Search Results for author: Ruichu Cai

Found 47 papers, 16 papers with code

Causal Discovery from Poisson Branching Structural Causal Model Using High-Order Cumulant with Path Analysis

no code implementations25 Mar 2024 Jie Qiao, Yu Xiang, Zhengming Chen, Ruichu Cai, Zhifeng Hao

Fortunately, in this work, we found that the causal order from $X$ to its child $Y$ is identifiable if $X$ is a root vertex and has at least two directed paths to $Y$, or the ancestor of $X$ with the most directed path to $X$ has a directed path to $Y$ without passing $X$.

Causal Discovery Epidemiology

From Large to Tiny: Distilling and Refining Mathematical Expertise for Math Word Problems with Weakly Supervision

no code implementations21 Mar 2024 Qingwen Lin, Boyan Xu, Zhengting Huang, Ruichu Cai

In light of these challenges, we introduce an innovative two-stage framework that adeptly transfers mathematical Expertise from large to tiny language models.

Math

Debiased Model-based Interactive Recommendation

no code implementations24 Feb 2024 Zijian Li, Ruichu Cai, Haiqin Huang, Sili Zhang, Yuguang Yan, Zhifeng Hao, Zhenghua Dong

Existing model-based interactive recommendation systems are trained by querying a world model to capture the user preference, but learning the world model from historical logged data will easily suffer from bias issues such as popularity bias and sampling bias.

Contrastive Learning Recommendation Systems

Unifying Invariance and Spuriousity for Graph Out-of-Distribution via Probability of Necessity and Sufficiency

no code implementations14 Feb 2024 Xuexin Chen, Ruichu Cai, Kaitao Zheng, Zhifan Jiang, Zhengting Huang, Zhifeng Hao, Zijian Li

Under mild conditions, we show that the invariant subgraph can be extracted by minimizing an upper bound, which is built on the theoretical advance of probability of necessity and sufficiency.

Graph Learning

Feature Attribution with Necessity and Sufficiency via Dual-stage Perturbation Test for Causal Explanation

no code implementations13 Feb 2024 Xuexin Chen, Ruichu Cai, Zhengting Huang, Yuxuan Zhu, Julien Horwood, Zhifeng Hao, Zijian Li, Jose Miguel Hernandez-Lobato

We investigate the problem of explainability in machine learning. To address this problem, Feature Attribution Methods (FAMs) measure the contribution of each feature through a perturbation test, where the difference in prediction is compared under different perturbations. However, such perturbation tests may not accurately distinguish the contributions of different features, when their change in prediction is the same after perturbation. In order to enhance the ability of FAMs to distinguish different features' contributions in this challenging setting, we propose to utilize the probability (PNS) that perturbing a feature is a necessary and sufficient cause for the prediction to change as a measure of feature importance. Our approach, Feature Attribution with Necessity and Sufficiency (FANS), computes the PNS via a perturbation test involving two stages (factual and interventional). In practice, to generate counterfactual samples, we use a resampling-based approach on the observed samples to approximate the required conditional distribution. Finally, we combine FANS and gradient-based optimization to extract the subset with the largest PNS. We demonstrate that FANS outperforms existing feature attribution methods on six benchmarks.

counterfactual

Learning by Doing: An Online Causal Reinforcement Learning Framework with Causal-Aware Policy

no code implementations7 Feb 2024 Ruichu Cai, Siyang Huang, Jie Qiao, Wei Chen, Yan Zeng, Keli Zhang, Fuchun Sun, Yang Yu, Zhifeng Hao

As a key component to intuitive cognition and reasoning solutions in human intelligence, causal knowledge provides great potential for reinforcement learning (RL) agents' interpretability towards decision-making by helping reduce the searching space.

