Supporting software evolution in agent systems

Software maintenance and evolution is arguably a lengthy and expensive phase in the life cycle of a software system. A critical issue at this phase is change propagation: given a set of primary changes that have been made to software, what additional secondary changes are needed to maintain consistency between software artefacts? Although many approaches have been proposed, automated change propagation is still a significant technical challenge in software maintenance and evolution. Our objective is to provide tool support for assisting designers in propagating changes during the process of maintaining and evolving models. We propose a novel, agent-oriented, approach that works by repairing violations of desired consistency rules in a design model. Such consistency constraints are specified using the Object Constraint Language (OCL) and the Unified Modelling Language (UML) metamodel, which form the key inputs to our change propagation framework. The underlying change propagation mechanism of our framework is based on the well-known Belief-Desire-Intention (BDI) agent architecture. Our approach represents change options for repairing inconsistencies using event-triggered plans, as is done in BDI agent platforms. This naturally reflects the cascading nature of change propagation, where each change (primary or secondary) can require further changes to be made. We also propose a new method for generating repair plans from OCL consistency constraints. Furthermore, a given inconsistency will typically have a number of repair plans that could be used to restore consistency, and we propose a mechanism for semi-automatically selecting between alternative repair plans. This mechanism, which is based on a notion of cost, takes into account cascades (where fixing the violation of a constraint breaks another constraint), and synergies between constraints (where fixing the violation of a constraint also fixes another violated constraint). Finally, we report on an evaluation of the approach, covering both effectiveness and efficiency

A model-driven framework for engineering multiagent systems

This dissertation presents the Bochica framework for Agent-Oriented Software Engineering (AOSE). The framework’s task in the software development process is (i) to capture the design decisions for a system under consideration on a platform-independent level of abstraction and (ii) to project this design to a target platform. Bochica goes beyond the state-of-the-art in AOSE as it combines the benefits of a platform-independent approach with the possibility to address concepts of custom application domains and execution environments. Several extension interfaces are specified to enable the customization of the underlying modeling language to the engineer’s needs. Bochica is accompanied by an iterative adaptation process to gradually incorporate extensions. Conceptual mappings for projecting Bochica models to executable code are specified. In order to enable Bochica for modeling agents that inhabit semantically-enhanced virtual worlds, an according extension model is proposed. Finally, a model-driven reverse engineering approach for lifting the underlying design of already implemented Multiagent System (MAS) to the platform-independent layer is introduced. The framework has been successfully evaluated for designing intelligent agents that operate a virtual production line as well as for extracting the underlying design of an already implemented MAS. The evaluation results show that the Bochica approach to AOSE contributes to overcome the gap between design and code.Diese Arbeit präsentiert das Bochica Rahmenwerk für agentenorientierte Softwareentwicklung. Die Aufgabe des Rahmenwerks ist es, die Designentscheidungen für ein IT-System auf einer plattformunabhängigen Ebene festzuhalten und auf eine Zielplattform abzubilden. Bochica erweitert den Stand der Wissenschaft der agentenorientierten Softwareentwicklung durch die Kombination von plattformunabhängigen und plattformspezifischen Eigenschaften. Zu diesem Zweck werden konzeptionelle Schnittstellen für die Anpassung an benutzerspezifische Anwendungsdomänen und Ausführungsumgebungen spezifiziert. Ein iterativer Adaptionsprozess ermöglicht die schrittweise Integration von neuen Konzepten. Für die Projektion von Bochica-Modellen auf eine Agentenplattform werden entsprechende Abbildungsregeln spezifiziert. Um das Bochica Rahmenwerk für die Modellierung von Agenten in semantisch annotierten virtuellen Welten anzupassen wird eine entsprechende Erweiterung eingeführt. Abschließend wird ein modellgetriebener Ansatz für die Extraktion des zugrundeliegenden Designs eines bereits implementierten Agentensystems auf die platformunabhängige Ebene vorgestellt. Bochica wurde in zwei Fallstudien für die Modellierung von Agenten in einer virtuelle Fabrikumgebung und die Extraktion des Designs eines bereits implementierten Agentensystems evaluiert. Die Evaluierungsergebnisse zeigen, daß das Rahmenwerk die Lücke zwischen einem plattformunabhängigen agentenorientiertem Design und der Zielplattform effektiv verringert

