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Hanjun Dai

59 accepted papers

2025

AmorLIP: Efficient Language-Image Pretraining via Amortization

NeurIPS 2025poster

Contrastive Language-Image Pretraining (CLIP) has demonstrated strong zero-shot performance across diverse downstream text-image tasks. Existing CLIP methods typically optimize a contrastive objective using negative samples drawn from each minibatch. To achieve robust representation learning, these…

Cited by 0SourcecodeScholar
2025

Faster WIND: Accelerating Iterative Best-of-$N$ Distillation for LLM Alignment

AISTATS 2025poster

Recent advances in aligning large language models with human preferences have corroborated the growing importance of best-of-$N$ distillation (BOND). However, the iterative BOND algorithm is prohibitively expensive in practice due to the sample and computation inefficiency. This paper addresses the…

Cited by 0SourceScholar
2025

Matryoshka Pilot: Learning to Drive Black-Box LLMs with LLMs

NeurIPS 2025poster

Despite the impressive generative abilities of black-box large language models (LLMs), their inherent opacity hinders further advancements in capabilities such as reasoning, planning, and personalization. Existing works aim to enhance LLM capabilities via domain-specific adaptation, which require a…

Cited by 0SourceScholar
2025

Value-Incentivized Preference Optimization: A Unified Approach to Online and Offline RLHF

ICLR 2025poster

Reinforcement learning from human feedback (RLHF) has demonstrated great promise in aligning large language models (LLMs) with human preference. Depending on the availability of preference data, both online and offline RLHF are active areas of investigation. A key bottleneck is understanding how to…

Cited by 31SourcePDFScholar
2024

Preference Optimization for Molecule Synthesis with Conditional Residual Energy-based Models

ICML 2024oral

Molecule synthesis through machine learning is one of the fundamental problems in drug discovery. Current data-driven strategies employ one-step retrosynthesis models and search algorithms to predict synthetic routes in a top-bottom manner. Despite their effective performance, these strategies face…

2024

UQE: A Query Engine for Unstructured Databases

NeurIPS 2024poster

Analytics on structured data is a mature field with many successful methods. However, most real world data exists in unstructured form, such as images and conversations. We investigate the potential of Large Language Models (LLMs) to enable unstructured data analytics. In particular, we propose a ne…

Cited by 1SourcePDFScholar
2023

Better Zero-Shot Reasoning with Self-Adaptive Prompting

ACL 2023findings

Modern large language models (LLMs) have demonstrated impressive capabilities at sophisticated tasks, often through step-by-step reasoning similar to humans. This is made possible by their strong few- and zero-shot abilities – they can effectively learn from a handful of handcrafted, completed respo…

2023

DISCS: A Benchmark for Discrete Sampling

NeurIPS 2023poster

Sampling in discrete spaces, with critical applications in simulation and optimization, has recently been boosted by significant advances in gradient-based approaches that exploit modern accelerators like GPUs. However, two key challenges are hindering further advancement in research on discrete sam…

2023

Discrete Langevin Samplers via Wasserstein Gradient Flow

AISTATS 2023poster

It is known that gradient based MCMC samplers for continuous spaces, such as Langevin Monte Carlo (LMC), can be derived as particle versions of a gradient flow that minimizes KL divergence on a Wasserstein manifold. The superior efficiency of such samplers has motivated several recent attempts to ge…

2023

LambdaBeam: Neural Program Search with Higher-Order Functions and Lambdas

NeurIPS 2023poster

Search is an important technique in program synthesis that allows for adaptive strategies such as focusing on particular search directions based on execution results. Several prior works have demonstrated that neural models are effective at guiding program synthesis searches. However, a common drawb…

Cited by 11SourcePDFScholar
2023

Learning Universal Policies via Text-Guided Video Generation

NeurIPS 2023spotlight

A goal of artificial intelligence is to construct an agent that can solve a wide variety of tasks. Recent progress in text-guided image synthesis has yielded models with an impressive ability to generate complex novel images, exhibiting combinatorial generalization across domains. Motivated by this…

Cited by 232SourcePDFScholar
2023

Learning to Optimize with Stochastic Dominance Constraints

AISTATS 2023poster

In real-world decision-making, uncertainty is important yet difficult to handle. Stochastic dominance provides a theoretically sound approach to comparing uncertain quantities, but optimization with stochastic dominance constraints is often computationally expensive, which limits practical applicabi…

2023

Let the Flows Tell: Solving Graph Combinatorial Problems with GFlowNets

NeurIPS 2023spotlight

Combinatorial optimization (CO) problems are often NP-hard and thus out of reach for exact algorithms, making them a tempting domain to apply machine learning methods. The highly structured constraints in these problems can hinder either optimization or sampling directly in the solution space. On th…

2023

On Task-personalized Multimodal Few-shot Learning for Visually-rich Document Entity Retrieval