Decision Making Reinforcement Learning (RL)

Where and How to Attack? A Causality-Inspired Recipe for Generating Counterfactual Adversarial Examples

no code implementations21 Dec 2023 Ruichu Cai, Yuxuan Zhu, Jie Qiao, Zefeng Liang, Furui Liu, Zhifeng Hao

By considering the underappreciated causal generating process, first, we pinpoint the source of the vulnerability of DNNs via the lens of causality, then give theoretical results to answer \emph{where to attack}.

counterfactual

Identification of Causal Structure with Latent Variables Based on Higher Order Cumulants

no code implementations19 Dec 2023 Wei Chen, Zhiyi Huang, Ruichu Cai, Zhifeng Hao, Kun Zhang

Despite the emergence of numerous methods aimed at addressing this challenge, they are not fully identified to the structure that two observed variables are influenced by one latent variable and there might be a directed edge in between.

Causal Discovery

Identification of Causal Structure in the Presence of Missing Data with Additive Noise Model

no code implementations19 Dec 2023 Jie Qiao, Zhengming Chen, Jianhua Yu, Ruichu Cai, Zhifeng Hao

With this observation, we aim to investigate the identification problem of learning causal structure from missing data under an additive noise model with different missingness mechanisms, where the `no self-masking missingness' assumption can be eliminated appropriately.

Causal Discovery

Identifying Semantic Component for Robust Molecular Property Prediction

1 code implementation8 Nov 2023 Zijian Li, Zunhong Xu, Ruichu Cai, Zhenhui Yang, Yuguang Yan, Zhifeng Hao, Guangyi Chen, Kun Zhang

Specifically, we first formulate the data generation process from the atom level to the molecular level, where the latent space is split into SI substructures, SR substructures, and SR atom variables.

Molecular Property Prediction Property Prediction

Subspace Identification for Multi-Source Domain Adaptation

1 code implementation NeurIPS 2023 Zijian Li, Ruichu Cai, Guangyi Chen, Boyang Sun, Zhifeng Hao, Kun Zhang

To mitigate the need for these strict assumptions, we propose a subspace identification theory that guarantees the disentanglement of domain-invariant and domain-specific variables under less restrictive constraints regarding domain numbers and transformation properties, thereby facilitating domain adaptation by minimizing the impact of domain shifts on invariant variables.

Disentanglement Domain Adaptation +1

Generalized Independent Noise Condition for Estimating Causal Structure with Latent Variables

no code implementations13 Aug 2023 Feng Xie, Biwei Huang, Zhengming Chen, Ruichu Cai, Clark Glymour, Zhi Geng, Kun Zhang

To address this, we propose a Generalized Independent Noise (GIN) condition for linear non-Gaussian acyclic causal models that incorporate latent variables, which establishes the independence between a linear combination of certain measured variables and some other measured variables.

Generalization bound for estimating causal effects from observational network data

no code implementations8 Aug 2023 Ruichu Cai, Zeqin Yang, Weilin Chen, Yuguang Yan, Zhifeng Hao

To fill this gap, we derive a generalization bound for causal effect estimation in network scenarios by exploiting 1) the reweighting schema based on joint propensity score and 2) the representation learning schema based on Integral Probability Metric (IPM).

Causal Inference Representation Learning

Causal-learn: Causal Discovery in Python

1 code implementation31 Jul 2023 Yujia Zheng, Biwei Huang, Wei Chen, Joseph Ramsey, Mingming Gong, Ruichu Cai, Shohei Shimizu, Peter Spirtes, Kun Zhang

Causal discovery aims at revealing causal relations from observational data, which is a fundamental task in science and engineering.

Causal Discovery

Causal Discovery with Latent Confounders Based on Higher-Order Cumulants

no code implementations31 May 2023 Ruichu Cai, Zhiyi Huang, Wei Chen, Zhifeng Hao, Kun Zhang

In light of the power of the closed-form solution to OICA corresponding to the One-Latent-Component structure, we formulate a way to estimate the mixing matrix using the higher-order cumulants, and further propose the testable One-Latent-Component condition to identify the latent variables and determine causal orders.

Causal Discovery

Structural Hawkes Processes for Learning Causal Structure from Discrete-Time Event Sequences

1 code implementation10 May 2023 Jie Qiao, Ruichu Cai, Siyu Wu, Yu Xiang, Keli Zhang, Zhifeng Hao

Learning causal structure among event types from discrete-time event sequences is a particularly important but challenging task.

