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 Statistical Learning


BuildSTG: A Multi-building Energy Load Forecasting Method using Spatio-Temporal Graph Neural Network

arXiv.org Artificial Intelligence

Due to the extensive retention of building operation data, data-driven building load prediction methods have demonstrated powerful capabilities in forecasting building energy loads. Buildings with similar operating conditions, physical characteristics, and types often exhibit similar energy usage patterns, which are reflected in their operation data showing similar trends and spatial dependencies. However, conventional building load prediction methods have significant limitations in extracting these spatial dependencies. To address this challenge, this paper proposes a multi-building load prediction method based on spatio-temporal graph neural networks, which is divided into three main steps: graph representation, graph learning, and method interpretation. First, a graph representation method is developed that identifies building correlations based on intrinsic characteristics and environmental factors. Next, a multi-level spatiotemporal graph convolu-tional architecture with an attention mechanism is designed to predict energy loads for multiple buildings. Finally, a model interpretation method based on the optimal graph structure obtained from the training process is devel-Corresponding author Email address: ychen@eitech.edu.cn Experiments on the Building Data Genome Project 2 dataset validate that the proposed method outperforms commonly used baseline models like XGBoost, SVR, FCNN, GRU, and Na ıve in terms of prediction accuracy. Additionally, the model demonstrates strong robustness and generalization, performing reliably under uncertainty and unseen data. Visualization of the building similarity matrix confirms the model's interpretability, revealing its ability to group similar buildings and establish meaningful spatial dependencies, proving that the proposed Att-GCN method for learning spatial dependencies between buildings with similar energy usage patterns is both reasonable and interpretable. Introduction With urbanization increasing, building energy consumption and carbon emissions are growing. Construction and operation of buildings account for 34% of global energy use, with 30% from operations.


Understanding Bias in Perceiving Dimensionality Reduction Projections

arXiv.org Artificial Intelligence

We assume a scenario where a practitioner wants to select DR techniques that produce projections suitable for analyzing their dataset. It is crucial to select projections with high faithfulness for reliable analysis, but practitioners tend to be more biased towards the visual interestingness. We verify the existence of such bias and investigate its underlying causes, providing a grounded basis for mitigating the biases. Selecting the dimensionality reduction technique that faithfully represents the structure is essential for reliable visual communication and analytics. In reality, however, practitioners favor projections for other attractions, such as aesthetics and visual saliency, over the projection's structural faithfulness, a bias we define as visual interestingness. In this research, we conduct a user study that (1) verifies the existence of such bias and (2) explains why the bias exists. Our study suggests that visual interestingness biases practitioners' preferences when selecting projections for analysis, and this bias intensifies with color-encoded labels and shorter exposure time. Based on our findings, we discuss strategies to mitigate bias in perceiving and interpreting DR projections.


MMGraphRAG: Bridging Vision and Language with Interpretable Multimodal Knowledge Graphs

arXiv.org Artificial Intelligence

Retrieval-Augmented Generation (RAG) enhances language model generation by retrieving relevant information from external knowledge bases. However, conventional RAG methods face the issue of missing multimodal information. Mul-timodal RAG methods address this by fusing images and text through mapping them into a shared embedding space, but they fail to capture the structure of knowledge and logical chains between modalities. Moreover, they also require large-scale training for specific tasks, resulting in limited generalizing ability. To address these limitations, we propose MMGraphRAG, which refines visual content through scene graphs and constructs a multimodal knowledge graph (MMKG) in conjunction with text-based KG. It employs spectral clustering to achieve cross-modal entity linking and retrieves context along reasoning paths to guide the generative process. Experimental results show that MMGraphRAG achieves state-of-the-art performance on the DocBench and MMLongBench datasets, demonstrating strong domain adaptability and clear reasoning paths.


