Search Results for author: Zhichao Xu

Found 26 papers, 8 papers with code

SLOT: Structuring the Output of Large Language Models

no code implementations6 May 2025 Darren Yow-Bang Wang, Zhengyuan Shen, Soumya Smruti Mishra, Zhichao Xu, Yifei Teng, Haibo Ding

Structured outputs are essential for large language models (LLMs) in critical applications like agents and information extraction.

CSPLADE: Learned Sparse Retrieval with Causal Language Models

no code implementations15 Apr 2025 Zhichao Xu, Aosong Feng, Yijun Tian, Haibo Ding, Lin Lee Cheong

In this work, we identify two challenges in training large language models (LLM) for LSR: (1) training instability during the early stage of contrastive training; (2) suboptimal performance due to pre-trained LLM's unidirectional attention.

Information Retrieval Quantization +1

A Survey of Model Architectures in Information Retrieval

no code implementations20 Feb 2025 Zhichao Xu, Fengran Mo, Zhiqi Huang, Crystina Zhang, Puxuan Yu, Bei Wang, Jimmy Lin, Vivek Srikumar

This survey examines the evolution of model architectures in information retrieval (IR), focusing on two key aspects: backbone models for feature extraction and end-to-end system architectures for relevance estimation.

Information Retrieval model +2

MAIN-RAG: Multi-Agent Filtering Retrieval-Augmented Generation

no code implementations31 Dec 2024 Chia-Yuan Chang, Zhimeng Jiang, Vineeth Rakesh, Menghai Pan, Chin-Chia Michael Yeh, Guanchu Wang, Mingzhi Hu, Zhichao Xu, Yan Zheng, Mahashweta Das, Na Zou

Large Language Models (LLMs) are becoming essential tools for various natural language processing tasks but often suffer from generating outdated or incorrect information.

Information Retrieval RAG +2

State Space Models are Strong Text Rerankers

no code implementations18 Dec 2024 Zhichao Xu, Jinghua Yan, Ashim Gupta, Vivek Srikumar

Transformers dominate NLP and IR; but their inference inefficiencies and challenges in extrapolating to longer contexts have sparked interest in alternative model architectures.

Long-Context Understanding Mamba +3

Beyond Perplexity: Multi-dimensional Safety Evaluation of LLM Compression

1 code implementation6 Jul 2024 Zhichao Xu, Ashim Gupta, Tao Li, Oliver Bentham, Vivek Srikumar

To this end, we investigate the impact of model compression along four dimensions: (1) degeneration harm, i. e., bias and toxicity in generation; (2) representational harm, i. e., biases in discriminative tasks; (3) dialect bias; and(4) language modeling and downstream task performance.

Language Modeling Language Modelling +2

RankMamba: Benchmarking Mamba's Document Ranking Performance in the Era of Transformers

1 code implementation27 Mar 2024 Zhichao Xu

In this work, we examine \mamba's efficacy through the lens of a classical IR task -- document ranking.

Benchmarking Document Ranking +3

In-Context Example Ordering Guided by Label Distributions

no code implementations18 Feb 2024 Zhichao Xu, Daniel Cohen, Bei Wang, Vivek Srikumar

Inspired by the idea of learning from label proportions, we propose two principles for in-context example ordering guided by model's probability predictions.

In-Context Learning text-classification +1

Multi-dimensional Evaluation of Empathetic Dialog Responses

no code implementations18 Feb 2024 Zhichao Xu, Jiepu Jiang

Prior efforts to measure conversational empathy mostly focus on expressed communicative intents -- that is, the way empathy is expressed.

Language Modeling Language Modelling

Context-aware Decoding Reduces Hallucination in Query-focused Summarization

1 code implementation21 Dec 2023 Zhichao Xu

Query-focused summarization (QFS) aims to provide a summary of a single document/multi documents that can satisfy the information needs of a given query.

Hallucination Language Modelling +5

FARA: Future-aware Ranking Algorithm for Fairness Optimization

no code implementations26 May 2023 Tao Yang, Zhichao Xu, Zhenduo Wang, Qingyao Ai

However, we find that most existing fair ranking methods adopt greedy algorithms that only optimize rankings for the next immediate session or request.

