Search Results for author: Zhitang Chen

Found 38 papers, 10 papers with code

Causal Coordinated Concurrent Reinforcement Learning

no code implementations31 Jan 2024 Tim Tse, Isaac Chan, Zhitang Chen

In this work, we propose a novel algorithmic framework for data sharing and coordinated exploration for the purpose of learning more data-efficient and better performing policies under a concurrent reinforcement learning (CRL) setting.

Causal Inference reinforcement-learning +1

Causal Discovery by Kernel Deviance Measures with Heterogeneous Transforms

no code implementations31 Jan 2024 Tim Tse, Zhitang Chen, Shengyu Zhu, Yue Liu

To go about capturing these discrepancies between cause and effect remains to be a challenge and many current state-of-the-art algorithms propose to compare the norms of the kernel mean embeddings of the conditional distributions.

Causal Discovery

Convergence guarantee for consistency models

no code implementations22 Aug 2023 Junlong Lyu, Zhitang Chen, Shoubo Feng

We provide the first convergence guarantees for the Consistency Models (CMs), a newly emerging type of one-step generative models that can generate comparable samples to those generated by Diffusion Models.

Efficient Bayesian Optimization with Deep Kernel Learning and Transformer Pre-trained on Multiple Heterogeneous Datasets

no code implementations9 Aug 2023 Wenlong Lyu, Shoubo Hu, Jie Chuai, Zhitang Chen

Bayesian optimization (BO) is widely adopted in black-box optimization problems and it relies on a surrogate model to approximate the black-box response function.

Bayesian Optimization

Reweighted Interacting Langevin Diffusions: an Accelerated Sampling Methodfor Optimization

no code implementations30 Jan 2023 Junlong Lyu, Zhitang Chen, Wenlong Lyu, Jianye Hao

We proposed a new technique to accelerate sampling methods for solving difficult optimization problems.

Reframed GES with a Neural Conditional Dependence Measure

1 code implementation17 Jun 2022 Xinwei Shen, Shengyu Zhu, Jiji Zhang, Shoubo Hu, Zhitang Chen

In this paper, we revisit the Greedy Equivalence Search (GES) algorithm, which is widely cited as a score-based algorithm for learning the MEC of the underlying causal structure.

Causal Discovery Causal Inference

Out-of-distribution Generalization with Causal Invariant Transformations

no code implementations CVPR 2022 Ruoyu Wang, Mingyang Yi, Zhitang Chen, Shengyu Zhu

In this work, we obviate these assumptions and tackle the OOD problem without explicitly recovering the causal feature.

Out-of-Distribution Generalization

Generalizable Information Theoretic Causal Representation

no code implementations17 Feb 2022 Mengyue Yang, Xinyu Cai, Furui Liu, Xu Chen, Zhitang Chen, Jianye Hao, Jun Wang

It is evidence that representation learning can improve model's performance over multiple downstream tasks in many real-world scenarios, such as image classification and recommender systems.

counterfactual Image Classification +2

Universality of parametric Coupling Flows over parametric diffeomorphisms

no code implementations7 Feb 2022 Junlong Lyu, Zhitang Chen, Chang Feng, Wenjing Cun, Shengyu Zhu, Yanhui Geng, Zhijie Xu, Yongwei Chen

Invertible neural networks based on Coupling Flows CFlows) have various applications such as image synthesis and data compression.

Bayesian Optimization Data Compression +1

Physics Constrained Flow Neural Network for Short-Timescale Predictions in Data Communications Networks

no code implementations23 Dec 2021 Xiangle Cheng, James He, Shihan Xiao, Yingxue Zhang, Zhitang Chen, Pascal Poupart, FengLin Li

Machine learning is gaining growing momentum in various recent models for the dynamic analysis of information flows in data communications networks.

