By Topic

Ancestor controlled submodule inclusion in design databases

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Yu, L. ; Dept. of Comput. Sci., State Univ. of New York, Albany, NY, USA ; Rosenkrantz, D.J.

A paradigm is proposed for representing hierarchically specified design data in CAD database systems in which there are alternate expansions of hierarchically specified modules. The paradigm uses an ancestor-based scheme to control which instances of submodules are to be placed in the expansion of each instance of a given module and is formalized using a versioned directed acyclic multigraph (VDAG). The approach is aimed at reducing storage space in engineering design database systems and at providing a means for designers to specify alternate expansions of a module. The VDAG model is defined, and a mechanism by which a VDAG generates an exploded forest of design trees is described. Algorithms are provided to generate a design forest from a given VDAG, determine whether one module is contained by a larger module, extract a version from a VDAG, test whether two VDAGs are equivalent, and try to reduce the size of a VDAG. The problems of module containment and VDAG inequivalence are shown to be NP-complete, and the problem of finding a minimum sized VDAG equivalent to a given VDAG is shown to be NP-hard

Published in:

Knowledge and Data Engineering, IEEE Transactions on  (Volume:5 ,  Issue: 2 )