Goto

Collaborating Authors

 Overview


Bridging Common Sense Knowledge Bases with Analogy by Graph Similarity

AAAI Conferences

Present-day programs are brittle as computers are notoriously lacking in common sense. While significant progress has been made in building large common sense knowledge bases, they are intrinsically incomplete and inconsistent. This paper presents a novel approach to bridging the gaps between multiple knowledge bases, making it possible to answer queries based on knowledge collected from multiple sources without a common ontology. New assertions are found by computing graph similarity with principle component analysis to draw analogies across multiple knowledge bases. Experiments are designed to find new assertions for a Chinese commonsense knowledge base using the OMCS ConceptNet and similarly for WordNet. The assertions are voted by online users to verify that 75.77% / 77.59% for Chinese ConceptNet / WordNet respectively are good, despite the low overlap in coverage among the knowledge bases.


A Travel-Time Optimizing Edge Weighting Scheme for Dynamic Re-Planning

AAAI Conferences

The success of autonomous vehicles has made path planning in real, physically grounded environments an increasingly important problem. In environments where speed matters and vehicles must maneuver around obstructions, such as autonomous car navigation in hostile environments, the speed with which real vehicles can traverse a path is often dependent on the sharpness of the corners on the path as well as the length of path edges. We present an algorithm that incorporates the use of the turn angle through path nodes as a limiting factor for vehicle speed. Vehicle speed is then used in a time-weighting calculation for each edge. This allows the path planning algorithm to choose potentially longer paths, with less turns in order to minimize path traversal time. Results simulated in the Breve environment show that travel time can be reduced over the solution obtained using the Anytime D* Algorithm by approximately 10% for a vehicle that is speed limited based on turn rate.


An Analysis of Current Trends in CBR Research Using Multi-View Clustering

AI Magazine

The European Conference on Case-Based Reasoning (CBR) in 2008 marked 15 years of international and European CBR conferences where almost seven hundred research papers were published. In this report we review the research themes covered in these papers and identify the topics that are active at the moment. The main mechanism for this analysis is a clustering of the research papers based on both co-citation links and text similarity. It is interesting to note that the core set of papers has attracted citations from almost three thousand papers outside the conference collection so it is clear that the CBR conferences are a sub-part of a much larger whole. It is remarkable that the research themes revealed by this analysis do not map directly to the sub-topics of CBR that might appear in a textbook. Instead they reflect the applications-oriented focus of CBR research, and cover the promising application areas and research challenges that are faced.


SARA 2009: The Eighth Symposium on Abstraction, Reformulation and Approximation

AI Magazine

The considerable interest in ARA techniques and the great diversity of the researchers involved had led to work on ARA being presented at many different venues. Consequently, there was a need to have a single forum where researchers of different backgrounds and disciplines could discuss their work on ARA. As a result, the Symposium on Abstraction, Reformulation, and Approximation (SARA) was established in 1994 after a series of workshops in 1988, 1990, and 1992. The current SARA, held at Lake Arrowhead, California, USA, on July 7-10, 2009, is the eighth in this series, following symposia in 1994, 1995, 1998, 2000, 2002, 2005, and 2007. Following a SARA tradition, this symposium brought together researchers with different backgrounds and facilitated lively discussions during and after the talks. There were 30 researchers from North and South America, Europe, and Australia. Additionally, SARA attendees were able to mingle and have fruitful discussions with members of the collocated Symposium on Combinatorial Search (SoCS). The collocation of SoCS was particularly useful in that many modern techniques in combinatorial search frequently utilize ARA methods. Finally, in addition to the regular and poster talks, there were three invited talks delivered by Jeff Orkin (Massachusetts Institute of Technology), Michael Genesereth (Stanford University), and Robert Holte (University of Alberta).


