ILIAS Seminars | ||||
Future talks |
Past talks |
Contact | ||
ILIAS is the Interdisciplinary Lab for Intelligent and Adaptive Systems at the University of Luxembourg. For the ILIAS webpage, see here. The ILIAS seminars are held at Campus Kirchberg. The seminars are coordinated by Wojtek Jamroga. In case of questions, remarks, or suggestions, feel free to email me. Speaker:
Koen Hindriks (Delft University of Technology) Title:
Agent Programming in GOAL
Abstract:
I will introduce and discuss the main concepts of the rule-based agent programming language GOAL (beliefs, goals, rules, and modules), discuss how these agents interact with environments (action and percepts), and communication in a multi-agent system. I'll also present various examples of environments, including classic AI toy problems such as the Blocks and Wumpus World, games such as UT, and robots.
Speaker:
Matthias Thimm (University of Koblenz) Title:
Classification and Strategical Issues of Argumentation Games on Structured Argumentation Frameworks
Abstract:
This talk deals with strategical issues of arguing agents in a multi-agent setting. We investigate different scenarios of such argumentation games that differ in the protocol used for argumentation, i. e. direct, synchronous, and dialectical argumentation protocols, the awareness that agents have on other agents beliefs, and different settings for the preferences of agents. We give a thorough investigation and classification of these scenarios employing structured argumentation frameworks which are an extension to Dung's abstract argumentation frameworks that give a simple inner structure to arguments. We also provide some game theoretical results that characterize a specific argumentation game as strategy-proof and develop some argumentation selection strategies that turn out to be the dominant strategies for other specific argumentation games.
Speaker:
Marek Bednarczyk (Polish Academy of Sciences) Title:
Hypernets: a formalism to model and reason about mobility
Abstract:
The purpose of the talk is to present some results and directions
of research in the area of mobility. In particular we present the
idea of hypernets in which agents supervise the activities of other
agents in hierarchical manner.
The model is based in Petri nets, i.e., an agent is a Petri net.
Thus, the formalism falls within the ,,nets-within-nets'' group of
frameworks. This has distinctive advantages: under certain assumptions
one can translate a hypernet, even with agent creation allowed, to
a finite P/T net system with isomorphic state space. Thus, certain
important properties, like reachability of a state from a given one,
are decidable, although at very high cost.
Since non-trivial fragments of temporal logics tend to have undecidable
model-checking problem one is also tempted to turn to Petri nets
which support invariant analysis as a method to verify interesting
properties of systems with possibly infinite state spaces.
Speaker:
Pierre Manneback (Polytech-Mons) Title:
Exploitation of Parallel Heterogeneous Architectures for multimedia processing
Authors:
Sébastien Frémal, Sidi Ahmed Mahmoudi, Pierre Manneback
Abstract:
Computers consist mainly on two kinds of processors: Central Processor Unit (CPU) and Graphics Processor Unit (GPU). CPUs are used in personal computers as the main processing unit. GPUs were introduced in the late 1990s to assist central processors in display operations. Moreover, they can be used for accelerating different applications by applying parallel treatments on massive amount of data. Furthermore, there are computers composed of multiple CPUs and GPUs presenting heterogeneous architectures. More particularly, image and video processing algorithms can benefit from these platforms by exploiting effectively their computing units in parallel. We propose a general framework for multimedia processing on parallel (GPU) and heterogeneous architectures. This framework is based on exploiting the full computing power of hybrid platforms (Multi-CPU/Multi-GPU). The proposed framework enables to select firstly the computing units (CPU or/and GPU) for processing, and secondly the methods to be applied depending on the type of media to treat. Indeed, we employ an efficient scheduling strategy based on the history of the computing times of precedent tasks. We exploit also CUDA streams in order to overlap data transfers by kernels executions within multiples GPUs. Experimentations have been conducted using different types of media (HD images, databases of medical images, HD videos) within different applications. These results showed a global speedup ranging from 10 to 50, by comparison with sequential CPU implementations.
Speaker:
Nils Bulling (Clausthal University of Technology) Title:
How to Achieve and How to Verify Norm Compliance of Resource-Bounded Agents?
Abstract:
The verification and modeling of multi-agent systems is an important topic that has attracted much attention in recent years. Resources, however, have only recently been studied as simple extensions of well-known logics. In this talk I explore the question: Where are the limits of what can be verified about resource-bounded agents? I try to answer this question by considering several natural logic-based settings that may arise and prove that verification is usually undecidable apart from bounded or otherwise restricted settings.
In the second part of my talk, I turn to the question of how agents can be incentivised to comply with the norms of a MAS. I show how concepts from mechanism design can be used to formally analyze and verify whether specific normative behaviors can be enforced (or implemented) if agents follow their subjective preferences.
The behavior of agents strongly depends on available resources (incentives themselves can be seen as resources). Hence, a natural question arises: How to achieve and how to verify norm compliance of resource-bounded agents? I would like to address this question in my future research.
Speaker:
Artur Meski and Maciej Szreter (Polish Academy of Sciences, Warsaw) Title:
Bounded Model Checking Linear Time and Knowledge Using Decision Diagrams
Abstract:
In our talk we are going to present a novel approach to verification
of multi-agent systems by bounded model checking for Linear Time
Temporal Logic extended with the epistemic component (LTLK), which is
interpreted over interleaved interpreted systems. Our method is based
on binary decision diagrams that are used for representing the verified
system. We describe the algorithm and provide its experimental
evaluation together with the comparison with another tool. We also
provide an overview of other verification tools for multi-agent systems.
Speaker:
Francois Schwarzentruber (ENS Chachan/Bretagne) Title:
Tableau Method and NEXPTIME-Completeness of DEL-Sequents
Abstract:
Dynamic Epistemic Logic (DEL) deals with the representation of
situations in a multi-agent and dynamic setting. It can express in a
uniform way statements about:
(i) what is true about an initial situation
(ii) what is true about an event occurring in this situation
(iii) what is true about the resulting situation after the event has
occurred.
After proving that what we can infer about (ii) given (i) and (iii) and
what we can infer about (i) given (ii) and (iii) are both reducible to
what we can infer about (iii) given (i) and (ii), we provide
a tableau method deciding whether such an inference is valid. We
implement it in LOTRECscheme and show that this decision problem is
NEXPTIME-complete. This contributes to the proof theory and the study of
the computational complexity of DEL which have rather been neglected so far.
Speaker:
Elad Dokow (Bar Ilan University) Title:
Models of Manipulation on Aggregation of Binary Evaluations
Abstract:
We study a general aggregation problem in which a society has to determine its position
on each of several issues, based on the positions of the members of the society on those issues.
There is a prescribed set of feasible evaluations, i.e., permissible combinations of positions
on the issues. Among other things, this framework admits the modeling of preference aggregation,
judgment aggregation, classification, clustering and facility location. An important
notion in aggregation of evaluations is strategy-proofness. In the general framework we
discuss here, several definitions of strategy-proofness may be considered. We present here
3 natural general definitions of strategy-proofness and analyze the possibility of designing
an annonymous, strategy-proof aggregation rule under these definitions. (Joint work with Dvir Falik)
Speaker:
Malgorzata Sterna (Poznan University of Technology) Title:
Late Work Scheduling Problems
Abstract:
We present scheduling problems with the late work criteria - non classical performance measures. Late work objective functions estimate the quality of a schedule based on durations of late parts of jobs, not taking into account the amount of delay for fully late jobs. We provide a formal definition of the late work parameter and compare the criteria based on it with other classical performance measures. Moreover, a few real world applications of the late work objective function are given. Then we present selected results obtained for late work scheduling problems with a single machine, parallel and dedicated machines.
Malgorzata Sterna earned Master degree in Computer Science (Distributed
Computer Systems) at Poznan University of Technology in 1996. At the same University, she got Ph.D. degree and Habilitation in Computer Science (Scheduling Theory, Theory of Algorithms) in 2000 and 2007 respectively.
Malgorzata Sterna is an assistant professor at the Faculty of Computing
and Information Science at Poznan University of Technology and associate
professor at the Institute of Computing Science at State Higher Vocational School in Gniezno. Her fields of interest include scheduling theory, complexity theory, algorithms design, selected aspects of graph theory, combinatorial optimization and bioinformatics.
Malgorzata Sterna got the stipend of the Foundation for Polish Science in 2000 and award of the Polish Academy of Sciences from the IV Division of Technical Sciences in the field of Computer Science in 2008. She has collaborated with Université Joseph Fourier (Grenoble),
Otto-von-Guericke-Universität (Magdeburg), Universität Bonn, Autonomous
University of Baja California (Tijuana) and University of Nottingham.
Malgorzata Sterna is a reviewer for 14 journals from ISI Master Journal
List and for the Polish Ministry of Science and Higher Education. She is a member of Polish Accreditation Committee.
Speaker:
Jean-Yves Beziau (Universite de Neuchatel) Title:
The Power of the Hexagon
Abstract:
In this lecture I will present and discuss the hexagon of opposition, an
improvement of the square of opposition due to Robert Blanché.
The hexagon of Blanché is made of a triangle of contrariety and a triangle
of subcontrariety linked together by the relations of contradiction and
subalternation. This hexagon includes the traditional square and can be
extended to three dimensional objects giving a better understanding of
modalities and negations.
I will also show how this simple logical structure based on three
oppositions can be applied to many different concepts ranging from logic
to music, through metalogic, economy and semiotics.
References:
J.-Y.Beziau and D.Jacquette, Around and beyond the square of opposition,
Birkhäuser, Basel, 2011.
J.-Y.Beziau and G.Payette, Special Issue of Logica Universalis on the
Square of Opposition, vol.2, n.1, 2008.
J.-Y.Beziau and G.Payette, New perspectives on the square of opposition,
Peter Lang, 2011.
R.Blanché, Structures intellectuelles - Essai sur l'organisation
systématiques des concepts, Vrin, Paris, 1966
Speaker:
Laurent Doyen (CNRS Cachan) Title:
Partial-Observation Stochastic Games: How to Win when Belief Fails
Abstract:
We consider two-player stochastic games played on finite graphs with
reachability (and Buechi) objectives where the first player tries to ensure
a target state to be visited (or visited infinitely often) almost-surely, i.e., with
probability 1, or positively, i.e., with positive probability, no matter
the strategy of the second player.
We classify such games according to the information and to the power
of randomization available to the players. On the basis of information,
the game can be one-sided with either (a) player 1, or (b) player 2
having partial observation, or two-sided with (c) both players having
partial observation.
On the basis of randomization, (a) the players may not be allowed to use
randomization (pure strategies), or (b) they may choose a probability
distribution over actions but the actual random choice is external and not
visible to the player (actions invisible), or (c) they may use full
randomization.
Our main results for pure strategies are as follows:
(1) For one-sided games with player 2 perfect observation we show that (in
contrast to full randomized strategies) belief-based strategies are not
sufficient, and we present an exponential upper bound on memory both for
almost-sure and positive winning strategies;
we show that the problem of deciding the existence of almost-sure and positive
winning strategies for player 1 is EXPTIME-complete.
(2) For one-sided games with player 1 perfect observation we show that
non-elementary memory is both necessary and sufficient for both almost-sure
and positive winning strategies.
(3) We show that for the general (two-sided) case finite-memory strategies are
sufficient for both positive and almost-sure winning, and at least non-elementary
memory is required.
We establish the equivalence of the almost-sure winning problems for pure
strategies and for randomized strategies with actions invisible.
Our equivalence result exhibits serious flaws in previous results in the literature:
we show a non-elementary memory lower bound for almost-sure winning whereas an
exponential upper bound was previously claimed.
Speaker:
Chiaki Sakama (Wakayama University, Japan) Title:
A Logical Account of Lying
Abstract:
The current work aims at providing a formal account of lying - a dishonest attitude of human beings. We first formulate lying under propositional modal logic and present basic properties for it. We then investigate why one engages in lying and how one reasons about lying. We distinguish between offensive and defensive lies, or deductive and abductive lies, based on intention behind the act. We also study two weak forms of dishonesty, bullshit and deception, and provide their logical features in contrast to lying. We finally argue dishonesty postulates that agents should try to satisfy for both moral and self-interested reasons. (Joint work with Martin Caminada and Andreas Herzig.)
About the speaker:
Chiaki Sakama graduated from Kyoto University in 1985 and received
a Dr. Eng. degree in computer science in 1995. He worked at Toshiba
and joined the Fifth Generation Computer Project in Japan.
He has been at Wakayama University since 1995 and is currently a
Professor in the Department of Computer and Communication Sciences.
He has been engaged in research on logic programming, nonmonotonic
reasoning, and machine learning. His recent research interests involve
in theoretical foundations of multiagent systems and social intelligence.
Speaker:
Llio Humphreys (University of Turin) Title:
Eunomos, a legal document management system based on legislative XML and ontologies
Abstract:
This talk will discuss the ongoing work and future developments on the Eunomos software, an advanced legal document management system that enables users to research laws and legal concepts, and make sure they comply with their legal obligations. Eunomos is based on legislative XML representation of laws which are retrieved automatically from institutional legislative portals, and is complemented by a tool for building legal ontologies called Legal Taxonomy Syllabus. The software can help law firms, in-house legal offices and law scholars by offering them an environment which makes laws easier to navigate, annotate and understand, using automatically generated hyperlinks to referenced legislation, an extensible and updatable ontology which provides current and previous definitions for norms and concepts within any specific context, and an alert system that specifies existing legislation affected by new legislation. It
is intended that the system will be used in the first instance by banks and insurance companies to help them comply with strict regulatory duties in a highly complex and constantly evolving area of law.
