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Report on the Fourth International Joint Conference on Autonomous Agents and Multiagent Systems (AAMAS 2005)

AI Magazine

Utrecht is more than 1,300 years old and located in the center of the Netherlands, about 40 minutes by train from Amsterdam. School (EASSS 2005) for about 120 students, which was organized by Europe's coordination network for agent systems (AgentLink) and was as successful as previous summer schools in Utrecht, Saarbruecken, Prague, Barcelona, Bologna, and Liverpool. Overall, in the theory and practice of AAMAS 2005 had 778 academic and autonomous agents and multiagent industrial participants from 44 countries systems. AAMAS 2005 is the fourth on six continents. The main room of this can with some justification AAMAS 2005 was held on July building, in which the Treaty of claim to be one of the most active.


Using Educational Robotics to Motivate Complete AI Solutions

AI Magazine

Robotics is a remarkable domain that may be successfully employed in the classroom both to motivate students to tackle hard AI topics and to provide students experience applying AI representations and algorithms to real-world problems. This article uses two example robotics problems to illustrate these themes. We show how the robot obstacle-detection problem can motivate learning neural networks and Bayesian networks. We also show how the robot-localization problem can motivate learning how to build complete solutions based on particle filtering. Since these lessons can be replicated on many low-cost robot platforms they are accessible to a broad population of AI students. We hope that by outlining our educational exercises and providing pointers to additional resources we can help reduce the effort expended by other educators. We believe that expanding handson active learning to additional AI classrooms provides value both to the students and to the future of the field itself.


CMRoboBits: Creating an Intelligent AIBO Robot

AI Magazine

This homework introduces students the material in the course. For the written component to the concept of human/robot interaction of this homework, students have to and learning on a real robot. The students manually calculate a posterior probability of program their AIBOs to play a guessing game the robot's position given a uniform prior distribution by which one player (either the human or the of robot poses in a grid world. AIBO) guesses a sequence of colored markers Mounting a Charging Station. Students use the that the other player (AIBO or human, respectively) object-detection code written in previous makes up ahead of time. The AIBO communicates homework assignments to find a colored bull'seye to the human by a predefined set of and tower beacon. These two landmarks allow the robot to compute the distance and orientation motions. When guessing the colored sequence, of a charging station. The robot needs the AIBO has to reason about the patterns of to search for and then climb onto the charging the colors as well as about the clues given to it station.


Launching into AI's "October Sky with Robotics and Lisp

AI Magazine

Robotics projects coupled with agent-oriented trends in artificial intelligence education have the potential to make introductory AI courses at liberal arts schools the gateway for a large new generation of AI practitioners. However, this vision's achievement requires programming libraries and low-cost platforms that are readily accessible to undergraduates and easily maintainable by instructors at sites with few dedicated resources. This article presents and evaluates one contribution toward implementing this vision: the RCXLisp library. The library was designed to support programming of the Lego Mindstorms platform in AI courses with the goal of using introductory robotics to motivate undergraduates' understanding of AI concepts within the agent-design paradigm. The library's evaluation reflects four years of student feedback on its use in a liberal-arts AI course whose audience covers a wide variety of majors. To help establish a context for judging RCXLisp's effectiveness this article also provides a sketch of the Mindstormsbased laboratory in which the library is used.


Components, Curriculum, and Community: Robots and Robotics in Undergraduate AI Education

AI Magazine

Although the Lego RCX's has helped guide Sony's own choice of Hitachi H8 microcontroller lists at 16 megahertz next-generation AIBO features and software and 32 kilobytes of memory, the overhead support. As for two-legged platforms, the University of the firmware and interpreter yield of Freiburg has already prototyped a about 10 kilobytes and 500 hertz throughput soccer team of Robosapiens running from for a typical user--slightly better with alternative handheld computers.


Unifying Undergraduate Artificial Intelligence Robotics: Layers of Abstraction over Two Channels

AI Magazine

From a computer science and artificial intelligence perspective, robotics often appears as a collection of disjoint, sometimes antagonistic subfields. The lack of a coherent and unified presentation of the field negatively affects teaching, especially to undergraduates. This article presents an alternative synthesis of the various subfields of AI robotics and shows how these traditional subfields fit into the whole. Finally, it presents a curriculum based on these ideas.


Complexity Results and Approximation Strategies for MAP Explanations

Journal of Artificial Intelligence Research

MAP is the problem of finding a most probable instantiation of a set of variables given evidence. MAP has always been perceived to be significantly harder than the related problems of computing the probability of a variable instantiation Pr, or the problem of computing the most probable explanation (MPE). This paper investigates the complexity of MAP in Bayesian networks. Specifically, we show that MAP is complete for NP^PP and provide further negative complexity results for algorithms based on variable elimination. We also show that MAP remains hard even when MPE and Pr become easy. For example, we show that MAP is NP-complete when the networks are restricted to polytrees, and even then can not be effectively approximated. Given the difficulty of computing MAP exactly, and the difficulty of approximating MAP while providing useful guarantees on the resulting approximation, we investigate best effort approximations. We introduce a generic MAP approximation framework. We provide two instantiations of the framework; one for networks which are amenable to exact inference Pr, and one for networks for which even exact inference is too hard. This allows MAP approximation on networks that are too complex to even exactly solve the easier problems, Pr and MPE. Experimental results indicate that using these approximation algorithms provides much better solutions than standard techniques, and provide accurate MAP estimates in many cases.


Distributed Reasoning in a Peer-to-Peer Setting: Application to the Semantic Web

Journal of Artificial Intelligence Research

In a peer-to-peer inference system, each peer can reason locally but can also solicit some of its acquaintances, which are peers sharing part of its vocabulary. In this paper, we consider peer-to-peer inference systems in which the local theory of each peer is a set of propositional clauses defined upon a local vocabulary. An important characteristic of peer-to-peer inference systems is that the global theory (the union of all peer theories) is not known (as opposed to partition-based reasoning systems). The main contribution of this paper is to provide the first consequence finding algorithm in a peer-to-peer setting: DeCA. It is anytime and computes consequences gradually from the solicited peer to peers that are more and more distant. We exhibit a sufficient condition on the acquaintance graph of the peer-to-peer inference system for guaranteeing the completeness of this algorithm. Another important contribution is to apply this general distributed reasoning setting to the setting of the Semantic Web through the Somewhere semantic peer-to-peer data management system. The last contribution of this paper is to provide an experimental analysis of the scalability of the peer-to-peer infrastructure that we propose, on large networks of 1000 peers.


An Approach to Temporal Planning and Scheduling in Domains with Predictable Exogenous Events

Journal of Artificial Intelligence Research

The treatment of exogenous events in planning is practically important in many real-world domains where the preconditions of certain plan actions are affected by such events. In this paper we focus on planning in temporal domains with exogenous events that happen at known times, imposing the constraint that certain actions in the plan must be executed during some predefined time windows. When actions have durations, handling such temporal constraints adds an extra difficulty to planning. We propose an approach to planning in these domains which integrates constraint-based temporal reasoning into a graph-based planning framework using local search. Our techniques are implemented in a planner that took part in the 4th International Planning Competition (IPC-4). A statistical analysis of the results of IPC-4 demonstrates the effectiveness of our approach in terms of both CPU-time and plan quality. Additional experiments show the good performance of the temporal reasoning techniques integrated into our planner.