arXiv Machine Learning

GAUDI: Geometry-Aware Diffusion for Calibrated Air-Quality Time-Series Imputation

GAUDI is a geometry-aware diffusion model designed to impute missing blocks in air‑quality time‑series data. It aligns conditional diffusion with block‑specific geometry, preserving temporal and feature processing while conditioning on visible values, masks, variable identity, and diffusion steps, but omitting absolute time‑position embeddings. On the ItalyAir dataset with 50% block missingness, GAUDI achieves an RMSE of 0.340, outperforming full‑context and local CSDI baselines.

arXiv AI
Aug 26

Evaluating Deep Multivariate Imputation Models on Wearable Device Data

The paper introduces a new evaluation protocol for deep multivariate imputation models on wearable device data, addressing the issue of structured missingness where sensor features drop out together. Using a Garmin smartwatch dataset from an epilepsy patient, the authors generate realistic block-missing patterns from training data and show that matching the training protocol to this distribution reduces BRITS’ mean absolute error by 43%. They also extend BRITS with time‑of‑day encoding and compare it to linear interpolation and SAITS, finding that no single model dominates and that model rankings vary with evaluation design.

By Skye Goodman, Roussel Desmond Nzoyem, Leandro Junges, Peter Kissack, Yasser Qureshi, Amberly Brigden, Jeff Clark, Nawid Keshtmand
arXiv Machine Learning
Sep 11

RDDMPI: Residual Denoising Diffusion Model for Probabilistic Multivariate Time Series Imputation

RDDMPI introduces a residual denoising diffusion model for multivariate time series imputation. By decomposing the missing signal into a baseline reconstruction and a residual uncertainty component, the method conditions the diffusion process on both the completed signal and its latent representation, using a reliability-aware mechanism to balance baseline influence. Experiments on benchmark datasets show that this approach improves reconstruction accuracy and uncertainty quantification compared to prior diffusion-based methods.

By Ramiro Valdes Jara, David Chapman, Adam Meyers
arXiv Machine Learning
Oct 5

TSGuard: A Real-Time Framework for Detecting and Imputing Missing Data in Streaming Time Series

TSGuard is a real‑time framework that monitors, validates, and imputes missing values in streaming time series. It uses a lightweight graph‑aware temporal imputation model combined with constraint‑aware validation, fallback estimation, and operator‑facing explanations. The system integrates detection, imputation, and domain‑aware decision making—retaining or replacing values based on physical and spatial constraints—within a broader data‑quality loop, and offers interactive tools for operators to inspect and compare imputers in real time.

By Imane Hocine, Asma Abboura, Soror Sahri, Abhijith Senthilkumar, Yacine Hakimi, Gr\'egoire Danoy
arXiv AI
Aug 20

Discretizing Continuous Time Series for Imputation with Masked Diffusion Training

The paper introduces the Masked Diffusion Time-series Imputation Model (MDTIM), which uses a masked diffusion training paradigm to directly predict original values for time series imputation. It separates missing and observed data via a MASK token and employs Stochastic Discretization to convert continuous values into ordinal-aware tokens, preserving temporal dynamics. Experiments on multiple benchmarks show that MDTIM outperforms existing deterministic and generative baselines in robustness and scalability across various missing data scenarios.

By Dongbin Kim, Seungyun Lee, Geonwoo Shin, Jaewook Lee
arXiv Machine Learning
Oct 9

Low-Cost Sensor Calibration for Indoor Air Quality Monitoring: A Dataset, Evaluation Scenarios, and a Lightweight Model

The paper presents a six‑month dataset of indoor air‑quality measurements from low‑cost and reference sensors, collected at five locations with contextual metadata. It defines four evaluation scenarios—reference‑efficient, location‑transfer, long‑term drift, and event‑conditioned—to test spatial generalization and robustness to distribution shifts. A lightweight temporal model that compresses input windows and fuses residual temporal and feature information achieves strong calibration performance across all scenarios while keeping edge‑inference cost low.

By Jinyong Yun, Seokho Ahn, Hyungjin Kim, Sungbok Shin, Young-Duk Seo
arXiv AI
Jun 9

FADTI: Fourier and Attention Driven Diffusion for Multivariate Time Series Imputation

arXiv:2512. 15116v2 Announce Type: replace-cross Abstract: Multivariate time series imputation is fundamental in applications such as healthcare, traffic forecasting, and biological modeling, where sensor failures and irregular sampling lead to pervasive missing values.

By Runze Li, Hanchen Wang, Wenjie Zhang, Binghao Li, Yu Zhang, Xuemin Lin, Ying Zhang