GenAI4ELab/papercli-papers huggingface dataset:
JEN-1 DreamStyler: Customized Musical Concept Learning via Pivotal Parameters Tuning
Authors: Boyu Chen; Peike Li; Yao Yao; Alex Wang
Venue: AAAI 2025 (main)

Abstract: Large models for text-to-music generation have achieved significant progress, facilitating the creation of high-quality and varied musical compositions from provided text prompts. However, input text prompts may not precisely capture user requirements, particularly when the objective is to generate music that embodies a specific concept derived from a designated reference collection. In this paper, we propose a novel method for customized text-to-music generation, which can capture the concept from a two-minute reference music and generate a new piece of music conforming to the concept. We achieve this by fine-tuning a pretrained text-to-music model using the reference music. However, directly fine-tuning all parameters leads to overfitting issues. To address this problem, we propose a Pivotal Parameters Tuning method that enables the model to assimilate the new concept while preserving its original generative capabilities. Additionally, we identify a potential concept conflict when introducing multiple concepts into the pretrained model. We present a concept enhancement strategy to distinguish multiple concepts, enabling the fine-tuned model to generate music incorporating either individual or multiple concepts simultaneously. We also introduce a new dataset and evaluation protocol for this task. Our proposed JEN1-DreamStyler outperforms several baselines in both qualitative and quantitative evaluations.
Pseudo Informative Episode Construction for Few-Shot Class-Incremental Learning
Authors: Chaofan Chen; Xiaoshan Yang; Changsheng Xu
Venue: AAAI 2025 (main)

Abstract: Few-Shot Class-Incremental Learning (FSCIL) studies how to empower the machine learning system to learn novel classes with only a few annotated examples continually. To tackle the FSCIL task, recent state-of-the-art methods propose to employ the meta-learning mechanism, which constructs the pseudo incremental episodes/tasks in the training phase. However, these methods only select part of the base classes to construct the pseudo novel classes in the feature space of the base classes, which cannot mimic the real novel
classes of the testing scenario. To deal with this problem, we propose a new  Pseudo Informative Episode Construction (PIEC) framework. Specifically, we first perform distribution-level mixing to generate a set of pseudo novel classes in the feature space of the novel class. Then, we propose two diversity criteria to select the informative pseudo novel classes that have large discrepancies with each other and high information gain over the base classes to construct the pseudo incremental session. In this way, we can allow the model to learn rich new concepts beyond the base classes as in the real incremental session during the episodic training procedure, thus improving its generalization ability. Extensive experiments on three popular classification benchmarks (i.e., CUB200, miniImageNet, and CIFAR100) show that the proposed framework can outperform other state-of-the-art methods.
SemStereo: Semantic-Constrained Stereo Matching Network for Remote Sensing
Authors: Chen Chen; Liangjin Zhao; Yuanchun He; Yingxuan Long; Kaiqiang Chen; Zhirui Wang; Yanfeng Hu; Xian Sun
Venue: AAAI 2025 (main)

Abstract: Semantic segmentation and 3D reconstruction are two fundamental tasks in remote sensing, typically treated as separate or loosely coupled tasks. Despite attempts to integrate them into a unified network, the constraints between the two heterogeneous tasks are not explicitly modeled, since the pioneering studies either utilize a loosely coupled parallel structure or engage in only implicit interactions, failing to capture the inherent connections. In this work, we explore the connections between the two tasks and propose a new network that imposes semantic constraints on the stereo matching task, both implicitly and explicitly. Implicitly, we transform the traditional parallel structure to a new cascade structure termed Semantic-Guided Cascade structure, where the deep features enriched with semantic information are utilized for the computation of initial disparity maps, enhancing semantic guidance. Explicitly, we propose a Semantic Selective Refinement (SSR) module and a Left-Right Semantic Consistency (LRSC) module. The SSR refines the initial disparity map under the guidance of the semantic map. The LRSC ensures semantic consistency between two views via reducing the semantic divergence after transforming the semantic map from one view to the other using the disparity map. Experiments on the US3D and WHU datasets demonstrate that our method achieves state-of-the-art performance for both semantic segmentation and stereo matching.
Biased Incomplete Multi-View Learning
Authors: Haishun Chen; Cai Xu; Ziyu Guan; Wei Zhao; Jinlong Liu
Venue: AAAI 2025 (main)

