Intelligent Agents - a Tool for Modeling Intermediation and Negotiation Processes

Many contemporary problems as encountered in society and economy require advanced capabilities for evaluation of situations and alternatives and decision making, most of the time requiring intervention of human agents, experts in negotiation and intermediation. Moreover, many problems require the application of standard procedures and activities to carry out typical socio-economic processes (for example by employing standard auctions for procurement or supply of goods or convenient intermediation to access resources and information). This paper focuses on enhancing knowledge about intermediation and negotiation processes in order to improve quality of services and optimize performances of business agents, using new computational methods that combine formal methods with intelligent agents paradigm. Taking into account their modularity and extensibility, agent systems allow facile, standardized and seamless integration of negotiation protocols and strategies by employing declarative and formal representations specific to computer science.Business processes, Intelligent Agents, Intermediation and Negotiation, Formal Models.

Securing open multi-agent systems governed by electronic institutions

One way to build large-scale autonomous systems is to develop an open multi-agent system using peer-to-peer architectures in which agents are not pre-engineered to work together and in which agents themselves determine the social norms that govern collective behaviour. The social norms and the agent interaction models can be described by Electronic Institutions such as those expressed in the Lightweight Coordination Calculus (LCC), a compact executable specification language based on logic programming and pi-calculus. Open multi-agent systems have experienced growing popularity in the multi-agent community and are expected to have many applications in the near future as large scale distributed systems become more widespread, e.g. in emergency response, electronic commerce and cloud computing. A major practical limitation to such systems is security, because the very openness of such systems opens the doors to adversaries for exploit existing vulnerabilities. This thesis addresses the security of open multi-agent systems governed by electronic institutions. First, the main forms of attack on open multi-agent systems are introduced and classified in the proposed attack taxonomy. Then, various security techniques from the literature are surveyed and analysed. These techniques are categorised as either prevention or detection approaches. Appropriate countermeasures to each class of attack are also suggested. A fundamental limitation of conventional security mechanisms (e.g. access control and encryption) is the inability to prevent information from being propagated. Focusing on information leakage in choreography systems using LCC, we then suggest two frameworks to detect insecure information flows: conceptual modeling of interaction models and language-based information flow analysis. A novel security-typed LCC language is proposed to address the latter approach. Both static (design-time) and dynamic (run-time) security type checking are employed to guarantee no information leakage can occur in annotated LCC interaction models. The proposed security type system is then formally evaluated by proving its properties. A limitation of both conceptual modeling and language-based frameworks is difficulty of formalising realistic policies using annotations. Finally, the proposed security-typed LCC is applied to a cloud computing configuration case study, in which virtual machine migration is managed. The secrecy of LCC interaction models for virtual machine management is analysed and information leaks are discussed

Uma nova abordagem para a implementação de um sistema multiagente para a configuração e o monitoramento da produção de pequenas séries

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Automação e Sistemas, Florianópolis, 2014A Produção de Pequenas Séries (PPS) é um tipo de manufatura caracterizado pela alta diversidade de produtos a serem produzidos associada a tamanhos de lotes reduzidos - possivelmente unitários. Neste sistema de produção as tecnologias empregadas para configuração e monitoramento do processo devem priorizar a produção sem defeitos, inclusive no primeiro item do lote, que pode ser o único. Falhas neste sistema de produção ou defeitos inseridos nos produtos facilmente inviabilizam economicamente todo o lote. Neste contexto, a linha de produção deve ser capaz de efetuar uma troca rápida de configuração para produzir um novo lote em um cenário de vários lotes de tamanho reduzido. É preciso também garantir completo monitoramento da produção do lote, sem falhas, ou quando ocorrer uma falha, ações corretivas devem ser executadas imediatamente. As pesquisas recentes demonstram que sistemas baseados em agentes é uma abordagem promissora para o cenário da PPS. Diante disso, a contribuição desta tese é a apresentação de uma nova Arquitetura de Referência para a implementação de Sistemas Multiagente na configuração e monitoramento da Produção de Pequenas Séries. A abordagem propõe uma Arquitetura de Referência, chamada MAS4SSP, baseada em uma solução unificada, sinérgica e com alto nível de abstração. Para garantir isto, a abordagem emprega como Modelo de Referência o framework JaCaMo que segue o paradigma orientado a multiagente (MAOP). A integração com a linha de produção é realizada com o emprego da tecnologia de comunicação Web Service que é utilizada pelo Sistema Multiagente (cliente) e por um sistema SCADA baseado em aplicação Web, o ScadaBR (servidor). A interface com o usuário pode ser desenvolvida como um recurso adicional na plataforma JaCaMo, ou pode ser realizada uma integração com sistemas legados de produção (como ERP, PCP, MRP) utilizando também a tecnologia de Web Service. Além da Arquitetura de Referência a tese apresenta um Modelo Genérico de Modelagem e Implementação que serve como guia para o desenvolvedor. Esta abordagem foi instanciada em um experimento simulado no contexto de uma PPS de Placas de Circuito Impresso (PCI). Por fim, os resultados e as conclusões sobre a Arquitetura de Referência e o Modelo Genérico de Modelagem e Implementação são apresentados em conjunto com sugestões de trabalhos futuros.Abstract: Small Series Production (SSP) is a type of manufacturing characterized by a high diversity of products to be produced associated with a reduced batch sizes - possibly unitary. In this production system, the technologies employed for process setup and monitoring must prioritize production without defects, including the first item of the lot, which may be the one. Faults in this production system or defects in the product easily become the whole batch economically unfeasible. In this context, the production line should be able to monitor the process and make a quick change of the configuration to produce a new batch in a scenario of several batches with small sizes. The system should also ensure the batch production without failure or when a fault occurs, the corrective actions must be executed immediately. Recent research shows that agent-based systems are a promising approach for the SSP. The contribution of this thesis is the presentation of a new Reference Architecture for the implementation of Multi-Agent Systems to setup and monitoring Small Series Production. The approach proposes a Reference Architecture, called MAS4SSP, based on a unified, synergistic and high level of abstraction solution. To ensure this, the approach employs as a Reference Model the JaCaMo framework that follows the Multi-Agent Oriented Paradigm (MAOP). The integration with the production line is realized with the use of Web Service as communication technology between the Multi-Agent System (client) and a SCADA system - ScadaBR (server). The user interface can be developed as an additional resource in JaCaMo platform or can be an integration system with legacy production systems (such as ERP, MES, MRP) also using Web Service. Beyond the Reference Architecture, this thesis presents a Generic Modeling and Implementation Model which serves as a guide for the developer and that was instantiated in a controlled experiment - a SSP line of Printed Circuit Boards (PCB). Finally, the conclusions and perspectives about the Reference Architecture and the Generic Modeling and Implementation Model are presented together with suggestions for future works

