Planning and Explanations with a Learned Spatial Model

This paper reports on a robot controller that learns and applies a cognitively-based spatial model as it travels in challenging, real-world indoor spaces. The model not only describes indoor space, but also supports robust, model-based planning. Together with the spatial model, the controller\u27s reasoning framework allows it to explain and defend its decisions in accessible natural language. The novel contributions of this paper are an enhanced cognitive spatial model that facilitates successful reasoning and planning, and the ability to explain navigation choices for a complex environment. Empirical evidence is provided by simulation of a commercial robot in a large, complex, realistic world

Learning New Spatially-Oriented Game-Playing Agents through Experience

As they gain expertise in problem solving, people increasingly rely on patterns and spatially-oriented reasoning. This paper describes the integration of an associative visual pattern classifier and the automated acquisition of new, spatially-oriented reasoning agents that simulate such behavior. They are incorporated into a game-learning program whose architecture robustly combines agents with conflicting perspectives. When tested on three games, the visual pattern classifier leams meaningful patterns, and the pattern-based, spatially-oriented agents generalized fi-om these patterns are generally correct. The trustworthiness and relevance of these agents are confirmed with an algorithm that measures the accuracy of the contribution of each agent to the decision-making process. Much of the knowledge encapsulated by the correct new agents was previously inexpressible in the program's representation and in some cases is not readily deducible from the rules

Skilled like a Person: A Comparison of Human and Computer Game Playing

The subject of this paper is the role of transferable commonsense principles in the acquisition of gameplaying expertise. W e argue that individuals skilled in a domain develop expertise because they know and apply these principles, and that most game-playing programs do not play like people. The paper describes Hoyle, a model of an expert game player that relies on the use of commonsense principles, limited memory, and useful knowledge to learn to play two-person, perfect information finite-board games expertly. W e then describe an experiment in which human subjects played three such games against a computer expert. After playing these games, the subjects evaluated Hoyle's game-playing principles in the context of their own behavior Verbal protocols and subjects' evaluations revealed considerable overlap between the principles preferred by our subjects and those preferred by Hoyle. Using learning time as a measure of difficulty, the subjects' performance and Hoyle's performance ordered the three games identically. This experiment also revealed differences in the use of gameplaying principles between skilled and unskilled players: skilled players judged the game-playing principles to be more effective than did unskilled players, skilled players used several different principles while unskilled players relied on one principle, and skilled players anticipated their opponent's moves while unskilled players merely reacted

Foreign Aid Reform: Agency Coordination

This report discusses the many agencies involved with U.S. foreign assistance, the mechanisms currently in place to coordinate foreign aid programs, particularly those related to development assistance, and agency coordination issues that Congress may consider as part of foreign assistance reform

SO_2-rock interaction on Io 2. Interaction with pure SO_2

A Na-S mineral on the surface of Io is required to be the source of the famous atomic cloud. SO_2 is a confirmed atmospheric and surface constituent, and because of the rapid volcanic resurfacing rate, the SO_2 is buried within the crust, where at least occasionally, over many cycles of burial and eruption, it must contact silicate materials at midlevel crustal temperatures. Surface interaction experiments were performed for a wide variety of silicate compositions showing that interaction products of these with SO_2 could be observed at 1123 K on laboratory timescales, even in the absence of external redox agents. Not all experiments produced deposits that could be studied by scanning electron microscopy; some required the greater sensitivity of photoelectron spectroscopy (XPS). Characterization of the alteration products by XPS showed that both oxidized and reduced sulfur species were formed, indicating that a disproportionation mechanism producing a sulfate and a reduced S species although smaller amounts of interaction leading to Na_2SO_3 formation cannot be ruled out. The reduced sulfur species is best explained as elemental S which was independently documented for two compositions. Scanning electron microscopy studies for those compositions where reaction was extensive enough to be observed showed (1) Na_2SO_4 for a soda-lime composition, (2) a mixed Na-Ca-sulfate liquid and CaSO_4 for AbAnDi and a chondrule glass composition, and (3) Fe-sulfate for a natural obsidian. Infrared spectroscopy for the soda-lime glass composition showed peaks best explained by Na_2SO_4. We conclude that SO_2 disproportionation as well as direct formation from SO_3 under oxidizing conditions can produce Na_2SO_4 by interaction of SO_2 with silicates on Io, but Ca and Fe sulfates may form preferentially in more basaltic compositions. As highly oxidizing conditions may be unlikely for Io, the disproportionation mechanism may be more competitive on Io than it is in laboratory experiments. Very low rates of Na_2SO_4 production are required to supply the Io atomic cloud, so the interaction processes can be very inefficient

State, Foreign Operations, and Related Programs: FY2013 Budget and Appropriations

This report analyzes the FY2013 request and congressional action related to FY2013 State-Foreign Operations legislation. The 112th Congress is considering FY2013 international affairs funding within the context of the Budget Control Act that established discretionary spending limits for FY2012-FY2021 and contains automatic budget reductions (sequestration) on discretionary spending to begin on January 2, 2013