Abstract: Considering the ubiquitous phenomenon of missing views in multi-view data, incomplete multi-view learning is a crucial task in many applications. Existing methods usually follow an impute-then-predict strategy for handling this problem. However, they often assume that the view-missing patterns are uniformly random in multi-view data, which does not agree with real-world scenarios. In practice, view-missing patterns often vary across different classes. For example, in the medical field, patients with rare diseases would take more examinations than those with common diseases; in the financial field, high-risk customers tend to receive evaluations from more views than ordinary ones. Hence, we often observe that data-rich classes suffer limited views while data-poor classes suffer limited samples. Previous methods would typically fail due to such biased view-missing patterns. This motivates us to delve into a new biased incomplete multi-view learning problem. To this end, we develop a Reliable Incomplete Multi-view Learning (RIML) method. RIML is a simple yet effective learning-free imputation framework that goes beyond the conventional approaches by considering information from all classes, rather than just relying on individual views or within-class samples. Specifically, we utilize an inter-class association matrix that allows data-poor classes to refer the knowledge from data-rich classes. This enables the construction of more reliable view-specific distributions, from which we perform multiple samplings to recover missing views. Additionally, to obtain a reliable multi-view representation for downstream tasks, we develop an enhanced focal loss with a category-aware marginal term to learn a more distinguishable feature space. Experiments on five multi-view datasets demonstrate that RIML significantly outperforms existing methods in both accuracy and robustness.
FedPop: Federated Population-based Hyperparameter Tuning
Authors: Haokun Chen; Denis Krompaß; Jindong Gu; Volker Tresp
Venue: AAAI 2025 (main)

Abstract: Federated Learning (FL) is a distributed machine learning (ML) paradigm, in which multiple clients collaboratively train ML models without centralizing their local data. Similar to conventional ML pipelines, the client local optimization and server aggregation procedure in FL are sensitive to the hyperparameter (HP) selection. Despite extensive research on tuning HPs for centralized ML, these methods yield suboptimal results when employed in FL. This is mainly because their "training-after-tuning" framework is unsuitable for FL with limited client computation power. While some approaches have been proposed for HP-Tuning in FL, they are limited to the HPs for client local updates. In this work, we propose a novel HP-tuning algorithm, called Federated Population-based Hyperparameter Tuning (FedPop), to address this vital yet challenging problem. FedPop employs population-based evolutionary algorithms to optimize the HPs, which accommodates various HP types at both the client and server sides. Compared with prior tuning methods, FedPop employs an online  "tuning-while-training" framework, offering computational efficiency and enabling the exploration of a broader HP search space. Our empirical validation on the common FL benchmarks and complex real-world FL datasets, including full-sized Non-IID ImageNet-1K, demonstrates the effectiveness of the proposed method, which substantially outperforms the concurrent state-of-the-art HP-tuning methods in FL.
Understanding Individual Agent Importance in Multi-Agent System via Counterfactual Reasoning
Authors: Jianming Chen; Yawen Wang; Junjie Wang; Xiaofei Xie; Jun Hu; Qing Wang; Fanjiang Xu
Venue: AAAI 2025 (main)

