Develops MGQDA for multi-group classification with theoretical guarantees and practical applications.
problem Complex multi-group classification problems with nonlinear decision boundaries and group-specific covariance patterns.
method MGQDA, a method based on quadratic discriminant analysis that projects predictors onto a lower-dimensional subspace.
result MGQDA achieves competitive or improved predictive performance compared to existing methods.
The paper proposes a method to improve fairness in classification without using sensitive features directly.
problem Balancing accuracy and fairness in automated decision-making systems.
method Combining Multitask Learning with fairness constraints to train group-specific classifiers.
result The method achieves substantial improvements in both accuracy and fairness on real datasets.
Bayesian data selection framework ensures fairness in machine learning models.
problem High computational costs and limited scalability of fairness-aware methods.
method Bayesian data selection framework using generalized discrepancy measures.
result Consistently outperforms existing methods in fairness and accuracy.
This paper introduces new methods to improve 1-bit matrix completion by considering cluster effects.
problem Improving 1-bit matrix completion for clustered data.
method Group-Specific 1-bit Matrix Completion (GS1MC) and Cluster Developing Matrix Completion (CDMC).
result GS1MC and CDMC outperform existing methods in synthetic and real-world data.
Efficient CVI for NGFA improves GFA inference for large-scale data.
problem Inference limitations in GFA models for large-scale data.
method Collapsed variational inference for nonparametric Bayesian GFA.
result CVI algorithm effectively approximates NGFA posterior in collapsed space.
Bayesian nonparametric approach for clustering non-exchangeable groups.
problem Clustering grouped data with dependencies among groups.
method Graphical Dirichlet process modeling with Markov property.
result Efficient posterior inference algorithm developed.
Due to the escalating growth of big data sets in recent years, new Bayesian Markov chain Monte Carlo (MCMC) parallel computing methods have been developed. These methods partition large data sets by observations into subsets. However, for Bayesian nested hierarchical models, typically only a few parameters are common f…
SharedRep-RLHF learns shared traits for diverse groups, improving fairness and performance.
problem Uniform-reward RLHF fails to capture diverse preferences, leading to unfairness.
method SharedRep-RLHF learns shared traits among various groups, improving fairness and performance.
result SharedRep-RLHF outperforms MaxMin-RLHF by up to 20% in win rate.
CondMTL improves toxicity detection by learning group-specific representations.
problem Algorithmic bias in toxic language detection across demographic groups.
method Conditional Multi-Task Learning (CondMTL) for demographic-specific tasks.
result CondMTL improves predictive recall for minority demographic groups.
New models automate support group formation in online health communities.
problem Challenges in traditional support group formation methods for scalability, static categorization, and insufficient personalization.
method Two novel machine learning models: gDMR and gSTM, integrating user content, demographics, and network data.
result Models outperform baselines in predictive accuracy, semantic coherence, and internal group consistency.
The BNS invariant is applied to Kähler groups in new proofs and results.
problem Understanding properties of Kähler groups through the BNS invariant.
method Applications of the Bieri-Neumann-Strebel invariant on Kähler groups.
result Amenable Kähler groups have an empty complement of the BNS invariant.
We show that a twistor construction of Hitchin and Ward can be adapted to study unitons (harmonic spheres in a unitary group). Specifically, we show that unitons are equivalent to holomorphic bundles with extra structure over a rational ruled surface with energy given by Chern class. This equivalence allows us to confi…
Study examines APOE's impact on AD progression using a novel DEBM approach.
problem Understanding APOE's role in AD progression and developing targeted clinical trials.
method Developed a discriminative event-based model (DEBM) and proposed a stratified approach to improve model accuracy.
result Identified APOE carriers' impact on AD progression timeline, aiding clinical trial selection.
Datasets containing large samples of time-to-event data arising from several small heterogeneous groups are commonly encountered in statistics. This presents problems as they cannot be pooled directly due to their heterogeneity or analyzed individually because of their small sample size. Bayesian nonparametric modellin…
We study inequalities related to the heat kernel for the hypoelliptic sublaplacian on an H-type Lie group. Specifically, we obtain precise pointwise upper and lower bounds on the heat kernel function itself. We then apply these bounds to derive an estimate on the gradient of solutions of the heat equation, which is kno…
Study of CB generating sets for infinite-type surfaces.
problem Understanding CB generating sets for infinite-type surfaces.
method Constructing CB generating sets for specific infinite-type surfaces.
result Examples of surfaces with and without CB generating sets.
