pwc-archive/papers-with-abstracts huggingface dataset:
Revealing Covert Attention by Analyzing Human and Reinforcement Learning Agent Gameplay
Authors: Henrik Krauss, Takehisa Yairi
Date: 2025-04-15 00:00:00
Tasks: Reinforcement Learning (RL)

This study introduces a novel method for revealing human covert attention patterns using gameplay data alone, utilizing offline attention techniques from reinforcement learning (RL). We propose the contextualized, task-relevant (CTR) attention network, which generates attention maps from both human and RL agent gameplay in Atari environments. These maps are sparse yet retain the necessary information for the current player's decision making. We compare the CTR-derived attention maps with a temporally integrated overt attention (TIOA) model based on eye-tracking data, serving as a point of comparison and discussion. Visual inspection reveals distinct attention patterns: human CTR maps focus on the player and rather nearby opponents, occasionally shifting between stronger focus and broader views - sometimes even attending to empty space ahead. In contrast, agent maps maintain a consistent broad focus on most objects, including distant ones and the player. Quantitative analysis further demonstrates that human CTR maps align more closely with TIOA than agent maps do. Our findings indicate that the CTR attention network can effectively reveal human covert attention patterns from gameplay alone, without the need for additional data like brain activity recordings. This work contributes to understanding human-agent attention differences and enables the development of RL agents augmented with human covert attention.
Divergence of Empirical Neural Tangent Kernel in Classification Problems
Authors: Zixiong Yu, Songtao Tian, Guhan Chen
Date: 2025-04-15 00:00:00

This paper demonstrates that in classification problems, fully connected neural networks (FCNs) and residual neural networks (ResNets) cannot be approximated by kernel logistic regression based on the Neural Tangent Kernel (NTK) under overtraining (i.e., when training time approaches infinity). Specifically, when using the cross-entropy loss, regardless of how large the network width is (as long as it is finite), the empirical NTK diverges from the NTK on the training samples as training time increases. To establish this result, we first demonstrate the strictly positive definiteness of the NTKs for multi-layer FCNs and ResNets. Then, we prove that during training, % with the cross-entropy loss, the neural network parameters diverge if the smallest eigenvalue of the empirical NTK matrix (Gram matrix) with respect to training samples is bounded below by a positive constant. This behavior contrasts sharply with the lazy training regime commonly observed in regression problems. Consequently, using a proof by contradiction, we show that the empirical NTK does not uniformly converge to the NTK across all times on the training samples as the network width increases. We validate our theoretical results through experiments on both synthetic data and the MNIST classification task. This finding implies that NTK theory is not applicable in this context, with significant theoretical implications for understanding neural networks in classification problems.
Diversity-Driven Learning: Tackling Spurious Correlations and Data Heterogeneity in Federated Models
Authors: Gergely D. Németh, Eros Fanì, Yeat Jeng Ng, Barbara Caputo, Miguel Ángel Lozano, Nuria Oliver, Novi Quadrianto
Date: 2025-04-15 00:00:00
Tasks: Attribute, Diversity, Federated Learning, image-classification, Image Classification

Federated Learning (FL) enables decentralized training of machine learning models on distributed data while preserving privacy. However, in real-world FL settings, client data is often non-identically distributed and imbalanced, resulting in statistical data heterogeneity which impacts the generalization capabilities of the server's model across clients, slows convergence and reduces performance. In this paper, we address this challenge by first proposing a characterization of statistical data heterogeneity by means of 6 metrics of global and client attribute imbalance, class imbalance, and spurious correlations. Next, we create and share 7 computer vision datasets for binary and multiclass image classification tasks in Federated Learning that cover a broad range of statistical data heterogeneity and hence simulate real-world situations. Finally, we propose FedDiverse, a novel client selection algorithm in FL which is designed to manage and leverage data heterogeneity across clients by promoting collaboration between clients with complementary data distributions. Experiments on the seven proposed FL datasets demonstrate FedDiverse's effectiveness in enhancing the performance and robustness of a variety of FL methods while having low communication and computational overhead.
The Forward-Forward Algorithm: Characterizing Training Behavior
Authors: Reece Adamson
Date: 2025-04-15 00:00:00

