EDBT 2026 Demo / reviewers in the wild / expert
Chang Xu 0002
dblp:97/2966-2 · also Charles Xu 0002
· DBLP profile ↗
18ranked-venue papers in the field
2as first author
9since 2021 · last 2025
0000-0002-4756-0609ORCID · conflict
Domains — venue-derived; a paper can count in several
Data Mining & Knowledge Discovery · 15 (2 first)Other / Interdisciplinary · 2Database Systems & Data Management · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | FusionSAM: Visual Multi-Modal Learning with Segment Anything ModelabstractMultimodal image fusion and semantic segmentation are critical for autonomous driving. Despite advancements, current models often struggle with segmenting densely packed elements due to a lack of comprehensive fusion features for guidance during training. While the Segment Anything Model (SAM) allows precise control during fine-tuning through its flexible prompting encoder, its potential remains largely unexplored in the context of multimodal segmentation for natural images. In this paper, we introduce SAM into multimodal image segmentation for the first time, proposing a novel framework that combines Latent Space Token Generation (LSTG) and Fusion Mask Prompting (FMP) modules. This approach transforms the training methodology for multimodal segmentation from a traditional black-box approach to a controllable, prompt-based mechanism. Specifically, we obtain latent space features for both modalities through vector quantization and embed them into a cross-attention-based inter-domain fusion module to establish long-range dependencies between modalities. We then use these comprehensive fusion features as prompts to guide precise pixel-level segmentation. Extensive experiments on multiple public datasets demonstrate that our method significantly outperforms SAM and SAM2 in multimodal autonomous driving scenarios, achieving an average improvement of 4.1% over the state-of-the-art method in segmentation mIoU, and the performance is also optimized in other multi-modal visual scenes. Daixun Li, Weiying Xie, Mingxiang Cao, Yunke Wang, Leyuan Fang, Yunsong Li 0001, Chang Xu 0002 |
KDD (2) | 8 |
| 2023 | DiffNAS: Bootstrapping Diffusion Models by Prompting for Better ArchitecturesabstractDiffusion models have recently exhibited remarkable performance on synthetic data. After a diffusion path is selected, a base model, such as UNet, operates as a denoising autoencoder, primarily predicting noises that need to be eliminated step by step. Consequently, it is crucial to employ a model that aligns with the expected budgets to facilitate superior synthetic performance. In this paper, we meticulously analyze the diffusion model and engineer a base model search approach, denoted "DiffNAS". Specifically, we leverage GPT-4 as a supernet to expedite the search, supplemented with a search memory to enhance the results. Moreover, we employ RFID as a proxy to promptly rank the experimental outcomes produced by GPT-4. We also adopt a rapid-convergence training strategy to boost search efficiency. Rigorous experimentation corroborates that our algorithm can augment the search efficiency by $2 \times$ under GPT-based scenarios, while also attaining a performance of 2.82 with 0.37 improvement in FID on CIFAR10 relative to the benchmark IDDPM algorithm. Xiu Su, Shan You, Fei Wang 0032, Chen Qian 0006, Chang Xu 0002 |
ICDM | 6 |
| 2023 | Learning to Schedule in Diffusion Probabilistic ModelsabstractRecently, the field of generative models has seen a significant advancement with the introduction of Diffusion Probabilistic Models (DPMs). The Denoising Diffusion Implicit Model (DDIM) was designed to reduce computational time by skipping a number of steps in the inference process of DPMs. However, the hand-crafted sampling schedule in DDIM, which relies on human expertise, has its limitations in considering all relevant factors in the sampling process. Additionally, the assumption that all instances should have the same schedule is not always valid. To address these problems, this paper proposes a method that leverages reinforcement learning to automatically search for an optimal sampling schedule for DPMs. This is achieved by a policy network that predicts the next step to visit based on the current state of the noisy image. The optimization of the policy network is accomplished using an episodic actor-critic framework, which incorporates reinforcement learning. Empirical results demonstrate the superiority of our approach over various datasets with different timesteps. We also observe that the trained sampling schedule has a strong generalization ability across different DPM baselines. Yunke Wang, AnhDung Dinh, Bo Du 0001, Chang Xu 0002 |
KDD | 5 |