A Survey on Causal Reinforcement Learning

no code implementations10 Feb 2023 Yan Zeng, Ruichu Cai, Fuchun Sun, Libo Huang, Zhifeng Hao

While Reinforcement Learning (RL) achieves tremendous success in sequential decision-making problems of many domains, it still faces key challenges of data inefficiency and the lack of interpretability.

Decision Making reinforcement-learning +1

On the Probability of Necessity and Sufficiency of Explaining Graph Neural Networks: A Lower Bound Optimization Approach

no code implementations14 Dec 2022 Ruichu Cai, Yuxuan Zhu, Xuexin Chen, Yuan Fang, Min Wu, Jie Qiao, Zhifeng Hao

To address the non-identifiability of PNS, we resort to a lower bound of PNS that can be optimized via counterfactual estimation, and propose a framework of Necessary and Sufficient Explanation for GNN (NSEG) via optimizing that lower bound.

counterfactual

Long-term Causal Effects Estimation via Latent Surrogates Representation Learning

1 code implementation9 Aug 2022 Ruichu Cai, Weilin Chen, Zeqin Yang, Shu Wan, Chen Zheng, Xiaoqing Yang, Jiecheng Guo

Estimating long-term causal effects based on short-term surrogates is a significant but challenging problem in many real-world applications, e. g., marketing and medicine.

Marketing Representation Learning +1

Time-Series Domain Adaptation via Sparse Associative Structure Alignment: Learning Invariance and Variance

no code implementations7 May 2022 Zijian Li, Ruichu Cai, Jiawei Chen, Yuguan Yan, Wei Chen, Keli Zhang, Junjian Ye

Based on this inspiration, we investigate the domain-invariant unweighted sparse associative structures and the domain-variant strengths of the structures.

Time Series Time Series Analysis +2

REST: Debiased Social Recommendation via Reconstructing Exposure Strategies

1 code implementation13 Jan 2022 Ruichu Cai, Fengzhu Wu, Zijian Li, Jie Qiao, Wei Chen, Yuexing Hao, Hao Gu

By explicitly Reconstructing Exposure STrategies (REST in short), we formalize the recommendation problem as the counterfactual reasoning and propose the debiased social recommendation method.

counterfactual Counterfactual Reasoning +1

Motif Graph Neural Network

1 code implementation30 Dec 2021 Xuexin Chen, Ruichu Cai, Yuan Fang, Min Wu, Zijian Li, Zhifeng Hao

However, standard GNNs in the neighborhood aggregation paradigm suffer from limited discriminative power in distinguishing \emph{high-order} graph structures as opposed to \emph{low-order} structures.

Graph Classification Graph Embedding +2

Domain Adaptation with Invariant Representation Learning: What Transformations to Learn?

1 code implementation NeurIPS 2021 Petar Stojanov, Zijian Li, Mingming Gong, Ruichu Cai, Jaime Carbonell, Kun Zhang

We provide reasoning why when the supports of the source and target data from overlap, any map of $X$ that is fixed across domains may not be suitable for domain adaptation via invariant features.

Representation Learning Transfer Learning +1

CCSL: A Causal Structure Learning Method from Multiple Unknown Environments

1 code implementation18 Nov 2021 Wei Chen, Yunjin Wu, Ruichu Cai, Yueguo Chen, Zhifeng Hao

This method simultaneously integrates the following two tasks: 1) clustering samples of the subjects with the same causal mechanism into different groups; 2) learning causal structures from the samples within the group.

Causal Discovery Clustering +1

TEA: A Sequential Recommendation Framework via Temporally Evolving Aggregations

1 code implementation14 Nov 2021 Zijian Li, Ruichu Cai, Fengzhu Wu, Sili Zhang, Hao Gu, Yuexing Hao, Yuguang

To achieve this, we firstly formalize sequential recommendation as a problem to estimate conditional probability given temporal dynamic heterogeneous graphs and user behavior sequences.

Sequential Recommendation

Transferable Time-Series Forecasting under Causal Conditional Shift

1 code implementation5 Nov 2021 Zijian Li, Ruichu Cai, Tom Z. J Fu, Zhifeng Hao, Kun Zhang

In order to address these challenges, we analyze variational conditional dependencies in time-series data and find that the causal structures are usually stable among domains, and further raise the causal conditional shift assumption.

