5 code implementations • 20 Jun 2016 • Andreas Themelis, Lorenzo Stella, Panagiotis Patrinos
Extending previous results we show that, despite being nonsmooth for fully nonconvex problems, the FBE still enjoys favorable first- and second-order properties which are key for the convergence results of ZeroFPR.
Optimization and Control 90C06, 90C25, 90C26, 90C53, 49J52, 49J53
1 code implementation • 20 May 2020 • Andreas Themelis, Lorenzo Stella, Panagiotis Patrinos
Although the performance of popular optimization algorithms such as Douglas-Rachford splitting (DRS) and the ADMM is satisfactory in small and well-scaled problems, ill conditioning and problem size pose a severe obstacle to their reliable employment.
Optimization and Control 90C06, 90C25, 90C26, 49J52, 49J53
2 code implementations • 27 Apr 2016 • Lorenzo Stella, Andreas Themelis, Panagiotis Patrinos
We propose an algorithmic scheme that enjoys the same global convergence properties of FBS when the problem is convex, or when the objective function possesses the Kurdyka-{\L}ojasiewicz property at its critical points.
Optimization and Control
1 code implementation • 6 Oct 2020 • Ben Hermans, Andreas Themelis, Panagiotis Patrinos
The resulting implementation is shown to be extremely robust in numerical simulations, solving all of the Maros-Meszaros problems and finding a stationary point for most of the nonconvex QPs in the Cutest test set.
Optimization and Control 90C05, 90C20, 90C26, 49J53, 49M15
3 code implementations • 24 Jun 2019 • Puya Latafat, Andreas Themelis, Panagiotis Patrinos
This paper analyzes block-coordinate proximal gradient methods for minimizing the sum of a separable smooth function and a (nonseparable) nonsmooth function, both of which are allowed to be nonconvex.
Optimization and Control 90C06, 90C25, 90C26, 49J52, 49J53
2 code implementations • 11 Jan 2023 • Puya Latafat, Andreas Themelis, Lorenzo Stella, Panagiotis Patrinos
Backtracking linesearch is the de facto approach for minimizing continuously differentiable functions with locally Lipschitz gradient.
1 code implementation • 16 Feb 2021 • Francesco Tonin, Arun Pandey, Panagiotis Patrinos, Johan A. K. Suykens
Detecting out-of-distribution (OOD) samples is an essential requirement for the deployment of machine learning systems in the real world.
Out-of-Distribution Detection Out of Distribution (OOD) Detection
1 code implementation • 23 Jul 2022 • Qinghua Tao, Francesco Tonin, Panagiotis Patrinos, Johan A. K. Suykens
In our method, the dual variables, playing the role of hidden features, are shared by all views to construct a common latent space, coupling the views by learning projections from view-specific spaces.
1 code implementation • ICLR 2022 • Thomas Pethick, Puya Latafat, Panagiotis Patrinos, Olivier Fercoq, Volkan Cevher
This paper introduces a new extragradient-type algorithm for a class of nonconvex-nonconcave minimax problems.
1 code implementation • 22 Feb 2023 • Francesco Tonin, Qinghua Tao, Panagiotis Patrinos, Johan A. K. Suykens
Principal Component Analysis (PCA) and its nonlinear extension Kernel PCA (KPCA) are widely used across science and industry for data analysis and dimensionality reduction.
1 code implementation • 9 Jun 2023 • Francesco Tonin, Alex Lambert, Panagiotis Patrinos, Johan A. K. Suykens
The goal of this paper is to revisit Kernel Principal Component Analysis (KPCA) through dualization of a difference of convex functions.
1 code implementation • 30 Nov 2023 • Puya Latafat, Andreas Themelis, Panagiotis Patrinos
Building upon recent works on linesearch-free adaptive proximal gradient methods, this paper proposes AdaPG$^{\pi, r}$, a framework that unifies and extends existing results by providing larger stepsize policies and improved lower bounds.
1 code implementation • 4 Aug 2019 • Masoud Ahookhosh, Le Thi Khanh Hien, Nicolas Gillis, Panagiotis Patrinos
We introduce and analyze BPALM and A-BPALM, two multi-block proximal alternating linearized minimization algorithms using Bregman distances for solving structured nonconvex problems.
Optimization and Control Numerical Analysis Numerical Analysis
no code implementations • ICML 2020 • Le Thi Khanh Hien, Nicolas Gillis, Panagiotis Patrinos
We propose inertial versions of block coordinate descent methods for solving non-convex non-smooth composite optimization problems.
1 code implementation • 28 May 2019 • Masoud Ahookhosh, Andreas Themelis, Panagiotis Patrinos
We introduce Bella, a locally superlinearly convergent Bregman forward-backward splitting method for minimizing the sum of two nonconvex functions, one of which satisfying a relative smoothness condition and the other one possibly nonsmooth.
Optimization and Control 90C06, 90C25, 90C26, 49J52, 49J53
1 code implementation • 22 Sep 2016 • Andreas Themelis, Panagiotis Patrinos
As a result, SuperMann enhances and robustifies all operator splitting schemes for structured convex optimization, overcoming their well known sensitivity to ill conditioning.
