Search Results for author: Zhiwei Xu

Found 49 papers, 8 papers with code

Inference of Dependency Knowledge Graph for Electronic Health Records

no code implementations25 Dec 2023 Zhiwei Xu, Ziming Gan, Doudou Zhou, Shuting Shen, Junwei Lu, Tianxi Cai

The effective analysis of high-dimensional Electronic Health Record (EHR) data, with substantial potential for healthcare research, presents notable methodological challenges.

feature selection

Adaptive parameter sharing for multi-agent reinforcement learning

no code implementations14 Dec 2023 Dapeng Li, Na Lou, Bin Zhang, Zhiwei Xu, Guoliang Fan

Parameter sharing, as an important technique in multi-agent systems, can effectively solve the scalability issue in large-scale agent problems.

Multi-agent Reinforcement Learning reinforcement-learning

Mastering Complex Coordination through Attention-based Dynamic Graph

no code implementations7 Dec 2023 Guangchong Zhou, Zhiwei Xu, Zeren Zhang, Guoliang Fan

The coordination between agents in multi-agent systems has become a popular topic in many fields.

Controlling Large Language Model-based Agents for Large-Scale Decision-Making: An Actor-Critic Approach

no code implementations23 Nov 2023 Bin Zhang, Hangyu Mao, Jingqing Ruan, Ying Wen, Yang Li, Shao Zhang, Zhiwei Xu, Dapeng Li, Ziyue Li, Rui Zhao, Lijuan Li, Guoliang Fan

The remarkable progress in Large Language Models (LLMs) opens up new avenues for addressing planning and decision-making problems in Multi-Agent Systems (MAS).

Decision Making Hallucination +3

IMPUS: Image Morphing with Perceptually-Uniform Sampling Using Diffusion Models

1 code implementation12 Nov 2023 Zhaoyuan Yang, Zhengyang Yu, Zhiwei Xu, Jaskirat Singh, Jing Zhang, Dylan Campbell, Peter Tu, Richard Hartley

We present a diffusion-based image morphing approach with perceptually-uniform sampling (IMPUS) that produces smooth, direct and realistic interpolations given an image pair.

Image Generation Image Morphing

Towards Generalized Multi-stage Clustering: Multi-view Self-distillation

no code implementations29 Oct 2023 Jiatai Wang, Zhiwei Xu, Xin Wang, Tao Li

MVC aims at exploring common semantics and pseudo-labels from multiple views and clustering in a self-supervised manner.

Clustering Contrastive Learning +1

Hierarchical Mutual Information Analysis: Towards Multi-view Clustering in The Wild

no code implementations28 Oct 2023 Jiatai Wang, Zhiwei Xu, Xuewen Yang, Xin Wang

Multi-view clustering (MVC) can explore common semantics from unsupervised views generated by different sources, and thus has been extensively used in applications of practical computer vision.

Clustering

Benign Overfitting and Grokking in ReLU Networks for XOR Cluster Data

no code implementations4 Oct 2023 Zhiwei Xu, Yutong Wang, Spencer Frei, Gal Vardi, Wei Hu

Second, they can undergo a period of classical, harmful overfitting -- achieving a perfect fit to training data with near-random performance on test data -- before transitioning ("grokking") to near-optimal generalization later in training.

Self-supervised Multi-view Clustering in Computer Vision: A Survey

no code implementations18 Sep 2023 Jiatai Wang, Zhiwei Xu, Xuewen Yang, Hailong Li, Bo Li, Xuying Meng

However, as contrastive learning continues to evolve within the field of computer vision, self-supervised learning has also made substantial research progress and is progressively becoming dominant in MVC methods.

Clustering Contrastive Learning +3

TPTU: Large Language Model-based AI Agents for Task Planning and Tool Usage

no code implementations7 Aug 2023 Jingqing Ruan, Yihong Chen, Bin Zhang, Zhiwei Xu, Tianpeng Bao, Guoqing Du, Shiwei Shi, Hangyu Mao, Ziyue Li, Xingyu Zeng, Rui Zhao

With recent advancements in natural language processing, Large Language Models (LLMs) have emerged as powerful tools for various real-world applications.

