Search Results for author: Ziheng Chen

Found 13 papers, 6 papers with code

Debiasing Machine Unlearning with Counterfactual Examples

no code implementations24 Apr 2024 Ziheng Chen, Jia Wang, Jun Zhuang, Abbavaram Gowtham Reddy, Fabrizio Silvestri, Jin Huang, Kaushiki Nag, Kun Kuang, Xin Ning, Gabriele Tolomei

This bias emerges from two main sources: (1) data-level bias, characterized by uneven data removal, and (2) algorithm-level bias, which leads to the contamination of the remaining dataset, thereby degrading model accuracy.

counterfactual Machine Unlearning

A Lie Group Approach to Riemannian Batch Normalization

1 code implementation17 Mar 2024 Ziheng Chen, Yue Song, Yunmei Liu, Nicu Sebe

Using the deformation concept, we generalize the existing Lie groups on SPD manifolds into three families of parameterized Lie groups.

Action Recognition EEG +1

Riemannian Multinomial Logistics Regression for SPD Neural Networks

1 code implementation18 May 2023 Ziheng Chen, Yue Song, Gaowen Liu, Ramana Rao Kompella, XiaoJun Wu, Nicu Sebe

Besides, our framework offers a novel intrinsic explanation for the most popular LogEig classifier in existing SPD networks.

Action Recognition EEG +2

The Dark Side of Explanations: Poisoning Recommender Systems with Counterfactual Examples

no code implementations30 Apr 2023 Ziheng Chen, Fabrizio Silvestri, Jia Wang, Yongfeng Zhang, Gabriele Tolomei

By reversing the learning process of the recommendation model, we thus develop a proficient greedy algorithm to generate fabricated user profiles and their associated interaction records for the aforementioned surrogate model.

counterfactual Counterfactual Explanation +4

Adaptive Riemannian Metrics on SPD Manifolds

no code implementations26 Mar 2023 Ziheng Chen, Yue Song, Tianyang Xu, Zhiwu Huang, Xiao-Jun Wu, Nicu Sebe

Symmetric Positive Definite (SPD) matrices have received wide attention in machine learning due to their intrinsic capacity of encoding underlying structural correlation in data.

GREASE: Generate Factual and Counterfactual Explanations for GNN-based Recommendations

no code implementations4 Aug 2022 Ziheng Chen, Fabrizio Silvestri, Jia Wang, Yongfeng Zhang, Zhenhua Huang, Hongshik Ahn, Gabriele Tolomei

Although powerful, it is very difficult for a GNN-based recommender system to attach tangible explanations of why a specific item ends up in the list of suggestions for a given user.

counterfactual Graph Classification +1

DreamNet: A Deep Riemannian Network based on SPD Manifold Learning for Visual Classification

no code implementations16 Jun 2022 Rui Wang, Xiao-Jun Wu, Ziheng Chen, Tianyang Xu, Josef Kittler

Image set-based visual classification methods have achieved remarkable performance, via characterising the image set in terms of a non-singular covariance matrix on a symmetric positive definite (SPD) manifold.

RLOP: RL Methods in Option Pricing from a Mathematical Perspective

1 code implementation11 May 2022 Ziheng Chen

Abstract In this work, we build two environments, namely the modified QLBS and RLOP models, from a mathematics perspective which enables RL methods in option pricing through replicating by portfolio.

Position

Riemannian Local Mechanism for SPD Neural Networks

1 code implementation25 Jan 2022 Ziheng Chen, Tianyang Xu, Xiao-Jun Wu, Rui Wang, Zhiwu Huang, Josef Kittler

The Symmetric Positive Definite (SPD) matrices have received wide attention for data representation in many scientific areas.

Classification

ReLAX: Reinforcement Learning Agent eXplainer for Arbitrary Predictive Models

1 code implementation22 Oct 2021 Ziheng Chen, Fabrizio Silvestri, Jia Wang, He Zhu, Hongshik Ahn, Gabriele Tolomei

However, existing CF generation methods either exploit the internals of specific models or depend on each sample's neighborhood, thus they are hard to generalize for complex models and inefficient for large datasets.

counterfactual Decision Making +2

Costly Features Classification using Monte Carlo Tree Search

no code implementations14 Feb 2021 Ziheng Chen, Jin Huang, Hongshik Ahn, Xin Ning

We consider the problem of costly feature classification, where we sequentially select the subset of features to make a balance between the classification error and the feature cost.

Classification General Classification

Item Response Theory based Ensemble in Machine Learning

no code implementations11 Nov 2019 Ziheng Chen, Hongshik Ahn

In this article, we propose a novel probabilistic framework to improve the accuracy of a weighted majority voting algorithm.

BIG-bench Machine Learning

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