The Forward-Forward algorithm is an alternative learning method which consists of two forward passes rather than a forward and backward pass employed by backpropagation. Forward-Forward networks employ layer local loss functions which are optimized based on the layer activation for each forward pass rather than a single global objective function. This work explores the dynamics of model and layer accuracy changes in Forward-Forward networks as training progresses in pursuit of a mechanistic understanding of their internal behavior. Treatments to various system characteristics are applied to investigate changes in layer and overall model accuracy as training progresses, how accuracy is impacted by layer depth, and how strongly individual layer accuracy is correlated with overall model accuracy. The empirical results presented suggest that layers deeper within Forward-Forward networks experience a delay in accuracy improvement relative to shallower layers and that shallower layer accuracy is strongly correlated with overall model accuracy.
A Rollout-Based Algorithm and Reward Function for Efficient Resource Allocation in Business Processes
Authors: Jeroen Middelhuis, Zaharah Bukhsh, Ivo Adan, Remco Dijkman
Date: 2025-04-15 00:00:00
Tasks: Deep Reinforcement Learning

Resource allocation plays a critical role in minimizing cycle time and improving the efficiency of business processes. Recently, Deep Reinforcement Learning (DRL) has emerged as a powerful tool to optimize resource allocation policies in business processes. In the DRL framework, an agent learns a policy through interaction with the environment, guided solely by reward signals that indicate the quality of its decisions. However, existing algorithms are not suitable for dynamic environments such as business processes. Furthermore, existing DRL-based methods rely on engineered reward functions that approximate the desired objective, but a misalignment between reward and objective can lead to undesired decisions or suboptimal policies. To address these issues, we propose a rollout-based DRL algorithm and a reward function to optimize the objective directly. Our algorithm iteratively improves the policy by evaluating execution trajectories following different actions. Our reward function directly decomposes the objective function of minimizing the mean cycle time. Maximizing our reward function guarantees that the objective function is minimized without requiring extensive reward engineering. The results show that our method consistently learns the optimal policy in all six evaluated business processes, outperforming the state-of-the-art algorithm that can only learn the optimal policy in two of the evaluated processes.
DeepSelective: Feature Gating and Representation Matching for Interpretable Clinical Prediction
Authors: Ruochi Zhang, Qian Yang, Xiaoyang Wang, Haoran Wu, Qiong Zhou, Yu Wang, Kewei Li, Yueying Wang, Yusi Fan, Jiale Zhang, Lan Huang, Chang Liu, Fengfeng Zhou
Date: 2025-04-15 00:00:00
Tasks: Data Compression, Decision Making, feature selection, Prognosis, Representation Learning

The rapid accumulation of Electronic Health Records (EHRs) has transformed healthcare by providing valuable data that enhance clinical predictions and diagnoses. While conventional machine learning models have proven effective, they often lack robust representation learning and depend heavily on expert-crafted features. Although deep learning offers powerful solutions, it is often criticized for its lack of interpretability. To address these challenges, we propose DeepSelective, a novel end to end deep learning framework for predicting patient prognosis using EHR data, with a strong emphasis on enhancing model interpretability. DeepSelective combines data compression techniques with an innovative feature selection approach, integrating custom-designed modules that work together to improve both accuracy and interpretability. Our experiments demonstrate that DeepSelective not only enhances predictive accuracy but also significantly improves interpretability, making it a valuable tool for clinical decision-making. The source code is freely available at http://www.healthinformaticslab.org/supp/resources.php .
Bipartite Ranking From Multiple Labels: On Loss Versus Label Aggregation
Authors: Michal Lukasik, Lin Chen, Harikrishna Narasimhan, Aditya Krishna Menon, Wittawat Jitkrittum, Felix X. Yu, Sashank J. Reddi, Gang Fu, Mohammadhossein Bateni, Sanjiv Kumar
Date: 2025-04-15 00:00:00

