| | | D.1.3 NIAD&R: Plan for 2004 |
D.1.3 NIAD&R: Plan for 2004
NIAD&R (Distributed Artificial Intelligence & Robotics Group) is
LIACC's group
belonging to the Faculty of Engineering at the University of Porto.
Our team includes
4 PhD (one Senior), 7 Researchers (including PhD students), 6 other
MSc's students
and three external collaborators. NIAD&R is the smallest LIACC's
group and is mostly
devoted to the Research in Distributed Artificial Intelligence and
Agent-based
Systems. More precisely, both the theoretical and practical aspects of
Autonomous
Agents as well as Multi-Agent Systems have been the broad areas of
interest for our
research. Our main research motivation relies on improving models for
agent-based systems
interoperability and applications.
We can further identify specific topics inside these areas as shown
below:
(i) Automatic Negotiation Models for Autonomous Agents, (ii) Agents'
Adaptation,
Learning and Emotions; (iii) Multi-Agent teams's coordination; (iv)
Multi-agent
Systems applications.
In the following sub-sections a more detailed description of the work
we intend to pursue
is presented.
People involved: Eugénio Oliveira, Ana Paula Rocha, Henrique
L. Cardoso, Luís Nogueira, Andreia Malucelli
Coordinator: Eugénio Oliveira
Research direction: Research in the context of this issue aims at
developing
an Electronic Institution for safe and trustable agent-based business
operations.
This includes appropriate models for both B2B and B2C Negotiation
processes as well
as to provide platforms, tools and frameworks enabling Agents'
interaction in the
context of Virtual Enterprise formation and operation processes.
Models and Protocols for Autonomous Agents' Negotiation
Research goals: To develop, implement and test models for
autonomous,
individually rational, agents representing either individuals or
enterprises
willing to reach fair agreements through flexible negotiation.
- To enhance previously developed Q-Negotiation algorithm.
- To develop further and test a specific tool we have been
developing for B2B interaction.
- To test a specif tool for E-Brokering in the Insurance Domain.
RECENT WORK (2003):
- As a result of several meetings of AMEC (Agent Mediated
Electronic Commerce) SIG
of the AgentLink European Network of Excellence, the concept of
Electronic Institution
has emerged. In order to develop and implement this concept, i.e. a
framework enabling secure and responsible (enterprises' delegates)
agents'interaction
we have now a first implemention of ForEV (Virtual Enterprises
Formation framework).
Besides all the facilities for registration and matching between
mutually interested
agents, ForEV already provides sophisticated negotiation protocols
with learning
capabilities - Q-Negotiation Algotithm.
Q-Negotiation, developed in 2002 by Ana Paula Rocha and Eugénio
Oliveira (referred in
the 2002 report) is an advanced negotiation protocol for
agents in the context of the Virtual Enterprise Formation stage,
that encompasses the following characteristics:
- multi-issue evaluation function relying on the several
different agents
individual preferences;
- qualitative feedback during negotiation, enabling the agents
keeping
their own preferences private;
- continuous adaptation to the dynamics of the market by using a
slightly modified reinforcement learning algorithm to find out the new
current bid to submit to the market;
- Apropriate procedures for solving simple distributed constraints
among items
under negotiation, making the all process to converge to the mutually
accepted
solutions space.
A Java-based implementation including several layers of the JATLite
platform (including
some modified classes for multiple-routers) is now ready for
experimentation on different domains of
application.
- Moreover we have implemented and tested [Nog03a], [Nog03b], [Nog03c], a new model
for automatic agent-based E-brokering in the important domain of
insurance products.
The implemented model encompasses different kinds of negotiation
protocols between both the
Broker agent and the Insurance companies agents as well as between the
Broker agent and the
personalised Customer agents. The main idea is to intelligently
mediate by supplying Customers with
meaningful information gathered from the available Insurance products.