Language Modelling Large Language Model

Probabilistic and Semantic Descriptions of Image Manifolds and Their Applications

no code implementations6 Jul 2023 Peter Tu, Zhaoyuan Yang, Richard Hartley, Zhiwei Xu, Jing Zhang, Yiwei Fu, Dylan Campbell, Jaskirat Singh, Tianyu Wang

This paper begins with a description of methods for estimating image probability density functions that reflects the observation that such data is usually constrained to lie in restricted regions of the high-dimensional image space-not every pattern of pixels is an image.

PMaF: Deep Declarative Layers for Principal Matrix Features

1 code implementation26 Jun 2023 Zhiwei Xu, Hao Wang, Yanbin Liu, Stephen Gould

We explore two differentiable deep declarative layers, namely least squares on sphere (LESS) and implicit eigen decomposition (IED), for learning the principal matrix features (PMaF).

Towards Understanding Gradient Approximation in Equality Constrained Deep Declarative Networks

no code implementations24 Jun 2023 Stephen Gould, Ming Xu, Zhiwei Xu, Yanbin Liu

We explore conditions for when the gradient of a deep declarative node can be approximated by ignoring constraint terms and still result in a descent direction for the global loss function.

Stackelberg Decision Transformer for Asynchronous Action Coordination in Multi-Agent Systems

no code implementations13 May 2023 Bin Zhang, Hangyu Mao, Lijuan Li, Zhiwei Xu, Dapeng Li, Rui Zhao, Guoliang Fan

Our research contributes to the development of an effective and adaptable asynchronous action coordination method that can be widely applied to various task types and environmental configurations in MAS.

Decision Making Multi-agent Reinforcement Learning

From Explicit Communication to Tacit Cooperation:A Novel Paradigm for Cooperative MARL

no code implementations28 Apr 2023 Dapeng Li, Zhiwei Xu, Bin Zhang, Guoliang Fan

Centralized training with decentralized execution (CTDE) is a widely-used learning paradigm that has achieved significant success in complex tasks.

SEA: A Spatially Explicit Architecture for Multi-Agent Reinforcement Learning

no code implementations25 Apr 2023 Dapeng Li, Zhiwei Xu, Bin Zhang, Guoliang Fan

In addition, our structure can be applied to various existing mainstream reinforcement learning algorithms with minor modifications and can deal with the problem with a variable number of agents.

Multi-agent Reinforcement Learning reinforcement-learning

Inducing Stackelberg Equilibrium through Spatio-Temporal Sequential Decision-Making in Multi-Agent Reinforcement Learning

no code implementations20 Apr 2023 Bin Zhang, Lijuan Li, Zhiwei Xu, Dapeng Li, Guoliang Fan

In multi-agent reinforcement learning (MARL), self-interested agents attempt to establish equilibrium and achieve coordination depending on game structure.

Decision Making Multi-agent Reinforcement Learning

Style Miner: Find Significant and Stable Explanatory Factors in Time Series with Constrained Reinforcement Learning

no code implementations21 Mar 2023 Dapeng Li, Feiyang Pan, Jia He, Zhiwei Xu, Dandan Tu, Guoliang Fan

In high-dimensional time-series analysis, it is essential to have a set of key factors (namely, the style factors) that explain the change of the observed variable.

Time Series Time Series Analysis

Adversarial Purification with the Manifold Hypothesis

no code implementations26 Oct 2022 Zhaoyuan Yang, Zhiwei Xu, Jing Zhang, Richard Hartley, Peter Tu

In this work, we formulate a novel framework for adversarial robustness using the manifold hypothesis.

Adversarial Robustness Variational Inference

Clustering-Induced Generative Incomplete Image-Text Clustering (CIGIT-C)

no code implementations28 Sep 2022 Dongjin Guo, Xiaoming Su, Jiatai Wang, Limin Liu, Zhiyong Pei, Zhiwei Xu

2) For missing data, the representations generated by existing methods are rarely guaranteed to suit clustering tasks.