Bipartite ranking is a fundamental supervised learning problem, with the goal of learning a ranking over instances with maximal area under the ROC curve (AUC) against a single binary target label. However, one may often observe multiple binary target labels, e.g., from distinct human annotators. How can one synthesize such labels into a single coherent ranking? In this work, we formally analyze two approaches to this problem -- loss aggregation and label aggregation -- by characterizing their Bayes-optimal solutions. Based on this, we show that while both methods can yield Pareto-optimal solutions, loss aggregation can exhibit label dictatorship: one can inadvertently (and undesirably) favor one label over others. This suggests that label aggregation can be preferable to loss aggregation, which we empirically verify.
Subset-Contrastive Multi-Omics Network Embedding
Authors: Pedro Henrique da Costa Avelar, Min Wu, Sophia Tsoka
Date: 2025-04-15 00:00:00
Tasks: Contrastive Learning, Network Embedding

Motivation: Network-based analyses of omics data are widely used, and while many of these methods have been adapted to single-cell scenarios, they often remain memory- and space-intensive. As a result, they are better suited to batch data or smaller datasets. Furthermore, the application of network-based methods in multi-omics often relies on similarity-based networks, which lack structurally-discrete topologies. This limitation may reduce the effectiveness of graph-based methods that were initially designed for topologies with better defined structures. Results: We propose Subset-Contrastive multi-Omics Network Embedding (SCONE), a method that employs contrastive learning techniques on large datasets through a scalable subgraph contrastive approach. By exploiting the pairwise similarity basis of many network-based omics methods, we transformed this characteristic into a strength, developing an approach that aims to achieve scalable and effective analysis. Our method demonstrates synergistic omics integration for cell type clustering in single-cell data. Additionally, we evaluate its performance in a bulk multi-omics integration scenario, where SCONE performs comparable to the state-of-the-art despite utilising limited views of the original data. We anticipate that our findings will motivate further research into the use of subset contrastive methods for omics data.
Interpretable Hybrid-Rule Temporal Point Processes
Authors: Yunyang Cao, Juekai Lin, Hongye Wang, Wenhao Li, Bo Jin
Date: 2025-04-15 00:00:00
Tasks: Bayesian Optimization, Medical Diagnosis, Point Processes, valid

Temporal Point Processes (TPPs) are widely used for modeling event sequences in various medical domains, such as disease onset prediction, progression analysis, and clinical decision support. Although TPPs effectively capture temporal dynamics, their lack of interpretability remains a critical challenge. Recent advancements have introduced interpretable TPPs. However, these methods fail to incorporate numerical features, thereby limiting their ability to generate precise predictions. To address this issue, we propose Hybrid-Rule Temporal Point Processes (HRTPP), a novel framework that integrates temporal logic rules with numerical features, improving both interpretability and predictive accuracy in event modeling. HRTPP comprises three key components: basic intensity for intrinsic event likelihood, rule-based intensity for structured temporal dependencies, and numerical feature intensity for dynamic probability modulation. To effectively discover valid rules, we introduce a two-phase rule mining strategy with Bayesian optimization. To evaluate our method, we establish a multi-criteria assessment framework, incorporating rule validity, model fitting, and temporal predictive accuracy. Experimental results on real-world medical datasets demonstrate that HRTPP outperforms state-of-the-art interpretable TPPs in terms of predictive performance and clinical interpretability. In case studies, the rules extracted by HRTPP explain the disease progression, offering valuable contributions to medical diagnosis.
An Adaptive Dropout Approach for High-Dimensional Bayesian Optimization
Authors: Jundi Huang, Dawei Zhan
Date: 2025-04-15 00:00:00
Tasks: Bayesian Optimization

