IJCAI-03 Tutorials
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The IJCAI tutorials program for 2003 features one invited tutorial and 20 four-hour tutorials, each covering a concentrated technical topic of current or emerging interest. Tutorials will be presented by experienced researchers and practicioners who are experts in the correspondig subject area. A separate registration fee applies to each four-hour tutorial. The invited tutorial is open to all registrants.
Sunday, August 10
Personalized recommendation of products, documents, and collaborators has become an important way of meeting user needs in commerce, information provision, and community services, whether on the web, through mobile interfaces, or through traditional desktop interfaces. This tutorial first reviews the types of personalized recommendation that are being used commercially and in research systems. It then systematically presents and compares the underlying AI techniques, including recent variants and extensions of collaborative filtering, demographic and case-based approaches, decision-theoretic methods, methods based on the implicit or explicit elicitation of preferences, and various types of hybrid method. The techniques are discussed within a general integrative framework that allows participants to see how techniques can be selected and combined for particular applications. The presentation refers to concrete examples involving either commercially deployed systems or influential research prototypes. Special attention is paid to the implications of the practical aspects of deployment contexts--for example, issues of privacy and transparency--for the choice of AI recommendation techniques. The tutorial presupposes a general knowledge of AI. Some previous familiarity with issues of personalized recommendation is desirable but not essential.
Stochastic search algorithms have been shown to outperform
their deterministic counterparts in a number of interesting application
domains. They are becoming increasingly important and popular for solving
computationally hard combinatorial problems from various domains of AI
and Operations Research, such as planning, scheduling, constraint satisfaction,
satisfiability, or combinatorial auctions. In this tutorial we will introduce
stochastic search algorithms and characterise them as instances of the
more general class of Las Vegas algorithms. We will cover local search
algorithms, including stochastic hill-climbing, simulated annealing, tabu
search, evolutionary algorithms, and ant colony optimization, as well
as randomised systematic search algorithms. For exemplifying these algorithms,
we will mainly use the Satisfiability Problem in Propositional Logic (SAT)
and the Travelling Salesperson Problem (TSP), which both play a central
role in the design, implementation, and analysis of algorithmic ideas.
We will also address the empirical analysis of Las Vegas algorithms and
present case studies demonstrating the successful application of stochastic
search algorithms to various problem domains. Prerequisite knowledge:
The attendees should have an interest in computationally hard combinatorial
problems. Basic knowledge in standard AI search problems as well as a
basic knowledge of search methods would be an advantage but are not necessary
prerequisites.
With the explosion of networking and affordable robotics, multiagent learning has become a hot research topic, combining the mature fields of machine learning and multiagent systems. The problem of learning a goal-oriented course of action in the presence of other goal-oriented agents raises new problems for both learning and multiagent systems. Complicating the learning problem is that when other agents are adapting, traditional machine learning assumptions like stationarity are violated. This tutorial will explain the unique challenges that are being addressed and the importance of this still-emerging field. A large focus will be on the introduction of critical game-theoretic concepts that underlie much of the recent work. This will be followed by an overview of the current progress, detailing the varied approaches and algorithms. A common set of problems and examples will be carried throughout the tutorial to provide continuity and a uniform understanding of the various techniques' strengths and weaknesses. There will also be a discussion of the future issues and open problems that still remain. No background in game theoretic concepts will be assumed. A basic understanding of Markov decision processes and reinforcement learning would be helpful, although the most relevant concepts will be briefly reviewed.
This tutorial provides an introduction to the principles and practice of behavior-based mobile robot programming for individual robots and for multi-robot teams. We will survey the inspiration and motivation for behavior-based autonomous robot systems, the unique challenges in this field and the wide range of solutions developed thus far. In addition to learning about the applications of behavior-based techniques for programming individual robots, attendees will learn about the theoretical and algorithmic aspects of behavior-based multi-robot systems, including communication, coordination and cooperation. This tutorial is targeted at non-specialists who have a general background in AI or robotics. Robotics experience is not assumed.
Ontologies constitute the foundation for many intelligent
systems today. They have gained popularity for very different needs of
groups like the World Wide Web community, the database community and the
machine learning community. They are applied to applications and infrastructures
like the Semantic Web, information extraction, e-Commerce, or E-Learning
applications. The goal of this tutorial is to acquaint the reader with
the basics of ontologies that are used for applications: It is the objective of this tutorial to communicate to the audience a comprehensive picture in order to understand the role of ontologies in future information systems. Thus, AI researchers will learn about how their work (e.g. learning, knowledge acquisition) may contribute to the overall task of ontology-based systems. Furthermore, practitioners will learn how ontologies may help to solve some of their problems with AI's ontologies.