Also, by taking advantage of previously
inferred customer preferences the Broker is able to negotiate
different, although relevant offers
and rank them for the customer. The Broker Agent is then able to
incrementally
build up different and separate Customers groups and associate to them
meaningful (and useful)
stereotypes. Special non-supervised learning algorithms are used. The
final prototype has
been developed on the top of a very flexible tool called Bee-Gent
(from Toshiba).
- We came to the conclusion that, in order to enable flexible
interaction between
heterogeneous agents, a set of services based on ontologies should be
provided.
After a systematic study on Ontologies that has been done in the
framework of a PhD thesis
preparation (A.Malucelli), a first description about what these
Ontology-services can be,
has already been provided [Malu03]. We are also designing a
specific scenario where agents representing car parts supplyers need
an Ontology to
interact. This Ontology has been specified through Rational Rose and
edited through
OntoEdit. Agents exchange messages in OXML format.
CURRENT AND FUTURE WORK:
- The Electronic Institution concept has been disigned to
encompass all the stages of a Virtual
Organization (Enterprise) Life Cycle: Announcement of needs,
Formation, Operation and Dissolution.
Our main concern is now to specify what a suitable and effective
"contract"
can be as a result of all the negotiation process.The "E-Contract"
will include a set of procedures
all the agents have agreed upon.
This established "contract" has to be at the disposal of the
Electronic
Institution in order to permit this entity to verify, at the right
time, all the important steps that
should be checked and, if this is the case, to enforce previously
agreed
corrective actions or punishements.
- Following work on the ForEV platform, we have studied the
state-of-the-art literature on
e-contracting, specifically in what B2B contracts are concerned. We
consider e-contracts as the
formalization of a business agreement, which parties agree to sign
because of lack of trust for the
fulfillment of that agreement. The contract will be enforced by an
Electronic Institution
(considered as a trusted third-party) with appropriate services. In
particular, the institution
incorporates a set of norms and rules to be inherited by all contracts
signed within that institution;
it also includes facilities that assist contract construction
(through templates), monitoring and
enforcement. We are also studying deontic logic as a formal approach
to model norms in contracts.
- We are enriching our model of an Electronic Institution, by
considering an enhanced framework
with reputation mechanisms, ontologies, transaction repositories,
templates, and contract monitoring
and enforcement services. As we aim at automating virtual enterprise
contracts, we are defining
requirements for a representation language that considers this complex
setting. We consider
including a flexible level of specification of e-contracts within an
electronic institution,
depending on trust and reputation mechanisms. Furthermore, we intend
to study how agents and the
institution itself can learn to adapt contract requirements to the
reputation of the involved
participants (adopting ideas from contract law and relational contract
theory).
- Also, in order to make it more realistic for agents representing
organisations (enterprises) to know
how their internal processes (production and management processes)
will interfere with the overall organisation
operation, we are now looking at designing sound and correct
inter-organisation network Workflows. Petri-Nets
are good candidates for such representation, test and verification.
- BIAS, the agent-based system for E-Brokering we have
implemented, is now being checked against a credible
scenario, for automatic mediation of Insurance products offers and
needs.
Further developments will imply enhancement of agent negotiation
strategies and
automatic product offers on the Insurance companies side. We reserve
our decision
to go in this direction depending on the impact the prototype will
have on potential interested software houses.
- In order to develop further the ontology-services agent, we
envisage to integrate it with ForEV framework
[Malu03].
Ontology can then be explored in the sense of
helping different agents, representing different companies, to
understand each
other when negotiating their joint participation in a Virtual
Organisation (Enterprise) through
their commitment in supplying complementary parts of the final overall
business process. There are both terminological
and structural differences that may appear in the representation of a
specific domain common knowledge.
Ontology-based services agent will be able to recognize the potential
semantic mismatch and provide
a way of mutual understanding.
