Agent Technology This file is under construction.
Abstract
The research reported in this paper has both a scientific and a
commercial aim. The scientific interest is to explore the use of
contexts in order to improve the quality of information brokering. In
this paper it is shown that contexts in information brokering can be
exploited to enable four directions of query reformulation: up and
down (standard query expansion) and sideway reformulations of the user
request that can even involve going from one context to another.
Abstract
In this paper an executable generic process model is proposed for
combined verbal and non-verbal communication processes and their
interaction. The agent-based architecture can be used to create multi-modal
interaction. The generic process model has been designed, implemented
interactively and used to simulate different types of interaction
between verbal and non-verbal communication processes: a non-verbal
communication process can add and modify content to a verbal
communication process, but can also provide a protocol for the
(control of the) verbal communication process. With respect to the
communication protocol both stimulus-response behaviour and
deliberative behaviour have been modelled and simulated. The semantics of
the model has been formalised by threelevelled partial temporal models,
covering both the material and mental processes and their relations.
Abstract
This paper presents an architecture for an agent capable of
deliberation about the creation of new agents, and of actually
creating a new agent in the multi-agent system, on the basis of this
deliberation. The agent architecture is based on an existing generic
agent model, and includes explicit formal conceptual representations
of both design structures of agents and (behavioural) properties of
agents that can be used as requirements. The process of deliberation
is modelled as a design process, based on an existing generic design
model. To actually create a new agent at run-time on the basis of the
design results, the agent executes a creation action in the material
world, which leads to a world state update to include the new agent,
after which the new agent functions within the multi-agent system.
This approach enables the design of evolution processes in societies
of agents for which the evolution is not a merely material process
which takes place in isolation from the mental worlds of the agents,
but allows for interaction between mental and material processes. A
combined mind-matter approach results in which the agents in a society
can deliberatively influence the direction of the evolution,
comparable to the potential offered by genetic engineering. The
architecture has been designed using the compositional development
method DESIRE, and has been tested in a prototype implementation.
Abstract
In this paper an agent-based electronic market architecture is described. The architecture has been designed in a compositional manner using elements of agent technology and knowledge technology. It is shown how a combination of generic agent models, ontologies and knowledge provides an adequate approach to address the dynamic, distributed and knowledge-intensive character of the application.
Abstract
A generic model for the internal dynamic behaviour of BDI agents is
proposed. This model, a refinement of a generic agent model, explicitly
specifies beliefs and motivational attitudes such as desires, goals, intentions,
commitments, and plans, and their relations. A formal meta-language is used
to represent beliefs, motivational attitudes and strategies. Dynamic aspects of
reasoning about and revision of beliefs and motivational attitudes are modelled
in a compositional manner using the multi-agent system development method DESIRE.
Abstract
This paper introduces a compositional design of a generic agent model at a conceptual and logical level. This generic agent model abstracts from specific application domains; it can be (re)used for a large variety of agent types and application domains. The model was designed on the basis of experiences in a number of application domains. The principled compositional development method DESIRE was used to design this agent model. To illustrate reuse of this agent model, co-operative information gathering agents are modelled.
Abstract
This paper presents an architecture for an agent capable of deliberation about the creation of new agents, and of actually creating a new agent in the multi-agent system, on the basis of this deliberation. After its creation the new agent participates fully in the running multi-agent system. The agent architecture is based on an existing generic agent model, and includes explicit formal conceptual representations of both structures of agents and (behavioural) properties of agents that can be used as requirements. Moreover, to support the deliberation process the agent has explicit knowledge of refinement relations between properties and knowledge of relations between structure and properties of agents. To actually create a new agent at run-time on the basis of the results of deliberation, the agent executes a creation action in the material world, which leads to a world state update to include the new agent, after which the new agent functions within the multi-agent system. This approach enables the design of evolution processes in societies of agents for which the evolution is not a merely material process which takes place in isolation from the mental worlds of the agents, but allows for interaction between mental and material processes. A combined mind-matter approach results in which the agents in a society can deliberatively influence the direction of the evolution, comparable to the potential offered by genetic engineering. The architecture has been designed using the compositional development method DESIRE, and has been tested in a prototype implementation.
