GenAI4ELab/papercli-papers huggingface dataset:
Scaling Diffusion Mamba with Bidirectional SSMs for Efficient 3D Shape Generation
Authors: Shentong Mo
Venue: AAAI 2025 (main)

Abstract: Recent advancements in sequence modeling have led to the development of the Mamba architecture, noted for its selective state space approach, offering a promising avenue for efficient long sequence handling. However, its application in 3D shape generation, particularly at high resolutions, remains underexplored. Traditional diffusion transformers (DiT) with self-attention mechanisms, despite their potential, face scalability challenges due to the cubic complexity of attention operations as input length increases. This complexity becomes a significant hurdle when dealing with high-resolution voxel sizes. To address this challenge, we introduce a novel diffusion architecture tailored for 3D point clouds generation—Diffusion Mamba (DiM-3D). This architecture forgoes traditional attention mechanisms, instead utilizing the inherent efficiency of the Mamba architecture to maintain linear complexity with respect to sequence length. DiM-3D is characterized by fast inference times and substantially lower computational demands, quantified in reduced Gflops, thereby addressing the key scalability issues of prior models. Our empirical results on the ShapeNet benchmark demonstrate that DiM-3D achieves state-of-the-art performance in generating high-fidelity and diverse 3D shapes. Additionally, DiM-3D shows superior capabilities in tasks like 3D point cloud completion. This not only proves the model's scalability but also underscores its efficiency in generating detailed, high-resolution voxels necessary for advanced 3D shape modeling, particularly excelling in environments requiring 256-resolution voxel sizes. Through these findings, we illustrate the exceptional scalability and efficiency of the Diffusion Mamba framework in 3D shape generation, setting a new standard for the field and paving the way for future explorations in high-resolution 3D modeling technologies.
The Dynamic Duo of Collaborative Masking and Target for Advanced Masked Autoencoder Learning
Authors: Shentong Mo
Venue: AAAI 2025 (main)

Abstract: Masked autoencoders (MAE) have recently succeeded in self-supervised vision representation learning. Previous work mainly applied custom-designed (e.g., random, block-wise) masking or teacher (e.g., CLIP)-guided masking and targets. However, they ignore the potential role of the self-training (student) model in giving feedback to the teacher for masking and targets. In this work, we present to integrate Collaborative Masking and Targets for boosting Masked AutoEncoders, namely CMT-MAE. Specifically, CMT-MAE leverages a simple collaborative masking mechanism through linear aggregation across attentions from both teacher and student models. We further propose using the output features from those two models as the collaborative target of the decoder. Our simple and effective framework pre-trained on ImageNet-1K achieves state-of-the-art linear probing and fine-tuning performance. In particular, using ViT-base, we improve the fine-tuning results of the vanilla MAE from 83.6% to 85.7%.
AutoSGNN: Automatic Propagation Mechanism Discovery for Spectral Graph Neural Networks
Authors: Shibing Mo; Kai Wu; Qixuan Gao; Xiangyi Teng; Jing Liu
Venue: AAAI 2025 (main)

Abstract: In real-world applications, spectral Graph Neural Networks (GNNs) are powerful tools for processing diverse types of graphs. However, a single GNN often struggles to handle different graph types—such as homogeneous and heterogeneous graphs—simultaneously. This challenge has led to the manual design of GNNs tailored to specific graph types, but these approaches are limited by the high cost of labor and the constraints of expert knowledge, which cannot keep up with the rapid growth of graph data. To overcome these challenges, we introduce AutoSGNN, an automated framework for discovering propagation mechanisms in spectral GNNs. AutoSGNN unifies the search space for spectral GNNs by integrating large language models with evolutionary strategies to automatically generate architectures that adapt to various graph types. Extensive experiments on nine widely-used datasets, encompassing both homophilic and heterophilic graphs, demonstrate that AutoSGNN outperforms state-of-the-art spectral GNNs and graph neural architecture search methods in both performance and efficiency.
Query-efficient Attack for Black-box Image Inpainting Forensics via Reinforcement Learning
Authors: Xianbo Mo; Shunquan Tan; Bin Li; Jiwu Huang
Venue: AAAI 2025 (main)