Multi-agent communication for the realization of business-processes

As Internet and information technologies expand further into daily business activities, new solutions and techniques are required to cope with the growing complexity. One area that has gained attention is systems and organizations interoperability and Service Oriented Architectures (SOA). Web Services have grown as a preferred technology in this area. Although these techniques have proved to solve problems of low level integration of heterogeneous systems, there has been little advance at higher levels of integration like how to rule complex conversations between participants that are autonomous and cannot depend on some ruling or orchestrating system. Multi-agent technology has studied techniques for content-rich communication, negotiation, autonomous problem solving and conversation protocols. These techniques have solved some of the problems that emerge when integrating autonomous systems to perform complex business processes. The present research work intends to provide a solution for the realization of complex Business Process between heterogeneous autonomous participants using multi-agent technology. We developed an integration of Web Services and agent-based technologies along with a model for creating conversation protocols that respect the autonomy of participants. A modeling tool has been developed to create conversation protocols in a modular and reusable manner. BDI-Agents implementations that communicate over Web Services are automatically generated out of these models.Internet und Informationstechnik finden immer mehr Verwendung in alltäglichen Geschäftsaktivitäten und als Folge dessen, werden neue Lösungen und Verfahren gebraucht, um der steigenden Komplexität gerecht zu werden. Insbesondere Bereiche wie System- und Organizations- Interoperabilität, wie auch dienst-orientierte Architekturen (SOA) haben demzufolge mehr Aufmerksamkeit bekommen. Dabei sind Web Services zur bevorzugten Technologie geworden. Tatsächlich haben diese Techniken Probleme in niedrigeren Ebenen gelöst, die beim lntegrieren von heterogenen Systemen entstehen. Allerdings gab es bisher weniger Fortschritte in höheren Ebenen, wie der Regelung von komplexen Dialogen zwischen Teilnehmern, die aufgrund ihrer Autonomie, sich nicht nach anderen kontrollierenden oder orchestrierenden Systemen richten lassen. Multiagenten-Systeme haben Bereiche wie inhaltreiche Kommunikation, Handel, autonome Problemlösung und Interaktionsprotokolle im Detail geforscht. Diese Techniken haben Probleme gelöst, die beim Ausführen von komplexen Geschäftsprozessen auftreten. Die vorliegende Doktorarbeit beabsichtigt, mit Verwendung von Multiagenten-Technologien, eine Lösung für die Umsetzung von komplexen Geschäftsprozessen zwischen heterogenen autonomen Teilnehmern bereitzustellen. Wir haben eine Integrationslösung für Web Services und agenten-basierte Technologien zur Verfügung gestellt, zusammen mit einem Model für die Erstellung von Interaktions-Protokollen, die die Autonomie der Teilnehmer berücksichtigt. Ein Modellierungstool wurde entwickelt, um modulare und wiederverwendbare Interaktionsprotokolle gestalten zu können. Aus diesen Modellen kann man auch Implementierungen automatisch erzeugen lassen, welche BDI-Agenten, die über Web Services kommunizieren, verwenden