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Utku Evci

15 accepted papers

2025

Spark Transformer: Reactivating Sparsity in Transformer FFN and Attention

NeurIPS 2025poster

The discovery of the *lazy neuron phenomenon* (Li et al., 2022), where fewer than 10% of the feedforward networks (FFN) parameters in trained Transformers are activated per token, has spurred significant interests in *activation sparsity* for enhancing large model efficiency. While notable progress…

Cited by 0SourceScholar
2025

The Journey Matters: Average Parameter Count over Pre-training Unifies Sparse and Dense Scaling Laws

ICLR 2025poster

Pruning eliminates unnecessary parameters in neural networks; it offers a promising solution to the growing computational demands of large language models (LLMs). While many focus on post-training pruning, sparse pre-training--which combines pruning and pre-training into a single phase--provides a…

Cited by 0SourcePDFScholar
2024

Dynamic Sparse Training with Structured Sparsity

ICLR 2024poster

Dynamic Sparse Training (DST) methods achieve state-of-the-art results in sparse neural network training, matching the generalization of dense models while enabling sparse training and inference. Although the resulting models are highly sparse and theoretically less computationally expensive, achiev…

2024

Scaling Laws for Sparsely-Connected Foundation Models

ICLR 2024spotlight

We explore the impact of parameter sparsity on the scaling behavior of Transformers trained on massive datasets (i.e., "foundation models"), in both vision and language domains. In this setting, we identify the first scaling law describing the relationship between weight sparsity, number of non-zero…

2023

Scaling Vision Transformers to 22 Billion Parameters

ICML 2023oral

The scaling of Transformers has driven breakthrough capabilities for language models. At present, the largest large language models (LLMs) contain upwards of 100B parameters. Vision Transformers (ViT) have introduced the same architecture to image and video modelling, but these have not yet been suc…

Cited by 650SourcePDFScholar
2023

The Dormant Neuron Phenomenon in Deep Reinforcement Learning

ICML 2023oral

In this work we identify the dormant neuron phenomenon in deep reinforcement learning, where an agent's network suffers from an increasing number of inactive neurons, thereby affecting network expressivity. We demonstrate the presence of this phenomenon across a variety of algorithms and environment…

2022

GradMax: Growing Neural Networks using Gradient Information

ICLR 2022poster

The architecture and the parameters of neural networks are often optimized independently, which requires costly retraining of the parameters whenever the architecture is modified. In this work we instead focus on growing the architecture without requiring costly retraining. We present a method that…

2022

Gradient Flow in Sparse Neural Networks and How Lottery Tickets Win

AAAI 2022technical

Sparse Neural Networks (NNs) can match the generalization of dense NNs using a fraction of the compute/storage for inference, and have the potential to enable efficient training. However, naively training unstructured sparse NNs from random initialization results in significantly worse generalizatio…

2022

Head2Toe: Utilizing Intermediate Representations for Better Transfer Learning

ICML 2022oral

Transfer-learning methods aim to improve performance in a data-scarce target domain using a model pretrained on a data-rich source domain. A cost-efficient strategy, linear probing, involves freezing the source model and training a new classification head for the target domain. This strategy is outp…

2022

The State of Sparse Training in Deep Reinforcement Learning

ICML 2022spotlight

The use of sparse neural networks has seen rapid growth in recent years, particularly in computer vision. Their appeal stems largely from the reduced number of parameters required to train and store, as well as in an increase in learning efficiency. Somewhat surprisingly, there have been very few ef…

2021

A Unified Few-Shot Classification Benchmark to Compare Transfer and Meta Learning Approaches

NeurIPS 2021poster

Meta and transfer learning are two successful families of approaches to few-shot learning. Despite highly related goals, state-of-the-art advances in each family are measured largely in isolation of each other. As a result of diverging evaluation norms, a direct or thorough comparison of different a…

Cited by 19SourceScholar
2021

Practical Real Time Recurrent Learning with a Sparse Approximation

ICLR 2021spotlight

Recurrent neural networks are usually trained with backpropagation through time, which requires storing a complete history of network states, and prohibits updating the weights "online" (after every timestep). Real Time Recurrent Learning (RTRL) eliminates the need for history storage and allows for…

Cited by 22SourcePDFScholar
2020

Meta-Dataset: A Dataset of Datasets for Learning to Learn from Few Examples

ICLR 2020poster

Few-shot classification refers to learning a classifier for new classes given only a few examples. While a plethora of models have emerged to tackle it, we find the procedure and datasets that are used to assess their progress lacking. To address this limitation, we propose Meta-Dataset: a new bench…

Cited by 788SourcecodeScholar
2020

Rigging the Lottery: Making All Tickets Winners

ICML 2020poster

Many applications require sparse neural networks due to space or inference time restrictions. There is a large body of work on training dense networks to yield sparse networks for inference, but this limits the size of the largest trainable sparse model to that of the largest trainable dense model.…

2018

Empirical Analysis of the Hessian of Over-Parametrized Neural Networks

ICLR 2018workshop

We study the properties of common loss surfaces through their Hessian matrix. In particular, in the context of deep learning, we empirically show that the spectrum of the Hessian is composed of two parts: (1) the bulk centered near zero, (2) and outliers away from the bulk. We present numerical evid…

Cited by 435SourceScholar