Bayesian optimization (BO) is a widely used algorithm for solving expensive black-box optimization problems. However, its performance decreases significantly on high-dimensional problems due to the inherent high-dimensionality of the acquisition function. In the proposed algorithm, we adaptively dropout the variables of the acquisition function along the iterations. By gradually reducing the dimension of the acquisition function, the proposed approach has less and less difficulty to optimize the acquisition function. Numerical experiments demonstrate that AdaDropout effectively tackle high-dimensional challenges and improve solution quality where standard Bayesian optimization methods often struggle. Moreover, it achieves superior results when compared with state-of-the-art high-dimensional Bayesian optimization approaches. This work provides a simple yet efficient solution for high-dimensional expensive optimization.
Accelerating Multiscale Modeling with Hybrid Solvers: Coupling FEM and Neural Operators with Domain Decomposition
Authors: Wei Wang, Maryam Hakimzadeh, Haihui Ruan, Somdatta Goswami
Date: 2025-04-15 00:00:00

Numerical solvers for PDEs face challenges in balancing computational cost and accuracy, particularly for multiscale and dynamical systems. Neural operators (NOs) can significantly speed up simulations; however, they face challenges such as error accumulation for dynamical systems and limited generalization in multiphysics problems. This work introduces a novel hybrid framework that integrates PI-NO with finite element method (FE) through domain decomposition and leverages numerical analysis for time marching. The core innovation lies in efficient coupling FE and NO subdomains via a Schwarz alternating method: regions with complex, nonlinear, or high-gradient behavior are resolved using a pretrained NO, while the remainder is handled by conventional FE. To address the challenges of dynamic systems, we embed a time-stepping scheme directly into the NO architecture, substantially reducing long-term error propagation. Also, an adaptive subdomain evolution strategy enables the ML resolved region to expand dynamically, capturing emerging fine scale features without remeshing. The framework efficacy has been validated across a range of problems, spanning static, quasi-static, and dynamic regimes (e.g., linear elasticity, hyperelasticity, and elastodynamics), demonstrating accelerated convergence (up to 20% improvement in convergence compared to conventional FE coupling) while preserving solution fidelity with error margins consistently below 1%. Our study shows that our hybrid solver: (1) maintains solution continuity across subdomain interfaces, (2) reduces computational costs by eliminating fine mesh requirements, (3) mitigates error accumulation in time dependent simulations, and (4) enables automatic adaptation to evolving physical phenomena. This work bridges the gap between numerical methods and AI-driven surrogates, offering a scalable pathway for high-fidelity multiscale simulations.
Trajectory Encoding Temporal Graph Networks
Authors: Jiafeng Xiong, Rizos Sakellariou
Date: 2025-04-15 00:00:00
Tasks: Graph Learning, Link Prediction, Node Classification

Temporal Graph Networks (TGNs) have demonstrated significant success in dynamic graph tasks such as link prediction and node classification. Both tasks comprise transductive settings, where the model predicts links among known nodes, and in inductive settings, where it generalises learned patterns to previously unseen nodes. Existing TGN designs face a dilemma under these dual scenarios. Anonymous TGNs, which rely solely on temporal and structural information, offer strong inductive generalisation but struggle to distinguish known nodes. In contrast, non-anonymous TGNs leverage node features to excel in transductive tasks yet fail to adapt to new nodes. To address this challenge, we propose Trajectory Encoding TGN (TETGN). Our approach introduces automatically expandable node identifiers (IDs) as learnable temporal positional features and performs message passing over these IDs to capture each node's historical context. By integrating this trajectory-aware module with a standard TGN using multi-head attention, TETGN effectively balances transductive accuracy with inductive generalisation. Experimental results on three real-world datasets show that TETGN significantly outperforms strong baselines on both link prediction and node classification tasks, demonstrating its ability to unify the advantages of anonymous and non-anonymous models for dynamic graph learning.
Measures of Variability for Risk-averse Policy Gradient
Authors: Yudong Luo, Yangchen Pan, Jiaqi Tan, Pascal Poupart
Date: 2025-04-15 00:00:00
Tasks: Decision Making, Decision Making Under Uncertainty

