no code implementations • 31 Oct 2024 • Chenyue Zhang, Shangyuan Liu, Hoi-To Wai, Anthony Man-Cho So
We draw theoretical insights on the optimal graph structure of the bilevel program and show that they agree with the topology in several man-made networks.
1 code implementation • 24 Oct 2024 • Chung-Yiu Yau, Haoming Liu, Hoi-To Wai
Stochastic decentralized optimization algorithms often suffer from issues such as synchronization overhead and intermittent communication.
1 code implementation • 28 May 2024 • Jiaxiang Li, Siliang Zeng, Hoi-To Wai, Chenliang Li, Alfredo Garcia, Mingyi Hong
State-of-the-art techniques such as Reinforcement Learning from Human Feedback (RLHF) often consist of two stages: 1) supervised fine-tuning (SFT), where the model is fine-tuned by learning from human demonstration data; 2) Preference learning, where preference data is used to learn a reward model, which is in turn used by a reinforcement learning (RL) step to fine-tune the model.
no code implementations • 27 May 2024 • Xiaolu Wang, Yuchang Sun, Hoi-To Wai, Jun Zhang
We consider the distributed learning problem with data dispersed across multiple workers under the orchestration of a central server.
no code implementations • 16 May 2024 • Hoang-Son Nguyen, Hoi-To Wai
We propose a detector that certifies whether the partially observed graph signals are low pass filtered, without requiring the graph topology knowledge.
no code implementations • 17 Apr 2024 • Qiang Li, Michal Yemini, Hoi-To Wai
This paper studies the convergence properties of these algorithms in a performative prediction setting, where the data distribution may shift due to the deployed prediction model.
1 code implementation • 16 Apr 2024 • Chung-Yiu Yau, Hoi-To Wai, Parameswaran Raman, Soumajyoti Sarkar, Mingyi Hong
We follow the global contrastive learning loss as introduced in SogCLR, and propose EMC$^2$ which utilizes an adaptive Metropolis-Hastings subroutine to generate hardness-aware negative samples in an online fashion during the optimization.
no code implementations • 10 Sep 2023 • Xiaolu Wang, Cheng Jin, Hoi-To Wai, Yuantao Gu
This paper considers a type of incremental aggregated gradient (IAG) method for large-scale distributed optimization.
no code implementations • 27 Jun 2023 • Hang Liu, Anna Scaglione, Hoi-To Wai
Our analysis shows that the blind matching outcome converges to the result obtained with known graph topologies when the signal sampling size is large and the signal noise is small.
no code implementations • 2 Jun 2023 • Chenyue Zhang, Yiran He, Hoi-To Wai
This paper proposes a blind detection problem for low pass graph signals.
no code implementations • 11 May 2023 • Katsuki Fukumoto, Koki Yamada, Yuichi Tanaka, Hoi-To Wai
In this paper, we formulate a node clustering of time-varying graphs as an optimization problem based on spectral clustering, with a smoothness constraint of the node labels.
no code implementations • 22 Feb 2023 • Aymeric Dieuleveut, Gersende Fort, Eric Moulines, Hoi-To Wai
Stochastic Approximation (SA) is a classical algorithm that has had since the early days a huge impact on signal processing, and nowadays on machine learning, due to the necessity to deal with a large amount of data observed with uncertainties.
no code implementations • 2 Nov 2022 • Chenyue Zhang, Yiran He, Hoi-To Wai
This paper considers learning a product graph from multi-attribute graph signals.
no code implementations • 28 Jul 2022 • Yiran He, Hoi-To Wai
We study a mixture model of filtered low pass graph signals with possibly non-white and low-rank excitation.
1 code implementation • 1 Feb 2022 • Chung-Yiu Yau, Hoi-To Wai
This paper proposes the Doubly Compressed Momentum-assisted stochastic gradient tracking algorithm $\texttt{DoCoM}$ for communication-efficient decentralized optimization.
no code implementations • 14 Oct 2021 • Hoang-Son Nguyen, Yiran He, Hoi-To Wai
The stability of a graph filter characterizes the effect of topology perturbation on the output of a graph filter, a fundamental building block for GCNs.
no code implementations • 9 Oct 2021 • Arjun Ashok Rao, Hoi-To Wai
In this work, we present an empirical analysis on the performance of compressed decentralized stochastic gradient (DSG) algorithms with overparameterized NNs.