Abstract: Explaining multi-agent systems (MAS) is urgent as these systems become increasingly prevalent in various applications. Previous work has provided explanations for the actions or states of agents, yet falls short in understanding the blackboxed agent’s importance within a MAS and the overall team strategy. To bridge this gap, we propose EMAI, a novel agent-level explanation approach that evaluates the individual agent’s importance. Inspired by counterfactual reasoning, a larger change in reward caused by the randomized action of agent indicates its higher importance. We model it as a MARL problem to capture interactions across agents. Utilizing counterfactual reasoning, EMAI learns the masking agents to identify important agents. Specifically, we define the optimization function to minimize the reward difference before and after action randomization and introduce sparsity constraints to encourage the exploration of more action randomization of agents during training. The experimental results in seven multi-agent tasks demonstrate that EMAI achieves higher fidelity in explanations compared to baselines and provides more effective guidance in practical applications concerning understanding policies, launching attacks, and patching policies.
Cross-View Graph Consistency Learning for Invariant Graph Representations
Authors: Jie Chen; Hua Mao; Wai Lok Woo; Chuanbin Liu; Xi Peng
Venue: AAAI 2025 (main)

Abstract: Graph representation learning is fundamental for analyzing graph-structured data. Exploring invariant graph representations remains a challenge for most existing graph representation learning methods. In this paper, we propose a cross-view graph consistency learning (CGCL) method that learns invariant graph representations for link prediction. First, two complementary augmented views are derived from an incomplete graph structure through a coupled graph structure augmentation scheme. This augmentation scheme mitigates the potential information loss that is commonly associated with various data augmentation techniques involving raw graph data, such as edge perturbation, node removal, and attribute masking. Second, we propose a CGCL model that can learn invariant graph representations. A cross-view training scheme is proposed to train the proposed CGCL model. This scheme attempts to maximize the consistency information between one augmented view and the graph structure reconstructed from the other augmented view. Furthermore, we offer a comprehensive theoretical CGCL analysis. This paper empirically and experimentally demonstrates the effectiveness of the proposed CGCL method, achieving competitive results on graph datasets in comparisons with several state-of-the-art algorithms.
Error Analysis Affected by Heavy-Tailed Gradients for Non-Convex Pairwise Stochastic Gradient Descent
Authors: Jun Chen; Hong Chen; Bin Gu; Guodong Liu; Yingjie Wang; Weifu Li
Venue: AAAI 2025 (main)

Abstract: In recent years, there have been a growing number of works studying the generalization properties of stochastic gradient descent (SGD) from the perspective of algorithmic stability. However, few of them devote to simultaneously studying the generalization and optimization for the non-convex setting, especially pairwise SGD with heavy-tailed gradient noise. This paper considers the impact of the heavy-tailed gradient noise obeying sub-Weibull distribution on the stability-based learning guarantees for non-convex pairwise SGD by investigating its generalization and optimization jointly. Specifically, based on two novel pairwise uniform model stability tools, we firstly bound the generalization error of pairwise SGD in the general non-convex setting after bridging the quantitative relationships between stability and generalization error. Then, we further consider the practical heavy-tailed sub-Weibull gradient noise condition to establish a refined generalization bound without the bounded gradient condition. Finally, sharper error bounds for generalization and optimization are built by introducing the gradient dominance condition. Comparing these results reveals that sub-Weibull gradient noise brings some positive dependencies on the heavy-tailed strength for generalization and optimization. Furthermore, we extend our analysis to the corresponding pairwise minibatch SGD and derive the first stability-based near-optimal generalization and optimization bounds which are consistent with many empirical observations.
Semi-Supervised Multimodal Classification Through Learning from Modal and Strategic Complementarities
Authors: Junchi Chen; Richong Zhang; Junfan Chen
Venue: AAAI 2025 (main)

