no code implementations • 8 Feb 2024 • Alejandro de la Concha, Nicolas Vayatis, Argyris Kalogeratos
This paper addresses the multiple two-sample test problem in a graph-structured setting, which is a common scenario in fields such as Spatial Statistics and Neuroscience.
no code implementations • 7 Feb 2024 • Gaëtan Serré, Argyris Kalogeratos, Nicolas Vayatis
In this paper, we introduce a new flow-based method for global optimization of Lipschitz functions, called Stein Boltzmann Sampling (SBS).
1 code implementation • 18 Dec 2023 • Georgios Vardakas, Argyris Kalogeratos, Aristidis Likas
In this work, we focus on the concept of unimodality and propose a flexible cluster definition called locally unimodal cluster.
no code implementations • 3 Nov 2023 • Alejandro de la Concha, Nicolas Vayatis, Argyris Kalogeratos
Quantifying the difference between two probability density functions, $p$ and $q$, using available data, is a fundamental problem in Statistics and Machine Learning.
no code implementations • 28 Sep 2023 • Ioannis Bargiotas, Argyris Kalogeratos, Nicolas Vayatis
First, we estimate the bisecting hyperplanes for each pair of instances and an aggregated rule derived through the Hodges-Lehmann estimator.
no code implementations • 8 Jan 2023 • Alejandro de la Concha, Argyris Kalogeratos, Nicolas Vayatis
Consider each node of a graph to be generating a data stream that is synchronized and observed at near real-time.
no code implementations • 7 Oct 2022 • Anthea Mérida, Argyris Kalogeratos, Mathilde Mougeot
The approach we propose starts with the rigid decision boundaries of a seed Decision Tree (seed DT), which is used to initialize a Neural DT (NDT).
no code implementations • 1 Oct 2022 • Harry Sevi, Matthieu Jonckheere, Argyris Kalogeratos
In this paper, we introduce a new clustering framework, the Parametrized Random Walk Diffusion Kernel Clustering (P-RWDKC), which is suitable for handling both directed and undirected graphs.
no code implementations • 28 May 2022 • Alejandro de la Concha, Nicolas Vayatis, Argyris Kalogeratos
In this paper, we introduce the first -to the best of our knowledge-graph-based extension of this problem, which reads as follows: Suppose each node $v$ of a fixed graph has access to observations coming from two unknown node-specific pdfs, $p_v$ and $q_v$, and the goal is to estimate for each node the likelihood-ratio between both pdfs by also taking into account the information provided by the graph structure.
no code implementations • 7 Mar 2022 • Harry Sevi, Matthieu Jonckheere, Argyris Kalogeratos
In this paper, we present a generalized spectral clustering framework that can address both directed and undirected graphs.
no code implementations • 20 Oct 2021 • Alejandro de la Concha, Argyris Kalogeratos, Nicolas Vayatis
Consider a heterogeneous data stream being generated by the nodes of a graph.
no code implementations • 24 Jun 2020 • Argyris Kalogeratos, Stefano Sarao Mannelli
In this paper we consider the epidemic competition between two generic diffusion processes, where each competing side is represented by a different state of a stochastic process.
no code implementations • 20 Jun 2020 • Anthea Mérida Montes de Oca, Argyris Kalogeratos, Mathilde Mougeot
In our approach, this is realized by progressively relaxing the decision boundaries of the initial decision trees (the RMs) as long as this is beneficial in terms of performance measured on an analyzed dataset.
1 code implementation • 18 Jun 2020 • Alejandro de la Concha, Nicolas Vayatis, Argyris Kalogeratos
This paper addresses the problem of segmenting a stream of graph signals: we aim to detect changes in the mean of a multivariate signal defined over the nodes of a known graph.
no code implementations • 12 Feb 2020 • Mathilde Fekom, Nicolas Vayatis, Argyris Kalogeratos
In this paper we present the Warm-starting Dynamic Thresholding algorithm, developed using dynamic programming, for a variant of the standard online selection problem.
no code implementations • ICML 2020 • Batiste Le Bars, Pierre Humbert, Argyris Kalogeratos, Nicolas Vayatis
This work focuses on the estimation of multiple change-points in a time-varying Ising model that evolves piece-wise constantly.
no code implementations • 20 Sep 2019 • Mathilde Fekom, Nicolas Vayatis, Argyris Kalogeratos
Under the Dynamic Resource Allocation (DRA) model, an administrator has the mission to allocate dynamically a limited budget of resources to the nodes of a network in order to reduce a diffusion process (DP) (e. g. an epidemic).
no code implementations • 15 Jul 2019 • Ioannis Bargiotas, Argyris Kalogeratos, Myrto Limnios, Pierre-Paul Vidal, Damien Ricard, Nicolas Vayatis
In this work, we present the ts-AUC, a non-parametric multivariate two-sample test, which we employ to analyze statokinesigram differences among PS patients that are fallers (PSf) and non-fallers (PSNF).
no code implementations • 12 Feb 2019 • Batiste Le Bars, Argyris Kalogeratos
In this paper we consider the task of detecting abnormal communication volume occurring at node-level in communication networks.
no code implementations • 15 Sep 2017 • Kevin Scaman, Argyris Kalogeratos, Luca Corinzia, Nicolas Vayatis
Information Cascades Model captures dynamical properties of user activity in a social network.
no code implementations • 26 Feb 2016 • Rémi Lemonnier, Kevin Scaman, Argyris Kalogeratos
In this paper, we present a framework for fitting multivariate Hawkes processes for large-scale problems both in the number of events in the observed history $n$ and the number of event types $d$ (i. e. dimensions).
no code implementations • NeurIPS 2012 • Argyris Kalogeratos, Aristidis Likas
The proposed algorithm considers each cluster member as a ''viewer'' and applies a univariate statistic hypothesis test for unimodality (dip-test) on the distribution of the distances between the viewer and the cluster members.