Search Results for author: Hai Zhang

Found 18 papers, 2 papers with code

A Fourier Approach to the Parameter Estimation Problem for One-dimensional Gaussian Mixture Models

no code implementations19 Apr 2024 Xinyu Liu, Hai Zhang

Second, we reveal that there exists a fundamental limit to the problem of estimating the number of Gaussian components or model order in the mixture model if the number of i. i. d samples is finite.

Towards an Information Theoretic Framework of Context-Based Offline Meta-Reinforcement Learning

no code implementations4 Feb 2024 Lanqing Li, Hai Zhang, Xinyu Zhang, Shatong Zhu, Junqiao Zhao, Pheng-Ann Heng

As a marriage between offline RL and meta-RL, the advent of offline meta-reinforcement learning (OMRL) has shown great promise in enabling RL agents to multi-task and quickly adapt while acquiring knowledge safely.

Meta Reinforcement Learning Offline RL

Simple Semantic-Aided Few-Shot Learning

1 code implementation30 Nov 2023 Hai Zhang, Junzhe Xu, Shanlin Jiang, Zhenan He

This limitation severely constrains the potential of semantics in Few-Shot Learning.

Few-Shot Learning

SCAN-MUSIC: An Efficient Super-resolution Algorithm for Single Snapshot Wide-band Line Spectral Estimation

no code implementations27 Oct 2023 Zetao Fei, Hai Zhang

Moreover, in terms of speed, their performance is comparable to the state-of-the-art algorithms, while being more reliable for reconstructing line spectra with cluster structure.

Super-Resolution

IFF: A Super-resolution Algorithm for Multiple Measurements

no code implementations12 Mar 2023 Zetao Fei, Hai Zhang

The new feature also allows for a subsampling strategy that can circumvent the computation of singular-value decomposition for large matrices as in the usual subspace methods.

Super-Resolution

A measurement decoupling based fast algorithm for super-resolving point sources with multi-cluster structure

no code implementations1 Apr 2022 Ping Liu, Hai Zhang

We consider the problem of resolving closely spaced point sources in one dimension from their Fourier data in a bounded domain.

Global Guidance Network for Breast Lesion Segmentation in Ultrasound Images

no code implementations5 Apr 2021 Cheng Xue, Lei Zhu, Huazhu Fu, Xiaowei Hu, Xiaomeng Li, Hai Zhang, Pheng Ann Heng

The BD modules learn additional breast lesion boundary map to enhance the boundary quality of a segmentation result refinement.

Boundary Detection Image Segmentation +3

Mathematical Theory of Computational Resolution Limit in Multi-dimensions

no code implementations22 Mar 2021 Ping Liu, Hai Zhang

Our results indicate that there exists a phase transition phenomenon regarding to the super-resolution factor and the signal-to-noise ratio in each of the two recovery problems.

Super-Resolution

Differentially Private SGD with Non-Smooth Losses

no code implementations22 Jan 2021 Puyu Wang, Yunwen Lei, Yiming Ying, Hai Zhang

We significantly relax these restrictive assumptions and establish privacy and generalization (utility) guarantees for private SGD algorithms using output and gradient perturbations associated with non-smooth convex losses.

Mathematical theory for topological photonic materials in one dimension

no code implementations15 Jan 2021 Junshan Lin, Hai Zhang

The main focus is on the existence and stability of interface modes that are induced by topological properties of the bulk structure.

Band Gap Mathematical Physics Mathematical Physics

Randomized spectral co-clustering for large-scale directed networks

no code implementations25 Apr 2020 Xiao Guo, Yixuan Qiu, Hai Zhang, Xiangyu Chang

Directed networks are broadly used to represent asymmetric relationships among units.

Clustering

Randomized Spectral Clustering in Large-Scale Stochastic Block Models

no code implementations20 Jan 2020 Hai Zhang, Xiao Guo, Xiangyu Chang

In this paper, we study the spectral clustering using randomized sketching algorithms from a statistical perspective, where we typically assume the network data are generated from a stochastic block model that is not necessarily of full rank.

Clustering Community Detection +1

Cloud Removal with Fusion of High Resolution Optical and SAR Images Using Generative Adversarial Networks

no code implementations MDPI Remote Sensing 2020 Jianhao Gao, Qiangqiang Yuan, Jie Li, Hai Zhang, Xin Su

The approach can be roughly divided into two steps: in the first step, a specially designed convolutional neural network (CNN) translates the synthetic aperture radar (SAR) images into simulated optical images in an object-to-object manner; in the second step, the simulated optical image, together with the SAR image and the optical image corrupted by clouds, is fused to reconstruct the corrupted area by a generative adversarial network (GAN) with a particular loss function.

Cloud Removal Earth Observation +2

Differentially Private Precision Matrix Estimation

no code implementations6 Sep 2019 Wenqing Su, Xiao Guo, Hai Zhang

In this paper, we study the problem of precision matrix estimation when the dataset contains sensitive information.

Differential Privacy for Sparse Classification Learning

no code implementations2 Aug 2019 Puyu Wang, Hai Zhang

By the property of the post-processing holding of differential privacy, the proposed approach satisfies the $\epsilon-$differential privacy even when the original problem is unstable.

Classification General Classification +1

Retinal Vessels Segmentation Based on Dilated Multi-Scale Convolutional Neural Network

no code implementations11 Apr 2019 Yun Jiang, Ning Tan, Tingting Peng, Hai Zhang

In the proposed D-Net, the dilation convolution is used in the backbone network to obtain a larger receptive field without losing spatial resolution, so as to reduce the loss of feature information and to reduce the difficulty of tiny thin vessels segmentation.

Specificity

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