Learning the Value Systems of Societies from Preferences

arXiv.org Artificial Intelligence

Aligning AI systems with human values and the value-based preferences of various stakeholders (their value systems) is key in ethical AI. In value-aware AI systems, decision-making draws upon explicit computational representations of individual values (groundings) and their aggregation into value systems. As these are notoriously difficult to elicit and calibrate manually, value learning approaches aim to automatically derive computational models of an agent's values and value system from demonstrations of human behaviour. Nonetheless, social science and humanities literature suggest that it is more adequate to conceive the value system of a society as a set of value systems of different groups, rather than as the simple aggregation of individual value systems. Accordingly, here we formalize the problem of learning the value systems of societies and propose a method to address it based on heuristic deep clustering. The method learns socially shared value groundings and a set of diverse value systems representing a given society by observing qualitative value-based preferences from a sample of agents. We evaluate the proposal in a use case with real data about travelling decisions.


Prostate Cancer Classification Using Multimodal Feature Fusion and Explainable AI

arXiv.org Artificial Intelligence

Prostate cancer, the second most prevalent male malignancy, requires advanced diagnostic tools. We propose an explainable AI system combining BERT (for textual clinical notes) and Random Forest (for numerical lab data) through a novel multimodal fusion strategy, achieving superior classification performance on PLCO-NIH dataset (98% accuracy, 99% AUC). While multimodal fusion is established, our work demonstrates that a simple yet interpretable BERT+RF pipeline delivers clinically significant improvements - particularly for intermediate cancer stages (Class 2/3 recall: 0.900 combined vs 0.824 numerical/0.725 textual). SHAP analysis provides transparent feature importance rankings, while ablation studies prove textual features' complementary value. This accessible approach offers hospitals a balance of high performance (F1=89%), computational efficiency, and clinical interpretability - addressing critical needs in prostate cancer diagnostics.


Exposing the Illusion of Fairness: Auditing Vulnerabilities to Distributional Manipulation Attacks

arXiv.org Artificial Intelligence

Proving the compliance of AI algorithms has become an important challenge with the growing deployment of such algorithms for real-life applications. Inspecting possible biased behaviors is mandatory to satisfy the constraints of the regulations of the EU Artificial Intelligence's Act. Regulation-driven audits increasingly rely on global fairness metrics, with Disparate Impact being the most widely used. Yet such global measures depend highly on the distribution of the sample on which the measures are computed. We investigate first how to manipulate data samples to artificially satisfy fairness criteria, creating minimally perturbed datasets that remain statistically indistinguishable from the original distribution while satisfying prescribed fairness constraints. Then we study how to detect such manipulation. Our analysis (i) introduces mathematically sound methods for modifying empirical distributions under fairness constraints using entropic or optimal transport projections, (ii) examines how an auditee could potentially circumvent fairness inspections, and (iii) offers recommendations to help auditors detect such data manipulations. These results are validated through experiments on classical tabular datasets in bias detection.


Novel Pivoted Cholesky Decompositions for Efficient Gaussian Process Inference

arXiv.org Artificial Intelligence

The Cholesky decomposition is a fundamental tool for solving linear systems with symmetric and positive definite matrices which are ubiquitous in linear algebra, optimization, and machine learning. Its numerical stability can be improved by introducing a pivoting strategy that iteratively permutes the rows and columns of the matrix. The order of pivoting indices determines how accurately the intermediate decomposition can reconstruct the original matrix, thus is decisive for the algorithm's efficiency in the case of early termination. Standard implementations select the next pivot from the largest value on the diagonal. In the case of Bayesian nonparametric inference, this strategy corresponds to greedy entropy maximization, which is often used in active learning and design of experiments. We explore this connection in detail and deduce novel pivoting strategies for the Cholesky decomposition. The resulting algorithms are more efficient at reducing the uncertainty over a data set, can be updated to include information about observations, and additionally benefit from a tailored implementation. We benchmark the effectiveness of the new selection strategies on two tasks important to Gaussian processes: sparse regression and inference based on preconditioned iterative solvers. Our results show that the proposed selection strategies are either on par or, in most cases, outperform traditional baselines while requiring a negligible amount of additional computation.


