Steve Sutphen

Checkers Is Solved

The game of checkers has roughly 500 billion billion possible positions (5 × 1020). The task of solving the game, determining the final result in a game with no mistakes made by either player, is daunting. Since 1989, almost continuously, dozens of computers have been working on solving checkers, applying state-of-the-art artificial intelligence techniques to the proving process. This paper announces that checkers is now solved: Perfect play by both sides leads to a draw. This is the most challenging popular game to be solved to date, roughly one million times as complex as Connect Four. Artificial intelligence technology has been used to generate strong heuristic-based game-playing programs, such as Deep Blue for chess. Solving a game takes this to the next level by replacing the heuristics with perfection.

Cognitive cubes: a tangible user interface for cognitive assessment

Assessments of spatial, constructional ability are used widely in cognitive research and in clinical diagnosis of disease or injury. Some believe that three-dimensional (3D) forms of these assessments would be particularly sensitive, but difficulties with consistency in administration and scoring have limited their use. We describe Cognitive Cubes, a novel computerized tool for 3D constructional assessment that increases consistency and promises improvements in flexibility, reliability, sensitivity and control. Cognitive Cubes makes use of ActiveCube, a novel tangible user interface for describing 3D shape. In testing, Cognitive Cubes was sensitive to differences in cognitive ability and task, and correlated well to a standard paper-and-pencil 3D spatial assessment

Building the Checkers 10-Piece Endgame Databases

In 1993, the Chinook team completed the computation of the 2 through 8-piece checkers endgame databases, consisting of roughly 444 billion positions. Until recently, nobody had attempted to extend this work. In November 2001, we began an effort to compute the 9- and 10-piece databases. By June 2003, the entire 9-piece database and the 5-piece versus 5-piece portion of the 10-piece database were completed. The result is a 13 trillion position database, compressed into 148 GB of data organized for real-time decompression. This represents the largest endgame database initiative yet attempted. The results obtained from these computations are being used to aid an attempt to weakly solve the game. This paper describes our experiences working on building large endgame databases.

A tangible user interface for assessing cognitive mapping ability

Wayfinding, the ability to recall the environment and navigate through it, is an essential cognitive skill relied upon almost every day in a persons life. A crucial component of wayfinding is the construction of cognitive maps, mental representations of the environments through which a person travels. Age, disease or injury can severely affect cognitive mapping, making assessment of this basic survival skill particularly important to clinicians and therapists. Cognitive mapping has also been the focus of decades of basic research by cognitive psychologists. Both communities have evolved a number of techniques for assessing cognitive mapping ability. We present the Cognitive Map Probe (CMP), a new computerized tool for assessment of cognitive mapping ability that increases consistency and promises improvements in flexibility, accessibility, sensitivity and control. The CMP uses a tangible user interface that affords spatial manipulation. We describe the design of the CMP, and find that it is sensitive to factors known to affect cognitive mapping performance in extensive experimental testing.

Spatial Tangible User Interfaces for Cognitive Assessment and Training

This paper discusses Tangible User Interfaces (TUIs) and their potential impact on cognitive assessment and cognitive training. We believe that TUIs, and particularly a subset that we dub spatial TUIs, can extend human computer interaction beyond some of its current limitations. Spatial TUIs exploit human innate spatial and tactile ability in an intuitive and direct manner, affording interaction paradigms that are practically impossible using current interface technology. As proof-of-concept we examine implementations in the field of cognitive assessment and training. In this paper we use Cognitive Cubes, a novel TUI we developed, as an applied test bed for our beliefs, presenting promising experimental results for cognitive assessment of spatial ability, and possibly for training purposes.

Tactile Servo: Control of Touch-Driven Robot Motion

In this paper, a new approach to tactile sensor-based object manipulation is proposed. The approach makes use of the simple observation that the progress of a manipulation task can be characterized by the tactile images produced by tactile sensors mounted on the fingertips of a robot hand. In analogy to image-based visual servo, a control scheme based upon features derived from tactile images is used to control the movement of a robot arm. The approach is applied to derive a control scheme for the task of rolling a cylindrical pin on a planar surface using a planar robot finger equipped with a tactile array sensor. The tactile features used in the control scheme are derived from a theoretical and experimental study of the variation of the normal stress distribution as a result of applied force. The experiment demonstrates that information from array tactile sensors can be used in a simple, direct and effective manner to control manipulation tasks. This approach is currently being extended to other tasks involving a dextrous multi-fingered robot hand.