People involved: Luís Nunes, Luís Sarmento, Daniel Moura, Eugénio
Oliveira, Rui Camacho, Alexessander Alves
Coordinator: Eugénio Oliveira
Research direction:We are engaged in pursuing two separate
research lines we believe
will be definitely recognized as important in our group. These issues
are an attempt to explore agents'
advanced features:
(i) Multi-agent learning. The main goal of this research issue is to
find an answer to the
following question: "(How) can several different, heterogeneous,
Learning Agents
improve their performance by exchanging information during their own
learning
process?".
(ii) Emotion-based agents' architecture. Through this research issue
we would like to answer another
important question: "Will it be possible to escape from usual
utility-based
decision functions in which decision-making for autonomous agents is
concerned?"
Multi-Agent Learning
Research goal:(How) can several different Learning Agents improve
their
performance by exchanging information during their own learning
process?" that is the question.
RECENT WORK (2003):
- In order to answer that question, we have been studying the
effects of
exchanging information during the learning process in heterogeneous
groups of
agents in controled, and somewhat simplified, scenarios, with the
objective of
detecting possible improvements of agents' individual and global
performances.
We are using communication and heterogeneity to improve agents'
learning performance in
Environments that are:
partially observable and dynamic;
including several Agents dealing with similar problems although using
different learning algorithms
- To achieve the above mentioned goal, and having in mind that
first question,
a method for information exchange during the learning process based
on the
exchange of advice amongst learners has been developed. The learning
environment launches several learners solving different instances of
the same
problem. The instances of the problem may be either totally
independent, or
similar parts of the same global problem. Agents are learning either
through Reinforced
Learning (getting feedback from the environment as it is the case with
Evolutionary
Algorithms and Q-Learning) or supervised learning as it is the case
with backpropagation.
Agents may be at different learning stages: Exploration, Novice,
Intermediate, Expert.
[Oli03a], [Nun03a], [Nun03b], [Nun03c],
[Nun03d], [Nun03e].
As an example in one of our learning environments, agents try to
control traffic lights
in different crossings. Experiments with disconnected crossings have
proved that
advice-exchange, even in its simplest form, is effective. Current work
is focused
on solving the problems that appear when agents share the same
environment and
their actions affect others. In order to analyze the problems that
emerge when
several agents are acting concurrently in the same environment a set
of experiments
in the Pursuit Problem was made [Nun03e]. Results obtained
allowed us to detect and solve
several of the problems that caused disturbances in the learning
process due to
negative interactions between heterogeneous agents' actions or between
the self-learning
algorithms on one hand, and advice-exchange on the other.
Giving advice consists on sending the best response an agent (taking
the role of
advisor) can give to the problem being solved considering the state of
the problem
as seen by another agent (the advisee). The advisee uses this
information as input
to a supervision mechanism. The way the advisee uses information
depends on the
expected quality of the advice given by the advisor and a measure of
trust kept by
the agent based on the result of previous advice given by the same
advisor.
Several other mechanisms, such as providing unsolicited advice and
combining
advice, are under study.
- a simpler traffic light control system including adaptation has
also been developed
and is reported in [Dia03].
CURRENT AND FUTURE WORK:
- We are now evaluating this method on the simulated traffic
control problem.
The simulation is similar to the one used by the
Gerhard-Mercator-Universität
Department of Physics of the University of Duisburg (Germany) to study
traffic
phenomena. This simulation has been built using Java2 and C++, running
on Linux.
- Our approach and results have been published and extensively
discussed in the
"Adaptive Agents and Multi-Agent Systems" AAMAS-3 workshop collocated
with AISB'03
conference [Nun03e], and the interest generated by this approach
lead to the
publication of several other works including an article in a journal
[Nun03a]
and a book chapter [Oli03a]. The paper [Nun03c] got a
nomination for the
best paper at CIA'03.
- The tests are now being done about the interaction between agents that
use
Reinforcement Learning and Evolutionary Algorithms, although the
approach is, in
many respects, generalizable to other learning algorithms. Simulation
uses real traffic
data from a portuguese town. We want to be sure about "poor" agents
performance improvement
at the level of the best ones as well as whether agents interactions
become stable or not.
