DAD4TS: Data-Augmentation-Oriented Diffusion Model for Time-Series Forecasting with Small-Scale Data
Pith reviewed 2026-05-20 12:18 UTC · model grok-4.3
The pith
A diffusion model jointly trained with a forecaster and steered by reinforcement learning generates synthetic samples that raise accuracy on small time-series datasets.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
DAD4TS trains a diffusion model to produce time-series augmentations by first mapping the scarce data into geometric space through mathematical projection rather than a VAE. A reinforcement learning agent then controls the generator so that only samples improving the joint forecasting objective are retained, while the forecaster and generator improve together in a single training loop.
What carries the argument
The reinforcement learning controller that selects diffusion-generated augmentations while the data generator and time-series forecaster are trained simultaneously.
If this is right
- Forecasting accuracy rises on real-world datasets that contain only a few hundred observations.
- The same joint-training recipe works across multiple forecasting architectures without architecture-specific changes.
- Generated samples improve both point forecasts and uncertainty estimates in the tested models.
- The method reduces the amount of real data needed to reach a target accuracy level.
Where Pith is reading between the lines
- The geometric-projection step could let diffusion models handle other sequential data types that lack large pretraining corpora.
- Extending the reinforcement learning reward to multi-step forecast horizons might further stabilize long-range predictions.
- The joint-training loop could be adapted to online settings where new observations arrive continuously.
Load-bearing premise
Mapping time-series data into geometric space with mathematical methods produces a diffusion model whose outputs are genuine improvements rather than noise that hurts forecasting.
What would settle it
Run the same forecasting models on the original small data versus the original data plus DAD4TS samples and check whether forecast error stays the same or increases on held-out test sets.
Figures
read the original abstract
Small-scale data is a critical problem in time-series forecasting tasks. Data augmentation is an effective strategy for this task, but it has a limitation in generating meaningful data. To address this limitation, we propose DAD4TS, a diffusion-model-based data augmentation method with reinforcement learning, designed for time-series forecasting with small-scale data. In DAD4TS, a data generator is simultaneously trained with a time-series model and controlled by a reinforcement learning model to efficiently generate samples that improve the forecast accuracy of the time-series model. To support small-scale data, we use mathematical methods instead of conventional VAE methods to train the diffusion model by projecting the time-series data into the geometric space. We validated the effectiveness of DAD4TS with seven comparative methods through qualitative and quantitative experiments on six real-world datasets and eight time-series models. As a result, DAD4TS was validated on five datasets.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript proposes DAD4TS, a diffusion-model-based data augmentation framework for time-series forecasting on small-scale data. A data generator is trained jointly with a forecasting model and steered by a reinforcement learning controller to produce augmentations that improve downstream accuracy. Time-series data are projected into geometric space via mathematical methods (rather than VAE) to enable diffusion training under limited samples. The approach is evaluated qualitatively and quantitatively against seven baselines on six real-world datasets using eight forecasting models, with reported effectiveness on five of the six datasets.
Significance. If the empirical results are substantiated, the work could provide a practical route to targeted data augmentation for small time-series datasets by coupling diffusion generation with RL-driven selection and a non-VAE geometric projection step. This combination addresses a common bottleneck in forecasting applications where data scarcity limits model performance.
major comments (1)
- [Abstract] Abstract: the claim of quantitative validation on six datasets with seven comparative methods and eight models is stated without any reported metrics, error bars, statistical significance tests, data-split details, or baseline implementations. Because the central claim rests on demonstrated improvement in forecast accuracy, the absence of these elements leaves the empirical support for the method unassessable from the provided description.
minor comments (2)
- Clarify the precise mathematical projection used to map time-series into geometric space and how it replaces VAE training; include a short derivation or pseudocode if the projection is novel.
- Provide the exact RL reward formulation and the joint training schedule (e.g., how often the generator, forecaster, and RL controller are updated) so that the simultaneous-training procedure can be reproduced.
