Search Results for author: Nan Jiang

Found 100 papers, 29 papers with code

Doubly Robust Off-policy Value Evaluation for Reinforcement Learning

2 code implementations11 Nov 2015 Nan Jiang, Lihong Li

We study the problem of off-policy value evaluation in reinforcement learning (RL), where one aims to estimate the value of a new policy based on data collected by a different policy.

Decision Making reinforcement-learning +1

Scale Match for Tiny Person Detection

2 code implementations23 Dec 2019 Xuehui Yu, Yuqi Gong, Nan Jiang, Qixiang Ye, Zhenjun Han

In this paper, we introduce a new benchmark, referred to as TinyPerson, opening up a promising directionfor tiny object detection in a long distance and with mas-sive backgrounds.

Human Detection Object +2

The 1st Tiny Object Detection Challenge:Methods and Results

1 code implementation16 Sep 2020 Xuehui Yu, Zhenjun Han, Yuqi Gong, Nan Jiang, Jian Zhao, Qixiang Ye, Jie Chen, Yuan Feng, Bin Zhang, Xiaodi Wang, Ying Xin, Jingwei Liu, Mingyuan Mao, Sheng Xu, Baochang Zhang, Shumin Han, Cheng Gao, Wei Tang, Lizuo Jin, Mingbo Hong, Yuchao Yang, Shuiwang Li, Huan Luo, Qijun Zhao, Humphrey Shi

The 1st Tiny Object Detection (TOD) Challenge aims to encourage research in developing novel and accurate methods for tiny object detection in images which have wide views, with a current focus on tiny person detection.

Human Detection Object +2

Anti-UAV: A Large Multi-Modal Benchmark for UAV Tracking

1 code implementation21 Jan 2021 Nan Jiang, Kuiran Wang, Xiaoke Peng, Xuehui Yu, Qiang Wang, Junliang Xing, Guorong Li, Jian Zhao, Guodong Guo, Zhenjun Han

The releasing of such a large-scale dataset could be a useful initial step in research of tracking UAVs.

Adversarially Trained Actor Critic for Offline Reinforcement Learning

3 code implementations5 Feb 2022 Ching-An Cheng, Tengyang Xie, Nan Jiang, Alekh Agarwal

We propose Adversarially Trained Actor Critic (ATAC), a new model-free algorithm for offline reinforcement learning (RL) under insufficient data coverage, based on the concept of relative pessimism.

Continuous Control D4RL +3

Quantifying Spatial Homogeneity of Urban Road Networks via Graph Neural Networks

1 code implementation1 Jan 2021 Jiawei Xue, Nan Jiang, Senwei Liang, Qiyuan Pang, Takahiro Yabe, Satish V. Ukkusuri, Jianzhu Ma

We apply the method to 11, 790 urban road networks across 30 cities worldwide to measure the spatial homogeneity of road networks within each city and across different cities.

Full-Body Articulated Human-Object Interaction

1 code implementation ICCV 2023 Nan Jiang, Tengyu Liu, Zhexuan Cao, Jieming Cui, Zhiyuan Zhang, Yixin Chen, He Wang, Yixin Zhu, Siyuan Huang

By learning the geometrical relationships in HOI, we devise the very first model that leverage human pose estimation to tackle the estimation of articulated object poses and shapes during whole-body interactions.

Action Recognition Human-Object Interaction Detection +3

Empirical Study of Off-Policy Policy Evaluation for Reinforcement Learning

3 code implementations15 Nov 2019 Cameron Voloshin, Hoang M. Le, Nan Jiang, Yisong Yue

We offer an experimental benchmark and empirical study for off-policy policy evaluation (OPE) in reinforcement learning, which is a key problem in many safety critical applications.

Benchmarking Experimental Design +2

RouterBench: A Benchmark for Multi-LLM Routing System

1 code implementation18 Mar 2024 Qitian Jason Hu, Jacob Bieker, Xiuyu Li, Nan Jiang, Benjamin Keigwin, Gaurav Ranganath, Kurt Keutzer, Shriyash Kaustubh Upadhyay

To bridge this gap, we present RouterBench, a novel evaluation framework designed to systematically assess the efficacy of LLM routing systems, along with a comprehensive dataset comprising over 405k inference outcomes from representative LLMs to support the development of routing strategies.

CURE: Code-Aware Neural Machine Translation for Automatic Program Repair

1 code implementation26 Feb 2021 Nan Jiang, Thibaud Lutellier, Lin Tan

Finally, CURE uses a subword tokenization technique to generate a smaller search space that contains more correct fixes.