- Current and future work will focus on refining the advisor
selection process,
based on the concepts of mutual trust and self-confidence, concepts
that dynamicaly evolve
with the agents experience. Identifying teams of agents and
influencing team members on
the choice of a specific advisor will also be tried out through advice
and information exchange.
It may also be interesting to see if team supervisors will emerge from
the interactive learning process.
Other issues include combination of advice from several different
sources and dealing with unsolicited
advice and influence.
Extending this approach to other different learning algorithms and
testing its effectiveness in
problems of traffic-control simulation will be done. Other problems,
such as
communication networks and band-width management are under study as
possible applications.
Numerical Reasoning in Inductive Logic programming (ILP)
Research goals: To enhance an existent Inductive Logic Programming learning system with numerical capabilities.
Inductive Logic Programming (ILP) has been very successful in applications
involving classification problems. ILP algorithms may easily take advantage
of expert provided information relevant for the induction task. Theoretically
there are no constraints on the nature of such expert information. Having that
in mind we consider the possibility of collecting and making available to an
ILP system a set of libraries of numerical and statistical methods. These
library may be used by an ILP system in any application requiring numerical
reasoning. With a proper capability to handle numerical applications ILP may
widen the range of successful applications where it can by used.
FUTURE WORK:
- The goals of this work are two folds: i) development of a set of libraries
incorporating numerical and statistical methods relevant for applications
requiring numerical reasoning; ii) adapting and extending existing ILP systems
to improve their performances in such applications.
- The first line of research includes the development of general purpose
libraries for numerical reasoning and also more specific ones adequate for
specific application with great practical interest like Temporal series. The
second line of research includes substantial improvements in current ILP
systems. It will be necessary to include in ILP systems statistical methods
and changes in the search methods used.
- We will identify the set of interesting applications where our developments will be evaluated.
Emotion-based Agents
Research goals: The second question to be answered is: Will it be
possible to escape
from usual utility-based decision functions in which decision-making
for autonomous agents is concerned?
We are pursuing research efforts towards the understanding how
emotion-like concepts
can endow agents' architecture with more sophisticated, although still
reliable,
decision-making capabilities. New agents' architectures have been
proposed and
experiments are being done in simple simulation scenarios.
Although the study of emotion in the realm of Artificial Intelligence
is not totally new
and has been addressed by Simon, Minsky, Sloman and Croucher among
others, recently much
more attention has been
devoted to this subject by several researchers like R. Picard. This
renewed effort is
being motivated by trends in neuroscience (see A. Damásio's recent
work), that are helping
to clarify and to establish new connections between high level
cognitive processes, such
as memory and reasoning, and emotional processes. These recent studies
point out the
fundamental role of emotion in intelligent behaviour and
decision-making. From our
perspective, as engineers and computer scientists, we are mostly
interested in studying
the functional aspects of emotional processes. Particularly, we aim at
understanding how
emotional mechanisms can improve cognitive abilities, such as
planning, learning and
decision-making, for hardware and software Agents.
RECENT WORK (2003):
- After having proposed what we believe to be an innovative
emotion-based agent architecture
we came to the conclusion that, in order to make experiments that
could be evaluated, we needed
to develop a software platform enabling an apropriate simulation. The
main requirements for this
needed simulation environment were: (1) high level of complexity
for the participating Agents; (2) real-time, highly dynamic,
computational demands; (3) multiple
concerns at stake;(4) overall goals asking for a Multi-Agent System
approach; (5) closeness to a
real-world problem.
- Most of our recent work was then focused on the development
of the Pyrosim simulation platform, with the aim of creating a
suitable
simulation environment for the development of Emotional Agents.