Simulated Author's Rebuttal
We thank the referee for their detailed review and constructive comments on our manuscript. We address the major comment point by point below and will revise the paper accordingly to strengthen the presentation of our empirical results.
read point-by-point responses
-
Referee: [Abstract] Abstract: the claim of quantitative validation on six datasets with seven comparative methods and eight models is stated without any reported metrics, error bars, statistical significance tests, data-split details, or baseline implementations. Because the central claim rests on demonstrated improvement in forecast accuracy, the absence of these elements leaves the empirical support for the method unassessable from the provided description.
Authors: We acknowledge that the abstract, as currently written, provides a high-level summary without specific quantitative details. The full manuscript includes these elements in the Experiments section, including tables with metrics, error bars from multiple runs, details on data splits, baseline implementations, and statistical significance tests. To address this, we will revise the abstract to include a brief mention of key results, such as the average improvement in forecasting accuracy across the datasets where DAD4TS showed effectiveness, and note the use of statistical validation. This will make the central claim more assessable from the abstract alone. revision: yes
Circularity Check
No significant circularity in derivation chain
full rationale
The paper presents an empirical method for data augmentation in time-series forecasting using a diffusion model trained jointly with a forecaster and guided by reinforcement learning, with a geometric projection step substituted for VAE to handle small data. No load-bearing derivation, equation, or prediction is shown to reduce to its own inputs by construction. The central claims rest on the described training procedure and reported validation across six datasets and eight models rather than any self-referential fitting or self-citation chain that forces the result. The approach is self-contained as an engineering proposal with external experimental checks.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption Projecting time-series data into geometric space using mathematical methods enables effective diffusion model training for small-scale data without conventional VAE methods.
Lean theorems connected to this paper
-
IndisputableMonolith/Foundation/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
we use mathematical methods instead of conventional VAE methods to train the diffusion model by projecting the time-series data into the geometric space
-
IndisputableMonolith/Foundation/ArithmeticFromLogic.leanLogicNat.induction unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
The Selector is trained to evaluate the utility of each generated sample by using improvements in the forecasting performance ... as the reward signal
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
Works this paper leans on
-
[1]
Hengbo Liu, Ziqing Ma, Linxiao Yang, Tian Zhou, Rui Xia, Yi Wang, Qingsong Wen, and Liang Sun. Sadi: A self-adaptive decomposed interpretable framework for electric load forecasting under extreme events. InICASSP 2023 - 2023 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), pages 1–5, 2023. doi: 10.1109/ICASSP49357.2023.10096002
-
[2]
Diffusion convolutional recurrent neural network: Data-driven traffic forecasting
Yaguang Li, Rose Yu, Cyrus Shahabi, and Yan Liu. Diffusion convolutional recurrent neural network: Data-driven traffic forecasting. InInternational Conference on Learning Representations, 2018. URL https://openreview.net/forum?id=SJiHXGWAZ
work page 2018
-
[3]
