Search Results for author: Gen Li

Found 102 papers, 26 papers with code

Ranking-Based At-Risk Student Prediction Using Federated Learning and Differential Features

1 code implementation14 May 2025 Shunsuke Yoneda, Valdemar Švábenský, Gen Li, Daisuke Deguchi, Atsushi Shimada

Such textbooks yield learning log data that have been used in numerous educational data mining (EDM) studies for student behavior analysis and performance prediction.

Federated Learning

Provable Efficiency of Guidance in Diffusion Models for General Data Distribution

no code implementations2 May 2025 Gen Li, Yuchen Jiao

How to analyze the guidance effect beyond these case studies remains an open question.

Single-Agent vs. Multi-Agent LLM Strategies for Automated Student Reflection Assessment

no code implementations8 Apr 2025 Gen Li, Li Chen, Cheng Tang, Valdemar Švábenský, Daisuke Deguchi, Takayoshi Yamashita, Atsushi Shimada

We explore the use of Large Language Models (LLMs) for automated assessment of open-text student reflections and prediction of academic performance.

Dimension-Free Convergence of Diffusion Models for Approximate Gaussian Mixtures

no code implementations7 Apr 2025 Gen Li, Changxiao Cai, Yuting Wei

Diffusion models are distinguished by their exceptional generative performance, particularly in producing high-quality samples through iterative denoising.

Denoising

Improving Diffusion-based Inverse Algorithms under Few-Step Constraint via Learnable Linear Extrapolation

1 code implementation13 Mar 2025 Jiawei Zhang, Ziyuan Liu, Leon Yan, Gen Li, Yuantao Gu

Diffusion models have demonstrated remarkable performance in modeling complex data priors, catalyzing their widespread adoption in solving various inverse problems.

Minimax Optimality of the Probability Flow ODE for Diffusion Models

no code implementations12 Mar 2025 Changxiao Cai, Gen Li

Score-based diffusion models have become a foundational paradigm for modern generative modeling, demonstrating exceptional capability in generating samples from complex high-dimensional distributions.

AR-Diffusion: Asynchronous Video Generation with Auto-Regressive Diffusion

1 code implementation10 Mar 2025 Mingzhen Sun, Weining Wang, Gen Li, Jiawei Liu, Jiahui Sun, Wanquan Feng, Shanshan Lao, Siyu Zhou, Qian He, Jing Liu

To address these issues, we introduce Auto-Regressive Diffusion (AR-Diffusion), a novel model that combines the strengths of auto-regressive and diffusion models for flexible, asynchronous video generation.

Video Generation

A Grid-Forming HVDC Series Tapping Converter Using Extended Techniques of Flex-LCC

no code implementations9 Feb 2025 Qianhao Sun, Ruofan Li, Jichen Wang, Mingchao Xia, Qifang Chen, Meiqi Fan, Gen Li, Xuebo Qiao

This paper discusses an extension technology for the previously proposed Flexible Line-Commutated Converter (Flex LCC) [1].

Minimax-Optimal Multi-Agent Robust Reinforcement Learning

no code implementations27 Dec 2024 Yuchen Jiao, Gen Li

We prove that the proposed algorithm achieves an $\varepsilon$-robust coarse correlated equilibrium (CCE) with a sample complexity (up to log factors) of $\widetilde{O}\left(H^3S\sum_{i=1}^mA_i\min\left\{H, 1/R\right\}/\varepsilon^2\right)$, where $S$ denotes the number of states, $A_i$ is the number of actions of the $i$-th agent, $H$ is the finite horizon length, and $R$ is uncertainty level.

reinforcement-learning Reinforcement Learning

Condense, Don't Just Prune: Enhancing Efficiency and Performance in MoE Layer Pruning

1 code implementation26 Nov 2024 Mingyu Cao, Gen Li, Jie Ji, JiaQi Zhang, Xiaolong Ma, Shiwei Liu, Lu Yin

Mixture-of-Experts (MOE) has garnered significant attention for their ability to scale up neural networks while utilizing the same or even fewer active parameters.

Mixture-of-Experts

Analysis of the impact of heterogeneous platoon for mixed traffic flow: control strategy, fuel consumption and emissions

no code implementations22 Nov 2024 Yunxia Wu, Le Li, Zhihong Yao, Yi Wang, Gen Li, Yangsheng Jiang

Finally, numerical experiments were conducted to calculate the average fuel consumption and pollutant emissions of mixed traffic flow under different spacing control strategies, and the impact of platoon spacing control strategies on traffic flow fuel consumption and pollutant emissions was further analyzed.

Principles of Visual Tokens for Efficient Video Understanding

no code implementations20 Nov 2024 Xinyue Hao, Gen Li, Shreyank N Gowda, Robert B Fisher, Jonathan Huang, Anurag Arnab, Laura Sevilla-Lara

First, we develop an oracle for the value of tokens which exposes a clear Pareto distribution where most tokens have remarkably low value, and just a few carry most of the perceptual information.

