papers

Publications (28)

cs.CL2023

How Does In-Context Learning Help Prompt Tuning?

Simeng Sun, Yang Liu, Dan Iter +2

Fine-tuning large language models is becoming ever more impractical due to their rapidly-growing scale. This motivates the use of parameter-efficient adaptation methods such as pro…

cs.CL2023

Efficiently Upgrading Multilingual Machine Translation Models to Support More Languages

Simeng Sun, Maha Elbayad, Anna Sun +1

With multilingual machine translation (MMT) models continuing to grow in size and number of supported languages, it is natural to reuse and upgrade existing models to save computat…

cs.CV2022

Semantically Video Coding: Instill Static-Dynamic Clues into Structured Bitstream for AI Tasks

Xin Jin, Ruoyu Feng, Simeng Sun +3

Traditional media coding schemes typically encode image/video into a semantic-unknown binary stream, which fails to directly support downstream intelligent tasks at the bitstream l…

cs.CL2020

Hard-Coded Gaussian Attention for Neural Machine Translation

Weiqiu You, Simeng Sun, Mohit Iyyer

Recent work has questioned the importance of the Transformer's multi-headed attention for achieving high translation quality. We push further in this direction by developing a "har…

cs.CV2022

Image Coding for Machines with Omnipotent Feature Learning

Ruoyu Feng, Xin Jin, Zongyu Guo +6

Image Coding for Machines (ICM) aims to compress images for AI tasks analysis rather than meeting human perception. Learning a kind of feature that is both general (for AI tasks) a…

cs.CL2021

Revisiting Simple Neural Probabilistic Language Models

Simeng Sun, Mohit Iyyer

Recent progress in language modeling has been driven not only by advances in neural architectures, but also through hardware and optimization improvements. In this paper, we revisi…

cs.CL2022

ChapterBreak: A Challenge Dataset for Long-Range Language Models

Simeng Sun, Katherine Thai, Mohit Iyyer

While numerous architectures for long-range language models (LRLMs) have recently been proposed, a meaningful evaluation of their discourse-level language understanding capabilitie…

cs.CL2021

Do Long-Range Language Models Actually Use Long-Range Context?

Simeng Sun, Kalpesh Krishna, Andrew Mattarella-Micke +1

Language models are generally trained on short, truncated input sequences, which limits their ability to use discourse-level information present in long-range context to improve th…

cs.CL2024

How much do contextualized representations encode long-range context?

Simeng Sun, Cheng-Ping Hsieh

We analyze contextual representations in neural autoregressive language models, emphasizing long-range contexts that span several thousand tokens. Our methodology employs a perturb…

cs.MM2023

GraphIQA: Learning Distortion Graph Representations for Blind Image Quality Assessment

Simeng Sun, Tao Yu, Jiahua Xu +2

A good distortion representation is crucial for the success of deep blind image quality assessment (BIQA). However, most previous methods do not effectively model the relationship…

cs.CL2021

Energy-Based Reranking: Improving Neural Machine Translation Using Energy-Based Models

Sumanta Bhattacharyya, Amirmohammad Rooshenas, Subhajit Naskar +3

The discrepancy between maximum likelihood estimation (MLE) and task measures such as BLEU score has been studied before for autoregressive neural machine translation (NMT) and res…

cs.CL2023

Exploring the impact of low-rank adaptation on the performance, efficiency, and regularization of RLHF

Simeng Sun, Dhawal Gupta, Mohit Iyyer

During the last stage of RLHF, a large language model is aligned to human intents via PPO training, a process that generally requires large-scale computational resources. In this t…

cs.CL2025

An empirical study on the limitation of Transformers in program trace generation

Simeng Sun

We study Transformers on the task \emph{program trace generation} (PTG), where models produce step-by-step execution traces for synthetic programs. Unlike existing algorithmic prob…

cs.CV2021

Learning Omni-frequency Region-adaptive Representations for Real Image Super-Resolution

Xin Li, Xin Jin, Tao Yu +4

Traditional single image super-resolution (SISR) methods that focus on solving single and uniform degradation (i.e., bicubic down-sampling), typically suffer from poor performance…

cs.PL2025

L0-Reasoning Bench: Evaluating Procedural Correctness in Language Models via Simple Program Execution

