This thesis compares the performance of heterogeneous and homogenous swarms. Swarms are defined as particles or agents which react to their environment and fellow particles or agents according to social rules. The weights of three attributes of an individual agent were varied for these experiments: Collision Avoidance with individual agents in the swarm, Center of Mass of the swarm and the parameter that controls Velocity Matching in the swarm. In homogenous swarms, all individuals had the same attribute weights while in heterogeneous swarms weights for one attribute were taken from a normal distribution for the population. These swarms were then given goals on a map to pursue. The maps were two-dimensional grid-surfaces with terrains of open, mountain and swamps. Performance was defined as the number of steps it took for 90% of the swarm to reach its final goal. The results show that heterogeneous swarms outperformed homogenous swarms if the weights for the Center of Mass Weight attribute were heterogeneous in the population. The Collision Avoidance and Matched Velocity attributes showed little performance difference for heterogeneous and homogenous swarms for the parameter weights tested. However, swarms heterogeneous in the Matched Velocity parameter showed substantial performance improvements for the most difficult map.

Agent-oriented software engineering is faced with challenges that impact on the adoption of agent technology by the wider software engineering community. This is generally due to lack of adequate comprehension of the concepts of agent technology. This thesis is based on the premise that the comprehension of the concepts of and the adoption of agent technology can be improved. Two approaches are explored: the first approach is the analysis and structuring of the interactions in multiagent systems; the second approach is sharing of experiences of what works and what does not in agent-oriented software engineering using software patterns. While analysis of interactions in multiagent systems improves the understanding of the behaviour of multiagent systems, sharing multiagent system development experience improves the understanding of the concepts of agent technology as well as the challenges that face the engineering of multiagent systems. It is therefore believed that interaction analysis and experience sharing can enhance the comprehension of agent technology and hence, the adoption of the technology by the wider community of software practitioners. This thesis addresses the challenges facing agent-oriented software engineering by presenting a dedicated approach for developing agent interaction protocols to guide the interactions in a multiagent system; and a comprehensive framework for classifying, analyzing and describing agent-oriented patterns for the purpose of sharing multiagent systems development experiences.

The study of Power TAC is a Multi-Agent competitive simulation test-bed, providing opportunity to simulate research and developments of electronic agents which can manage the tasks of the consumers and energy resources in a virtual energy infrastructure. According to the Power TAC scenario, Plug-in Electrical Vehicles are a special type of consumers that interact with this infrastructure and sometimes with the producers through aggregators. The aim of this study is modeling an intelligent Plug-in Electric vehicle agent for Power TAC that acts as an intermediary between Power TAC grid and vehicle owners. The proposed agent acts autonomously and is capable of making decisions about its energy needs by learning the driving behaviors and other preferences of these vehicle owners in a specified time interval. These agents will be able to make decisions about buying energy from the grid when the charging process is necessary or sell their energy back to the grid when the conditions of the electricity market are sufficiently attractive. The objective of this study is to model a Multi-Agent system for automating the process of charging the plug-in Vehicle Agents in Power TAC scenario by determining the necessary agents and the simulation environment where the agents constructed and simulated. Аs results of this study, different strategies are defined by considering the preferences of the vehicle owners and the conditions of the vehicle; thereby the agents autonomously bid behalf of their user in order to automate the process of charging.