Speaker:
Srdjan Vesic (IRIT Toulouse) Title:
A New Approach for Preference-Based Argumentation Frameworks
Abstract:
Dung's argumentation framework consists of a set of arguments and an
attack relation
among them. Arguments are evaluated and acceptable sets of them,
called extensions, are
computed using a given semantics. In the literature, several proposals
have extended this
framework in a way to take into account the strength of arguments. The
basic idea is to
ignore an attack if the attacked argument is stronger than (or
preferred to) its attacker.
Semantics are then applied using only the remaining attacks.
In this talk, we show that those proposals behave correctly when the
attack relation
is symmetric. However, when it is asymmetric, conflicting extensions
may be returned
leading to unintended conclusions. We propose an approach that
guarantees conflict-free
extensions. This approach presents two novelties: the first one is
that it takes into account
preferences at the semantics level rather than the attack level. The
idea is to extend existing
semantics with preferences. In case preferences are not available or
do not conflict with
the attacks, the extensions of the new semantics coincide with those
of the basic ones. The
second novelty of our approach is that a semantics is defined as a
dominance relation on
the power set of the set of arguments. The extensions (under a
semantics) are the maximal
elements of a dominance relation. Such an approach allows not only to
compute the
extensions of a framework but also to compare its non-extensions.
We start by proposing three dominance relations that generalize
respectively stable, preferred and grounded
semantics with preferences. Then, we focus on stable semantics and
provide a full characterization
of its dominance relations and that of its generalized versions. Complexity
results are also provided. Finally, we show that an instance of the
proposed framework retrieves
the preferred sub-theories which were proposed in the context of
handling inconsistency in
weighted knowledge bases.
Speaker:
Nan Li (Autonomous University of Barcelona) Title:
A Liberal Impossibility of Abstract Argumentation
Abstract:
In abstract argumentation, where arguments are viewed as abstract entities with a binary defeat relation among them, a set of agents may assign individual members the right to determine the collective defeat relation on some pairs of arguments. I prove that even under a minimal condition of rationality, the assignment of rights to two or more agents is inconsistent with the unanimity principle, whereby unanimously accepted defeat or defend relation among arguments are collectively accepted. This result expands the domain of liberal impossibility beyond preference aggregation and judgment aggregation, and highlights this impossibility as an inherent tension between individual rights and collective consensus.
Speaker:
Henning Schnoor (University of Kiel) Title:
Epistemic, Probabilistic ATL* with an Application to Security
Abstract:
ATL(*) is a well-established logic to reason about strategic
properties of games. Recently, epistemic variations of ATL have been
introduced that take into account that players in games often only have
partial information on which they can base their decisions, and in
addition allow to explicitly express knowledge-based properties of
games. Additionally, extensions of ATL to probabilistic contexts have
been investigated.
We present QAPI, a new variant of ATL which incorporates the above
features, and allows explicit reasoning about strategies in the object
language. This leads to a very expressive logic that can express complex
strategic properties as equilibria. We obtain bisimulation relations and
model checking complexity results.
As application, we show how to use QAPI to express security properties
of state-observed systems as well as cryptographic protocols. This
implies new decidability results in cryptographic protocol verification.
Speaker:
Paolo Turrini (Utrecht University) Title:
Turning competition into cooperation and cooperation into competition
Abstract:
The present talk discusses the classical problem of
transforming a strategic game into a cooperative one and answers two
questions:
1) can strategic games be characterized in terms of cooperative ones?
The first part of the talk, result of joint work with Wojtek Jamroga and
Valentin Goranko, revisits the issue of correspondence between strategic
games, objects of study of noncooperative game-theory, and effectivity
functions, object of study of cooperative game theory.
The second one, result of joint work with Davide Grossi, proposes a new
approach to cooperative interaction, where players cooperate only in
presence of an appropriate interdependence. The resulting structures can
be nicely analyzed with classical tools.
Speaker:
Rohit Parikh (City University of New York) Title:
The Logic of Campaigning (joint work with Walter Dean)
Abstract:
There is a great deal of existing work on changes in belief states when a public announcement is made. How is this work relevant to campaigning?
In the US, while a presidential election typically takes a single day, the processs of campaigning starts more than a year in advance, with various candidates trying to influence public opinion.
We offer a simple propositional logic based model for this process. We assume that the various issues are represented by certain propositions which may become true or false as the result of a particular candidate becoming elected.
We also assume that various groups of voters of different sizes have wishes as to whether they want a particular proposition to be true or false and who also have a degree of passion for each such proposition representing how much they care.
The candidate has already made some statements indicating how she will act if elected but her positions on some issues may be unclear. How should she speak now in order to increase her chances of being elected?
Speaker:
Nicolas Troquard (University of Essex) Title:
Logics of agents with small models
Abstract:
Possible worlds and relational semantics are commonly used to model
multi-agent systems. However, describing a complex system in terms of
possible worlds is often unpractical. For instance, in MOCHA (a model
checker for ATL), reactive modules are used to overcome this
difficulty: the powers of agents and coalitions are derived from the
ability to control some variables.
In this talk, I will provide evidences that interesting logics with
small models are attainable for a variety of notions: coalitional
ability, dynamicity and imperfect information.
Coalition Logic of Propositional Control (CL-PC) (van der Hoek &
Wooldridge 2005), whose models are directly inspired by reactive
modules, is an example of logics of agents with small models. I will
also present Dynamic Logic of Propositional Assignments (DL-PA) that
is evaluated wrt. simple propositional models. I will show how DL-PA
can simulate CL-PC. Finally, time permitting, I will present one or
two epistemic variants of CL-PC. Axiomatisations, and complexities of
model checking and satisfiability checking will be discussed.
Contains joint work with Wiebe van der Hoek, Michael Wooldridge
(epistemic CL-PC) and Andreas Herzig (DL-PA).
Speaker:
Ulle Endriss (University of Amsterdam) Title:
Complexity of Judgment Aggregation
Abstract:
Aggregating the judgments of a group of agents regarding a set of interdependent propositions, expressed in propositional logic, can lead to inconsistent outcomes. This paradox of judgment aggregation has recently sparked a good deal of interest in Legal Theory, Philosophy, Economics, Logic, and Computer Science. In this talk, I will first give a short introduction to judgment aggregation and then report on our ongoing work aimed at better understanding this problem domain from a computational point of view. Specifically, we have analysed the computational complexity of several problems that naturally arise in the context of judgment aggregation: computing a collective judgment, strategic manipulation, and deciding whether a given class of aggregation problems can be guaranteed not to lead to paradoxical outcomes. This is joint work with Umberto Grandi and Daniele Porello. I will explain how this work fits into the broader research agenda of Computational Social Choice (COMSOC).
Speaker:
Pierre Del Moral (INRIA Bordeaux Sud-Ouest/IMB, France) Title:
Concentration inequalities for mean field particle models (joint work with Emmanuel Rio)
Abstract:
This lecture is concerned with the fluctuations and the concentration properties of a general class of discrete generation and mean field particle interpretations of non linear measure valued processes. We combine an original stochastic perturbation analysis with a concentration analysis for triangular arrays of conditionally independent random sequences, which may be of independent interest. Under some additional stability properties of the limiting measure valued processes, uniform concentration properties with respect to the time parameter are also derived. The concentration inequal ities presented here generalize the classical Hoeffding, Bernstein and Bennett inequalities for independent random sequences to interacting particle systems, yielding very new results for this class of models. We illustrate these results in the context of McKean Vlasov type diffusion models, McKean collision type models of gases, and of a class of Feynman-Kac distribution fl ows arising in stochastic engineering sciences and in molecular chemistry.
Speaker:
Tom Gordon (Fraunhofer Institute Berlin) Title:
The Carneades Argumentation System
Abstract:
Carneades is an argument mapping and analysis application, with a graphical user interface, and a software library for building applications supporting various argumentation tasks. Carneades provides tools supporting a variety of argumentation tasks, including:
Speaker:
Mustafa Ali Turker (Middle East Technical University Ankara) Title:
Mindful Evolution
Abstract:
Let's define an evolutionary process as varying and assessing options on the face of challenges, selecting and expressing the choice, repeating this until a solution construct emerges. It readily follows that a good many collective and cognitive processes fits to this description. However random the choice outcomes may be, only in retrospect their totality is recalled as one meaningful narrative: a consistent chain of causal events. Could it be possible to improve such processes while experiencing them? How can evolution be improved at all while control points are spread wide, internally and externally? Autonomous learning is one such evolutionary cognitive process, where the variety of options increased dramatically thanks to the Web and ICT support. In this seminar, we will dicuss how can the evolutionary flow of the study experience be objectifed using phenomenological principles. A spatio-temporal computer visualisation will be proposed to mediate the flow on-the-fly. The learner can mindfully appraise the construct towards which the flow is currently oriented; guide and redirect. Cognitive Dimensions of Notations framework is used to evaluate the resulting increase in affordance.
Speaker:
Inanc Seylan, University of Bozen/Bolzano Title:
Proving Interpolation in Description Logics Using Mosaic and Axiom Instantiation Techniques
Abstract:
Many description logics have the tree model property, i.e.,
satisfiable concepts always admit tree shaped models. In this
talk I will first show how to draw trees using small but
meaningful pieces called mosaics. Then I will use the mosaic and
axiom instantiation techniques to prove polynomial reductions
from more expressive description logics to less expressive ones.
Finally I will discuss how these reductions can be used to prove
interpolation theorems. Interpolation itself has applications in
query rewriting over databases using ontologies, obtaining
acyclic TBoxes from general ones, and signature decompositions.
Speaker:
David Makinson, London School of Economics Title:
Intuitionistic logic, elementary rules, classical logic
Abstract:
The interplay of introduction and elimination rules for the
propositional connectives is often seen as suggesting a distinguished
role for intuitionistic logic in preference to classical. We prove a
formal result that helps clarify this perspective: intuitionistic
consequence is the least consequence relation over a suitable language
that satisfies all classically correct elementary rules, and discuss its
significance. (joint work with Lloyd Humberstone, Monash)
Speaker:
David Makinson, London School of Economics Title:
Proto-probability functions
Abstract:
In recent years, the study of qualitative uncertain inference has given
rise to the notion of probabilistically sound consequence relations.
They are rather like preferential consequence relations in that they may
fail monotony, but satisfy only conditions that are, in a natural sense,
probabilistically sound. A syntactic account was given by Hawthorne,
although the question of its completeness remains open. The study of
such consequence relations leads naturally to a generalization of
existing accounts of conditional probability itself, such as the
standard ratio/unit definition and the less well known intrinsically
conditional systems of Hosiasson-Lindenbaum, Popper, and van Fraassen.
The idea is to articulate a weakest notion of conditional probability
that suffices to validate the postulates of Hawthorne's system for
probabilistic consequence. We do this in purely-order theoretic terms,
calling it proto-probability, and begin a study of its behaviour.
Speaker:
Chattrakul Sombattheera, Mahasarakham University Title:
Optimal Coalition Structure in Humanoid Robots
Abstract:
Optimal coalition structure has gained much attention
in multi-agent systems research recently. The problem itself is
more of an optimization problem but is also an important ingredient
in solving multiple research problems in multi-agent systems.
The problem is known an NP-hard problem. The research on the
problem so far has focuses on the theoretical part and assumes
some certain computational power. It is a challenge to solve
this problem in bounded-rational agents, as in humanoid robots.
This talk will present an attempt to bridge the theory background
of the problem, which is mainly what I have done in my thesis, and
the practical world as in "Nao" humanoid robots. The first part will
be how can we solve the problem in characteristic function game.
The second part is solving the problem in more practical domains,
including linear, non-linear and supply chains. The last part will be
the on-going work here in Luxembourg: solving the problem in
humanoid robots.
Speaker:
Nils Bulling, Clausthal University of Technology Title:
On the Complexity of Verifying Agents With and Without Memory: A Comparison
Abstract:
In this talk I give an overview of the model checking problems for various strategic logics. Besides the standard logics ATL and ATL*, we discuss ATL+ and show that it is the minimal well-known fragment for which model checking under the perfect recall semantics is harder than for the memoryless semantics. We prove that the model checking problem for this logic under perfect recall is PSPACE-complete.
Speaker:
Artur d'Avila Garcez Title:
Neurosymbolic Cognitive Computation
Abstract:
Three notable hallmarks of intelligent cognition are the ability to draw
rational conclusions, the ability to make plausible assumptions, and the
ability to generalise from experience. Although human cognition often
involves the interaction of these three abilities, in artificial
intelligence they are typically studied in isolation. In our research
programme, we seek to integrate the three abilities within neural
computation, offering a unified framework for learning and reasoning that
exploits the parallelism and robustness of connectionism. A neural network
can be the machine for computation, inductive learning and effective
reasoning, while logic provides rigour, modularity and explanation
capability to the network. We call such systems, combining a connectionist
learning component with a logical reasoning component, "neural-symbolic
learning systems". In this talk, I review the work on neural-symbolic
learning systems, starting with logic programming, which has already
provided contributions to problems in bioinformatics and engineering. I
then look at how to represent modal logic and other forms of non-classical
reasoning in neural networks. The model consists of a network ensemble,
each network representing the knowledge of an agent at a time-point.
Networks can be combined to represent and learn relations
between objects, with interesting potential applications in graph mining
and link analysis in biology and social networks. We claim that this
powerful yet simple structure offers a basis for an expressive and
computationally tractable cognitive model.
