Michel A. Oey

A proposal for WS-Agreement Negotiation

The Web Services Agreement specification defines a normative language to formulate Service Level Agreements and a basic protocol to expose service-level descriptions, validate service-level requests, and come to an agreement. This protocol, often called “take-it-or-leave-it”, allows a service provider and a service consumer to decide whether to accept or reject a service offer. Although this approach is sufficient for a number of use cases, others exist with requirements for multi-step negotiation or the adaptation of an existing agreement. In this paper, we describe the Web Services Agreement Negotiation protocol, a proposal by the Open Grid Forum to extend the existing specification. This proposal is the result of combining various research activities that have been conducted to define protocols for negotiating service levels or to supersede the existing “take-it-or-leave-it” protocol. The main characteristics of this proposal are the multi-round negotiation capability, renegotiation capability, and compliance with the original specification.

Enforcing security in the AgentScape middleware

Multi Agent Systems (MAS) provide a useful paradigm for accessing distributed resources in an autonomic and self-directed manner. Resources, such as web services, are increasingly becoming available in large distributed environments. Currently, numerous multi agent systems are available. However, for the multi agent paradigm to become a genuine mainstream success certain key features need to be addressed: the foremost being security. While security has been a focus of the MAS community, configuring and managing such multi agent systems typically remains non-trivial. Well defined and easily configurable security policies address this issue. A security architecture that is both flexible and featureful is prerequisite for a MAS. A novel security policy enforcement system for multi agent middleware systems is introduced. The system facilitates a set of good default configurations but also allows extensive scope for users to develop customised policies to suit their individual needs. An agent middleware, AgentScape, is used to illustrate the system.

Enforcing integrity of agent migration paths by distribution of trust

Agent mobility is the ability of an agent to migrate from one location to another across a network. Though conceptually relatively straightforward, in practice security of mobile agents is a challenge: from transport layer security to preservation of integrity in open environments. This paper discusses the security issues involved and proposes protocols for secure agent migration. AgentScape, an agent platform for mobile agents, is used to illustrate the feasibility of the implementation of these protocols.

Agent-based information infrastructure for disaster management

The success of a disaster management process depends on effective, secure and efficient information flow. This paper proposes an agent-based distributed information infrastructure to enable the realization of such secure information flows in disasters. The proposed infrastructure uses software agents in the exchange and processing of information, secure and dynamic information sharing and automated information flow generation and configuration.

A Framework for Developing Agent-Based Distributed Applications

The development of large-scale distributed multi-agent systems in open dynamic environments is a challenge. System behavior is often not predictable and can only be evaluated by execution. This paper proposes a framework to support design and development of such systems: a framework in which both simulation and emulation play an important role. A distributed agent platform (AgentScape) is used to illustrate the potential of the framework.The development of large-scale distributed multi-agent systems in open dynamic environments is a challenge. System behavior is often not predictable and can only be evaluated by execution. This paper proposes a framework to support design and development of such systems: a framework in which both simulation and emulation play an important role. A distributed agent platform (AgentScape) is used to illustrate the potential of the framework.

Design of a Secure and Decentralized Location Service for Agent Platforms

Agent platforms designed for Internet-scale, open networks need scalable and secure location services for agents and services. The location service based on the Fonkey public key distribution infrastructure presented in this paper has been designed and implemented for this purpose. It is scalable in the total number of published identifier---contact address pairs, the number of updates/changes, and the number of agent platforms publishing and requesting contact addresses. This system also supports a signing mechanism to authenticate the publisher of an identifier---contact address pair. Experimental results show that the current implementation based on the Bunshin/Free Pastry overlay network exhibits good scaling behavior.

Symphony – Agent-Based Platform for Distributed Smart Grid Experiments

The electricity networks in many countries are facing a number of challenges due to growth in peak demand, integration of renewable energy sources, increasing security risks and environmental concerns. Smart Grid, as an automated and widely distributed energy network, offers viable solutions to those challenges. Software agents running on customer premises or embedded in appliances and equipment can be used to plan future energy consumption and to shift loads according to pre-defined constraints. However, testing such distributed solutions prior to actual deployment in domestic households is a challenge. Simulations may not capture all the aspects of distributed, large-scale, complex environments, such as one can find in the Smart Grid. This paper presents a distributed Smart Grid simulation/emulation environment called Symphony that allows running real-world experiments within distributed environment with the participation of multiple actors. Symphony is being developed in the context of a European Institute for Innovation and Technology project.

Modelling Multi-stakeholder Systems: A Case Study

A contemporary governance challenge for governments concerns the biogas domain: what incentives and policies can lead to a viable biogas economy? To support addressing this challenge, a prototype of a simulator is constructed in which horizontal governance is applied in a multi-stakeholder context. This paper reports on the modelling and knowledge acquisition that led to the development of that prototype. Rather than (re)inventing tooling, three available agent-based modelling approaches are combined: the MAIA meta-model, OperA and GENIUS, with Agents cape as the agent-based middleware for the realisation of the simulator. The resulting simulator has been validated by biogas experts from Alliander (NL-based energy network company), leading to confirmation that our combined approach was useful for the analysis of this multi-stakeholder domain.

WS-agreement based resource negotiation in AgentScape

Mobile agents require access to computing resources on heterogeneous systems across the Internet. This demo illustrates how agents can negotiate terms and conditions of resource access with one or more mediators representing virtual organizations of autonomous hosts, before migrating to a new location. Time-limited resource contracts are the result: contracts between agents and mediators, and contracts between mediators and hosts. The negotiation protocol and language are based on the WS-Agreement Specification, and have been implemented and tested within the Agent-Scape framework. The demonstration shows in detail how this negotiation framework has been implemented for resource access on remote, distributed systems.

Dynamic Data-Driven Experiments in the Smart Grid Domain with a Multi-agent Platform

Pervasive information and communication technologies and large-scale complex systems, are strongly influencing todays networked society. Understanding the behaviour and impact of such distributed, often emergent systems on society is of vital importance. This paper proposes a new approach to better understand the complexity of large-scale participatory systems in the context of smart grids. Multi-agent based distributed simulations of realistic multi-actor scenarios incorporating real-time dynamic data and active participation of actors is the means to this purpose. The Symphony experiment platform, developed to study complex emergent behaviours and to facilitate the analysis of the system dynamics and actor interactions, is the enabler.