no code implementations • 4 Oct 2021 • Boyi Liu, Jiayang Li, Zhuoran Yang, Hoi-To Wai, Mingyi Hong, Yu Marco Nie, Zhaoran Wang
To regulate a social system comprised of self-interested agents, economic incentives are often required to induce a desirable outcome.
no code implementations • 28 Sep 2021 • Yiran He, Hoi-To Wai
For general low pass graph filter, we show that the graph signals can be described by a structured factor model featuring the product between a low-rank plus sparse factor and an unstructured factor.
no code implementations • 28 Jun 2021 • Berkay Turan, Cesar A. Uribe, Hoi-To Wai, Mahnoosh Alizadeh
In this paper, we propose a first-order distributed optimization algorithm that is provably robust to Byzantine failures-arbitrary and potentially adversarial behavior, where all the participating agents are prone to failure.
no code implementations • NeurIPS 2021 • Alain Durmus, Eric Moulines, Alexey Naumov, Sergey Samsonov, Kevin Scaman, Hoi-To Wai
This family of methods arises in many machine learning tasks and is used to obtain approximate solutions of a linear system $\bar{A}\theta = \bar{b}$ for which $\bar{A}$ and $\bar{b}$ can only be accessed through random estimates $\{({\bf A}_n, {\bf b}_n): n \in \mathbb{N}^*\}$.
no code implementations • NeurIPS 2021 • Prashant Khanduri, Siliang Zeng, Mingyi Hong, Hoi-To Wai, Zhaoran Wang, Zhuoran Yang
We focus on bilevel problems where the lower level subproblem is strongly-convex and the upper level objective function is smooth.
no code implementations • 30 Jan 2021 • Alain Durmus, Eric Moulines, Alexey Naumov, Sergey Samsonov, Hoi-To Wai
This paper studies the exponential stability of random matrix products driven by a general (possibly unbounded) state space Markov chain.
no code implementations • 20 Jan 2021 • Yiran He, Hoi-To Wai
Utilizing this observation, we develop a simple detector that answers if a given data set is produced by a first-order lowpass graph filter.
no code implementations • NeurIPS 2020 • Hoi-To Wai, Zhuoran Yang, Zhaoran Wang, Mingyi Hong
This paper studies a gradient temporal difference (GTD) algorithm using neural network (NN) function approximators to minimize the mean squared Bellman error (MSBE).
no code implementations • NeurIPS 2020 • Gersende Fort, Eric Moulines, Hoi-To Wai
The Expectation Maximization (EM) algorithm is of key importance for inference in latent variable models including mixture of regressors and experts, missing observations.
no code implementations • 30 Nov 2020 • Gersende Fort, Eric Moulines, Hoi-To Wai
The Expectation Maximization (EM) algorithm is of key importance for inference in latent variable models including mixture of regressors and experts, missing observations.
no code implementations • 24 Nov 2020 • Gersende Fort, Eric Moulines, Hoi-To Wai
The Expectation Maximization (EM) algorithm is a key reference for inference in latent variable models; unfortunately, its computational cost is prohibitive in the large scale learning setting.
no code implementations • 18 Aug 2020 • Hoi-To Wai
This rate is comparable to the best known performances of SA in a centralized setting with a non-convex potential function.
no code implementations • 4 Aug 2020 • Raksha Ramakrishna, Hoi-To Wai, Anna Scaglione
The notion of graph filters can be used to define generative models for graph data.
no code implementations • 10 Jul 2020 • Mingyi Hong, Hoi-To Wai, Zhaoran Wang, Zhuoran Yang
Bilevel optimization is a class of problems which exhibit a two-level structure, and its goal is to minimize an outer objective function with variables which are constrained to be the optimal solution to an (inner) optimization problem.
no code implementations • 27 May 2020 • Alain Durmus, Pablo Jiménez, Éric Moulines, Salem Said, Hoi-To Wai
This paper analyzes the convergence for a large class of Riemannian stochastic approximation (SA) schemes, which aim at tackling stochastic optimization problems.
no code implementations • 4 Feb 2020 • Maxim Kaledin, Eric Moulines, Alexey Naumov, Vladislav Tadic, Hoi-To Wai
Our bounds show that there is no discrepancy in the convergence rate between Markovian and martingale noise, only the constants are affected by the mixing time of the Markov chain.
no code implementations • 14 Jan 2020 • Tsung-Hui Chang, Mingyi Hong, Hoi-To Wai, Xinwei Zhang, Songtao Lu
In particular, we {provide a selective review} about the recent techniques developed for optimizing non-convex models (i. e., problem classes), processing batch and streaming data (i. e., data types), over the networks in a distributed manner (i. e., communication and computation paradigm).