This tutorial will be devoted to discussing different immunological mechanisms and their relation to information processing and problem solving. The natural immune system is an adaptive learning system which is highly distributive in nature. It employs several alternative and complementary mechanisms for defense against foreign pathogens. The tutorial will cover an overview and the latest advances in this emerging field -- the artificial immune systems, which include computational algorithms based on immunological principles:
This tutorial will be interesting to the audience who would like to explore new and innovative techniques as problem solvers. The participants will gain an understanding of the field, be able to appreciate the application potential of this new technique, and gain better insights about how to engineer massively parallel adaptive complex systems.
The tutorial reviews genetic algorithms and related models of genetic and evolutionary computation. Markov models are used to understand stochastic heuristic search methods. Walsh Analysis is used as a tool for exactly characterizing problem complexity for problems such as NK-Landscapes and MAXSAT problems. Representations such as real valued encodings, permutations, Gray codes and binary encodings will be discussed. An easy to understand explanation of No Free Lunch theories and their implications for both search and representation will be presented, along with example applications related to the Traveling Salesman Problem, Scheduling, Machine Learning and Neurocontrol. Written tutorials for genetic algorithms and for combining GAs with neural networks are found at: http://www.cs.colostate.edu/~whitley under Publications.
Due to the expansion of the Internet, a change has occured in our life and habits. We can expect that some software agents would work on our behalf, representing our interests and defending our privacy. A principled approach to the achievement of this dream is proposed by the Distributed Constraint Reasoning community which offers a general framework and powerful competitive techniques to approach these important applications. Distributed Constraint Satisfaction aims to offer equal opportunities to participants in cooperative or semi-cooperative distributed resource allocation problems. This tutorial will provide a unified view on Distributed Constraint Reasoning, introducing distributed constraint reasoning systems as semi-cooperative multi-agent systems and concentrating on the communication and organization requirements of such systems. The general ideas behind the known distributed constraint reasoning systems are presented within this multi-agent framework. For each approach, the requirements, limitations, advantages and disadvantages will be discussed. Additional information is available at http://www.cs.fit.edu/~msilaghi/IJCAI03-DCR-TUTORIAL/. Prerequisite knowledge: The tutorial is suitable for a general AI audience, both academic and industrial. Knowledge of some basic search algorithm schemes would be helpful, but it is not essential.
Ants are fascinating social insects. They are only capable of short-range interactions, yet communities of ants are able to solve complex problems efficiently and reliably. Ants have therefore become a source of algorithmic ideas for distributed systems where a robot (or a computer) is the "individual" and a swarm of robots (or the network) plays the role of the "colony". This half-day tutorial gives an overview of the state of the art in ant robotics, an area of artificial intelligence that uses ants as inspiration. Ant robots are simple and cheap robots with limited sensing and computational capabilities. This makes it feasible to deploy teams of ant robots and take advantage of the resulting fault tolerance and parallelism. Ant robots cannot use conventional planning methods due to their limited sensing and computational capabilities. Rather, their behavior is driven by local interactions. For example, ant robots can use trails to follow other ant robots or cover terrain robustly, similar to ants that lay and follow pheromone trails. Ant robotics is a rapidly growing area in both artificial intelligence and robotics. In the past couple of years, researchers have developed ant robot hardware and software and demonstrated, both in simulation and on physical robots, that single ant robots or teams of ant robots solve robot-navigation tasks robustly. Researchers have also developed a theoretical foundation for ant robots, based on ideas from real-time heuristic search, stochastic analysis, and graph theory. This half-day tutorial on the current state of the art in ant robotics is given by experts who will give an overview of this exciting area without assuming any prior knowledge on the topic. It will cover all important aspects of ant robotics, from theoretical foundations to videos of implemented systems. To this end, it will bring together the various research directions for the first time, including theoretical foundations, ant robot hardware, and ant robot software. Its primary objective is to give non-specialists a comprehensive overview of the state of the art of the field, for example, to allow researchers and students to do research in the area and to allow practitioners to evaluate the current state of the art in ant robotics. Consequently, it is of interest to anyone who is interested in multi-agent systems, distributed problem solving, search, mobile robotics, and artificial intelligence in general. For additional information, see http://www.cc.gatech.edu/fac/Sven.Koenig/ijcai03-tutorial.html
Intelligent access and integration of information becomes more and more important with the Internet growing every day. In this tutorial we will discuss the relation between existing research in the area of intelligent information integration and new requirements and technologies that arise from the area of Semantic Web research. We would like to emphasize the importance of information integration on the World Wide Web in the context of providing intelligent access to heterogeneous and distributed information sources and intelligent services. Formal ontologies have been identified to be useful for this process because they provide means to describe the semantics of information explicitly. This is a prerequisite to use logical reasoning. We will start with a motivation why we should use ontologies and will discuss existing solutions to the problem of information integration. We compare these solutions and identify common features of architectures and technologies. Furthermore, we show how these common features relate to Semantic Web architectures and technologies, revealing similarities and differences. Finally, we discuss prospects and challenges for Semantic Web research. We assume that attendees have basic knowledge in the area of data and information modelling. Knowledge about Web-based information systems would be an advantage.