Speaker:
Mehdi Dastani (Utrecht University) Title:
Strategic Executions of Choreographed Timed Normative Multi-Agent
Systems
Abstract:
This talk presents a combined mechanism for coordinating
agents in timed normative multi-agent systems. Timing constraints in a
multi-agent system make it possible to force action execution to happen
before certain time invariants are violated. In such multiagent systems
we achieve coordination at two orthogonal levels with respect to states
and actions. On the one hand, the behaviour of individual agents is
regulated by means of social and organisational inspired concepts like
norms and sanctions. On the other hand, the behaviour of sets of agents
is restricted according to action-based coordination mechanisms called
choreographies. In both cases, the resulting behaviour is constrained by
time.
Speaker:
Koen Hindriks (TU Delft) Title:
Preference Reasoning
Abstract:
We are interested in qualitative models of preferences in the context of negotiation. We are after a preference framework that supports reasoning with multiple issues and that is able to handle incomplete information. In this talk I present an argumentation-based framework for the modeling of and automated reasoning about multi-issue preferences of a qualitative nature. The framework presents preferences according to the lexicographic ordering that is both intuitive and well-understood by humans. We discuss some of the issues involved when only incomplete information about preferences is available. We then proceed and discuss a second issue related to incomplete information, namely the absence of objective knowledge from which preferences are derived.
Speaker:
Olivier Pietquin (Supélec, Metz) Title:
Information, Multimodality and Signals
Abstract:
In this talk will be presented the research activities of the Supélec's IMS
group. Supélec is an French engineering school based on 3 campuses
(Gif-sur-Yvette, Metz, Rennes) and IMS is one of the two research groups of
its Metz campus. IMS focuses its research on a situated approach to
information processing. This approach mixes signal processing, machine
learning and distributed computing and aims at building autonomous machines.
IMS applies its research to robotics, man-machine interfaces and intelligent
environments. After a general presentation of the group's research
activities, the talk will focus on typical applications and projects in
which IMS is currently involved. We expect this talk to be an opportunity
for fruitful discussions.
Olivier Pietquin obtained an Electrical Engineering degree from the Faculty
of Engineering, Mons (FPMs, Belgium) in June 1999 and a PhD degree in April
2004. He joined the FPMs Signal Processing department (TCTS Lab.) in
September 1999. In 2001, he has been a visiting researcher at the Speech and
Hearing lab of the University of Sheffield (UK). Between 2004 and 2005, he
was a Marie-Curie Fellow at the Philips Research lab in Aachen (Germany).
Now he is an Associate Professor at the Metz campus of Supelec (France), and
heads the "Information, Multimodality & Signal" (IMS) research group. His
research interests include spoken dialog systems evaluation, simulation and
automatic optimisation, machine learning as well as image, multimedia and
biomedical signal processing.
Speaker:
Valentin Goranko (Technical University of Denmark, Copenhagen) Title:
A Logical Framework for Capturing the Dynamics of Information and
Abilities of Players in Multi-Player Games (joint work with
Peter Hawke)
Abstract:
I will discuss first steps towards a more realistic treatment and
logical formalization of the abilities of players to achieve objectives in
multi-player games under incomplete, imperfect, or simply wrong information
that they may have about the game and about the course of the play.
In this talk, after some motivating examples I will introduce a variation of
the multi-agent logic ATL as a logical framework for capturing the interplay
between the dynamics of information and the dynamics of abilities of
players. This framework takes into account both the a priori information of
players with respect to the game structure and the empirical information
that players develop over the course of an actual play. It associate with
them respective information relations and notions of `a priori' and
`empirical' strategies and strategic abilities. I will discuss the problem
of model checking of statements formalized in the new logic under different
assumptions about the abilities of the players to observe, remember, and
reason.
Speaker:
Célia Pereira (University of Milano) Title:
An Integrated Possibilistic Framework for Goal Generation
in Cognitive Agents
Abstract:
In this talk I will present an integrated theoretical framework,
grounded in possibility
theory, to account for all the aspects involved in representing
and changing beliefs, representing and generating justified desires,
and selecting goals based on current and uncertain beliefs
about the world, and the preferences of the agent.
Beliefs and desires of a cognitive agent are represented as (two
distinct) possibility distributions. In such a framework:
(i) the possibility distribution representing the qualitative
utilities associated with desires are the result of a rule-based
deliberative
process, that is, they depend on the mental state of the agent
and are not given a priori; and (ii) the criteria for choosing goals
take into account not only the fact that goals must be consistent in
the logical sense, but also in the cognitive sense.
Speaker:
Sujata Ghosh (University of Groningen) Title:
On strategy composition and game composition
Abstract:
We argue that it is useful to reason not only about the
existence of strategies for players (in reasoning about games), but
also about what these strategies are, and how players select and
construct them. We study extensive form games and suggest that this
can be carried out in two ways: one by considering a single game, and
studying composition of ``local'' strategies; the other, by looking at
the compositional structure of a given game (in terms of subgames) and
associating strategies that are ``global'' within these subgames. In
each case, we study a propostional modal logic in which such reasoning
is carried out, and present complete axiomatizations of valid formulas.
Speaker:
Paolo Turrini (Utrecht University) Title:
Dependence Theory via Game Theory
Abstract:
The talk will discuss the relation between two independent research
threads in the study of social interaction within multiagent systems:
Game Theory and Dependence Theory. While the former lies on solid
mathematical foundations, for the latter several informal accounts exist,
but no unified formal theory.
It will be maintained that the fundamental relation of Dependence Theory,
"agent i depends on agent j for the realization of goal p",
can be given a natural gametheoretical semantics. Most importantly, it
will be observed how cycles arising from dependence relations
and equilibrium outcomes in games can be related. This allows for the
study of 'agreements', structural transformations of the strategic
interaction, that 'solve' dependence relations, giving rise to a new class
of coalitional games.
The unification presented provides Dependence Theory with the sort of
mathematical foundations which still lacks,
and shows how Game Theory can incorporate dependence-theoretic
considerations in a fully formal manner.
The talk is based on joint work with Davide Grossi (ILLC, Amsterdam).
Speaker:
Nicolas Schwind (Universite d'Artois) Title:
Merging Qualitative Constraint Networks Using Propositional Logic
Abstract:
Spatial or temporal reasoning is an important task for many
applications in Artificial Intelligence, such as space scheduling,
navigation of robots, geographic information systems, computer vision,
planification. Several qualitative approaches have been proposed to
represent spatial and temporal entities and their relations. These
approaches consider the qualitative aspects of the relations only,
disregarding any quantitative measurement. In some applications, e.g.
multi-agent systems, spatial or temporal information concerning a set of
objects may be conflicting. In this talk I will highlight the problem of
merging spatial or temporal qualitative constraint networks (QCNs). I
will present a rational merging procedure which, starting from a set of
possibly conflicting QCNs, returns a non-empty set of spatial or
temporal information representing the result of the merging. It is based
on translations of QCNs into propositional formulas and takes advantage
of propositional merging operators.
Speaker:
Lionel Daniel Title:
Paraconsistent probabilistic reasoning: application to
high-level data fusion in multimodal biometrics
Abstract:
In multimodal biometrics, data of several biometric sensors
(classifiers) must be aggregated to decide on the authenticity of an
individual. Such data are usually high-level since most commercial
biometric classifiers only provide information at score, ranking, or
decision levels. I suggest to fuse these high-level data by applying a
theory that deals with contradictory information: paraconsistent
probabilistic reasoning. Such a theory can also be applied to problems
from voting theory.
Keywords: decision making, paraconsistency, common sense, voting
theory.
Speaker:
Pietro Baroni and Massimiliano Giacomin (University of Brescia) Title:
Attacks to attacks in abstract argumentation
Abstract:
Encompassing attacks to attacks is a significant conceptual extension
of Dung's abstract argumentation framework motivated by modelling
needs in various contexts including reasoning about preferences,
coalition formation, meta-argumentation.
Several alternative approaches to encompassing attacks to attacks in
abstract argumentation have been recently proposed in the literature.
By reviewing and comparing these proposals, the talk aims at
presenting a general perspective and technical analysis on the main
conceptual and formal issues related to encompassing attacks to
attacks in abstract argumentation.
Speaker:
Thomas Ågotnes (University of Bergen) Title:
Group Announcements: Logic and Games
Abstract:
Public announcement logic is used to reason about the epistemic pre-
and post-conditions of actions in the form of public announcements. In
the first part of the talk I will present Group announcement logic
(GAL), an extension of public announcement logic with constructs (well
known from coalition logic) of the form Speaker:
Nick Tinnemeier (Utrecht University) Title:
Programming Norm Change
Abstract:
Computational frameworks using normative concepts (e.g. obligations and prohibitions)
have been widely adopted for regulating the observable behavior of (software) agents.
To adequately deal with the unpredictable and dynamic environments these normative frameworks
are typically deployed in, mechanisms for modifying the norms at runtime are crucial.
In this talk I present the syntax and operational semantics of generic programming
constructs to facilitate runtime norm modification, allowing a programmer to specify
when and how the norms may be changed by external agents or by the normative framework.
In particular, I present rule-based constructs for runtime modification
of the norms (conditional obligations and prohibitions), the detached
obligations and prohibitions they instantiate (norm instances), and a mechanism for
automatically updating the instances when their underlying norms change.
Speaker:
Eric Pacuit (University of Tilburg) Title:
Revising Intentions and Beliefs
Abstract:
While there is an extensive literature developing logical models
to reason about informational attitudes (e.g. belief, knowledge, certainty)
in a dynamic environment, other mental states have received relatively less
attention. (A notable exception here is work on logics of preferences and
preference change.) However, this is changing with recent articles
developing a theory of intention revision (see, for example, two recent
articles: Towards a Theory of Intention Revision by van der Hoek, Jamroga
and Wooldridge and A Logic of Intention and Attempt by Lorini and Herzig).
These papers take as a starting point logical frameworks derived from Cohen
and Levesque's seminal paper aimed at formalizing Bratman's planning theory
of intention. In this talk, I will discuss a number of recent dynamic
logics of intention and beliefs. In the process we will reexamine a
number of foundational issues surrounding so-called BDI-logics.
Speaker:
Pablo Noriega (Artificial Intelligence Research Institute) Title:
mWater as a normative MAS
Abstract:
The "mWater" system is a demonstrator of the Spanish "Agreement Technologies" (AT) project http://www.agreement-technologies.org/ currently in construction. The problem domain is the normative aspects that affect water demand in a basin. In particular, the trading of water usage rights and the conflicts associated with trading and exploitation of those rights. We are currently designing the ground institutional framework where exchange of rights and conflicts may take place. The objective is to establish and implement the constitutive conventions (and the ground domain ontology) of a normative MAS. The purpose of this MAS is to provide AT researchers with a convenient virtual environment, where several activities may be regulated in different ways, conducive to a rich interplay between theoretical and engineering issues associated with agreement topics. My presentation would be a description of the framework and an exploration of normative issues that might be interesting to address.
Speaker:
Francesca Toni (Imperial College) Title:
Combining statistics and arguments to compute trust
Abstract:
We propose a method for constructing Dempster-Shafer
belief functions modeling the trust of a given agent (the
evaluator) in another (the target) by combining statistical
information concerning the past behaviour of the target and
arguments concerning the target's expected behaviour. These
arguments are built from current and past contracts between
evaluator and target. We prove that our method extends a
standard computational method for trust that relies upon
statistical information only. We observe experimentally that
the two methods have identical predictive performance when
the evaluator is highly "cautious", but our method gives a
significant increase when the evaluator is not or is only
moderately "cautious". Finally, we observe experimentally that
target agents are more motivated to honour contracts when
evaluated using our model of trust than when trust is
computed on a purely statistical basis.
Speaker:
Andreas Herzig (IRIT) Title:
The dynamic logic of propositional control
Abstract:
Along the lines of Coalition Logic of Propositional Control (CLPC), we
propose a dynamic logic of propositional control DLPC. It extends
classical propositional logic by a variety of modal operators of
assignment, and modal operators of transfer of control over a
propositional variable. We also present an epistemic extension. We
establish the relationship of these logics with the existing CLPC and
with its extension by control transfer DCLPC. We study their complexity
and their proof theory.
Speaker:
Jan Broersen (Utrecht University) Title:
A stit-logic analysis of intentional action
Abstract:
We study intentional action in stit-logic. The formal logic study of
intentional action appears to be new, since most logical studies of
intention concern intention as a static mental state. We model an
intended action as an action that possibly deviates from the actual
action conducted by an agent. First, an actual action may deviate from
an intended action because the agent is not able to carry out the
intended action, and the actual action is used as a means to achieve the
goal of the intended action. This explains differences such as the one
between the actions `murder' and `manslaughter', and problems like the
`dentist's' scenario of Cohen and Levesque. Second, an actual action may
deviate from an intended action because the agent's environment behaves
unexpectedly and the result of an action is not the one envisaged by the
agent. So, the action is unexpectedly unsuccessful. We show how to deal
with the distinction between successful and non-successful action by
weakening the notion of `knowingly doing' to its `belief' equivalent.
Finally, we briefly consider weakening the epistemic attitude towards
action performance even further by discussing opportunities to model the
notion of `attempt'.
Speaker:
Hans van Ditmarsch (University of Sevilla) Title:
Security protocols using card deals Abstract:
In the mid-19th century, Thomas Kirkman and Jacob Steiner gave birth to what later became known as design theory, a subdiscipline of combinatorial mathematics. Tools and techniques from that area can be used to design unconditionally secure (communicative) protocols. The epistemic logician can also focus on the epistemic properties of such protocols, or reformulate their specifications (such as security requirements) in such terms. Individual, common and distributed knowledge all play a role. Following original contributions from the 1980s onward by Winkler, Fischer, Wright and others, we focus on the case of computationally unlimited agents using card deals. Given various agents or players, two among them (sender and receiver, say, but note that they both send and receive) may wish to communicate a secret. We present some results for the restricted case where secrets concern card ownership, and for the general case where any secret bit can be exchanged by means of such card deals.
