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Kibok Lee

24 accepted papers

2026

AugMask: Score-Based Generative Modeling of Incomplete Tabular Data via Augmentation and Masking

ICML 2026poster

Score-based diffusion models have emerged as prominent deep generative models; however, their application to tabular data remains challenging because their backbones assume fully specified inputs, whereas real-world tabular data often contain missing values. We propose **AugMask**, a plug-and-play t…

Cited by 0SourceScholar
2026

Improving Calibration in Test-Time Prompt Tuning for Vision-Language Models via Data-Free Flatness-Aware Prompt Pretraining

CVPR 2026

Test-time prompt tuning (TPT) has emerged as a promising technique for enhancing the adaptability of vision-language models by optimizing textual prompts using unlabeled test data. However, prior studies have observed that TPT often produces poorly calibrated models, raising concerns about the relia

Cited by 0SourcecodeScholar
2025

A Theoretical Framework for Preventing Class Collapse in Supervised Contrastive Learning

AISTATS 2025poster

Supervised contrastive learning (SupCL) has emerged as a prominent approach in representation learning, leveraging both supervised and self-supervised losses. However, achieving an optimal balance between these losses is challenging; failing to do so can lead to class collapse, reducing discriminati…

Cited by 0SourceScholar
2025

Automated Model Evaluation for Object Detection via Prediction Consistency and Reliability

ICCV 2025poster

Recent advances in computer vision have made training object detectors more efficient and effective; however, assessing their performance in real-world applications still relies on costly manual annotation. To address this limitation, we develop an automated model evaluation (AutoEval) framework for…

2025

On the Similarities of Embeddings in Contrastive Learning

ICML 2025poster

Contrastive learning (CL) operates on a simple yet effective principle: embeddings of positive pairs are pulled together, while those of negative pairs are pushed apart. Although various forms of contrastive loss have been proposed and analyzed from different perspectives, prior works lack a compreh…

2025

Soft Task-Aware Routing of Experts for Equivariant Representation Learning

NeurIPS 2025poster

Equivariant representation learning aims to capture variations induced by input transformations in the representation space, whereas invariant representation learning encodes semantic information by disregarding such transformations. Recent studies have shown that jointly learning both types of repr…

Cited by 0SourcecodeScholar
2025

To Predict or Not to Predict? Proportionally Masked Autoencoders for Tabular Data Imputation

AAAI 2025technical

Masked autoencoders (MAEs) have recently demonstrated effectiveness in tabular data imputation. However, due to the inherent heterogeneity of tabular data, the uniform random masking strategy commonly used in MAEs can disrupt the distribution of missingness, leading to suboptimal performance. To add…

2022

Rethinking Few-Shot Object Detection on a Multi-Domain Benchmark

ECCV 2022poster

"Most existing works on few-shot object detection (FSOD) focus on a setting where both pre-training and few-shot learning datasets are from a similar domain. However, few-shot algorithms are important in multiple domains; hence evaluation needs to reflect the broad applications. We propose a Multi-d…

2021

$i$-Mix: A Domain-Agnostic Strategy for Contrastive Representation Learning

ICLR 2021poster

Contrastive representation learning has shown to be effective to learn representations from unlabeled data. However, much progress has been made in vision domains relying on data augmentations carefully designed using domain knowledge. In this work, we propose i-Mix, a simple yet effective domain-ag…

2021

Improving Transferability of Representations via Augmentation-Aware Self-Supervision

NeurIPS 2021poster

Recent unsupervised representation learning methods have shown to be effective in a range of vision tasks by learning representations invariant to data augmentations such as random cropping and color jittering. However, such invariance could be harmful to downstream tasks if they rely on the charact…

2020

Network Randomization: A Simple Technique for Generalization in Deep Reinforcement Learning

ICLR 2020poster

Deep reinforcement learning (RL) agents often fail to generalize to unseen environments (yet semantically similar to trained agents), particularly when they are trained on high-dimensional state spaces, such as images. In this paper, we propose a simple technique to improve a generalization ability…

Cited by 246SourcecodeScholar
2019

Overcoming Catastrophic Forgetting With Unlabeled Data in the Wild

ICCV 2019poster

Lifelong learning with deep neural networks is well-known to suffer from catastrophic forgetting: the performance on previous tasks drastically degrades when learning a new task. To alleviate this effect, we propose to leverage a large stream of unlabeled data easily obtainable in the wild. In parti…

Cited by 285PDFcodeScholar
2019

Robust Inference via Generative Classifiers for Handling Noisy Labels

ICML 2019oral

Large-scale datasets may contain significant proportions of noisy (incorrect) class labels, and it is well-known that modern deep neural networks (DNNs) poorly generalize from such noisy training datasets. To mitigate the issue, we propose a novel inference method, termed Robust Generative classifie…

2018

A Simple Unified Framework for Detecting Out-of-Distribution Samples and Adversarial Attacks

NeurIPS 2018spotlight

Detecting test samples drawn sufficiently far away from the training distribution statistically or adversarially is a fundamental requirement for deploying a good classifier in many real-world machine learning applications. However, deep neural networks with the softmax classifier are known to produ…

2018

Hierarchical Novelty Detection for Visual Object Recognition

CVPR 2018poster

Deep neural networks have achieved impressive success in large-scale visual object recognition tasks with a predefined set of classes. However, recognizing objects of novel classes unseen during training still remains challenging. The problem of detecting such novel classes has been addressed in the…

Cited by 94SourcePDFScholar
2018

Training Confidence-calibrated Classifiers for Detecting Out-of-Distribution Samples

ICLR 2018poster

The problem of detecting whether a test sample is from in-distribution (i.e., training distribution by a classifier) or out-of-distribution sufficiently different from it arises in many real-world machine learning applications. However, the state-of-art deep neural networks are known to be highly ov…

2016

Augmenting Supervised Neural Networks with Unsupervised Objectives for Large-scale Image Classification

ICML 2016poster

Unsupervised learning and supervised learning are key research topics in deep learning. However, as high-capacity supervised neural networks trained with a large amount of labels have achieved remarkable success in many computer vision tasks, the availability of large-scale labeled images reduced th…

Cited by 177SourcePDFScholar