SHARON@SU-SCORE.ARPA (07/02/84)
From: Sharon Bergman <SHARON@SU-SCORE.ARPA>
[Forwarded from the Stanford bboard by Laws@SRI-AI.]
KNOWLEDGE-BASED CIRCUIT DESIGN
Christopher Tong
Computer Science Department
Stanford University
Dissertation defense
2:30 p.m., Tuesday, July 17, 1984
Margaret Jacks Hall 146
DESIGN AS DIALECTIC. Design is a dialectic between the designer and what is
possible. As design of an artifact, circuit design involves creating artifact
descriptions that satisfy the requirements imposed by designer, environment,
domain, logic, and limited experience; good design exploits these requirements
of the design problem by converting them into constraints on the design
process. As design of a functionally decomposable artifact, circuit design
entails recursive partitioning of functional requirements in such a way that
the partitioned requirements map onto technologically available structures that
satisfy them. Finally, viewing circuit design as the design of a physical
computational system, we can categorize the required functionality along a
small number of functional dimensions (e.g. control, communication, behavior).
This thesis makes several contributions. It introduces the notion of a
playful design process as an ideal toward which the engineering of design
knowledge should be steered; it describes the extent to which the "playful
design" ideal can be realized by a circuit design process. It extends the
notion of play to playful control of the design process; and finally, it
presents an ontology of dimensions for categorizing and relating design
requirements and approaches.
A PLAYFUL DESIGN PROCESS. Play is doing what one wants to do when wants to do
it. Playful design is possible to the degree that: refinement steps can be
carried out in an order-insensitive manner; and decomposition creates
context-insensitive components. We show that the benefits derived from enabling
such play in the process of design include: enablement of goal-directed
refinement, and an exponential reduction in number of solutions considered over
a more traditional "fixed phases" approach to circuit design. By characterizing
circuit specifications by the ubiquitous functional dimensions of control,
communication, and behavior, we enable a measure of order-insensitive
refinement; these functional dimensions induce a set of evaluation dimensions
for performing goal-directed refinement. Viewing components as processors
facilitates context-insensitive decomposition.
PLAYFUL CONTROL OF THE DESIGN PROCESS. Playful control entails being able to
resolve current design problems by pursuing strategies that are appropriate
given the resource limitations of the designer. Playful control is possible to
the extent that: the problems produced by the design process are
well-categorized; and problem posting and resolution can be separated. Playful
control is knowledge-intensive, drawing on a library of strategies indexed by
problem type and resource allocation.
We describe an interactive computer program called DONTE (Design
ONTology Experiment). DONTE has served to implement, motivate, and help debug
the contributions made by this research.