Speaker:
Emiliano Lorini (IRIT) Title:
Epistemic Games in Modal Logic: from individual rationality to social preferences Abstract:
I present in this work a sound and complete modal logic called EDLA
(Epistemic Dynamic Logic of Agency) integrating the concepts of joint
action, preference and knowledge and enabling to reason about epistemic
games in strategic form. I provide complexity results for EDLA. In the
second part of the paper, I study in EDLA the epistemic and rationality
conditions of some classical solution concepts like Nash equilibrium and
Iterated Deletion of Strictly Dominated Strategies (IDSDS). Moreover, I
combine EDLA with Dynamic Epistemic Logic (DEL) in order to model
epistemic game dynamics. In the conclusion, I show how EDLA can used to
model social preferences and group/team reasoning.
About the speaker:
Emiliano Lorini has received a PhD in Cognitive Sciences from the
University of Siena (2007). In 2007-2009, he was a post-doctoral
researcher at the Institut de Recherche en Informatique de Toulouse
(IRIT), France. He is actually a CNRS researcher at the university of
Toulouse and at IRIT. He is working on several topics in the area of
logic, multi-agent systems and cognitive sciences: theory of intentional
action, theory of emotions, logical foundations of game theory, deontic
logic, theory of institutions and organizations, theory of collective
action and collective intentionality.
Speaker:
Tony Hunter (University College London ) Title:
Computational Models of Argumentation for Richer Logics
Abstract:
Abstract argumentation provides a natural starting point for modelling
argumentation. In abstract argumentation, a graph is used to represent a
constellation of arguments and the conflict between them. Each argument
is represented by a node, and the attack of one argument on another is
represented by a directed arc. Proposals by Phan Minh Dung and others
then give principled ways for determining which arguments are acceptable
based on the structure of the graph. However, abstract argumentation
assumes the existence of such graphs and does not provide means for
generating them. To address this, Henry Prakken and others, have shown
how logic can be used to generate arguments and to identify conflict
between arguments. However, most proposals for using logic, assume a
simple defeasible logic. Yet, elsewhere in artificial intelligence,
there is the need to use richer logics such as classical logics,
description logics, modal logics, temporal logics, and probabilistic
logics. In this talk, we consider a framework for harnessing richer
logics in computational models of argument.
Speaker:
Alexandru Baltag (Oxford University) Title:
Iterated Belief-Revision with Higher-Level Information:
from doxastic cycles to learning the truth
Abstract:
I investigate and compare the long term-behavior of various belief-revision "methods" (or "belief-revision policies", or "belief upgrades", as they are sometimes called), under learning of higher-level doxastic information. By "learning" I mean iterated belief revision with new truthful information. By "higher-level doxastic information" I mean sentences that may refer to the agent's own beliefs, or to her belief-revision plans (her conditional beliefs), even if they also convey factual information. "The long-term behavior" refers to whether or not the agent's beliefs stabilize eventually, converging to a fixed point, or keep changing forever, in infinite cycles. If they do stabilize, we are interested to find natural conditions ensuring they converge to true beliefs (or even to true and complete beliefs). About the speaker: Speaker:
Juan Antonio Rodriguez (IIIA, Spain) Title:
On the emergence of social conventions in multi-agent complex networks
Abstract:
Distributed mechanisms that regulate the behavior of autonomous
agents in open multi-agent systems (MAS) are
of high interest since we cannot employ centralized approaches
relying on global knowledge. In actual-world societies,
the balance between personal and social interests is
self-regulated through social conventions that emerge in a
decentralized manner. As such, a computational mechanism
that allows to engineer the emergence of social conventions
in MAS can become a highly promising tool to endow open
MAS with self-regulating capabilities. To this end we propose
a computational self-adapting mechanism that facilitates
agents to distributively evolve their social behavior
to reach the best social conventions. Our approach borrows
from the social contagion phenomenon: social conventions
are akin to infectious diseases that spread themselves
through members of the society. We will
experimentally show that our mechanism helps a MAS to
regulate itself by searching and establishing (better) social
conventions on a wide range of interaction topologies and
dynamic environments. Moreover, we will also show that the
mechanism can cope with large convention spaces. Finally,
we will turn our attention to the robust emergence of social conventions.
Current computational models for the emergence of conventions
assume that there is no uncertainty regarding
the information exchanged between agents. However, this
assumption is too strong when unreliable information might be exchanged
because agents
may: (i) deliberately lie; (ii) make wrong assessments or
misjudgements; or (iii) communicate through noisy channels.
Hence, within these settings conventions may fail to emerge.
We will show how to extend our mechanism
for the emergence of conventions to help agents reach global
consensus on conventions despite information uncertainty.
The extension is based on allowing agents to self-protect
against unreliable information.
Speaker:
Guillaume Aucher (ILIAS) Title:
BMS revisited
Abstract:
In knowledge representation, the insight of the BMS logical framework
(proposed by Baltag, Moss and Solecki) is to representhow an event is
perceived by several agents very similarly to the way one represents how
a static situation is perceived by them: by means of a Kripke model.
There are however some differences between the definitions of an epistemic
model (representing the static situation) and an event model. In this talk
I will restore the symmetry. Unlike any other logical framework, this one
allows to express statements about ongoing events, which are very useful
in knowledge representation. It also models the fact that our perception
of events (and not only of the static situation) can also be updated due
to other events. I axiomatize it and prove its decidability. Finally,
I show that it embeds the BMS one (if one adds common belief operators).
About the speaker:
Guillaume Aucher is one of the ICR team members.
Speaker:
Angela Bovo (ONERA Toulouse) Title:
Validity of a speech reported by several consecutive sources
Abstract:
We are trying to determine the degree of trust we can give to a
speech that has been reported by several consecutive sources, in a
multi-agent, non-cooperative context. We propose a modal logic modeling for
reported speech. We then define its properties of validity and invalidity,
and the criteria for validity. In addition, we will show how this work
relates to the Agent Communication Languages (ACLs). This work has possible
applications in intelligence.
About the speaker:
Angela Bovo is a master student in artificial
intelligence. She studied in the University of Toulouse 3 and in the
engineering school Ecole Nationale Superieure de l'Aeronautique et de
l'Espace. She is currently working in the ONERA (Toulouse) for her master
internship. She is currently working on language modelling, epistemic and
doxastic logic as well as non cooperative agent communication languages.
Angela would like to work on cognitive sciences and possibly spiking neural
networks in the future.
Speaker:
Alexander Artikis (Demokritos, Athens) Title:
Dynamic Protocols for Open Agent Systems
Abstract:
Multi-agent systems where the members are developed by parties with
competing interests, and where there is no access to a member's internal
state, are often classified as 'open'. The specification of protocols
for open agent systems of this sort is largely seen as a design-time
activity. Moreover, there is no support for run-time specification
modification. About the Speaker:
Alexander Artikis is a research associate at the National Centre for
Scientific Research "Demokritos", in Athens, Greece, and a visiting
researcher at Imperial College London. He was awarded his PhD in
Computing (Multi-Agent Systems) from Imperial College London in 2003.
His research interests lie in the areas of temporal representation and
reasoning, and distributed artificial intelligence. He has been
publishing papers in related conferences and journals, such as the
Artificial Intelligence Journal, and the ACM Transactions on
Computational Logic.
Speaker:
Piotr Kazmierczak, University of Warsaw Title:
On tableau systems for some modal logics
Abstract:
This paper is an attempt to present and compare two different
tableau systems for modal logic K. First we present general
philosophical ideas behind theorem proving and modal logics, then we
briefly describe tableau for PC, and further tableaux for modal logics.
Tableau systems are indeterminate, but with some additional regulations
they can be turned into decision procedures—we show how is it achieved.
We also present a somewhat innovative way to construct a labelled
tableau for K, and at the end we show implementations of theorem provers
for PC and K written in SWI Prolog. What is yet to be presented in the
paper (not yet written) is an efficienct comparison between two
different tableaux for K. It will be a strictly practical comparison
(like a benchmark), showing strenghts and weaknesses of these systems.
Speaker:
Xavier Parent (ILIAS, ICR) Title:
Remedial interchange, contrary-to-duty obligation, and commutation Abstract:
The talk will focus on the relation between deontic logic and the study of conversational interactions. Special attention will be given to the notion of remedial interchange introduced by E. Goffman into the literature on conversational interactions. This notion appears to be close to the one of contrary-to-duty (reparational) obligation, which deontic logicians have been studying in its own right. I will investigate the question of whether some of the aspects of conversational interactions can fruitfully be described using formal tools originally developed in the study of iterated belief change. I will adapt the latter tools to deontic logic, and attempt an account of remedial interchange (and, more generally, contrary-to-duty reasoning) in terms of commutation. This account brings the dynamics of obligations to the fore.
About the speaker:
Xavier Parent is a research associate in the Individual and Collective Reasoning (ICR) group at the University of Luxembourg. His current research interests are focused upon both fundamental and applied research related to deontic logic, with a special focus on dyadic deontic logic and the like. He obtained a Ph.D in philosophy with his thesis ``Non-monotonic Logics and Modes of Argumentation. The case of conditional obligation". Prior to joining the ICR group in Luxembourg, he was a research associate at the Computer Science Department of the King's College London, UK.
Speaker:
Matteo Baldoni (University of Turino) Title:
Choice, Interoperability, and Conformance in Interaction Protocols and Service Choreographies
(a joint work with C. Baroglio, A. K. Chopra, N. Desai, V. Patti, M. P. Singh) Abstract:
Many real-world applications of multiagent systems require
independently designed (heterogeneous) and operated (autonomous)
agents to interoperate. We consider agents who offer
business services and collaborate in interesting business
service engagements. We formalize notions of
interoperability and conformance, which appropriately
support agent heterogeneity and autonomy. With respect to autonomy,
our approach considers the choices that each agent has, and how
their choices are coordinated so that at any time one agent
leads and its counterpart follows, but with initiative
fluidly shifting among the participants. With respect to
heterogeneity, we characterize the variations in the agents'
designs, and show how an agent may conform to a specification or
substitute for another agent. Our approach addresses a challenging
problem with multiparty interactions that existing approaches
cannot solve. Further, we introduce a set of edit operations
by which to modify an agent design so as to ensure its conformance
with others.
About the Speaker:
Matteo Baldoni is an associate professor at the Department of Computer Science
of the University of Torino since 2006 where he took his Ph.D. in Computer
Science in May 1998. From July 1999 through September 2005 he has been
researcher at the Department of Computer Science of the University of Torino.
He has a background in computational logic, modal and non-monotonic extensions
of logic programming, multimodal logics, reasoning by actions and change.
His current research interests include issues in communication protocol design
and implementation, conformance and interoperability for agents and web
services, agent programming languages, web services and service oriented
architecture, personalization by reasoning in the semantic web, e-learning.
Speaker:
Hans Rott (University of Regensburg) Title:
The Ramsey Test for Conditionals and Iterated Theory Change Abstract:
According to the Ramsey Test, conditionals reflect changes of theories (or beliefs): A>B is accepted in T iff B is accepted in the minimal revision of T necessary to accommodate A. More than 20 years ago, the Ramsey test has come under heavy attack. A series of impossibility theorems ("triviality theorems") seemed to show that given standard models of theory change, the Ramsey test cannot serve as a viable analysis of conditionals. Other authors have come to its defence, arguing that it is rather the standard AGM-type model of theory change that is mistaken. In this talk I argue that an overly postulational approach to the semantics of (nested) conditionals should be avoided and that one should instead turn to an analysis in terms of constructive models of (iterated) theory change.
A crucial question is whether it is possible to use the Ramsey Test for the interpretation of conditionals and still respect the Preservation Condition according to which the original theory T should be fully retained after a revision by information that is consistent with T. Among the four most natural models for iterated belief change, I identify two solutions that indeed allow us to combine the Ramsey test with Preservation in languages containing only non-nested conditionals of the form A>B. These solutions, however, violate Preservation for nested conditionals of the form A>(B>C). I argue that by looking at the constructve models, we can understand why it has been wrong to expect that Preservation holds in languages containing nested conditionals.
Speaker:
Dov Gabbay (King's College / University of Luxembourg) Title:
Matrix Abduction with Applications to Argumentation Theory and Paradoxes of Voting Abstract
We motivate and introduce a new method of abduction: Matrix Abduction.
Given a matrix A with entries in {0, 1}, we allow for one or more blank squares
in the matrix, say ai,j = ?. The method allows us to decide whether
to declare ai,j = 0 or ai,j = 1 or ai,j = ?
undecided. This algorithmic method is then applied to modelling several legal
and practical reasoning situations including the Talmudic rule of Kal-Vachomer.
We show that this new method can also be applied to the analysis of paradoxes
in voting and judgement aggregation. In fact we have here a general method for
executing non-deductive inferences. The method also offers a non deductive
realisation of argumentation networks, where arguments are abduction matrices
and the form of attack is matrix expansion.
About the Speaker:
Dov Gabbay is one of the godfathers of the field of formal logic.