The Pyrosim platform simulates a forest environment where a team of
Agents is placed to fight
an ongoing fire. Agents representing fire fighters deal with all kind
of realistic constraints
(water availability, their own energy and acceleration, vegetation
type and density, terrain slope,
wind...). The platform besides providing all the simulation
environment also alows agent
communication. The core of the Pyrosim Platform includes two basic
elements:
1. the Pyrosim Server application, responsible for running all the
simulation
logic. It contains the environment's model and updates the state of
every entity in each
simulation cycle.
2. the Agent Skeleton layer that provides a convenient interface for
creating customized
Agents. It manages all low level communication between a customized
Agent and the Pyrosim Server.
- There is also another application that is very useful for
monitoring the state
of the simulation:
the Pyroviz. The Pyroviz allows the developer to visualize almost in
real-time
what is happening during the entire simulation through a 3D rendered
scene. The Pyrosim platform
does not provide any Emotional Mechanisms.
- We have been proposing an agent architecture that includes
several emotional-like
mechanisms, namely: emotional evaluation functions, emotion-biased
processing, emotional
tagging and mood congruent memory.
These emotional-like mechanisms are intended to provide agents with
increased performance
and adaptability in real-time environments.
Previously, we have divided emotional phenomena in 3 different
categories: specific emotions,
moods and emotional dispositions. We are now concerned with the
dynamics of emotional
mechanisms. Emotional Accumulators (EA) couple with Emotional
Evaluation Functions
(EEF) to build another element of our agent's architecture, the Basic
Emotional Structure similar
to well known emotions ("Fear", "Anxiety",
"Self-confidence",...). We want to enable dynamic
variations of those parameters that influence the agents' planning
capabilities to achieve specific
goals.
There is a very strong link between emotion and memory, a link that
has several
functionalities associated. One of them is emotional tagging. Instead
of being simply stored in
memory, information is first marked with an emotional tag, relating
that information with
the current emotional state of the agent. The tagging procedure is
itself important because
it allows selecting which information should be stored either in
long-term memory or in short-term
memory or simply discarded.
- A revised
implementation of Emotion-base Architecture was started, following a
more
refined version of the model previously developed. Details about the
current
model are given in [Oli03b].
CURRENT AND FUTURE WORK:
- Future work will be focused in developing a complete
implementation of the
Emotion-based Architecture, with the Pyrosim scenario in mind. Key
concepts on
Emotion-based Architectures are:
- (i) Emotional Evaluation Functions;
- (ii) Emotional State;
- (iii) Emotional Accumulators;
- (iv) Basic Emotional Structures;
- The next step will then be experimenting and testing specific
Emotional
Mechanisms using the Pyrosim simulator. We will be trying to test how
Emotional
Mechanisms such as "Fear", "Anxiety" and "Self-Confidence" may be used
as:
- Information for internal processes (Emotion as Information)
- Changing internal processing parameters (Emotion as a Process
Control
Mechanism)
- Balance computational effort and manage resource allocation
(Emotion and
Resource Allocation Mechanisms)
- Generate global processing modes (Emotion and Information
Processing
Strategies)
People involved: Luís Paulo Reis, Maria Benedita Malheiro, Sérgio
Louro,
Eugénio Oliveira (plus students holding a scholarship:Rui Ferreira
and Rui Sampaio and external collaboration:
IEETA/U.Aveiro, ISR-Porto CEMAS-UFP)
Coordinators: Eugénio Oliveira and Luís Paulo Reis
Research direction: Coordinating teams of autonomous (or
semi-autonomous) agents that perform in rich, dynamic, both
competitive
and adversarial environments is a major aim of this work line. For
this objective, we are exploring
several research directions that can be seen as complementary:
- (i) Developing new coordination protocols that enable teams of
agents to perform complex tasks in open
multi-agent environments
- (ii) Organising and making available knowledge, languages and
protocols for enabling agents' teamwork;
- (iii) Defining methodologies for analyzing team behavior and to
use this analysis for coaching teams of autonomous agents;
- (iv) Design and implement an agent-based common framework
suitable for controlling teams of cooperative robots
(either physical or simulated) playing in RoboSoccer-like
competitions or performing other team complex tasks in
dynamic domains;
- (v) Development of realistic multi-agent simulators enabling
the analysis of team coordination methodologies
for performing complex tasks in dynamic environments as it is the case
with a Coastal Ecosystems Simulator
- The research conducted along this line, may be also partially
applied to several other very useful social
areas, like mine clearance, land exploration, control of hospital
robots, public transport coordination, satellite
control, battlefield scenarios, cleanup of radioactive and toxic
contamination and other problems that imply team
coordination in dynamic environments
Conflict Resolution in Decision Support Systems
- Previously concluded work in this research direction, includes
DiPLoMAT
prototype (Distributed Project Location Multi-Agent based Testbed).