Abstract
In this paper three different roles of a shared task model as an intermediate representation of a task are presented and illustrated by applications developed in cooperation with industry. First the role of a shared task model in knowledge acquisition is discussed. In one of the two applications, decision support in the domain of soil sanitation, one of the existing generic task models for diagnostic reasoning provided a means to structure knowledge acquisition. In the second application, diagnosis of chemical processes, the acquisition process resulted in a shared task model for diagnostic reasoning on Nylon-6 production. Secondly, the role of a shared task model in designing user interaction is addressed. Three levels of interaction are considered of importance: interaction at the object level, at the level of strategic preferences, and at the level of task modification. In an application in the domain of environmental decision making, this led to the design of a user interface based on the acquired shared task model, within which all three levels of interaction were available to users. Finally, the role of shared task models within a multi-agent system including a clarification agent is addressed. Two software agents were designed that each share a task model with the user: one for a diagnosis task, and one for a clarification task. The shared model of the clarification task reflects the shared task model of diagnosis; clarification includes clarification of the overall diagnostic reasoning process. The multi-agent architecture presented has been developed to support a user both at the level of the diagnostic task he or she is performing and at the level of clarification. The architecture has been applied to diagnosis of chemical processes.
Abstract
This paper addresses management of conflicts in an agent by means
of reflective reasoning. A structure for reflective agents is proposed
within which reasoning about observation, assumption making and
communication; an agent's own information state and reasoning processes;
other agents' information states and reasoning processes, and combinations
of these types of reflective reasoning are explicitly modelled. The types
of knowledge needed to detect, analyse and resolve conflicts that arise by
meta-reasoning within the agent are discussed. The knowledge and
interaction between agents required to model the wise men's puzzle is used to
illustrate the approach.
Abstract
In this paper a compositional model for reflective agents is proposed within which reasoning about observation, assumption making and communication; an agent's own information state and reasoning processes; other agents' information states and reasoning processes, and combinations of these types of reflective reasoning are explicitly modelled. The types of knowledge needed to detect, analyse and resolve conflicts that arise by meta-reasoning within the agent are discussed. The knowledge and interaction between agents required to model the wise men's puzzle is used to illustrate the approach. The model has been validated using think-aloud protocols. An implementation has been made including a speech synthesis facility.
Abstract
In this paper norms are assumed to be useful in agent societies, but it is also claimed that the possibility of 'intelligent' norm violation can be useful. Principles for agents that are able to behave deliberately on the basis of explicitly represented norms are identified and an architecture is introduced. Using this agent architecture, norms can be communicated, adopted and used as meta-goals on the agent's own processes. As such they have impact on deliberation about goal generation, goal selection, plan generation and plan selection. The architecture is operational within the distributed DESIRE software environment.
Abstract
When a compositional multi-agent system is to be verified, it is natural to do
this compositionally. In this paper we explore the use of a temporal epistemic
logic to formalize specification, properties, and their proofs, of compositional
multi-agent systems. The specification of the system, its properties and their
proofs are of a compositional nature. It is shown that compositional proofs
are valid under certain restrictions. Finally, the possibility of incorporating
default persistence of information in a system into a temporal specification, is
explored.
Abstract
In this paper it is shown how informal and formal specification of behavioural requirements and scenarios for agents and multi-agent systems can be integrated within multi-agent system design. In particular, it is addressed how a compositional perspective both on design descriptions and specification of behavioural requirements can be exploited. The approach has been applied in a case study: the development of a mediating information agent. It is shown that compositional verification benefits from the integration of requirements engineering within the design process.
Abstract
In this paper a multi-agent architecture for intelligent Websites is presented and applied in insurance. The architecture has been designed and implemented using the compositional development method for multi-agent systems DESIRE. The agents within this architecture are based on a generic broker agent model. It is shown how it can be exploited to design an intelligent Website for insurance, developed in co-operation with the software company Ordina Utopics and an insurance company.
Abstract
The generic agent architecture described can be instantiated by adding specific types of knowledge to support functionalities and behaviour required. Depending on the choice of these requirements, an agent is created for a specific context by including the appropriate types of knowledge. The agent architecture supports its own modification due to the fact that basic functionalities are specified in an explicit declarative manner, in the form of knowledge. It is possible to dynamically modify the agent by adding or deleting some of its knowledge. Since this declaratively represented knowledge can be the subject of communication between agents, modification can be performed at a distance: another agent (e.g., a dedicated maintenance agent) communicates the knowledge needed for the modification to the agent that is to be modified.
Abstract
In this paper a generic information broker agent for intelligent Websites is introduced. The agent architecture has been designed using the compositional development method for multi-agent systems DESIRE. The use of the architecture is illustrated in an Electronic Commerce application for a department store.
Abstract
The aim of this paper is to analyse and formalise the dynamics of trust in the light of experiences. A formal framework is introduced for the analysis and specification of models for trust evolution and trust update. Different properties of these models are formally defined.
