From GusWiki

See also:

• Notebooks, my attempt at a Wikipedia-like guide to my research interests. This includes:
  • basic concepts that could I teach in an introductory class (my notebooks reflect my particular way of thinking about them)
  • ideas of my own

Contents 1 Academic Papers 1.1 Conference Papers 1.2 Posters 2 Half-Baked Ideas 3 Project Proposals 4 Papers for classes 4.1 2004 4.2 2003 4.3 2002 4.4 2001 4.5 2000 4.6 1990's

[edit] Academic Papers

ToDo: links for (abstract, PDF in print, best PDF, code, errata)

[edit] Conference Papers

Gustavo Lacerda, Peter Spirtes, Joseph Ramsey, Patrik O. Hoyer - Discovering Cyclic Causal Models by Independent Components Analysis plenary talk at UAI2008

P. O. Hoyer, A. Hyvärinen, R. Scheines, P. Spirtes, J. Ramsey, G. Lacerda, and S. Shimizu - “Causal discovery of linear acyclic models with arbitrary distributions” Proceedings of the 24th Conference on Uncertainty in Artificial Intelligence (UAI-2008)

Noboru Matsuda, William W. Cohen, Jonathan Sewall, Gustavo Lacerda, and Kenneth R. Koedinger - Evaluating a Simulated Student using Real Students Data for Training and Testing, (AIED2007)

Noboru Matsuda, William W. Cohen, Jonathan Sewall, Gustavo Lacerda, and Kenneth R. Koedinger - Predicting Students’ Performance with SimStudent: Learning Cognitive Skills from Observation (International Conference on User Modeling 2007).

S. Fissaha Adafre, W.R. van Hage, J. Kamps, G. Lacerda de Melo, and M. de Rijke - The University of Amsterdam at CLEF 2004, In: C. Peters and F. Borri, editors, Working Notes for the CLEF 2004 Workshop, pages 91-98, 2004.

I think this paper was a blend of many people's independent projects. My part was building a bilingual Portuguese-English dictionary from a parallel corpus. Since were had a very large corpus, no machine learning, or clever word-alignment algorithms were needed. Instead, I created a score that used index-proximity, cognate, and word-length correlations; and bootstrapped with a hand-made dictionary of 100 word-pairs.

[edit] Posters

Gustavo Lacerda, Peter Spirtes, Joseph Ramsey - Learning causal Structural Equation Models (SEMs) from observational data: the two approaches Presented at the Student Symposium at IPAM GSS2007. Since then, Hoyer has led a project to unify the two approaches in a smooth way. (See above Hoyer et al, UAI2008)

[edit] Half-Baked Ideas

My ideas at the half-bakery (old ones)

[edit] Project Proposals

• A QED Project for Science: The Promises of Computer-Level Formalization (2006)

• Formalizing Science Intuitively (2004)

• Using weak definitions in formal mathematics

[edit] Papers for classes

[edit] 2004

• "Modeling Cognitive Theories of Autism: Interpretations of the Executive Dysfunction Theory"

• "Automatic Bilingual Dictionary Building from a Parallel Corpus". The results were published at Adafre, van Hage, Kamps, Lacerda, de Rijke - "The University of Amsterdam at CLEF 2004"

• with Henrik Nordmark: "Identifying Structure in the Narratives of Portuguese-Speaking Children.": reports on experiments performed with Portuguese children at the Spaarndammer School.

[edit] 2003

• with Samson de Jager: "Comparing Baltag-Moss-Solecki Update Logic with Burrows-Abadi-Needham Logic of Authentication"

• with Dr. Jacques Robin, I gave a lecture about logic in AI, including non-monotonic logic, abduction, referential opacity & modal epistemic logic, and different systems for belief revision (most of the material came from Russell&Norvig)

• independent: "Incenting Honest Reporting of Probability Estimates": a non-trivial problem with a very elegant solution which I didn't know about at the time. Available at http://www.livejournal.com/users/gustavolacerda/40137.html

[edit] 2002

• independent: "An Introduction to Tuning Theory." About the small-integer-ratio theory of consonance, and the tradeoff between just intervals and transposibility: Defined utility measures. I suggest that the perception of consonance will be dependent on the instrument's harmonic series.

[edit] 2001

• independent: "Stochastic Simulation of a Sexual Population with a Sickle-Cell-Anemia like disease", where the simulations show that the frequency of this sometimes-beneficial (heterozygous individuals) allele tends to reach an equilibrium.

• with Dr. Karl Voss: "Using Wavelets for Lossy Data Compression": discusses how to pick a basis, presents evaluation measures, demonstration.

[edit] 2000

• with Paul Jakowski: "Non-Parametric Kernel Density Estimation in a Circular Domain": investigated the distribution of emails over the course of a day and treated the issue of smoothing.

• with Dr. Alexei Ashikhmin: "An efficient algorithm for error-correction in noisy channels": about my work at Bell Labs. On this talk, I explained algebraically why the simple Viterbi algorithm works.

[edit] 1990's

• 1999: with Dr. David Farmer: "On the number of Roots of Polynomials over Finite Fields": simple algebraic number theory applied to a seemingly-unexplored problem, intuitions supported by experiments on the computer.

• 1997: high school Extended Essay: sphere falling in a viscous liquid, where I generalize Stokes Law to account for the effect of walls. An empirical law is observed and partially justified by theory.