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Pengtao Xie

42 accepted papers

2026

Models Under SCOPE: Scalable and Controllable Routing via Pre-hoc Reasoning

ICML 2026poster

Model routing chooses which language model to use for each query. By sending easy queries to cheaper models and hard queries to stronger ones, it can significantly reduce inference cost while maintaining high accuracy. However, most existing routers treat this as a fixed choice among a small set of …

Cited by 0SourceScholar
2026

Position: Creating High-Fidelity Synthetic Training Data Should Employ Multi-level Optimization

ICML 2026poster

The reliance of machine learning (ML) models on large-scale, high-quality labeled training data incurs significant challenges in specialized domains where such data is expensive and difficult to obtain. A promising solution is the automatic creation of synthetic training data. However, current appro…

Cited by 0SourceScholar
2026

Position: Deciphering the Functions of DNAs, RNAs, and Proteins Should Consider Multi-Modal Large Language Models

ICML 2026spotlight

Understanding the functions of DNAs, RNAs, and proteins is fundamental to advancing life science research and enabling translational applications such as drug discovery and precision medicine. While deep learning methods have shown promise in biomolecular function prediction, they typically constrai…

Cited by 0SourceScholar
2026

TokenTrace: Multi-Concept Attribution through Watermarked Token Recovery

CVPR 2026

Generative AI models pose a significant challenge to intellectual property (IP), as they can replicate unique artistic styles and concepts without attribution. While watermarking offers a potential solution, existing methods often fail in complex scenarios where multiple concepts (e.g., an object an

Cited by 0SourceScholar
2025

Can Prompts Rewind Time for LLMs? Evaluating the Effectiveness of Prompted Knowledge Cutoffs

EMNLP 2025

Large Language Models (LLMs) are widely used for temporal prediction, but their reliance on pretraining data raises contamination concerns, as accurate predictions on pre-cutoff test data may reflect memorization rather than reasoning, leading to an overestimation of their generalization capability.

2025

Defense against Prompt Injection Attacks via Mixture of Encodings

NAACL 2025short

Large Language Models (LLMs) have emerged as a dominant approach for a wide range of NLP tasks, with their access to external information further enhancing their capabilities. However, this introduces new vulnerabilities, known as prompt injection attacks, where external content embeds malicious ins…

2025

DreamPRM: Domain-reweighted Process Reward Model for Multimodal Reasoning

NeurIPS 2025poster

Reasoning has substantially improved the performance of large language models (LLMs) on complicated tasks. Central to the current reasoning studies, Process Reward Models (PRMs) offer a fine-grained evaluation of intermediate reasoning steps and guide the reasoning process. However, extending PRMs t…

Cited by 0SourceScholar
2025

ExGra-Med: Extended Context Graph Alignment for Medical Vision-Language Models

NeurIPS 2025poster

State-of-the-art medical multi-modal LLMs (med-MLLMs), such as LLaVA-Med and BioMedGPT, primarily depend on scaling model size and data volume, with training driven largely by autoregressive objectives. However, we reveal that this approach can lead to weak vision-language alignment, making these mo…

Cited by 0SourceScholar
2025

Improving the Language Understanding Capabilities of Large Language Models Using Reinforcement Learning

EMNLP 2025

Instruction-fine-tuned large language models (LLMs) under 14B parameters continue to underperform on natural language understanding (NLU) tasks, often trailing smaller models like BERT-base on benchmarks such as GLUE and SuperGLUE. Motivated by the success of reinforcement learning in reasoning task

2024

Accelerating Transformers with Spectrum-Preserving Token Merging

NeurIPS 2024poster

Increasing the throughput of the Transformer architecture, a foundational component used in numerous state-of-the-art models for vision and language tasks (e.g., GPT, LLaVa), is an important problem in machine learning. One recent and effective strategy is to merge token representations within Trans…

2024

AutoLoRA: Automatically Tuning Matrix Ranks in Low-Rank Adaptation Based on Meta Learning