Machine Translation NMT +2

Provably efficient RL with Rich Observations via Latent State Decoding

1 code implementation25 Jan 2019 Simon S. Du, Akshay Krishnamurthy, Nan Jiang, Alekh Agarwal, Miroslav Dudík, John Langford

We study the exploration problem in episodic MDPs with rich observations generated from a small number of latent states.

Clustering Q-Learning +1

KNOD: Domain Knowledge Distilled Tree Decoder for Automated Program Repair

1 code implementation3 Feb 2023 Nan Jiang, Thibaud Lutellier, Yiling Lou, Lin Tan, Dan Goldwasser, Xiangyu Zhang

KNOD has two major novelties, including (1) a novel three-stage tree decoder, which directly generates Abstract Syntax Trees of patched code according to the inherent tree structure, and (2) a novel domain-rule distillation, which leverages syntactic and semantic rules and teacher-student distributions to explicitly inject the domain knowledge into the decoding procedure during both the training and inference phases.

Program Repair

How Effective Are Neural Networks for Fixing Security Vulnerabilities

1 code implementation29 May 2023 Yi Wu, Nan Jiang, Hung Viet Pham, Thibaud Lutellier, Jordan Davis, Lin Tan, Petr Babkin, Sameena Shah

The results call for innovations to enhance automated Java vulnerability repair such as creating larger vulnerability repair training data, tuning LLMs with such data, and applying code simplification transformation to facilitate vulnerability repair.

Code Completion Program Repair

When Counterpoint Meets Chinese Folk Melodies

1 code implementation NeurIPS 2020 Nan Jiang, Sheng Jin, Zhiyao Duan, ChangShui Zhang

An interaction reward model is trained on the duets formed from outer parts of Bach chorales to model counterpoint interaction, while a style reward model is trained on monophonic melodies of Chinese folk songs to model melodic patterns.

Batch Value-function Approximation with Only Realizability

1 code implementation11 Aug 2020 Tengyang Xie, Nan Jiang

We make progress in a long-standing problem of batch reinforcement learning (RL): learning $Q^\star$ from an exploratory and polynomial-sized dataset, using a realizable and otherwise arbitrary function class.

Model Selection Reinforcement Learning (RL)

Towards Hyperparameter-free Policy Selection for Offline Reinforcement Learning

1 code implementation NeurIPS 2021 Siyuan Zhang, Nan Jiang

How to select between policies and value functions produced by different training algorithms in offline reinforcement learning (RL) -- which is crucial for hyperpa-rameter tuning -- is an important open question.

Off-policy evaluation Open-Ended Question Answering +1

Future-Dependent Value-Based Off-Policy Evaluation in POMDPs

1 code implementation NeurIPS 2023 Masatoshi Uehara, Haruka Kiyohara, Andrew Bennett, Victor Chernozhukov, Nan Jiang, Nathan Kallus, Chengchun Shi, Wen Sun

Finally, we extend our methods to learning of dynamics and establish the connection between our approach and the well-known spectral learning methods in POMDPs.

Off-policy evaluation

A Minimax Learning Approach to Off-Policy Evaluation in Confounded Partially Observable Markov Decision Processes

1 code implementation12 Nov 2021 Chengchun Shi, Masatoshi Uehara, Jiawei Huang, Nan Jiang

In this work, we first propose novel identification methods for OPE in POMDPs with latent confounders, by introducing bridge functions that link the target policy's value and the observed data distribution.

Off-policy evaluation

From Importance Sampling to Doubly Robust Policy Gradient

1 code implementation ICML 2020 Jiawei Huang, Nan Jiang

We show that on-policy policy gradient (PG) and its variance reduction variants can be derived by taking finite difference of function evaluations supplied by estimators from the importance sampling (IS) family for off-policy evaluation (OPE).

Off-policy evaluation

Learning Markov Random Fields for Combinatorial Structures via Sampling through Lovász Local Lemma

1 code implementation1 Dec 2022 Nan Jiang, Yi Gu, Yexiang Xue

Contrastive divergence is then applied to separate these samples from those in the training set.

LEMMA valid

Ultrasonic Image's Annotation Removal: A Self-supervised Noise2Noise Approach

1 code implementation9 Jul 2023 Yuanheng Zhang, Nan Jiang, Zhaoheng Xie, Junying Cao, Yueyang Teng

Accurately annotated ultrasonic images are vital components of a high-quality medical report.

