Afsaneh Haddadi

Application of multi-agent systems in traffic and transportation

Agent-oriented techniques offer a new approach to support the whole software development process. All the phases in the software development process are treated with a single uniform concept, namely that of agents, and a system modelled by a collection of agents is called a multi-agent system. AOTs as a new advance in information technology can help to respond to the growing interest in making traffic and transportation more efficient, resource-saving and ecological. The authors give an overview of a diverse range of applications where multi-agent systems promise to create a great impact in this domain. To demonstrate the ideas behind AOTs and their applicability in this domain, two applications under development at Daimler-Benz Research are described in some detail.

Generic, configurable, cooperation protocols for multi-agent systems

In this paper we propose a unified and general mechanism for developing cooperation protocols in multi-agent systems. The protocols are essentially speech act based but have considerable advantages as compared to previous approaches: First, they are generic in the sense that a protocol execution algorithm can treat the domain independent parts separately from the application dependent reasoning and deciding processes involved. And second, they are recursively defined from primitives which allow a designer (or eventually the agents themselves) configure the appropriate general or domain-specific cooperation protocols.

An Adaptive Conversational Interface for Destination Advice

In this paper, we describe the Adaptive Place Advisor, a conversational interface designed to help users decide on a destination. We view the selection of destinations as an interactive process of constraint satisfaction, with the advisory system proposing attributes and the human responding. We further characterize this task in terms of heuristic search, which leads us to consider the systems representation of problem states, the operators it uses to generate those states, and the heuristics it invokes to select these operators. In addition, we report a graphical interface that supports this process for the specific task of recommending restaurants, as well as two methods for constructing user models from interaction traces. We contrast our approach to recommendation systems with the more common scheme of showing users a ranked list of items, but we also discuss related work on conversational systems. In closing, we present our plans to evaluate the Adaptive Place Advisor experimentally and to extend its functionality.

On Abstract Models and Conversation Policies

It is possible to define conversation policies, such as communication or dialogue protocols, that are based strictly on what messages and, respectively, what performatives may follow each other. While such an approach has many practical applications, such protocols support only “local coherence” in a conversation. In a mixed-initiative dialogue between two agents cooperating on some joint task, there must be a “global coherence” in both the conversation and in the task they are trying to accomplish. Recognition of agent intentions about the joint task is essential for this global coherence, but there are further mechanisms needed to ensure that both local and global coherence are jointly maintained. This paper presents a general yet practical approach to designing, managing, and engineering agents that can engage in mixed-initiative dialogues. In this approach, we promote developing abstract task models and designing conversation policies in terms of such models.

Agent-oriented techniques for traffic and manufacturing applications: progress report

We view agent-oriented techniques (AOT) as a further development of techniques in object-oriented systems and distributed systems. AOT extend object-oriented techniques in that the analysis, design, and realization of complex systems are performed on a higher level of abstraction, and in that agents are active, concurrent objects, collectively embedded in a ‘society.’ Furthermore, agents are a specialization of objects in that the internal states of objects are typed by intentional states, for example, and in that messages exchanged among agents are classified by message types (Shoham, 1993). AOT can lean upon techniques provided by distributed systems (like sharing resources and synchronization), but they complement these techniques by making subsystems more autonomous and enabling them to co-ordinate their activities actively instead of being co-ordinated by design.

Abstract task specifications for conversation policies

Task Specifications for Conversation Policies

Making it up as they go along: A theory of reactive cooperation

In this article, we present a formal theory of on-the-fly cooperation. This is a new model of joint action, which allows for the possibility that a group of cooperating agents will, in general, have neither the information nor the time available to compute an entire joint plan before beginning to work. It proposes that cooperating agents need therefore only reason about what to do next; what represents a believable next action. Thus, agents literally make it up as they go along: a plan only unfolds as cooperation continues. A detailed rationale is presented for the new model, and the components of the model are discussed at length. The article includes a summary of the logic used to formalise the new model, and some remarks on refinements and future research issues.

Communication among Rational Agents

In this article we identify and give the formal semantics of a set of generic speech acts that can be performed by agents in communicating about a potential cooperation, and demonstrate how agents may reason about when, with whom, and what to communicate in this process. The aim of this exercise is to highlight various facets of study on communication and the diversity of issues to be considered in designing agents that can intelligently, flexibly and most of all, effectively communicate with one another. This is particularly important for the design and development of standards and protocols for communication among heterogeneous agents that often share little or no commonality in their internal design. As is a tradition in AI, a thorough theory of communication in multi-agent systems takes its input from a diverse range of disciplines and this article attempts to integrate some of the more important, seemingly separate viewpoints, into a unified study of communication among rational agents.