| 2022 | Contrastive Code-Comment Pre-trainingabstractPre-trained models for Natural Languages (NL) have been recently shown to transfer well to Programming Languages (PL) and largely benefit different intelligence code-related tasks, such as code search, clone detection, programming translation and code document generation. However, existing pre-trained methods for programming languages are mainly conducted by masked language modeling and next sentence prediction at token or graph levels. This restricted form limits their performance and transferability since PL and NL have different syntax rules and the downstream tasks require a multimodal representation. Here we introduce C3P, a Contrastive Code-Comment Pre-training approach, to solve various downstream tasks by pre-training the multi-representation features on both programming and natural syntax. The model encodes the code syntax and natural language description (comment) by two encoders and the encoded embeddings are projected into a multi-modal space for learning the latent representation. In the latent space, C3P jointly trains the code and comment encoders by the symmetric loss function, which aims to maximize the cosine similarity of the correct code-comment pairs while minimizing the similarity of unrelated pairs. We verify the empirical performance of the proposed pre-trained models on multiple downstream code-related tasks. The comprehensive experiments demonstrate that C3P outperforms previous work on the understanding tasks of code search and code clone, as well as the generation tasks of programming translation and document generation. Furthermore, we validate the transferability of C3P to the new programming language which is not seen in the pre-training stage. The results show our model surpasses all supervised methods and in some programming language cases even outperforms prior pre-trained approaches. Code is available at https://github.com/TerryPei/C3P. Xiaohuan Pei, Daochang Liu, William Qian 0001, Chang Xu 0002 |
ICDM | 4 |
| 2022 | Self-Attention Gated Cognitive Diagnosis For Faster Adaptive Educational AssessmentsabstractCognitive diagnosis models map observations onto psychological internal traits, which have been widely used to construct personalized educational assessments. However, the challenges of the latent ability representation, accurate performance with explanatory and cold-start problems caused by limited handcraft skills still exist. In this paper, we introduce a selfadaptive Attention Gate Cognitive Diagnosis Model (AGCDM) based on a multi-layer hierarchical structure. Specifically, in the first two layers, our model embeds the item response logs into a higher expressive latent space, and the specific self-attention mechanism captures the rich information from the inner-dependencies correlation among the examinee, quiz and knowledge. In the next layer, the gate mechanism addresses the challenge of noisy information (slip and guess) over psychological reasons. We verify the empirical performance of our model on different educational tasks and all comparisons study conducted on the same training recipe. On the item response prediction task, the experiment results demonstrate our hierarchical model achieves state-of-the-art performance. Through the estimation of adaptive learning, we also validate the model’s effectiveness in addressing the limited skill problem in real scenarios. The learning tracks show that our model empowered by the meta-learning algorithm can be adaptive faster than the base model to the new different skill distribution set. Furthermore, we present the ablation study on the hierarchical architecture and detailed hyperparameters selections. The comparison results demonstrate the attention blocks yield the scores improvement, and the estimation of the noisy errors shows the gate mechanism boosts the detection accuracy on the slip and guess. Code is available at https://github.com/TerryPei/AGCDM. Xiaohuan Pei, Shuo Yang 0006, Chang Xu 0002 |
ICDM | 4 |
| 2022 | Sufficient Vision TransformerabstractCurrently, Vision Transformer (ViT) and its variants have demonstrated promising performance on various computer vision tasks. Nevertheless, task-irrelevant information such as background nuisance and noise in patch tokens would damage the performance of ViT-based models. In this paper, we develop Sufficient Vision Transformer (Suf-ViT) as a new solution to address this issue. In our research, we propose the Sufficiency-Blocks (S-Blocks) to be applied across the depth of Suf-ViT to disentangle and discard task-irrelevant information accurately. Besides, to boost the training of Suf-ViT, we formulate a Sufficient-Reduction Loss (SRLoss) leveraging the concept of Mutual Information (MI) that enables Suf-ViT to extract more reliable sufficient representations by removing task-irrelevant information. Extensive experiments on benchmark datasets such as ImageNet, ImageNet-C, and CIFAR-10 indicate that our method can achieve state-of-the-art or competing performance over other baseline methods. Codes are available at: https://github.com/zhicheng2T0/Sufficient-Vision-Transformer.git Zhi Cheng, Xiu Su, Xueyu Wang, Shan You, Chang Xu 0002 |