We present a Bayesian nonparametric framework for multilevel clustering which utilizes group-level context information to simultaneously discover low-dimensional structures of the group contents and partitions groups into clusters. Using the Dirichlet process as the building block, our model constructs a product base-m…
Word embeddings are a powerful approach for analyzing language, and exponential family embeddings (EFE) extend them to other types of data. Here we develop structured exponential family embeddings (S-EFE), a method for discovering embeddings that vary across related groups of data. We study how the word usage of U.S. C…
Paper tackles fairness in CCA by minimizing correlation disparity error.
problem Fairness issues in CCA.
method Framework to minimize correlation disparity error in CCA.
result Reduces correlation disparity error without sacrificing CCA accuracy.
Group personalization improves FL performance in heterogeneous client data.
problem Mitigating client drift in federated learning with heterogeneous data.
method Fine-tuning a global FL model over homogeneous groups of clients, then personalizing each group's model.
result The proposed method achieves superior personalization performance compared to other FL approaches.
Deep generative models have recently yielded encouraging results in producing subjectively realistic samples of complex data. Far less attention has been paid to making these generative models interpretable. In many scenarios, ranging from scientific applications to finance, the observed variables have a natural groupi…
Extends continuity proof to non-compact manifolds and groups.
problem Automatic continuity for homeomorphism groups of non-compact manifolds.
method Proof extension to non-compact manifolds and groups.
result Homomorphisms from these groups to separable topological groups are continuous.
Study covers of Chamanara surface with large Veech groups.
problem Characterize finite abelian covers with large Veech groups.
method Analyze Veech groups of finite abelian covers of the Chamanara surface.
result Every free group arises as the projective Veech group of a finite-area infinite translation surface.
Paper develops robust methods for panel data with latent groups, improving inference under group separation violations.
problem Inference in latent group panel models under group separation violations.
method Selective conditional inference approach to derive conditional distribution of coefficients given estimated group structure.
result Valid inference under violations of group separation, superior to traditional asymptotic methods.
We explain some interesting relations in the degree three bounded cohomology of surface groups. Specifically, we show that if two faithful Kleinian surface group representations are quasi-isometric, then their bounded fundamental classes are the same in bounded cohomology. This is novel in the setting that one end is d…
Multi-task learning leverages shared information among data sets to improve the learning performance of individual tasks. The paper applies this framework for data where each task is a phase-shifted periodic time series. In particular, we develop a novel Bayesian nonparametric model capturing a mixture of Gaussian proc…
The paper uses machine learning and Lie groups to improve rating transitions and XVA calculations.
problem Improving rating transitions and XVA calculations using machine learning and Lie groups.
method Modeling rating transitions as SDEs on Lie groups, calibrating to historical and market data, applying Girsanov theorem, and using Deep Learning.
result Improves rating transitions and XVA calculations, making the model more robust.
CMDE uses deep learning to estimate causal effects from complex data.
problem Handling complex data structures like images for causal effect estimation.
method Causal Multi-task Deep Ensemble (CMDE) framework.
result CMDE outperforms state-of-the-art methods across various datasets and tasks.
We prove sharp limit theorems on random walks on graphs with values in finite groups. We then apply these results (together with some elementary algebraic geometry, number theory, and representation theory) to finite quotients of lattices in semisimple Lie groups (specifically SL(n,Z) and Sp(2n, Z) to show that a ``ran…
Study finds actuarial unfairness in China's pension system, proposing income-dependent annuitization rules.
problem Actuarial fairness in China's NDC pension system when mortality differs across income groups.
method Developed a mortality-differentiated Lee-Carter framework with group-specific baseline mortality schedules and a common period effect, estimated using national and subgroup data.
result Substantial actuarial unfairness in the current age-only divisor, with a reverse transfer from poorer to richer retirees.
Neural models improve GLMMs for complex data.
problem Nonlinear relationships in grouped data.
method Replaced linear function with neural networks.
result Improved performance on synthetic and real-world data.
Bayesian method improves multivariate periodontal outcome modeling.
problem Modeling periodontal outcomes is challenging and requires consideration of demographic differences.
method Jointly models multivariate outcomes using an online Bayesian transfer learning framework.
result Significant improvement over univariate RECaST method demonstrated.
New method uses latent variables to estimate treatment effects from single-arm trials.
problem Estimating treatment effects from single-arm trials due to lack of external control groups.
method Latent-variable modeling with amortized variational inference for patient matching and direct effect estimation.
result Improved performance in direct treatment effect estimation and effect estimation via patient matching compared to previous methods.