Monday, August 11
The last three years have witnessed a leap of improvement in market clearing algorithms both for traditional market designs and entirely new market designs enabled by advanced clearing technology. This tutorial covers the computational implications of different market designs and presents algorithms for clearing markets optimally and approximately. Auctions, reverse auctions, and exchanges (many-to-many auctions) are covered. Both theoretical and experimental results are presented. Multi-item and multi-unit markets will be a key focus. Computational implications of different classes of side constraints will be presented. Bid types covered include price-quantity bids, different shapes of supply/demand curves, and combinatorial bids. A new method for selective preference elicitation for combinatorial markets is presented.
The last decade has witnessed an increasing interest in Propositional Satisfiability (SAT), with a boost in the performances of SAT solvers. Unfortunately, simple propositional logic is often not expressive enough to solve complex real-world problems. More recently, SAT procedures have been successfully used also as basic inference engines of decision procedures for much more expressive problems, like reasoning in modal and description logics, resource planning, temporal reasoning, formal verification of timed systems, formal verification of circuits at an abstract level. In this tutorial we focus on the latter aspect, and we show how SAT solvers can be correctly and efficiently extended to work with more expressive domains by integrating them with domain-specific procedures. The tutorial is directed to a rather general AI audience, in particular to people interested in various domains of Automated Reasoning and Knowledge Representation, like SAT, decision procedures, reasoning in modal and description logics, planning, temporal reasoning, and also to those people interested in applications of automated reasoning techniques to formal verification. The tutorial assumes only a basic knowledge of logic and AI topics. A background on SAT is of help, but not strictly necessary.
Web services have been gathering much attention lately. Everyone agrees about their fundamental importance to information technology architectures and applications. The main advantage of Web services arises when we can compose them to create new services. Unfortunately, much of the attention on Web services has been focused on the lower-level, infrastructural matters, often down to encoding syntaxes and unnecessarily narrow means of invoking services. This tutorial will present the necessary concepts, architectures, theories, techniques, and infrastructure to use and compose Web services. It will include an overview of the state of the art in selected application areas. This tutorial gives the essential background for anyone planning to learn about and contribute to the principles and applications of service composition. It will guide practitioners by highlighting best practices in service composition and introduce students and advanced developers to the key trade-offs as well as the limitations of current approaches. Some of the key techniques for service composition (e.g., dealing with their discovery and engagement) were developed in the areas of databases, distributed computing, artificial intelligence, and multiagent systems. These are generally established bodies of work that can be readily adapted for service composition. Some additional techniques, although inspired by these areas, must be developed from scratch. This is because for Web services, we must address the essential openness and scale of Web applications that previous work did not need to address. Both classes of key techniques should be incorporated into our best practices for service design and composition. In many cases, they can be applied on top of the existing approaches. Prerequisites: Some experience with Web programming; basic concepts of artificial intelligence.
Teamwork is a fundamental area of multiagents research, with a large number of applications, such as synthetic agent teams in virtual environments for training, software assistant teams to support human organizations, robot-agent-person teams for disaster rescue, etc. This tutorial will survey the state of the art of both the theory and practice of multiagent and agent-human teamwork. We will discuss two key aspects of teamwork theory. The first aspect, based on belief-desire-intention models, will cover the joint intentions theory, SharedPlans theory and others. The second, founded on a decision-theoretic perspective, will cover decentralized partially observable markov decision process (POMDP) models and their applications in analysis of multiagent systems. Half of the tutorial will be devoted to practical systems constructed by exploiting teamwork theory as the basis. Indeed, one key lesson learned in practical systems is that in complex, dynamic environments, creating fixed and domain-specific coordination plans is highly problematic: these plans are not reusable across domains and their lack of flexibility can lead to severe failures. Instead, a new approach based on developing general teamwork models, i.e., domain-independent, reusable team coordination algorithms, appears to provide more promise. We will discuss research on general team coordination algorithms and cover their applications. The last part of the tutorial will cover agent-human teamwork, and key issues in such teamwork, in particular, mixed-initiative and adjustable autonomy.