Denoising

Is attention required for ICL? Exploring the Relationship Between Model Architecture and In-Context Learning Ability

1 code implementation12 Oct 2023 Ivan Lee, Nan Jiang, Taylor Berg-Kirkpatrick

We also measure each architecture's predisposition towards in-context learning when presented with the option to memorize rather than leverage in-context examples.

Causal Language Modeling In-Context Learning +1

Tiered Reinforcement Learning: Pessimism in the Face of Uncertainty and Constant Regret

1 code implementation25 May 2022 Jiawei Huang, Li Zhao, Tao Qin, Wei Chen, Nan Jiang, Tie-Yan Liu

We propose a new learning framework that captures the tiered structure of many real-world user-interaction applications, where the users can be divided into two groups based on their different tolerance on exploration risks and should be treated separately.

reinforcement-learning Reinforcement Learning (RL)

Explaining RL Decisions with Trajectories

1 code implementation6 May 2023 Shripad Vilasrao Deshmukh, Arpan Dasgupta, Balaji Krishnamurthy, Nan Jiang, Chirag Agarwal, Georgios Theocharous, Jayakumar Subramanian

To do so, we encode trajectories in offline training data individually as well as collectively (encoding a set of trajectories).

Attribute Continuous Control +3

Image Classification Based on Quantum KNN Algorithm

no code implementations16 May 2018 Yijie Dang, Nan Jiang, Hao Hu, Zhuoxiao Ji, Wenyin Zhang

However, the usually used classification method --- the K Nearest-Neighbor algorithm has high complexity, because its two main processes: similarity computing and searching are time-consuming.

Classification General Classification +1

Optimizing Recurrent Neural Networks Architectures under Time Constraints

no code implementations29 Aug 2016 Junqi Jin, Ziang Yan, Kun fu, Nan Jiang, Chang-Shui Zhang

A greedy algorithm with bounds is suggested to solve the transformed problem.

Neural Network Architecture Optimization through Submodularity and Supermodularity

no code implementations1 Sep 2016 Junqi Jin, Ziang Yan, Kun fu, Nan Jiang, Chang-Shui Zhang

Deep learning models' architectures, including depth and width, are key factors influencing models' performance, such as test accuracy and computation time.

Markov Decision Processes with Continuous Side Information

no code implementations15 Nov 2017 Aditya Modi, Nan Jiang, Satinder Singh, Ambuj Tewari

Because our lower bound has an exponential dependence on the dimension, we consider a tractable linear setting where the context is used to create linear combinations of a finite set of MDPs.

PAC learning Reinforcement Learning (RL)

Repeated Inverse Reinforcement Learning

no code implementations NeurIPS 2017 Kareem Amin, Nan Jiang, Satinder Singh

We introduce a novel repeated Inverse Reinforcement Learning problem: the agent has to act on behalf of a human in a sequence of tasks and wishes to minimize the number of tasks that it surprises the human by acting suboptimally with respect to how the human would have acted.

Imitation Learning reinforcement-learning +1

Contextual Decision Processes with Low Bellman Rank are PAC-Learnable

no code implementations ICML 2017 Nan Jiang, Akshay Krishnamurthy, Alekh Agarwal, John Langford, Robert E. Schapire

Our first contribution is a complexity measure, the Bellman rank, that we show enables tractable learning of near-optimal behavior in these processes and is naturally small for many well-studied reinforcement learning settings.

Efficient Exploration reinforcement-learning +1

Word Embedding based Correlation Model for Question/Answer Matching

no code implementations15 Nov 2015 Yikang Shen, Wenge Rong, Nan Jiang, Baolin Peng, Jie Tang, Zhang Xiong

With the development of community based question answering (Q&A) services, a large scale of Q&A archives have been accumulated and are an important information and knowledge resource on the web.

Question Answering Translation

Model-based RL in Contextual Decision Processes: PAC bounds and Exponential Improvements over Model-free Approaches

no code implementations21 Nov 2018 Wen Sun, Nan Jiang, Akshay Krishnamurthy, Alekh Agarwal, John Langford

We study the sample complexity of model-based reinforcement learning (henceforth RL) in general contextual decision processes that require strategic exploration to find a near-optimal policy.

Model-based Reinforcement Learning

LSDSCC: a Large Scale Domain-Specific Conversational Corpus for Response Generation with Diversity Oriented Evaluation Metrics

no code implementations NAACL 2018 Zhen Xu, Nan Jiang, Bingquan Liu, Wenge Rong, Bowen Wu, Baoxun Wang, Zhuoran Wang, Xiaolong Wang

The experimental results have shown that our proposed corpus can be taken as a new benchmark dataset for the NRG task, and the presented metrics are promising to guide the optimization of NRG models by quantifying the diversity of the generated responses reasonably.