<p>Agentska paradigma predstavlja najprirodniji i najdosledniji&nbsp;postojeći pristup implementaciji distribuiranih sistema. Uz&nbsp;pomoć agenata moguće je u potpunosti realizovati koncept<br />distribuiranih softverskih komponenti, koje će, osim re&scaron;enja&nbsp;zadatka na distribuiranom nivou, pružiti i određenu količinu&nbsp;autonomnosti i inteligencije da bi se zadati cilj ostvario.&nbsp;Agentsko okruženje predstavlja programsko okruženje koje&nbsp;upravlja životnim tokom agenata i obezbeđuje mu sve potrebne&nbsp;mehanizme za realizaciju zadatka. U ovoj doktorskoj disertaciji&nbsp;predložen je model agentskog okruženja baziran na tehnologiji&nbsp;distribuiranih komponenti, koji podržava FIPA specifikaciju i&nbsp;sledeće koncepte: razmenu poruka, mobilnost agenata,&nbsp;sigurnosne mehanizme i direktorijume agenata i servisa. Model&nbsp;agentskog okruženja je implementiran u J2EE tehnologiji.&nbsp;Podržan je sistem plug-in-ova za sve bitne komponente&nbsp;agentskog okruženja (menadžere). Modelovan je i<br />implementiran koncept mobilnih zadataka. Dat je model i&nbsp;implementacija sistema međusobnog uređenja odnosa agentskih&nbsp;centara. Predloženo re&scaron;enje agentskog okruženja verifikovano&nbsp;je na bibliotečkom informacionom sistemu BISIS. Verifikacija&nbsp;je izvr&scaron;ena na sledećim agentskim zadacima: pretraživanje&nbsp;bibliotečke mreže, ocenjivanje kvaliteta zapisa i inteligentna&nbsp;raspodela opterećenja.</p> / <p>Agent technology is one of the most consistent approaches to&nbsp;the distributed computing implementation. Agents can be used&nbsp;to fully implement distributed software component concept.&nbsp;Agents can solve distributed problems utilizing certain degree&nbsp;of autonomy and intelligence. Agent framework represents&nbsp;programming environment that controls agent life cycle and&nbsp;provides all necessary mechanisms for task execution. The&nbsp;subject of the dissertation is formal specification of an agent&nbsp;framework based on distributed component technology. This&nbsp;framework supports FIPA specification and following concepts:&nbsp;message interchange, agent mobility, security and agent and&nbsp;service directory. Agent framework is implemented in J2EE&nbsp;technology. Plug-in system is designed for all key elements of&nbsp;agent framework. Mobile tasks were specified and&nbsp;implemented. Also, inter-facilitator connectivity mechanism is&nbsp;specified and implemented. The framework is verified by a case&nbsp;study on the library information system BISIS. Following agent&nbsp;tasks were performed: library network search, library record&nbsp;quality estimation and intelligent load balansing.&nbsp;</p>

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Past research on multi-agent simulation with cooperative reinforcement learning (RL) for homogeneous agents focuses on developing sharing strategies that are adopted and used by all agents in the environment. These sharing strategies are considered to be reciprocating because all participating agents have a predefined agreement regarding what type of information is shared, when it is shared, and how the participating agent's policies are subsequently updated. The sharing strategies are specifically designed around manipulating this shared information to improve learning performance. This thesis targets situations where the assumption of a single sharing strategy that is employed by all agents is not valid. This work seeks to address how agents with no predetermined sharing partners can exploit groups of cooperatively learning agents to improve learning performance when compared to Independent learning. Specifically, several intra-agent methods are proposed that do not assume a reciprocating sharing relationship and leverage the pre-existing agent interface associated with Q-Learning to expedite learning. The other agents' functions and their sharing strategies are unknown and inaccessible from the point of view of the agent(s) using the proposed methods. The proposed methods are evaluated on physically embodied agents in the multi-agent cooperative robotics field learning a navigation task via simulation. The experiments conducted focus on the effects of the following factors on the performance of the proposed non-reciprocating methods: scaling the number of agents in the environment, limiting the communication range of the agents, and scaling the size of the environment. / Master of Science