Self-Supervised Learning

Improving OOD Generalization with Causal Invariant Transformations

no code implementations29 Sep 2021 Ruoyu Wang, Mingyang Yi, Shengyu Zhu, Zhitang Chen

In this work, we obviate these assumptions and tackle the OOD problem without explicitly recovering the causal feature.

Informative Robust Causal Representation for Generalizable Deep Learning

no code implementations29 Sep 2021 Mengyue Yang, Furui Liu, Xu Chen, Zhitang Chen, Jianye Hao, Jun Wang

In many real-world scenarios, such as image classification and recommender systems, it is evidence that representation learning can improve model's performance over multiple downstream tasks.

counterfactual Image Classification +2

Contrastive ACE: Domain Generalization Through Alignment of Causal Mechanisms

no code implementations2 Jun 2021 Yunqi Wang, Furui Liu, Zhitang Chen, Qing Lian, Shoubo Hu, Jianye Hao, Yik-Chung Wu

Domain generalization aims to learn knowledge invariant across different distributions while semantically meaningful for downstream tasks from multiple source domains, to improve the model's generalization ability on unseen target domains.

Domain Generalization

Ordering-Based Causal Discovery with Reinforcement Learning

1 code implementation14 May 2021 Xiaoqiang Wang, Yali Du, Shengyu Zhu, Liangjun Ke, Zhitang Chen, Jianye Hao, Jun Wang

It is a long-standing question to discover causal relations among a set of variables in many empirical sciences.

Causal Discovery reinforcement-learning +2

Causal World Models by Unsupervised Deconfounding of Physical Dynamics

no code implementations28 Dec 2020 Minne Li, Mengyue Yang, Furui Liu, Xu Chen, Zhitang Chen, Jun Wang

The capability of imagining internally with a mental model of the world is vitally important for human cognition.

counterfactual

Weakly Supervised Disentangled Generative Causal Representation Learning

1 code implementation6 Oct 2020 Xinwei Shen, Furui Liu, Hanze Dong, Qing Lian, Zhitang Chen, Tong Zhang

This paper proposes a Disentangled gEnerative cAusal Representation (DEAR) learning method under appropriate supervised information.

Disentanglement

Decoder-free Robustness Disentanglement without (Additional) Supervision

no code implementations2 Jul 2020 Yifei Wang, Dan Peng, Furui Liu, Zhenguo Li, Zhitang Chen, Jiansheng Yang

Adversarial Training (AT) is proposed to alleviate the adversarial vulnerability of machine learning models by extracting only robust features from the input, which, however, inevitably leads to severe accuracy reduction as it discards the non-robust yet useful features.

BIG-bench Machine Learning Disentanglement

On Low Rank Directed Acyclic Graphs and Causal Structure Learning

no code implementations10 Jun 2020 Zhuangyan Fang, Shengyu Zhu, Jiji Zhang, Yue Liu, Zhitang Chen, Yangbo He

Despite several advances in recent years, learning causal structures represented by directed acyclic graphs (DAGs) remains a challenging task in high dimensional settings when the graphs to be learned are not sparse.

A Causal Direction Test for Heterogeneous Populations

no code implementations8 Jun 2020 Vahid Partovi Nia, Xinlin Li, Masoud Asgharian, Shoubo Hu, Zhitang Chen, Yanhui Geng

Our simulation result show that the proposed adjustment significantly improves the performance of the causal direction test statistic for heterogeneous data.

Clustering Decision Making

CausalVAE: Structured Causal Disentanglement in Variational Autoencoder

2 code implementations CVPR 2021 Mengyue Yang, Furui Liu, Zhitang Chen, Xinwei Shen, Jianye Hao, Jun Wang

Learning disentanglement aims at finding a low dimensional representation which consists of multiple explanatory and generative factors of the observational data.

counterfactual Disentanglement

A Graph Autoencoder Approach to Causal Structure Learning

3 code implementations18 Nov 2019 Ignavier Ng, Shengyu Zhu, Zhitang Chen, Zhuangyan Fang

Causal structure learning has been a challenging task in the past decades and several mainstream approaches such as constraint- and score-based methods have been studied with theoretical guarantees.

