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Found 55 papers, 8 papers with code
A Latent Variable Model Approach to PMI-based Word Embeddings
Semantic word embeddings represent the meaning of a word via a vector, and are created by diverse methods.
Linear Algebraic Structure of Word Senses, with Applications to Polysemy
A novel aspect of our technique is that each extracted word sense is accompanied by one of about 2000 "discourse atoms" that gives a succinct description of which other words co-occur with that word sense.
Domain-Adjusted Regression or: ERM May Already Learn Features Sufficient for Out-of-Distribution Generalization
Towards this end, we introduce Domain-Adjusted Regression (DARE), a convex objective for learning a linear predictor that is provably robust under a new model of distribution shift.
Contrasting the landscape of contrastive and non-contrastive learning
Some recent works however have shown promising results for non-contrastive learning, which does not require negative samples.
Empirical Study of the Benefits of Overparameterization in Learning Latent Variable Models
One of the most surprising and exciting discoveries in supervised learning was the benefit of overparameterization (i. e. training a very large model) to improving the optimization landscape of a problem, with minimal effect on statistical performance (i. e. generalization).
Automated WordNet Construction Using Word Embeddings
To evaluate our method we construct two 600-word testsets for word-to-synset matching in French and Russian using native speakers and evaluate the performance of our method along with several other recent approaches.
How Do Transformers Learn Topic Structure: Towards a Mechanistic Understanding
While the successes of transformers across many domains are indisputable, accurate understanding of the learning mechanics is still largely lacking.
Representational Power of ReLU Networks and Polynomial Kernels: Beyond Worst-Case Analysis
We give almost-tight bounds on the performance of both neural networks and low degree polynomials for this problem.
Theoretical limitations of Encoder-Decoder GAN architectures
Encoder-decoder GANs architectures (e. g., BiGAN and ALI) seek to add an inference mechanism to the GANs setup, consisting of a small encoder deep net that maps data-points to their succinct encodings.
Beyond Log-concavity: Provable Guarantees for Sampling Multi-modal Distributions using Simulated Tempering Langevin Monte Carlo
We analyze this Markov chain for the canonical multi-modal distribution: a mixture of gaussians (of equal variance).
Provable benefits of representation learning
There is general consensus that learning representations is useful for a variety of reasons, e. g. efficient use of labeled data (semi-supervised learning), transfer learning and understanding hidden structure of data.
On the ability of neural nets to express distributions
We take a first cut at explaining the expressivity of multilayer nets by giving a sufficient criterion for a function to be approximable by a neural network with $n$ hidden layers.
Extending and Improving Wordnet via Unsupervised Word Embeddings
Our methods require very few linguistic resources, thus being applicable for Wordnet construction in low-resources languages, and may further be applied to sense clustering and other Wordnet improvements.
Provable learning of Noisy-or Networks
Many machine learning applications use latent variable models to explain structure in data, whereby visible variables (= coordinates of the given datapoint) are explained as a probabilistic function of some hidden variables.
Recovery guarantee of weighted low-rank approximation via alternating minimization
We show that the properties only need to hold in an average sense and can be achieved by the clipping step.
Recovery Guarantee of Non-negative Matrix Factorization via Alternating Updates
Non-negative matrix factorization is a popular tool for decomposing data into feature and weight matrices under non-negativity constraints.
Approximate maximum entropy principles via Goemans-Williamson with applications to provable variational methods
The well known maximum-entropy principle due to Jaynes, which states that given mean parameters, the maximum entropy distribution matching them is in an exponential family, has been very popular in machine learning due to its "Occam's razor" interpretation.
How to calculate partition functions using convex programming hierarchies: provable bounds for variational methods
We make use of recent tools in combinatorial optimization: the Sherali-Adams and Lasserre convex programming hierarchies, in combination with variational methods to get algorithms for calculating partition functions in these families.
Label optimal regret bounds for online local learning
We resolve an open question from (Christiano, 2014b) posed in COLT'14 regarding the optimal dependency of the regret achievable for online local learning on the size of the label set.
On some provably correct cases of variational inference for topic models
The assumptions on the topic priors are related to the well known Dirichlet prior, introduced to the area of topic modeling by (Blei et al., 2003).
Approximability of Discriminators Implies Diversity in GANs
Our preliminary experiments show that on synthetic datasets the test IPM is well correlated with KL divergence or the Wasserstein distance, indicating that the lack of diversity in GANs may be caused by the sub-optimality in optimization instead of statistical inefficiency.