Machine Translation Response Generation

Completing State Representations using Spectral Learning

no code implementations NeurIPS 2018 Nan Jiang, Alex Kulesza, Satinder Singh

A central problem in dynamical system modeling is state discovery—that is, finding a compact summary of the past that captures the information needed to predict the future.

Unifying Spatial and Attribute Selection for Distracter-Resilient Tracking

no code implementations CVPR 2014 Nan Jiang, Ying Wu

This paper presents a novel method to jointly determine the best spatial location and the optimal metric.

Attribute

Information-Theoretic Considerations in Batch Reinforcement Learning

no code implementations1 May 2019 Jinglin Chen, Nan Jiang

Value-function approximation methods that operate in batch mode have foundational importance to reinforcement learning (RL).

reinforcement-learning Reinforcement Learning (RL)

Provably Efficient Q-Learning with Low Switching Cost

no code implementations NeurIPS 2019 Yu Bai, Tengyang Xie, Nan Jiang, Yu-Xiang Wang

We take initial steps in studying PAC-MDP algorithms with limited adaptivity, that is, algorithms that change its exploration policy as infrequently as possible during regret minimization.

Q-Learning

On Value Functions and the Agent-Environment Boundary

no code implementations30 May 2019 Nan Jiang

When function approximation is deployed in reinforcement learning (RL), the same problem may be formulated in different ways, often by treating a pre-processing step as a part of the environment or as part of the agent.

Imitation Learning reinforcement-learning +1

Sample Complexity of Reinforcement Learning using Linearly Combined Model Ensembles

no code implementations23 Oct 2019 Aditya Modi, Nan Jiang, Ambuj Tewari, Satinder Singh

As an extension, we also consider the more challenging problem of model selection, where the state features are unknown and can be chosen from a large candidate set.

Model Selection reinforcement-learning +1

Minimax Weight and Q-Function Learning for Off-Policy Evaluation

no code implementations ICML 2020 Masatoshi Uehara, Jiawei Huang, Nan Jiang

We provide theoretical investigations into off-policy evaluation in reinforcement learning using function approximators for (marginalized) importance weights and value functions.

Off-policy evaluation

Quantum Communication between Multiplexed Atomic Quantum Memories

no code implementations5 Sep 2019 Chang Li, Nan Jiang, Yukai Wu, Wei Chang, Yunfei Pu, Sheng Zhang, Lu-Ming Duan

The use of multiplexed atomic quantum memories (MAQM) can significantly enhance the efficiency to establish entanglement in a quantum network.

Quantum Physics

Minimax Value Interval for Off-Policy Evaluation and Policy Optimization

no code implementations NeurIPS 2020 Nan Jiang, Jiawei Huang

By slightly altering the derivation of previous methods (one from each style; Uehara et al., 2020), we unify them into a single value interval that comes with a special type of double robustness: when either the value-function or the importance-weight class is well specified, the interval is valid and its length quantifies the misspecification of the other class.

Efficient Exploration Off-policy evaluation +1

RL-Duet: Online Music Accompaniment Generation Using Deep Reinforcement Learning

no code implementations8 Feb 2020 Nan Jiang, Sheng Jin, Zhiyao Duan, Chang-Shui Zhang

We cast this as a reinforcement learning problem, where the generation agent learns a policy to generate a musical note (action) based on previously generated context (state).

Music Generation reinforcement-learning +1

Q* Approximation Schemes for Batch Reinforcement Learning: A Theoretical Comparison

no code implementations9 Mar 2020 Tengyang Xie, Nan Jiang

We prove performance guarantees of two algorithms for approximating $Q^\star$ in batch reinforcement learning.

reinforcement-learning Reinforcement Learning (RL)

A Question Type Driven and Copy Loss Enhanced Frameworkfor Answer-Agnostic Neural Question Generation

no code implementations WS 2020 Xiuyu Wu, Nan Jiang, Yunfang Wu

The answer-agnostic question generation is a significant and challenging task, which aims to automatically generate questions for a given sentence but without an answer.

Question Generation Question-Generation +2

A Variant of the Wang-Foster-Kakade Lower Bound for the Discounted Setting

no code implementations2 Nov 2020 Philip Amortila, Nan Jiang, Tengyang Xie

Recently, Wang et al. (2020) showed a highly intriguing hardness result for batch reinforcement learning (RL) with linearly realizable value function and good feature coverage in the finite-horizon case.

reinforcement-learning Reinforcement Learning (RL)

Analysis of Random Access in NB-IoT Networks with Three Coverage Enhancement Groups: A Stochastic Geometry Approach

no code implementations14 Sep 2020 Yan Liu, Yansha Deng, Nan Jiang, Maged Elkashlan, Arumugam Nallanathan

NarrowBand-Internet of Things (NB-IoT) is a new 3GPP radio access technology designed to provide better coverage for Low Power Wide Area (LPWA) networks.