DiPLoMAT applies most of the theoretical work on conflict resolution
done
before, to the Project Location assessment domain. Evaluation Agencies
have
to identify the project land requirements (area, natural resources,
transports, price, etc.), and finding an adequate location for that
specific
project. The achieved result is an Intelligent Decision Support System
to
assist the project team in finding adequate projects' locations which
comply
with the applicable legislation and satisfies the project
requirements.
Multi-Agent Teams' Coordination
RECENT WORK (2003):
- Simulated Soccer Team: Our Simulated soccer team - FC Portugal
(developed in collaboration
with IEETA/Univ.Aveiro), ranked 5th in RoboCup 2003 competition held
in Padova, Italy;
- Coach Agent: Our Coach agent - FCPortugal Coach - ranked 2nd in
the 2003 coach competition
in the RoboCup competition that took place in Padova;
- Other RoboCup teams: We have developed some simple methodologies
for
coordinating teams of physical robots and applied them in the context
of
5dpo RoboSoccer small-size and middle-size league teams (developed by
ISR-Porto).
- Development of a Sony legged RoboSoccer team in the context of
Portus and LEMAS projects
(together with ISR-Porto). Our Legged league team FC Portus, ranked
5th in RoboCup 2003 held
in Padova;
- Coordination of Teams of Homogeneous/Heterogeneous Agents in
Adversarial Environments. We
proposed several coordination methodologies for dynamic spatial
domains, namely: Strategic
coordination, Situation Based Strategic Positioning (SBSP), Dynamic
Positioning and Role
Exchange (DPRE).
- Coordination using High-Level Communication. We have proposed
Intelligent Communication
policies based on appropriate (multi-level) World State
knowledge(ADVCOM) together with a way of
balancing strategic and active communication.
- Coordination without Communication. We have proposed some
opponent modeling and teammate
modeling techniques enabling coordination without communication. We
also have developed a more
adequate perception mechanism called Strategic Looking Mechanism (SLM)
for coordination without
communication
- Partial Hierarchical Coordination. We have developed techniques
enabling a team of autonomous
agents to integrate coach advice in their reasoning processes,
together with their local reasoning process.
- A Visual Debugger for analysing intelligent agent-based players
was improved and released as well as
COACH UNILANG, a standard Language for Coaching a (Robo) Soccer Team.
- A new graphical tool called Team Designer enabling easy
definition of a complete soccer strategy by a
human designer was developed. This tool has a simple automated coach,
a game analyzer and a graphical
visualizer merged into a complete coaching environment.
- Multi-agent realistic camera control was introduced in our
Graphical 3D Visualizer for simulated
soccer games.
CURRENT AND FUTURE WORK:
- Definition of new coordination protocols for our simulated
soccer team (in the context of FC Portugal -
New Coordination Methodologies Applied to the Simulation League
Project - FCT/POSI/ROBO/43910/2002);
- Definition of new methodologies for intelligent perception,
teammate and opponent modeling and multi-agent
communication (in the context of FC Portugal project and LEMAS -
Learning in Multi-Agent Systems in the RoboCup
Sony Legged League project - FCT/POSI/ROBO /43926/2002);
- Enhancing the definition of a COACH UNILANG as a general
language to enable a special agent ("coach") to
supervise a team of co-operative robots.
