Jiajun Bu

Dr. Jiajun Bu


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2021 in IEEE Transactions on Medical Imaging
Verified
Journal Article
Closed access
DQDian Qin
Dian Qin
JBJiajun Bu
Jiajun Bu
ZLZhe Liu
Zhe Liu
XSXin Shen
Xin Shen
SZSheng Zhou
Sheng Zhou
HDHui-Fen Dai
Hui-Fen Dai
Recent advances have been made in applying convolutional neural networks to achieve more precise prediction results for medical image segmentation problems. However, the success of existing methods has highly relied on huge computational complexity and massive storage, which is impractical in the real-world scenario. To deal with this problem, we propose an efficient architecture by distilling knowledge from well-trained medical image segmentation networks to train another lightweight network. This architecture empowers the lightweight network to get a significant improvement on segmentation capability while retaining its runtime efficiency. We further devise a novel distillation module tailored for medical image segmentation to transfer semantic region information from teacher to student network. It forces the student network to mimic the extent of difference of representations calculated from different tissue regions. This module avoids the ambiguous boundary problem encountered when dealing with medical imaging but instead encodes the internal information of each semantic region for transferring. Benefited from our module, the lightweight network could receive an improvement of up to 32.6% in our experiment while maintaining its portability in the inference phase. The entire structure has been verified on two widely accepted public CT datasets LiTS17 and KiTS19. We demonstrate that a lightweight network distilled by our method has non-negligible value in the scenario which requires relatively high operating speed and low storage usage.

11 November 2024 in ACM Computing Surveys
Verified
Journal Article
Open access
SZSheng Zhou
Sheng Zhou
HXHONGJIA XU
HONGJIA XU
ZZZhuonan Zheng
Zhuonan Zheng
JCJiawei Chen
Jiawei Chen
ZLZhao Li
Zhao Li
MEMartin Ester
Martin Ester
Clustering is a fundamental machine learning task, which aim at assigning instances into groups so that similar samples belong to the same cluster while dissimilar samples belong to different clusters. Shallow clustering methods usually assume that data are collected and expressed as feature vectors within which clustering is performed. However, clustering high-dimensional data, such as images, texts, videos, and graphs, poses significant challenges for clustering tasks, such as indiscriminate representation and intricate relationships among instances. Over the past decades, deep learning has achieved remarkable success in effective representation learning and modeling complex relationships. Motivated by these advancements, Deep Clustering seeks to improve clustering outcomes through deep learning techniques, garnering considerable interest from both academia and industry. Despite many contributions to this vibrant area of research, the lack of systematic analysis and a comprehensive taxonomy has hindered progress in this field. In this survey, we first explore how deep learning can be integrated into deep clustering and identify two fundamental components: the representation learning module and the clustering module. Then, we summarize and analyze the representative design of these two modules. Furthermore, we introduce a novel taxonomy of deep clustering based on how these two modules interact, specifically through multistage, generative, iterative, and simultaneous approaches. In addition, we present well-known benchmark datasets, evaluation metrics, and open-source tools to clearly demonstrate different experimental approaches. Finally, we examine the practical applications of deep clustering and propose challenging areas for future research.

18 June 2021 in IEEE Transactions on Knowledge and Data Engineering
Verified
Journal Article
Closed access
ZZZhen Zhang
Zhen Zhang
JBJiajun Bu
Jiajun Bu
MEMartin Ester
Martin Ester
JZJianfeng Zhang
Jianfeng Zhang
ZLZhao Li
Zhao Li
CWCan Wang
Can Wang
Graph Neural Networks (GNNs), which generalize deep neural networks to graph-structured data, have drawn considerable attention and achieved state-of-the-art performance in numerous graph related tasks. However, existing GNN models mainly focus on designing graph convolution operations. The graph pooling (or downsampling) operations, that play an important role in learning hierarchical representations, are usually overlooked. In this paper, we proposed a novel multi-view graph pooling operator dubbed as MVPool, which ranks nodes across different views with different contextual graph information. Meanwhile, attention mechanism is utilized to promote the collaboration of different views for generating robust node rankings. Then the pooling operation adaptively selects a subset of nodes to form an induced subgraph based on the ranking list. To preserve the underlying graph topological information, we further introduce a structure learning mechanism to learn a refined graph structure for the pooled graph at each layer. The proposed MVPool operator is a general strategy that can be integrated into various graph neural network architectures. By combining MVPool operator with graph neural networks, we perform hierarchical representation learning for both node and graph level classification as well as clustering tasks. Experimental results on nine widely used benchmarks demonstrate the effectiveness of our proposed model.