Mean-field approximation, convex hierarchies, and the optimality of correlation rounding: a unified perspective
More precisely, we show that the mean-field approximation is within $O((n\|J\|_{F})^{2/3})$ of the free energy, where $\|J\|_F$ denotes the Frobenius norm of the interaction matrix of the Ising model.
Simulated Tempering Langevin Monte Carlo II: An Improved Proof using Soft Markov Chain Decomposition
Previous approaches rely on decomposing the state space as a partition of sets, while our approach can be thought of as decomposing the stationary measure as a mixture of distributions (a "soft partition").
Algorithms and matching lower bounds for approximately-convex optimization
In recent years, a rapidly increasing number of applications in practice requires solving non-convex objectives, like training neural networks, learning graphical models, maximum likelihood estimation etc.
The Comparative Power of ReLU Networks and Polynomial Kernels in the Presence of Sparse Latent Structure
We give an almost-tight theoretical analysis of the performance of both neural networks and polynomials for this problem, as well as verify our theory with simulations.
Do GANs learn the distribution? Some Theory and Empirics
Using this evidence is presented that well-known GANs approaches do learn distributions of fairly low support.
Sum-of-squares meets square loss: Fast rates for agnostic tensor completion
In agnostic tensor completion, we make no assumption on the rank of the unknown tensor, but attempt to predict unknown entries as well as the best rank-$r$ tensor.
Fast Convergence for Langevin Diffusion with Manifold Structure
In this paper, we focus on an aspect of nonconvexity relevant for modern machine learning applications: existence of invariances (symmetries) in the function f, as a result of which the distribution p will have manifolds of points with equal probability.
On Learning Language-Invariant Representations for Universal Machine Translation
The goal of universal machine translation is to learn to translate between any pair of languages, given a corpus of paired translated documents for \emph{a small subset} of all pairs of languages.
Efficient sampling from the Bingham distribution
We give a algorithm for exact sampling from the Bingham distribution $p(x)\propto \exp(x^\top A x)$ on the sphere $\mathcal S^{d-1}$ with expected runtime of $\operatorname{poly}(d, \lambda_{\max}(A)-\lambda_{\min}(A))$.
Representational aspects of depth and conditioning in normalizing flows
Normalizing flows are among the most popular paradigms in generative modeling, especially for images, primarily because we can efficiently evaluate the likelihood of a data point.
The Risks of Invariant Risk Minimization
We furthermore present the very first results in the non-linear regime: we demonstrate that IRM can fail catastrophically unless the test data are sufficiently similar to the training distribution--this is precisely the issue that it was intended to solve.
An Online Learning Approach to Interpolation and Extrapolation in Domain Generalization
A popular assumption for out-of-distribution generalization is that the training data comprises sub-datasets, each drawn from a distinct distribution; the goal is then to "interpolate" these distributions and "extrapolate" beyond them -- this objective is broadly known as domain generalization.
Parametric Complexity Bounds for Approximating PDEs with Neural Networks
Recent experiments have shown that deep networks can approximate solutions to high-dimensional PDEs, seemingly escaping the curse of dimensionality.
Contrastive learning of strong-mixing continuous-time stochastic processes
Contrastive learning is a family of self-supervised methods where a model is trained to solve a classification task constructed from unlabeled data.
The Limitations of Limited Context for Constituency Parsing
Concretely, we ground this question in the sandbox of probabilistic context-free-grammars (PCFGs), and identify a key aspect of the representational power of these approaches: the amount and directionality of context that the predictor has access to when forced to make parsing decision.
Iterative Feature Matching: Toward Provable Domain Generalization with Logarithmic Environments
Domain generalization aims at performing well on unseen test environments with data from a limited number of training environments.
Universal Approximation for Log-concave Distributions using Well-conditioned Normalizing Flows
As ill-conditioned Jacobians are an obstacle for likelihood-based training, the fundamental question remains: which distributions can be approximated using well-conditioned affine coupling flows?
The Effects of Invertibility on the Representational Complexity of Encoders in Variational Autoencoders
Training and using modern neural-network based latent-variable generative models (like Variational Autoencoders) often require simultaneously training a generative direction along with an inferential(encoding) direction, which approximates the posterior distribution over the latent variables.