EMNLP 2023long findings

Visually-rich document entity retrieval (VDER), which extracts key information (e.g. date, address) from document images like invoices and receipts, has become an important topic in industrial NLP applications. The emergence of new document types at a constant pace, each with its unique entity types…

Cited by 0SourceScholar
2023

Revisiting Sampling for Combinatorial Optimization

ICML 2023poster

Sampling approaches like Markov chain Monte Carlo were once popular for combinatorial optimization, but the inefficiency of classical methods and the need for problem-specific designs curtailed ongoing development. Recent work has favored data-driven approaches that mitigate the need for hand-craft…

Cited by 18SourcePDFScholar
2023

Universal Self-Adaptive Prompting

EMNLP 2023long main

A hallmark of modern large language models (LLMs) is their impressive general zero-shot and few-shot abilities, often elicited through in-context learning (ICL) via prompting. However, while highly coveted and being the most general, zero-shot performances in LLMs are still typically weaker due to t…

Cited by 0SourceScholar
2023

Video Timeline Modeling For News Story Understanding

NeurIPS 2023spotlight

In this paper, we present a novel problem, namely video timeline modeling. Our objective is to create a video-associated timeline from a set of videos related to a specific topic, thereby facilitating the content and structure understanding of the story being told. This problem has significant poten…

2022

CodeTrek: Flexible Modeling of Code using an Extensible Relational Representation

ICLR 2022poster

Designing a suitable representation for code-reasoning tasks is challenging in aspects such as the kinds of program information to model, how to combine them, and how much context to consider. We propose CodeTrek, a deep learning approach that addresses these challenges by representing codebases as…

2022

CrossBeam: Learning to Search in Bottom-Up Program Synthesis

ICLR 2022poster

Many approaches to program synthesis perform a search within an enormous space of programs to find one that satisfies a given specification. Prior works have used neural models to guide combinatorial search algorithms, but such approaches still explore a huge portion of the search space and quickly…

2022

Marginal Distribution Adaptation for Discrete Sets via Module-Oriented Divergence Minimization

ICML 2022spotlight

Distributions over discrete sets capture the essential statistics including the high-order correlation among elements. Such information provides powerful insight for decision making across various application domains, e.g., product assortment based on product distribution in shopping carts. While de…

Cited by 2SourcePDFScholar
2022

Optimal Scaling for Locally Balanced Proposals in Discrete Spaces

NeurIPS 2022accept

Optimal scaling has been well studied for Metropolis-Hastings (M-H) algorithms in continuous spaces, but a similar understanding has been lacking in discrete spaces. Recently, a family of locally balanced proposals (LBP) for discrete spaces has been proved to be asymptotically optimal, but the quest…

2021

BUSTLE: Bottom-Up Program Synthesis Through Learning-Guided Exploration

ICLR 2021spotlight

Program synthesis is challenging largely because of the difficulty of search in a large space of programs. Human programmers routinely tackle the task of writing complex programs by writing sub-programs and then analyzing their intermediate results to compose them in appropriate ways. Motivated by t…

Cited by 68SourcePDFScholar
2021

Combiner: Full Attention Transformer with Sparse Computation Cost

NeurIPS 2021spotlight

Transformers provide a class of expressive architectures that are extremely effective for sequence modeling. However, the key limitation of transformers is their quadratic memory and time complexity $\mathcal{O}(L^2)$ with respect to the sequence length in attention layers, which restricts applicati…

2021

LEGO: Latent Execution-Guided Reasoning for Multi-Hop Question Answering on Knowledge Graphs

ICML 2021spotlight

Answering complex natural language questions on knowledge graphs (KGQA) is a challenging task. It requires reasoning with the input natural language questions as well as a massive, incomplete heterogeneous KG. Prior methods obtain an abstract structured query graph/tree from the input question and t…

2021

SpreadsheetCoder: Formula Prediction from Semi-structured Context

ICML 2021spotlight

Spreadsheet formula prediction has been an important program synthesis problem with many real-world applications. Previous works typically utilize input-output examples as the specification for spreadsheet formula synthesis, where each input-output pair simulates a separate row in the spreadsheet. H…

2021

Towards understanding retrosynthesis by energy-based models

NeurIPS 2021poster

Retrosynthesis is the process of identifying a set of reactants to synthesize a target molecule. It is of vital importance to material design and drug discovery. Existing machine learning approaches based on language models and graph neural networks have achieved encouraging results. However, the in…

Cited by 47SourcePDFScholar
2020

Differentiable Top-k with Optimal Transport

NeurIPS 2020poster

Finding the k largest or smallest elements from a collection of scores, i.e., top-k operation, is an important model component widely used in information retrieval, machine learning, and data mining. However, if the top-k operation is implemented in an algorithmic way, e.g., using bubble algorithm,…

2020

HOPPITY: LEARNING GRAPH TRANSFORMATIONS TO DETECT AND FIX BUGS IN PROGRAMS

ICLR 2020spotlight

We present a learning-based approach to detect and fix a broad range of bugs in Javascript programs. We frame the problem in terms of learning a sequence of graph transformations: given a buggy program modeled by a graph structure, our model makes a sequence of predictions including the position of…

Cited by 272SourcecodeScholar
2020

Learning Discrete Energy-based Models via Auxiliary-variable Local Exploration

NeurIPS 2020poster

Discrete structures play an important role in applications like program language modeling and software engineering. Current approaches to predicting complex structures typically consider autoregressive models for their tractability, with some sacrifice in flexibility.

