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Kimon Fountoulakis

@kfountou.bsky.social

Associate Professor at CS UWaterloo Machine Learning Lab: opallab.ca

1,100 Followers  |  88 Following  |  140 Posts  |  Joined: 14.11.2024  |  2.1079

Latest posts by kfountou.bsky.social on Bluesky

Done.

09.06.2025 15:11 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

I wrote a blog post about it.

Link: medium.com/@kimon.fount...

27.05.2025 18:36 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

2) Can a neural network discover instructions for performing multiplication itself?

The answer to the first question is yes, with high probability and up to some arbitrary, predetermined precision (see the quoted post).

27.05.2025 00:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Learning to Add, Multiply, and Execute Algorithmic Instructions Exactly with Neural Networks Neural networks are known for their ability to approximate smooth functions, yet they fail to generalize perfectly to unseen inputs when trained on discrete operations. Such operations lie at the hear...

Link to the paper: arxiv.org/abs/2502.16763
Link to the repository: github.com/opallab/bina...

26.05.2025 03:21 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Learning to execute arithmetic exactly, with high probability, can be quite expensive. In the plot, 'ensemble complexity' refers to the number of independently trained models required to achieve exact learning with high probability. ell is the number of bits per number in the input.

26.05.2025 03:21 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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New paper: Learning to Add, Multiply, and Execute Algorithmic Instructions Exactly with Neural Networks

26.05.2025 03:21 โ€” ๐Ÿ‘ 5    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 1
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Learning to execute arithmetic exactly, with high probability, can be quite expensive. In the plot, 'ensemble complexity' refers to the number of independently trained models required to achieve exact learning with high probability. ell is the number of bits per number in the input.

26.05.2025 03:19 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Edinburgh Tram Inquiry - Wikipedia

I never understood the point of trams. They're slow and expensive. I've been to two cities that built them while I was there, Edinburgh and Athens, and in both cases, the projects were born out of corruption. Especially in Edinburgh, it was a disaster. en.wikipedia.org/wiki/Edinbur...

21.05.2025 14:39 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Thanks, the connection to formal languages is quite interesting. I have a section in the repo regarding formal languages but it's small mainly because it's not a topic that I am familiar with. I will add them!

17.05.2025 11:49 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Update, 14 empirical papers added!

16.05.2025 17:26 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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The SIAM Conference on Optimization 2026 will be in Edinburgh! I donโ€™t really work on optimization anymore (at least not directly), but itโ€™s cool to see a major optimization conference taking place where I did my PhD.

15.05.2025 13:32 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Currently NeurIPS has 21390 submissions. The final number last year was 15671.

Observation made by my student George Giapitzakis.

11.05.2025 14:31 โ€” ๐Ÿ‘ 5    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Got a pin this morning

Einstein problem: en.wikipedia.org/wiki/Einstei...

07.05.2025 03:23 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Our new work on scaling laws that includes compute, model size, and number of samples. The analysis involves an extremely fine-grained analysis of online sgd built up over the last 8 years of understanding sgd on simple toy models (tensors, single index models, multi index model)

05.05.2025 17:08 โ€” ๐Ÿ‘ 5    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Hey, I definitely predicted this correctly.

01.05.2025 20:42 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

ChatGPT gives me the ability to expand my search capabilities on topics that I can only roughly describe, or even illustrate with a figure, when I donโ€™t know the exact keywords to use in a Google search.

01.05.2025 17:58 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Positional Attention: Expressivity and Learnability of Algorithmic Computation There is a growing interest in the ability of neural networks to execute algorithmic tasks (e.g., arithmetic, summary statistics, and sorting). The goal of this work is to better understand the role o...

That's a comprehensive study on the expressivity for parallel algorithms, their in- and out-of-distribution learnability, and it includes a lot of experiments.

link: arxiv.org/abs/2410.01686

01.05.2025 13:22 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Positional Attention is accepted at ICML 2025! Thanks to all co-authors for the hard work (64 pages). If youโ€™d like to read the paper, check the quoted post.

01.05.2025 13:22 โ€” ๐Ÿ‘ 7    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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NeurIPS 2026 in the Cyclades. Just saying.

29.04.2025 18:12 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Wait, isn't that America?

28.04.2025 17:29 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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A generalized neural tangent kernel for surrogate gradient learning State-of-the-art neural network training methods depend on the gradient of the network function. Therefore, they cannot be applied to networks whose activation functions do not have useful...

This is different from simply replacing the discontinuous activation in the neural network with a continuous one and then using standard NTK.

link: openreview.net/forum?id=kfd...

27.04.2025 00:03 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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A generalized neural tangent kernel for surrogate gradient learning State-of-the-art neural network training methods depend on the gradient of the network function. Therefore, they cannot be applied to networks whose activation functions do not have useful...

They analyze a modified gradient flow, where the Jacobian for the training data uses an approximate derivative of the activation function.

27.04.2025 00:03 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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I enjoyed reading the paper "A Generalized Neural Tangent Kernel for Surrogate Gradient Learning" (Spotlight, NeurIPS 2024).

They extend the NTK framework to activation functions that have finitely many jumps.

27.04.2025 00:03 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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New AI model turns sketches into code | Cheriton School of Computer Science | University of Waterloo Co-developed by alum Ryan Yen, Code Shaping can transform coding beyond the keyboard.

โœ๏ธ Code Shaping, an AI-powered software, allows users to edit their code through sketches like diagrams and graphs ๐Ÿ“ˆ

๐Ÿ† This game-changing platform won the Best Paper Award at #CHI2025.

๐Ÿ”—Read more: uwaterloo.ca/computer-sci...

#UWaterloo #AI

24.04.2025 16:03 โ€” ๐Ÿ‘ 5    ๐Ÿ” 5    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Regarding this particular case, I can read exactly what the code is doing and it seems quite interpretable. I don't have to know some other library to understand the code. It seems to only use basic instructions.

23.04.2025 22:00 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

I prefer more verbose coding, but again, I am only doing prototyping. I find it very annoying when someone's code includes efficient shortcuts that are hard to interpret without a lot of experience.

23.04.2025 22:00 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

To be honest, I find the code by the chat way more readable, exactly because it's verbose. But, I suck at coding, I only prototype ideas...

23.04.2025 16:30 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Deterministic complexity analysis of Hermitian eigenproblems In this work we revisit the arithmetic and bit complexity of Hermitian eigenproblems. We first provide an analysis for the divide-and-conquer tridiagonal eigensolver of Gu and Eisenstat [GE95] in the ...

With my first Bluesky post, I am very pleased to share that my last PhD paper "Deterministic complexity analysis of Hermitian eigenproblems" has been accepted in ICALP 2025. A preprint is available on Arxiv:
arxiv.org/abs/2410.21550
A bit more info on linkedin: www.linkedin.com/posts/aleksa...

14.04.2025 17:25 โ€” ๐Ÿ‘ 4    ๐Ÿ” 2    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

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