Clustering Text Clustering +1

Enhanced Decentralized Federated Learning based on Consensus in Connected Vehicles

no code implementations22 Sep 2022 Xiaoyan Liu, Zehui Dong, Zhiwei Xu, Siyuan Liu, Jie Tian

Federated learning (FL) is emerging as a new paradigm to train machine learning (ML) models in distributed systems, including vehicles in V2X networks.

Decision Making Federated Learning

Consensus Learning for Cooperative Multi-Agent Reinforcement Learning

no code implementations6 Jun 2022 Zhiwei Xu, Bin Zhang, Dapeng Li, Zeren Zhang, Guangchong Zhou, Hao Chen, Guoliang Fan

Almost all multi-agent reinforcement learning algorithms without communication follow the principle of centralized training with decentralized execution.

Contrastive Learning Multi-agent Reinforcement Learning +2

Mingling Foresight with Imagination: Model-Based Cooperative Multi-Agent Reinforcement Learning

no code implementations20 Apr 2022 Zhiwei Xu, Dapeng Li, Bin Zhang, Yuan Zhan, Yunpeng Bai, Guoliang Fan

Recently, model-based agents have achieved better performance than model-free ones using the same computational budget and training time in single-agent environments.

Multi-agent Reinforcement Learning reinforcement-learning +1

Exploiting Problem Structure in Deep Declarative Networks: Two Case Studies

no code implementations24 Feb 2022 Stephen Gould, Dylan Campbell, Itzik Ben-Shabat, Chamin Hewa Koneputugodage, Zhiwei Xu

Deep declarative networks and other recent related works have shown how to differentiate the solution map of a (continuous) parametrized optimization problem, opening up the possibility of embedding mathematical optimization problems into end-to-end learnable models.

Vocal Bursts Valence Prediction

A Discrete-event-based Simulator for Distributed Deep Learning

no code implementations2 Dec 2021 Xiaoyan Liu, Zhiwei Xu, Yana Qin, Jie Tian

New intelligence applications are driving increasing interest in deploying deep neural networks (DNN) in a distributed way.

SIDE: State Inference for Partially Observable Cooperative Multi-Agent Reinforcement Learning

no code implementations13 May 2021 Zhiwei Xu, Yunpeng Bai, Dapeng Li, Bin Zhang, Guoliang Fan

As one of the solutions to the decentralized partially observable Markov decision process (Dec-POMDP) problems, the value decomposition method has achieved significant results recently.

Multi-agent Reinforcement Learning reinforcement-learning +3

RANP: Resource Aware Neuron Pruning at Initialization for 3D CNNs

1 code implementation9 Feb 2021 Zhiwei Xu, Thalaiyasingam Ajanthan, Vibhav Vineet, Richard Hartley

In this work, we introduce a Resource Aware Neuron Pruning (RANP) algorithm that prunes 3D CNNs at initialization to high sparsity levels.

3D Semantic Segmentation Stereo Matching +1

Newtonalized Orthogonal Matching Pursuit for Linear Frequency Modulated Pulse Frequency Agile Radar

no code implementations29 Jan 2021 Jiang Zhu, Honghui Guo, Ning Zhang, Chunyi Song, Zhiwei Xu

The linear frequency modulated (LFM) frequency agile radar (FAR) can synthesize a wide signal bandwidth through coherent processing while keeping the bandwidth of each pulse narrow.

Refining Semantic Segmentation with Superpixel by Transparent Initialization and Sparse Encoder

1 code implementation9 Oct 2020 Zhiwei Xu, Thalaiyasingam Ajanthan, Richard Hartley

We achieve it with fully-connected layers with Transparent Initialization (TI) and efficient logit consistency using a sparse encoder.

