About Me


I am currently a PhD student in Prof. Rina Dechter’s Automated Reasoning group.

Graphical models are a widely used framework for reasoning tasks. I am particularly interested in search-based approaches to inference augmented with standard variable elimination techniques.

I have worked on exploring the AND/OR Decision Diagram framework for performing inference and evaluating its quality on solving high-treewidth problems with problem specific structures such as determinism and context-specific independence.

I am currently working on dynamic heuristics for AND/OR Branch and Bound. This work aims to find a good tradeoff between heuristic computation and node expansion in AOBB.


As of December 2012, I earned my MS in Computer Science from UC Irvine.

Before UC Irvine, I earned my BS in Computer Science from UC Riverside in 2010. There, I worked as an undergraduate research assistant in R-LAIR (Riverside Lab for Artificial Intelligence Research) with Prof. Christian Shelton.

I worked on the CTBN-RLE code base. Specifically, I implemented the structure learning component, which learns a Bayesian network and continuous time Bayesian network structure from trajectory data. It seamlessly incorporates any of the inference methods available in CTBN-RLE to handle the case of partially observed trajectories. I also implemented mean field variational approximate inference for CTBNs, the algorithm described in Cohn et al. 2009.

Publications
William Lam and Rina Dechter.
Empirical Evaluation of AND/OR Multivalued Decision Diagrams for Inference.
In Doctoral Programme of CP 2012, Québec City, QC, Canada, October 2012.
[pdf | extended version]
E. Busra Celikkaya, Christian R. Shelton, and William Lam.
Factored Filtering of Continuous-Time Systems.
In Proceedings of UAI 2011, Barcelona, Spain, July 2011.
[pdf]
Christian R. Shelton, Yu Fan, William Lam, Joon Lee, and Jing Xu.
Continuous Time Bayesian Network Reasoning and Learning Engine.
In Journal of Machine Learning Research, 11, 1137-1140.
[link]