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Tim Januschowski

15 accepted papers

2023

Coherent Probabilistic Forecasting of Temporal Hierarchies

AISTATS 2023poster

Forecasts at different time granularities are required in practice for addressing various business problems starting from short-term operational to medium-term tactical and to long-term strategic planning. These forecasting problems are usually treated independently by learning different ML models w…

Cited by 20SourcePDFScholar
2022

Multivariate Quantile Function Forecaster

AISTATS 2022poster

We propose Multivariate Quantile Function Forecaster (MQF2), a global probabilistic forecasting method constructed using a multivariate quantile function and investigate its application to multi-horizon forecasting. Prior approaches are either autoregressive, implicitly capturing the dependency stru…

2022

On the detrimental effect of invariances in the likelihood for variational inference

NeurIPS 2022accept

Variational Bayesian posterior inference often requires simplifying approximations such as mean-field parametrisation to ensure tractability. However, prior work has associated the variational mean-field approximation for Bayesian neural networks with underfitting in the case of small datasets or la…

Cited by 10SourcePDFScholar
2022

PSA-GAN: Progressive Self Attention GANs for Synthetic Time Series

ICLR 2022poster

Realistic synthetic time series data of sufficient length enables practical applications in time series modeling tasks, such as forecasting, but remains a challenge. In this paper we present PSA-GAN, a generative adversarial network (GAN) that generates long time series samples of high quality using…

2021

Deep Explicit Duration Switching Models for Time Series

NeurIPS 2021poster

Many complex time series can be effectively subdivided into distinct regimes that exhibit persistent dynamics. Discovering the switching behavior and the statistical patterns in these regimes is important for understanding the underlying dynamical system. We propose the Recurrent Explicit Duration S…

2021

Detecting Anomalous Event Sequences with Temporal Point Processes

NeurIPS 2021poster

Automatically detecting anomalies in event data can provide substantial value in domains such as healthcare, DevOps, and information security. In this paper, we frame the problem of detecting anomalous continuous-time event sequences as out-of-distribution (OOD) detection for temporal point processe…

Cited by 18SourcePDFScholar
2021

End-to-End Learning of Coherent Probabilistic Forecasts for Hierarchical Time Series

ICML 2021spotlight

This paper presents a novel approach for hierarchical time series forecasting that produces coherent, probabilistic forecasts without requiring any explicit post-processing reconciliation. Unlike the state-of-the-art, the proposed method simultaneously learns from all time series in the hierarchy an…

Cited by 91SourcePDFScholar
2021

Neural Flows: Efficient Alternative to Neural ODEs

NeurIPS 2021poster

Neural ordinary differential equations describe how values change in time. This is the reason why they gained importance in modeling sequential data, especially when the observations are made at irregular intervals. In this paper we propose an alternative by directly modeling the solution curves - t…

2021

Neural Temporal Point Processes: A Review

IJCAI 2021poster

Temporal point processes (TPP) are probabilistic generative models for continuous-time event sequences. Neural TPPs combine the fundamental ideas from point process literature with deep learning approaches, thus enabling construction of flexible and efficient models. The topic of neural TPPs has att…

Cited by 120SourcePDFScholar
2021

Online false discovery rate control for anomaly detection in time series

NeurIPS 2021poster

This article proposes novel rules for false discovery rate control (FDRC) geared towards online anomaly detection in time series. Online FDRC rules allow to control the properties of a sequence of statistical tests. In the context of anomaly detection, the null hypothesis is that an observation is n…

Cited by 18SourcePDFScholar
2020

Normalizing Kalman Filters for Multivariate Time Series Analysis

NeurIPS 2020poster

This paper tackles the modelling of large, complex and multivariate time series panels in a probabilistic setting. To this extent, we present a novel approach reconciling classical state space models with deep learning methods. By augmenting state space models with normalizing flows, we mitigate imp…

Cited by 155SourcePDFScholar
2019

Deep Factors for Forecasting

ICML 2019oral

Producing probabilistic forecasts for large collections of similar and/or dependent time series is a practically highly relevant, yet challenging task. Classical time series models fail to capture complex patterns in the data and multivariate techniques struggle to scale to large problem sizes, but…

Cited by 247SourcePDFScholar
2019

Probabilistic Forecasting with Spline Quantile Function RNNs

AISTATS 2019poster

In this paper, we propose a flexible method for probabilistic modeling with conditional quantile functions using monotonic regression splines. The shape of the spline is parameterized by a neural network whose parameters are learned by minimizing the continuous ranked probability score. Within this…

Cited by 216SourcePDFScholar
2018

Deep State Space Models for Time Series Forecasting

NeurIPS 2018poster

We present a novel approach to probabilistic time series forecasting that combines state space models with deep learning. By parametrizing a per-time-series linear state space model with a jointly-learned recurrent neural network, our method retains desired properties of state space models such as d…

Cited by 980SourcePDFScholar