Segmentation Semantic Segmentation +1

RANP: Resource Aware Neuron Pruning at Initialization for 3D CNNs

1 code implementation6 Oct 2020 Zhiwei Xu, Thalaiyasingam Ajanthan, Vibhav Vineet, Richard Hartley

Specifically, the core idea is to obtain an importance score for each neuron based on their sensitivity to the loss function.

3D Semantic Segmentation Video Classification

Grid-less Variational Direction of Arrival Estimation in Heteroscedastic Noise Environment

no code implementations26 Dec 2019 Qi Zhang, Jiang Zhu, Yuantao Gu, Zhiwei Xu

This paper studies DOA in heteroscedastic noise (HN) environment, where the variance of noise is varied across the snapshots and the antennas.

Direction of Arrival Estimation

Fast and Differentiable Message Passing on Pairwise Markov Random Fields

1 code implementation24 Oct 2019 Zhiwei Xu, Thalaiyasingam Ajanthan, Richard Hartley

In addition to differentiability, the two main aspects that enable learning these model parameters are the forward and backward propagation time of the MRF optimization algorithm and its inference capabilities.

Denoising Semantic Segmentation

Semi-Supervised Self-Growing Generative Adversarial Networks for Image Recognition

no code implementations11 Aug 2019 Haoqian Wang, Zhiwei Xu, Jun Xu, Wangpeng An, Lei Zhang, Qionghai Dai

There are two main problems in label inference: how to measure the confidence of the unlabeled data and how to generalize the classifier.

Attribute Generative Adversarial Network

Gridless Multisnapshot Variational Line Spectral Estimation from Coarsely Quantized Samples

no code implementations20 Jun 2019 Ning Zhang, Jiang Zhu, Zhiwei Xu

Due to the increasing demand for low power and higher sampling rates, low resolution quantization for data acquisition has drawn great attention recently.

Quantization

One-bit LFMCW Radar: Spectrum Analysis and Target Detection

no code implementations23 May 2019 Benzhou Jin, Jiang Zhu, Qihui Wu, Yuhong Zhang, Zhiwei Xu

It is shown that compared to the conventional radar applying linear processing methods, one-bit LFMCW radar has about $1. 3$ dB performance gain when the input signal-to-noise ratios (SNRs) of targets are low.

Dimensionality Reduction Quantization

Vector Approximate Message Passing Algorithm for Structured Perturbed Sensing Matrix

no code implementations26 Aug 2018 Jiang Zhu, Qi Zhang, Xiangming Meng, Zhiwei Xu

In this paper, we consider a general form of noisy compressive sensing (CS) where the sensing matrix is not precisely known.

Signal Processing

Peeking the Impact of Points of Interests on Didi

no code implementations6 Apr 2018 Yonghong Tian, Zeyu Li, Zhiwei Xu, Xuying Meng, Bing Zheng

Recently, the online car-hailing service, Didi, has emerged as a leader in the sharing economy.

Variational Bayesian Line Spectral Estimation with Multiple Measurement Vectors

no code implementations17 Mar 2018 Jiang Zhu, Qi Zhang, Peter Gerstoft, Mihai-Alin Badiu, Zhiwei Xu

In this paper, the line spectral estimation (LSE) problem with multiple measurement vectors (MMVs) is studied utilizing the Bayesian methods.

Information Theory Information Theory

Towards Accurate Deceptive Opinion Spam Detection based on Word Order-preserving CNN

no code implementations25 Nov 2017 Siyuan Zhao, Zhiwei Xu, Limin Liu, Mengjie Guo

In order to effectively identify deceptive opinions, we need to comprehensively study the characteristics of deceptive opinions, and explore novel characteristics besides the textual semantics and emotional polarity that have been widely used in text analysis.

Spam detection text-classification +1

Founding Digital Currency on Imprecise Commodity

no code implementations29 Mar 2015 Zimu Yuan, Zhiwei Xu

Current digital currency schemes provide instantaneous exchange on precise commodity, in which "precise" means a buyer can possibly verify the function of the commodity without error.

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