NAACL 2024long

Large-scale pretraining followed by task-specific finetuning has achieved great success in various NLP tasks. Since finetuning all parameters of large pretrained models poses substantial computational and memory challenges, several efficient finetuning methods have been developed. Among them, low-ra…

2024

BLO-SAM: Bi-level Optimization Based Finetuning of the Segment Anything Model for Overfitting-Preventing Semantic Segmentation

ICML 2024poster

The Segment Anything Model (SAM), a foundation model pretrained on millions of images and segmentation masks, has significantly advanced semantic segmentation, a fundamental task in computer vision. Despite its strengths, SAM encounters two major challenges. Firstly, it struggles with segmenting spe…

2024

Generalizable and Stable Finetuning of Pretrained Language Models on Low-Resource Texts

NAACL 2024long

Pretrained Language Models (PLMs) have advanced Natural Language Processing (NLP) tasks significantly, but finetuning PLMs on low-resource datasets poses significant challenges such as instability and overfitting. Previous methods tackle these issues by finetuning a strategically chosen subnetwork o…

2024

Leverage Class-Specific Accuracy to Guide Data Generation for Improving Image Classification

ICML 2024poster

In many image classification applications, the number of labeled training images is limited, which leads to model overfitting. To mitigate the lack of training data, deep generative models have been leveraged to generate synthetic training data. However, existing methods generate data for individual…

Cited by 0SourcePDFScholar
2024

Token-Specific Watermarking with Enhanced Detectability and Semantic Coherence for Large Language Models

ICML 2024poster

Large language models generate high-quality responses with potential misinformation, underscoring the need for regulation by distinguishing AI-generated and human-written texts. Watermarking is pivotal in this context, which involves embedding hidden markers in texts during the LLM inference phase,…

2023

Betty: An Automatic Differentiation Library for Multilevel Optimization

ICLR 2023top-5%

Gradient-based multilevel optimization (MLO) has gained attention as a framework for studying numerous problems, ranging from hyperparameter optimization and meta-learning to neural architecture search and reinforcement learning. However, gradients in MLO, which are obtained by composing best-respon…

2023

Improving Bi-level Optimization Based Methods with Inspiration from Humans' Classroom Study Techniques

ICML 2023poster

In humans' classroom learning, many effective study techniques (e.g., the Feynman technique, peer questioning, etc.) have been developed to improve learning outcomes. We are interested in investigating whether these techniques can inspire the development of ML training strategies to improve bi-level…

Cited by 0SourcePDFScholar
2023

Joint Self-Supervised Image-Volume Representation Learning with Intra-inter Contrastive Clustering

AAAI 2023technical

Collecting large-scale medical datasets with fully annotated samples for training of deep networks is prohibitively expensive, especially for 3D volume data. Recent breakthroughs in self-supervised learning (SSL) offer the ability to overcome the lack of labeled training samples by learning feature…

Cited by 23SourcePDFScholar
2023

LVM-Med: Learning Large-Scale Self-Supervised Vision Models for Medical Imaging via Second-order Graph Matching

NeurIPS 2023poster

Obtaining large pre-trained models that can be fine-tuned to new tasks with limited annotated samples has remained an open challenge for medical imaging data. While pre-trained networks on ImageNet and vision-language foundation models trained on web-scale data are the prevailing approaches, their e…

2023

Learning Compiler Pass Orders using Coreset and Normalized Value Prediction

ICML 2023poster

Finding the optimal pass sequence of compilation can lead to a significant reduction in program size. Prior works on compilation pass ordering have two major drawbacks. They either require an excessive budget (in terms of the number of compilation passes) at compile time or fail to generalize to uns…

2023

Making Scalable Meta Learning Practical

NeurIPS 2023poster

Despite its flexibility to learn diverse inductive biases in machine learning programs, meta learning (i.e.,\ learning to learn) has long been recognized to suffer from poor scalability due to its tremendous compute/memory costs, training instability, and a lack of efficient distributed training sup…