4 December 2024 in Advanced Science
Verified
Journal Article
Open access
YGYang Gao
Yang Gao
XZXiang Zhang
Xiang Zhang
ZSZhongquan Sun
Zhongquan Sun
PCPayal Chandak
Payal Chandak
JBJiajun Bu
Jiajun Bu
HWHaishuai Wang
Haishuai Wang
Accurate prediction of Adverse Drug Reactions (ADRs) at the patient level is essential for ensuring patient safety and optimizing healthcare outcomes. Traditional machine learning‐based methods primarily focus on predicting potential ADRs for drugs, but they often fall short of capturing the complexity of individual demographics and the variations in ADRs experienced by different people. In this study, a novel framework called Precise Adverse Drug Reaction (PreciseADR) for patient‐level ADR prediction is proposed. The approach effectively integrates relations between patients and ADRs, and harnesses the power of heterogeneous Graph Neural Networks (GNNs) to address the limitations of traditional methods. Specifically, a heterogeneous graph representation of patients is constructed, encompassing nodes that represent patients, diseases, drugs, and ADRs. By leveraging edges in the graph, crucial connections are captured such as a patient being affected by diseases, taking specific drugs, and experiencing ADRs. Next, a GNN‐based model is utilized to learn latent representations of the patient nodes and facilitate the propagation of information throughout the graph structure. By employing patient embeddings that consider their diseases and drugs, potential ADRs can be accurately predicted. The PreciseADR is dedicated to effectively capturing both local and global dependencies within the heterogeneous graph, allowing for the identification of subtle patterns and interactions that play a significant role in ADRs. To evaluate the performance of the approach, extensive experiments are conducted on a large‐scale real‐world healthcare dataset with adverse reports from the FDA Adverse Event Reporting System (FAERS). Experimental results demonstrate that the PreciseADR achieves superior predictive performance in identifying patient‐level ADRs, surpassing the strongest baseline by 3.2% in AUC score and by 4.9% in Hit@10.

23 July 2022 in Neural Networks
Verified
Journal Article
Closed access
NMNing Ma
Ning Ma
JBJiajun Bu
Jiajun Bu
LLLixian Lu
Lixian Lu
JWJun Wen
Jun Wen
SZSheng Zhou
Sheng Zhou
XYXifeng Yan
Xifeng Yan

1 July 2006
Verified
Conference Paper
Closed access
MYMingyu You
Mingyu You
CCChun Chen
Chun Chen
JBJiajun Bu
Jiajun Bu
JLJia Liu
Jia Liu
TJTao Jianhua
Tao Jianhua
This paper presents an emotion recognition system from clean and noisy speech. Geodesic distance was adopted to preserve the intrinsic geometry of emotional speech. Based on the geodesic distance estimation, an enhanced Lipschitz embedding was developed to embed the 64-dimensional acoustic features into a six-dimensional space. In order to avoid the problems brought by noise reduction, emotion recognition from noisy speech was performed directly. Linear discriminant analysis (LDA), principal component analysis (PCA) and feature selection by sequential forward selection (SFS) with support vector machine (SVM) were also included to compress acoustic features before classifying the emotional states of clean and noisy speech. Experimental results demonstrate that compared with other methods, the proposed system makes approximately 10% improvement. The performance of our system is also robust when speech data is corrupted by increasing noise