eXtended Reality for Education and Training

L'abstract è presente nell'allegato / the abstract is in the attachmen

Coalition based approach for shop floor agility – a multiagent approach

Dissertation submitted for a PhD degree in Electrical Engineering, speciality of Robotics and Integrated Manufacturing from the Universidade Nova de Lisboa, Faculdade de Ciências e TecnologiaThis thesis addresses the problem of shop floor agility. In order to cope with the disturbances and uncertainties that characterise the current business scenarios faced by manufacturing companies, the capability of their shop floors needs to be improved quickly, such that these shop floors may be adapted, changed or become easily modifiable (shop floor reengineering). One of the critical elements in any shop floor reengineering process is the way the control/supervision architecture is changed or modified to accommodate for the new processes and equipment. This thesis, therefore, proposes an architecture to support the fast adaptation or changes in the control/supervision architecture. This architecture postulates that manufacturing systems are no more than compositions of modularised manufacturing components whose interactions when aggregated are governed by contractual mechanisms that favour configuration over reprogramming. A multiagent based reference architecture called Coalition Based Approach for Shop floor Agility – CoBASA, was created to support fast adaptation and changes of shop floor control architectures with minimal effort. The coalitions are composed of agentified manufacturing components (modules), whose relationships within the coalitions are governed by contracts that are configured whenever a coalition is established. Creating and changing a coalition do not involve programming effort because it only requires changes to the contract that regulates it

National Wind Tunnel Complex (NWTC)

The National Wind Tunnel Complex (NWTC) Final Report summarizes the work carried out by a unique Government/Industry partnership during the period of June 1994 through May 1996. The objective of this partnership was to plan, design, build and activate 'world class' wind tunnel facilities for the development of future-generation commercial and military aircraft. The basis of this effort was a set of performance goals defined by the National Facilities Study (NFS) Task Group on Aeronautical Research and Development Facilities which established two critical measures of improved wind tunnel performance; namely, higher Reynolds number capability and greater productivity. Initial activities focused upon two high-performance tunnels (low-speed and transonic). This effort was later descoped to a single multipurpose tunnel. Beginning in June 1994, the NWTC Project Office defined specific performance requirements, planned site evaluation activities, performed a series of technical/cost trade studies, and completed preliminary engineering to support a proposed conceptual design. Due to budget uncertainties within the Federal government, the NWTC project office was directed to conduct an orderly closure following the Systems Design Review in March 1996. This report provides a top-level status of the project at that time. Additional details of all work performed have been archived and are available for future reference

Lean Six Sigma in Cameron Sense Examining improvement management in a highly technical environment for removing waste, defects and unwanted variations.

Masteroppgave økonomi og administrasjon- Universitetet i Agder, 2015(Konfidensiell til/confidential until 01.07.2020

An executable Theory of Multi-Agent Systems Refinement

Complex applications such as incident management, social simulations, manufacturing applications, electronic auctions, e-institutions, and business to business applications are pervasive and important nowadays. Agent-oriented methodology is an advance in abstractionwhich can be used by software developers to naturally model and develop systems for suchapplications. In general, with respect to design methodologies, what it may be important tostress is that control structures should be added at later stages of design, in a natural top-downmanner going from specifications to implementations, by refinement. Too much detail (be itfor the sake of efficiency) in specifications often turns out to be harmful. To paraphrase D.E.Knuth, “Premature optimization is the root of all evil” (quoted in ‘The Unix ProgrammingEnvironment’ by Kernighan and Pine, p. 91).The aim of this thesis is to adapt formal techniques to the agent-oriented methodologyinto an executable theory of refinement. The justification for doing so is to provide correctagent-based software by design. The underlying logical framework of the theory we proposeis based on rewriting logic, thus the theory is executable in the same sense as rewriting logicis. The storyline is as follows. We first motivate and explain constituting elements of agentlanguages chosen to represent both abstract and concrete levels of design. We then proposea definition of refinement between agents written in such languages. This notion of refinement ensures that concrete agents are correct with respect to the abstract ones. The advantageof the definition is that it easily leads to formulating a proof technique for refinement viathe classical notion of simulation. This makes it possible to effectively verify refinement bymodel-checking. Additionally, we propose a weakest precondition calculus as a deductivemethod based on assertions which allow to prove correctness of infinite state agents. Wegeneralise the refinement relation from single agents to multi-agent systems in order to ensure that concrete multi-agent systems refine their abstractions. We see multi-agent systemsas collections of coordinated agents, and we consider coordination artefacts as being basedeither on actions or on normative rules. We integrate these two orthogonal coordinationmechanisms within the same refinement theory extended to a timed framework. Finally, wediscuss implementation aspects.LEI Universiteit LeidenFoundations of Software Technolog