Inductive Learning
A Self-supervised Learning Method for Raman Spectroscopy based on Masked Autoencoders
Ren, Pengju, Zhou, Ri-gui, Li, Yaochong
Raman spectroscopy serves as a powerful and reliable tool for analyzing the chemical information of substances. The integration of Raman spectroscopy with deep learning methods enables rapid qualitative and quantitative analysis of materials. Most existing approaches adopt supervised learning methods. Although supervised learning has achieved satisfactory accuracy in spectral analysis, it is still constrained by costly and limited well-annotated spectral datasets for training. When spectral annotation is challenging or the amount of annotated data is insufficient, the performance of supervised learning in spectral material identification declines. In order to address the challenge of feature extraction from unannotated spectra, we propose a self-supervised learning paradigm for Raman Spectroscopy based on a Masked AutoEncoder, termed SMAE. SMAE does not require any spectral annotations during pre-training. By randomly masking and then reconstructing the spectral information, the model learns essential spectral features. The reconstructed spectra exhibit certain denoising properties, improving the signal-to-noise ratio (SNR) by more than twofold. Utilizing the network weights obtained from masked pre-training, SMAE achieves clustering accuracy of over 80% for 30 classes of isolated bacteria in a pathogenic bacterial dataset, demonstrating significant improvements compared to classical unsupervised methods and other state-of-the-art deep clustering methods. After fine-tuning the network with a limited amount of annotated data, SMAE achieves an identification accuracy of 83.90% on the test set, presenting competitive performance against the supervised ResNet (83.40%).
MAGIC: Near-Optimal Data Attribution for Deep Learning
Ilyas, Andrew, Engstrom, Logan
A fundamental problem when building machine learning syste ms is to predict counterfactuals about model behavior. For example, scaling laws [ KMH+20; Has21; MRB+23 ] aim to predict the performance of systems trained with more data and more co mpute than is currently available; interpretability techniques [ KWG+18 ] predict how models behave under counterfactual inputs. Analogously, in this work we study predictive data attribution (or datamodeling [ IPE+22 ]), where the goal is to predict how a model would behave if it had been tr ained on a different dataset. This well-studied problem encompasses, e.g., estimating the ef fect (on the resulting trained model's predictions) of modifying a training example [ KL17 ], removing a group of training examples [ KAT+19; BNL+22; PGI+23 ], or adding entire training data sources [ LSZ+24 ]. Predictive data attribution in large-scale settings is cha llenging: it requires simulating training a model on a different dataset without actually training [ GWP+23; IGE+24 ]. In "classical" settings--when learning corresponds to minimizing a convex loss--statistical tools like the influence function [ Ham47 ] allow us to accurately and efficiently estimate how differen t training data choices change trained model predictions [ RM18; KAT+19; GSL+19 ]. However, in the non-convex settings that are ubiquitous in natural domains like langua ge/vision, current methods are less effective. Indeed, the best existing methods produce estimat es that typically (a) only moderately correlate with the ground truth [ BPF21; BNL+22; PGI+23 ] and (b) incur large absolute error [ BNL+22 ].
Describe Anything: Detailed Localized Image and Video Captioning
Lian, Long, Ding, Yifan, Ge, Yunhao, Liu, Sifei, Mao, Hanzi, Li, Boyi, Pavone, Marco, Liu, Ming-Yu, Darrell, Trevor, Yala, Adam, Cui, Yin
Generating detailed and accurate descriptions for specific regions in images and videos remains a fundamental challenge for vision-language models. We introduce the Describe Anything Model (DAM), a model designed for detailed localized captioning (DLC). DAM preserves both local details and global context through two key innovations: a focal prompt, which ensures high-resolution encoding of targeted regions, and a localized vision backbone, which integrates precise localization with its broader context. To tackle the scarcity of high-quality DLC data, we propose a Semi-supervised learning (SSL)-based Data Pipeline (DLC-SDP). DLC-SDP starts with existing segmentation datasets and expands to unlabeled web images using SSL. We introduce DLC-Bench, a benchmark designed to evaluate DLC without relying on reference captions. DAM sets new state-of-the-art on 7 benchmarks spanning keyword-level, phrase-level, and detailed multi-sentence localized image and video captioning.