Abstract: Supervised multimodal classification has been proven to outperform unimodal classification in the image-text domain. However, this task is highly dependent on abundant labeled data. To perform multimodal classification in data-insufficient scenarios, in this study, we explore semi-supervised multimodal classification (SSMC) that only requires a small amount of labeled data and plenty of unlabeled data. Specifically, we first design baseline SSMC models by combining known semi supervised pseudo-labeling methods with the two most commonly used modal fusion strategies, i.e. feature-level fusion and label-level aggregation. Based on our investigation and empirical study of the baselines, we discover two complementarities that may benefit SSMC if properly exploited: the predictions from different modalities (modal complementarity) and modal fusion strategies for pseudo-labeling (strategic complementarity). Therefore, we propose a Modal and Strategic Complementarity (MSC) framework for SSMC. Concretely, to exploit modal complementarity, we propose to learn reliability weights for the predictions from different modalities and refine the fusion scores. To learn from strategic complementarity, we introduce a dual KL divergence loss to guide the balance of quantity and quality of pseudo-labeled data selection. Extensive empirical studies demonstrate the effectiveness of the proposed framework.
Integrating Sequence and Image Modeling in Irregular Medical Time Series Through Self-Supervised Learning
Authors: Liuqing Chen; Shuhong Xiao; Shixian Ding; Shanhai Hu; Lingyun Sun
Venue: AAAI 2025 (main)

Abstract: Medical time series are often irregular and face significant missingness, posing challenges for data analysis and clinical decision-making. Existing methods typically adopt a single modeling perspective, either treating series data as sequences or transforming them into image representations for further classification. In this paper, we propose a joint learning framework that incorporates both sequence and image representations. We also design three self-supervised learning strategies to facilitate the fusion of sequence and image representations, capturing a more generalizable joint representation. The results indicate that our approach outperforms seven other state-of-the-art models in three representative real-world clinical datasets. We further validate our approach by simulating two major types of real-world missingness through leave-sensors-out and leave-samples-out techniques. The results demonstrate that our approach is more robust and significantly surpasses other baselines in terms of classification performance.
Robust Logit Adjustment for Learning with Long-Tailed Noisy Data
Authors: MingCai Chen; Yuntao Du; Wenyu Jiang; Baoming Zhang; Shuai Feng; Yi Xin; Chongjun Wang
Venue: AAAI 2025 (main)

Abstract: Learning with noisy labels (LNL) methods have enabled the deployment of machine learning systems with imperfectly labeled data. However, these methods often struggle to identify noise in the presence of long-tailed (LT) class distributions, where the memorization effect becomes class-dependent. Conversely, LT methods are suboptimal under label noise, as it hinders access to accurate label frequency statistics. This study aims to address the long-tailed noisy data by bridging the methodological gap between LNL and LT approaches. We propose a direct solution, termed Robust Logit Adjustment, which estimates ground-truth labels through label refurbishment, thereby mitigating the impact of label noise. Simultaneously, our method incorporates the distribution of training-time corrected target labels into the LT method logit adjustment, providing class-rebalanced supervision. Extensive experiments on both synthetic and real-world long-tailed noisy datasets demonstrate the superior performance of our method.
Federated Foundation Models on Heterogeneous Time Series
Authors: Shengchao Chen; Guodong Long; Jing Jiang; Chengqi Zhang
Venue: AAAI 2025 (main)

Abstract: Training a general-purpose time series foundation models with robust generalization capabilities across diverse applications from scratch is still an open challenge. Efforts are primarily focused on fusing cross-domain time series datasets to extract shared subsequences as tokens for training models on Transformer architecture. However, due to significant statistical heterogeneity across domains, this cross-domain fusing approach doesn't work effectively as the same as fusing texts and images. To tackle this challenge, this paper proposes a novel federated learning approach to address the heterogeneity in time series foundation models training, namely FFTS. Specifically, each data-holding organization is treated as an independent client in a collaborative learning framework with federated settings, and then many client-specific local models will be trained to preserve the unique characteristics per dataset. Moreover, a new regularization mechanism will be applied to both client-side and server-side, thus to align the shared knowledge across heterogeneous datasets from different domains. Extensive experiments on benchmark datasets demonstrate the effectiveness of the proposed federated learning approach. The newly learned time series foundation models achieve superior generalization capabilities on cross-domain time series analysis tasks, including forecasting, imputation, and anomaly detection.
SpotDiff: Spatial Gene Expression Imputation Diffusion with Single-Cell RNA Sequencing Data Integration
Authors: Tianyi Chen; Yunfei Zhang; Lianxin Xie; Wenjun Shen; Si Wu; Hau-San Wong
Venue: AAAI 2025 (main)