Experimental demonstration of memory-enhanced scaling for entanglement connection of quantum repeater segments

no code implementations21 Jan 2021 Yunfei Pu, Sheng Zhang, Yukai Wu, Nan Jiang, Wei Chang, Chang Li, Luming Duan

The experimental realization of entanglement connection of two quantum repeater segments with an efficient memory-enhanced scaling demonstrates a key advantage of the quantum repeater protocol, which makes a cornerstone towards future large-scale quantum networks.

Quantum Physics

On Query-efficient Planning in MDPs under Linear Realizability of the Optimal State-value Function

no code implementations3 Feb 2021 Gellért Weisz, Philip Amortila, Barnabás Janzer, Yasin Abbasi-Yadkori, Nan Jiang, Csaba Szepesvári

We consider local planning in fixed-horizon MDPs with a generative model under the assumption that the optimal value function lies close to the span of a feature map.

Open-Ended Question Answering

Finite Sample Analysis of Minimax Offline Reinforcement Learning: Completeness, Fast Rates and First-Order Efficiency

no code implementations5 Feb 2021 Masatoshi Uehara, Masaaki Imaizumi, Nan Jiang, Nathan Kallus, Wen Sun, Tengyang Xie

We offer a theoretical characterization of off-policy evaluation (OPE) in reinforcement learning using function approximation for marginal importance weights and $q$-functions when these are estimated using recent minimax methods.

Off-policy evaluation reinforcement-learning

SM+: Refined Scale Match for Tiny Person Detection

no code implementations6 Feb 2021 Nan Jiang, Xuehui Yu, Xiaoke Peng, Yuqi Gong, Zhenjun Han

Detecting tiny objects ( e. g., less than 20 x 20 pixels) in large-scale images is an important yet open problem.

Human Detection

Minimax Model Learning

no code implementations2 Mar 2021 Cameron Voloshin, Nan Jiang, Yisong Yue

We present a novel off-policy loss function for learning a transition model in model-based reinforcement learning.

Model-based Reinforcement Learning Off-policy evaluation +1

On the Convergence Rate of Off-Policy Policy Optimization Methods with Density-Ratio Correction

no code implementations2 Jun 2021 Jiawei Huang, Nan Jiang

In this paper, we study the convergence properties of off-policy policy improvement algorithms with state-action density ratio correction under function approximation setting, where the objective function is formulated as a max-max-min optimization problem.

Policy Finetuning: Bridging Sample-Efficient Offline and Online Reinforcement Learning

no code implementations NeurIPS 2021 Tengyang Xie, Nan Jiang, Huan Wang, Caiming Xiong, Yu Bai

This offline result is the first that matches the sample complexity lower bound in this setting, and resolves a recent open question in offline RL.

Offline RL Open-Ended Question Answering +2

Bellman-consistent Pessimism for Offline Reinforcement Learning

no code implementations NeurIPS 2021 Tengyang Xie, Ching-An Cheng, Nan Jiang, Paul Mineiro, Alekh Agarwal

The use of pessimism, when reasoning about datasets lacking exhaustive exploration has recently gained prominence in offline reinforcement learning.

reinforcement-learning Reinforcement Learning (RL)

A Spectral Approach to Off-Policy Evaluation for POMDPs

no code implementations22 Sep 2021 Yash Nair, Nan Jiang

We consider off-policy evaluation (OPE) in Partially Observable Markov Decision Processes, where the evaluation policy depends only on observable variables but the behavior policy depends on latent states (Tennenholtz et al. (2020a)).

Causal Identification Off-policy evaluation

A Fast Randomized Algorithm for Massive Text Normalization

no code implementations6 Oct 2021 Nan Jiang, Chen Luo, Vihan Lakshman, Yesh Dattatreya, Yexiang Xue

In addition, FLAN does not require any annotated data or supervised learning.

Offline Reinforcement Learning with Realizability and Single-policy Concentrability

no code implementations9 Feb 2022 Wenhao Zhan, Baihe Huang, Audrey Huang, Nan Jiang, Jason D. Lee

Sample-efficiency guarantees for offline reinforcement learning (RL) often rely on strong assumptions on both the function classes (e. g., Bellman-completeness) and the data coverage (e. g., all-policy concentrability).

