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Department of Electrical Engineering and
Computer Science
University of Wisconsin Milwaukee.
- BNG -
Bayesian Network Generator
BNG is a tools for constructing structurally minimal Bayesian
Networks from universally quantified probability logic statements
with optional context contrainsts.
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Investigators
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Current Status
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BNG is a system for knowledge-based construction of Bayesian
networks. A class of Bayesian networks is specified with a
knowledge base of rules. Rules may contain universally
quantified temporal and non-temporal variables, as well as
context constraints. Context constraints are deterministic
information used to index probabilistic relations. Given a
knowledge base, a set of context information, some evidence,
and a query, BNG constructs the structurally minimal Bayesian
network to compute the posterior probability of the query given
the evidence within the given context. This is done by first
constructing the network, as indexed by the context and then
performing fast d-separation based pruning. The pruning is made
efficient by incorporating it in the network construction
process.
BNG provides both representational and computational advantages
over the use of traditional Bayesian networks. The
incorporation of quantified variables in the knowledge base
allows the representation of information not expressible in
traditional Bayesian networks. Because only a small portion
of a large probabilistic model may be relevant to the
computation of a particular posterior probability, use of BNG
can result in significant computational savings. These savings
can be particularly large with temporal Bayesian networks.
The knowledge base representation language has a declarative
semantics and the network construction algorithm has been
proven sound and complete.
BNG is written in CommonLisp and interfaces to IDEAL.
A user manual and example files are provided.
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Software
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Publications
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- Ngo L, Haddawy P. Answering queries from context-sensitive
probabilistic knowledge bases. Submitted to Theoretical
Computer Science special issue on Uncertainty in Databases
and Deductive Systems, March, 1995.
[
Compressed PostScript]
- Ngo L, Haddawy P, Helwig J. A theoretical framework for
context-sensitive temporal probability model construction
with application to plan projection. In: Proceedings
UAI-95, pp. 419-426, August 1995.
[
Compressed PostScript]
- Haddawy P, Helwig J, Ngo L, Krieger R. Clinical simulation
using context-sensitive temporal probability models.
Proceedings of the 19th Annual Symposium on Computer
Applications in Medical Care 1995:203-207.
[
Compressed PostScript]
- Haddawy P, Generating Bayesian networks from probability
logic knowledge bases. In: Proceedings UAI-94, pp.
262-269, July 1994.
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Compressed PostScript]
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