Abstract: The advent of Spatial Transcriptomics (ST) has revolutionized understanding of tissue architecture by creating high-resolution maps of gene expression patterns. However, the low capture rate of ST leads to significant sparsity. The aim of imputation is to recover biological signals by imputing the dropouts in ST data to approximate the true expression values. In this paper, we introduce a Spatial Gene Expression Imputation Diffusion model to facilitate ST data imputation, and our model is referred to as SpotDiff. Specifically, we incorporate a spot-gene prompt learning module to capture the association between spots and genes. Further, SpotDiff integrates single-cell RNA sequencing data to impute gene expression at each spot. The proposed approach is able to reduce the uncertainty in the imputation process, since the aggregation of multiple single-cell measurements yield a stable representation of the corresponding spot expression profile. Extensive experiments have been performed to demonstrate that SpotDiff outperforms existing imputation methods across multiple benchmarks in terms of yielding more accurate and biologically relevant gene expression profiles, particularly in highly sparse scenarios.
Learnware Specification via Label-Aware Neural Embedding
Authors: Wei Chen; Jun-Xiang Mao; Min-Ling Zhang
Venue: AAAI 2025 (main)

Abstract: The learnware paradigm aims to establish a learnware dock system of numerous well-trained machine learning models, enabling users to reuse existing helpful models for their tasks instead of starting from scratch. Each learnware in the system is a well-established model submitted by its developer, associated with a specification generated by the learnware dock system. The specification characterizes the specialty of the corresponding model, enabling it to be identified accurately for new task requirements. Existing specification generation methods are mostly based on the Reduced Kernel Mean Embedding (RKME) technique, which uses the Maximum Mean Discrepancy (MMD) in the Reproducing Kernel Hilbert Space (RKHS) to seek a reduced set that characterizes the model's capabilities. However, existing RKME-based methods mainly utilize feature information to generate specifications by assuming the existence of the ground-truth labeling function, while leaving the label information, which is capable of providing rich semantic characterization, untouched. Furthermore, the quality of the generated specifications heavily relies on the choice of the kernels, which makes it prohibitive to adapt to all real-world scenarios. In this paper, to overcome the above limitations, we propose a novel specification approach named LANE, i.e., Label-Aware Neural Embedding. In LANE, the neural embedding space is utilized to replace the RKHS, effectively circumventing the step of kernel selection and thereby addressing the dependency on kernels in existing RKME-based specification methods. More importantly, LANE uses the label information as additional supervision to enhance the generation process, resulting in specifications of superior quality. Extensive experiments demonstrate the effectiveness and superiority of the proposed LANE approach in the learnware paradigm.
Make Domain Shift a Catastrophic Forgetting Alleviator in Class-Incremental Learning
Authors: Wei Chen; Yi Zhou
Venue: AAAI 2025 (main)

Abstract: In the realm of class-incremental learning (CIL), alleviating the catastrophic forgetting problem is a pivotal challenge. This paper discovers a counter-intuitive observation: by incorporating domain shift into CIL tasks, the forgetting rate is significantly reduced. Our comprehensive studies demonstrate that incorporating domain shift leads to a clearer separation in the feature distribution across tasks and helps reduce parameter interference during the learning process. Inspired by this observation, we propose a simple yet effective method named DisCo to deal with CIL tasks. DisCo introduces a lightweight prototype pool that utilizes contrastive learning to promote distinct feature distributions for the current task relative to previous ones, effectively mitigating interference across tasks. DisCo can be easily integrated into existing state-of-the-art class-incremental learning methods. Experimental results show that incorporating our method into various CIL methods achieves substantial performance improvements, validating the benefits of our approach in enhancing class-incremental learning by separating feature representation and reducing interference. These findings illustrate that DisCo can serve as a robust fashion for future research in class-incremental learning.