Abstract: Recently, image inpainting has become a common tool for manipulating nature images in a malicious manner, which has led to the rapid advancement of inpainting forensics. Although current forensics methods have shown precise location of inpainting regions and reliable robustness against image post-processing operations, it remains unclear whether they can effectively resist the possible attacks in real-world scenarios. To identify potential flaws, we propose a novel black-box anti-forensics framework to attack inpainting forensics methods, which employs reinforcement learning to generate a query-efficient countermeasure, named RLGC. To this end, we define reinforcement learning paradigm to model the Markov Decision Process of query-based black-box anti-forensics scenario. Specifically, pixel-wise agents are used to modulate anti-forensics images based on action selection and query forensics methods to obtain corresponding outputs. Later, reward function evaluates attack effect and image distortion with these outputs. To maximize the cumulative reward, policy and value networks are integrated and trained by Asynchronous Advantage Actor-Critic algorithm. Experimental results demonstrate that, without visually detectable distortion on anti-forensics images, RLGC achieves remarkable attack effects in a highly query-effcient way against various black-box inpainting forensics methods, even outperforming the most representative white-box attack method.
Unlocking the Game: Estimating Games in Möbius Representation for Explanation and High-Order Interaction Detection
Authors: Majid Mohammadi; Ilaria Tiddi; Annette Ten Teije
Venue: AAAI 2025 (main)

Abstract: Shapley value-based explanations are widely utilized to demystify predictions made by opaque models. Approaches to estimating Shapley values often approximate explanation games as inessential and estimate the Shapley value directly as feature attribution with a limited capacity to quantify feature interactions. This paper introduces a new approach for calculating Shapley values that relaxes the assumption of inessential games and is proven to provide additive feature attribution. The initial formulation of the proposed approach includes the estimation of game values in their Möbius representation with exponentially many parameters, but we put forward a polynomial-time algorithm designed to manage the game's numerous values and achieve an efficient linear-time computation of the Shapley value. Moreover, this formulation uniquely enables identifying only the significant high-order feature interactions amidst a potentially exponential set. Through experiments, we demonstrate the robust performance of our methodology in game estimation and in providing explanations for multiple black-box models.
Support Vector-based Estimation of Multilinear Games for Feature Selection and Explanation
Authors: Majid Mohammadi; Ilaria Tiddi; Annette Ten Teije
Venue: AAAI 2025 (main)

Abstract: In recent years, employing Shapley values to compute feature importance has gained considerable attention. Calculating these values inherently necessitates managing an exponential number of parameters—a challenge commonly mitigated through an additivity assumption coupled with linear regression. This paper proposes a novel approach by modeling supervised learning as a multilinear game, incorporating both direct and interaction effects to establish the requisite values for Shapley value computation. To efficiently handle the exponentially increasing parameters intrinsic to multilinear games, we introduce a support vector machine (SVM)-based method for parameter estimation, its complexity is predominantly contingent on the number of samples due to the implementation of a dual SVM formulation. Additionally, we unveil an optimized dynamic programming algorithm capable of directly computing the Shapley value and interaction index from the dual SVM. Our proposed methodology is versatile and we demonstrate that it can be applied to local explanation and feature selection. Experiments underscore the competitive efficacy of our proposed methods in terms of feature selection and explanation.
Continual Learning Using a Kernel-Based Method Over Foundation Models
Authors: Saleh Momeni; Sahisnu Mazumder; Bing Liu
Venue: AAAI 2025 (main)