Video Understanding

BAMITA: Bayesian Multiple Imputation for Tensor Arrays

1 code implementation30 Oct 2024 Ziren Jiang, Gen Li, Eric F. Lock

For two microbiome applications, it is shown to accurately capture uncertainty in the full microbiome profile at missing timepoints and used to infer trends in species diversity for the population.

Imputation Missing Values

Provable Acceleration for Diffusion Models under Minimal Assumptions

no code implementations30 Oct 2024 Gen Li, Changxiao Cai

Score-based diffusion models, while achieving minimax optimality for sampling, are often hampered by slow sampling speeds due to the high computational burden of score function evaluations.

Statistical Inference for Temporal Difference Learning with Linear Function Approximation

no code implementations21 Oct 2024 Weichen Wu, Gen Li, Yuting Wei, Alessandro Rinaldo

Statistical inference with finite-sample validity for the value function of a given policy in Markov decision processes (MDPs) is crucial for ensuring the reliability of reinforcement learning.

Improved Convergence Rate for Diffusion Probabilistic Models

no code implementations17 Oct 2024 Gen Li, Yuchen Jiao

Score-based diffusion models have achieved remarkable empirical performance in the field of machine learning and artificial intelligence for their ability to generate high-quality new data instances from complex distributions.

DartControl: A Diffusion-Based Autoregressive Motion Model for Real-Time Text-Driven Motion Control

no code implementations7 Oct 2024 Kaifeng Zhao, Gen Li, Siyu Tang

Additionally, the learned motion primitive space allows for precise spatial motion control, which we formulate either as a latent noise optimization problem or as a Markov decision process addressed through reinforcement learning.

Motion Generation Motion Synthesis

SpecSAR-Former: A Lightweight Transformer-based Network for Global LULC Mapping Using Integrated Sentinel-1 and Sentinel-2

no code implementations4 Oct 2024 Hao Yu, Gen Li, Haoyu Liu, Songyan Zhu, Wenquan Dong, Changjian Li

Recent approaches in remote sensing have increasingly focused on multimodal data, driven by the growing availability of diverse earth observation datasets.

Earth Observation Semantic Segmentation

O(d/T) Convergence Theory for Diffusion Probabilistic Models under Minimal Assumptions

no code implementations27 Sep 2024 Gen Li, Yuling Yan

Score-based diffusion models, which generate new data by learning to reverse a diffusion process that perturbs data from the target distribution into noise, have achieved remarkable success across various generative tasks.

Denoising

AEANet: Affinity Enhanced Attentional Networks for Arbitrary Style Transfer

no code implementations23 Sep 2024 Gen Li, Xianqiu Zheng, Yujian Li

To address these issues, we propose affinity-enhanced attentional network, which include the content affinity-enhanced attention (CAEA) module, the style affinity-enhanced attention (SAEA) module, and the hybrid attention (HA) module.

Style Transfer

A Score-Based Density Formula, with Applications in Diffusion Generative Models

no code implementations29 Aug 2024 Gen Li, Yuling Yan

Score-based generative models (SGMs) have revolutionized the field of generative modeling, achieving unprecedented success in generating realistic and diverse content.

Learning Precise Affordances from Egocentric Videos for Robotic Manipulation

no code implementations19 Aug 2024 Gen Li, Nikolaos Tsagkas, Jifei Song, Ruaridh Mon-Williams, Sethu Vijayakumar, Kun Shao, Laura Sevilla-Lara

In this paper, we present a streamlined affordance learning system that encompasses data collection, effective model training, and robot deployment.

Grasp Generation

A Sharp Convergence Theory for The Probability Flow ODEs of Diffusion Models

no code implementations5 Aug 2024 Gen Li, Yuting Wei, Yuejie Chi, Yuxin Chen

Diffusion models, which convert noise into new data instances by learning to reverse a diffusion process, have become a cornerstone in contemporary generative modeling.

Deep Understanding of Soccer Match Videos

no code implementations11 Jul 2024 Shikun Xu, Yandong Zhu, Gen Li, Changhu Wang

Soccer is one of the most popular sport worldwide, with live broadcasts frequently available for major matches.

Data Overfitting for On-Device Super-Resolution with Dynamic Algorithm and Compiler Co-Design

1 code implementation3 Jul 2024 Gen Li, Zhihao Shu, Jie Ji, Minghai Qin, Fatemeh Afghah, Wei Niu, Xiaolong Ma

By splitting videos into chunks and applying a super-resolution (SR) model to overfit each chunk, this scheme of SR models plus video chunks is able to replace traditional video transmission to enhance video quality and transmission efficiency.

Code Generation Super-Resolution

Enabling robots to follow abstract instructions and complete complex dynamic tasks

no code implementations17 Jun 2024 Ruaridh Mon-Williams, Gen Li, Ran Long, Wenqian Du, Chris Lucas

To address these challenges, we present a novel framework that combines Large Language Models (LLMs), a curated Knowledge Base, and Integrated Force and Visual Feedback (IFVF).