KDD | 5 |
| 2021 | Structure-Aware Stabilization of Adversarial Robustness with Massive Contrastive AdversariesabstractRecent researches indicate that the impact of adversarial perturbations on deep learning models is reflected not only on the alteration of predicted labels but also on the distortion of data structure in the representation space. Significant improvement of the model’s adversarial robustness can be achieved by reforming the structure-aware representation distortion. Current methods generally utilize the one-to-one representation alignment or the triplet information between the positive and negative pairs. However, in this paper, we show that the representation structure of the natural and adversarial examples cannot be well and stably captured if we only focus on a localized range of contrastive examples. To achieve better and more stable adversarial robustness, we propose to adjust the adversarial distortion of representation structure by using Massive Contrastive Adversaries (MCA). Inspired by the Noise-Contrastive Estimation (NCE), MCA exploits the contrastive information by employing m negative instances. Compared with existing methods, our method recruits a much wider range of negative examples per update, so a better and more stable representation relationship between the natural and adversarial examples can be captured. Theoretical analysis shows that the proposed MCA inherently maximizes a lower bound of the mutual information (MI) between the representations of the natural and adversarial examples. Empirical experiments on benchmark datasets demonstrate that MCA can achieve better and more stable intra-class compactness and inter-class divergence, which further induces better adversarial robustness. Shuo Yang 0006, Zeyu Feng, Bo Du 0001, Chang Xu 0002 |
ICDM | 5 |
| 2021 | PLP 2021: Workshop on Programming Language ProcessingabstractThe first international Workshop on Programming Language Processing presents interdisciplinary contributions that address programming language procession problems with machine learning and data mining techniques. Recently, there are lots of successful natural language processing methods. But the mining of programming languages could not exactly follow the manner of natural language processing. The difference between natural language and programming language brings in new research challenges and opportunities. The workshop will bring together researchers from machine learning, data mining and software engineering to discuss and debate the path forward for mining the value of programming languages. Chang Xu 0002, Siqi Ma 0001, David Lo 0001 |
KDD | 1 |
| 2021 | Workshop on Model MiningabstractHow to mine the knowledge in the pretrained models is of significance in achieving more promising performance, since practitioners have access to many pretrained models easily. This Workshop on Model Mining aims to investigate more diverse and advanced manners in mining knowledge within models, which tends to leverage the pretrained models more wisely, elegantly and systematically. There are many topics related to this workshop, such as distilling a lightweight model from a well-trained heavy model via teacher-student paradigm, and boosting the performance of the model by carefully designing the predecessor tasks, e.g., pre-training, self-supervised and contrastive learning. Model mining as a special way of data mining is relevant to SIGKDD, and its audience including researchers and engineers will benefit a lot for designing more advanced algorithms for their tasks. Shan You, Chang Xu 0002, Fei Wang 0032, Changshui Zhang |
KDD | 2 |
| 2020 | An innovative multi-label learning based algorithm for city data computing
Mengqing Mei, Yongjian Zhong, Fazhi He, Chang Xu 0002 |
GeoInformatica | 4 |
| 2020 | Joint hyperspectral unmixing for urban computing
Jihai Yang, Mingmei Jia, Chang Xu 0002, Shijun Li 0001 |
GeoInformatica | 3 |
| 2019 | Reinforced Molecule Generation with Heterogeneous StatesabstractDe novo molecular design and generation are frequently prescribed in the field of chemistry and biology, for it plays a critical role in maintaining the prosperity of the chemical industry and benefiting the drug discovery. In recent years, reinforcement learning-based methods leverage graphs to represent molecules and generate molecules as a decision making process. However, this vanilla graph representation may neglect the intrinsic context information with molecules and limits the generation performance accordingly. In this paper, we propose to augment the original graph states with the SMILES context vectors. As a result, SMILES representations are easily processed by a simple language model such that the general semantic features of a molecule can be extracted; and the graph representations perform better in handling the topology relationship of each atom. Moreover, we propose a framework that combines supervised learning and reinforcement learning algorithm to take a solid consideration of these two heterogeneous state representations of a molecule, which can fuse the information from both of them and extract more comprehensive features so that more sophisticated decisions can be made by the policy network. Our model also introduces two attention mechanisms, i.e., action-attention, and graph-attention, to further improve the performance. We conduct our experiments on a practical dataset, ZINC, and the experiment results demonstrate that our framework can outperform other baselines in the learning performance of molecule generation and chemical property optimization. Fangzhou Shi, Shan You, Chang Xu 0002 |
