constitué de personnes et d’objets situés, en interaction avec un environnement global via des plateformes hétérogènes. Notre approche consiste de rendre les objets autonomes et d’appliquer la métaphore des réseaux sociaux afin de créer des réseaux flexibles de personnes et d’objets. Nous fondons notre approche sur les résultats issus des domaines des multi-agents et du WoT afin de produit un WoT Social.Notre proposition prend en compte les besoins d’hétérogénéité, de découverte et d’interaction flexible dans l’IoT. Elle offre également un coût minimal pour les développeurs et les utilisateurs via différentes couches d’abstraction permettant de limité la complexité de cet éco-système. Nous démontrons ces caractéristiques par la mise en oeuvre de plus scénarios applicatifs. / The Internet of Things (IoT) aims to create a global ubiquitous ecosystem composed of large numbers of heterogeneous devices. To achieve this vision, the World Wide Web is emerging as a suitable candidate to interconnect IoT devices and services at the application layer into a Web of Things (WoT).However, the WoT is evolving towards large silos of things, and thus the vision of a global ubiquitous ecosystem is not fully achieved. Furthermore, even if the WoT facilitates mashing up heterogeneous IoT devices and services, existing approaches result in static IoT mashups that cannot adapt to dynamic environments and evolving user requirements. The latter emphasizes another well-recognized challenge in the IoT, that is enabling people to interact with a vast, evolving, and heterogeneous IoT.To address the above limitations, we propose an architecture for an open and self-governed IoT ecosystem composed of people and things situated and interacting in a global environment sustained by heterogeneous platforms. Our approach is to endow things with autonomy and apply the social network metaphor to createflexible networks of people and autonomous things. We base our approach on results from multi-agent and WoT research, and we call the envisioned IoT ecosystem the Social Web of Things.Our proposal emphasizes heterogeneity, discoverability and flexible interaction in the IoT. In the same time, it provides a low entry-barrier for developers and users via multiple layers of abstraction that enable them to effectively cope with the complexity of the overall ecosystem. We implement several application scenarios to demonstrate these features.

Agent-oriented software engineering is a new software engineering paradigm that is ideally suited to the analysis and design of complex systems. Open distributed environments place a growing demand on complex systems to be adaptive as well. Complex systems that can learn from and adapt to dynamically changing environments are called complex adaptive systems. These systems are characterized by emergent behaviour caused by interactions between system components and the environment. Agent-oriented software engineering methodologies attempt to control emergence during analysis and design by engineering the complex system in such a way that the correct emergent behaviour results during run-time. In a complex adaptive system however, emergent behaviour cannot be predicted during analysis and design, as it evolves only after implementation. By restricting emergent behaviour, as is done in most agent-oriented software engineering approaches, a complex system cannot be fully adaptive as well. We propose the BaBe methodology that will enable a complex system to be adaptive by learning from its environment and modifying its behaviour during run-time. This methodology adds a run-time emergence model consisting of distributed Bayesian behaviour networks to the agent-oriented software engineering lifecycle. These networks are initialised by the human software engineer during analysis and design and deployed by Bayesian agencies (also complex adaptive systems). The Bayesian agents are simple, and collectively they implement distributed Bayesian behaviour networks. These networks, being specialized Bayesian networks, enable the Bayesian agents to collectively mine relationships between emergent behaviours and the interactions that caused them to emerge, in order to adapt the behaviour of the system. The agents are organized into heterarchies of agencies, where each agency activates one or more component behaviour depending on the inference in the underlying Bayesian behaviour network. These agencies assist the human software engineer to bridge the gap between the implementation and the understanding of emergent behaviour in complex adaptive systems. Due to the simplicity of the agents and the minimal communication amongst them, they can be implemented using a commercially available component architecture. We describe a prototype implementation of the Bayesian agencies using Sun’s Enterprise JavaBeans™ component architecture. / Thesis (PhD (Computer Science))--University of Pretoria, 2005. / Computer Science / unrestricted

Environmentally conscious construction has received a significant amount of research attention during the last decades. Even though construction literature is rich in studies that emphasize the importance of environmental impact during the construction phase, most of the previous studies failed to combine environmental analysis with other project performance criteria in construction. This is mainly because most of the studies have overlooked the multi-objective nature of construction projects. In order to achieve environmentally conscious construction, multi-objectives and their relationships need to be successfully analyzed in the complex construction environment. The complex construction system is composed of changing project conditions that have an impact on the relationship between time, cost and environmental impact (TCEI) of construction operations. Yet, this impact is still unknown by construction professionals. Studying this impact is vital to fulfill multiple project objectives and achieve environmentally conscious construction. This research proposes an analytical framework to analyze the impact of changing project conditions on the relationship of TCEI. This study includes green house gas (GHG) emissions as an environmental impact category. The methodology utilizes multi-agent systems, multi-objective optimization, analytical network process, and system dynamics tools to study the relationships of TCEI and support decision-making under the influence of project conditions. Life cycle assessment (LCA) is applied to the evaluation of environmental impact in terms of GHG. The mixed method approach allowed for the collection and analysis of qualitative and quantitative data. Structured interviews of professionals in the highway construction field were conducted to gain their perspectives in decision-making under the influence of certain project conditions, while the quantitative data were collected from the Florida Department of Transportation (FDOT) for highway resurfacing projects. The data collected were used to test the framework. The framework yielded statistically significant results in simulating project conditions and optimizing TCEI. The results showed that the change in project conditions had a significant impact on the TCEI optimal solutions. The correlation between TCEI suggested that they affected each other positively, but in different strengths. The findings of the study will assist contractors to visualize the impact of their decision on the relationship of TCEI.