Abstract: Continual learning (CL) learns a sequence of tasks incrementally. This paper studies the challenging CL setting of class-incremental learning (CIL). CIL has two key challenges: catastrophic forgetting (CF) and inter-task class separation (ICS). Despite numerous proposed methods, these issues remain persistent obstacles. This paper proposes a novel CIL method, called Kernel Linear Discriminant Analysis (KLDA), that can effectively avoid CF and ICS problems. It leverages only the powerful features learned in a foundation model (FM). However, directly using these features proves suboptimal. To address this, KLDA incorporates the Radial Basis Function (RBF) kernel and its Random Fourier Features (RFF) to enhance the feature representations from the FM, leading to improved performance. When a new task arrives, KLDA computes only the mean for each class in the task and updates a shared covariance matrix for all learned classes based on the kernelized features. Classification is performed using Linear Discriminant Analysis. Our empirical evaluation using text and image classification datasets demonstrates that KLDA significantly outperforms baselines. Remarkably, without relying on replay data, KLDA achieves accuracy comparable to joint training of all classes, which is considered the upper bound for CIL performance.
OmniCount: Multi-label Object Counting with Semantic-Geometric Priors
Authors: Anindya Mondal; Sauradip Nag; Xiatian Zhu; Anjan Dutta
Venue: AAAI 2025 (main)

Abstract: Object counting is pivotal for understanding the composition of scenes. Previously, this task was dominated by class-specific methods, which have gradually evolved into more adaptable class-agnostic strategies. However, these strategies come with their own set of limitations, such as the need for manual exemplar input and multiple passes for multiple categories, resulting in significant inefficiencies. This paper introduces a more practical approach enabling simultaneous counting of multiple object categories using an open-vocabulary framework. Our solution, OmniCount, stands out by using semantic and geometric insights (priors) from pre-trained models to count multiple categories of objects as specified by users, all without additional training. OmniCount distinguishes itself by generating precise object masks and leveraging varied interactive prompts via the Segment Anything Model for efficient counting. To evaluate OmniCount, we created the OmniCount-191 benchmark, a first-of-its-kind dataset with multi-label object counts, including points, bounding boxes, and VQA annotations. Our comprehensive evaluation in OmniCount-191, alongside other leading benchmarks, demonstrates OmniCount's exceptional performance, significantly outpacing existing solutions.
Adaptive Sampling to Reduce Epistemic Uncertainty Using Prediction Interval-Generation Neural Networks
Authors: Giorgio Morales; John W. Sheppard
Venue: AAAI 2025 (main)

Abstract: Obtaining high certainty in predictive models is crucial for making informed and trustworthy decisions in many scientific and engineering domains. 
However, extensive experimentation required for model accuracy can be both costly and time-consuming. 
This paper presents an adaptive sampling approach designed to reduce epistemic uncertainty in predictive models. 
Our primary contribution is the development of a metric that estimates potential epistemic uncertainty leveraging prediction interval-generation neural networks.
This estimation relies on the distance between the predicted upper and lower bounds and the observed data at the tested positions and their neighboring points. 
Our second contribution is the proposal of a batch sampling strategy based on Gaussian processes (GPs). 
A GP is used as a surrogate model of the networks trained at each iteration of the adaptive sampling process. 
Using this GP, we design an acquisition function that selects a combination of sampling locations to maximize the reduction of epistemic uncertainty across the domain.
We test our approach on three unidimensional synthetic problems and a multi-dimensional dataset based on an agricultural field for selecting experimental fertilizer rates.
The results demonstrate that our method consistently converges faster to minimum epistemic uncertainty levels compared to Normalizing Flows Ensembles, MC-Dropout, and simple GPs.
Rectified Lagrangian for Out-of-Distribution Detection in Modern Hopfield Networks
Authors: Ryo Moriai; Nakamasa Inoue; Masayuki Tanaka; Rei Kawakami; Satoshi Ikehata; Ikuro Sato
Venue: AAAI 2025 (main)