Tripti Dimri, Shamshad Ahmad, and Mohammad Sharif. Time series analysis of climate variables using seasonal arima approach.Journal of Earth System Science, 129(1):149, 2020
work page 2020
-
[4]
Time series generation under data scarcity: A unified generative modeling approach
Tal Gonen, Itai Pemper, Ilan Naiman, Nimrod Berman, and Omri Azencot. Time series generation under data scarcity: A unified generative modeling approach. InThe Thirty-ninth Annual Conference on Neural Information Processing Systems, 2025. URLhttps://openreview.net/forum?id=p324ryBKTc
work page 2025
-
[5]
Deep time series models for scarce data
Qiyao Wang, Ahmed Farahat, Chetan Gupta, and Shuai Zheng. Deep time series models for scarce data. Neurocomputing, 456:504–518, 2021. ISSN 0925-2312. doi: https://doi.org/10.1016/j.neucom.2020.12.132. URLhttps://www.sciencedirect.com/science/article/pii/S0925231221001922
-
[6]
arXiv preprint arXiv:2002.12478 , year =
Qingsong Wen, Liang Sun, Fan Yang, Xiaomin Song, Jingkun Gao, Xue Wang, and Huan Xu. Time series data augmentation for deep learning: A survey.arXiv preprint arXiv:2002.12478, 2020
-
[7]
Nitesh V . Chawla, Kevin W. Bowyer, Lawrence O. Hall, and W. Philip Kegelmeyer. Smote: synthetic minority over-sampling technique.Journal of artificial intelligence research, 16:321–357, 2002
work page 2002
-
[8]
Masato Ishii and Atsushi Sato. Training deep neural networks with adversarially augmented features for small-scale training datasets. In2019 International Joint Conference on Neural Networks (IJCNN), pages 1–8, 2019. doi: 10.1109/IJCNN.2019.8852250
-
[9]
Curran Associates Inc., Red Hook, NY , USA, 2019
Jinsung Yoon, Daniel Jarrett, and Mihaela van der Schaar.Time-series generative adversarial networks. Curran Associates Inc., Red Hook, NY , USA, 2019
work page 2019
-
[10]
TimeV AE: A variational auto-encoder for multivariate time series generation, 2022
Abhyuday Desai, Cynthia Freeman, Zuhui Wang, and Ian Beaver. TimeV AE: A variational auto-encoder for multivariate time series generation, 2022. URLhttps://openreview.net/forum?id=VDdDvnwFoyM
work page 2022
-
[11]
Synthetic mobility feature generation for mental health prediction using diffusion models
Masahiro Suzuki, Megumi Kodaka, and Yusuke Fukazawa. Synthetic mobility feature generation for mental health prediction using diffusion models. In2024 IEEE/WIC International Conference on Web Intelligence and Intelligent Agent Technology (WI-IAT), pages 102–109, 2024. doi: 10.1109/WI-IAT62293.2024.00022
-
[12]
Diffusion-TS: Interpretable diffusion for general time series generation
Xinyu Yuan and Yan Qiao. Diffusion-TS: Interpretable diffusion for general time series generation. InThe Twelfth International Conference on Learning Representations, 2024. URL https://openreview.net/ forum?id=4h1apFjO99
work page 2024
-
[13]
Auggen: Synthetic augmentation using diffusion models can improve recognition
Parsa Rahimi, Damien Teney, and Sébastien Marcel. Auggen: Synthetic augmentation using diffusion models can improve recognition. InThe Thirty-ninth Annual Conference on Neural Information Processing Systems, 2025. URLhttps://openreview.net/forum?id=LuKlBH8DAT
work page 2025
-
[14]
Reaugment: Model zoo-guided rl for few-shot time series augmentation and forecasting, 2025
Haochen Yuan, Yutong Wang, Yihong Chen, Yunbo Wang, and Xiaokang Yang. Reaugment: Model zoo-guided rl for few-shot time series augmentation and forecasting, 2025. URL https://arxiv.org/ abs/2409.06282
-
[15]
Bowen Deng, Chang Xu, Hao Li, Yu-hao Huang, Min Hou, and Jiang Bian. Tardiff: Target-oriented diffusion guidance for synthetic electronic health record time series generation. InProceedings of the 31st ACM SIGKDD Conference on Knowledge Discovery and Data Mining V .2, KDD ’25, page 474–485, New York, NY , USA, 2025. Association for Computing Machinery. IS...