Universal MLPs with a single hidden layer can learn any function.
problem Learning on various data structures like sequences, images, sets, and graphs.
method Using group theory, the paper proves the universality of a broad class of equivariant MLPs with a single hidden layer.
result Having a hidden layer on which the group acts regularly is sufficient for universal equivariance (invariance).
To a Seifert matrix of a knot K one can associate a matrix w(K) with entries in the rational function field, Q(t). The Murasugi, Milnor, and Levine-Tristram knot signatures, all of which provide bounds on the 4-genus of a knot, are determined by w(K). More generally, the minimal rank of a representative of the class re…
Proposes a method to cluster tasks for constructive cooperative multi-tasking.
problem Destructive cooperation in cooperative multi-tasking.
method Semantic clustering followed by end-to-end joint training within clusters.
result Effective mitigation of destructive cooperation and negative transfer.
Estimates nonparametric densities from mixed samples.
problem Unmixing convex combinations of nonparametric densities from observed groups.
method Proposes an estimator using topic modeling and U-statistics.
result Rate-optimal estimator for nonparametric density estimation.
Generalizes results on Bieri-Neumann-Strebel-Renz invariants and tropical varieties.
problem Relationship between Bieri-Neumann-Strebel-Renz invariants and homology jump loci.
method Uses tropical varieties to detect components of homology jump loci and generalizes results to integral coefficients.
result Provides a better upper bound for Bieri-Neumann-Strebel-Renz invariants and classifies Kähler groups.
Method learns shared and specific factors in multi-study gene expression data.
problem Understanding shared and specific factors in high-dimensional multi-study data.
method Nonlinear multi-study factor model with sparse variational autoencoder.
result Method recovers meaningful shared and specific factors in platelet gene expression data.
EbC learns equivariant embeddings from unlabeled group actions.
problem Learning equivariant embeddings from unlabeled group actions.
method Equivariance by Contrast (EbC) method to learn equivariant embeddings from observation pairs (y,g⋅y). result High-fidelity equivariance in latent space for diverse groups.
Let G be a complex simple direct limit group, specifically SL(∞;C), SO(∞;C) or Sp(∞;C). Let F be a (generalized) flag in C∞. If G is SO(∞;C) or Sp(∞;C) we suppose further that F is isotropic. Let…
Derivative map for disk diffeomorphisms induces nontrivial homotopy groups.
problem Proving nontriviality of homomorphisms induced by derivative maps.
method Combining recent results on homotopy spheres, plumbing approach, and explicit constructions.
result Non-zero homomorphism between specific homotopy groups.
A method for fair representation learning through bi-level optimization and implicit differentiation.
problem Ensuring fair predictors invariant across sub-groups.
method Bi-level optimization with inner-loop for invariant predictors, implicit path alignment for efficiency.
result Consistently better trade-off in prediction performance and fairness measurement.
As data collections become larger, exploratory regression analysis becomes more important but more challenging. When observations are hierarchically clustered the problem is even more challenging because model selection with mixed effect models can produce misleading results when nonlinear effects are not included into…
Method estimates shared and study-specific factors for multi-study data.
problem Covariance estimation for multi-study data with shared and study-specific components.
method Spectral decomposition for latent factors, surrogate Bayesian regressions for loadings and variances.
result Strong frequentist guarantees and superior performance in simulations and real data.
New framework tackles stochastic latent subgroup heterogeneity in online decision-making.
problem Stochastic latent heterogeneity in online decision-making where individual responses vary with unobserved subgroups.
method Latent heterogeneous bandit framework using EM-greedy algorithm to learn subgroup probabilities and reward parameters.
result Achieves optimal estimation and classification guarantees, revealing a fundamental stochastic barrier in online decision-making.
A novel validation method improves feature importance analysis in subject-specific ML models.
problem Limited effectiveness of general ML models trained on large datasets for individual patient outcomes.
method A novel validation approach using a general ML model with repeated trials and random seed variation.
result Consistent identification of key features at the subject level and improved group-level feature importance analysis.
New framework reduces strategic manipulation cost for minority groups in fair classification.
problem Strategic manipulation disparities in fair classification.
method Constrained optimization framework that constructs classifiers to reduce strategic manipulation cost for minority groups.
result Empirically, the approach reduces strategic manipulation cost for minority groups over multiple real-world datasets.