- Research on opponent modeling and automated coaching and
enhancement of our automated coach with
intelligent resource allocation and learning abilities for tactical
selection;
- Developing a Sony legged
RoboSoccer team in the context of Portus and LEMAS projects (together
with ISR-Porto).
- Development of multi-agent learning methodologies for selecting
the best coordination methodology for each
situation;
- Increasing the co-operation with ISR-Porto (in the context of
5DPO, Portus and LEMAS projects), IEETA-Aveiro
(in the context of FC Portugal project) and CEMAS-UFP for the
developement of a more realistic multi-agent
ecological simulator.
Coordinator: Eugénio Oliveira
People involved: Alexessander Alves, João Luís Pinto,Hugo Proença,
Guilherme Pereira, Rui Camacho, Eugénio Oliveira
Research direction: To apply agent architectures, negotiation
protocols and learning algorithms to specific
application domains.
Communications network management
Research goal: To apply learning algorithms to improve resource
allocation in multi-class packet
switched networks. The system will be applicable to multi class
settings where decision-making
problems are exceptionally complex.
RECENT WORK (2003):
- We have tried several different methods for Time Series Analysis
to deal with all the
past information on traffic control in multi-class packet switched
networks. The objective was
to conceive a learning system that adapts to changing traffic
conditions and predict future traffic
conditions based on past traffic patterns.
Both Deterministic Linear and Non-Linear methods as well as Stochastic
methods have been tried out.
Most recent work has been done in order to accessadequacy of Inductive
Logic programming (ILP) for
Time Series Analysis automation in the context of traffic engineering
of data Communications Networks
[Alv03b].
Our proposals included improving ILP systems with numerical reasoning
capabilities as well as to provide
those ILP systems with apropriate background knowledge for Time Series
Analysis.
We may say that results were improved when compared with statistical
Time Series methods [Alv03a].
IndLog, an ILP system previously developed by R.Camacho, and YAP
prolog language were the basic
software tools in which our modifications and extensions were
included.
CURRENT AND FUTURE WORK:
- We are now applying our Inductive Logic Programming algorithm
[Alv03a] to time
series
data. The models generated by the ILP algorithm were expectd to give
accurate predictions of
the observed data over the "lead-time" period and they also should
contribute to the human
understanding of the network behaviour. Many experiments have to be
done.
A complete multi-agent system managing the allocation of all available
resources in multi-class
packet switch networks and using the induced prediction capabilities
will be specified and,
hopefully, implemented.
Electrical Energy e-Market
Research goals: Current European efforts for the establishment of
both de-regulated
Electrical Energy Markets and Electronic Commerce platforms can be
brought together through
appropriate multi-agent platforms for autonomous agents trading
interaction.
RECENT WORK (2003):
- In the specification of the multi-agent system encompassing the
needed functionalities
for the Electrical Energy e-market, we have untill now emphasising
security procedures,
accountability of the communications, good performance and software
portability. Also,
integration with legacy systems has been privileged.
- The Agents' architecture has been proposed and all the
interaction protocols specified.
Giving the choices of using XML and FIPA-ACL, it was settled that
message transfer should be
made using HTTP POST requests (both from each agent to the
facilitators and from this one to
specific advisor agent). Also Client requests are made using CET
requests. All interactions
use MIME type text/XML. Market operator acts as a message router.
- There are two different "operators" in the system: Market
operator who manages the trading
interaction between the agents in the market, and the System operator
managing the market interaction
with the power system, checking for the feasibility of the market
operation. The kind of interaction
we have implemented simulates a spot market where bids are on power,
marginal costs and hour of the day.