Abstract
In this paper an executable generic process model is proposed for combined
verbal and non-verbal communication processes and their interaction. The
model has been formalised by three-levelled partial temporal models,
covering both the material and mental processes and their relations. The
generic process model has been designed, implemented and used to simulate
different types of interaction between verbal and non-verbal communication
processes: a non-verbal communication process that adds and modifies
content to a verbal communication process, but also provides a protocol
for the (control of the) verbal communication process. With respect to the
communication protocol stimulus-response behaviour and deliberate behaviour
have been modelled and simulated.
Abstract
Emerging technologies allowing two-way communication between utility
companies and their customers, as well as with smart equipment, are
changing the rules of the energy market. Deregulation makes it even more
demanding for utility companies to create new business processes for mutual
benefit. Dynamic load management of the power grid is essential to make
better and more cost-effective use of electricity production capabilities, and to
increase customer satisfaction. The compositional development method
DESIRE has been used to analyse, design, implement and verify a multi-agent
system capable of negotiation for load management.
Abstract
A compositional verification method for multi-agent systems is presented and
applied to a multi-agent system for one-to-many negotiation in the domain of
load balancing of electricity use. Advantages of the method are that the
complexity of the verification process is managed by compositionality, and
that parts of the proofs can be reused in relation to reuse of components.
Abstract
This paper introduces a multi-agent system architecture to increase the value
of 24 hour a day call centre service. This system supports call centres in
making appointments with clients on the basis of knowledge of employees
and their schedules. Relevant activities of employees are scheduled for
employees in preparation of such appointments. The multi-agent system
architecture is based on principled design, using the compositional
development method for multi-agent systems DESIRE. To schedule
procedures in which more than one employee is involved, each employee is
represented by its own personal assistant agent, and a work manager agent
co-ordinates the schedules of the personal assistant agents, and clients
through the call centre. The multi-agent system architecture has been applied
to the banking domain, in co-operation with and partially funded by the
Rabobank.
Abstract
In many areas development methods have been developed in a conceptual
design of complex systems is specified before systems are implemented. Such
specifications focus on the semantics of systems abstracting from
implementation details, providing a basis for verification and validation of the
functionality of the systems. A dedicated development method for multi-agent
systems, requires adequate means to describe the characteristics of multi-agent
systems, in particular, the control of the dynamics of (concurrent) reasoning
behaviour and acting behaviour (e.g., guided reasoning, observation,
communication and execution of actions). A compositional multi-agent system
development method based on the principles described in this paper can
provide support to multi-agent system designers during the entire design
process: process and knowledge abstraction, compositionality, reuse,
semantics and formal analysis with respect to verification and validation. One
specific compositional multi-agent development method is DESIRE (DEsign
and Specification of Interacting REasoning components). Although the paper
addreses the principles of compositional multi-agent system development
from a generic perspective, some of the examples used to illustrate the notions
discussed are taken from this compositional development method.
Abstract
Abilities of agents and properties of their environment provide a means to
describe behaviour and functionality. These abilities also provide a basis for
re-design. In this paper an example is given of a prototype system for re-
design of a multi-agent system in which the abilities and properties are made
explicit.
Abstract
This paper presents a generic architecture for an agent capable of designing and creating new agents. The design agent itself is based on an existing generic agent model, and includes a refinement of a generic model for design, in which strategic reasoning and dynamic management of requirements are explicitly modelled. This model is refined for the design of agents, or (parts of) multi-agent systems. It includes an explicit formal representation at a logical level of (1) requirements that can be formulated for agents and multi-agent systems, and (2) design object descriptions of a (part of a) multi-agent system. The generic architecture has been formally specified in DESIRE, and has been tested in a prototype application.
Abstract
This paper presents a generic architecture for a design agent. The design agent is based on an existing generic agent model, and includes a refinement of a generic model for design, in which strategic reasoning and dynamic management of requirements are explicitly modelled. The generic architecture has been designed using the compositional development method DESIRE, and has been used to develop a prototype design agent for automated agent design.
Abstract
A compositional method is presented for the verification of multi-agent
systems. The advantages of the method are the well-structuredness of the
proofs and the reusability of parts of these proofs in relation to reuse of
components. The method is illustrated for an example multi-agent system,
consisting of co-operative information gathering agents. This application of
the verification method results in a formal analysis of pro-activeness and
reactiveness of agents.