ICDM | 3 |
| 2019 | ROMIR: Robust Multi-View Image Re-RankingabstractIn multi-view re-ranking, multiple heterogeneous visual features are usually projected onto a low-dimensional subspace, and thus the resulting latent representation can be used for the subsequent similarity-based ranking. Albeit effective, this standard mechanism underplays the intrinsic structure underlying the latent subspace and does not take into account the substantial noise in the original spaces. In this paper, we propose a robust multi-view image re-ranking strategy. Due to the dramatic variability in image visual appearance, it is necessary to uncover the shared components underlying those query-related instances that are visually unlike for improving the re-ranking accuracy. Consequently, it is reasonable to assume the latent subspace enjoys the low-rank property and thus the subspace recovery can be achieved via the low-rank modeling accordingly. In addition, since the real-world data are usually partially contaminated, we employ `2;1-norm based sparsity constraint to appropriately model the sample-specific mapping noise for enhancing the model robustness. In order to produce discriminative representations, we encode a similarity preserving term in our multi-view embedding framework. As a result, the sample separability is maximally maintained in the latent subspace with sufficient discriminative power. The extensive evaluations on public landmark benchmarks demonstrate the efficacy and superiority of the proposed method. Jun Li 0033, Chang Xu 0002, Wankou Yang, Changyin Sun 0001, Kotagiri Ramamohanarao, Dacheng Tao |
IEEE Trans. Knowl. Data Eng. | 2 |
| 2018 | Online Dictionary Learning with ConfidenceabstractOnline dictionary learning has received intensive attention in signal processing field with streaming or dynamic data. Different from classical online dictionary learning methods that treat all atoms equally, in this paper, we present a novel online dictionary learning with a confidence parameter introduced on each of atoms. The confidence indicates the scale of the update of atoms during online learning; frequently estimated atoms are thus supposed to be updated less aggressively than those of low usage frequency. This updating mechanism is beneficial for learning with dirty examples. As a result, the outliers would be prevented from influencing much on the frequently used atoms that have been well estimated through the clean examples. In detail, we employ variance of the atoms to measure the confidence on the quality of the learned atoms. And frequently-used atoms are supposed to have smaller variances (i.e. more confidence) than those of low usage frequency. Our algorithm consists of two main parts, namely, confidence-weighted sparse coding and dictionary update with confidence fine-tuning, each of which can be solved efficiently by our designed optimization methods. In addition, due to the introduced confidence, our algorithm does not have to depend on the widely-used ℓ1norm in order to realize the robustness against the outliers, which is usually computationally expensive in the training cost. Experimental results on synthetic and benchmark datasets demonstrate the imposed confidence on atoms in the dictionary can improve the performance of the learned dictionary. The quality of the obtained dictionary is comparable to that of state-of-the-art robust online dictionary learning methods, however, our method is much faster than those ℓ1norm based ones. Shan You, Chang Xu 0002, Chao Xu 0006 |
ICDM | 2 |