-
[16]
Junwei Deng, Chang Xu, Jiaqi W. Ma, and Jiang Bian. OATS: Online data augmentation for time series foundation models. InRecent Advances in Time Series Foundation Models Have We Reached the ’BERT Moment’?, 2025. URLhttps://openreview.net/forum?id=kxdRkZqJLp
work page 2025
-
[17]
Yang Yu, Ruizhe Ma, Wenbo Gu, and Zongmin Ma. Diffat: Effective data augmentation with diffusion models for time series forecasting.Engineering Applications of Artificial Intelligence, 161:112091,
-
[18]
doi: https://doi.org/10.1016/j.engappai.2025.112091
ISSN 0952-1976. doi: https://doi.org/10.1016/j.engappai.2025.112091. URL https://www. sciencedirect.com/science/article/pii/S0952197625020998. 10
-
[19]
Hongming Tan, Ting Chen, Ruochong Jin, and Wai Kin Victor Chan. Data augmentation in time series forecasting through inverted framework.Pattern Recognition Letters, 201:152–159, 2026. ISSN 0167-8655. doi: https://doi.org/10.1016/j.patrec.2026.01.019. URL https://www.sciencedirect.com/science/ article/pii/S0167865526000279
-
[20]
AutoDA-timeseries: Automated data augmentation for time series
Zijun Dou, Zhenhe Yao, Zhe Xie, Xidao Wen, Tong Xiao, and Dan Pei. AutoDA-timeseries: Automated data augmentation for time series. InThe Fourteenth International Conference on Learning Representations,
-
[21]
URLhttps://openreview.net/forum?id=vTLmHAkoIW
-
[22]
Chris Donahue, Julian McAuley, and Miller Puckette. Adversarial audio synthesis. InICLR, 2019
work page 2019
-
[23]
Tianlin Xu, Li Kevin Wenliang, Michael Munn, and Beatrice Acciaio. Cot-gan: Generating sequential data via causal optimal transport.Advances in neural information processing systems, 33:8798–8809, 2020
work page 2020
-
[24]
Kai Shu, Le Wu, Yuchang Zhao, Aiping Liu, Ruobing Qian, and Xun Chen. Data augmentation for seizure prediction with generative diffusion model.IEEE Transactions on Cognitive and Developmental Systems, 17(3):577–591, 2024
work page 2024
-
[25]
Yuren Zhang, Zhongnan Pu, and Lei Jing. A time-series data augmentation model through diffusion and transformer integration.arXiv preprint arXiv:2505.03790, 2025
-
[26]
Jonathan Ho, Ajay Jain, and Pieter Abbeel. Denoising diffusion probabilistic models.Advances in neural information processing systems, 33:6840–6851, 2020
work page 2020
-
[27]
Jinsung Yoon, Sercan O. Arik, and Tomas Pfister. Data valuation using reinforcement learning. In Proceedings of the 37th International Conference on Machine Learning, ICML’20. JMLR.org, 2020
work page 2020
-
[28]
What neural networks memorize and why: discovering the long tail via influence estimation
Vitaly Feldman and Chiyuan Zhang. What neural networks memorize and why: discovering the long tail via influence estimation. InProceedings of the 34th International Conference on Neural Information Processing Systems, NIPS ’20, Red Hook, NY , USA, 2020. Curran Associates Inc. ISBN 9781713829546
work page 2020
-
[29]
LA V A: Data valuation without pre-specified learning algorithms
Hoang Anh Just, Feiyang Kang, Tianhao Wang, Yi Zeng, Myeongseob Ko, Ming Jin, and Ruoxi Jia. LA V A: Data valuation without pre-specified learning algorithms. InThe Eleventh International Conference on Learning Representations, 2023. URLhttps://openreview.net/forum?id=JJuP86nBl4q
work page 2023
-
[30]
Kevin Jiang, Weixin Liang, James Y Zou, and Yongchan Kwon. Opendataval: a unified benchmark for data valuation.Advances in Neural Information Processing Systems, 36:28624–28647, 2023
work page 2023
-
[31]
Data readiness for ai: A 360-degree survey.ACM Comput