Speaker:
Martin Caminada and Gabriella Pigozzi (ILIAS) Title:
On Judgement Aggregation in Abstract Argumentation Abstract
We present a paper that we have recently written for the special issue on computational social choice of the Journal of Autonomous Agents and Multi-Agent systems (JAAMAS). The topic is applying judgement aggregation to abstract argumentation
Speaker:
Catherine Pelachaud (CNRS, TELECOM ParisTech) Title:
Virtual humanoid listener Abstract
Communicating with virtual humanoids imply they should have the
capability to speak and to listen. In the past years we have
concentrated our effort on creating a virtual humanoid able to
communicate not only through speech but also through its nonverbal
behaviours. It can display facial expression of emotion, it can gaze at
a person, it can describe an object or show a point in space, etc.
Lately we have started to work on a listener model. In a conversation
not only the speaker but also the listener are active participants. Both
interactants send verbal and nonverbal messages. Trough facial
expression, head movement, or even gaze, the listener indicates what are
its attitudes toward the speaker’s say, if it likes or dislikes, agrees
or disagrees, understands or not, etc. In this talk we will present
on-going work on the creation of a virtual humanoid able to communicate
with human users. In particular we will describe our model of a virtual
listener able to react to speaker’s speech and to indicate its mental
state in real-time. About the speaker
Catherine Pelachaud is a Director of Research at CNRS in the laboratory
LTCI, TELECOM ParisTech.
In 1991 she obtained her PhD in Computer Graphics at the University of Pennsylvania.
During 1993 and 1994 she was postdoc with a National Science Foundation grant,
involved in the production of a system which automatically generates and animates
conversations between multiple human-like agents with appropriate and synchronized
speech, intonation, facial expressions, and hand gestures. Her current reserach
topics are:
Speaker:
Martin Rehak (Department of Cybernetics, Czech Technical University, Prague) Title:
CAMNEP: Collaborative Reduction of False Positives in Network Intrusion Detection Abstract:
Current network behavior analysis methods based on
anomaly detection approaches suffer from comparatively higher error rate
and low performance. We propose a framework system which addresses these
issues by (i) using hardware-accelerated probes to collect unsampled
NetFlow/IPFIX data from gigabit-speed network links and (ii) combining
several anomaly detection algorithms by means of collective trust
modeling, a multi-agent data fusion method. The data acquired on the
network is preprocessed in the collector database and then passed to
several anomaly detection methods to obtain several independent anomaly
opinions for each flow. Each of these methods uses a distinct set of
aggregate traffic features to determine the anomaly of each flow, which
is determined by comparing the observed flows with a method-specific
traffic prediction and/or a set of rules. The anomaly data is passed to
several trust models to aggregate the current anomalies with past
experience. Each of the trust models represents the flows in a high
dimensional feature space, and progressively builds flow clusters which
represent typical traffic behaviors. The clusters are labeled with the
typical anomaly of the flow in the cluster, and this trustfulness (i.e.
the anomaly aggregated over a long term) is used to evaluate the current
flows, instead of the immediate anomaly determined for this flow. The
trustfulness values provided by trust models based on different features
are integrated into the final result and compared with a
dynamically-defined threshold. Our experiments performed on real
university and WAN networks suggest that the framework significantly
improves the error rate while being computationally efficient, and is
able to process the network speeds up to 1Gbps in online mode. Depending
on the specific network, it can remove up to 95% of false positives when
compared to individual anomaly detection methods, and up to 75% of false
positives when compared to simple average of flow anomalies. About the speaker:
Martin Rehak holds engineering degree from Ecole Centrale Paris. He is currently researcher at Agent Technology Group of the Gerstner laboratory and in the same time pursues his PhD studies at the Department of Cybernetics of the Czech Technical University. His current research interests are security, network intrusion detection, trust modeling and task allocation in adversarial environments. Speaker:
Davide Grossi (ILIAS) Title:
Correspondences in the theory of aggregation Abstract
In this talk I will investigate some interrelationships between the social-theoretic problems of preference and judgment aggregation from the perspective of formal logic. On the one hand, preference aggregation will be shown to be equivalent to the aggregation of some special types of judgments (logical formulae). On the other hand, the judgment aggregation problem will be proven equivalent to the aggregation problem of specific types of preferences. As a result, a detailed map of aggregation problems is obtained which highlights differences and similarities between the two research fields of preference and judgment aggregation, which allows the cross import of impossibility results between them, and which makes a systematization of the two fields possible. About the speaker
Davide Grossi has been a member of our ICR research group in 2008 and will soon start
to work at the ILLC in Amsterdam. Speaker: Juliana Bueno-Soler (UNICAMP, Brazil) Title: Anodic and cathodic modalities: managing negatons in modal logic Abstract:
I will discuss the role of negaton in the domain of anodic logics (modal logics withouth
negation) and cathodic logics (paraconsistent modal logics with some kind of negation).
Motivations for studying such logics as connected to some deontic paradoxes will be given.
Some difficulties about completeness for anodic logics will be emphasized,
and completeness results, as well as an incompleteness result, will be sketched.
This is a work in progress, and questions, problems and research lines wil be also
assessed. About the speaker:
Juliana Bueno-Soler is a visiting PhD student from the Department of Philosophy and CLE
at UNICAMP, Brazil.
Speaker: Jonathan Ben-Naim (IRIT) Abstract:
In many multi-agent systems, the user has to decide whether he
(or she) sufficiently trusts a certain agent to achieve a certain goal.
To help users to make such decisions, an increasing number of trust
systems have been developed. By trust system, we mean a system that
gathers information about an agent and evaluates its trustworthiness from
this information. The aim of the present paper is to develop new trust
systems that overcome limitations of existing ones. This is a challenging
problem that raises questions such as: how trustworthiness may be
represented, and from which information it may be estimated? We assume
that a set of grades describing the past performances of the agent is
given. With this common basis, two approaches are proposed. In the first
one, the aim is to construct an interval that summarizes the grades. Such
an interval gives a good account of the trustworthiness of the agent. We
establish axioms that should be satisfied by summarizing methods, devise
a particular method based on pulling, and check that it satisfies the
axioms, which provides theoretical justifications for it. In the second
approach, which is more briefly presented, a level of trust as the
certainty that a future grade will be good, and a level of distrust as
the fear that a future grade may be bad, are computed on the basis of the
past grades. This approach is based on possibility theory and provides,
thanks to the two levels, another view of trustworthiness, as well as
summarizing intervals. About the speaker:
Jonathan Ben-Naim has received a PhD in Computer Science from the
University of Aix-Marseille (2006). In 2006-2007, he was a post-doctoral
researcher at the University of Luxembourg. Since October 2007, he is a
CNRS researcher at the university of Toulouse. He is currently working on
the development and the axiomatization of trust and reputation systems.
Speaker: Walter Carnelli (State University of Campinas, Brazil) Title: Possible-Translations Semantics and Logics of Formal Inconsistency Abstract:
Besides its great importance for mathematical reasoning,
standard logic, sometimes called "classical logic", cannot be
seriously accepted as a basis for rationality. Indeed, rationally
acceptable statements are not coincident with true statements,
and contradictions in reasoning sometimes play a most important
role. So, for instance, only contradictory allegations can make a
judge decide whether there is any false statement around--there is
no other reason why, in justice, people are interviewed in
separate. Much to the contrary to what some philosophers
maintain, in informal reasoning the use of contradictions is
inherent and contradictions may contain precious information. It
is a task of logic to offer a suitable formal model for the
perfectly licit act of reasoning under contradictions, and
paraconsistent logic accomplishes this. In particular, the wide
family of "ogics of formal inconsistency" (LFI's) achieve this in
a remarkably natural and elegant way. The possible-translations
semantics (PTS's) were devised in 1990 in order to offer a
palatable interpretation to some non-classical logics, and are
very well adapted to LFI's. PTS's depart from the notion of
translations as morphisms between logics (maps preserving their
consequence relations). If translations are thought as different
"world views", the concept of possible-translations semantics
offer a way to interpret a given logic L as the combination of
all possible "world views", technically viewed as an appropriate
set of translations of the formulas of L into a class of
"simpler" logics with known semantic characterization. In this
way LFI's give a very natural account of understanding the
phenomenon of a sentence and its negation being both true.
However, PTS's can be given to non-paraconsistent logics as well,
and also serve as a powerful tool to decompose logics in the
spirit of the program of combining logics. Several examples will
be discussed and some research directions will be suggested. About the speaker:
Walter Carnielli is professor of the Department
of Philosophy and of the Centre for Logic, Epistemology and the
History of Science at the University of Campinas, Brazil. He has
a Master degree in Algebra (1978) and a Ph.D. in Logic (1982)
from the University of Campinas, with post-doc positions at the
University of California, Berkeley and in Germany (Münster and
Bonn) as Alexander von Humboldt grantee. Carnielli's research is
focused on foundations of non-classical logics and applications
to common-sense reasoning and computation. He is presently
visiting the Individual and Collective Reasoning group at CSC-
University of Luxembourg on an FNR research grant. Speaker: Mehdi Dastani
(Utrecht Univerity) Title: Normative Multi-Agent Programs and Their Logics Abstract:
Multi-agent systems are viewed as consisting of individual agents whose
behaviors are regulated by an organization artefact. This paper presents
a simplified version of a programming language that is designed to
implement norm-based artefacts. Such artefacts are specified in terms of
norms being enforced by monitoring, regimenting and sanctioning
mechanisms. The syntax and operational semantics of the programming
language are introduced and discussed. A logic is presented that can be
used to specify and verify properties of programs developed in this
language. About the speaker:
Mehdi Dastani is a lecturer in computer science at the Utrecht
University. He has received his master degrees in computer science
(1991) and philosophy (1992) from the University of Amsterdam and
obtained his PhD degree (1998) at the institute for logic, language and
computation, University of Amsterdam. He is currently working in the
area of multi-agent systems, multi-agent programming, and agent logics
for the last ten years and has published many papers on these subjects.
Speaker: Odinaldo Rodrigues
(King's College) Title: A multi-level framework for information change Abstract:
In belief revision, it is often the case that preference and
consistency are intertwined concepts. The most general view
is that of an input formula which is preferred to an old belief set
when together they are inconsistent (in the classical logic sense).
This is not always adequate for several reasons and many variations
of belief revision techniques have been proposed to address specific
issues, e.g., iteration of the revision process.
About the speaker:
Odinaldo Rodrigues has a BSc in Informatics from the University of
Fortaleza, a MSc in Systems Engineering and Computation from the Federal
University of Rio and a PhD in Computing from Imperial College London.
He is currently a member of the Group of Logic, Language and Computation
in King's College London. His research concentrates on the formalisation
of common-sense reasoning, theory change and Artificial Intelligence
techniques and their applications to computer science. Speaker: Maria Biryukov
(ILIAS, MINE) Title: Language Classification of Personal Names with Application to DBLP Abstract:
We propose a new perspective for the data analysis in digital libraries,
bibliographic and other databases containing personal names. Knowing
language/cultural background of a person can be beneficial in many
applications, however this information is often not present explicitly
in the databases. We present in this talk a statistical tool for the
automatic language detection of personal names. Our system does not
require a dictionary of names for training and handles 14 different
languages so far. General purpose corpora for all Western European,
Chinese, Japanese and Turkish languages are used in order to build
simple statistical models of the languages. The system is fine tuned
to achieve precision and recall above 90% for many languages. On an
example of a bibliographical database DBLP we show how our system can
be used in tasks such as data cleaning and discovery of trends. In the
second part of the talk we demonstrate how the co-author network, which
is built from the bibliographic records, an be incorporated into the
process of personal name language classification. Testing the model on
the DBLP data set shows that the extension of the language classification
process with the co-author network may help to refine the classification
obtained from the author names considered independently. It may also lead
to the discovery of dependencies between the elements of the co-author
network, or participation of authors in scientific communities.
About the speaker:
Maria has graduated in Master in Artificial Intelligence program from
K.U. Leuven in September 2004. In 2005-2006 Maria was working in the
University of Namur where she was involved in the project aiming at
development and implementation of a domain independent tool for creation
of question answering systems. In January 2007 Maria joined the University
of Luxembourg as a Ph.D student and is working in the MINE group under
the supervision of Prof. Christoph Schommer.
Speaker: Thierry Mamer Title: Improving the use of ILP for Biological Grammar Acquisition Abstract:
This talk will present some of the recent work done in my PhD studies.
In the first part of the talk, some basic principles of Inductive Logic
Programming (ILP), Biological Grammar Learning and Minimum Description
Length will be introduced. The second part will identify a shortcoming
of a standard positive-only clause evaluation function within the
context of learning biological grammars and explain how we propose to
overcome it. We will describe L-modification, a modification to this
evaluation function such that the lengths of individual examples in the
training data are considered. We will show, among other things, that
using L-modification to learn from a protein family called Neuropeptide
Precursors results in induced grammars that have a better performance
than that achieved when using the standard positive-only clause
evaluation function.
About the speaker:
Thierry is a research student at the Robert Gordon
University in Aberdeen, Scotland. He has graduated with an honours
degree in Computer Science (Artificial Intelligence) in 2005. He is
currently conducting his last experiments and hopes to start writing up
his PhD thesis soon. His current interests lie in the area of Machine
Learning, Inductive Logic Programming, Bioinformatics, and loosely in
Data Compression.
Speaker: Sascha Kaufmann (CSC) Title: Making Web Portals Convivial Abstract:
In this talk, we want to motivate the idea of conviviality in web
portals and argue that a convivial social being deeply depends on the
implicit and explicit co-operation and co-laboration of natural users
inside a community. Our belief is that an individual conviviality can
benefit from the wisdom of the crowd, meaning that a continuously
and dynamic understanding of the user's behaviour can heavily influences
the inidividual well-being.
