São Paulo
Drift-Resilient TabPFN: In-Context Learning Temporal Distribution Shifts on Tabular Data
Kai Helli, David Schnurr, Noah Hollmann, Samuel Müller, Frank Hutter
While most ML models expect independent and identically distributed data, this assumption is often violated in real-world scenarios due to distribution shifts, resulting in the degradation of machine learning model performance. Until now, no tabular method has consistently outperformed classical supervised learning, which ignores these shifts. To address temporal distribution shifts, we present Drift-Resilient TabPFN, a fresh approach based on In-Context Learning with a Prior-Data Fitted Network that learns the learning algorithm itself: it accepts the entire training dataset as input and makes predictions on the test set in a single forward pass. Specifically, it learns to approximate Bayesian inference on synthetic datasets drawn from a prior that specifies the model's inductive bias. This prior is based on structural causal models (SCM), which gradually shift over time.
Unveiling ECC Vulnerabilities: LSTM Networks for Operation Recognition in Side-Channel Attacks
Battistello, Alberto, Bertoni, Guido, Corrias, Michele, Nava, Lorenzo, Rusconi, Davide, Zoia, Matteo, Pierazzi, Fabio, Lanzi, Andrea
We propose a novel approach for performing side-channel attacks on elliptic curve cryptography. Unlike previous approaches and inspired by the ``activity detection'' literature, we adopt a long-short-term memory (LSTM) neural network to analyze a power trace and identify patterns of operation in the scalar multiplication algorithm performed during an ECDSA signature, that allows us to recover bits of the ephemeral key, and thus retrieve the signer's private key. Our approach is based on the fact that modular reductions are conditionally performed by micro-ecc and depend on key bits. We evaluated the feasibility and reproducibility of our attack through experiments in both simulated and real implementations. We demonstrate the effectiveness of our attack by implementing it on a real target device, an STM32F415 with the micro-ecc library, and successfully compromise it. Furthermore, we show that current countermeasures, specifically the coordinate randomization technique, are not sufficient to protect against side channels. Finally, we suggest other approaches that may be implemented to thwart our attack.
The Robustness of Structural Features in Species Interaction Networks
Fard, Sanaz Hasanzadeh, Dolson, Emily
Species interaction networks are a powerful tool for describing ecological communities; they typically contain nodes representing species, and edges representing interactions between those species. For the purposes of drawing abstract inferences about groups of similar networks, ecologists often use graph topology metrics to summarize structural features. However, gathering the data that underlies these networks is challenging, which can lead to some interactions being missed. Thus, it is important to understand how much different structural metrics are affected by missing data. To address this question, we analyzed a database of 148 real-world bipartite networks representing four different types of species interactions (pollination, host-parasite, plant-ant, and seed-dispersal). For each network, we measured six different topological properties: number of connected components, variance in node betweenness, variance in node PageRank, largest Eigenvalue, the number of non-zero Eigenvalues, and community detection as determined by four different algorithms. We then tested how these properties change as additional edges -- representing data that may have been missed -- are added to the networks. We found substantial variation in how robust different properties were to the missing data. For example, the Clauset-Newman-Moore and Louvain community detection algorithms showed much more gradual change as edges were added than the label propagation and Girvan-Newman algorithms did, suggesting that the former are more robust. Robustness also varied for some metrics based on interaction type. These results provide a foundation for selecting network properties to use when analyzing messy ecological network data.
Can AI and automated planes help prevent plane crashes?
More than 100 people have been killed in air crashes this year already, including in a midair collision between a commercial airliner and a helicopter near Washington, DC, and a plane crashing into a bus on a Sao Paulo street. The fatal incidents in the first two months of the new year came after last year was declared one of the deadliest in aviation history with at least 318 deaths in 11 civilian airplane crashes, including two incidents in the last week of December. While fatal air crashes are rare, they attract extraordinary attention, often reinstilling the fear of flying. At least 25 million adults in the United States alone have a fear of flying, according to the Cleveland Clinic. The fear is often exacerbated not just by the crashes but also incidents like emergency landings, a door blowing off a plane and aircraft skidding off runways.
Building a Cognitive Twin Using a Distributed Cognitive System and an Evolution Strategy
Gibaut, Wandemberg, Gudwin, Ricardo
Approximately at the same time, based on the ideas This work proposes an approach that uses an evolutionary presented by Newell, Rosenbloom and Laird (1989), Laird algorithm along traditional Machine Learning methods released early versions of the SOAR cognitive architecture to build a digital, distributed cognitive agent capable of (Laird and Rosenbloom, 1996; Laird, 2012). By the end of emulating the potential actions (input-output behavior) of the 1990s, a large group of researchers involved in the Simulation a user while allowing further analysis and experimentation of Adaptive Behavior shaped the concept of Cognitive - at a certain level - of its internal structures. We focus Architecture as an essential set of structures and processes on the usage of simple devices and the automation of this necessary for the generation of a computational, cognitive building process, rather than manually designing the agent.