Report on the 2008 Reinforcement Learning Competition

AI Magazine

This article reports on the 2008 Reinforcement Learning Competition,  which began in November 2007 and ended with a workshop at the  International Conference on Machine Learning (ICML) in July 2008 in  Helsinki, Finland.  Researchers from around the world developed  reinforcement learning agents to compete in six problems of various  complexity and difficulty.  The competition employed fundamentally  redesigned evaluation frameworks that, unlike those in previous  competitions, aimed to systematically encourage the submission of  robust learning methods. We describe the unique challenges of  empirical evaluation in reinforcement learning and briefly review  the history of the previous competitions and the evaluation  frameworks they employed.  We also describe the novel frameworks  developed for the 2008 competition as well as the software  infrastructure on which they rely.  Furthermore, we describe the six  competition domains and present a summary of selected competition  results.  Finally, we discuss the implications of these results and  outline ideas for the future of the competition.


The Third Competition on Knowledge Engineering for Planning and Scheduling

AI Magazine

We report on the staging of the third competition on knowledge engineering for AI planning and scheduling systems, held during ICAPS-09 at Thessaloniki, Greece in September 2009. We give an overview of how the competition has developed since its first run in 2005, and its relationship with the AI planning field. This run of the competition focused on translators that when input with some formal description in an application-area-specific language, output solver-ready domain models. Despite a fairly narrow focus within knowledge engineering, seven teams took part in what turned out to be a very interesting and successful competition.


Hierarchical Clustering for Finding Symmetries and Other Patterns in Massive, High Dimensional Datasets

arXiv.org Machine Learning

Data analysis and data mining are concerned with unsupervised pattern finding and structure determination in data sets. "Structure" can be understood as symmetry and a range of symmetries are expressed by hierarchy. Such symmetries directly point to invariants, that pinpoint intrinsic properties of the data and of the background empirical domain of interest. We review many aspects of hierarchy here, including ultrametric topology, generalized ultrametric, linkages with lattices and other discrete algebraic structures and with p-adic number representations. By focusing on symmetries in data we have a powerful means of structuring and analyzing massive, high dimensional data stores. We illustrate the powerfulness of hierarchical clustering in case studies in chemistry and finance, and we provide pointers to other published case studies.


Learning Maps of Indoor Environments Based on Human Activity

AAAI Conferences

We present a novel approach to build approximate maps of structured environments utilizing human motion and activity. Our approach uses data recorded with a data suit which is equipped with several IMUs to detect movements of a person and door opening and closing events. In our approach we interpret the movements as motion constraints and door handling events as landmark detections in a graph-based SLAM framework. As we cannot distinguish between individual doors, we employ a multi-hypothesis approach on top of the SLAM system to deal with the high data-association uncertainty. As a result, our approach is able to accurately and robustly recover the trajectory of the person. We additionally take advantage of the fact that people traverse free space and that doors separate rooms to recover the geometric structure of the environment after the graph optimization. We evaluate our approach in several experiments carried out with different users and in environments of different types.


Challenges in Semantics for Computer-Aided Designs

AAAI Conferences

This paper presents a brief summary of a number of different approaches to the semantic representation and automated interpretation of engineering data. In this context, engineering data is represented as Computer-Aided Design (CAD) files, 3D models or assemblies. Representing and reasoning about these objects is a highly interdisciplinary problem, requiring techniques that can handle the complex interactions and data types that occur in the engineering domain. This paper presents several examples, taken from different problem areas that have occupied engineering and computer science researchers over the past 15 years. Many of the issues raised by these problems remain open, and the experience of past efforts can serve to identify fertile opportunities for investigation today.


The Design Compass: A Computer Tool for Scaffolding Students' Metacognition and Discussion about their Engineering Design Process

AAAI Conferences

This paper reports on the Design Compass, a classroom tool for helping students record and reflect on their design process as they work on and complete a design challenge. The Design Compass software provides an interface where students can identify and record the various design steps they used while performing them, and add digital notes and pictures to document their work. In the Design Log view, students can review steps taken, and print the record of work done, which can be shared and discussed with their instructor or classmates. The paper describes the concepts underlying the creation of the Design Compass, its features as a metacognitive tool and how it works, and provides scenarios of its use as a teaching and assessment tool with eighth-grade technology education students, and in teacher professional development workshops.