For this, we introduce the system CUBA, which stands for
"Conviviality and User Behavior Analysis". The purpose of CUBA is to
find novel ways to support users during their visits while discovering their
interests. In this respect, CUBA comes up with certain
recommendations and suggestions, which are partially based on a
common behavior of participants in general. For example, concepts
like time, space, and diverse user-based actions are taken into
account. The talk closes with a report about the current state of the
project.
About the speaker:
Sascha Kaufmann received his diploma in Computer Science from the JW
Goethe-University in Frankfurt/Main. He is now a doctoral student at
the MINE Group, ILIAS Laboratory.
Speaker: Yining Wu (ILIAS) Title: Towards an Argument Game for Stable Semantics Abstract:
We present a discussion game for argumentation under stable semantics.
Our work is inspired by Vreeswijk and Prakken, who have defined a similar
game for preferred semantics. We restate Vreeswijk and Prakken’s work
using the approach of argument labellings and then show how it can be
adjusted for stable semantics. The nature of the resulting argument
game is somewhat unusual, since stable semantics does not satisfy
the property of relevance. The current presentation is
a try-out for a talk at the CMNA workshop (Computational Models of Natural
Argument) at the end of July.
About the speaker:
Yining Wu has obtained a Master's degree of Computational Logic at the Technische
Universität Dresden and is currently doing a PhD on Argumentation and Trust
at the ILIAS group of the University of Luxembourg. Speaker: Manfred Jaeger
(Aalborg University) Title: Probabilistic modeling and learning in relational domains Abstract:
In the last few years we have seen the emergence of the new field of
"Statistical Relational Learning", also called "Probabilistic Logic
Learning", or "Relational Data Mining". The plethora of labels results from the
fact that this field is a confluence of several quite distinct strands of research: one
line of research is the combination of probabilistic graphical models with more abstract,
logic-based, knowledge representation languages. A second line of research
contributing to the new field are probabilistic extensions of inductive logic programming
techniques. Finally (and perhaps most significantly), probabilistic logic learning joins
together these AI traditions with those areas in machine learning that are concerned
with learning from structured data (graphs, sequences, relational databases, ...). In this talk I will first introduce Probabilistic Logic Models as a formal semantic
basis for a wide range of models and representation languages used in statistical relational
learning, especially the language of Relational Bayesian Networks, which will also be
described. Finally, I will present recent developments on parameter learning for
Relational Bayesian Networks, and on relational feature discovery using Type Extension
Trees. About the speaker:
Manfred Jaeger obtained a Diploma in Mathematics from Freiburg
University in 1991, and a PhD in Computer Science from the University
Saarbrücken in 1995. From 1995 to 2003 he was research associate at the
Max-Planck Institute for Computer Science in Saarbrücken, and also spent
time as postdoctoral researcher at Stanford University, Helsinki
University, and Freiburg University. In 2003 he joined the Machine Intelligence
group at Aalborg University as Associate Professor. His research centers around
the integration of probabilistic and logical reasoning in Artificial
Intelligence and Machine Learning.
Speaker: Jean-François Raskin
(Université Libre de Bruxelles) Title: An introduction to games played on graphs Abstract:
In this talk, I will review the fundamental notions underlying the
notion of games played on a graph. I will consider both turn-based and
concurrent games, different notions of strategies, winning conditions,
and the foundations for algorithms to solve those games.
About the speaker:
Jean-François Raskin was born in Belgium, in 1972. He received his
master and Ph.D. degrees in computer science from the Université de
Namur, Belgium, in june 1995 and april 1999, respectively. After long
research stays at the University of California at Berkeley, Max-Planck
Institute for Computer Science (Saarbrucken), and ENS Paris, he is now
Associate Professor (chargé de cours) at the computer science
department of the Université Libre de Bruxelles (ULB), Belgium. His
research interests are the formal methods for the verification of
concurrent, real-time, and hybrid systems. At the ULB, he teaches
subjects in theoretical computer science : automatic proofs and proofs
of programs, logic in computer science, computability and complexity,
and analysis of hybrid systems. He is also the secretary of the
Belgian F.N.R.S. contact group on Theoretical Computer Science.
Speaker: Henry Prakken
(University of Utrecht / University of Groningen, the Netherlands) Title: Integrating Different Modes of Reasoning Abstract:
Many reasoning problems involve subproblems of different kinds, which can be solved in different ways. In this talk an abstract formalism will be presented in which any set of specific problem solving methods satisfying some weak conditions can be combined. The formalism makes it possible to formally express dependencies between different subproblems, to define an overall solution on the basis of solutions to subproblems, and, most importantly, to manage alternative, incompatible solutions to (sub)problems. The formalism will be illustrated with a legal example that combines standard first-order logic, Bayesian probability theory and two versions of default logic.
About the speaker:
Henry Prakken is a lecturer in the Intelligent Systems group of the computer science department at Utrecht University, and professor of Law and ICT at the law faculty of the University of Groningen. He has master degrees in law (1985) and philosophy (1988) from the University of Groningen. In 1993 he obtained his PhD degree at the Free University Amsterdam with a thesis titled Logical Tools for Modelling Legal Argument. Prakken's research concerns logical foundations of common-sense reasoning and argumentation, and the application of Artificial Intelligence and advanced IT to legal reasoning, dispute resolution, group decision making and negotiation.
Speaker: Martin Mozina (University of Ljubljana, Slovenia) Title: Integration of Machine Learning and Argumentation Abstract:
Machine learning is concerned with development of algorithms for
extracting implicit knowledge from data. As these algorithms need to
select among several alternative explanations of data, the resulting
models often seem incomprehensible to domain experts. On the other hand,
since argumentation studies and formalises common-sense reasoning and
can be therefore used to represent experts' knowledge in a natural way,
we can expect that their integration would yield benefits in both areas.
During my talk I will introduce basics of machine learning and point out
several possible combinations of machine learning and argumentation. The
focus will be on recently developed approach Argument Based Machine
Learning (ABML), which uses arguments provided by experts to guide
machine learning algorithms towards comprehensible explanations of data.
About the speaker:
Martin Mozina has received a BSc degree in computer science at the
Faculty of computer and information science in Ljubljana in year 2003,
and is since a PhD student at the Artificial Intelligence Laboratory. In
years 2004-2007 he worked as a reasearcher on european project ASPIC
(Argumentation Service Platform with Integrated Components) and
currently he works now on X-Media project (Large scale knowledge sharing
and reuse across media). His research mainly includes machine learning,
the use of argumentation in machine learning algorithms, visualization
of learned models, and programs for automatic tutoring.
Speaker: Nikos Vlassis
(Dept. of Production Engineering and Management
Technical University of Crete, Greece) Title: Distributed Decision Making for Large Teams of Agents Abstract:
We address the problem of optimal action selection and
coordination of a large team of collaborative agents. We view the
problem as a combinatorial optimization problem where we need to
maximize a payoff function that is additively decomposed over a graph.
We first review a dynamic programming approach that finds the optimal
solution but has exponential worst-case time complexity. We then
describe an approximate message-passing algorithm for action
selection, similar to belief propagation for Bayesian networks, that
exhibits a very good runtime/performance trade-off. We discuss
extensions to distributed stochastic optimal control, and outline
possible applications.
About the speaker:
Nikos Vlassis received a diploma in Electrical and Computer
Engineering in 1993, and a PhD in 1998, both from the National
Technical University of Athens, Greece. In 1999 he was visiting
researcher at the Electro-Technical Laboratory in Tsukuba, Japan. From
2000 until 2006 he held an Assistant Professor position at the
University of Amsterdam, The Netherlands. Since 2007 he holds an
Assistant Professor position at the Technical University of Crete,
Greece. He has published one monograph on multiagent systems and
several papers in the fields of robotics and machine learning. His
current research interests include robotics, multiagent systems,
machine learning, and stochastic optimal control.
Speaker: Andreas Herzig Title: Grounding power on actions and mental attitudes Abstract:
The main objective of this work is to develop a logical framework called
IAL (Intentional Agency Logic) in which we can reason about mental states
of agents, action occurrences, agentive and group powers. IAL will be
exploited for a formal analysis of different forms of power such as an
agent's power of achieving a certain result, an agent's power to do a
certain action and an agent's power over another agent.
Speaker: Régis Riveret Title: Argumentation: Game Theory as Heuristics. Abstract:
Over the years many dialogue games for argumentation have been proposed to shed
light on questions such as which conclusions are (defeasibly) justified, or how
procedures for debate and conflict resolution should be structured to arrive at
a fair and just outcome. An aspect of debates which has not yet received much
attention is the common sense observation that the outcome does not solely
depend on the premises of a case, but also on the strategies that parties in a
dispute actually adopt. The focus is on Speaker: Carlos Ribeiro. Title: Research on Multi-agent Systems and Complex Social Networks
at the Technological Institute of Aeronautics. Abstract:
In this talk I will first present some aspects of the Technological Institute of
Aeronautics (ITA) in the broad context of the Air Industry. ITA is the main
centre for research and education on Aerospace, Aeronautics and Air Force issues
in Brazil. Founded in 1950, it is one of the main responsibles for the important
role the brazilian aeronautics industry has today, with its main
company—Embraer—having produced more than 4,100 aircrafts which
operate in 69 countries. Speaker: Mozhgan Tavakolifard Title: A Distributed and Statistical based Trust and Reputation
Management Framework Abstract:
The rapidly changing environments of the internet suffer from problems such a fragile trustworthiness of millions active entities on the internet, e.g. human and mobile agent. This problem is nontrivial as more and more commercial transactions get carried out over the internet. Therefore, devising an effective way for verifying the trustworthiness entity in such complex environments is essential. To this end, Ntropi framework was designed to facilitate the exchange of trust and reputation in information/business environments. The trust mechanism plays a key role in security of multi-agent systems. Also the trust establishment is nontrivial, since the traditional and social means of trust cannot be applied directly to virtual settings of these environments. Because, in many cases the involved parties have not interacted before. Therefore, the reputation techniques must be used to estimate the good qualities and behaviors in online markets and communities, and also sanction the poor qualities and bad behaviors of this. The Ntropi has classified the trust into direct (explicit) and recommended classes. The direct class is divided into five agent-based sections called "very trustworthy", "trustworthy", "moderate", "untrustworthy", and "very untrustworthy". But the recommended trustworthy is derived from word-of-mouth (e.g., opinions), which is called reputation, and can be translated to direct or regular trusts. This paper presents an automated and autonomous trust system using Bayesian inference and improved Dirichlet distribution. Also a re-trusting mechanism (forgiveness) is devised and incorporated into Ntropi framework. This simulation results indicate the effectiveness of our model and the percentage of improvements. Speaker: Denis Zampunieris Location: Room E012 Title: e-Learning and Proactive Computing Abstract:
Learning Management Systems (LMS) or e-learning platforms are dedicated
software tools intended to offer a virtual educational and/or training
environment online. Although there are already a large number of
functions for a variety of different users acting specific roles in
these environments, current LMS are fundamentally limited tools. Indeed,
they are only reactive software developed like classical, user-action
oriented software. These tools wait for an instruction, most probably
given through a graphical user interface, and then react to the user
request. Speaker: Eugen Staab Location: Room A02 Title: Excusableness for Failing Agents or False Negatives in Trust Assessment Abstract:
To estimate how much an agent can be trusted, its trustworthiness needs to be assessed. Usually, poor performance of an agent leads to a decrease of trust in that agent. This is not always reasonable. If the environment interferes with the performance, the agent is possibly not to blame for the failure. We examine which failures can be called excusable and hence must not be seen as bad performances. Knowledge about these failures makes assessments of trustworthiness more accurate. In order to approach a formal definition of excusableness, we introduce a generic formalism for describing environments of Multi-Agent Systems. This formalism provides a basis for the definition of environmental interference. We identify the remaining criteria for excusableness and give a formal definition for it. Our analysis reveals that environmental interference and a strong commitment of the performing agent do not suffice to make a failure excusable. Speaker: Paul Harrenstein Location: Room A02 Title: Dominance in Social Choice and Coalitional Game Theory Abstract:
We consider dominance relations for social choice as based on the
pairwise majority rule on the one hand and cooperative games with
non-transferable utility (coalitional NTU games) on the other. As these
dominance relations may fail to be transitive and even contain cycles,
the notion of maximality becomes untenable as an analytical tool. Both
in social choice theory and cooperative game theory, a number of
concepts have been proposed to take over the role of maximality in the
absence of transitivity. In 1953 McGarvey showed that any irreflexive
and anti-symmetric relation can be obtained by the majority rule. In
this paper, we address the analogous issue for finite NTU games. We find
any irreflexive relation over a finite set can be obtained as the
dominance relation of some ordinary, monotonic, and simple NTU
coalitional game. We also show that any dominance relation can be
induced by a non-cooperative game via beta-effectivity. Furthermore,
we obtain a partial result for the case in which alpha-effectivity is
used and consider the formal interrelationships between Smith sets,
Schwartz sets, stable sets and the core in finite NTU games. Speaker: Girma Berhe Title: Autonomic management for distributed systems: Example of DIET Abstract:
Today's increasingly complex architectures and distributed computing
infrastructures require highly skilled IT professionals to install,
configure, operate, tune and maintain them. This impedes effective and
efficient execution of business processes and the delivery of services
that relay on the IT infrastructure. In particular, IT management has
become too complex and costly. Moreover, the fact that management tasks
are performed by humans leads to many configuration errors and low
reactivity. Autonomic computing helps to address these problems by
providing self-managing capabilities to IT systems. In this presentation,
the foucs is on the use of JADE, a middleware for self-management of
