Search Results for author: Haike Xu

Found 9 papers, 3 papers with code

Statistical-Computational Trade-offs for Density Estimation

no code implementations30 Oct 2024 Anders Aamand, Alexandr Andoni, Justin Y. Chen, Piotr Indyk, Shyam Narayanan, Sandeep Silwal, Haike Xu

In particular, if an algorithm uses $O(n/\log^c k)$ samples for some constant $c>0$ and polynomial space, then the query time of the data structure must be at least $k^{1-O(1)/\log \log k}$, i. e., close to linear in the number of distributions $k$.

Density Estimation

SparseCL: Sparse Contrastive Learning for Contradiction Retrieval

no code implementations15 Jun 2024 Haike Xu, Zongyu Lin, Yizhou Sun, Kai-Wei Chang, Piotr Indyk

Our experiments demonstrate the efficacy of our approach not only in contradiction retrieval with more than 30% accuracy improvements on MSMARCO and HotpotQA across different model architectures but also in applications such as cleaning corrupted corpora to restore high-quality QA retrieval.

Contrastive Learning Fact Checking +2

A Bi-metric Framework for Fast Similarity Search

1 code implementation5 Jun 2024 Haike Xu, Sandeep Silwal, Piotr Indyk

In both cases we show that, as long as the proxy metric used to construct the data structure approximates the ground-truth metric up to a bounded factor, our data structure achieves arbitrarily good approximation guarantees with respect to the ground-truth metric.

MTEB Benchmark Re-Ranking +1

Worst-case Performance of Popular Approximate Nearest Neighbor Search Implementations: Guarantees and Limitations

1 code implementation NeurIPS 2023 Piotr Indyk, Haike Xu

Graph-based approaches to nearest neighbor search are popular and powerful tools for handling large datasets in practice, but they have limited theoretical guarantees.

A Universal Discriminator for Zero-Shot Generalization

1 code implementation15 Nov 2022 Haike Xu, Zongyu Lin, Jing Zhou, Yanan Zheng, Zhilin Yang

In the finetuning setting, our approach also achieves new state-of-the-art results on a wide range of NLP tasks, with only 1/4 parameters of previous methods.

Zero-shot Generalization

Embeddings and labeling schemes for A*

no code implementations19 Nov 2021 Talya Eden, Piotr Indyk, Haike Xu

In particular, we consider heuristics induced by norm embeddings and distance labeling schemes, and provide lower bounds for the tradeoffs between the number of dimensions or bits used to represent each graph node, and the running time of the A* algorithm.

Simple Combinatorial Algorithms for Combinatorial Bandits: Corruptions and Approximations

no code implementations12 Jun 2021 Haike Xu, Jian Li

Our algorithm achieves an (approximation) regret bound of $\tilde{O}\left(d\sqrt{KT}\right)$.

2k

Fine-Grained Gap-Dependent Bounds for Tabular MDPs via Adaptive Multi-Step Bootstrap

no code implementations9 Feb 2021 Haike Xu, Tengyu Ma, Simon S. Du

We further show that for general MDPs, AMB suffers an additional $\frac{|Z_{mul}|}{\Delta_{min}}$ regret, where $Z_{mul}$ is the set of state-action pairs $(s, a)$'s satisfying $a$ is a non-unique optimal action for $s$.

Multi-Armed Bandits

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