| 2018 | Independent Feature and Label Components for Multi-label ClassificationabstractInvestigating correlation between example features and example labels is essential to solve classification problems. However, identification and calculation of the correlation between features and labels can be rather difficult for high-dimensional multi-label data. Both feature embedding and label embedding have been developed to tackle this challenge, and a shared subspace for both labels and features are usually learned by existing embedding methods to simultaneously reduce dimensionality of features and labels. In contrast, this paper suggests to learn separated subspaces for features and labels by maximizing the independence between components in each subspace and maximizing the correlation between these two subspaces. The learned independent label components indicates fundamental combinations of labels in multi-label datasets, which thus helps to reveals the correlation between labels. On the other hand, the learned independent feature components lead to a compact representation of example features. The connections between the proposed algorithm and existing embedding methods have been discussed. Experimental results on real-world multi-label datasets demonstrate the necessity of exploring independence components from multi-label data and the effectiveness of the proposed algorithm. Yongjian Zhong, Chang Xu 0002, Bo Du 0001, Lefei Zhang |
ICDM | 2 |
| 2018 | Towards Evolutionary CompressionabstractCompressing convolutional neural networks (CNNs) is essential for transferring the success of CNNs to a wide variety of applications to mobile devices. In contrast to directly recognizing subtle weights or filters as redundant in a given CNN, this paper presents an evolutionary method to automatically eliminate redundant convolution filters. We represent each compressed network as a binary individual of specific fitness. Then, the population is upgraded at each evolutionary iteration using genetic operations. As a result, an extremely compact CNN is generated using the fittest individual, which has the original network structure and can be directly deployed in any off-the-shelf deep learning libraries. In this approach, either large or small convolution filters can be redundant, and filters in the compressed network are more distinct. In addition, since the number of filters in each convolutional layer is reduced, the number of filter channels and the size of feature maps are also decreased, naturally improving both the compression and speed-up ratios. Experiments on benchmark deep CNN models suggest the superiority of the proposed algorithm over the state-of-the-art compression methods, e.g. combined with the parameter refining approach, we can reduce the storage requirement and the floating-point multiplications of ResNet-50 by a factor of 14.64x and 5.19x, respectively, without affecting its accuracy. Yunhe Wang 0001, Chang Xu 0002, Jiayan Qiu, Chao Xu 0006, Dacheng Tao |
KDD | 2 |
| 2017 | Learning from Multiple Teacher NetworksabstractTraining thin deep networks following the student-teacher learning paradigm has received intensive attention because of its excellent performance. However, to the best of our knowledge, most existing work mainly considers one single teacher network. In practice, a student may access multiple teachers, and multiple teacher networks together provide comprehensive guidance that is beneficial for training the student network. In this paper, we present a method to train a thin deep network by incorporating multiple teacher networks not only in output layer by averaging the softened outputs (dark knowledge) from different networks, but also in the intermediate layers by imposing a constraint about the dissimilarity among examples. We suggest that the relative dissimilarity between intermediate representations of different examples serves as a more flexible and appropriate guidance from teacher networks. Then triplets are utilized to encourage the consistence of these relative dissimilarity relationships between the student network and teacher networks. Moreover, we leverage a voting strategy to unify multiple relative dissimilarity information provided by multiple teacher networks, which realizes their incorporation in the intermediate layers. Extensive experimental results demonstrated that our method is capable of generating a well-performed student network, with the classification accuracy comparable or even superior to all teacher networks, yet having much fewer parameters and being much faster in running. Shan You, Chang Xu 0002, Chao Xu 0006, Dacheng Tao |
KDD | 2 |
| 2016 | Robust Extreme Multi-label LearningabstractTail labels in the multi-label learning problem undermine the low-rank assumption. Nevertheless, this problem has rarely been investigated. In addition to using the low-rank structure to depict label correlations, this paper explores and exploits an additional sparse component to handle tail labels behaving as outliers, in order to make the classical low-rank principle in multi-label learning valid. The divide-and-conquer optimization technique is employed to increase the scalability of the proposed algorithm while theoretically guaranteeing its performance. A theoretical analysis of the generalizability of the proposed algorithm suggests that it can be improved by the low-rank and sparse decomposition given tail labels. Experimental results on real-world data demonstrate the significance of investigating tail labels and the effectiveness of the proposed algorithm. Chang Xu 0002, Dacheng Tao, Chao Xu 0006 |
KDD | 1 |