Retrieval-augmented generation

Retrieval pipelines, vector search, chunking and reranking: how models are grounded in a corpus instead of their weights.

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arXiv Machine Learning
Sep 23

Can We Predict Anomaly Detection Performance from Embedding-Space Geometry?

The paper investigates whether the performance of anomaly detection systems can be predicted without labeled anomalies. For kNN-based detectors, it derives a lower bound on AUC that links detection performance to the separation and variance of inlier and outlier scores, and uses this to analyze how density variation, intrinsic dimensionality, and domain mismatch affect score variability. The authors introduce pseudo‑anomaly probes that provide a reference for estimating relative score separation, and demonstrate through experiments on DCASE benchmarks that these probes enable anomaly‑free model selection to outperform conventional development‑set selection, especially under domain shift.

By Kevin Wilkinghoff, Zheng-Hua Tan
arXiv Computer Vision
Sep 23

Vorch-Human: Unified Multi-Task Human-Centric Generation via Long-Horizon Continuation

Vorch-Human is a unified framework for human‑centric audio‑visual generation that handles multiple tasks—animating a person from speech, jointly generating speech and video from a voice reference, and synthesizing a scene from paired appearance and voice references—using a single dual‑stream audio‑video diffusion transformer. The model incorporates clean condition‑audio and condition‑video tokens, per‑token task embeddings, temporal position types, condition masks, and a shared multimodal prompt encoder to express diverse inputs such as driving speech, timbre examples, first frames, and subject images. A two‑level data pipeline supplies the necessary supervision by extracting speech, appearance, and timbre annotations from clips and linking consistent identity and outfit references across videos, while a frozen‑prefix recurrence enables long‑form audio‑driven generation with reduced boundary discontinuity and identity drift.

By Yang Ding, Haoran Yu, Xin Ma, Yulei Lu, Menglin Han, Yaole Wang, Siqian Yang, Gang Yue, Kaihao Zhang, Yaohui Wang, Lin Ma
Towards Data Science
Sep 22

Break Your Own RAG Pipeline Before Users Do

The article discusses a small adversarial test set designed to detect retrieval failures in Retrieval-Augmented Generation (RAG) pipelines that typical evaluation sets might miss. It emphasizes the importance of proactively testing your own RAG system to uncover hidden weaknesses before users encounter them. By using this targeted test set, developers can improve the reliability and robustness of their RAG models.

By Sara Nobrega
arXiv Computation and Language
Sep 22

Althea: The Fact-Checking--Metalearning Tradeoff in AI-Assisted Verification

Althea is a retrieval‑augmented system that supports user‑driven claim evaluation, matching standard pipelines on AVeriTeC while improving discrimination between supported and refuted claims. In a longitudinal survey experiment with 961 participants, two AI‑assisted treatments—Exploratory (guided reasoning) and Summary (synthesized verdicts)—initially boosted accuracy and confidence, but these gains faded after the system was removed, leaving no advantage over unrelated news. In contrast, a Self‑search baseline, which lacks a fading procedure, maintained a significant advantage, highlighting a fact‑checking–metalearning tradeoff where methods that improve immediate accuracy may not foster durable literacy gains.

By Svetlana Churina, Kokil Jaidka, Anab Maulana Barik, Harshit Aneja, Cai Yang, Insyirah Binte Imam Mujtahid, Wynne Hsu, Mong Li Lee
arXiv Computer Vision
Sep 22

Training-Free Spectral Transductive Refinement for Cross-Domain Few-Shot Classification

The paper introduces Spectral Transductive Refinement (STR), a training‑free method that refines class prototypes at test time using the geometry of a joint k‑nearest‑neighbour graph and a normalized‑Laplacian spectral coordinate system. STR operates solely on frozen visual embeddings, iteratively updating pseudo‑labelled queries to improve one‑shot and few‑shot classification under domain shift. Experiments on ResNet‑18 and ResNet‑10 backbones show STR outperforms single‑prototype baselines and rivals meta‑trained cross‑domain few‑shot methods, achieving the best 1‑shot average across eight target domains.

By Fahim Rahman, S. M. Tanjeeb Meheran Rohan, Md. Taimum Ibne Sayed, Asaduzzaman Herok, Md. Bakhtiar Hasan
arXiv Computer Vision
Sep 22

Resolution-Flexible Decoding for Hybrid Neural Video Representations

The paper introduces a resolution‑flexible decoder for hybrid neural video representations, using uniform 2× upsampling stages that adapt to any target resolution by tracing spatial sizes backward from the final output. After each stage, feature maps are aligned to the desired size via minimal padding or cropping, and the process is guided by intermediate reconstruction supervision and a difficulty‑aware frame sampling strategy. Experiments on the UVG dataset demonstrate that this framework improves reconstruction quality compared to existing NVR baselines.

By Taiga Hayami, Masaya Takabe, Hiroshi Watanabe
arXiv Machine Learning
Sep 22

Contrastive Siamese Representation Learning for Predictive Maintenance of Electrical Submersible Pumps

The paper introduces a fault‑diagnosis framework for electrical submersible pumps that uses Siamese contrastive representation learning to handle class imbalance and a prior‑corrected k‑nearest neighbor classifier for robust fault classification. It extracts discriminative vibration‑domain features, trains a Siamese network to cluster same‑fault samples, and applies a distance‑weighted KNN to mitigate imbalance. Validation with a Leave‑One‑ESP‑Out strategy shows consistent performance across unseen pump units, indicating potential for reliable predictive maintenance in offshore oil production.

By Seshu K. Damarla, Xiuli Zhu
arXiv Machine Learning
Sep 22

Causilo Technical Report

Causilo is a new tabular foundation model that delivers state‑of‑the‑art predictive performance while achieving exceptionally fast inference. On the TabArena benchmark it scores 1785.4 Elo with a median inference time of 0.10 seconds per 1 K test samples, outperforming TabPFN‑3.5‑Fast by 31.6% in speed and reaching the performance–efficiency Pareto frontier. The architecture builds on TabICL’s column‑then‑row design, adding a row‑refinement module that exchanges information among cell representations before a final column stage, and uses cross‑attention with a fixed number of summary tokens to keep attention cost linear in the number of features.

By Minyong Cho, Minho Jeong, Dooho Lee, Jinmo Lee, Jaemin Yoo