Search Results for author: Thomas C. M. Lee

Found 12 papers, 3 papers with code

Efficient Frameworks for Generalized Low-Rank Matrix Bandit Problems

no code implementations14 Jan 2024 Yue Kang, Cho-Jui Hsieh, Thomas C. M. Lee

In the stochastic contextual low-rank matrix bandit problem, the expected reward of an action is given by the inner product between the action's feature matrix and some fixed, but initially unknown $d_1$ by $d_2$ matrix $\Theta^*$ with rank $r \ll \{d_1, d_2\}$, and an agent sequentially takes actions based on past experience to maximize the cumulative reward.

Online Continuous Hyperparameter Optimization for Generalized Linear Contextual Bandits

no code implementations18 Feb 2023 Yue Kang, Cho-Jui Hsieh, Thomas C. M. Lee

In stochastic contextual bandits, an agent sequentially makes actions from a time-dependent action set based on past experience to minimize the cumulative regret.

Hyperparameter Optimization Multi-Armed Bandits +1

Extending the Use of MDL for High-Dimensional Problems: Variable Selection, Robust Fitting, and Additive Modeling

no code implementations26 Jan 2022 Zhenyu Wei, Raymond K. W. Wong, Thomas C. M. Lee

In the signal processing and statistics literature, the minimum description length (MDL) principle is a popular tool for choosing model complexity.

Additive models Denoising +2

A Review of Adversarial Attack and Defense for Classification Methods

1 code implementation18 Nov 2021 Yao Li, Minhao Cheng, Cho-Jui Hsieh, Thomas C. M. Lee

Despite the efficiency and scalability of machine learning systems, recent studies have demonstrated that many classification methods, especially deep neural networks (DNNs), are vulnerable to adversarial examples; i. e., examples that are carefully crafted to fool a well-trained classification model while being indistinguishable from natural data to human.

Adversarial Attack Classification

Syndicated Bandits: A Framework for Auto Tuning Hyper-parameters in Contextual Bandit Algorithms

no code implementations5 Jun 2021 Qin Ding, Yue Kang, Yi-Wei Liu, Thomas C. M. Lee, Cho-Jui Hsieh, James Sharpnack

To tackle this problem, we first propose a two-layer bandit structure for auto tuning the exploration parameter and further generalize it to the Syndicated Bandits framework which can learn multiple hyper-parameters dynamically in contextual bandit environment.

Recommendation Systems

Adversarial Examples Detection with Bayesian Neural Network

1 code implementation18 May 2021 Yao Li, Tongyi Tang, Cho-Jui Hsieh, Thomas C. M. Lee

In this paper, we propose a new framework to detect adversarial examples motivated by the observations that random components can improve the smoothness of predictors and make it easier to simulate the output distribution of a deep neural network.

Uncertainty Quantification in Ensembles of Honest Regression Trees using Generalized Fiducial Inference

no code implementations14 Nov 2019 Suofei Wu, Jan Hannig, Thomas C. M. Lee

The main contribution is a new method that quantifies the uncertainties of the estimates and predictions produced by honest random forests.

Prediction Intervals regression +1

Measuring the Algorithmic Convergence of Randomized Ensembles: The Regression Setting

no code implementations4 Aug 2019 Miles E. Lopes, Suofei Wu, Thomas C. M. Lee

When randomized ensemble methods such as bagging and random forests are implemented, a basic question arises: Is the ensemble large enough?

General Classification regression +1

Block-wise Partitioning for Extreme Multi-label Classification

no code implementations4 Nov 2018 Yuefeng Liang, Cho-Jui Hsieh, Thomas C. M. Lee

Extreme multi-label classification aims to learn a classifier that annotates an instance with a relevant subset of labels from an extremely large label set.

Classification Extreme Multi-Label Classification +1

Detecting Abrupt Changes in the Spectra of High-Energy Astrophysical Sources

1 code implementation28 Aug 2015 Raymond K. W. Wong, Vinay L. Kashyap, Thomas C. M. Lee, David A. van Dyk

We embed change points into a marked Poisson process, where photon wavelengths are regarded as marks and both the Poisson intensity parameter and the distribution of the marks are allowed to change.

Applications Instrumentation and Methods for Astrophysics

Matrix Completion with Noisy Entries and Outliers

no code implementations1 Mar 2015 Raymond K. W. Wong, Thomas C. M. Lee

This paper considers the problem of matrix completion when the observed entries are noisy and contain outliers.

Image Inpainting Matrix Completion

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