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Ya-Ping Hsieh

20 accepted papers

2026

A Unified Density Operator View of Flow Control and Merging

ICML 2026poster

Recent progress in large-scale flow and diffusion models raised two fundamental algorithmic challenges: $(i)$ control-based reward adaptation of pre-trained flows, and $(ii)$ integration of multiple models, i.e., flow merging. While current approaches address them separately, we introduce a unifying…

Cited by 0SourceScholar
2026

Flow Expansion via Verifier-Constrained Noised State Space Exploration

ICLR 2026poster

Flow and diffusion models are typically pre-trained on limited available data (e.g., molecular samples), covering only a fraction of the valid design space (e.g., the full molecular space). As a consequence, they tend to generate samples from only a narrow portion of the feasible domain. This is a f…

Cited by 0SourceScholar
2026

When Scores Learn Geometry: Rate Separations under the Manifold Hypothesis

ICLR 2026poster

Score-based methods, such as diffusion models and Bayesian inverse problems, are often interpreted as learning the data distribution in the low-noise limit ($\sigma \to 0$). In this work, we propose an alternative perspective: their success arises from implicitly learning the data manifold rather th…

Cited by 0SourceScholar
2025

Flow Density Control: Generative Optimization Beyond Entropy-Regularized Fine-Tuning

NeurIPS 2025spotlight

Adapting large-scale foundational flow and diffusion generative models to optimize task-specific objectives while preserving prior information is crucial for real-world applications such as molecular design, protein docking, and creative image generation. Existing principled fine-tuning methods aim…

Cited by 0SourceScholar
2025

Provable Maximum Entropy Manifold Exploration via Diffusion Models

ICML 2025poster

Exploration is critical for solving real-world decision-making problems such as scientific discovery, where the objective is to generate truly novel designs rather than mimic existing data distributions. In this work, we address the challenge of leveraging the representational power of generative m…

Cited by 0SourcePDFScholar
2024

Sinkhorn Flow as Mirror Flow: A Continuous-Time Framework for Generalizing the Sinkhorn Algorithm

AISTATS 2024poster

Many problems in machine learning can be formulated as solving entropy-regularized optimal transport on the space of probability measures. The canonical approach involves the Sinkhorn iterates, renowned for their rich mathematical properties. Recently, the Sinkhorn algorithm has been recast within t…

Cited by 10SourcePDFScholar
2023

A Dynamical System View of Langevin-Based Non-Convex Sampling

NeurIPS 2023spotlight

Non-convex sampling is a key challenge in machine learning, central to non-convex optimization in deep learning as well as to approximate probabilistic inference. Despite its significance, theoretically there remain some important challenges: Existing guarantees suffer from the drawback of lacking g…

Cited by 5SourcePDFScholar
2023

Aligned Diffusion Schrödinger Bridges

UAI 2023poster

Diffusion Schrödinger bridges (DSBs) have recently emerged as a powerful framework for recovering stochastic dynamics via their marginal observations at different time points. Despite numerous successful applications, existing algorithms for solving DSBs have so far failed to utilize the structure o…

Cited by 71SourcePDFScholar
2023

Riemannian stochastic optimization methods avoid strict saddle points

NeurIPS 2023poster

Many modern machine learning applications - from online principal component analysis to covariance matrix identification and dictionary learning - can be formulated as minimization problems on Riemannian manifolds, typically solved with a Riemannian stochastic gradient method (or some variant thereo…

Cited by 8SourcePDFScholar
2023

Stochastic Approximation Algorithms for Systems of Interacting Particles

NeurIPS 2023poster

Interacting particle systems have proven highly successful in various machine learning tasks, including approximate Bayesian inference and neural network optimization. However, the analysis of these systems often relies on the simplifying assumption of the \emph{mean-field} limit, where particle num…

Cited by 5SourcePDFScholar
2023

The Schrödinger Bridge between Gaussian Measures has a Closed Form

AISTATS 2023poster

The static optimal transport $(\mathrm{OT})$ problem between Gaussians seeks to recover an optimal map, or more generally a coupling, to morph a Gaussian into another. It has been well studied and applied to a wide variety of tasks. Here we focus on the dynamic formulation of OT, also known as the S…

Cited by 54SourcePDFScholar
2021

The Limits of Min-Max Optimization Algorithms: Convergence to Spurious Non-Critical Sets

ICML 2021oral

Compared to minimization, the min-max optimization in machine learning applications is considerably more convoluted because of the existence of cycles and similar phenomena. Such oscillatory behaviors are well-understood in the convex-concave regime, and many algorithms are known to overcome them. I…

Cited by 112SourcePDFScholar
2020

Conditional gradient methods for stochastically constrained convex minimization

ICML 2020poster

We propose two novel conditional gradient-based methods for solving structured stochastic convex optimization problems with a large number of linear constraints. Instances of this template naturally arise from SDP-relaxations of combinatorial problems, which involve a number of constraints that is p…

Cited by 7SourcePDFScholar
2020

Robust Reinforcement Learning via Adversarial training with Langevin Dynamics

NeurIPS 2020poster

We introduce a \emph{sampling} perspective to tackle the challenging task of training robust Reinforcement Learning (RL) agents. Leveraging the powerful Stochastic Gradient Langevin Dynamics, we present a novel, scalable two-player RL algorithm, which is a sampling variant of the two-player policy g…

Cited by 73SourcePDFScholar
2018

Let’s be Honest: An Optimal No-Regret Framework for Zero-Sum Games

ICML 2018oral

We revisit the problem of solving two-player zero-sum games in the decentralized setting. We propose a simple algorithmic framework that simultaneously achieves the best rates for honest regret as well as adversarial regret, and in addition resolves the open problem of removing the logarithmic terms…

Cited by 27SourcePDFScholar
2016

An Efficient Streaming Algorithm for the Submodular Cover Problem

NeurIPS 2016poster

We initiate the study of the classical Submodular Cover (SC) problem in the data streaming model which we refer to as the Streaming Submodular Cover (SSC). We show that any single pass streaming algorithm using sublinear memory in the size of the stream will fail to provide any non-trivial approxima…

Cited by 27SourcePDFScholar
2016

Frank-Wolfe works for non-Lipschitz continuous gradient objectives: Scalable poisson phase retrieval

ICASSP 2016accepted

We study a phase retrieval problem in the Poisson noise model. Motivated by the PhaseLift approach, we approximate the maximum-likelihood estimator by solving a convex program with a nuclear norm constraint. While the Frank-Wolfe algorithm, together with the Lanczos method, can efficiently deal with…

Cited by 0SourceScholar
2015

Preconditioned Spectral Descent for Deep Learning

NeurIPS 2015poster

Deep learning presents notorious computational challenges. These challenges include, but are not limited to, the non-convexity of learning objectives and estimating the quantities needed for optimization algorithms, such as gradients. While we do not address the non-convexity, we present an optimiza…

Cited by 33SourcePDFScholar