no code implementations • NeurIPS 2019 • Hoi-To Wai, Mingyi Hong, Zhuoran Yang, Zhaoran Wang, Kexin Tang
Policy evaluation with smooth and nonlinear function approximation has shown great potential for reinforcement learning.
no code implementations • NeurIPS 2019 • Belhal Karimi, Hoi-To Wai, Eric Moulines, Marc Lavielle
To alleviate this problem, Neal and Hinton have proposed an incremental version of the EM (iEM) in which at each iteration the conditional expectation of the latent data (E-step) is updated only for a mini-batch of observations.
no code implementations • 26 Apr 2019 • Michael T. Schaub, Santiago Segarra, Hoi-To Wai
We discuss a variant of `blind' community detection, in which we aim to partition an unobserved network from the observation of a (dynamical) graph signal defined on the network.
no code implementations • 2 Feb 2019 • Belhal Karimi, Blazej Miasojedow, Eric Moulines, Hoi-To Wai
We illustrate these settings with the online EM algorithm and the policy-gradient method for average reward maximization in reinforcement learning.
no code implementations • 16 Jan 2019 • Xiao Fu, Shahana Ibrahim, Hoi-To Wai, Cheng Gao, Kejun Huang
In this work, we propose a stochastic optimization framework for large-scale CPD with constraints/regularizations.
no code implementations • NeurIPS 2018 • Geneviève Robin, Hoi-To Wai, Julie Josse, Olga Klopp, Éric Moulines
In this paper, we introduce a low-rank interaction and sparse additive effects (LORIS) model which combines matrix regression on a dictionary and low-rank design, to estimate main effects and interactions simultaneously.
no code implementations • 5 Sep 2018 • Hoi-To Wai, Santiago Segarra, Asuman E. Ozdaglar, Anna Scaglione, Ali Jadbabaie
The paper shows that communities can be detected by applying a spectral method to the covariance matrix of graph signals.
no code implementations • NeurIPS 2018 • Hoi-To Wai, Zhuoran Yang, Zhaoran Wang, Mingyi Hong
Despite the success of single-agent reinforcement learning, multi-agent reinforcement learning (MARL) remains challenging due to complex interactions between agents.
Multi-agent Reinforcement Learning reinforcement-learning +2
1 code implementation • 31 May 2018 • Hoi-To Wai, Wei Shi, Cesar A. Uribe, Angelia Nedich, Anna Scaglione
This paper studies an acceleration technique for incremental aggregated gradient ({\sf IAG}) method through the use of \emph{curvature} information for solving strongly convex finite sum optimization problems.
no code implementations • 22 Mar 2018 • Hoi-To Wai, Nikolaos M. Freris, Angelia Nedic, Anna Scaglione
We propose and analyze a new stochastic gradient method, which we call Stochastic Unbiased Curvature-aided Gradient (SUCAG), for finite sum optimization problems.
no code implementations • 24 Oct 2017 • Hoi-To Wai, Wei Shi, Angelia Nedic, Anna Scaglione
We propose a new algorithm for finite sum optimization which we call the curvature-aided incremental aggregated gradient (CIAG) method.
no code implementations • 20 Dec 2016 • Hoi-To Wai, Anna Scaglione, Uzi Harush, Baruch Barzel, Amir Leshem
To overcome this challenge, we develop the Robust IDentification of Sparse networks (RIDS) method that reconstructs the GRN from a small number of perturbation experiments.
no code implementations • 5 Dec 2016 • Hoi-To Wai, Jean Lafond, Anna Scaglione, Eric Moulines
The convergence of the proposed algorithm is studied by viewing the decentralized algorithm as an inexact FW algorithm.
no code implementations • 21 Jan 2016 • Hoi-To Wai, Anna Scaglione, Amir Leshem
The model used for the regression is based on the steady state equation in the linear DeGroot model under the influence of stubborn agents, i. e., agents whose opinions are not influenced by their neighbors.
no code implementations • 5 Oct 2015 • Jean Lafond, Hoi-To Wai, Eric Moulines
With a strongly convex stochastic cost and when the optimal solution lies in the interior of the constraint set or the constraint set is a polytope, the regret bound and anytime optimality are shown to be ${\cal O}( \log^3 T / T )$ and ${\cal O}( \log^2 T / T)$, respectively, where $T$ is the number of rounds played.