Offline RL reinforcement-learning +1

VRConvMF: Visual Recurrent Convolutional Matrix Factorization for Movie Recommendation

no code implementations16 Feb 2022 Zhu Wang, Honglong Chen, Zhe Li, Kai Lin, Nan Jiang, Feng Xia

Fortunately, context-aware recommender systems can alleviate the sparsity problem by making use of some auxiliary information, such as the information of both the users and items.

Descriptive Movie Recommendation +1

Offline Reinforcement Learning Under Value and Density-Ratio Realizability: The Power of Gaps

no code implementations25 Mar 2022 Jinglin Chen, Nan Jiang

We consider a challenging theoretical problem in offline reinforcement learning (RL): obtaining sample-efficiency guarantees with a dataset lacking sufficient coverage, under only realizability-type assumptions for the function approximators.

Offline RL Reinforcement Learning (RL)

Adaptable Semantic Compression and Resource Allocation for Task-Oriented Communications

no code implementations19 Apr 2022 Chuanhong Liu, Caili Guo, Yang Yang, Nan Jiang

To solve the problem, both compression ratio and resource allocation are optimized for the task-oriented communication system to maximize the success probability of tasks.

Interaction-Grounded Learning with Action-inclusive Feedback

no code implementations16 Jun 2022 Tengyang Xie, Akanksha Saran, Dylan J. Foster, Lekan Molu, Ida Momennejad, Nan Jiang, Paul Mineiro, John Langford

Consider the problem setting of Interaction-Grounded Learning (IGL), in which a learner's goal is to optimally interact with the environment with no explicit reward to ground its policies.

Brain Computer Interface

On the Statistical Efficiency of Reward-Free Exploration in Non-Linear RL

no code implementations21 Jun 2022 Jinglin Chen, Aditya Modi, Akshay Krishnamurthy, Nan Jiang, Alekh Agarwal

We study reward-free reinforcement learning (RL) under general non-linear function approximation, and establish sample efficiency and hardness results under various standard structural assumptions.

Reinforcement Learning (RL)

A Few Expert Queries Suffices for Sample-Efficient RL with Resets and Linear Value Approximation

no code implementations18 Jul 2022 Philip Amortila, Nan Jiang, Dhruv Madeka, Dean P. Foster

Towards establishing the minimal amount of expert queries needed, we show that, in the same setting, any learner whose exploration budget is polynomially-bounded (in terms of $d, H,$ and $|\mathcal{A}|$) will require at least $\tilde\Omega(\sqrt{d})$ oracle calls to recover a policy competing with the expert's value function.

Imitation Learning Reinforcement Learning (RL)

On the Value of Behavioral Representations for Dense Retrieval

no code implementations11 Aug 2022 Nan Jiang, Dhivya Eswaran, Choon Hui Teo, Yexiang Xue, Yesh Dattatreya, Sujay Sanghavi, Vishy Vishwanathan

We consider text retrieval within dense representational space in real-world settings such as e-commerce search where (a) document popularity and (b) diversity of queries associated with a document have a skewed distribution.

Retrieval Text Retrieval

The Role of Coverage in Online Reinforcement Learning

no code implementations9 Oct 2022 Tengyang Xie, Dylan J. Foster, Yu Bai, Nan Jiang, Sham M. Kakade

Coverage conditions -- which assert that the data logging distribution adequately covers the state space -- play a fundamental role in determining the sample complexity of offline reinforcement learning.

Efficient Exploration Offline RL +2

Beyond the Return: Off-policy Function Estimation under User-specified Error-measuring Distributions

no code implementations27 Oct 2022 Audrey Huang, Nan Jiang

Off-policy evaluation often refers to two related tasks: estimating the expected return of a policy and estimating its value function (or other functions of interest, such as density ratios).

Off-policy evaluation

ARMOR: A Model-based Framework for Improving Arbitrary Baseline Policies with Offline Data

no code implementations8 Nov 2022 Tengyang Xie, Mohak Bhardwaj, Nan Jiang, Ching-An Cheng

We propose a new model-based offline RL framework, called Adversarial Models for Offline Reinforcement Learning (ARMOR), which can robustly learn policies to improve upon an arbitrary baseline policy regardless of data coverage.

Offline RL

Information Bottleneck-Inspired Type Based Multiple Access for Remote Estimation in IoT Systems

no code implementations19 Dec 2022 Meiyi Zhu, Chunyan Feng, Caili Guo, Nan Jiang, Osvaldo Simeone

Type-based multiple access (TBMA) is a semantics-aware multiple access protocol for remote inference.

