Search Results for author: Alberto Bernacchia

Found 18 papers, 3 papers with code

Score Normalization for a Faster Diffusion Exponential Integrator Sampler

1 code implementation31 Oct 2023 Guoxuan Xia, Duolikun Danier, Ayan Das, Stathi Fotiadis, Farhang Nabiei, Ushnish Sengupta, Alberto Bernacchia

As a simple fix, we propose to instead reparameterise the score (at inference) by dividing it by the average absolute value of previous score estimates at that time step collected from offline high NFE generations.

Generative Diffusion Models for Radio Wireless Channel Modelling and Sampling

no code implementations10 Aug 2023 Ushnish Sengupta, Chinkuo Jao, Alberto Bernacchia, Sattar Vakili, Da-Shan Shiu

In this paper, we propose a diffusion model based channel sampling approach for rapidly synthesizing channel realizations from limited data.

Image generation with shortest path diffusion

1 code implementation1 Jun 2023 Ayan Das, Stathi Fotiadis, Anil Batra, Farhang Nabiei, FengTing Liao, Sattar Vakili, Da-Shan Shiu, Alberto Bernacchia

We compute the shortest path according to this metric, and we show that it corresponds to a combination of image sharpening, rather than blurring, and noise deblurring.

Deblurring Image Generation

Sample Complexity of Kernel-Based Q-Learning

no code implementations1 Feb 2023 Sing-Yuan Yeh, Fu-Chieh Chang, Chang-Wei Yueh, Pei-Yuan Wu, Alberto Bernacchia, Sattar Vakili

To the best of our knowledge, this is the first result showing a finite sample complexity under such a general model.

Q-Learning Reinforcement Learning (RL)

Delayed Feedback in Kernel Bandits

no code implementations1 Feb 2023 Sattar Vakili, Danyal Ahmed, Alberto Bernacchia, Ciara Pike-Burke

An abstraction of the problem can be formulated as a kernel based bandit problem (also known as Bayesian optimisation), where a learner aims at optimising a kernelized function through sequential noisy observations.

Bayesian Optimisation Recommendation Systems

Improved Convergence Rates for Sparse Approximation Methods in Kernel-Based Learning

no code implementations8 Feb 2022 Sattar Vakili, Jonathan Scarlett, Da-Shan Shiu, Alberto Bernacchia

Kernel-based models such as kernel ridge regression and Gaussian processes are ubiquitous in machine learning applications for regression and optimization.

Gaussian Processes regression

Uniform Generalization Bounds for Overparameterized Neural Networks

no code implementations13 Sep 2021 Sattar Vakili, Michael Bromberg, Jezabel Garcia, Da-Shan Shiu, Alberto Bernacchia

As a byproduct of our results, we show the equivalence between the RKHS corresponding to the NT kernel and its counterpart corresponding to the Mat\'ern family of kernels, showing the NT kernels induce a very general class of models.

Generalization Bounds

Optimal Order Simple Regret for Gaussian Process Bandits

no code implementations NeurIPS 2021 Sattar Vakili, Nacime Bouziani, Sepehr Jalali, Alberto Bernacchia, Da-Shan Shiu

Consider the sequential optimization of a continuous, possibly non-convex, and expensive to evaluate objective function $f$.

Art Analysis

Natural continual learning: success is a journey, not (just) a destination

1 code implementation NeurIPS 2021 Ta-Chu Kao, Kristopher T. Jensen, Gido M. van de Ven, Alberto Bernacchia, Guillaume Hennequin

In contrast, artificial agents are prone to 'catastrophic forgetting' whereby performance on previous tasks deteriorates rapidly as new ones are acquired.

Continual Learning

How to distribute data across tasks for meta-learning?

no code implementations15 Mar 2021 Alexandru Cioba, Michael Bromberg, Qian Wang, Ritwik Niyogi, Georgios Batzolis, Jezabel Garcia, Da-Shan Shiu, Alberto Bernacchia

We show that: 1) If tasks are homogeneous, there is a uniform optimal allocation, whereby all tasks get the same amount of data; 2) At fixed budget, there is a trade-off between number of tasks and number of data points per task, with a unique solution for the optimum; 3) When trained separately, harder task should get more data, at the cost of a smaller number of tasks; 4) When training on a mixture of easy and hard tasks, more data should be allocated to easy tasks.

Few-Shot Image Classification Meta-Learning

Meta-learning with negative learning rates

no code implementations ICLR 2021 Alberto Bernacchia

We study the performance of MAML as a function of the learning rate of the inner loop, where zero learning rate implies that there is no inner loop.

Meta-Learning regression

Optimal allocation of data across training tasks in meta-learning

no code implementations1 Jan 2021 Georgios Batzolis, Alberto Bernacchia, Da-Shan Shiu, Michael Bromberg, Alexandru Cioba

They are tested on benchmarks with a fixed number of data-points for each training task, and this number is usually arbitrary, for example, 5 instances per class in few-shot classification.

Few-Shot Image Classification Meta-Learning +1

Model agnostic meta-learning on trees

no code implementations1 Jan 2021 Jezabel Garcia, Federica Freddi, Jamie McGowan, Tim Nieradzik, Da-Shan Shiu, Ye Tian, Alberto Bernacchia

In meta-learning, the knowledge learned from previous tasks is transferred to new ones, but this transfer only works if tasks are related, and sharing information between unrelated tasks might hurt performance.

Meta-Learning

Cyclic orthogonal convolutions for long-range integration of features

no code implementations NeurIPS Workshop SVRHM 2021 Federica Freddi, Jezabel R Garcia, Michael Bromberg, Sepehr Jalali, Da-Shan Shiu, Alvin Chua, Alberto Bernacchia

We propose a novel architecture that allows flexible information flow between features $z$ and locations $(x, y)$ across the entire image with a small number of layers.

Image Classification Pathfinder

Non-reversible Gaussian processes for identifying latent dynamical structure in neural data

no code implementations NeurIPS 2020 Virginia Rutten, Alberto Bernacchia, Maneesh Sahani, Guillaume Hennequin

Here, we propose a new family of “dynamical” priors over trajectories, in the form of GP covariance functions that express a property shared by most dynamical systems: temporal non-reversibility.

Gaussian Processes Model Selection +1

Exact natural gradient in deep linear networks and its application to the nonlinear case

no code implementations NeurIPS 2018 Alberto Bernacchia, Mate Lengyel, Guillaume Hennequin

Stochastic gradient descent (SGD) remains the method of choice for deep learning, despite the limitations arising for ill-behaved objective functions.

Cannot find the paper you are looking for? You can Submit a new open access paper.