Invariant Learning with Annotation-free Environments
Le, Phuong Quynh, Seifert, Christin, Schlötterer, Jörg
Invariant learning is a promising approach to improve domain generalization compared to Empirical Risk Minimization (ERM). However, most invariant learning methods rely on the assumption that training examples are pre-partitioned into different known environments. We instead infer environments without the need for additional annotations, motivated by observations of the properties within the representation space of a trained ERM model. We show the preliminary effectiveness of our approach on the ColoredMNIST benchmark, achieving performance comparable to methods requiring explicit environment labels and on par with an annotation-free method that poses strong restrictions on the ERM reference model.
Locate 3D: Real-World Object Localization via Self-Supervised Learning in 3D
Arnaud, Sergio, McVay, Paul, Martin, Ada, Majumdar, Arjun, Jatavallabhula, Krishna Murthy, Thomas, Phillip, Partsey, Ruslan, Dugas, Daniel, Gejji, Abha, Sax, Alexander, Berges, Vincent-Pierre, Henaff, Mikael, Jain, Ayush, Cao, Ang, Prasad, Ishita, Kalakrishnan, Mrinal, Rabbat, Michael, Ballas, Nicolas, Assran, Mido, Maksymets, Oleksandr, Rajeswaran, Aravind, Meier, Franziska
We present LOCATE 3D, a model for localizing objects in 3D scenes from referring expressions like "the small coffee table between the sofa and the lamp." LOCATE 3D sets a new state-of-the-art on standard referential grounding benchmarks and showcases robust generalization capabilities. Notably, LOCATE 3D operates directly on sensor observation streams (posed RGB-D frames), enabling real-world deployment on robots and AR devices. Key to our approach is 3D-JEPA, a novel self-supervised learning (SSL) algorithm applicable to sensor point clouds. It takes as input a 3D pointcloud featurized using 2D foundation models (CLIP, DINO). Subsequently, masked prediction in latent space is employed as a pretext task to aid the self-supervised learning of contextualized pointcloud features. Once trained, the 3D-JEPA encoder is finetuned alongside a language-conditioned decoder to jointly predict 3D masks and bounding boxes. Additionally, we introduce LOCATE 3D DATASET, a new dataset for 3D referential grounding, spanning multiple capture setups with over 130K annotations. This enables a systematic study of generalization capabilities as well as a stronger model.
Spectral Algorithms under Covariate Shift
Fan, Jun, Guo, Zheng-Chu, Shi, Lei
Spectral algorithms leverage spectral regularization techniques to analyze and process data, providing a flexible framework for addressing supervised learning problems. To deepen our understanding of their performance in real-world scenarios where the distributions of training and test data may differ, we conduct a rigorous investigation into the convergence behavior of spectral algorithms under distribution shifts, specifically within the framework of reproducing kernel Hilbert spaces. Our study focuses on the case of covariate shift. In this scenario, the marginal distributions of the input data differ between the training and test datasets, while the conditional distribution of the output given the input remains unchanged. Under this setting, we analyze the generalization error of spectral algorithms and show that they achieve minimax optimality when the density ratios between the training and test distributions are uniformly bounded. However, we also identify a critical limitation: when the density ratios are unbounded, the spectral algorithms may become suboptimal. To address this limitation, we propose a weighted spectral algorithm that incorporates density ratio information into the learning process. Our theoretical analysis shows that this weighted approach achieves optimal capacity-independent convergence rates. Furthermore, by introducing a weight clipping technique, we demonstrate that the convergence rates of the weighted spectral algorithm can approach the optimal capacity-dependent convergence rates arbitrarily closely. This improvement resolves the suboptimality issue in unbounded density ratio scenarios and advances the state-of-the-art by refining existing theoretical results.