distributed software environments. Speaker: Sanjay Modgil Title: Reasoning about Preferences in Argumentation Frameworks Abstract:
A Dung argumentation framework consists of a set of arguments
related by a conflict based binary attack relation. A 'calculus of opposition'
is then applied to determine the justified or 'winning' arguments under
different extensional semantics. The framework abstracts from the underlying
logic in which the arguments and attack relation are defined. Dung's seminal
theory of argumentation has thus become established as a general framework
for non-monotonic reasoning, and, more generally, reasoning in the presence
of conflict. Speaker: Kittichai Lavangnanda Location: Room C02 Title: Introduction to Evolutionary Computation and an application in knowledge discovery (a data mining program SARG) Abstract:
Evolutionary Computation is one of the most popular techniques used in a sub-field of Artificial Intelligence (AI) known as Soft Computing or Computational Intelligence. Evolutionary Computation are used to offer solutions to problems where no known conventional methods or algorithms can guarantee optimal/best solution. Knowledge Discovery (or Data Mining) is a broad term which is used to describe techniques in discovering useful patterns hidden in a given dataset. One such techniques is to generate rules which discover these patterns by relating or associating one set of attributes to another hidden in the dataset. These set of rules are commonly known as Association Rules. The problem of generating efficient association rules can seen as search problem since many different sets of rules are possible from a given set of instances. As the application of evolutionary computation in searching is well studied, it is possible to utilize evolutionary computation in mining for efficient association rules. Speaker: Maria Fasli Location: Room B02 Title: Accounting for Social Order in Multi-agent Systems Abstract:
As agents are required to inhabit and operate in increasingly complex
environments and interact with other agents as elements of larger systems, some
means of regulating their behaviour to avoid disruption and to ensure smooth
performance, fairness and stability is needed. To this end, theoretical research
and in particular agent theories need to address issues such as stable group
activity, regulation of behaviour and elements that contribute to social order
in multi-agent systems. In this talk we will describe a formal framework that
accounts for social order within a multi-agent system based on organizational
and normative concepts. The fundamental building blocks of multi-agent systems
are social agents whose structure can be formally characterized in terms of
roles and relationships between them including authority relations. Social
agents are bound together via commitments and different types of social agents
may be bound by commitments in different ways. Agents are autonomous and may
decide to deviate from prescribed behaviour and violate their commitments and
obligations, but as a consequence they may have to face the sanctions as a
result of the other agents exercising their rights. Speaker: Richard Booth (Joint work with T. Meyer) Location: Room B02 Title: On the dynamics of total preorders—Revising abstract
interval orders Abstract:
Total preorders (tpos) are often used in belief revision to encode an agent's strategy for revising its belief set in response to new information. Thus the problem of tpo-revision is of critical importance to the problem of iterated belief revision. In a previouswork (with T. Meyer and K-S. Wong) we provided a useful framework for revising tpos which adds extra structure to guide the revision of the initial tpo. However, one shortcoming of this framework is that ith andles *single-step* tpo-revision only. In this talk I will briefly review this framework, before giving a way to extend it to consider *double-step* tpo-revision. This extension employs a new way to represent the structure required to revise a tpo, based on *abstract interval orders*. Speaker: Mario Paolucci Title: Repage—Reputation and Image for Partner Selection in
Simple Markets Abstract:
Reputation is a fundamental instrument of partner selection. Developed within the domain of electronic auctions, reputation technology isbeing been imported into other applications, from social networks to institutional evaluation. Its impact on trust enforcement isuncontroversial and its management is of primary concern for entrepreneurs and other economic operators. Speaker: Marcello D'Agostino (joint work with Corrado Sinigaglia) Title: Forecasting Accuracy and Subjective Probability Abstract:
De Finetti's favourite justification of the probability laws, within his "subjectivist" account of probability theory, was in terms of "scoring rules". These are rules that are often employed in evaluating the accuracy of probabilistic forecasters and measuring their predictive success. De Finetti showed that if a specific scoring rule is adopted, the so-called Brier's rule, consisting in taking the mean squared error over a time series of predictions, then the score of a forecaster whose predictions are in accordance with the probabilistic laws dominates that of any forecaster whose predictions violate them. If this has to be read as a subjectivist justification of the probability rules, a natural question to ask is: why Brier's rule? Why couldn't we measure forecasting accuracy by means of any other reasonable rule, such as the one based on the mean absolute error? Several attempts have been made in the literature to characterize Brier's rule as the only proper scoring rule satisfying some general, more or less compelling, properties. In this talk we take a different approach. We embed the scoring problem into the general problem of measuring the distance between two times series of predictions and present a set of natural properties that a distance function between such time series should satisfy. We then show that these properties uniquely determine a metric which, coincides with Brier's scoring rule in the special case in which one of the two series is generated by an "infallible" forecaster. We then argue that, in this way, De Finetti's subjectivist approach to the justification of the probabilistic laws can be accomplished without appealing to the, somewhat misleading and inconclusive, arguments based on the elicitation problem and on the notion of "proper scoring rule" which have so far been the main, if not exclusive, concern of the literature. Speaker: Wojtek Jamroga Title: A Logic for Reasoning about Rational Agents (joint work with
Nils Bulling) Abstract:
Game theory identifies a number of solution concepts (e.g., Nash equilibrium, undominated strategies, Pareto optimality) that can be used to define rationality of players. Then, the notion of rationality can be employed to discard "less sensible" behavior of players, and determine what should happen had the game been played by ideal agents. Game-theoretical solution concepts have been also characterized invarious modal logics, including dynamic logic, dynamic epistemic logic, and alternating-time temporal logic (ATL). On the other hand, modal logics of time, action and strategies are a natural choice when one wants to reason about behavior of arbitrary agents. In this work, we try to bridge these two concepts, and propose a logic for reasoning about the behavior of agents under rationality assumptions. In particular, we do not want to commit to any particular notion of rationality; instead, we prefer to allow for "plugging in" rationality assumptions in a flexible way. Speaker: Stijn Vanderlooy Title: The ROC Isometrics approach. Abstract:
A wide variety of state-of-the-art machine-learning classifiers areavailable to be used in practice. Nevertheless, only few classifiers areemployed in application domains with high misclassification costs, e.g.,medical diagnosis and law enforcement. Speaker: Jerome Lang. Title: Sequential voting rules and multiple elections paradoxes (joint work with Lirong Xia and Mingsheng Ying). Abstract:
Multiple election paradoxes arise when voting separately on eachissue from a set of related issues results in an obviouslyundesirable outcome. Several authors have argued that a sufficient condition for avoiding multiple election paradoxes is the assumption that voters have separable preferences. We show that this extremely demanding restriction can be relaxed into the much more reasonable one: there exists a linear order x1 > ... > xp on the set of issues such that for each voter, every issue xi is preferentially independent of xi+1, ..., xp given x1, ..., xi-1. This leads us to define a family of sequential voting rules, defined as the sequential composition of local voting rules. These rules relate to the setting of conditional preference networks (CP-nets) recently developed in the Artificial Intelligence literature. We study in detail how these sequential rules inherit, or do not inherit, the properties of their local components. We focus on the case of multiple referenda, corresponding to multiple elections with binary issues. Speakers: Foued Melakessou and Zdzislaw Suchanecki. Title: On The Road Towards The Comprehension Of The Internet Traffic
Behavior: Simulation And Analysis Of An End-To-End Connection With NS-2. Abstract:
This contribution is attempting to address the problem of understanding how different aspects of networks—physical topology and routes on that topology—along with packet arrival models lead to congestion and other observed network characteristics as its fractal and periodic behavior. We reveal topology and routing effects on data transmissions between two routers linked by a connection path in a well-defined network environment. Our statistical approach is based on log-normal distributions. We show that the fractal behavior of a network node traffic can be viewed as a consequence of the topology and routingeffects. This work is based on random simulations performed by the network simulator ns-2. We have shown that the longer the connection path, the more log-normal is the inter-arrival time distribution at the destination node. Moreover a spectrum analysis has been performed in order to emphasize the traffic periodic behavior rising from the most used transfer protocol TCP/Reno. Speaker: Glenn Lawyer. Title: Subtypes of controls and schizophrenia patients based on brain
cortical thickness. Abstract:
Given the broad range of symptoms and known brain morphological disturbances in patients with schizophrenia, it is a priori possible that subtypes of the disease could be identified in localized cortical thickness measures. Recent advances in magnetic resonance imaging allow invivo measurement of cortical thickness at each vertex in a 1mm grid covering the entire cortex. Measurements were made on 106 patients and 96 controls. At each vertex, the number of clusters of individuals best explaining the data was determined. This was done for the patient group,the control group, and the two groups combined. It was found that the patients were primarily homogeneous with regard to cortical thickness. Exceptions were found in regions where the controls were also heterogeneous. This implies that these regions of heterogeneity are common to humanity. When the method was applied to the combined data, it largely agreed with findings of group difference previously established by significance testing. Speaker: Marcin Seredynski. Title: Evolution of a Strategy Driven Behavior in Ad Hoc Networks. Abstract:
We propose a strategy driven approach which aims at enforcing cooperation between network participants. Each node is using a strategy that defines conditions under which packets are being forwarded. Such strategy is based on the notion of trust and activity of the source node of the packet. These way network participants are enforced to forward packets and to reduce the amount of time of being in a sleep mode. To evaluate strategies we use a new game theory based model of an ad hoc network. This model also includes a simple reputation collection and trust evaluation mechanisms. A geneticalgorithm (GA) is applied to find good strategies. Speaker: Bram Roth. Title: How to preserve deterrence whilst abstaining from
strategies? Abstract:
Deterrence is a relation that holds between strategies of players involvedin a game. Informally one strategy is deterrent vis-a-vis another if it canreasonably be played and there are reasonable alternatives to the deterredstrategy. More formally the reasonableness of strategies is captured by a notioncalled playability. Three systematic procedures are discussed for solving gamesof deterrence by abstaining from strategies, in order to find the playability ofeach strategy. The conditions are explored under which these procedures arevalid and their intuitive interpretations are provided. Abstaining from what iscalled a harmless strategy, for instance, is shown to be valid only if theharmless strategy does not happen to be the only safe strategy available to aplayer. An efficient algorithm for solving games is proposed on the basis of theiterative application of the procedures, and ways are suggested to explore themultiplicity of playability solutions to games of deterrence.Contact and Getting there
Future talks
Overview
Agent Programming in GOAL
Classification and Strategical Issues of Argumentation Games on Structured Argumentation Frameworks
Title TBA
Algorithmic Aspects of Phylogenetic NetworksWednesday, May 9, 2012, 11:00, room A14
Monday, June 18, 2012, 16:00, room E112
Past talks
Overview
Hypernets: a formalism to model and reason about mobility
Exploitation of Parallel Heterogeneous Architectures for multimedia processing
How to Achieve and How to Verify Norm Compliance of Resource-Bounded Agents?
Bounded Model Checking Linear Time and Knowledge Using Decision Diagrams
Tableau Method and NEXPTIME-Completeness of DEL-Sequents
Models of Manipulation on Aggregation of Binary Evaluations
Late Work Scheduling Problems
The Power of the Hexagon
Partial-Observation Stochastic Games: How to Win when Belief Fails
A Logical Account of Lying
Eunomos, a legal document management system based on legislative
XML and ontologies
A New Approach for Preference-Based Argumentation Frameworks
A Liberal Impossibility of Abstract Argumentation
Epistemic, Probabilistic ATL* with an Application to Security
Turning competition into cooperation and cooperation into competition
Logics of agents with small models
The Logic of Campaigning
Complexity of Judgment Aggregation
Concentration inequalities for mean field particle models
The Carneades Argumentation System
Mindful Evolution
Proving Interpolation in Description Logics Using Mosaic and Axiom Instantiation Techniques
Intuitionistic logic, elementary rules, classical logic
Proto-probability functions
Optimal Coalition Structure in Humanoid Robots
On the Complexity of Verifying Agents With and Without Memory: A Comparison
Neurosymbolic Cognitive Computation
Strategic Executions of Choreographed Timed Normative Multi-Agent
Systems
Preference Reasoning
Information, Multimodality and Signals
A Logical Framework for Capturing the Dynamics of Information and
Abilities of Players in Multi-Player Games (joint work with
Peter Hawke)
An Integrated Possibilistic Framework for Goal Generation
in Cognitive Agents
On strategy composition and game composition
Dependence Theory via Game Theory
Merging Qualitative Constraint Networks Using Propositional Logic
Paraconsistent probabilistic reasoning: application to
high-level data fusion in multimodal biometrics
Attacks to attacks in abstract argumentation
Wednesday, May 2, 2012, 16:00, room E112
Friday, April 20, 2012, 14:00, room E112
Monday, March 26, 2012, 16:00, room E112
Monday, March 12, 2012, 16:00, room E112
Monday, February 27, 2012, 16:00, room E112
Wednesday, February 1, 2012, 14:00, Auditorium Tavenas (Limpertsberg)
Wednesday, January 25, 2012, 14:00, room E012
Monday, January 23, 2012, 16:00, room E112
Thursday, Decemember 8, 2011, 16:00, room A02 (joint ILIAS/SRM seminar)
Monday, September 19, 2011, 14:00, room E112
Friday, July 1, 2011, 11:00, room E012
Monday, May 23, 2011, 16:00, room E112
Thursday, April 28, 2011, 10:00, room E112
Monday, April 4, 2011, 16:00, room E112
Monday, March 14, 2011, 17:00, room E112
2) are there alternative ways to build up cooperative interactions from
strategic ones?Friday, March 11, 2011, 15:30, room Paul Feidert
Friday, March 11, 2011, 16:30, room Paul Feidert
Monday, February 14, 2011, 16:00, room E112
Wednesday, February 23, 2011, 17:30, room Paul Feidert
Wednesday January 12, 2011, 16:00, room E112
Carneades will be demonstrated using a prototype application for helping software developers to analyse Open Source licensing issues, which was developed in the European Qualipso project. The presentation will focus on the underlying computational model of argument.