Domain Adaptation Semi-supervised Domain Adaptation +2

SADGA: Structure-Aware Dual Graph Aggregation Network for Text-to-SQL

1 code implementation NeurIPS 2021 Ruichu Cai, Jinjie Yuan, Boyan Xu, Zhifeng Hao

The key lies in the generalizability of (i) the encoding method to model the question and the database schema and (ii) the question-schema linking method to learn the mapping between words in the question and tables/columns in the database schema.

Ranked #4 on Text-To-SQL on spider (Exact Match Accuracy (Test) metric)

Semantic Parsing Text-To-SQL

Graph Domain Adaptation: A Generative View

no code implementations14 Jun 2021 Ruichu Cai, Fengzhu Wu, Zijian Li, Pengfei Wei, Lingling Yi, Kun Zhang

Based on this assumption, we propose a disentanglement-based unsupervised domain adaptation method for the graph-structured data, which applies variational graph auto-encoders to recover these latent variables and disentangles them via three supervised learning modules.

Disentanglement Graph Classification +2

On the Role of Entropy-based Loss for Learning Causal Structures with Continuous Optimization

1 code implementation5 Jun 2021 Weilin Chen, Jie Qiao, Ruichu Cai, Zhifeng Hao

Causal discovery from observational data is an important but challenging task in many scientific fields.

Causal Discovery

THP: Topological Hawkes Processes for Learning Causal Structure on Event Sequences

no code implementations23 May 2021 Ruichu Cai, Siyu Wu, Jie Qiao, Zhifeng Hao, Keli Zhang, Xi Zhang

We further propose a causal structure learning method on THP in a likelihood framework.

FRITL: A Hybrid Method for Causal Discovery in the Presence of Latent Confounders

no code implementations26 Mar 2021 Wei Chen, Kun Zhang, Ruichu Cai, Biwei Huang, Joseph Ramsey, Zhifeng Hao, Clark Glymour

The first step of our method uses the FCI procedure, which allows confounders and is able to produce asymptotically correct results.

Causal Discovery

Semi-Supervised Disentangled Framework for Transferable Named Entity Recognition

1 code implementation22 Dec 2020 Zhifeng Hao, Di Lv, Zijian Li, Ruichu Cai, Wen Wen, Boyan Xu

In the proposed framework, the domain-specific information is integrated with the domain-specific latent variables by using a domain predictor.

Cross-Lingual NER Domain Adaptation +3

Learning Disentangled Semantic Representation for Domain Adaptation

1 code implementation22 Dec 2020 Ruichu Cai, Zijian Li, Pengfei Wei, Jie Qiao, Kun Zhang, Zhifeng Hao

Different from previous efforts on the entangled feature space, we aim to extract the domain invariant semantic information in the latent disentangled semantic representation (DSR) of the data.

Domain Adaptation

Time Series Domain Adaptation via Sparse Associative Structure Alignment

no code implementations22 Dec 2020 Ruichu Cai, Jiawei Chen, Zijian Li, Wei Chen, Keli Zhang, Junjian Ye, Zhuozhang Li, Xiaoyan Yang, Zhenjie Zhang

To reduce the difficulty in the discovery of causal structure, we relax it to the sparse associative structure and propose a novel sparse associative structure alignment model for domain adaptation.

Domain Adaptation Time Series +1

Generalized Independent Noise Condition for Estimating Latent Variable Causal Graphs

no code implementations NeurIPS 2020 Feng Xie, Ruichu Cai, Biwei Huang, Clark Glymour, Zhifeng Hao, Kun Zhang

Despite its success in certain domains, most existing methods focus on causal relations between observed variables, while in many scenarios the observed ones may not be the underlying causal variables (e. g., image pixels), but are generated by latent causal variables or confounders that are causally related.

Causal Discovery

Causal Discovery with Multi-Domain LiNGAM for Latent Factors

no code implementations19 Sep 2020 Yan Zeng, Shohei Shimizu, Ruichu Cai, Feng Xie, Michio Yamamoto, Zhifeng Hao

In this paper, we propose Multi-Domain Linear Non-Gaussian Acyclic Models for Latent Factors (MD-LiNA), where the causal structure among latent factors of interest is shared for all domains, and we provide its identification results.