An Empirically Grounded Identifiability Theory Will Accelerate Self-Supervised Learning Research
Reizinger, Patrik, Balestriero, Randall, Klindt, David, Brendel, Wieland
Self-Supervised Learning (SSL) powers many current AI systems. As research interest and investment grow, the SSL design space continues to expand. The Platonic view of SSL, following the Platonic Representation Hypothesis (PRH), suggests that despite different methods and engineering approaches, all representations converge to the same Platonic ideal. However, this phenomenon lacks precise theoretical explanation. By synthesizing evidence from Identifiability Theory (IT), we show that the PRH can emerge in SSL. However, current IT cannot explain SSL's empirical success. To bridge the gap between theory and practice, we propose expanding IT into what we term Singular Identifiability Theory (SITh), a broader theoretical framework encompassing the entire SSL pipeline. SITh would allow deeper insights into the implicit data assumptions in SSL and advance the field towards learning more interpretable and generalizable representations. We highlight three critical directions for future research: 1) training dynamics and convergence properties of SSL; 2) the impact of finite samples, batch size, and data diversity; and 3) the role of inductive biases in architecture, augmentations, initialization schemes, and optimizers.
Balancing Graph Embedding Smoothness in Self-Supervised Learning via Information-Theoretic Decomposition
Self-supervised learning (SSL) in graphs has garnered significant attention, particularly in employing Graph Neural Networks (GNNs) with pretext tasks initially designed for other domains, such as contrastive learning and feature reconstruction. However, it remains uncertain whether these methods effectively reflect essential graph properties, precisely representation similarity with its neighbors. We observe that existing methods position opposite ends of a spectrum driven by the graph embedding smoothness, with each end corresponding to outperformance on specific downstream tasks. Decomposing the SSL objective into three terms via an information-theoretic framework with a neighbor representation variable reveals that this polarization stems from an imbalance among the terms, which existing methods may not effectively maintain. Further insights suggest that balancing between the extremes can lead to improved performance across a wider range of downstream tasks. A framework, BSG (Balancing Smoothness in Graph SSL), introduces novel loss functions designed to supplement the representation quality in graph-based SSL by balancing the derived three terms: neighbor loss, minimal loss, and divergence loss. We present a theoretical analysis of the effects of these loss functions, highlighting their significance from both the SSL and graph smoothness perspectives. Extensive experiments on multiple real-world datasets across node classification and link prediction consistently demonstrate that BSG achieves state-of-the-art performance, outperforming existing methods. Our implementation code is available at https://github.com/steve30572/BSG.
Independence Is Not an Issue in Neurosymbolic AI
Faronius, Håkan Karlsson, Martires, Pedro Zuidberg Dos
A popular approach to neurosymbolic AI is to take the output of the last layer of a neural network, e.g. a softmax activation, and pass it through a sparse computation graph encoding certain logical constraints one wishes to enforce. This induces a probability distribution over a set of random variables, which happen to be conditionally independent of each other in many commonly used neurosymbolic AI models. Such conditionally independent random variables have been deemed harmful as their presence has been observed to co-occur with a phenomenon dubbed deterministic bias, where systems learn to determinis-tically prefer one of the valid solutions from the solution space over the others. We provide evidence contesting this conclusion and show that the phenomenon of deterministic bias is an artifact of improperly applying neurosymbolic AI. Keywords: neurosymbolic AI partial label learning 1 Introduction Neurosymbolic (NeSy) AI is an approach to AI which seeks to combine logic and neural networks [13].
Watch: New speed climbing record set in the Swiss Alps
A Swiss and Austrian climbing pair have shattered the speed record for completing the daunting north faces of a famed trio of Swiss mountains - the Eiger, Mönch and Jungfrau. Switzerland's Nicolas Hojac and Austria's Philipp Brugger shaved nearly ten hours off the previous record set more than two decades ago.