Monday November 22, 2010, 16:00, room E012
Wednesday October 27 (16:00, room E012)
Thursday October 21 (16:00, room E012)
Monday October 18 (17:00, room E112)
Wednesday September 29, 2010, 16:00, room E012
Wednesday September 8, 2010 (17:30, room E012)
Monday July 26 (10:00)
Thursday July 1 (14:15, room E112)
Thursday July 1 (15:15, room E112)
Thursday June 24 (16:00, room E112)
Monday June 21, 2010 (16:00, room E112)
Thursday June 17 (16:30, room A02)
Monday June 14 (16:00, room E112)
Thursday June 10 (16:00, room C02)
Monday May 31, 2010 (14:00, room E112)
Thursday May 27 (16:00, room E112)
Thursday May 20 (16:00, Salle des Conseils)
Thursday April 29 (16:00, room A02)
Monday April 19, 2010 (14:00, room E112)
Thursday April 1 (16:00, room A02)
I will also discuss a recent paper on ``joint revision of belief and
intention" (with Yoav Shoham and Thomas Icard) where we present a formal
semantical model to capture action, belief and intention, based on the
“database perspective†of (Logical Theories of Intention and the Database
Perspective, Journal of Philosophical Logic, 2009, by Yoav Shoham). We
provide postulates for belief and intention revision, and state a
representation theorem relating our postulates to the formal model. Our
belief postulates are in the spirit of the AGM theory; the intention
postulates stand in rough correspondence with the belief postulates.
Friday March 26 (11:00, Salle des Conseils)
Thursday March 11 (16:00, Salle du Conseil)
Wednesday March 10 (16:00, room to be announced)
Thursday February 25 (16:00, room A02)
Thursday January 28 (16:00, room B02)
Thursday January 21 (17:30, room A02)
Thursday November 19 (16:00, Salle du Conseil)
Thursday November 5 (16:00, room C02)
The methods I consider are the following: conditioning; the "conservative upgrade" or "minimal revision" of Boutilier; a variant of minimal revision (re)formulated in terms of Spohn ordinals; lexicographic (or "radical") upgrade (initially proposed, and rejected, by Spohn, then generalized by Nayak, and justified by Glaister based on symmetry reasons, and by Baltag and Smets as a special case of the "Action-Priority Update Rule"); Spohn's ordinal analogue of Jeffrey conditioning; Darwiche and Pearl's natural modification of Spohn's method (called the "ratched method" by Kelly); Goldszmidt and Pearl's method etc.
My results are in general negative, with two exceptions: when starting with an initial finite Spohn model, the only methods that guarantee convergence of (simple) beliefs are conditioning and lexicographic upgrade (as well as its Nayak generalization). For these two types of upgrades, one can easily find natural conditions ensuring that a stream of upgrades converges to true and complete beliefs (the condition is to have a "maximally informative upgrade stream"). The positive result for lexicographic upgrades is non-trivial. I also give characterizations of the fixed points reached eventually (if reached), of the 2-cycles, 3-cycles etc.
In the end, I relate this discussion to Learning Theory, to the Surprise Examination Puzzle and (time-permitting) to the issue of belief merge via persuasive communication within a group, with applications to rationality announcements in games of perfect information.
This talk is based on joint work with Sonja Smets.
EMPLOYMENT AND DEGREES:
1989: Masters in Mathematics, University of Bucharest.
1990-1992: Journalist.
1992-1993: Researcher at the Institute of Mathematics of the Romanian Academy.
1993-1998: Fulbright research fellowship at Indiana University.
1998: PhD in Mathematics, Indiana University, under the supervision of Jon Barwise and Larry Moss.
1998-2001: Post-doctoral Researcher, at CWI and ILLC (Amsterdam).
2001-present: University Lecturer, Oxford University Computing Laboratory.
WORK AND INTERESTS:
modal logic, dynamic logic, epistemic logic, temporal logic;
belief revision, models for multi-agent information flow;
quantum logic and quantum information flow;
coalgebras, non-well-founded sets, Universal Set Theory, models for self-reference, circularity and fixed-points;
rationality and action in Game Theory;
Epistemology, Philosophy of Information and Philosophy of Science.
Thursday October 22 (16:00, Salle des Conseils)
Thursday September 24 (16:00, room C02)
Wednesday September 16 (16:00, room B02)
Thursday July 30 (16:00, room A02)
Due to environmental, social, or other conditions, however, it is often
required to revise the specification during the protocol execution.
To address this requirement, we present an infrastructure for 'dynamic'
protocol specifications, that is, specifications that may be modified at
run-time by agents. The infrastructure consists of well-defined
procedures for proposing a modification of the 'rules of the game' as
well as decision-making over and enactment of proposed modifications.
We evaluate proposals for rule modification by modelling dynamic
specifications as metric spaces. Furthermore, we constrain the enactment
of proposals that do not meet the evaluation criteria.
Tuesday July 28 (14:00, room C02)
Thursday June 18 (16:00, room A02)
Wednesday April 29 (16:00, room A16)
Thursday April 2 (16:00, room A02)
Thursday March 12 (16:00, room A02)
Thursday March 5 (16:00, room A02)
Thursday January 15 (16:00, room A02)
Catherine Pelachaud is member of the Ph.D. committee of Patrice Caire.
Monday December 8 (14:00, room B02)
Prior to his current position, Martin was member of the Mobile Communication Operations team of Schlumberger Smartcards (now Axalto), where he was working on definition, design and integration of novel location-based and other value added services for major European and African operators. Before obtaining his degree, he was a freelance contractor to diverse Czech and French companies, including General Electric Medical Systems. Martin is a 2005 McKinsey Scholar, and a member of AAMAS’06-08 program committee. In 2006, he was a visiting researcher with National Institute of Informatics, Tokyo. Thursday December 4 (16:00, room B02)
Wednesday October 22 (16:00, room B02)
Thursday October 16 (16:00, room B02)
Thursday October 9 (16:00, room B02)
Thursday July 31 (16:00, room A02)
Thursday July 31 (11:00, room B02)
Thursday July 24 (16:00, room A02)
Monday July 21 (11:00, room A02)
Thursday July 10 (16:00, room A02)
Monday July 7 (11:20, room A02)
Thursday July 3 (16:00, room A02)
Monday May 26 (14:00, room A02)
Thursday May 22 (16:00, Salle du Conseil)
Thursday April 10 (10:30, Salle du Conseil)
Thursday March 20 (16:00, E012)
Thursday January 24 (16:00)
Wednesday December 19 (16:00)
adjudication
debates in which two
participants aim to persuade each other to adopt a certain opinion and, a
neutral third party (for example, a judge) must decide at the end whether to
accept the statements that the opposing parties have made during the debate.
In this presentation, the problem studied is how to use game theory to
determine optimal strategies in dialogue games for argumentation. To do so, the
main notions of Prakken's abstract argument games are interpreted in game
theory, and optimal strategies are defined accordingly. Then, a specification
of the expected utility of a strategy is provided by combining the probability
of success of arguments with their associated costs and benefits. The
presentation will also discusses some related work and, suggest future
investigations.Thursday December 13 (16:00)
The talk will then switch to the research carried out at the Artificial
Intelligence and Robotics Group at ITA, particularly in the topics on
Multi-Agent Systems and Complex Social Networks. On Multi-Agent Systems,
I will present our research on the design of overlay networks for incident
(failures and attacks) detection in a network model. The purpose of this
research is to devise mechanisms for topology control that considers na
autonomous negotiation process based on a consensus among nodes in a
hierarchical structure. Still in the context of Multi-Agent Systems, we present
a method for pairwise combination of partial robotic maps based on
paraconsistent logics which can be adapted for a consensus-based mobile robotic
network. Finally, we explore the issue of Social Network Analysis regarding
both its technological and theoretical aspects: a project on fraud and
irregularity detection for the Brazilian Inland Revenue and the Brazilian Air
Force) and the analysis of metrics for evaluating small-world properties in
large social networks.Friday December 7 (11:30)
22nd of November
Students using these online systems could imagine and hope for more help
and assistance tools, especially because those users are often
inexperienced ones and expect some guidelines (what to do and how to do
it) from the system instead of a static user interface. LMS should tend
to offer to these students some personal, immediate and appropriate
support based on an intelligent analysis of their (lack of) actions,
like teachers do in classrooms.
Moreover, certain users like e-tutors have to peruse lots of data in
order to try to efficiently manage other users' needs and expect some
clues (where to search and what to look for) from the system instead of
a passive database.
We introduce a new kind of Learning Management Systems: Proactive LMS,
designed to improve their users' online interactions by providing
programmable, automatic and continuous analyses of users (inter-)
actions augmented with appropriate actions initiated by the LMS itself.
Proactive systems [D. Tennenhouse, "Proactive Computing", Communications
of the ACM, 43 (5), 2000, pp. 43–50] adhere to two premises: working on
behalf of, or pro, the user, and acting on their own initiative, without
user's explicit command. Proactive behaviors are intended to cause
changes, rather than just to react to changes. This is a major change
from interactive computing, in which we lock a system into operating at
exactly the same frequency as humans do.
Our proactive LMS can, for example, automatically and continuously help
and take care of e-users with respect to previously defined procedures
rules, and even flag other users, like an e-tutor, if something "wrong"
is detected in their behaviors; it can also automatically verify that
awaited behaviors of e-users have been carried out, and it can react if
these actions did not happen.8th of November
18th of October
11th of October
The main principle is to wrap legacy systems(or software elements) in
components in order to provide a uniform management interface, thus
allowing the deployment of distributed applications and reconfigure them
autonomously as required. A particular use case and experiments in using
JADE will be presented.4th of October
To determine a unique set of justified arguments invariably requires
that a preference relation on arguments is available. However, preference
information is often itself defeasible, conflicting and so subject to
argumentation based reasoning. In this talk I will describe my work on
extending Dung's framework to include arguments that claim preferences
between other arguments. Specifically, the framework is extended to include
a second attack relation such that an argument that claims a preference
between two other arguments, attacks the binary attack between these two
conflicting arguments. I will describe how the the justified arguments of
an extended framework are evaluated under the full range of Dung's
extensional semantics, and discuss how the core results for Dung frameworks
scale up to extended frameworks. I will therefore propose that the extended
semantics provides a general a framework for non-monotonic reasoning
formalisms that accommodate defeasible reasoning about as well as with
preference information. To substantiate this proposal I will show how
existing reasoning formalisms can be formalised and extended in the
framework, and will illustrate with examples demonstrating agent
reasoning over beliefs goals and actions.13th of September
In this presentation, Evolutionary Computation and its applications will be introduced in order to realize its potential. A program known as Self-adjusting Association Rules Generator (SARG) is described. SARG is a data mining program which can generate association rules for classification. It is an improvement of the data mining program called Genetic Programming for Inductive learning (GPIL). It has been tested on several benchmark data sets available in the public domain. Comparison between GPIL and SARG revealed that SARG achieved better performance and was able to classify these datasets with higher accuracy. The presentation will also discusses relevant aspects of SARG and suggest directions for future work.6th of September
23th of August
July 13, 2007
In this talk, I will introduce Repage, a computational system that adopts a cognitive theory of reputation, based on theoretical research performed at LABSS in the course of several years. One of the main proposals is a fundamental difference between image (agents' believed evaluation of a target) and reputation (circulating evaluation, without reference to the evaluation source), which suggests a way out from the paradox of sociality, i.e. the trade-off between agents' autonomy and their need to adapt to social environment. On one hand, agents are autonomous if they select partners based on their social evaluations (images). On the other, they need to update evaluations by taking into account others'. Hence, social evaluations must circulate and be represented as "reported evaluations" (reputation), before and in order for agents to decide whether to accept them or not.
To represent this level of cognitive detail in artificial agents' design, there is a need for a specialised subsystem, which we have developed for the public domain.
After presenting the system, I will shortly report upon simulation-based studies on the role of reputation as a more tolerant form of social capital than familiarity networks. Whereas the latter exclude non-trustworthy partners, reputation is a more inclusive mechanism upon which larger and more dynamic networks are constructed.In the simulation, we model the spreading of information in a simple market with the presence of liars and the possibility of retaliation. While fear of retaliation inhibits the spreading of image, the detached character of reputation can be a cause of inaccuracy; The two forces could balance indifferent settings.
Final remarks and ideas for future works will conclude the paper, with special attention on the choice of developing the system algorithmically and not within a formal logic. I will also shorty present the current lines of development in the "eRep—Social Knowledge for e-Governance" project.July 12, 2007
June 28, 2007
June 14, 2007
In this talk I will outline the ROC isometrics approach. The approachprovides a framework to extend classifiers such that their performancecan be set by the user prior to classification. Hence, classifiersbecome reliable. I will show that the ROC isometrics approach ispractically useful and does not have strong assumptions. An extensiveempirical evaluation of the approach will verify the analysis.
From the analysis and experimental evaluation we may conclude that theROC isometrics approach results in classifiers that can safely beapplied in any domain.
May 3, 2007
March 22, 2007
March 6, 2007
February 22, 2007
February 8, 2007