2020

Retro*: Learning Retrosynthetic Planning with Neural Guided A* Search

ICML 2020poster

Retrosynthetic planning is a critical task in organic chemistry which identifies a series of reactions that can lead to the synthesis of a target product. The vast number of possible chemical transformations makes the size of the search space very big, and retrosynthetic planning is challenging even…

2020

Scalable Deep Generative Modeling for Sparse Graphs

ICML 2020poster

Learning graph generative models is a challenging task for deep learning and has wide applicability to a range of domains like chemistry, biology and social science. However current deep neural methods suffer from limited scalability: for a graph with n nodes and m edges, existing deep neural method…

2019

CompILE: Compositional Imitation Learning and Execution

ICML 2019oral

We introduce Compositional Imitation Learning and Execution (CompILE): a framework for learning reusable, variable-length segments of hierarchically-structured behavior from demonstration data. CompILE uses a novel unsupervised, fully-differentiable sequence segmentation module to learn latent encod…

2019

Exponential Family Estimation via Adversarial Dynamics Embedding

NeurIPS 2019poster

We present an efficient algorithm for maximum likelihood estimation (MLE) of exponential family models, with a general parametrization of the energy function that includes neural networks. We exploit the primal-dual view of the MLE with a kinetics augmented model to obtain an estimate associated wi…

2019

Kernel Exponential Family Estimation via Doubly Dual Embedding

AISTATS 2019poster

We investigate penalized maximum log-likelihood estimation for exponential family distributions whose natural parameter resides in a reproducing kernel Hilbert space. Key to our approach is a novel technique, doubly dual embedding, that avoids computation of the partition function. This technique al…

2019

Retrosynthesis Prediction with Conditional Graph Logic Network

NeurIPS 2019poster

Retrosynthesis is one of the fundamental problems in organic chemistry. The task is to identify reactants that can be used to synthesize a specified product molecule. Recently, computer-aided retrosynthesis is finding renewed interest from both chemistry and computer science communities. Most existi…

2018

Cooperative neural networks (CoNN): Exploiting prior independence structure for improved classification

NeurIPS 2018poster

We propose a new approach, called cooperative neural networks (CoNN), which use a set of cooperatively trained neural networks to capture latent representations that exploit prior given independence structure. The model is more flexible than traditional graphical models based on exponential family d…

Cited by 14SourcePDFScholar
2018

Coupled Variational Bayes via Optimization Embedding

NeurIPS 2018poster

Variational inference plays a vital role in learning graphical models, especially on large-scale datasets. Much of its success depends on a proper choice of auxiliary distribution class for posterior approximation. However, how to pursue an auxiliary distribution class that achieves both good approx…

2018

Learning Loop Invariants for Program Verification

NeurIPS 2018spotlight

A fundamental problem in program verification concerns inferring loop invariants. The problem is undecidable and even practical instances are challenging. Inspired by how human experts construct loop invariants, we propose a reasoning framework Code2Inv that constructs the solution by multi-step dec…

2018

Learning Steady-States of Iterative Algorithms over Graphs

ICML 2018oral

Many graph analytics problems can be solved via iterative algorithms where the solutions are often characterized by a set of steady-state conditions. Different algorithms respect to different set of fixed point constraints, so instead of using these traditional algorithms, can we learn an algorithm…

Cited by 293SourcePDFScholar
2018

Syntax-Directed Variational Autoencoder for Structured Data

ICLR 2018poster

Deep generative models have been enjoying success in modeling continuous data. However it remains challenging to capture the representations for discrete structures with formal grammars and semantics, e.g., computer programs and molecular structures. How to generate both syntactically and semantical…

2017

Know-Evolve: Deep Temporal Reasoning for Dynamic Knowledge Graphs

ICML 2017poster

The availability of large scale event data with time stamps has given rise to dynamically evolving knowledge graphs that contain temporal information for each edge. Reasoning over time in such dynamic knowledge graphs is not yet well understood. To this end, we present Know-Evolve, a novel deep evol…

2017

Learning Combinatorial Optimization Algorithms over Graphs

NeurIPS 2017spotlight

The design of good heuristics or approximation algorithms for NP-hard combinatorial optimization problems often requires significant specialized knowledge and trial-and-error. Can we automate this challenging, tedious process, and learn the algorithms instead? In many real-world applications, it is…