William B. Thompson

IROS Conference 1998 Conference Paper

Smart sensor snow

• Thomas C. Henderson
• Mohamed Dekhil
• Scott Morris 0002
• Yu Chen
• William B. Thompson

We propose to deploy and exploit a large number of inexpensive sensors to obtain information or trigger actions over a wide geographic area. Sensors may be of diverse physical natures: acoustic, IR, seismic, chemical, magnetic, thermal, etc. We describe three major issues: (1) sensor distribution patterns, (2) local sensor frames, and (3) autonomous robot sensor snow exploitation techniques.

ICRA Conference 1994 Conference Paper

Pursuing Projections: Keeping a Robot on Path

• Karen T. Sutherland
• William B. Thompson

For an autonomous robot navigating in an unstructured outdoor environment, staying close to a path is crucial to successfully reaching its goal. Although the degree of accuracy with which it estimates its own location affects its ability to stay on the path, accuracy in estimate of lateral distance from the path is far more important for successful navigation than accuracy in estimate of position along the path. Utilizing methods based only on relative angular measurements between landmarks in the environment, we draw from techniques used in statistical pattern recognition to show how landmarks can be chosen for localization which will not only give good estimate of location in spite of the measurement error, but will also keep the robot on the path. We demonstrate how identical landmark configurations can produce very different results in localizing to a path and show how simple heuristics can be used to choose the best configuration for path localization. >

AIJ Journal 1992 Journal Article

Reconstructive expert system explanation

• Michael R. Wick
• William B. Thompson

Existing explanation facilities are typically far more appropriate for knowledge engineers engaged in system maintenance than for end-users of the system. This is because the explanation is little more than a trace of the detailed problem-solving steps. An alternative approach recognizes that an effective explanation often needs to substantially reorganize the actual line of reasoning and bring to bear additional information to support the result. Explanation itself becomes a complex problem-solving process that depends not only on the actual line of reasoning, but also on additional knowledge of the domain. This paper presents a new computational model of explanation and argues that it results in significant improvements over traditional approaches.

IJCAI Conference 1989 Conference Paper

Reconstructive Explanation: Explanation as Complex Problem Solving

• Michael R. Wick
• William B. Thompson

Existing explanation facilities are typically far more appropriate for knowledge engineers engaged in system maintenance than for endusers of the system. This is because the explanation is little more than a trace of the detailed problem-solving steps. An alternative approach recognizes that an effective explanation often needs to substantially reorganize the line of reasoning and bring to bear additional information to support the result. Explanation itself becomes a complex problem-solving process that depends not only on the line of reasoning, but also on additional knowledge of the domain. We present a new computational model of explanation and argue that it results in significant improvements over traditional approaches.

AAAI Conference 1987 Conference Paper

Shadow Stereo–Locating Object Boundaries Using Shadows

• William B. Thompson

Shadows are a useful source of information about object structure. Shadowscast under oblique lighting often indicate the location of the silhouette of an object. This paper describes a method for reliably detecting shadow edges corresponding to object edges. It is able to distinguish betweendetectededges due to shadows and those due to surface markings. The basis of the technique is to observe the differences in shadowsdue to changesin the direction of illumination. Analysis is further aided by a simple stereotechniquethat doesnot require a solution to the generalcorrespondenceproblem. Both the multi-light source and multi-camera methods can be implementedin an extremely efficient manner.

IJCAI Conference 1983 Conference Paper

Diagnostic Reasoning in Software Fault Localization

• Robert L. Sedlmeyer
• William B. Thompson
• Paul E. Johnson

IJCAI Conference 1983 Conference Paper

Recognition-Based Diagnostic Reasoning

• William B. Thompson
• Paul E. Johnson
• James B. Moen

AAAI Conference 1982 Conference Paper

Edge Detection in Optical Flow Fields

• William B. Thompson

Optical flow is potentially valuable as a source of spatial information. Current techniques provide flow fields which are noisy and sparse, making the recovery of spatial proper ties difficult at best. This paper describes a technique for locating discontinuities in optical flow, which typically correspond to object boundaries. A simple blurring interpolator is used to smooth out noise and produce denser fields. Discontinuities are found by locating the vector field equivalent of zero crossings in the Laplacian of a scalar field. The technique is illustrated by applying it to realistic vector fields which are both noisy and sparse.

IJCAI Conference 1981 Conference Paper

Learning And Abstraction In Simulation

• Strolling Down The Garden Path: Error Prone Tasks in Expert Problem Solving Paul E. Johnson
• William B. Thompson

AAAI Conference 1980 Conference Paper

What Should be Computed In Low Level Vision Systems

• William B. Thompson