Unleashing the Denoising Capability of Diffusion Prior for Solving Inverse Problems

1 code implementation11 Jun 2024 Jiawei Zhang, Jiaxin Zhuang, Cheng Jin, Gen Li, Yuantao Gu

The proposed algorithm, termed ProjDiff, effectively harnesses the prior information and the denoising capability of a pre-trained diffusion model within the optimization framework.

Denoising Image Restoration

Adapting to Unknown Low-Dimensional Structures in Score-Based Diffusion Models

no code implementations23 May 2024 Gen Li, Yuling Yan

This paper investigates score-based diffusion models when the underlying target distribution is concentrated on or near low-dimensional manifolds within the higher-dimensional space in which they formally reside, a common characteristic of natural image distributions.

Denoising

Accelerating Convergence of Score-Based Diffusion Models, Provably

no code implementations6 Mar 2024 Gen Li, Yu Huang, Timofey Efimov, Yuting Wei, Yuejie Chi, Yuxin Chen

Score-based diffusion models, while achieving remarkable empirical performance, often suffer from low sampling speed, due to extensive function evaluations needed during the sampling phase.

Towards a mathematical theory for consistency training in diffusion models

no code implementations12 Feb 2024 Gen Li, Zhihan Huang, Yuting Wei

Consistency models, which were proposed to mitigate the high computational overhead during the sampling phase of diffusion models, facilitate single-step sampling while attaining state-of-the-art empirical performance.

EgoGen: An Egocentric Synthetic Data Generator

no code implementations CVPR 2024 Gen Li, Kaifeng Zhao, Siwei Zhang, Xiaozhong Lyu, Mihai Dusmanu, Yan Zhang, Marc Pollefeys, Siyu Tang

To address this challenge, we introduce EgoGen, a new synthetic data generator that can produce accurate and rich ground-truth training data for egocentric perception tasks.

Human Mesh Recovery Motion Synthesis

A non-asymptotic distributional theory of approximate message passing for sparse and robust regression

no code implementations8 Jan 2024 Gen Li, Yuting Wei

Characterizing the distribution of high-dimensional statistical estimators is a challenging task, due to the breakdown of classical asymptotic theory in high dimension.

regression

Removing Interference and Recovering Content Imaginatively for Visible Watermark Removal

no code implementations22 Dec 2023 Yicheng Leng, Chaowei Fang, Gen Li, Yixiang Fang, Guanbin Li

Visible watermarks, while instrumental in protecting image copyrights, frequently distort the underlying content, complicating tasks like scene interpretation and image editing.

Integrating Fairness and Model Pruning Through Bi-level Optimization

no code implementations15 Dec 2023 Yucong Dai, Gen Li, Feng Luo, Xiaolong Ma, Yongkai Wu

To tackle this challenge, we introduce a novel concept of fair model pruning, which involves developing a sparse model that adheres to fairness criteria.

Fairness Model Compression

One-Shot Open Affordance Learning with Foundation Models

no code implementations CVPR 2024 Gen Li, Deqing Sun, Laura Sevilla-Lara, Varun Jampani

We introduce One-shot Open Affordance Learning (OOAL), where a model is trained with just one example per base object category, but is expected to identify novel objects and affordances.

Watt For What: Rethinking Deep Learning's Energy-Performance Relationship

no code implementations10 Oct 2023 Shreyank N Gowda, Xinyue Hao, Gen Li, Shashank Narayana Gowda, Xiaobo Jin, Laura Sevilla-Lara

Deep learning models have revolutionized various fields, from image recognition to natural language processing, by achieving unprecedented levels of accuracy.

Deep Learning

Outlier Weighed Layerwise Sparsity (OWL): A Missing Secret Sauce for Pruning LLMs to High Sparsity

1 code implementation8 Oct 2023 Lu Yin, You Wu, Zhenyu Zhang, Cheng-Yu Hsieh, Yaqing Wang, Yiling Jia, Gen Li, Ajay Jaiswal, Mykola Pechenizkiy, Yi Liang, Michael Bendersky, Zhangyang Wang, Shiwei Liu

Large Language Models (LLMs), renowned for their remarkable performance across diverse domains, present a challenge when it comes to practical deployment due to their colossal model size.

Network Pruning

STGIN: Spatial-Temporal Graph Interaction Network for Large-scale POI Recommendation

no code implementations5 Sep 2023 Shaohua Liu, Yu Qi, Gen Li, Mingjian Chen, Teng Zhang, Jia Cheng, Jun Lei

Specifically, we construct subgraphs of spatial, temporal, spatial-temporal, and global views respectively to precisely characterize the user's interests in various contexts.

graph construction Graph Sampling

DeSRA: Detect and Delete the Artifacts of GAN-based Real-World Super-Resolution Models

1 code implementation5 Jul 2023 Liangbin Xie, Xintao Wang, Xiangyu Chen, Gen Li, Ying Shan, Jiantao Zhou, Chao Dong

After detecting the artifact regions, we develop a finetune procedure to improve GAN-based SR models with a few samples, so that they can deal with similar types of artifacts in more unseen real data.