DO-AutoEncoder: Learning and Intervening Bivariate Causal Mechanisms in Images

no code implementations25 Sep 2019 Tianshuo Cong, Dan Peng, Furui Liu, Zhitang Chen

Our experiments demonstrate our method is able to correctly identify the bivariate causal relationship between concepts in images and the representation learned enables a do-calculus manipulation to images, which generates artificial images that might possibly break the physical law depending on where we intervene the causal system.

Adversarial Attack Representation Learning

Causal Discovery by Kernel Intrinsic Invariance Measure

no code implementations2 Sep 2019 Zhitang Chen, Shengyu Zhu, Yue Liu, Tim Tse

We show our algorithm can be reduced to an eigen-decomposition task on a kernel matrix measuring intrinsic deviance/invariance.

Causal Discovery

Asymptotically Optimal One- and Two-Sample Testing with Kernels

no code implementations27 Aug 2019 Shengyu Zhu, Biao Chen, Zhitang Chen, Pengfei Yang

With Sanov's theorem, we derive a sufficient condition for one-sample tests to achieve the optimal error exponent in the universal setting, i. e., for any distribution defining the alternative hypothesis.

Change Detection Two-sample testing +1

Domain Generalization via Multidomain Discriminant Analysis

no code implementations25 Jul 2019 Shoubo Hu, Kun Zhang, Zhitang Chen, Laiwan Chan

Domain generalization (DG) aims to incorporate knowledge from multiple source domains into a single model that could generalize well on unseen target domains.

Domain Generalization Learning Theory

Causal Discovery with Reinforcement Learning

1 code implementation ICLR 2020 Shengyu Zhu, Ignavier Ng, Zhitang Chen

The reward incorporates both the predefined score function and two penalty terms for enforcing acyclicity.

Causal Discovery Combinatorial Optimization +2

Causal Inference and Mechanism Clustering of A Mixture of Additive Noise Models

1 code implementation NeurIPS 2018 Shoubo Hu, Zhitang Chen, Vahid Partovi Nia, Laiwan Chan, Yanhui Geng

The inference of the causal relationship between a pair of observed variables is a fundamental problem in science, and most existing approaches are based on one single causal model.

Causal Inference Clustering

A Kernel Embedding-based Approach for Nonstationary Causal Model Inference

no code implementations23 Sep 2018 Shoubo Hu, Zhitang Chen, Laiwan Chan

Although nonstationary data are more common in the real world, most existing causal discovery methods do not take nonstationarity into consideration.

Causal Discovery

Exponentially Consistent Kernel Two-Sample Tests

no code implementations23 Feb 2018 Shengyu Zhu, Biao Chen, Zhitang Chen

Given two sets of independent samples from unknown distributions $P$ and $Q$, a two-sample test decides whether to reject the null hypothesis that $P=Q$.

Change Detection Vocal Bursts Valence Prediction

Universal Hypothesis Testing with Kernels: Asymptotically Optimal Tests for Goodness of Fit

no code implementations21 Feb 2018 Shengyu Zhu, Biao Chen, Pengfei Yang, Zhitang Chen

We show that two classes of Maximum Mean Discrepancy (MMD) based tests attain this optimality on $\mathbb R^d$, while the quadratic-time Kernel Stein Discrepancy (KSD) based tests achieve the maximum exponential decay rate under a relaxed level constraint.

Two-sample testing

Causal discovery with scale-mixture model for spatiotemporal variance dependencies

no code implementations NeurIPS 2012 Zhitang Chen, Kun Zhang, Laiwan Chan

In conventional causal discovery, structural equation models (SEM) are directly applied to the observed variables, meaning that the causal effect can be represented as a function of the direct causes themselves.

Causal Discovery

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