Abstract: Modern Hopfield networks (MHNs) have recently gained significant attention in the field of artificial intelligence because they can store and retrieve a large set of patterns with an exponentially large memory capacity. A MHN is generally a dynamical system defined with Lagrangians of memory and feature neurons,where memories associated with in-distribution (ID) samples are represented by attractors in the feature space. One major problem in existing MHNs lies in managing out-of-distribution (OOD) samples because it was originally assumed that all samples are ID samples. To address this, we propose the rectified Lagrangian (RegLag), a new Lagrangian for memory neurons that explicitly incorporates an attractor for OOD samples in the dynamical system of MHNs. RecLag creates a trivial point attractor for any interaction matrix, enabling OOD detection by identifying samples that fall into this attractor as OOD.  The interaction matrix is optimized so that the probability densities can be estimated to identify ID/OOD. We demonstrate the effectiveness of RecLag-based MHNs compared to energy-based OOD detection methods, including those using state-of-the-art Hopfield energies, across nine image datasets.
GLEN: Generalized Focal Loss Ensemble of Low-Rank Networks for Calibrated Visual Question Answering
Authors: Mahsa Mozaffari; Hitesh Sapkota; Qi Yu
Venue: AAAI 2025 (main)

Abstract: Deep learning models with large-scale backbones have been increasingly adopted to tackle complex visual question answering (VQA) problems in real settings. While providing powerful learning capacities to handle the high-dimensional and multimodal VQA data, these models tend to suffer from the memorization effect leading to overconfident predictions. This can significantly limit their applicability in critical domains (e.g., medicine, cyber-security, and public safety), where confidently wrong predictions may lead to severe consequences. In this work, we propose to perform novel low-rank network factorization, resulting in much better-calibrated networks. These low-rank factorized networks are then aggregated into an ensemble guided by a generalized focal loss to further improve the overall performance and calibration. The overall framework, referred to as the Generalized focal Loss Ensemble of low-rank Networks (GLEN), is an important step toward developing well-calibrated VQA models. We theoretically demonstrate that the generalized focal loss provides a more balanced bias-variance trade-off, which guarantees to lower the confidence of the incorrect predictions, resulting in improved calibration. Extensive experimentation conducted on benchmark datasets and comparison on various VQA models shows that GLEN leads to much better calibration over both in-distribution and out-of-distribution data without sacrificing the VQA accuracy.
MPTSNet: Integrating Multiscale Periodic Local Patterns and Global Dependencies for Multivariate Time Series Classification
Authors: Yang Mu; Muhammad Shahzad; Xiao Xiang Zhu
Venue: AAAI 2025 (main)

Abstract: Multivariate Time Series Classification (MTSC) is crucial in extensive practical applications, such as environmental monitoring, medical EEG analysis, and action recognition. Real-world time series datasets typically exhibit complex dynamics. To capture this complexity, RNN-based, CNN-based, Transformer-based, and hybrid models have been proposed. Unfortunately, current deep learning-based methods often neglect the simultaneous construction of local features and global dependencies at different time scales, lacking sufficient feature extraction capabilities to achieve satisfactory classification accuracy. To address these challenges, we propose a novel Multiscale Periodic Time Series Network (MPTSNet), which integrates multiscale local patterns and global correlations to fully exploit the inherent information in time series. Recognizing the multi-periodicity and complex variable correlations in time series, we use the Fourier transform to extract primary periods, enabling us to decompose data into multiscale periodic segments. Leveraging the inherent strengths of CNN and attention mechanism, we introduce the PeriodicBlock, which adaptively captures local patterns and global dependencies while offering enhanced interpretability through attention integration across different periodic scales. The experiments on UEA benchmark datasets demonstrate that the proposed MPTSNet outperforms 21 existing advanced baselines in the MTSC tasks.
WPMixer: Efficient Multi-Resolution Mixing for Long-Term Time Series Forecasting
Authors: Md Mahmuddun Nabi Murad; Mehmet Aktukmak; Yasin Yilmaz
Venue: AAAI 2025 (main)