Image Super-Resolution

Referenceless User Controllable Semantic Image Synthesis

1 code implementation18 Jun 2023 Jonghyun Kim, Gen Li, Joongkyu Kim

Despite recent progress in semantic image synthesis, complete control over image style remains a challenging problem.

Image Generation

Towards Faster Non-Asymptotic Convergence for Diffusion-Based Generative Models

no code implementations15 Jun 2023 Gen Li, Yuting Wei, Yuxin Chen, Yuejie Chi

Diffusion models, which convert noise into new data instances by learning to reverse a Markov diffusion process, have become a cornerstone in contemporary generative modeling.

Denoising

High-probability sample complexities for policy evaluation with linear function approximation

no code implementations30 May 2023 Gen Li, Weichen Wu, Yuejie Chi, Cong Ma, Alessandro Rinaldo, Yuting Wei

This paper is concerned with the problem of policy evaluation with linear function approximation in discounted infinite horizon Markov decision processes.

The Curious Price of Distributional Robustness in Reinforcement Learning with a Generative Model

no code implementations NeurIPS 2023 Laixi Shi, Gen Li, Yuting Wei, Yuxin Chen, Matthieu Geist, Yuejie Chi

Assuming access to a generative model that draws samples based on the nominal MDP, we characterize the sample complexity of RMDPs when the uncertainty set is specified via either the total variation (TV) distance or $\chi^2$ divergence.

Reinforcement Learning (RL)

Provable Identifiability of Two-Layer ReLU Neural Networks via LASSO Regularization

no code implementations7 May 2023 Gen Li, Ganghua Wang, Jie Ding

In this paper, the territory of LASSO is extended to two-layer ReLU neural networks, a fashionable and powerful nonlinear regression model.

regression Variable Selection +1

Minimax-Optimal Reward-Agnostic Exploration in Reinforcement Learning

no code implementations14 Apr 2023 Gen Li, Yuling Yan, Yuxin Chen, Jianqing Fan

This paper studies reward-agnostic exploration in reinforcement learning (RL) -- a scenario where the learner is unware of the reward functions during the exploration stage -- and designs an algorithm that improves over the state of the art.

Offline RL reinforcement-learning +2

LOCATE: Localize and Transfer Object Parts for Weakly Supervised Affordance Grounding

1 code implementation CVPR 2023 Gen Li, Varun Jampani, Deqing Sun, Laura Sevilla-Lara

A key step to acquire this skill is to identify what part of the object affords each action, which is called affordance grounding.

Object

Towards High-Quality and Efficient Video Super-Resolution via Spatial-Temporal Data Overfitting

2 code implementations CVPR 2023 Gen Li, Jie Ji, Minghai Qin, Wei Niu, Bin Ren, Fatemeh Afghah, Linke Guo, Xiaolong Ma

To reconcile such, we propose a novel method for high-quality and efficient video resolution upscaling tasks, which leverages the spatial-temporal information to accurately divide video into chunks, thus keeping the number of chunks as well as the model size to minimum.

Video Super-Resolution

Approximate message passing from random initialization with applications to $\mathbb{Z}_{2}$ synchronization

no code implementations7 Feb 2023 Gen Li, Wei Fan, Yuting Wei

This paper is concerned with the problem of reconstructing an unknown rank-one matrix with prior structural information from noisy observations.

Fast Computation of Optimal Transport via Entropy-Regularized Extragradient Methods

no code implementations30 Jan 2023 Gen Li, Yanxi Chen, Yu Huang, Yuejie Chi, H. Vincent Poor, Yuxin Chen

Efficient computation of the optimal transport distance between two distributions serves as an algorithm subroutine that empowers various applications.

Efficient and Accurate Quantized Image Super-Resolution on Mobile NPUs, Mobile AI & AIM 2022 challenge: Report