Adaptive Fuzzy Time Series Forecasting via Partially Asymmetric Convolution and Sub-Sliding Window Fusion

arXiv.org Artificial Intelligence

At present, state-of-the-art forecasting models are short of the ability to capture spatio-temporal dependency and synthesize global information at the stage of learning. To address this issue, in this paper, through the adaptive fuzzified construction of temporal data, we propose a novel convolutional architecture with partially asymmetric design based on the scheme of sliding window to realize accurate time series forecasting. First, the construction strategy of traditional fuzzy time series is improved to further extract short and long term temporal interrelation, which enables every time node to automatically possess corresponding global information and inner relationships among them in a restricted sliding window and the process does not require human involvement. Second, a bilateral Atrous algorithm is devised to reduce calculation demand of the proposed model without sacrificing global characteristics of elements. And it also allows the model to avoid processing redundant information. Third, after the transformation of time series, a partially asymmetric convolutional architecture is designed to more flexibly mine data features by filters in different directions on feature maps, which gives the convolutional neural network (CNN) the ability to construct sub-windows within existing sliding windows to model at a more fine-grained level. And after obtaining the time series information at different levels, the multi-scale features from different sub-windows will be sent to the corresponding network layer for time series information fusion. Compared with other competitive modern models, the proposed method achieves state-of-the-art results on most of popular time series datasets, which is fully verified by the experimental results.


Before the Outrage: Challenges and Advances in Predicting Online Antisocial Behavior

arXiv.org Artificial Intelligence

Antisocial behavior (ASB) on social media-including hate speech, harassment, and trolling-poses growing challenges for platform safety and societal wellbeing. While prior work has primarily focused on detecting harmful content after it appears, predictive approaches aim to forecast future harmful behaviors-such as hate speech propagation, conversation derailment, or user recidivism-before they fully unfold. Despite increasing interest, the field remains fragmented, lacking a unified taxonomy or clear synthesis of existing methods. This paper presents a systematic review of over 49 studies on ASB prediction, offering a structured taxonomy of five core task types: early harm detection, harm emergence prediction, harm propagation prediction, behavioral risk prediction, and proactive moderation support. We analyze how these tasks differ by temporal framing, prediction granularity, and operational goals. In addition, we examine trends in modeling techniques-from classical machine learning to pre-trained language models-and assess the influence of dataset characteristics on task feasibility and generalization. Our review highlights methodological challenges, such as dataset scarcity, temporal drift, and limited benchmarks, while outlining emerging research directions including multilingual modeling, cross-platform generalization, and human-in-the-loop systems. By organizing the field around a coherent framework, this survey aims to guide future work toward more robust and socially responsible ASB prediction.


Comparing and Scaling fMRI Features for Brain-Behavior Prediction

arXiv.org Artificial Intelligence

Predicting behavioral variables from neuroimaging modalities such as magnetic resonance imaging (MRI) has the potential to allow the development of neuroimaging biomarkers of mental and neurological disorders. A crucial processing step to this aim is the extraction of suitable features. These can differ in how well they predict the target of interest, and how this prediction scales with sample size and scan time. Here, we compare nine feature subtypes extracted from resting-state functional MRI recordings for behavior prediction, ranging from regional measures of functional activity to functional connectivity (FC) and metrics derived with graph signal processing (GSP), a principled approach for the extraction of structure-informed functional features. We study 979 subjects from the Human Connectome Project Young Adult dataset, predicting summary scores for mental health, cognition, processing speed, and substance use, as well as age and sex. The scaling properties of the features are investigated for different combinations of sample size and scan time. FC comes out as the best feature for predicting cognition, age, and sex. Graph power spectral density is the second best for predicting cognition and age, while for sex, variability-based features show potential as well. When predicting sex, the low-pass graph filtered coupled FC slightly outperforms the simple FC variant. None of the other targets were predicted significantly. The scaling results point to higher performance reserves for the better-performing features. They also indicate that it is important to balance sample size and scan time when acquiring data for prediction studies. The results confirm FC as a robust feature for behavior prediction, but also show the potential of GSP and variability-based measures. We discuss the implications for future prediction studies in terms of strategies for acquisition and sample composition.