Abstract
To support users on the World Wide Web, various types of agents can be,
and actually have been, developed. For example, to support brokering
processes in electronic commerce, personal assistant agents can be developed
that support a user offering products (or services) at the Web, or agents that
support search for information on products within a user's scope of interest,
or agents that combine both types of functionalities. Moreover, mediating
agents can be developed that communicate both with personal assistant agents
that provide information on products and with personal assistants that ask for
information on products. Recently a few applications of broker agents have
been addressed for this area. In general, applications like these are
implemented in an ad hoc fashion without an explicit design at a conceptual
level. This paper briefly describes a generic agent architecture for agents
acting in brokering processes that has been designed in a principled,
compositional manner using the compositional development method for multi-
agent systems DESIRE. This agent architecture can be instantiated by adding
specific types of knowledge to support functionalities and behaviour required.
Depending on the choice of these requirements, an agent is created for a
specific context by including the appropriate types of knowledge.
Abstract
In this paper it is shown how animal behaviour can be simulated in an agent-
based manner. Different models are shown for different types of behaviour,
varying from purely reactive behaviour to pro-active and social behaviour.
The compositional development method for multi-agent systems DESIRE and
its software environment supports the conceptual and detailed design, and
execution of these models. Experiments reported in the literature on animal
behaviour have been simulated for a number of agent models.
Abstract
A generic broker agent architecture is introduced, designed in a principled
manner using the compositional development method for multi-agent systems
DESIRE. A flexible, easily adaptable agent architecture results in which, in
addition, facilities have been integrated that provide automated support of the
agent's own maintenance. Therefore, the agent is not only easily adaptable,
but it shows adaptive behaviour to meet new requirements, either in reaction
to communication with a maintenance agent, or in a fully autonomous
manner. Based on this architecture, applications are being developed in
Electronic Commerce, in co-operation with the Internet application company
Crisp, and in intelligent Web-sites, in co-operation with the insurance
company Delta Lloyd and the software company Ordina Utopics.
Abstract
In this paper a reusable multi-agent architecture is presented for reasoning
tasks that are supported by a system that interacts with the user at two levels:
at the level of the reasoning process itself and at the level of clarification of the
process. The multi-agent architecture distmguishes three agents: a user, a
decision support agent and a clarification support agent. The user and the
decision support agent cooperate on the basis of a shared model of the
reasoning task; the user and the clarification support agent cooperate on the
basis of a shared model of the clarification task. Interaction between the user
and the decision support agent, between the user and the clarification support
agent, and between the decision support agent and the clarification agent are
made explicit in the model. The model has been made using the compositional
modelling framework DESIRE. In cooperation with and funded by chemical
industry, it has been applied to diagnosis of chemical processes.
Abstract
In this paper compositional verification of agents in dynamic environments is studied.
Dynamic properties of an example agent in a dynamic environment are identified in
relation to the different abstraction levels of the compositional structure of the system.
The properties are formalised using temporal models. Mathematical proofs relate the
properties at the different process abstraction levels. The dynamics of the environment
has several consequences for the verification process. Properties often have to contain conditions concerning the dynamic behaviour of the world. In the proofs, the partly
unpredictable behaviour of the word has to be taken into account. This complicates
the verification process. A number of aspects of proof pragmatics (i.e., heuristics
for finding proofs) identified during this analysis and aimed at controlling the proof
complexity, are discussed.
Abstract
In this paper a semantic model is proposed for combined verbal and non-verbal communication processes and their interaction. The semantic model has been formalised by three-levelled partial temporal models, covering both the material and mental processes and their relations. Moreover, an executable generic process model has been designed and used to simulate different types of interaction between verbal and non-verbal communication processes: a non-verbal communication process that adds and modifies content to a verbal communication process, but also provides a protocol for the (control of the) verbal communication process. With respect to the communication protocol stimulus-response behaviour and deliberate behaviour have been modelled.
Abstract
In spite of the rapid spread of agent technology, there is, as yet, little evidence
of an engineering approach to the development of multi-agent systems. For
example, both development methods and verification methods for multi-agent
systems are rare. In this paper, we describe a case study aimed at comparing
two formal agent languages, namely Concurrent METATEM and DESIRE. A
version of the well known PRS architecture is developed and the approaches
are compared with respect to this application.
Abstract
This paper discusses an example of the application of a high-level modelling
framework which supports both the specification and implementation of a
system's conceptual design. This framework, DESIRE (framework for
DEsign and Specification of Interacting REasoning components), explicitly
models the knowledge, interaction, and coordination of complex tasks and
reasoning capabilities in agent systems. For the application domain addressed
in this paper, an operational multi-agent system which manages an electricity
transportation network for a Spanish electricity utility, a comprehensible
specification is presented.
Abstract
Much research concerning the design of multi-agent systems (at a conceptual
level) addresses complex agents which exhibit complex interaction patterns.