2 code implementations7 Nov 2022 Andrey Ignatov, Radu Timofte, Maurizio Denna, Abdel Younes, Ganzorig Gankhuyag, Jingang Huh, Myeong Kyun Kim, Kihwan Yoon, Hyeon-Cheol Moon, Seungho Lee, Yoonsik Choe, Jinwoo Jeong, Sungjei Kim, Maciej Smyl, Tomasz Latkowski, Pawel Kubik, Michal Sokolski, Yujie Ma, Jiahao Chao, Zhou Zhou, Hongfan Gao, Zhengfeng Yang, Zhenbing Zeng, Zhengyang Zhuge, Chenghua Li, Dan Zhu, Mengdi Sun, Ran Duan, Yan Gao, Lingshun Kong, Long Sun, Xiang Li, Xingdong Zhang, Jiawei Zhang, Yaqi Wu, Jinshan Pan, Gaocheng Yu, Jin Zhang, Feng Zhang, Zhe Ma, Hongbin Wang, Hojin Cho, Steve Kim, Huaen Li, Yanbo Ma, Ziwei Luo, Youwei Li, Lei Yu, Zhihong Wen, Qi Wu, Haoqiang Fan, Shuaicheng Liu, Lize Zhang, Zhikai Zong, Jeremy Kwon, Junxi Zhang, Mengyuan Li, Nianxiang Fu, Guanchen Ding, Han Zhu, Zhenzhong Chen, Gen Li, Yuanfan Zhang, Lei Sun, Dafeng Zhang, Neo Yang, Fitz Liu, Jerry Zhao, Mustafa Ayazoglu, Bahri Batuhan Bilecen, Shota Hirose, Kasidis Arunruangsirilert, Luo Ao, Ho Chun Leung, Andrew Wei, Jie Liu, Qiang Liu, Dahai Yu, Ao Li, Lei Luo, Ce Zhu, Seongmin Hong, Dongwon Park, Joonhee Lee, Byeong Hyun Lee, Seunggyu Lee, Se Young Chun, Ruiyuan He, Xuhao Jiang, Haihang Ruan, Xinjian Zhang, Jing Liu, Garas Gendy, Nabil Sabor, Jingchao Hou, Guanghui He

While numerous solutions have been proposed for this problem in the past, they are usually not compatible with low-power mobile NPUs having many computational and memory constraints.

Image Super-Resolution

Reconstructing Action-Conditioned Human-Object Interactions Using Commonsense Knowledge Priors

no code implementations6 Sep 2022 Xi Wang, Gen Li, Yen-Ling Kuo, Muhammed Kocabas, Emre Aksan, Otmar Hilliges

We further qualitatively evaluate the effectiveness of our method on real images and demonstrate its generalizability towards interaction types and object categories.

Human-Object Interaction Detection Object

Minimax-Optimal Multi-Agent RL in Markov Games With a Generative Model

no code implementations22 Aug 2022 Gen Li, Yuejie Chi, Yuting Wei, Yuxin Chen

This paper studies multi-agent reinforcement learning in Markov games, with the goal of learning Nash equilibria or coarse correlated equilibria (CCE) sample-optimally.

Multi-agent Reinforcement Learning

A Non-Asymptotic Framework for Approximate Message Passing in Spiked Models

no code implementations5 Aug 2022 Gen Li, Yuting Wei

As two concrete consequences of the proposed analysis recipe: (i) when solving $\mathbb{Z}_2$ synchronization, we predict the behavior of spectrally initialized AMP for up to $O\big(\frac{n}{\mathrm{poly}\log n}\big)$ iterations, showing that the algorithm succeeds without the need of a subsequent refinement stage (as conjectured recently by \citet{celentano2021local}); (ii) we characterize the non-asymptotic behavior of AMP in sparse PCA (in the spiked Wigner model) for a broad range of signal-to-noise ratio.

Real Image Restoration via Structure-preserving Complementarity Attention

no code implementations28 Jul 2022 Yuanfan Zhang, Gen Li, Lei Sun

Since convolutional neural networks perform well in learning generalizable image priors from large-scale data, these models have been widely used in image denoising tasks.

Image Denoising Image Restoration +1

FaceFormer: Scale-aware Blind Face Restoration with Transformers

no code implementations20 Jul 2022 Aijin Li, Gen Li, Lei Sun, Xintao Wang

Blind face restoration usually encounters with diverse scale face inputs, especially in the real world.

Blind Face Restoration Diversity

AnimeSR: Learning Real-World Super-Resolution Models for Animation Videos

1 code implementation14 Jun 2022 Yanze Wu, Xintao Wang, Gen Li, Ying Shan

This paper studies the problem of real-world video super-resolution (VSR) for animation videos, and reveals three key improvements for practical animation VSR.

Video Super-Resolution

VQFR: Blind Face Restoration with Vector-Quantized Dictionary and Parallel Decoder

1 code implementation13 May 2022 YuChao Gu, Xintao Wang, Liangbin Xie, Chao Dong, Gen Li, Ying Shan, Ming-Ming Cheng

Equipped with the VQ codebook as a facial detail dictionary and the parallel decoder design, the proposed VQFR can largely enhance the restored quality of facial details while keeping the fidelity to previous methods.

