Principles of Knowledge Representation and Reasoning in the FRAPPE System

The purpose of this paper is to elucidate the following four important architectural principles of knowledge representation and reasoning with the example of an implemented system: limited reasoning, truth maintenance, hybrid architecture, and many sorted logic.MIT Artificial Intelligence Laborator

Interaction with constraints in 3D modeling

Journal ArticleInteractive geometric modeling is an important part of the industrial product design process. This paper describes how constraints can be used to facilitate the interactive definition of geometric objects and assemblies. We have implemented a geometric modeling system that combines the definition of objects by interactive construction operations and specification of geometric constraints. The modeling operations automatically generate constraints to maintain the properties intended by their invocation, and constraints, in turn, determine the degrees of freedom for further interactive mouse-controlled modeling operations. A symbolic geometry constraint solver is employed for solving systems of constraints

Organizing the tasks in complex design projects

"October 1989, revised December 1989."Includes bibliographical references (leaves 16-19).by Steven D. Eppinger and Daniel E. Whitney

An interactive N-Dimensional constraint system

Journal ArticleIn this paper, we present a graph-based approach to geometric constraint solving. Geometric primitives (points, lines, circles, planes, etc.) possess intrinsic degrees of freedom in their embedding space. Constraints reduce the degrees of freedom of a set of objects. A constraint graph is created with objects as the nodes, and the constraints as the arcs. A graph algorithm transforms the undirected constraint graph into a directed acyclic dependency graph which can be directly used to derive a sequence of construction operations as a symbolic solution to the constraint problem. The approach has been generalized to an n-dimensional space, which, among other things, allows for a uniform handling of 2-D and 3-D constraint problems or algebraic constraints between scalar dimension. Solutions of arbitrary dimensions can be interpreted as approaches to over- and under- constrained problems. In this paper, we present the theoretical background of the approach, and report the results of it's application within an interactive modeling system

A model-based method for organizing tasks in product development

"Revised November 1993."Includes bibliographical references (p. 18-20).Funded jointly by the National Science Foundation, General Motors Corporation and MIT Leaders for Manufacturing Program.Steven D. Eppinger ... [et al.]

A Proposal For An Intelligent Debugging Assistant

There are many ways to find bugs in programs. For example, observed input and output values can be compared to predicted values. An execution trace can be examined to locate errors in control flow. The utility of these and other strategies depends on the quality of the specifications available. The Debugging Assistant chooses the most appropriate debugging strategy based on the specification information available and the context of the bug. Particular attention has been given to applying techniques from the domain of hardware troubleshooting to the domain of software debugging. This has revealed two important differences between the two domains: (1) Unlike circuits, programs rarely come with complete specifications of their behavior, and (2) Unlike circuits, the cost of probing inputs and outputs of programs is low.MIT Artificial Intelligence Laborator

What to Read: A Biased Guide to AI Literacy for the Beginner

Acknowledgements. It was Ken Forbus' idea, and he, Howie Shrobe, Dan Weld, and John Batali read various drafts. Dan Huttenlocher and Tom Knight helped with the speech recognition section. The science fiction section was prepared with the aid of my SF/AI editorial board, consisting of Carl Feynman and David Wallace, and of the ArpaNet SF-Lovers community. Even so, all responsibility rests with me.This note tries to provide a quick guide to AI literacy for the beginning AI hacker and for the experienced AI hacker or two whose scholarship isn't what it should be. most will recognize it as the same old list of classic papers, give or take a few that I feel to be under- or over-rated. It is not guaranteed to be thorough or balanced or anything like that.MIT Artificial Intelligence Laborator

Automating Tolerance Synthesis: A Framework and Tools

This paper describes CASCADE-T—a new approach to tolerance synthesis that uses a complete representation of the conditional tolerance relations that exist between features of a part under design. Conditional tolerances are automatically determined from functional requirements and shape information. Tolerance primitives based on the virtual boundary requirements approach to tolerance representation are composed to form more complex tolerance relationships. Artificial intelligence techniques, including a constraint network, frame-based system, and dependency tracking are used to support flexible and detailed computation for tolerance analysis and synthesis