Due to this complexity, it is difficult to perform rigorous experimentation. On
the other hand, systematic experimental work regarding behaviour of societies
of more simple agents, while reporting valuable results, often lacks
conceptual specification of the system under consideration. In this paper, the
compositional multi-agent development method DESIRE is not only
successfully used to develop a conceptual specification of simple agents that
together form a society, but also to simulate the behaviour in a dynamic
environment. In DESIRE, a conceptual specification, which provides a high-
level view of an agent, has enough detail for automatic prototype generation.
The prototype implementation of the conceptual specification of the simple
agents has been used to replicate and extend one of the experiments reported
in the literature.
Abstract
Interaction between distributed information systems can be modelled as
interaction between autonomous agents. The compositional development
method DESIRE is used to design and specify a multi-agent model for
competitive interaction, such as the interaction required to access limited
resources. A reusable generic model for a competitive agent is presented
together with a model of interaction between such agents.
Abstract
A cooperation model based on joint intentions introduced by Jennings is
formalised within the modelling framework DESIRE for compositional multi-
agent systems. By formalising the model in DESIRE, operationalisation and
reusability of the model are obtained, as DESIRE specifications are executable
and easily reusable.
Abstract
In agent models often it is assumed that the agent maintains internal
representations of the material world (e.g., its beliefs). An overall model of
the agent and the material world necessarily incorporates sub-models for
physical simulation and symbolic simulation, and a formalisation of the (static
and dynamic) representation relation between the two types of sub-models. If
it is also taken into account that the agent's mind has a materialisation in the
form of a brain, the relations between mind and matter become more complex.
The question of how the different types of interaction between mind and
matter of an agent and the material world can be modelled in a semantically
sound manner is the main topic of this paper. The model can be used to
simulate a variety of phenomena in which (multiple) mind-matter interactions
occur, such as sensing, acting, (planned) birth and death, causing brain
damage, and psychosomatic diseases.
Abstract
A formal approach to the design of (meta-level) compositional architectures
for multi-agents systems is presented. A structure for reflective agents is
proposed within which reasoning about observation and communication, an
agent's own information state and reasoning processes, other agents'
information states and reasoning processes, and combinations of these types
of reflective reasoning are explicitly modelled. To illustrate the approach the
wise men's puzzle has been modelled using different types of reflection.
Abstract
A declarative compositional modelling framework, DESIRE, designed to
model knowledge-intensive multi-agent systems, is shown to provide a means
to model distributed industrial and business processes. An agent's
knowledge, reasoning processes and interaction with other agents, and the
world are explicitly specified within this framework. Electricity transportation
management is used to illustrate the characteristic elements of the approach, in
particular with respect to dynamic aspects of distributed industrial and
business processes; aspects which are of importance to knowledge
management and knowledge engineering.
Abstract
In current engineering practice often traditional management structures and
virtual organisations are combined. In addition to formal structures, informal,
dynamic organisational structures emerge in which engineers are personally
responsible for effective interaction. They decide when to exchange
information, and with whom, when to question requirements, when to
acknowledge conflicts, et cetera. In such virtual organisations, project
coordination may become quite complicated. In this paper communication and
coordination in a real-life case of concurrent design in aircraft industry has
been modelled and specified within the modelling framework DESIRE, on the
basis of Jennings informal, multi-agent model of cooperative problem solving
known in the literature.
Abstract
In this paper the modelling framework DESIRE, originally designed for
formal specification of complex reasoning systems is used to specify a real-
world multi-agent application on a conceptual level. Some extensions to
DESIRE are introduced to obtain a useful formal specification framework for
multi-agent systems.
Abstract
In this paper it is investigated how multi-agent systems with complex agents
can be designed and formally specified based on the notion of a compositional
architecture. After identifying the types of knowledge required for an agent
we formally define a multi-agent system. Moreover, a specific type of agent
with various capabilities of reasoning and acting is given. Some essential
patterns of integrated reasoning, communication and interaction with the
material world are described. Finally, we present an overview of formal
semantics for our approach.
Abstract
This paper addresses the issue of the use of formal modelling languages in
multi-agent domains. As a main question we evaluate in what respect the
formal modelling language DESIRE fulfills the requirements imposed by
these domains. To get an answer we studied two examples of multi-agent
tasks and developed formal specifications in DESIRE of large parts of these
examples. Our results are encouraging: it is quite feasible to extend the
applicability of the formal modelling language DESIRE to multi-agent
domains. Especially for the case of more complex agents the possibility to use
such a compositional formal modelling language may be valuable: not only to
model the agents themselves, but also the interactions between agents in a
conceptual and formal manner.