Search Results for author: Melih Kandemir

Found 25 papers, 9 papers with code

Calibrating Bayesian UNet++ for Sub-Seasonal Forecasting

no code implementations25 Mar 2024 Busra Asan, Abdullah Akgül, Alper Unal, Melih Kandemir, Gozde Unal

Seasonal forecasting is a crucial task when it comes to detecting the extreme heat and colds that occur due to climate change.

Probabilistic Actor-Critic: Learning to Explore with PAC-Bayes Uncertainty

no code implementations5 Feb 2024 Bahareh Tasdighi, Nicklas Werge, Yi-Shan Wu, Melih Kandemir

We introduce Probabilistic Actor-Critic (PAC), a novel reinforcement learning algorithm with improved continuous control performance thanks to its ability to mitigate the exploration-exploitation trade-off.

Continuous Control Decision Making +1

Demystifying the Myths and Legends of Nonconvex Convergence of SGD

no code implementations19 Oct 2023 Aritra Dutta, El Houcine Bergou, Soumia Boucherouite, Nicklas Werge, Melih Kandemir, Xin Li

Additionally, our analyses allow us to measure the density of the $\epsilon$-stationary points in the final iterates of SGD, and we recover the classical $O(\frac{1}{\sqrt{T}})$ asymptotic rate under various existing assumptions on the objective function and the bounds on the stochastic gradient.

EdVAE: Mitigating Codebook Collapse with Evidential Discrete Variational Autoencoders

1 code implementation9 Oct 2023 Gulcin Baykal, Melih Kandemir, Gozde Unal

We evidentially monitor the significance of attaining the probability distribution over the codebook embeddings, in contrast to softmax usage.

Sampling-Free Probabilistic Deep State-Space Models

no code implementations15 Sep 2023 Andreas Look, Melih Kandemir, Barbara Rakitsch, Jan Peters

Many real-world dynamical systems can be described as State-Space Models (SSMs).

Estimation of Counterfactual Interventions under Uncertainties

no code implementations15 Sep 2023 Juliane Weilbach, Sebastian Gerwinn, Melih Kandemir, Martin Fraenzle

This ambiguity is particularly challenging in continuous settings in which a continuum of explanations exist for the same observation.

counterfactual

BOF-UCB: A Bayesian-Optimistic Frequentist Algorithm for Non-Stationary Contextual Bandits

no code implementations7 Jul 2023 Nicklas Werge, Abdullah Akgül, Melih Kandemir

We propose a novel Bayesian-Optimistic Frequentist Upper Confidence Bound (BOF-UCB) algorithm for stochastic contextual linear bandits in non-stationary environments.

Decision Making Multi-Armed Bandits

Cheap and Deterministic Inference for Deep State-Space Models of Interacting Dynamical Systems

1 code implementation2 May 2023 Andreas Look, Melih Kandemir, Barbara Rakitsch, Jan Peters

Furthermore, we propose structured approximations to the covariance matrices of the Gaussian components in order to scale up to systems with many agents.

Autonomous Driving

PAC-Bayesian Soft Actor-Critic Learning

no code implementations30 Jan 2023 Bahareh Tasdighi, Abdullah Akgül, Kenny Kazimirzak Brink, Melih Kandemir

Actor-critic algorithms address the dual goals of reinforcement learning (RL), policy evaluation and improvement, via two separate function approximators.

Reinforcement Learning (RL)

PAC-Bayes Bounds for Bandit Problems: A Survey and Experimental Comparison

no code implementations29 Nov 2022 Hamish Flynn, David Reeb, Melih Kandemir, Jan Peters

On the one hand, we found that PAC-Bayes bounds are a useful tool for designing offline bandit algorithms with performance guarantees.

Decision Making

Learning Interacting Dynamical Systems with Latent Gaussian Process ODEs

1 code implementation24 May 2022 Çağatay Yıldız, Melih Kandemir, Barbara Rakitsch

We study time uncertainty-aware modeling of continuous-time dynamics of interacting objects.

Disentanglement

Continual Learning of Multi-modal Dynamics with External Memory

no code implementations2 Mar 2022 Abdullah Akgül, Gozde Unal, Melih Kandemir

We study the problem of fitting a model to a dynamical environment when new modes of behavior emerge sequentially.

Continual Learning

Traversing Time with Multi-Resolution Gaussian Process State-Space Models

no code implementations6 Dec 2021 Krista Longi, Jakob Lindinger, Olaf Duennbier, Melih Kandemir, Arto Klami, Barbara Rakitsch

These models have a natural interpretation as discretized stochastic differential equations, but inference for long sequences with fast and slow transitions is difficult.

Inferring the Structure of Ordinary Differential Equations

no code implementations5 Jul 2021 Juliane Weilbach, Sebastian Gerwinn, Christian Weilbach, Melih Kandemir

Understanding physical phenomena oftentimes means understanding the underlying dynamical system that governs observational measurements.

regression Symbolic Regression

Evidential Turing Processes

2 code implementations ICLR 2022 Melih Kandemir, Abdullah Akgül, Manuel Haussmann, Gozde Unal

A probabilistic classifier with reliable predictive uncertainties i) fits successfully to the target domain data, ii) provides calibrated class probabilities in difficult regions of the target domain (e. g.\ class overlap), and iii) accurately identifies queries coming out of the target domain and rejects them.

Image Classification Uncertainty Quantification

Differentiable Implicit Layers

no code implementations14 Oct 2020 Andreas Look, Simona Doneva, Melih Kandemir, Rainer Gemulla, Jan Peters

In this paper, we introduce an efficient backpropagation scheme for non-constrained implicit functions.

Model Predictive Control

Learning Partially Known Stochastic Dynamics with Empirical PAC Bayes

no code implementations17 Jun 2020 Manuel Haussmann, Sebastian Gerwinn, Andreas Look, Barbara Rakitsch, Melih Kandemir

Neural Stochastic Differential Equations model a dynamical environment with neural nets assigned to their drift and diffusion terms.

Time Series Prediction

A Deterministic Approximation to Neural SDEs

no code implementations16 Jun 2020 Andreas Look, Melih Kandemir, Barbara Rakitsch, Jan Peters

Our deterministic approximation of the transition kernel is applicable to both training and prediction.

Time Series Analysis Uncertainty Quantification +1

Differential Bayesian Neural Nets

no code implementations2 Dec 2019 Andreas Look, Melih Kandemir

Neural Ordinary Differential Equations (N-ODEs) are a powerful building block for learning systems, which extend residual networks to a continuous-time dynamical system.

Time Series Time Series Prediction

Deep Active Learning with Adaptive Acquisition

1 code implementation27 Jun 2019 Manuel Haussmann, Fred A. Hamprecht, Melih Kandemir

As active learning is a scarce data regime, we bootstrap from a well-known heuristic that filters the bulk of data points on which all heuristics would agree, and learn a policy to warp the top portion of this ranking in the most beneficial way for the character of a specific data distribution.

Active Learning Model Selection

Sampling-Free Variational Inference of Bayesian Neural Networks by Variance Backpropagation

1 code implementation19 May 2018 Manuel Haussmann, Fred A. Hamprecht, Melih Kandemir

We propose a new Bayesian Neural Net formulation that affords variational inference for which the evidence lower bound is analytically tractable subject to a tight approximation.

Variational Inference

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