In recent years many people have built Personal Assistant Agents, Information Agents and the like, and have simply added them to the operating system as auxiliary applications, without regard to architecture. This thesis argues that an agent architecture, one designed as a sophisticated representation of an individual user, should be embedded deep in the device system software, with at least equal status to the GUI – the graphical user interface. A sophisticated model of the user is then built, drawing upon contemporary Analytical Psychology – the Psychology of Subselves. The Shadowboard Agent architecture is then built upon that user model, drawing both structural and computational implications from the underlying psychology. An XML DTD file named Shadowboard.dtd is declared as a practical manifestation of the semantics of Shadowboard. An implementation of the Shadowboard system is mapped out, via a planned conversion of two existing integrated systems: SlimWinX, an event-driven GUI system; and XSpaces, an object-oriented tuplespace system with Blackboard-like features. The decision making mechanism passes logic terms and contraints between the various sub-agent components (some of which take on the role of Constraint Solvers), giving this agent system some characteristics of a Generalised Constraint Solver. A Shadowboard agent (built using the system) consists of a central controlling autonomous agent named the Aware Ego Agent, and any number of sub-agents, which collectively form an integrated but singular whole agent modelled on the user called the Digital Self. One such whole-agent is defined in a file named DigitalSelf.xml – which conforms to the schema in Shadowboard.dtd - which offers a comprehensive and generic representation of a user’s stance in a 24x7 network, in particular - the Internet. Numerous types of Shadowboard sub-agents are declared.

Um subconjunto importante da pesquisa em sistemas multiagentes (SMA) baseiase no estudo das organizações. A organização define a estrutura do SMA e as regras que os agentes devem seguir, a fim de aumentar a eficiência do sistema. No entanto, dado um domínio, a escolha da organização que melhor resolve o problema ainda é uma questão sem resposta. Assim, abordagens empíricas para a avaliação de organizações são importantes, pois fornecem indícios valiosos sobre os custos e benefícios de diferentes configurações organizacionais, ajudando desenvolvedores e projetistas na definição da organização a ser adotada. Neste contexto, este trabalho, compara e avalia o impacto da mudança de parâmetros organizacionais no desempenho de um SMA, cujo objetivo é competir no cenário Agents on Mars proposto no Multi-Agent Programming Contest (MAPC). / An important subset of multi-agent systems (MAS) are based on the study of organizations. The organization defines the MAS structure and the rules which the agents must follow, increasing the MAS efficiency. Given an application domain, however, the choice of a particular organization that better solves the problem is still an open problem. Therefore, empirical approaches to the evaluation of organizations are important since they provide valuable evidences about the costs and benefits of different organizational settings, helping developers and designers to define the organization to be adopted. In this context, this work compares and evaluates the impact of organizational changes in the performance of a MAS, whose goal is to evolve in the \"Agents on Mars\" scenario proposed in the Multi-Agent Programming Contest (MAPC).

Um subconjunto importante da pesquisa em sistemas multiagentes (SMA) baseiase no estudo das organizações. A organização define a estrutura do SMA e as regras que os agentes devem seguir, a fim de aumentar a eficiência do sistema. No entanto, dado um domínio, a escolha da organização que melhor resolve o problema ainda é uma questão sem resposta. Assim, abordagens empíricas para a avaliação de organizações são importantes, pois fornecem indícios valiosos sobre os custos e benefícios de diferentes configurações organizacionais, ajudando desenvolvedores e projetistas na definição da organização a ser adotada. Neste contexto, este trabalho, compara e avalia o impacto da mudança de parâmetros organizacionais no desempenho de um SMA, cujo objetivo é competir no cenário Agents on Mars proposto no Multi-Agent Programming Contest (MAPC). / An important subset of multi-agent systems (MAS) are based on the study of organizations. The organization defines the MAS structure and the rules which the agents must follow, increasing the MAS efficiency. Given an application domain, however, the choice of a particular organization that better solves the problem is still an open problem. Therefore, empirical approaches to the evaluation of organizations are important since they provide valuable evidences about the costs and benefits of different organizational settings, helping developers and designers to define the organization to be adopted. In this context, this work compares and evaluates the impact of organizational changes in the performance of a MAS, whose goal is to evolve in the \"Agents on Mars\" scenario proposed in the Multi-Agent Programming Contest (MAPC).

The aim and objective of this study was to determine the bond strength of a twostep and a single-step dentin bonding agent and to determine the effect of repeated thermal-cycling from 50C and 550C on the bond strength values of these dentin bonding agents.