← Search

Sergios Theodoridis

15 accepted papers

2025

Adaptive Kernel Design for Bayesian Optimization Is a Piece of CAKE with LLMs

NeurIPS 2025poster

The efficiency of Bayesian optimization (BO) relies heavily on the choice of the Gaussian process (GP) kernel, which plays a central role in balancing exploration and exploitation under limited evaluation budgets. Traditional BO methods often rely on fixed or heuristic kernel selection strategies, w…

Cited by 0SourcecodeScholar
2024

Cooperative Sensing Via Matrix Factorization of the Partially Received Sample Covariance Matrix

ICASSP 2024accepted

A fundamental problem in cognitive radio is spectrum sensing, which detects the presence of the primary users in a licensed spectrum. To boost the detection performance and robustness, the multiantenna detector has been investigated and various related methods have been developed, e.g., the energy d…

Cited by 0SourceScholar
2024

Masked Autoencoders with Multi-Window Local-Global Attention Are Better Audio Learners

ICLR 2024poster

In this work, we propose a Multi-Window Masked Autoencoder (MW-MAE) fitted with a novel Multi-Window Multi-Head Attention (MW-MHA) module that facilitates the modelling of local-global interactions in every decoder transformer block through attention heads of several distinct local and global window…

Cited by 4SourcePDFScholar
2024

Towards Efficient Modeling and Inference in Multi-Dimensional Gaussian Process State-Space Models

ICASSP 2024accepted

The Gaussian process state-space model (GPSSM) has attracted extensive attention for modeling complex nonlinear dynamical systems. However, the existing GPSSM employs separate Gaussian processes (GPs) for each latent state dimension, leading to escalating computational complexity and parameter proli…

Cited by 0SourceScholar
2023

Interpretable Nonnegative Incoherent Deep Dictionary Learning for FMRI Data Analysis

ICASSP 2023accepted

Extracting information from fMRI data constitutes a broad active area of research. Current techniques still present several limitations; some ignore relevant aspects regarding the brain functioning or lack of interpretability. In an effort to overcome such limitations, we introduce an extension of t…

Cited by 0SourceScholar
2023

Overcoming Posterior Collapse in Variational Autoencoders Via EM-Type Training

ICASSP 2023accepted

Variational autoencoders (VAE) are one of the most prominent deep generative models for learning the underlying statistical distribution of high-dimensional data. However, training VAEs suffers from a severe issue called posterior collapse; that is, the learned posterior distribution collapses to th…

Cited by 0SourceScholar
2022

A Stimuli-Relevant Directed Dependency Index for Time Series

ICASSP 2022accepted

Transfer entropy can to a certain degree assess the direction in addition to the strength of the couplings within dynamic time series. The greater the transfer entropy, the greater the strength of the dependency between time series. In this work, we are interested in quantifying the effect that a gi…

Cited by 0SourceScholar
2021

Local Competition and Stochasticity for Adversarial Robustness in Deep Learning

AISTATS 2021poster

This work addresses adversarial robustness in deep learning by considering deep networks with stochastic local winner-takes-all (LWTA) activations. This type of network units result in sparse representations from each model layer, as the units are organized in blocks where only one unit generates a…

Cited by 21SourcePDFScholar
2020

An Interpretable and Sample Efficient Deep Kernel for Gaussian Process

UAI 2020poster

We propose a novel Gaussian process kernel that takes advantage of a deep neural network (DNN) structure but retains good interpretability. The resulting kernel is capable of addressing four major issues of the previous works of similar art, i.e., the optimality, explainability, model complexity, an…

Cited by 10SourcePDFScholar
2019

Nonparametric Bayesian Deep Networks with Local Competition

ICML 2019oral

The aim of this work is to enable inference of deep networks that retain high accuracy for the least possible model complexity, with the latter deduced from the data during inference. To this end, we revisit deep networks that comprise competing linear units, as opposed to nonlinear units that do no…

2017

Assisted dictionary learning for FMRI data analysis

ICASSP 2017accepted

Extracting information from functional magnetic resonance images (fMRI) has been a major area of research for more than two decades. The goal of this work is to present a new method for the analysis of fMRI data sets, that is capable to incorporate a priori available information, via an efficient op…

Cited by 0SourceScholar
2015

Distributed robust labeling of audio sources in heterogeneous wireless sensor networks

ICASSP 2015accepted

A novel algorithm for distributed labeling of speech sources is proposed. We consider a wireless sensor network comprising devices that are equipped with multiple microphones, which can “hear” a number of speech signals. The labeling task is performed in a decentralized fashion with a new two-step a…

Cited by 0SourceScholar
2015

Pattern classification formulated as a missing data task: The audio genre classification case

ICASSP 2015accepted

This paper presents pattern classification to a predefined set of classes as a missing data task. This is achieved by first augmenting the feature vector of each training pattern with the corresponding binary codeword representing its class. A Restricted Boltzmann Machine (RBM) or a Dictionary Learn…

Cited by 0SourceScholar