Offline Learning in Markov Games with General Function Approximation

no code implementations6 Feb 2023 Yuheng Zhang, Yu Bai, Nan Jiang

We study offline multi-agent reinforcement learning (RL) in Markov games, where the goal is to learn an approximate equilibrium -- such as Nash equilibrium and (Coarse) Correlated Equilibrium -- from an offline dataset pre-collected from the game.

Multi-agent Reinforcement Learning Reinforcement Learning (RL)

Reinforcement Learning in Low-Rank MDPs with Density Features

no code implementations4 Feb 2023 Audrey Huang, Jinglin Chen, Nan Jiang

As a central technical challenge, the additive error of occupancy estimation is incompatible with the multiplicative definition of data coverage.

reinforcement-learning Reinforcement Learning (RL) +1

Adversarial Model for Offline Reinforcement Learning

no code implementations NeurIPS 2023 Mohak Bhardwaj, Tengyang Xie, Byron Boots, Nan Jiang, Ching-An Cheng

We propose a novel model-based offline Reinforcement Learning (RL) framework, called Adversarial Model for Offline Reinforcement Learning (ARMOR), which can robustly learn policies to improve upon an arbitrary reference policy regardless of data coverage.

reinforcement-learning Reinforcement Learning (RL)

LM-Switch: Lightweight Language Model Conditioning in Word Embedding Space

no code implementations22 May 2023 Chi Han, Jialiang Xu, Manling Li, Yi Fung, Chenkai Sun, Nan Jiang, Tarek Abdelzaher, Heng Ji

As pre-training and fine-tuning are costly and might negatively impact model performance, it is desired to efficiently adapt an existing model to different conditions such as styles, sentiments or narratives, when facing different audiences or scenarios.

Language Modelling Word Embeddings

Symbolic Regression via Control Variable Genetic Programming

1 code implementation25 May 2023 Nan Jiang, Yexiang Xue

CVGP starts by fitting simple expressions involving a small set of independent variables using genetic programming, under controlled experiments where other variables are held as constants.

regression Symbolic Regression

The Optimal Approximation Factors in Misspecified Off-Policy Value Function Estimation

no code implementations25 Jul 2023 Philip Amortila, Nan Jiang, Csaba Szepesvári

Theoretical guarantees in reinforcement learning (RL) are known to suffer multiplicative blow-up factors with respect to the misspecification error of function approximation.

Off-policy evaluation

Marginalized Importance Sampling for Off-Environment Policy Evaluation

no code implementations4 Sep 2023 Pulkit Katdare, Nan Jiang, Katherine Driggs-Campbell

This paper proposes a new approach to evaluate the real-world performance of agent policies prior to deploying them in the real world.

Reinforcement Learning (RL)

Mitigating the Alignment Tax of RLHF

no code implementations12 Sep 2023 Yong Lin, Hangyu Lin, Wei Xiong, Shizhe Diao, Jianmeng Liu, Jipeng Zhang, Rui Pan, Haoxiang Wang, Wenbin Hu, Hanning Zhang, Hanze Dong, Renjie Pi, Han Zhao, Nan Jiang, Heng Ji, Yuan YAO, Tong Zhang

Building on the analysis and the observation that averaging different layers of the transformer leads to significantly different reward-tax trade-offs, we propose Adaptive Model Averaging (AMA) to adaptively find various combination ratios of model layers.

Common Sense Reasoning Continual Learning

Racing Control Variable Genetic Programming for Symbolic Regression

1 code implementation13 Sep 2023 Nan Jiang, Yexiang Xue

A selection scheme similar to that used in selecting good symbolic equations in the genetic programming process is implemented to ensure that promising experiment schedules eventually win over the average ones.

regression Symbolic Regression

Solving Satisfiability Modulo Counting for Symbolic and Statistical AI Integration With Provable Guarantees

no code implementations16 Sep 2023 Jinzhao Li, Nan Jiang, Yexiang Xue

Solving SMC is challenging because of its highly intractable nature($\text{NP}^{\text{PP}}$-complete), incorporating statistical inference and symbolic reasoning.

Decision Making

Single-view 3D Scene Reconstruction with High-fidelity Shape and Texture

no code implementations1 Nov 2023 Yixin Chen, Junfeng Ni, Nan Jiang, Yaowei Zhang, Yixin Zhu, Siyuan Huang

Reconstructing detailed 3D scenes from single-view images remains a challenging task due to limitations in existing approaches, which primarily focus on geometric shape recovery, overlooking object appearances and fine shape details.

