Catálogo de publicaciones - libros

Agent communication is one of the most important aspects in the multi-agent system area. In recent years, several works have been developed that are related to the agent communication problem.

This paper presents a new method for agent and agent platform communication in accordance with FIPA proposals. It uses the Jabber protocol as a new message transport protocol (MTP). This protocol provides additional services that are not included in the current standard FIPA MTP. It provides facilities for “presence notification”, “multi-user conference” and “security services“. As a result of this work, a new plug-in for the JADE platform that incorporates this transport protocol has been developed.

Process mining and multi-agent models are powerful techniques for the analysis of processes and organizations. However, the integration of both fields has seldom been considered due to the lack of common conceptual background. We propose to close this gap by using Petri nets as an operational semantics and consider process mining a useful addition to monitor and debug multi-agent systems in the development phase. Mining results can be represented in the formalized form of Petri nets that allows to validate or verify the actual behavior.

On our way to mining complex interactions within (simulated) organizations, we present a plug-in extension of our Petri nets-based agent platform / for recording interaction logs. Using process mining, the logs can be mapped by some intermediate steps to agent protocols e.g. represented as AgentUML interaction protocol diagrams. These diagrams are a descriptive representation form that combines organizational and control flow information. Furthermore, they can be mapped to executable Petri nets, thus allowing to feed mining results back into the design phase.

This paper presents the rationale behind DIALOG: a formal framework for interaction protocol (IP) modeling that considers all the stages of a protocol engineering process, i.e. the design, specification, validation, implementation and management of IPs. DIALOG is organized into three views. The allows visual IP design. The automatically outputs, from the design, the syntactic specification of the IPs in a declarative-type language called ACSL. This improves IP publication, localization and communication on the Web, as well as IP machine learning by agents. Finally, the provides a formal (SOS) for the ACSL language. The paper focuses on the developed SOS, and shows how this semantics allows protocol property verification and eases automatic rule-based code generation from an ACSL specification for the purpose of simulating IP code execution at design time, as well as improving and assuring correct IP compliance at run time.

This paper presents an for task scheduling in a grid. Resource allocation is performed by an in which try to acquire their desired resource allocation profiles. To achieve an efficient bidding process, the auctioneer provides the bidding agents with approximated shadow prices from a linear programming formulation. The objective of this paper is to identify optimal bidding strategies in multi-agent settings with respect to varying preferences in terms of resource quantity and waiting time until bid acceptance. On the basis of a utility function we characterize two types of agents: a with a low preference for fast bid acceptance and an with a high valuation of fast allocation of the requested resources. Bidding strategies with varying initial bid pricing and different price increments are evaluated. Quantity maximizing agents should submit initial bids with low and slowly increasing prices, whereas impatient agents should start slightly below market prices and avoid ‘overbidding’.

Software systems that are intended to work autonomously in complex, dynamic environments should undergo extensive testing. Model-based testing advocates the use of purpose-driven abstractions for designing appropriate tests. The type of the software, the objective of testing, and the stage of the development process influence the suitability of tests. Simulation techniques based on formal modeling concepts can make these abstractions explicit and operational. A simulation model is presented that facilitates testing of autonomous software within dynamic environments in a flexible manner. The approach is illustrated based on the application Autominder.

Econometrics is nowadays an established approach to the discrete choice problem relying on statistical methods. It is used in several fields, e.g. route choice modelling, telecommunication analysis, etc. Despite its advantages, there are also some drawbacks. Thus, alternatives for modelling human choice are sought, which can reproduce overall system behavior and be valid at microscopic level.

In this paper, we propose an agent-based approach inspired in econometric techniques producing similar results on the macro level from microscopic behavior. This work aims to be a step forward on searching an alternative for econometrics.

An agent based simulator for evaluating operational policies in the transshipment of containers in a container terminal is described. The simulation tool, called SimPort, is a decentralized approach to simulating managers and entities in a container terminal. We use real data from a container terminal, for evaluating eight transshipment policies. The simulation results indicate that good choices of yard stacking and berthing position polices can lead to faster ship turn-around times, for instance, the Overall Time Shortening policy offers a lower cost and when combined with a Shortest Job First sequencing of arriving ships on average yielded a faster ship turn around time. The results also indicated, with respect to the studied performance measures that Stacking by Destination is a good choice of policy.

Diagnosis of plan failures is an important subject in both single- and multi-agent planning. Plan diagnosis can be used to deal with plan failures in three ways: () it provides information necessary for the adjustment of the current plan or for the development of a new plan, () it can be used to point out which equipment and/or agents should be repaired or adjusted so they will not further harm the plan execution, and () it can identify the agents responsible for plan-execution failures.

We introduce two general types of plan diagnosis: identifying the incorrect or failed execution of actions, and that identifies the underlying causes of the faulty actions. Furthermore, three special cases of secondary plan diagnosis are distinguished, namely , and .

In multi-agent planning problems agents are requested to jointly solve a complex task consisting of a set of interrelated tasks. Since none of the agents is capable to solve the whole task on its own, usually each of them is assigned to a subset of tasks. If agents are dependent upon each other via interrelated tasks they are assigned to, moderately coupled teams of agents are called for. Such teams solve the task by coordinating during or after planning and revising their plans if necessary. In this paper we show that such complex tasks also can be solved by loosely coupled teams of agents that are able to plan independently, although the computational complexity of the coordination problems involved is high. We also investigate some of the factors influencing this complexity.

Business process management has been identified as an interesting application area for agent technologies. Current developments in Web technologies support the execution of business processes in a networked environment. In this context, the flexible composition and usage of services in a service-oriented environment is a key feature. Additionally, the model-driven architecture (MDA) idea of transforming models on different abstraction levels, from highly abstract design-oriented views to an executable program, is a current trend in business process modeling. BDI agents provide a framework for both aspects by employing a planning from second principles approach, which uses a predefined library of plans and instantiates and adapts these plans. From this perspective, plans are design-time models for agent task execution and for Web Service composition. This paper presents a Rapid Prototyping framework for SOAs built around a Model-Driven Development methodology which we use for transforming high-level specifications of an SOA into executable artefacts, both for Web Services (WSDL files) and for BDI agents. The framework was designed to handle a mix of new and existing services and provides facilities for simulating, logging, analysing and debugging. Our framework was validated on a real industrial electronic procurement scenario in the furniture manufacturing industry. Once input from business experts had been collected, creating the high-level PIM4SOA (Platform Independent Model for SOA) model, deriving the Web service description and incorporating existing Web services took less than a day for a person already familiar with the techniques and tools involved. We show that rapid prototyping of SOAs is possible without sacrificing the alignment of the prototype with high-level architectural constraints.