PublicHearingBR: A Brazilian Portuguese Dataset of Public Hearing Transcripts for Summarization of Long Documents
Fernandes, Leandro Carísio, Dobins, Guilherme Zeferino Rodrigues, Lotufo, Roberto, Pereira, Jayr Alencar
This paper introduces PublicHearingBR, a Brazilian Portuguese dataset designed for summarizing long documents. The dataset consists of transcripts of public hearings held by the Brazilian Chamber of Deputies, paired with news articles and structured summaries containing the individuals participating in the hearing and their statements or opinions. The dataset supports the development and evaluation of long document summarization systems in Portuguese. Our contributions include the dataset, a hybrid summarization system to establish a baseline for future studies, and a discussion on evaluation metrics for summarization involving large language models, addressing the challenge of hallucination in the generated summaries. As a result of this discussion, the dataset also provides annotated data that can be used in Natural Language Inference tasks in Portuguese.
Interactive Event Sifting using Bayesian Graph Neural Networks
Nascimento, José, Jacobs, Nathan, Rocha, Anderson
Forensic analysts often use social media imagery and texts to understand important events. A primary challenge is the initial sifting of irrelevant posts. This work introduces an interactive process for training an event-centric, learning-based multimodal classification model that automates sanitization. We propose a method based on Bayesian Graph Neural Networks (BGNNs) and evaluate active learning and pseudo-labeling formulations to reduce the number of posts the analyst must manually annotate. Our results indicate that BGNNs are useful for social-media data sifting for forensics investigations of events of interest, the value of active learning and pseudo-labeling varies based on the setting, and incorporating unlabelled data from other events improves performance.
Best Practices for Responsible Machine Learning in Credit Scoring
Valdrighi, Giovani, Ribeiro, Athyrson M., Pereira, Jansen S. B., Guardieiro, Vitoria, Hendricks, Arthur, Filho, Décio Miranda, Garcia, Juan David Nieto, Bocca, Felipe F., Veronese, Thalita B., Wanner, Lucas, Raimundo, Marcos Medeiros
For individuals and families, access to affordable credit is essential as protection against financial volatility, financing and education, pursuing business opportunities, and building equity. From the lender's perspective, there is a delicate balance between improving access to credit and higher costs due to defaults on payments. Creating responsible credit concession models requires maintaining this balance [Kozodoi et al., 2022] while ensuring fair outcomes across different groups of individuals, improving access, and helping applicants understand factors that influence rejection so that they can take action to improve their credit potential. Credit concession models are created using a variety of data, such as employment history (for example, occupation and income), demographic data (such as age, marital status, and education), and financial data (for example, checking account balance, credit card usage, and bill payment history). Given these features, models such as logistic regression, gradient boosting, and decision trees can be trained to predict whether a new customer will default on a loan over a period of time [Louzada et al., 2016].
A Large Dataset of Spontaneous Speech with the Accent Spoken in S\~ao Paulo for Automatic Speech Recognition Evaluation
Lima, Rodrigo, Leal, Sidney Evaldo, Junior, Arnaldo Candido, Aluísio, Sandra Maria
We present a freely available spontaneous speech corpus for the Brazilian Portuguese language and report preliminary automatic speech recognition (ASR) results, using both the Wav2Vec2-XLSR-53 and Distil-Whisper models fine-tuned and trained on our corpus. The NURC-SP Audio Corpus comprises 401 different speakers (204 females, 197 males) with a total of 239.30 hours of transcribed audio recordings. To the best of our knowledge, this is the first large Paulistano accented spontaneous speech corpus dedicated to the ASR task in Portuguese. We first present the design and development procedures of the NURC-SP Audio Corpus, and then describe four ASR experiments in detail. The experiments demonstrated promising results for the applicability of the corpus for ASR. Specifically, we fine-tuned two versions of Wav2Vec2-XLSR-53 model, trained a Distil-Whisper model using our dataset with labels determined by Whisper Large-V3 model, and fine-tuned this Distil-Whisper model with our corpus. Our best results were the Distil-Whisper fine-tuned over NURC-SP Audio Corpus with a WER of 24.22% followed by a fine-tuned versions of Wav2Vec2-XLSR-53 model with a WER of 33.73%, that is almost 10% point worse than Distil-Whisper's. To enable experiment reproducibility, we share the NURC-SP Audio Corpus dataset, pre-trained models, and training recipes in Hugging-Face and Github repositories.
Gay Brazilians targeted in deadly stickups, lured by dating apps
It was June 12, Lover's Day in Brazil. Leo Nunes, 24, had spent a few days talking to someone he met on Hornet, a popular gay dating app, before arranging their first encounter in Sao Paulo's middle-class Sacoma neighborhood. A security camera captured the moment that two men on a motorcycle showed up in the alley where he was waiting, grabbed his phone and shot him dead. The Nunes family, who shared details of the investigation with Reuters, said one suspect had been arrested. Sao Paulo police said they are investigating the shooting as a robbery resulting in a homicide, but did not provide further information or confirm if there had been an arrest.