Blind Face Restoration Decoder +1

NTIRE 2022 Challenge on Efficient Super-Resolution: Methods and Results

2 code implementations11 May 2022 Yawei Li, Kai Zhang, Radu Timofte, Luc van Gool, Fangyuan Kong, Mingxi Li, Songwei Liu, Zongcai Du, Ding Liu, Chenhui Zhou, Jingyi Chen, Qingrui Han, Zheyuan Li, Yingqi Liu, Xiangyu Chen, Haoming Cai, Yu Qiao, Chao Dong, Long Sun, Jinshan Pan, Yi Zhu, Zhikai Zong, Xiaoxiao Liu, Zheng Hui, Tao Yang, Peiran Ren, Xuansong Xie, Xian-Sheng Hua, Yanbo Wang, Xiaozhong Ji, Chuming Lin, Donghao Luo, Ying Tai, Chengjie Wang, Zhizhong Zhang, Yuan Xie, Shen Cheng, Ziwei Luo, Lei Yu, Zhihong Wen, Qi Wu1, Youwei Li, Haoqiang Fan, Jian Sun, Shuaicheng Liu, Yuanfei Huang, Meiguang Jin, Hua Huang, Jing Liu, Xinjian Zhang, Yan Wang, Lingshun Long, Gen Li, Yuanfan Zhang, Zuowei Cao, Lei Sun, Panaetov Alexander, Yucong Wang, Minjie Cai, Li Wang, Lu Tian, Zheyuan Wang, Hongbing Ma, Jie Liu, Chao Chen, Yidong Cai, Jie Tang, Gangshan Wu, Weiran Wang, Shirui Huang, Honglei Lu, Huan Liu, Keyan Wang, Jun Chen, Shi Chen, Yuchun Miao, Zimo Huang, Lefei Zhang, Mustafa Ayazoğlu, Wei Xiong, Chengyi Xiong, Fei Wang, Hao Li, Ruimian Wen, Zhijing Yang, Wenbin Zou, Weixin Zheng, Tian Ye, Yuncheng Zhang, Xiangzhen Kong, Aditya Arora, Syed Waqas Zamir, Salman Khan, Munawar Hayat, Fahad Shahbaz Khan, Dandan Gaoand Dengwen Zhouand Qian Ning, Jingzhu Tang, Han Huang, YuFei Wang, Zhangheng Peng, Haobo Li, Wenxue Guan, Shenghua Gong, Xin Li, Jun Liu, Wanjun Wang, Dengwen Zhou, Kun Zeng, Hanjiang Lin, Xinyu Chen, Jinsheng Fang

The aim was to design a network for single image super-resolution that achieved improvement of efficiency measured according to several metrics including runtime, parameters, FLOPs, activations, and memory consumption while at least maintaining the PSNR of 29. 00dB on DIV2K validation set.

Image Super-Resolution

Settling the Sample Complexity of Model-Based Offline Reinforcement Learning

no code implementations11 Apr 2022 Gen Li, Laixi Shi, Yuxin Chen, Yuejie Chi, Yuting Wei

We demonstrate that the model-based (or "plug-in") approach achieves minimax-optimal sample complexity without burn-in cost for tabular Markov decision processes (MDPs).

Offline RL reinforcement-learning +2

The Efficacy of Pessimism in Asynchronous Q-Learning

no code implementations14 Mar 2022 Yuling Yan, Gen Li, Yuxin Chen, Jianqing Fan

This paper is concerned with the asynchronous form of Q-learning, which applies a stochastic approximation scheme to Markovian data samples.

Q-Learning

Pessimistic Q-Learning for Offline Reinforcement Learning: Towards Optimal Sample Complexity

no code implementations28 Feb 2022 Laixi Shi, Gen Li, Yuting Wei, Yuxin Chen, Yuejie Chi

Offline or batch reinforcement learning seeks to learn a near-optimal policy using history data without active exploration of the environment.

Offline RL Q-Learning +2

SuperStyleNet: Deep Image Synthesis with Superpixel Based Style Encoder

1 code implementation17 Dec 2021 Jonghyun Kim, Gen Li, Cheolkon Jung, Joongkyu Kim

First, we directly extract the style codes from the original image based on superpixels to consider local objects.

Image Generation Superpixels

Breaking the Sample Complexity Barrier to Regret-Optimal Model-Free Reinforcement Learning

no code implementations NeurIPS 2021 Gen Li, Laixi Shi, Yuxin Chen, Yuejie Chi

Achieving sample efficiency in online episodic reinforcement learning (RL) requires optimally balancing exploration and exploitation.

Q-Learning reinforcement-learning +1

Provable Identifiability of ReLU Neural Networks via Lasso Regularization

no code implementations29 Sep 2021 Gen Li, Ganghua Wang, Yuantao Gu, Jie Ding

In this paper, the territory of LASSO is extended to the neural network model, a fashionable and powerful nonlinear regression model.

regression Variable Selection

The Rate of Convergence of Variation-Constrained Deep Neural Networks

no code implementations22 Jun 2021 Gen Li, Jie Ding

To the best of our knowledge, the rate of convergence of neural networks shown by existing works is bounded by at most the order of $n^{-1/4}$ for a sample size of $n$.