Kaveen Hiniduma, Suren Byna, and Jean Luca Bez. Data readiness for ai: A 360-degree survey.ACM Comput. Surv., 57(9), April 2025. ISSN 0360-0300. doi: 10.1145/3722214. URL https://doi.org/10. 1145/3722214
-
[32]
Auto-Encoding Variational Bayes
Diederik P Kingma and Max Welling. Auto-encoding variational bayes.arXiv preprint arXiv:1312.6114, 2013
work page internal anchor Pith review Pith/arXiv arXiv 2013
-
[33]
High-resolution image synthesis with latent diffusion models
Robin Rombach, Andreas Blattmann, Dominik Lorenz, Patrick Esser, and Björn Ommer. High-resolution image synthesis with latent diffusion models. InProceedings of the IEEE/CVF conference on computer vision and pattern recognition, pages 10684–10695, 2022
work page 2022
-
[34]
DOVE: Efficient one-step diffusion model for real-world video super-resolution
Zheng Chen, Zichen Zou, Kewei Zhang, Xiongfei Su, Xin Yuan, Yong Guo, and Yulun Zhang. DOVE: Efficient one-step diffusion model for real-world video super-resolution. InThe Thirty-ninth Annual Conference on Neural Information Processing Systems, 2025. URL https://openreview.net/forum? id=DkJImu7t3A
work page 2025
-
[35]
Principal components analysis (PCA) , journal =
Andrzej Ma ´ckiewicz and Waldemar Ratajczak. Principal components analysis (pca).Computers & Geosciences, 19(3):303–342, 1993. ISSN 0098-3004. doi: https://doi.org/10.1016/0098-3004(93)90090-R. URLhttps://www.sciencedirect.com/science/article/pii/009830049390090R
-
[36]
Abdul Fatir Ansari, Lorenzo Stella, Caner Turkmen, Xiyuan Zhang, Pedro Mercado, Huibin Shen, Olek- sandr Shchur, Syama Syndar Rangapuram, Sebastian Pineda Arango, Shubham Kapoor, Jasper Zschiegner, Danielle C. Maddix, Michael W. Mahoney, Kari Torkkola, Andrew Gordon Wilson, Michael Bohlke- Schneider, and Yuyang Wang. Chronos: Learning the language of time...
work page 2024
-
[37]
Tirex: Zero-shot forecasting across long and short horizons with enhanced in-context learning
Andreas Auer, Patrick Podest, Daniel Klotz, Sebastian Böck, Günter Klambauer, and Sepp Hochreiter. Tirex: Zero-shot forecasting across long and short horizons with enhanced in-context learning. In The Thirty-ninth Annual Conference on Neural Information Processing Systems, 2025. URL https: //openreview.net/forum?id=v7UqniC9pF. 11
work page 2025
-
[38]
Classifier-free diffusion guidance
Jonathan Ho and Tim Salimans. Classifier-free diffusion guidance. InNeurIPS 2021 Workshop on Deep Generative Models and Downstream Applications, 2021. URL https://openreview.net/forum?id= qw8AKxfYbI
work page 2021
-
[39]
DiffWave: A Versatile Diffusion Model for Audio Synthesis
Zhifeng Kong, Wei Ping, Jiaji Huang, Kexin Zhao, and Bryan Catanzaro. Diffwave: A versatile diffusion model for audio synthesis.arXiv preprint arXiv:2009.09761, 2020
work page internal anchor Pith review Pith/arXiv arXiv 2009
-
[40]
Flow straight and fast: Learning to generate and transfer data with rectified flow
Xingchao Liu, Chengyue Gong, and qiang liu. Flow straight and fast: Learning to generate and transfer data with rectified flow. InThe Eleventh International Conference on Learning Representations, 2023. URLhttps://openreview.net/forum?id=XVjTT1nw5z
work page 2023
-
[41]
Long short-term memory.Neural computation, 9(8):1735–1780, 1997
Sepp Hochreiter and Jürgen Schmidhuber. Long short-term memory.Neural computation, 9(8):1735–1780, 1997
work page 1997
-
[42]
Attention is all you need.Advances in neural information processing systems, 30, 2017
Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N Gomez, Łukasz Kaiser, and Illia Polosukhin. Attention is all you need.Advances in neural information processing systems, 30, 2017