2022

EViT: Expediting Vision Transformers via Token Reorganizations

ICLR 2022spotlight

Vision Transformers (ViTs) take all the image patches as tokens and construct multi-head self-attention (MHSA) among them. Complete leverage of these image tokens brings redundant computations since not all the tokens are attentive in MHSA. Examples include that tokens containing semantically meanin…

2022

Graph Neural Architecture Search Under Distribution Shifts

ICML 2022spotlight

Graph neural architecture search has shown great potentials for automatically designing graph neural network (GNN) architectures for graph classification tasks. However, when there is a distribution shift between training and testing graphs, the existing approaches fail to deal with the problem of a…

Cited by 35SourcePDFScholar
2022

Learning from Mistakes – a Framework for Neural Architecture Search

AAAI 2022technical

Learning from one's mistakes is an effective human learning technique where the learners focus more on the topics where mistakes were made, so as to deepen their understanding. In this paper, we investigate if this human learning strategy can be applied in machine learning. We propose a novel machin…

Cited by 14SourcePDFScholar
2022

MetaWeighting: Learning to Weight Tasks in Multi-Task Learning

ACL 2022findings

Task weighting, which assigns weights on the including tasks during training, significantly matters the performance of Multi-task Learning (MTL); thus, recently, there has been an explosive interest in it. However, existing task weighting methods assign weights only based on the training loss, while…

Cited by 27SourcePDFScholar
2021

Explaining A Black-box By Using A Deep Variational Information Bottleneck Approach

AAAI 2021technical

Interpretable machine learning has gained much attention recently. Briefness and comprehensiveness are necessary in order to provide a large amount of information concisely when explaining a black-box decision system. However, existing interpretable machine learning methods fail to consider briefnes…

2021

On the Generation of Medical Dialogs for COVID-19

ACL 2021short

Under the pandemic of COVID-19, people experiencing COVID19-related symptoms have a pressing need to consult doctors. Because of the shortage of medical professionals, many people cannot receive online consultations timely. To address this problem, we aim to develop a medical dialog system that can…

2021

Towards Visual Question Answering on Pathology Images

ACL 2021short

Pathology imaging is broadly used for identifying the causes and effects of diseases or injuries. Given a pathology image, being able to answer questions about the clinical findings contained in the image is very important for medical decision making. In this paper, we aim to develop a pathological…

2020

Generalized Zero-Shot Text Classification for ICD Coding

IJCAI 2020poster

The International Classification of Diseases (ICD) is a list of classification codes for the diagnoses. Automatic ICD coding is a multi-label text classification problem with noisy clinical document inputs and long-tailed label distribution, making it difficult for fine-grained classification on bot…

2019

Specific and Shared Causal Relation Modeling and Mechanism-Based Clustering

NeurIPS 2019poster

State-of-the-art approaches to causal discovery usually assume a fixed underlying causal model. However, it is often the case that causal models vary across domains or subjects, due to possibly omitted factors that affect the quantitative causal effects. As a typical example, causal connectivity in…

2018

Orthogonality-Promoting Distance Metric Learning: Convex Relaxation and Theoretical Analysis

ICML 2018oral

Distance metric learning (DML), which learns a distance metric from labeled "similar" and "dissimilar" data pairs, is widely utilized. Recently, several works investigate orthogonality-promoting regularization (OPR), which encourages the projection vectors in DML to be close to being orthogonal, to…

Cited by 33SourcePDFScholar
2017

Deep Determinantal Point Process for Large-Scale Multi-Label Classification

ICCV 2017poster

We study large-scale multi-label classification (MLC) on two recently released datasets: Youtube-8M and Open Images that contain millions of data instances and thousands of classes. The unprecedented problem scale poses great challenges for MLC. First, finding out the correct label subset out of exp…

Cited by 33PDFScholar
2017

Learning Latent Space Models with Angular Constraints

ICML 2017poster

The large model capacity of latent space models (LSMs) enables them to achieve great performance on various applications, but meanwhile renders LSMs to be prone to overfitting. Several recent studies investigate a new type of regularization approach, which encourages components in LSMs to be diverse…

Cited by 27SourcePDFScholar