Causal Discovery

TAG : Type Auxiliary Guiding for Code Comment Generation

no code implementations ACL 2020 Ruichu Cai, Zhihao Liang, Boyan Xu, Zijian Li, Yuexing Hao, Yao Chen

Existing leading code comment generation approaches with the structure-to-sequence framework ignores the type information of the interpretation of the code, e. g., operator, string, etc.

Code Comment Generation Comment Generation +3

Triad Constraints for Learning Causal Structure of Latent Variables

no code implementations NeurIPS 2019 Ruichu Cai, Feng Xie, Clark Glymour, Zhifeng Hao, Kun Zhang

In this paper, by properly leveraging the non-Gaussianity of the data, we propose to estimate the structure over latent variables with the so-called Triad constraints: we design a form of "pseudo-residual" from three variables, and show that when causal relations are linear and noise terms are non-Gaussian, the causal direction between the latent variables for the three observed variables is identifiable by checking a certain kind of independence relationship.

Disentanglement Challenge: From Regularization to Reconstruction

no code implementations30 Nov 2019 Jie Qiao, Zijian Li, Boyan Xu, Ruichu Cai, Kun Zhang

The challenge of learning disentangled representation has recently attracted much attention and boils down to a competition using a new real world disentanglement dataset (Gondal et al., 2019).

Disentanglement

Causal Mechanism Transfer Network for Time Series Domain Adaptation in Mechanical Systems

no code implementations13 Oct 2019 Zijian Li, Ruichu Cai, Kok Soon Chai, Hong Wei Ng, Hoang Dung Vu, Marianne Winslett, Tom Z. J. Fu, Boyan Xu, Xiaoyan Yang, Zhenjie Zhang

However, the mainstream domain adaptation methods cannot achieve ideal performance on time series data, because most of them focus on static samples and even the existing time series domain adaptation methods ignore the properties of time series data, such as temporal causal mechanism.

Domain Adaptation Fault Detection +2

Causal Discovery with Cascade Nonlinear Additive Noise Models

2 code implementations23 May 2019 Ruichu Cai, Jie Qiao, Kun Zhang, Zhenjie Zhang, Zhifeng Hao

In this work, we propose a cascade nonlinear additive noise model to represent such causal influences--each direct causal relation follows the nonlinear additive noise model but we observe only the initial cause and final effect.

Causal Discovery

Causal Discovery from Discrete Data using Hidden Compact Representation

no code implementations NeurIPS 2018 Ruichu Cai, Jie Qiao, Kun Zhang, Zhenjie Zhang, Zhifeng Hao

In this paper we make an attempt to find a way to solve this problem by assuming a two-stage causal process: the first stage maps the cause to a hidden variable of a lower cardinality, and the second stage generates the effect from the hidden representation.

Causal Discovery

An Encoder-Decoder Framework Translating Natural Language to Database Queries

no code implementations16 Nov 2017 Ruichu Cai, Boyan Xu, Xiaoyan Yang, Zhenjie Zhang, Zijian Li, Zhihao Liang

These techniques help the neural network better focus on understanding semantics of operations in natural language and save the efforts on SQL grammar learning.

Machine Translation Management +2

SADA: A General Framework to Support Robust Causation Discovery with Theoretical Guarantee

no code implementations5 Jul 2017 Ruichu Cai, Zhenjie Zhang, Zhifeng Hao

We theoretically prove that SADA always reduces the scales of problems without sacrifice on accuracy, under the condition of local causal sparsity and reliable conditional independence tests.

Component-Based Distributed Framework for Coherent and Real-Time Video Dehazing

no code implementations7 Sep 2016 Meihua Wang, Jiaming Mai, Yun Liang, Tom Z. J. Fu, Zhenjie Zhang, Ruichu Cai

Traditional dehazing techniques, as a well studied topic in image processing, are now widely used to eliminate the haze effects from individual images.

Decision Making Robot Navigation

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