work page 2017
-
[43]
iTransformer: Inverted Transformers Are Effective for Time Series Forecasting
Yong Liu, Tengge Hu, Haoran Zhang, Haixu Wu, Shiyu Wang, Lintao Ma, and Mingsheng Long. itrans- former: Inverted transformers are effective for time series forecasting.arXiv preprint arXiv:2310.06625, 2023
work page internal anchor Pith review Pith/arXiv arXiv 2023
-
[44]
A Time Series is Worth 64 Words: Long-term Forecasting with Transformers
Yuqi Nie, Nam H Nguyen, Phanwadee Sinthong, and Jayant Kalagnanam. A time series is worth 64 words: Long-term forecasting with transformers.arXiv preprint arXiv:2211.14730, 2022
work page internal anchor Pith review Pith/arXiv arXiv 2022
-
[45]
TimesNet: Temporal 2D-Variation Modeling for General Time Series Analysis
Haixu Wu, Tengge Hu, Yong Liu, Hang Zhou, Jianmin Wang, and Mingsheng Long. Timesnet: Temporal 2d-variation modeling for general time series analysis.arXiv preprint arXiv:2210.02186, 2022
work page internal anchor Pith review Pith/arXiv arXiv 2022
-
[46]
InForty-first International Conference on Machine Learning, 2024
Zijie Pan, Yushan Jiang, Sahil Garg, Anderson Schneider, Yuriy Nevmyvaka, and Dongjin Song.S2IP- LLM: Semantic space informed prompt learning with llm for time series forecasting. InForty-first International Conference on Machine Learning, 2024
work page 2024
-
[47]
OLinear: A linear model for time series forecasting in orthogonally transformed domain
Wenzhen Yue, Yong Liu, Hao Wang, Haoxuan Li, Xianghua Ying, Ruohao Guo, Bowei Xing, and Ji Shi. OLinear: A linear model for time series forecasting in orthogonally transformed domain. In The Thirty-ninth Annual Conference on Neural Information Processing Systems, 2025. URL https: //openreview.net/forum?id=DAyKP1tvwI
work page 2025
-
[48]
Tempusbench: An evaluation framework for time-series forecasting
Denizalp Goktas, Amy Greenwald, Gerardo Riano-Briceno, Alexandra Magnusson, Alif Abdullah, and Beatriz de Lucio. Tempusbench: An evaluation framework for time-series forecasting. InRecent Advances in Time Series Foundation Models Have We Reached the ’BERT Moment’?, 2025. URL https:// openreview.net/forum?id=3fMa060Ag5
work page 2025
-
[49]
U.S. Census Bureau. Manufacturers: Inventories to Sales Ratio [MNFCTRIRSA], 2026. URL https: //fred.stlouisfed.org/series/MNFCTRIRSA. Retrieved February 20, 2026
work page 2026
-
[50]
Manufacturers: Real Residential Property Prices for Germany [QDER628BIS], 2026
Bank for International Settlements. Manufacturers: Real Residential Property Prices for Germany [QDER628BIS], 2026. URL https://fred.stlouisfed.org/series/QDER628BIS. Retrieved Febru- ary 20, 2026
work page 2026
-
[51]
U.S. Bureau of Economic Analysis. Personal Consumption Expenditures: Chain-type Price Index [DPCERG3A086NBEA], 2026. URL https://fred.stlouisfed.org/series/DPCERG3A086NBEA. Retrieved February 20, 2026
work page 2026
-
[52]
U.S. Bureau of Labor Statistics. All Employees, Health Care [CES6562000101], 2026. URL https: //fred.stlouisfed.org/series/CES6562000101. Retrieved February 20, 2026
work page 2026
-
[53]
Paulo Cortez and Anbal Morais. Forest Fires. UCI Machine Learning Repository, 2007. DOI: https://doi.org/10.24432/C5D88D. A Dataset Wang et al. [5] implicitly defined a dataset of approximately 100 records as small-scale, and Gonen et al. [4], who proposed a data generation method for small-scale time-series data, utilised datasets of 1,000 records or few...
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.