Independent

Summary: I trained a 57 million parameter verison of GPT-2 on tens of millions of knight's tour puzzles encoded as linear indices and evaluated whether the model could solve unseen "parberry" puzzles.

Extended Description: "Can large language models generalize?" remains an open question amongst language modeling and artificial intelligence researchers. Investigating this question is quite challenging using LLMs trained on internet corpora.

First, there are methodological debates and uncertainty surrounding the tests of generality. Second, generating out-of-distribution examples is difficult; the internet is vast, and it is hard to verify if evaluations with supposedly out-of-distribution examples are actually out-of-distribution. Third, even if truly novel, out-of-distribution examples can be crafted, interpretability methods are not advanced enough to determine whether the model solved the question using genuine reasoning or mere interpolation / pattern recognition.

Games and puzzles offer a unique opportunity to investigate generalization as they allow us to tightly constrain training and evaluation examples. Motivated by Li et al. (2022) and Ruoss et al. (2022), and after noticing that the Knight's tour had never previously been used as a test of generalization, I trained a GPT-2 variant on tens of millions of knight's tour puzzles encoded as linear indices and evaluated whether the model could solve unseen partial puzzles. I found that models are able to generalize, and the extent of generalization increases for models trained on more data. The version of the model trained on ~25 million Knight's tours could solve 999/1191 parberry puzzles.

Code for generating the training examples, model set up, training, and evaluation can be found here: https://github.com/AsteroidHunter/knightsGPT

Independent

Shellbert is an LLM with a personality that will serve primarily two functions:
1. Automatically finding and posting impact-relevant jobs and opportunities in Tucson Effective Altruism's discord server.
2. Answering questions related to moral/philosophy, economics, global health, animal welfare, and other topics covered in the UArizona course Pathways to Progress.

To better perform these two core tasks, the model will have the capacity to perform web searches, perform simple agentic tasks, and use tools. Besides serving the two goals above, two core motivations behind this project are practical implementation of alignment and personality engineering, as well as remote model deployment.

Shellbert is currently based on the instruction-tuned versions of the Gemma 3n models. The model is hosted on a personal remote server with four NVIDIA 3060's (although, the bot typically uses just a single GPU).

You can find shellbert here: https://github.com/AsteroidHunter/shellbert

Graduate Research Assistant, NEOWISE/NEOS

Summary: We used NEATM (Harris, 1998) and a nonlinear optimization pipeline for modeling and physically characterizing thermally-dominated observations of ~2200 Near-Earth Asteroids (NEAs). This work was done when I was a part of the NEO Surveyor science team, and the results of this investigation were presented at the Planetary Defense Conference (2023).

My three core contributions to this project:
1. Determining the ideal optimization algorithm: I crafted plots and analytical functions to explore the convexity vs. nonconvexity of the loss landscape, independently read about and implemented various nonlinear optimization algorithms from the Scipy and NLOpt libraries, and compared the execution speed and accuracy of the functions implemented. Besides finding the optimal optimization algorithm for the thermal modeling pipeline, a secondary motivation here was testing if the standard errors of the fits could be retrieved from the hessian; while second-order optimization methods are slower, if the standard errors could be retrieved, it would overall reduce modeling time as it is cheaper than running n monte carlo simulations.
2. Pipeline development & validation: I helped parallelize the thermal modeling pipeline using python's multiprocessing package. The other major task was validating the reliability of the pipeline, for which, I created a script that could generate synthetic asteroids using characteristics found in real-world observational data as the prior, and then tested if the results from the new pipeline were close to true diameters and albedos of the synthetic objects.
3. Characterization and analysis of 2200 NEAs: After the pipeline had been sufficiently developed and validated, I ran the algorithm on all the NEA observational data we had, inspected the validity of the fits (and re-fit bad fits using more appropriate parameters), and presented the final results in the form of a talk at the Planetary Defense Conference in Vienna.

Undergraduate Research Assistant, NEOWISE

Summary: We used a scalar optimization algorithm built around NEATM (Harris, 1998) and a markov chain monte carlo algorithm using a thermophysical Model (Wright, 2007) to physically characterize the near-Earth asteroid (99942) Apophis. Our computed effective diameter, albedo, and thermal inertia of the object were in agreement with previous studies on the object, and the final results were published as a first-author paper in the Planetary Science journal. Due to the importance of the object as a potentially hazardous asteroid and since this work was a part of larger planetary defense exercise, the paper also received some some media coverage.