Search Results for author: Tomáš Pevný

Found 18 papers, 13 papers with code

Leveraging Data Geometry to Mitigate CSM in Steganalysis

1 code implementation6 Oct 2023 Rony Abecidan, Vincent Itier, Jérémie Boulanger, Patrick Bas, Tomáš Pevný

By exploring a grid of processing pipelines fostering CSM, we discovered a geometrical metric based on the chordal distance between subspaces spanned by DCTr features, that exhibits high correlation with operational regret while being not affected by the cover-stego balance.

Steganalysis

NASimEmu: Network Attack Simulator & Emulator for Training Agents Generalizing to Novel Scenarios

2 code implementations26 May 2023 Jaromír Janisch, Tomáš Pevný, Viliam Lisý

Current frameworks for training offensive penetration testing agents with deep reinforcement learning struggle to produce agents that perform well in real-world scenarios, due to the reality gap in simulation-based frameworks and the lack of scalability in emulation-based frameworks.

Is AUC the best measure for practical comparison of anomaly detectors?

1 code implementation8 May 2023 Vít Škvára, Tomáš Pevný, Václav Šmídl

The area under receiver operating characteristics (AUC) is the standard measure for comparison of anomaly detectors.

Anomaly Detection

Using Set Covering to Generate Databases for Holistic Steganalysis

1 code implementation7 Nov 2022 Rony Abecidan, Vincent Itier, Jérémie Boulanger, Patrick Bas, Tomáš Pevný

Within an operational framework, covers used by a steganographer are likely to come from different sensors and different processing pipelines than the ones used by researchers for training their steganalysis models.

Domain Generalization Steganalysis

Explaining Classifiers Trained on Raw Hierarchical Multiple-Instance Data

no code implementations4 Aug 2022 Tomáš Pevný, Viliam Lisý, Branislav Bošanský, Petr Somol, Michal Pěchouček

Learning from raw data input, thus limiting the need for feature engineering, is a component of many successful applications of machine learning methods in various domains.

Feature Engineering Multiple Instance Learning

Fitting large mixture models using stochastic component selection

no code implementations NeurIPS 2021 Milan Papež, Tomáš Pevný, Václav Šmídl

The performance of our method is illustrated in a variety of synthetic and real-data contexts, considering deep models, such as mixtures of normalizing flows and sum-product (transform) networks.

Comparison of Anomaly Detectors: Context Matters

1 code implementation11 Dec 2020 Vít Škvára, Jan Franců, Matěj Zorek, Tomáš Pevný, Václav Šmídl

The objective of this comparison is twofold: to compare anomaly detection methods of various paradigms with focus on deep generative models, and identification of sources of variability that can yield different results.

Anomaly Detection Model Selection

Symbolic Relational Deep Reinforcement Learning based on Graph Neural Networks and Autoregressive Policy Decomposition

1 code implementation25 Sep 2020 Jaromír Janisch, Tomáš Pevný, Viliam Lisý

We focus on reinforcement learning (RL) in relational problems that are naturally defined in terms of objects, their relations, and object-centric actions.

reinforcement-learning Reinforcement Learning (RL) +1

Neural Power Units

4 code implementations NeurIPS 2020 Niklas Heim, Tomáš Pevný, Václav Šmídl

Conventional Neural Networks can approximate simple arithmetic operations, but fail to generalize beyond the range of numbers that were seen during training.

Rodent: Relevance determination in differential equations

no code implementations2 Dec 2019 Niklas Heim, Václav Šmídl, Tomáš Pevný

We aim to identify the generating, ordinary differential equation (ODE) from a set of trajectories of a partially observed system.

Classification with Costly Features in Hierarchical Deep Sets

1 code implementation20 Nov 2019 Jaromír Janisch, Tomáš Pevný, Viliam Lisý

In this work, we extend an existing deep reinforcement learning-based algorithm with hierarchical deep sets and hierarchical softmax, so that it can directly process this data.

Classification Classification with Costly Features +4

Classification with Costly Features as a Sequential Decision-Making Problem

2 code implementations5 Sep 2019 Jaromír Janisch, Tomáš Pevný, Viliam Lisý

This work focuses on a specific classification problem, where the information about a sample is not readily available, but has to be acquired for a cost, and there is a per-sample budget.

Classification Classification with Costly Features +4

Anomaly scores for generative models

1 code implementation28 May 2019 Václav Šmídl, Jan Bím, Tomáš Pevný

Reconstruction error is a prevalent score used to identify anomalous samples when data are modeled by generative models, such as (variational) auto-encoders or generative adversarial networks.

Approximation capability of neural networks on sets of probability measures and tree-structured data

no code implementations ICLR 2019 Tomáš Pevný, Vojtěch Kovařík

This paper extends the proof of density of neural networks in the space of continuous (or even measurable) functions on Euclidean spaces to functions on compact sets of probability measures.

AutoML

Classification with Costly Features using Deep Reinforcement Learning

1 code implementation20 Nov 2017 Jaromír Janisch, Tomáš Pevný, Viliam Lisý

We study a classification problem where each feature can be acquired for a cost and the goal is to optimize a trade-off between the expected classification error and the feature cost.

Classification Classification with Costly Features +5

Multiple Instance Learning for Malware Classification

2 code implementations5 May 2017 Jan Stiborek, Tomáš Pevný, Martin Rehák

This work addresses classification of unknown binaries executed in sandbox by modeling their interaction with system resources (files, mutexes, registry keys and communication with servers over the network) and error messages provided by the operating system, using vocabulary-based method from the multiple instance learning paradigm.

Cryptography and Security

Cannot find the paper you are looking for? You can Submit a new open access paper.