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Alexandros Kalousis

14 accepted papers

2026

Noise-Guided Transport: Imitation Learning from Random Priors

ICML 2026poster

We consider imitation learning in the low-data regime, where only a limited number of expert demonstrations are available. In this setting, methods that rely on large-scale pretraining or high-capacity architectures can be difficult to apply, and efficiency with respect to demonstration data becomes…

Cited by 0SourceScholar
2026

Stein Diffusion Guidance: Training-Free Posterior Correction for Sampling Beyond High-Density Regions

ICML 2026poster

Training-free diffusion guidance offers a flexible framework for leveraging off-the-shelf classifiers without additional training. Yet, current approaches hinge on posterior approximations via Tweedie’s formula, which often yield unreliable guidance, particularly in low-density regions. Stochastic o…

Cited by 0SourceScholar
2025

GLAD: Improving Latent Graph Generative Modeling with Simple Quantization

AAAI 2025technical

Learning graph generative models over latent spaces has received less attention compared to models that operate on the original data space and has so far demonstrated lacklustre performance. We present GLAD a latent space graph generative model. Unlike most previous latent space graph generative mo…

2025

MING: A Functional Approach to Learning Molecular Generative Models

AISTATS 2025poster

Traditional molecule generation methods often rely on sequence- or graph-based representations, which can limit their expressive power or require complex permutation-equivariant architectures. This paper introduces a novel paradigm for learning molecule generative models based on functional represen…

Cited by 0SourcecodeScholar
2024

Mimicking Better by Matching the Approximate Action Distribution

ICML 2024poster

In this paper, we introduce MAAD, a novel, sample-efficient on-policy algorithm for Imitation Learning from Observations. MAAD utilizes a surrogate reward signal, which can be derived from various sources such as adversarial games, trajectory matching objectives, or optimal transport criteria. To co…

2023

Calibrating Neural Simulation-Based Inference with Differentiable Coverage Probability

NeurIPS 2023poster

Bayesian inference allows expressing the uncertainty of posterior belief under a probabilistic model given prior information and the likelihood of the evidence. Predominantly, the likelihood function is only implicitly established by a simulator posing the need for simulation-based inference (SBI).…

2023

Deep Grey-Box Modeling With Adaptive Data-Driven Models Toward Trustworthy Estimation of Theory-Driven Models

AISTATS 2023poster

The combination of deep neural nets and theory-driven models (deep grey-box models) can be advantageous due to the inherent robustness and interpretability of the theory-driven part. Deep grey-box models are usually learned with a regularized risk minimization to prevent a theory-driven part from be…

2021

Kanerva++: Extending the Kanerva Machine With Differentiable, Locally Block Allocated Latent Memory

ICLR 2021poster

Episodic and semantic memory are critical components of the human memory model. The theory of complementary learning systems (McClelland et al., 1995) suggests that the compressed representation produced by a serial event (episodic memory) is later restructured to build a more generalized form of re…

Cited by 4SourcePDFScholar
2021

Physics-Integrated Variational Autoencoders for Robust and Interpretable Generative Modeling

NeurIPS 2021poster

Integrating physics models within machine learning models holds considerable promise toward learning robust models with improved interpretability and abilities to extrapolate. In this work, we focus on the integration of incomplete physics models into deep generative models. In particular, we introd…

Cited by 89SourcePDFScholar
2020

Goal-directed Generation of Discrete Structures with Conditional Generative Models

NeurIPS 2020poster

Despite recent advances, goal-directed generation of structured discrete data remains challenging. For problems such as program synthesis (generating source code) and materials design (generating molecules), finding examples which satisfy desired constraints or exhibit desired properties is difficul…

Cited by 17SourcePDFScholar
2019

Sample-Efficient Imitation Learning via Generative Adversarial Nets

AISTATS 2019poster

GAIL is a recent successful imitation learning architecture that exploits the adversarial training procedure introduced in GANs. Albeit successful at generating behaviours similar to those demonstrated to the agent, GAIL suffers from a high sample complexity in the number of interactions it has to c…

2017

Regularising Non-linear Models Using Feature Side-information

ICML 2017poster

Very often features come with their own vectorial descriptions which provide detailed information about their properties. We refer to these vectorial descriptions as feature side-information. In the standard learning scenario, input is represented as a vector of features and the feature side-informa…

Cited by 17SourcePDFScholar
2015

Information Geometry and Minimum Description Length Networks

ICML 2015poster

We study parametric unsupervised mixture learning. We measure the loss of intrinsic information from the observations to complex mixture models, and then to simple mixture models. We present a geometric picture, where all these representations are regarded as free points in the space of probability…

Cited by 3SourcePDFScholar