A central problem in artificial intelligence is how to develop computational models that allow decision-support systems or autonomous agents to react to a situation after performing the right amount of deliberation. Frequently, the complexity of problem solving makes it beneficial to use approximate solutions rather than try to compute the optimal answer. This issue arises in a wide range of application domains including medical trauma management, Bayesian inference, sequence alignment, graphics rendering, web page prefetching, autonomous space exploration, real-time avionics, and robot navigation. This tutorial explores the theory and practice of building intelligent systems that reason explicitly about employing limited computational resources to generate timely solutions to difficult combinatorial optimization, planning and scheduling problems. Solution techniques go beyond simple greedy or reactive algorithms to achieve high-quality solutions while meeting both hard and soft real-time deadlines. We will explore over fifteen years of progress in this area, covering historical perspectives, state of-the-art solution techniques, and current and future challenges. Topics include: Computational tradeoffs in inference, planning, and search; representation and measurement of computational tradeoffs; dependency of performance on problem instances; anytime algorithms and flexible computation; strategies for allocating resources among reasoning subproblems; myopic and non-myopic control; partitioning resources between meta-level and object-level reasoning; applications of resource-bounded systems; and current research challenges. See http://anytime.cs.umass.edu/ijcai-03-tutorial.html Participants should be familiar with introductory artificial intelligence, algorithm design and analysis, and introductory probability and statistics.
*Cancelled
Constraint programming is a technology for declarative description and solving of hard combinatorial problems. The tutorial gives a broad and deep survey of major constraint satisfaction algorithms. First, the notion of a constraint is explained and some examples of practical applications of constraint technology are given. Then we survey the basic search algorithms for solving constraints; both local search and depth-first search methods are presented. The algorithms are explained in an incremental nature showing how the more advanced algorithms are built up on improvements of the simpler algorithms. In the next part we concentrate on the core of constraint satisfaction technology consistency techniques. We explain the main consistency levels like arc and path consistency and we present several algorithms to achieve them. We also describe how the consistency techniques reduce the search space in the depth-first search. The tutorial is concluded with examples of modeling problems using constraints. The tutorial is targeted to a broad AI community, in particular to everyone who is not familiar with the details of constraint satisfaction technology. It introduces novices as well as expert non-specialists to one of the major topics of AI. No prior knowledge of constraint satisfaction is required.
The computational and robotic modeling of language evolution is emerging as a new subfield in AI, and is generating great interest from the many other disciplines interested in this question. The objective is to come up with precise operational models how communities of agents equipped with a cognitive apparatus, a sensori-motor system, and a body, can arrive at shared communication systems that have similar characteristics as human languages. This enormous challenge requires the integration of work in vision and robotics, computational linguistics, and machine learning, but pushes each of these disciplines in new directions. The tutorial reviews work in this area, focusing on all aspects of language: the origins of sound systems, the origins of lexicons, the origins of grammar, and the co-evolution of language and (grounded) meaning. It presents in detail a key experiment for each topic, and surveys the many remaining open problems.
Space and time are ubiquitous parameters of our knowledge about the world. Qualitative spatial and temporal reasoning methods have evolved in order to reason about space and time when precise quantitative information is either superfluous or unavailable. The potential applications of the field include natural language understanding, planning, GIS, robotics, and human-machine communication. This tutorial will guide practitioners by describing the main methods and results in the field, including: basic formalisms for various models of time (including non-linear ones) and space; tractability results in qualitative spatial and temporal calculi; fuzzy extensions of the calculi and applications; spatio-temporal reasoning. The tutorial is suitable for all researchers interested in an overview of the current state of the art in the domain. It assumes only a basic knowledge of AI and Knowledge Representation techniques. The logical notions will be introduced when required.
The most valuable asset of a company is knowledge. The ability to capture, cumulate and re-use knowledge and experience in an effective and efficient manner, gives companies major competitive advantages. Case-Based Reasoning (CBR) allows developing computer systems that store corporate experience in a case-base and enable users to access, re-use and extend this knowledge in a natural and straightforward manner. A CBR system solves new problems by adapting and re-using solutions to previous, similar problems, issues of and solutions for real world knowledge management. It will provide a technical introduction to industrial knowledge management using CBR and illustrate the introduced concepts and issues with examples from deployed industrial applications. Criteria for successful deployment and long-term maintenance and utilization of knowledge management systems will be pointed out and directions for future research will be highlighted. The examples given throughout the tutorial will provide guidelines for the specification, design, implementation, and deployment, as well as the continuous usage of a CBR system. Prerequisite knowledge: The tutorial is suitable for participants with some basic AI knowledge, coming either from an academic or industrial background.
|