Abstract: Time series forecasting is crucial for various applications, such as weather forecasting, power load forecasting, and financial analysis. In recent studies, MLP-mixer models for time series forecasting have been shown as a promising alternative to transformer-based models. However, the performance of these models is still yet to reach its potential. In this paper, we propose Wavelet Patch Mixer (WPMixer), a novel MLP-based model, for long-term time series forecasting, which leverages the benefits of patching, multi-resolution wavelet decomposition, and mixing. Our model is based on three key components: (i) multi-resolution wavelet decomposition, (ii) patching and embedding, and (iii) MLP mixing. Multi-resolution wavelet decomposition efficiently extracts information in both the frequency and time domains. Patching allows the model to capture an extended history with a look-back window and enhances capturing local information while MLP mixing incorporates global information. Our model significantly outperforms state-of-the-art MLP-based and transformer-based models for long-term time series forecasting in a computationally efficient way, demonstrating its efficacy and potential for practical applications.
Evaluating the Evaluator: Measuring LLMs’ Adherence to Task Evaluation Instructions
Authors: Bhuvanashree Murugadoss; Christian Poelitz; Ian Drosos; Vu Le; Nick McKenna; Carina Suzana Negreanu; Chris Parnin; Advait Sarkar
Venue: AAAI 2025 (main)

Abstract: LLMs-as-a-judge is a recently popularized method which replaces human judgements in task evaluation with automatic evaluation using LLMs. Due to widespread use of RLHF (Reinforcement Learning from Human Feedback), state-of-the-art LLMs like GPT4 and Llama3 are expected to have strong alignment with human preferences when prompted for a quality judgement, such as the coherence of a text. While this seems beneficial, it is not clear whether the assessments by an LLM-as-a-judge constitute only an evaluation based on the instructions in the prompts, or reflect its preference for high-quality data similar to its fine-tune data. 
To investigate how much influence prompting the LLMs-as-a-judge has on the alignment of AI judgements to human judgements, we analyze prompts with increasing levels of instructions about the target quality of an evaluation, for several LLMs-as-a-judge. Further, we compare to a prompt-free method using model perplexity as a quality measure instead. We aggregate a taxonomy of quality criteria commonly used across state-of-the-art evaluations with LLMs and provide this as a rigorous benchmark of models as judges.
Overall, we show that the LLMs-as-a-judge benefit only little from highly detailed instructions in prompts and that perplexity can sometimes align better with human judgements than prompting, especially on textual quality.
SLACE: A Monotone and Balance-Sensitive Loss Function for Ordinal Regression
Authors: Inbar Nachmani; Bar Genossar; Coral Scharf; Roee Shraga; Avigdor Gal
Venue: AAAI 2025 (main)

Abstract: Ordinal regression classifies an object to a class out of a given set of possible classes, where labels possess a natural order.  
It is relevant to a wide array of domains including risk assessment, sentiment analysis, image ranking, and recommender systems. Like common classification, 
the primary goal of ordinal regression is accuracy. 
Yet, in this context, the severity of prediction errors varies, e.g., in risk assessment, Critical Risk is more urgent than High risk and significantly more urgent than No risk. 
This leads to a modified objective of ensuring that the model's output is as close as possible to the correct class, considering the order of labels. Therefore, ordinal regression models should use ordinality-aware loss  
for training. In this work, we focus on two properties of ordinality-aware losses, namely monotonicity and balance sensitivity. We show that existing ordinal loss functions lack these properties and introduce SLACE (Soft Labels Accumulating Cross Entropy), a novel loss function that provably satisfies said properties. We demonstrate empirically that SLACE outperforms the state-of-the-art ordinal loss functions on most tabular ordinal regression benchmarks.
Constrained Generative Modeling with Manually Bridged Diffusion Models
Authors: Saeid Naderiparizi; Xiaoxuan Liang; Berend Zwartsenberg; Frank Wood
Venue: AAAI 2025 (main)

Abstract: In this paper we describe a novel framework for diffusion-based generative modeling on constrained spaces. In particular, we introduce manual bridges, a framework that expands the kinds of constraints that can be practically used to form so-called diffusion bridges. We develop a mechanism for combining multiple such constraints so that the resulting multiply-constrained model remains a manual bridge that respects all constraints. We also develop a mechanism for training a diffusion model that respects such multiple constraints while also adapting it to match a data distribution. We develop and extend theory demonstrating the mathematical validity of our mechanisms. Additionally, we demonstrate our mechanism in constrained generative modeling tasks, highlighting a particular high-value application in modeling trajectory initializations for path planning and control in autonomous vehicles.