Reference Framework and Research Agenda

Cloud Computing is a topic that has gained momentum in the last years. Current studies show that an increasing number of companies is evaluating the promised advantages and considering making use of cloud services. In this paper we investigate the phenomenon of cloud computing and its importance for the operation of ERP systems. We argue that the phenomenon of cloud computing could lead to a decisive change in the way business software is deployed in companies. Our reference framework contains three levels (IaaS, PaaS, SaaS) and clarifies the meaning of public, private and hybrid clouds. The three levels of cloud computing and their impact on ERP systems operation are discussed. From the literature we identify areas for future research and propose a research agenda

Modelação Comportamental de Agentes Inteligentes

Os estudos mais recentes identificam as áreas portuárias como um alvo provável de atividade terrorista, não só devido à importância que representam para o comércio mundial mas pela dificuldade em monitorizar e responder em tempo útil a qualquer ameaça com origem na superfície aquática. O grupo de trabalho DAT-POW, da NATO, através do seu projeto SAFE-PORT tem como objetivo a criação de um simulador que auxilie na implementação de dispositivos de defesa portuária. Neste sentido, pretende-se reduzir a susceptibilidade das infraestruturas portuárias em sofrerem um ataque terrorista que afecte o normal funcionamento da mesma. Assim, o projecto SAFE-PORT compreende um módulo de ameaças, na qual esta dissertação se insere, cujo propósito é simular o comportamento de agentes terroristas durante o seu ataque à infraestrutura portuária. Da análise da reacção do dispositivo defensivo, perante esta ameaça, é esperada a capacidade de identificar lacunas no mesmo, potenciando a redução da taxa de sucesso dos ataques subsequentes através de uma optimização do sistema de defesa existente. O módulo de ameaças é constituído por diferentes agentes, responsáveis por executarem ataques de superfície e sub-superfície. O presente trabalho comporta a criação de um modelo comportamental de agentes inteligentes, responsáveis por ataques de sub-superfície. Face à inexistência de incidentes em que tenham sido identificados este tipo de agentes, a criação dos modelos supramencionados depende de um conhecimento da dinâmica própria de acções de mergulho, assim como de técnicas de reprodução desse comportamento num ambiente computacional. Deste modo, a modelação comportamental destes agentes apresenta: uma análise morfológica do terrorista, por forma a facilitar o estabelecimento de pressupostos necessários à elaboração dos perfis; uma proposta de perfil de ataque criado a partir do modelo de máquinas de estado híbridas; o planeamento de um exercício real de obtenção de dados, que permita a otimização dos perfis de ataque propostos.Recent studies identify the port areas as a likely target of terrorist activity, not only because of the importance they pose to the world trade but also because of the difficulty to monitor and respond in timely fashion to any threat originating from water surface. The workgroup DAT-POW through the project SAFE-PORT aims to create a simulator to assist in the implementation of harbour defence systems. In this sense, the intention is to reduce the susceptibility of port infrastructure in suffering a terrorist attack that affects the normal functioning of the same. The project SAFE-PORT comprises a threats module whose purpose is to simulate the behaviour of agents during the terrorist attack on its infrastructure. The analysis of how the system reacts to threats, is expected contribute to identify gaps on it, empowering the reduction of the success rate of subsequent attacks by optimizing the existing defence system. The threat module is constituted by different agents responsible for executing surface and sub-surface attacks. This work involves the creation of a behavioural model of intelligent agents, responsible for sub-surface attacks. In the absence of incidents on which have been identified such agents, the creation of the models mentioned above depends on a knowledge of the dynamics of diving actions as well as techniques of reproducing this behaviour in a computer environment. Therefore, the behaviour modelling of these agents presents: A morphological analysis of the terrorist in order to facilitate the establishment of assumptions necessary for the preparation of the profiles; a proposed attack profile created from the hybrid state machine model; the planning a real data collection exercise, enabling the optimization of the proposed attack profiles

Hybrid state machines with timed synchronization for multi-robot system specification

In multi-robot systems such as in the RoboCup, the need for precise modeling or specification of agent behaviors arises due to the high complexity of the robot agent interactions and the dynamics of the environment. Since the behavior of agents usually can be understood as driven by external events and internal states, it is obvious to model multiagent systems by state transition diagrams. The corresponding formalisms come equipped with a formal semantics which is advantageous. In this paper, a combination of UML statecharts and hybrid automata is proposed, allowing formal system specification on different levels on abstraction on the one hand, and expressing real-time system behavior with continuous variables on the other hand. One important aspect of multi-robot systems is the need of coordination and hence synchronization of behavior. For both, statecharts and hybrid automata, usually it is assumed that synchronization takes zero time. This is sometimes unrealistic. Therefore, a new notation and implementation of synchronization is proposed here, which overcomes this problem. The proposed method is illustrated with a case study from the RoboCup domain. An example from an industrial application is also shown