- In our Electricity E-Market, agents authenticate through digital
certificates, while messages between
the market operator and the market agents are digitally signed. We
have
selected the TLS/SSl protocol and, as for the message digital
signatures is concerned, the
open standards are being used. They rely on classical MAC and
cryptography algorithms used in
SSL. Market operator is seen as a trusted
third partner, responsible for registration, auctions and matching
bids and offers.
CURRENT AND FUTURE WORK:
- We are now in the process of implementing a prototype for the
Electrical Energy e-Market
agent-based system. A first scenario will be specified to check
secure and reliable agent interaction.
A secure Multi-Agent System framework making available negotiation
algorithms tuned for this
specific domain is to be achieved. We foresee the implementation of a
prototype to showcase
all the technological options. Open source tools and libraries are
being used.
Controlling a Metropolitan Railway System through Agents
Research & Development goals: To specify and implement a
generic
multi-agent system suitable for automatic control of a subset of a
railway system.
RECENT WORK (2003):
- During the year 2003 we have specified and implemented MARCS
(Railway control Multi-Agent System)
that proves, in a simulated environment,that by using communication it
becomes possible to take
correct control decisions and potential conflicts may be avoided. A
Master thesis report was
produced [Pro03].
MARCS makes agents representing trains, train stations and sub-network
supervisors, to cooperate
in order to preview whether or not conflicts can occur. A conflict
arises when a resource,
here a joint in a railway line or a station train-stop, is
simultaneously required by more than
one train.
- MARCS is a decentralized control system that better deals with
local exceptions and also learns
to adapt to future potential conflicts [Pro03a]. Agents (trains,
train stations, sub-network
supervisors) exchange
either plans or other specific information to help in their own
reasoning to coordinate their
speed and avoid potential conflicts. The system becomes
fault-tolerant, once whenever a sub-network
supervisor is down, it immediatly reconfigures itself to re-distribute
the responsibility by other
supervisor agents.
- Each potential confict that has been solved by the system is
then recorded. The all set of previous
examples (avoided conflicts) is dealt with by means of an unsupervised
learning algorithm - APRIORI
(Agrawal, Strikant)to induce rules of behaviour for future application
in similar situations.
CURRENT AND FUTURE WORK (2004):
- We intend to finalize this work by evaluating the results (have
been potential conflicts
correctly antecipated?) after
a number of different experiments in the simulated network provided by
MARCS.
Also an analysis on the possible generalisation to different, although
closer application domains, will be provided.
Agent-based Travel Services platform
Research & Development goals: To specify and implement a
generic
multi-agent system platform suitable for supporting automatic Travel
Services Agency. This research has been motivated by the "Personal
Travel Assistant"
application from British Telecom and the Trading Agent Competition.
RECENT WORK (2003):
- We have specified and implemented a platform combining the
distributed nature of a multi-agent system with the security
and encryption facilities
provided by web servers, separating data from knowledge in
a
concurrent common area. We have
also endowed the agents with learning capabilities directed to two
different
aspects: Reinforcement Learning for bidding policies and a kind
of
Concept
Learning technique for user profiling. The functionality of all
the
proposed multi-agent system features is now being illustrated
through an agent-based Travel Services application.
- The
system allows flight and hotel booking from local or remote
customers. There are three main types of agents: customer, company
and hotel agents who represent the respective entities. There is also
a facilitator, a press agent and a softbot. The facilitator is
responsible for storing travel packages bundled by company and hotel
agents. The press agent is an agent who will publish customer
complaints as well as good impressions. It serves as a mean to
establish company and hotel agent reputation. The softbot is capable
of extracting information from real world web pages updating company
and hotel agent information systems.
CURRENT AND FUTURE WORK:
- This work will be complete after experimentation in scenarios
where gains from the agents learning features,
concerning both user profiling and negotiation adaptation, can be
highlited.
©LIACC, Universidade do Porto, 2004
| | | D.1.3 NIAD&R: Plan for 2004 |