Sample-Efficient Reinforcement Learning Is Feasible for Linearly Realizable MDPs with Limited Revisiting

no code implementations NeurIPS 2021 Gen Li, Yuxin Chen, Yuejie Chi, Yuantao Gu, Yuting Wei

The current paper pertains to a scenario with value-based linear representation, which postulates the linear realizability of the optimal Q-function (also called the "linear $Q^{\star}$ problem").

reinforcement-learning Reinforcement Learning (RL)

Adaptive Prototype Learning and Allocation for Few-Shot Segmentation

2 code implementations CVPR 2021 Gen Li, Varun Jampani, Laura Sevilla-Lara, Deqing Sun, Jonghyun Kim, Joongkyu Kim

By integrating the SGC and GPA together, we propose the Adaptive Superpixel-guided Network (ASGNet), which is a lightweight model and adapts to object scale and shape variation.

Clustering Few-Shot Semantic Segmentation +1

Softmax Policy Gradient Methods Can Take Exponential Time to Converge

no code implementations22 Feb 2021 Gen Li, Yuting Wei, Yuejie Chi, Yuxin Chen

The softmax policy gradient (PG) method, which performs gradient ascent under softmax policy parameterization, is arguably one of the de facto implementations of policy optimization in modern reinforcement learning.

Policy Gradient Methods

Is Q-Learning Minimax Optimal? A Tight Sample Complexity Analysis

no code implementations12 Feb 2021 Gen Li, Changxiao Cai, Yuxin Chen, Yuting Wei, Yuejie Chi

This paper addresses these questions for the synchronous setting: (1) when $|\mathcal{A}|=1$ (so that Q-learning reduces to TD learning), we prove that the sample complexity of TD learning is minimax optimal and scales as $\frac{|\mathcal{S}|}{(1-\gamma)^3\varepsilon^2}$ (up to log factor); (2) when $|\mathcal{A}|\geq 2$, we settle the sample complexity of Q-learning to be on the order of $\frac{|\mathcal{S}||\mathcal{A}|}{(1-\gamma)^4\varepsilon^2}$ (up to log factor).

Natural Questions Q-Learning

THE EFFICACY OF L1 REGULARIZATION IN NEURAL NETWORKS

no code implementations1 Jan 2021 Gen Li, Yuantao Gu, Jie Ding

A crucial problem in neural networks is to select the most appropriate number of hidden neurons and obtain tight statistical risk bounds.

The Efficacy of $L_1$ Regularization in Two-Layer Neural Networks

no code implementations2 Oct 2020 Gen Li, Yuantao Gu, Jie Ding

A crucial problem in neural networks is to select the most appropriate number of hidden neurons and obtain tight statistical risk bounds.

Vocal Bursts Valence Prediction

Edge and Identity Preserving Network for Face Super-Resolution

1 code implementation27 Aug 2020 Jonghyun Kim, Gen Li, Inyong Yun, Cheolkon Jung, Joongkyu Kim

In this paper, we propose a novel Edge and Identity Preserving Network for Face SR Network, named as EIPNet, to minimize the distortion by utilizing a lightweight edge block and identity information.

Super-Resolution

Sample Complexity of Asynchronous Q-Learning: Sharper Analysis and Variance Reduction

no code implementations NeurIPS 2020 Gen Li, Yuting Wei, Yuejie Chi, Yuantao Gu, Yuxin Chen

Focusing on a $\gamma$-discounted MDP with state space $\mathcal{S}$ and action space $\mathcal{A}$, we demonstrate that the $\ell_{\infty}$-based sample complexity of classical asynchronous Q-learning --- namely, the number of samples needed to yield an entrywise $\varepsilon$-accurate estimate of the Q-function --- is at most on the order of $\frac{1}{\mu_{\min}(1-\gamma)^5\varepsilon^2}+ \frac{t_{mix}}{\mu_{\min}(1-\gamma)}$ up to some logarithmic factor, provided that a proper constant learning rate is adopted.

Q-Learning

Nonconvex Low-Rank Tensor Completion from Noisy Data

no code implementations NeurIPS 2019 Changxiao Cai, Gen Li, H. Vincent Poor, Yuxin Chen

We study a noisy tensor completion problem of broad practical interest, namely, the reconstruction of a low-rank tensor from highly incomplete and randomly corrupted observations of its entries.

Subspace Estimation from Unbalanced and Incomplete Data Matrices: $\ell_{2,\infty}$ Statistical Guarantees

no code implementations9 Oct 2019 Changxiao Cai, Gen Li, Yuejie Chi, H. Vincent Poor, Yuxin Chen

This paper is concerned with estimating the column space of an unknown low-rank matrix $\boldsymbol{A}^{\star}\in\mathbb{R}^{d_{1}\times d_{2}}$, given noisy and partial observations of its entries.

Unicoder-VL: A Universal Encoder for Vision and Language by Cross-modal Pre-training

no code implementations16 Aug 2019 Gen Li, Nan Duan, Yuejian Fang, Ming Gong, Daxin Jiang, Ming Zhou

We propose Unicoder-VL, a universal encoder that aims to learn joint representations of vision and language in a pre-training manner.

