About Me
I was a PhD student in Prof. Rina Dechter’s Automated Reasoning group. I am currently a Software Engineer at Google working on Personal Data Infrastructure.
I successfully defended my thesis, titled "Advancing Heuristics for Search over Graphical Models", in March 2017, submitted the final version in May 2017, and officially received my degree in June 2017.
The main contributions of my graduate work included improvements over state-of-the-art heuristics used within the AND/OR search framework to extend the reach of search algorithms for both exact and anytime MPE inference. I also explored the AND/OR Decision Diagram framework, using it to performing exact inference on high treewidth problems with problem specific structures such as determinism and context-specific independence.
Before UC Irvine, I was an undergraduate research assistant in R-LAIR (Riverside Lab for Artificial Intelligence Research) with Prof. Christian Shelton at UC Riverside.
I worked on the CTBN-RLE code base. Specifically, I implemented the structure learning component, which learns Bayesian network and continuous time Bayesian network structures from trajectory data. It seamlessly incorporates any of the inference methods available in CTBN-RLE to handle the case of partially observed trajectories through structural EM. I also implemented the mean field variational inference algorithm inside CTBN-RLE.
| Education |
|---|
| PhD in Computer Science (September 2010 - June 2017) Bren School of Information and Computer Sciences, UC Irvine. |
| MS in Computer Science (September 2010 - December 2012) Bren School of Information and Computer Sciences, UC Irvine. |
| BS in Computer Science (September 2006 - June 2010) Bourns College of Engineering, UC Riverside. |
| Work Experience |
|---|
| Software Engineer (March 2017 - now) Google, Sunnyvale, CA. Personal Data Infrastructure. |
| Software Engineering Intern (June 2015 - September 2015) Google, New York, NY. Search Infrastructure. |
| Software Engineering Intern (June 2014 - September 2014) Google, Los Angeles, CA. YouTube. |
| Publications |
|---|
| Dissertation |
| William Lam Advancing Heuristics for Search over Graphical Models. PhD Thesis, UC Irvine. [pdf] |
| Journal Papers |
| William Lam, Kalev Kask, Javier Larrosa, and Rina Dechter Subproblem Ordering Heuristics for AND/OR Best-First Search. In Journal of Computer and System Sciences, 94, 41-62, March 2018. [pdf | doi] |
| William Lam, Kalev Kask, Javier Larrosa, and Rina Dechter Residual Guided Look-ahead in AND/OR Search for Graphical Models. In Journal of Artificial Intelligence Research, 60, 287-346, October 2017. [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, March 2010. [link] |
| Conference/Workshop Papers |
| William Lam, Kalev Kask, Rina Dechter, and Javier Larrosa On the Impact of Subproblem Orderings on Anytime AND/OR Best-First Search for Lower-Bounds. In Proceedings of ECAI 2016, The Hague, Netherlands, August 2016. [pdf] |
| Rina Dechter, Kalev Kask, William Lam, and Javier Larrosa Look-ahead with Mini-Bucket Heuristics for MPE. In Proceedings of AAAI 2016, Phoenix, AZ, USA, February 2016. [pdf] |
| William Lam, Kalev Kask, and Rina Dechter Empowering Mini-Bucket in Anytime Heuristic Search with Look-Ahead: Preliminary Evaluation. In Proceedings of SoCS 2015, Ein Gedi, the Dead Sea, Israel, June 2015. [pdf] |
| William Lam, Kalev Kask, Rina Dechter, and Alexander Ihler Beyond Static Mini-Bucket: Towards Integrating with Iterative Cost-Shifting Based Dynamic Heuristics. In Proceedings of SoCS 2014 , Prague, Czech Republic, August 2014. [pdf] | Junkyu Lee, William Lam, and Rina Dechter. Benchmark on DAOOPT and GUROBI with the PASCAL2 Inference Challenge Problems. In DISCML 2013 (a workshop of NIPS 2013), Lake Tahoe, NV, USA, December 2013. [pdf] |
| 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] |