2635609
Recent progress in local and global traversability for planetary rovers
Autonomous planetary rovers operating in vast unknown environments must operate efficiently because of size, power and computing limitations. Recently, we have developed a rover capable of efficient obstacle avoidance and path planning. The rover uses binocular stereo vision to sense potentially cluttered outdoor environments. Navigation is performed by a combination of several modules that each "vote" for the next best action for the robot to execute. The key distinction of our system is that it produces globally intelligent behavior with a small computational resource - all processing and decision making are done on a single processor. These algorithms have been tested on our outdoor prototype rover, Bullwinkle, and have recently driven the rover 100 m at a speed of 15 cm/sec. In this paper we report on the extension on the systems that we have previously developed that were necessary to achieve autonomous navigation in this domain.
668272
First Results in the Coordination of Heterogeneous Robots for Large-Scale Assembly
While many multi-robot systems rely on fortuitous cooperation between agents, some tasks, such as the assembly of large structures, require tighter coordination. We present a general software architecture for coordinating heterogeneous robots that allows for both autonomy of the individual agents as well as explicit coordination. This paper presents recent results with three robots with very different configurations. Working as a team, these robots are able to perform a high-precision docking task that none could achieve individually.
1211760
Heuristic Search Value Iteration for POMDPs
We present a novel POMDP planning algorithm called heuristic search value iteration (HSVI). HSVI is an anytime algorithm that returns a policy and a provable bound on its regret with respect to the optimal policy. HSVI gets its power by combining two well-known techniques: attention-focusing search heuristics and piecewise linear convex representations of the value function. HSVI's soundness and convergence have been proven. On some bench-mark problems from the literature, HSVI displays speedups of greater than 100 with respect to other state-of-the-art POMDP value iteration algorithms. We also apply HSVI to a new rover exploration problem 10 times larger than most POMDP problems in the literature.
3284353
Point-Based POMDP Algorithms: Improved Analysis and Implementation
Existing complexity bounds for point-based POMDP value iteration algorithms focus either on the curse of dimensionality or the curse of history. We derive a new bound that relies on both and uses the concept of discounted reachability; our conclusions may help guide future algorithm design. We also discuss recent improvements to our (point-based) heuristic search value iteration algorithm. Our new implementation calculates tighter initial bounds, avoids solving linear programs, and makes more effective use of sparsity.
17905377
FLANNEL: adding computation to electronic mail during transmission
In this paper, we describe FLANNEL, an architecture for adding computational capabilities to email. FLANNEL allows email to be modified by an application while in transit between sender and receiver. This modification is done without modification to the endpoints---mail clients---at either end. This paper also describes interaction techniques that we have developed to allow senders of email to quickly and easily select computations to be performed by FLANNEL. Through, our experience, we explain the properties that applications must have in order to be successful in the context of FLANNEL.
10411630
The ADEPT Concept-Based Digital Learning Environment
We describe the design and application of a Digital Learning Environment (DLE) that is integrated with the collections and services of the Alexandria Digital Library (ADL). This DLE is in operational use in undergraduate teaching environments. Its design and development incorporate the assumption that deep understanding of both scientific phenomena and scientific methods is facilitated when learning materials are explicitly organized, accessed and presented at the level of granularity of appropriate sets of scientific concepts and their interrelationships. The DLE supports services for the creating, searching, and displaying: (1) knowledge bases (KBs) of strongly structured models of scientific concepts; (2) DL collections of information objects organized and accessible by the concepts of the KBs; and (3) collections of presentation materials, such as lectures and laboratory materials, that are organized as trajectories through the KB of concepts.
10464813
Building Semantic Tools for Concept-based Learning Spaces: Knowledge Bases of Strongly-Structured Models for Scientific Concepts in Advanced Digital Libraries
Applying conventional principles of knowledge organization, representation, and other semantic tools, we have constructed a model for scientific concepts and employed knowledge bases and visualization tools to represent knowledge concerning scientific concepts. Strongly-structured models, such as the integration of a taxonomy (or thesaurus) with metadata (or attribute-value pairs) and domain-specific markup languages, as well as specialized models for learning scientific concepts, focus on such attributes as objective representations, operational semantics, use, and interrelationships of concepts. All of these play important roles in constructing representations of knowledge in most domains of science. Instructional activities for undergraduate teaching and learning are greatly facilitated with the use of such integrated semantic tools.
7260476
Visual Explorations for the Alexandria Digital Earth Prototype
The Alexandria Digital Earth Prototype project addresses issues of access, browsing, delivery and understanding of georeferenced library items. Two visualization approaches that address these issues in different ways are under development: interfaces between some existing digital earth systems and the digital library, and spatial but nongeoreferenced information spaces. Both the abstract spatial and georeferenced projects are being evaluated for their educational potential in classroom and lectures, in labs and as tools for students to use on their own.
12515579
Supporting serendipitous integration in mobile computing environments
Abstract In the richly networked world of the near future, mobile computing users will be confronted with an ever-expanding array of devices and services accessible in their environments. In such a world, we cannot expect to have available to us specific applications that allow us to accomplish every conceivable combination of devices that we may wish. Instead, we believe that many of our interactions with the network will be characterized by the use of “general purpose” tools that allow us to discover, use, and integrate multiple devices around us. This paper lays out the case for why we believe that so-called “serendipitous integration” is a necessary fact that we will face in mobile computing, and explores a number of design experiments into supporting end user configuration and control of networked environments through general purpose tools. We present an iterative design approach to creating such tools and their user interfaces, discuss our observations about the challenges of designing for such a world, and then explore a number of tools that take differing design approaches to overcoming these challenges. We conclude with a set of reflections on the user experience issues that we believe are inherent in dealing with ad hoc mobile computing in richly networked environments.