3D Object Reconstruction 3D Reconstruction +5

Nova$^+$: Generative Language Models for Binaries

no code implementations22 Nov 2023 Nan Jiang, Chengxiao Wang, Kevin Liu, Xiangzhe Xu, Lin Tan, Xiangyu Zhang

We build Nova$^+$ to further boost Nova using two new pre-training tasks, i. e., optimization generation and optimization level prediction, which are designed to learn binary optimization and align equivalent binaries.

Code Translation Compiler Optimization +2

Iterative Preference Learning from Human Feedback: Bridging Theory and Practice for RLHF under KL-Constraint

no code implementations18 Dec 2023 Wei Xiong, Hanze Dong, Chenlu Ye, Ziqi Wang, Han Zhong, Heng Ji, Nan Jiang, Tong Zhang

This includes an iterative version of the Direct Preference Optimization (DPO) algorithm for online settings, and a multi-step rejection sampling strategy for offline scenarios.

Language Modelling Large Language Model

Vertical Symbolic Regression

no code implementations19 Dec 2023 Nan Jiang, Md Nasim, Yexiang Xue

The first few steps in vertical discovery are significantly cheaper than the horizontal path, as their search is in reduced hypothesis spaces involving a small set of variables.

regression Symbolic Regression

Harnessing Density Ratios for Online Reinforcement Learning

no code implementations18 Jan 2024 Philip Amortila, Dylan J. Foster, Nan Jiang, Ayush Sekhari, Tengyang Xie

The theories of offline and online reinforcement learning, despite having evolved in parallel, have begun to show signs of the possibility for a unification, with algorithms and analysis techniques for one setting often having natural counterparts in the other.

Offline RL reinforcement-learning

Vertical Symbolic Regression via Deep Policy Gradient

1 code implementation1 Feb 2024 Nan Jiang, Md Nasim, Yexiang Xue

We propose Vertical Symbolic Regression using Deep Policy Gradient (VSR-DPG) and demonstrate that VSR-DPG can recover ground-truth equations involving multiple input variables, significantly beyond both deep reinforcement learning-based approaches and previous VSR variants.

Decision Making regression +1

A Theoretical Analysis of Nash Learning from Human Feedback under General KL-Regularized Preference

no code implementations11 Feb 2024 Chenlu Ye, Wei Xiong, Yuheng Zhang, Nan Jiang, Tong Zhang

In this work, we provide theoretical insights for a recently proposed learning paradigm, Nash learning from human feedback (NLHF), which considered a general preference model and formulated the alignment process as a game between two competitive LLMs.

On the Curses of Future and History in Future-dependent Value Functions for Off-policy Evaluation

no code implementations22 Feb 2024 Yuheng Zhang, Nan Jiang

We study off-policy evaluation (OPE) in partially observable environments with complex observations, with the goal of developing estimators whose guarantee avoids exponential dependence on the horizon.

Off-policy evaluation

Scaling Up Dynamic Human-Scene Interaction Modeling

no code implementations13 Mar 2024 Nan Jiang, Zhiyuan Zhang, Hongjie Li, Xiaoxuan Ma, Zan Wang, Yixin Chen, Tengyu Liu, Yixin Zhu, Siyuan Huang

Confronting the challenges of data scarcity and advanced motion synthesis in human-scene interaction modeling, we introduce the TRUMANS dataset alongside a novel HSI motion synthesis method.

Motion Synthesis

STMGF: An Effective Spatial-Temporal Multi-Granularity Framework for Traffic Forecasting

no code implementations8 Apr 2024 Zhengyang Zhao, Haitao Yuan, Nan Jiang, Minxiao Chen, Ning Liu, Zengxiang Li

Accurate Traffic Prediction is a challenging task in intelligent transportation due to the spatial-temporal aspects of road networks.

Traffic Prediction

Towards Effective Next POI Prediction: Spatial and Semantic Augmentation with Remote Sensing Data

no code implementations22 Mar 2024 Nan Jiang, Haitao Yuan, Jianing Si, Minxiao Chen, Shangguang Wang

The next point-of-interest (POI) prediction is a significant task in location-based services, yet its complexity arises from the consolidation of spatial and semantic intent.

A Note on Loss Functions and Error Compounding in Model-based Reinforcement Learning

no code implementations15 Apr 2024 Nan Jiang

This note clarifies some confusions (and perhaps throws out more) around model-based reinforcement learning and their theoretical understanding in the context of deep RL.

Model-based Reinforcement Learning

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