Optimization and Control 47H09, 90C25, 90C53, 65K15
no code implementations • 25 Nov 2020 • Francesco Tonin, Panagiotis Patrinos, Johan A. K. Suykens
We introduce Constr-DRKM, a deep kernel method for the unsupervised learning of disentangled data representations.
no code implementations • 4 Mar 2021 • Peter Coppens, Panagiotis Patrinos
In this paper we introduce a novel approach to distributionally robust optimal control that supports online learning of the ambiguity set, while guaranteeing recursive feasibility.
no code implementations • 15 Mar 2021 • Miguel Simões, Andreas Themelis, Panagiotis Patrinos
Lasry-Lions envelopes can also be seen as an "intermediate" between a given function and its convex envelope, and we make use of this property to develop a method that builds a sequence of approximate subproblems that are easier to solve than the original problem.
1 code implementation • 9 Jul 2021 • Le Thi Khanh Hien, Duy Nhat Phan, Nicolas Gillis, Masoud Ahookhosh, Panagiotis Patrinos
In this paper, we consider a class of nonsmooth nonconvex optimization problems whose objective is the sum of a block relative smooth function and a proper and lower semicontinuous block separable function.
no code implementations • 27 Jun 2022 • Mathijs Schuurmans, Alexander Katriniok, Christopher Meissen, H. Eric Tseng, Panagiotis Patrinos
We present a case study applying learning-based distributionally robust model predictive control to highway motion planning under stochastic uncertainty of the lane change behavior of surrounding road users.
no code implementations • 17 Jul 2022 • Pourya Behmandpoor, Puya Latafat, Andreas Themelis, Marc Moonen, Panagiotis Patrinos
We introduce SPIRAL, a SuPerlinearly convergent Incremental pRoximal ALgorithm, for solving nonconvex regularized finite sum problems under a relative smoothness assumption.
no code implementations • 12 Aug 2022 • Jean Pierre Allamaa, Panagiotis Patrinos, Herman Van der Auweraer, Tong Duy Son
In this work, we propose a sim2real method to transfer and adapt a nonlinear model predictive controller (NMPC) from simulation to the real target system based on executable digital twin (xDT).
1 code implementation • 31 Jan 2023 • Sonny Achten, Francesco Tonin, Panagiotis Patrinos, Johan A. K. Suykens
We present a deep Graph Convolutional Kernel Machine (GCKM) for semi-supervised node classification in graphs.
1 code implementation • 17 Feb 2023 • Thomas Pethick, Olivier Fercoq, Puya Latafat, Panagiotis Patrinos, Volkan Cevher
This paper introduces a family of stochastic extragradient-type algorithms for a class of nonconvex-nonconcave problems characterized by the weak Minty variational inequality (MVI).
no code implementations • 16 Mar 2023 • Mathijs Schuurmans, Panagiotis Patrinos
We present a novel framework for distributionally robust optimization (DRO), called cost-aware DRO (CADRO).
no code implementations • 12 Jun 2023 • Qinghua Tao, Francesco Tonin, Panagiotis Patrinos, Johan A. K. Suykens
We describe a nonlinear extension of the matrix Singular Value Decomposition through asymmetric kernels, namely KSVD.
no code implementations • 12 Jun 2023 • Francesco Tonin, Panagiotis Patrinos, Johan A. K. Suykens
In the context of deep learning with kernel machines, the deep Restricted Kernel Machine (DRKM) framework allows multiple levels of kernel PCA (KPCA) and Least-Squares Support Vector Machines (LSSVM) to be combined into a deep architecture using visible and hidden units.
no code implementations • 8 Nov 2023 • Pourya Behmandpoor, Marc Moonen, Panagiotis Patrinos
Distributed optimization has experienced a significant surge in interest due to its wide-ranging applications in distributed learning and adaptation.
no code implementations • 8 Nov 2023 • Pourya Behmandpoor, Panagiotis Patrinos, Marc Moonen
The optimization algorithm aims to optimize the on-off status of users in a time-sharing problem to satisfy their utility demands in expectation.
no code implementations • 21 Dec 2023 • Jia Wang, Leander Hemelhof, Ivan Markovsky, Panagiotis Patrinos
This paper studies data-driven iterative learning control (ILC) for linear time-invariant (LTI) systems with unknown dynamics, output disturbances and input box-constraints.
no code implementations • 12 Jan 2024 • Jean Pierre Allamaa, Panagiotis Patrinos, Toshiyuki Ohtsuka, Tong Duy Son
The autonomous driving industry is continuously dealing with more safety-critical scenarios, and nonlinear model predictive control (NMPC) is a powerful control strategy for handling such situations.
no code implementations • 9 Feb 2024 • Konstantinos A. Oikonomidis, Emanuel Laude, Puya Latafat, Andreas Themelis, Panagiotis Patrinos
We show that adaptive proximal gradient methods for convex problems are not restricted to traditional Lipschitzian assumptions.