Simeng Sun, Cheng-Ping Hsieh, Faisal Ladhak +3

Complex reasoning tasks often rely on the ability to consistently and accurately apply simple rules across incremental steps, a foundational capability which we term "level-0" reas…

cs.CL2025

SWAN-GPT: An Efficient and Scalable Approach for Long-Context Language Modeling

Krishna C. Puvvada, Faisal Ladhak, Santiago Akle Serrano +8

We present a decoder-only Transformer architecture that robustly generalizes to sequence lengths substantially longer than those seen during training. Our model, SWAN-GPT, interlea…

cs.CL2021

Alternative Input Signals Ease Transfer in Multilingual Machine Translation

Simeng Sun, Angela Fan, James Cross +4

Recent work in multilingual machine translation (MMT) has focused on the potential of positive transfer between languages, particularly cases where higher-resourced languages can b…

cs.LG2026

Nemotron 3 Super: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning

NVIDIA, :, Aakshita Chandiramani +544

We describe the pre-training, post-training, and quantization of Nemotron 3 Super, a 120 billion (active 12 billion) parameter hybrid Mamba-Attention Mixture-of-Experts model. Nemo…

cs.CL2025

NVIDIA Nemotron 3: Efficient and Open Intelligence

NVIDIA, :, Aaron Blakeman +356

We introduce the Nemotron 3 family of models - Nano, Super, and Ultra. These models deliver strong agentic, reasoning, and conversational capabilities. The Nemotron 3 family uses a…

cs.CL2026

Nemotron 3 Ultra: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning

NVIDIA, :, Aaron Blakeman +571

We introduce Nemotron 3 Ultra, a 550 billion total and 55 billion active parameter Mixture-of-Experts Hybrid Mamba-Attention language model. We pre-trained Nemotron 3 Ultra on 20 t…

cs.LG2025

nGPT: Normalized Transformer with Representation Learning on the Hypersphere

Ilya Loshchilov, Cheng-Ping Hsieh, Simeng Sun +1

We propose a novel neural network architecture, the normalized Transformer (nGPT) with representation learning on the hypersphere. In nGPT, all vectors forming the embeddings, MLP,…

cs.CL2021

IGA : An Intent-Guided Authoring Assistant

Simeng Sun, Wenlong Zhao, Varun Manjunatha +5

While large-scale pretrained language models have significantly improved writing assistance functionalities such as autocomplete, more complex and controllable writing assistants h…

cs.CL2025

Nemotron 3 Nano: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning

NVIDIA, :, Aaron Blakeman +311

We present Nemotron 3 Nano 30B-A3B, a Mixture-of-Experts hybrid Mamba-Transformer language model. Nemotron 3 Nano was pretrained on 25 trillion text tokens, including more than 3 t…

cs.CL2024

RULER: What's the Real Context Size of Your Long-Context Language Models?

Cheng-Ping Hsieh, Simeng Sun, Samuel Kriman +5

The needle-in-a-haystack (NIAH) test, which examines the ability to retrieve a piece of information (the "needle") from long distractor texts (the "haystack"), has been widely adop…

eess.IV2020

Multi-scale Grouped Dense Network for VVC Intra Coding

Xin Li, Simeng Sun, Zhizheng Zhang +1

Versatile Video Coding (H.266/VVC) standard achieves better image quality when keeping the same bits than any other conventional image codec, such as BPG, JPEG, and etc. However, i…

cs.CL2024

Suri: Multi-constraint Instruction Following for Long-form Text Generation

Chau Minh Pham, Simeng Sun, Mohit Iyyer

Existing research on instruction following largely focuses on tasks with simple instructions and short responses. In this work, we explore multi-constraint instruction following fo…

cs.CL2024

TopicGPT: A Prompt-based Topic Modeling Framework

Chau Minh Pham, Alexander Hoyle, Simeng Sun +2

Topic modeling is a well-established technique for exploring text corpora. Conventional topic models (e.g., LDA) represent topics as bags of words that often require "reading the t…

cs.CL2023

PEARL: Prompting Large Language Models to Plan and Execute Actions Over Long Documents

Simeng Sun, Yang Liu, Shuohang Wang +2

Strategies such as chain-of-thought prompting improve the performance of large language models (LLMs) on complex reasoning tasks by decomposing input examples into intermediate ste…