Ranked #5 on Image-to-Text Retrieval on MS COCO (Recall@10 metric)

Image-text matching Image-text Retrieval +6

DABNet: Depth-wise Asymmetric Bottleneck for Real-time Semantic Segmentation

3 code implementations26 Jul 2019 Gen Li, Inyoung Yun, Jonghyun Kim, Joongkyu Kim

As a pixel-level prediction task, semantic segmentation needs large computational cost with enormous parameters to obtain high performance.

Real-Time Semantic Segmentation Segmentation

Theory of Spectral Method for Union of Subspaces-Based Random Geometry Graph

no code implementations25 Jul 2019 Gen Li, Yuantao Gu

Spectral Method is a commonly used scheme to cluster data points lying close to Union of Subspaces by first constructing a Random Geometry Graph, called Subspace Clustering.

Clustering

Compressed Subspace Learning Based on Canonical Angle Preserving Property

no code implementations14 Jul 2019 Yuchen Jiao, Gen Li, Yuantao Gu

In this paper, we prove that random projection with the so-called Johnson-Lindenstrauss (JL) property approximately preserves canonical angles between subspaces with overwhelming probability.

Clustering Dimensionality Reduction

Deep Reason: A Strong Baseline for Real-World Visual Reasoning

no code implementations24 May 2019 Chenfei Wu, Yanzhao Zhou, Gen Li, Nan Duan, Duyu Tang, Xiaojie Wang

This paper presents a strong baseline for real-world visual reasoning (GQA), which achieves 60. 93% in GQA 2019 challenge and won the sixth place.

Visual Reasoning

Unraveling the Veil of Subspace RIP Through Near-Isometry on Subspaces

no code implementations23 May 2019 Xingyu Xv, Gen Li, Yuantao Gu

Subspace Restricted Isometry Property, a newly-proposed concept, has proved to be a useful tool in analyzing the effect of dimensionality reduction algorithms on subspaces.

Clustering Dimensionality Reduction

Rigorous Restricted Isometry Property of Low-Dimensional Subspaces

no code implementations30 Jan 2018 Gen Li, Qinghua Liu, Yuantao Gu

As an analogy to JL Lemma and RIP for sparse vectors, this work allows the use of random projections to reduce the ambient dimension with the theoretical guarantee that the distance between subspaces after compression is well preserved.

compressed sensing Dimensionality Reduction +1

Linear Convergence of An Iterative Phase Retrieval Algorithm with Data Reuse

no code implementations5 Dec 2017 Gen Li, Yuchen Jiao, Yuantao Gu

In this work, we study for the first time, without the independence assumption, the convergence behavior of the randomized Kaczmarz method for phase retrieval.

Retrieval

Image Super-Resolution Using Dense Skip Connections

1 code implementation ICCV 2017 Tong Tong, Gen Li, Xiejie Liu, Qinquan Gao

In this study, we present a novel single-image super-resolution method by introducing dense skip connections in a very deep network.

Computational Efficiency Image Super-Resolution

Active Orthogonal Matching Pursuit for Sparse Subspace Clustering

no code implementations16 Aug 2017 Yanxi Chen, Gen Li, Yuantao Gu

In this letter, we propose a novel Active OMP-SSC, which improves clustering accuracy of OMP-SSC by adaptively updating data points and randomly dropping data points in the OMP process, while still enjoying the low computational complexity of greedy pursuit algorithms.

Clustering

Structural Learning and Integrative Decomposition of Multi-View Data

no code implementations20 Jul 2017 Irina Gaynanova, Gen Li

We call this model SLIDE for Structural Learning and Integrative DEcomposition of multi-view data.

Clustering Dimensionality Reduction

Restricted Isometry Property of Gaussian Random Projection for Finite Set of Subspaces

no code implementations7 Apr 2017 Gen Li, Yuantao Gu

Dimension reduction plays an essential role when decreasing the complexity of solving large-scale problems.

Clustering compressed sensing +2

Phase Transitions of Spectral Initialization for High-Dimensional Nonconvex Estimation

no code implementations21 Feb 2017 Yue M. Lu, Gen Li

We study a spectral initialization method that serves a key role in recent work on estimating signals in nonconvex settings.

Retrieval Vocal Bursts Intensity Prediction

Supervised multiway factorization

1 code implementation11 Sep 2016 Eric F. Lock, Gen Li

We describe a likelihood-based latent variable representation of the CP factorization, in which the latent variables are informed by additional covariates.

Dimensionality Reduction

Direction-Projection-Permutation for High Dimensional Hypothesis Tests

1 code implementation2 Apr 2013 Susan Wei, Chihoon Lee, Lindsay Wichers, Gen Li, J. S. Marron

Motivated by the prevalence of high dimensional low sample size datasets in modern statistical applications, we propose a general nonparametric framework, Direction-Projection-Permutation (DiProPerm), for testing high dimensional hypotheses.

Methodology

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