Risk-averse reinforcement learning (RARL) is critical for decision-making under uncertainty, which is especially valuable in high-stake applications. However, most existing works focus on risk measures, e.g., conditional value-at-risk (CVaR), while measures of variability remain underexplored. In this paper, we comprehensively study nine common measures of variability, namely Variance, Gini Deviation, Mean Deviation, Mean-Median Deviation, Standard Deviation, Inter-Quantile Range, CVaR Deviation, Semi_Variance, and Semi_Standard Deviation. Among them, four metrics have not been previously studied in RARL. We derive policy gradient formulas for these unstudied metrics, improve gradient estimation for Gini Deviation, analyze their gradient properties, and incorporate them with the REINFORCE and PPO frameworks to penalize the dispersion of returns. Our empirical study reveals that variance-based metrics lead to unstable policy updates. In contrast, CVaR Deviation and Gini Deviation show consistent performance across different randomness and evaluation domains, achieving high returns while effectively learning risk-averse policies. Mean Deviation and Semi_Standard Deviation are also competitive across different scenarios. This work provides a comprehensive overview of variability measures in RARL, offering practical insights for risk-aware decision-making and guiding future research on risk metrics and RARL algorithms.
Mamba-Based Ensemble learning for White Blood Cell Classification
Authors: Lewis Clifton, Xin Tian, Duangdao Palasuwan, Phandee Watanaboonyongcharoen, Ponlapat Rojnuckarin, Nantheera Anantrasirichai
Date: 2025-04-15 00:00:00
Tasks: Benchmarking, Classification, Ensemble Learning, Mamba

White blood cell (WBC) classification assists in assessing immune health and diagnosing various diseases, yet manual classification is labor-intensive and prone to inconsistencies. Recent advancements in deep learning have shown promise over traditional methods; however, challenges such as data imbalance and the computational demands of modern technologies, such as Transformer-based models which do not scale well with input size, limit their practical application. This paper introduces a novel framework that leverages Mamba models integrated with ensemble learning to improve WBC classification. Mamba models, known for their linear complexity, provide a scalable alternative to Transformer-based approaches, making them suitable for deployment in resource-constrained environments. Additionally, we introduce a new WBC dataset, Chula-WBC-8, for benchmarking. Our approach not only validates the effectiveness of Mamba models in this domain but also demonstrates their potential to significantly enhance classification efficiency without compromising accuracy. The source code can be found at https://github.com/LewisClifton/Mamba-WBC-Classification.
Roamify: Designing and Evaluating an LLM Based Google Chrome Extension for Personalised Itinerary Planning
Authors: Vikranth Udandarao, Noel Abraham Tiju, Muthuraj Vairamuthu, Harsh Mistry, Dhruv Kumar
Date: 2025-03-10 00:00:00
Tasks: Articles

In this paper, we present Roamify, an Artificial Intelligence powered travel assistant that aims to ease the process of travel planning. We have tested and used multiple Large Language Models like Llama and T5 to generate personalised itineraries per user preferences. Results from user surveys highlight the preference for AI powered mediums over existing methods to help in travel planning across all user age groups. These results firmly validate the potential need of such a travel assistant. We highlight the two primary design considerations for travel assistance: D1) incorporating a web-scraping method to gather up-to-date news articles about destinations from various blog sources, which significantly improves our itinerary suggestions, and D2) utilising user preferences to create customised travel experiences along with a recommendation system which changes the itinerary according to the user needs. Our findings suggest that Roamify has the potential to improve and simplify how users across multiple age groups plan their travel experiences.
Leveraging Auto-Distillation and Generative Self-Supervised Learning in Residual Graph Transformers for Enhanced Recommender Systems
Authors: Eya Mhedhbi, Youssef Mourchid, Alice Othmani
Date: 2025-04-08 00:00:00
Tasks: Graph Representation Learning, Recommendation Systems, Representation Learning, Self-Supervised Learning

This paper introduces a cutting-edge method for enhancing recommender systems through the integration of generative self-supervised learning (SSL) with a Residual Graph Transformer. Our approach emphasizes the importance of superior data enhancement through the use of pertinent pretext tasks, automated through rationale-aware SSL to distill clear ways of how users and items interact. The Residual Graph Transformer incorporates a topology-aware transformer for global context and employs residual connections to improve graph representation learning. Additionally, an auto-distillation process refines self-supervised signals to uncover consistent collaborative rationales. Experimental evaluations on multiple datasets demonstrate that our approach consistently outperforms baseline methods.