Analyzing and Improving the Optimization Landscape of Noise-Contrastive Estimation
Noise-contrastive estimation (NCE) is a statistically consistent method for learning unnormalized probabilistic models.
Universal Approximation Using Well-Conditioned Normalizing Flows
As ill-conditioned Jacobians are an obstacle for likelihood-based training, the fundamental question remains: which distributions can be approximated using well-conditioned affine coupling flows?
Benefits of Overparameterization in Single-Layer Latent Variable Generative Models
One of the most surprising and exciting discoveries in supervising learning was the benefit of overparameterization (i. e. training a very large model) to improving the optimization landscape of a problem, with minimal effect on statistical performance (i. e. generalization).
Fast Convergence for Langevin with Matrix Manifold Structure
In this paper, we study one aspect of nonconvexity relevant for modern machine learning applications: existence of invariances (symmetries) in the function f, as a result of which the distribution p will have manifolds of points with equal probability.
Variational autoencoders in the presence of low-dimensional data: landscape and implicit bias
Recent work by Dai and Wipf (2020) proposes a two-stage training algorithm for VAEs, based on a conjecture that in standard VAE training the generator will converge to a solution with 0 variance which is correctly supported on the ground truth manifold.
Masked prediction tasks: a parameter identifiability view
This lens is undoubtedly very interesting, but suffers from the problem that there isn't a "canonical" set of downstream tasks to focus on -- in practice, this problem is usually resolved by competing on the benchmark dataset du jour.
Sampling Approximately Low-Rank Ising Models: MCMC meets Variational Methods
We consider Ising models on the hypercube with a general interaction matrix $J$, and give a polynomial time sampling algorithm when all but $O(1)$ eigenvalues of $J$ lie in an interval of length one, a situation which occurs in many models of interest.
Continual learning: a feature extraction formalization, an efficient algorithm, and fundamental obstructions
When the features are linear, we design an efficient gradient-based algorithm $\mathsf{DPGD}$, that is guaranteed to perform well on the current environment, as well as avoid catastrophic forgetting.
Statistical Efficiency of Score Matching: The View from Isoperimetry
Roughly, we show that the score matching estimator is statistically comparable to the maximum likelihood when the distribution has a small isoperimetric constant.
Pitfalls of Gaussians as a noise distribution in NCE
Noise Contrastive Estimation (NCE) is a popular approach for learning probability density functions parameterized up to a constant of proportionality.
Neural Network Approximations of PDEs Beyond Linearity: A Representational Perspective
We show that if composing a function with Barron norm $b$ with partial derivatives of $L$ produces a function of Barron norm at most $B_L b^p$, the solution to the PDE can be $\epsilon$-approximated in the $L^2$ sense by a function with Barron norm $O\left(\left(dB_L\right)^{\max\{p \log(1/ \epsilon), p^{\log(1/\epsilon)}\}}\right)$.
Understanding Augmentation-based Self-Supervised Representation Learning via RKHS Approximation and Regression
Recent work has built the connection between self-supervised learning and the approximation of the top eigenspace of a graph Laplacian operator, suggesting that learning a linear probe atop such representation can be connected to RKHS regression.
Fit Like You Sample: Sample-Efficient Generalized Score Matching from Fast Mixing Diffusions
Moreover, we show that if the distribution being learned is a finite mixture of Gaussians in $d$ dimensions with a shared covariance, the sample complexity of annealed score matching is polynomial in the ambient dimension, the diameter of the means, and the smallest and largest eigenvalues of the covariance -- obviating the Poincar\'e constant-based lower bounds of the basic score matching loss shown in Koehler et al. 2022.
Outliers with Opposing Signals Have an Outsized Effect on Neural Network Optimization
We identify a new phenomenon in neural network optimization which arises from the interaction of depth and a particular heavy-tailed structure in natural data.
Deep Equilibrium Based Neural Operators for Steady-State PDEs
Motivated by this observation, we propose FNO-DEQ, a deep equilibrium variant of the FNO architecture that directly solves for the solution of a steady-state PDE as the infinite-depth fixed point of an implicit operator layer using a black-box root solver and differentiates analytically through this fixed point resulting in $\mathcal{O}(1)$ training memory.
Transformers are uninterpretable with myopic methods: a case study with bounded Dyck grammars
Interpretability methods aim to understand the algorithm implemented by a trained model (e. g., a Transofmer) by examining various aspects of the model, such as the weight matrices or the attention patterns.