Exposure Fairness Information Retrieval +1

A Lightweight Constrained Generation Alternative for Query-focused Summarization

1 code implementation23 Apr 2023 Zhichao Xu, Daniel Cohen

Query-focused summarization (QFS) aims to provide a summary of a document that satisfies information need of a given query and is useful in various IR applications, such as abstractive snippet generation.

Language Modeling Language Modelling +3

An In-depth Investigation of User Response Simulation for Conversational Search

no code implementations17 Apr 2023 Zhenduo Wang, Zhichao Xu, Qingyao Ai, Vivek Srikumar

Our goal is to supplement existing work with an insightful hand-analysis of unsolved challenges by the baseline and propose our solutions.

Conversational Search Text Generation +1

Reward-free Policy Imitation Learning for Conversational Search

no code implementations17 Apr 2023 Zhenduo Wang, Zhichao Xu, Qingyao Ai

In this paper, we propose a reward-free conversation policy imitation learning framework, which can train a conversation policy without annotated conversation data or manually designed rewards.

Conversational Search Imitation Learning +1

Counterfactual Editing for Search Result Explanation

no code implementations25 Jan 2023 Zhichao Xu, Hemank Lamba, Qingyao Ai, Joel Tetreault, Alex Jaimes

Next, we formulate a suite of desiderata for counterfactual explanation in SeRE task and corresponding automatic metrics.

counterfactual Counterfactual Explanation +1

Marginal-Certainty-aware Fair Ranking Algorithm

2 code implementations18 Dec 2022 Tao Yang, Zhichao Xu, Zhenduo Wang, Anh Tran, Qingyao Ai

In MCFair, we first develop a ranking objective that includes uncertainty, fairness, and user utility.

Fairness

1st Place Solution of The Robust Vision Challenge 2022 Semantic Segmentation Track

1 code implementation23 Oct 2022 Junfei Xiao, Zhichao Xu, Shiyi Lan, Zhiding Yu, Alan Yuille, Anima Anandkumar

The model is trained on a composite dataset consisting of images from 9 datasets (ADE20K, Cityscapes, Mapillary Vistas, ScanNet, VIPER, WildDash 2, IDD, BDD, and COCO) with a simple dataset balancing strategy.

Segmentation Semantic Segmentation

Reinforcement Learning to Rank with Coarse-grained Labels

no code implementations16 Aug 2022 Zhichao Xu, Anh Tran, Tao Yang, Qingyao Ai

The results on simulated coarse-grained labeled dataset show that while using coarse-grained labels to train an RL model for LTR tasks still can not outperform traditional approaches using fine-grained labels, it still achieve somewhat promising results and is potentially helpful for future research in LTR.

Information Retrieval Learning-To-Rank +4

Learning to Rank Rationales for Explainable Recommendation

1 code implementation10 Jun 2022 Zhichao Xu, Yi Han, Tao Yang, Anh Tran, Qingyao Ai

Seeing this gap, we propose a model named Semantic-Enhanced Bayesian Personalized Explanation Ranking (SE-BPER) to effectively combine the interaction information and semantic information.

Explainable Recommendation Learning-To-Rank +3

Vertical Allocation-based Fair Exposure Amortizing in Ranking

no code implementations6 Apr 2022 Tao Yang, Zhichao Xu, Qingyao Ai

Result ranking often affects consumer satisfaction as well as the amount of exposure each item receives in the ranking services.

Exposure Fairness Recommendation Systems

Understanding the Effectiveness of Reviews in E-commerce Top-N Recommendation

1 code implementation17 Jun 2021 Zhichao Xu, Hansi Zeng, Qingyao Ai

We find that models utilizing only review information can not achieve better performances than vanilla implicit-feedback matrix factorization method.

E-commerce Recommendation with Weighted Expected Utility

no code implementations19 Aug 2020 Zhichao Xu, Yi Han, Yongfeng Zhang, Qingyao Ai

In this paper, we interpret purchase utility as the satisfaction level a consumer gets from a product and propose a recommendation framework using EU to model consumers' behavioral patterns.

Collaborative Filtering Recommendation Systems

Using Sampling Strategy to Assist Consensus Sequence Analysis

no code implementations19 Aug 2020 Zhichao Xu, Shuhong Chen

Consensus Sequences of event logs are often used in process mining to quickly grasp the core sequence of events to be performed in a process, or to represent the backbone of the process for doing other analyses.

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