Nako Sung


2022

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On the Effect of Pretraining Corpora on In-context Learning by a Large-scale Language Model
Seongjin Shin | Sang-Woo Lee | Hwijeen Ahn | Sungdong Kim | HyoungSeok Kim | Boseop Kim | Kyunghyun Cho | Gichang Lee | Woomyoung Park | Jung-Woo Ha | Nako Sung
Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

Many recent studies on large-scale language models have reported successful in-context zero- and few-shot learning ability. However, the in-depth analysis of when in-context learning occurs is still lacking. For example, it is unknown how in-context learning performance changes as the training corpus varies. Here, we investigate the effects of the source and size of the pretraining corpus on in-context learning in HyperCLOVA, a Korean-centric GPT-3 model. From our in-depth investigation, we introduce the following observations: (1) in-context learning performance heavily depends on the corpus domain source, and the size of the pretraining corpus does not necessarily determine the emergence of in-context learning, (2) in-context learning ability can emerge when a language model is trained on a combination of multiple corpora, even when each corpus does not result in in-context learning on its own, (3) pretraining with a corpus related to a downstream task does not always guarantee the competitive in-context learning performance of the downstream task, especially in the few-shot setting, and (4) the relationship between language modeling (measured in perplexity) and in-context learning does not always correlate: e.g., low perplexity does not always imply high in-context few-shot learning performance.

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AlphaTuning: Quantization-Aware Parameter-Efficient Adaptation of Large-Scale Pre-Trained Language Models
Se Jung Kwon | Jeonghoon Kim | Jeongin Bae | Kang Min Yoo | Jin-Hwa Kim | Baeseong Park | Byeongwook Kim | Jung-Woo Ha | Nako Sung | Dongsoo Lee
Findings of the Association for Computational Linguistics: EMNLP 2022

There are growing interests in adapting large-scale language models using parameter-efficient fine-tuning methods. However, accelerating the model itself and achieving better inference efficiency through model compression has not been thoroughly explored yet.Model compression could provide the benefits of reducing memory footprints, enabling low-precision computations, and ultimately achieving cost-effective inference.To combine parameter-efficient adaptation and model compression, we propose AlphaTuning consisting of post-training quantization of the pre-trained language model and fine-tuning only some parts of quantized parameters for a target task.Specifically, AlphaTuning works by employing binary-coding quantization, which factorizes the full-precision parameters into binary parameters and a separate set of scaling factors.During the adaptation phase, the binary values are frozen for all tasks, while the scaling factors are fine-tuned for the downstream task.We demonstrate that AlphaTuning, when applied to GPT-2 and OPT, performs competitively with full fine-tuning on a variety of downstream tasks while achieving >10x compression ratio under 4-bit quantization and >1,000x reduction in the number of trainable parameters.

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Keep Me Updated! Memory Management in Long-term Conversations
Sanghwan Bae | Donghyun Kwak | Soyoung Kang | Min Young Lee | Sungdong Kim | Yuin Jeong | Hyeri Kim | Sang-Woo Lee | Woomyoung Park | Nako Sung
Findings of the Association for Computational Linguistics: EMNLP 2022

Remembering important information from the past and continuing to talk about it in the present are crucial in long-term conversations. However, previous literature does not deal with cases where the memorized information is outdated, which may cause confusion in later conversations. To address this issue, we present a novel task and a corresponding dataset of memory management in long-term conversations, in which bots keep track of and bring up the latest information about users while conversing through multiple sessions. In order to support more precise and interpretable memory, we represent memory as unstructured text descriptions of key information and propose a new mechanism of memory management that selectively eliminates invalidated or redundant information. Experimental results show that our approach outperforms the baselines that leave the stored memory unchanged in terms of engagingness and humanness, with larger performance gap especially in the later sessions.

2021

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What Changes Can Large-scale Language Models Bring? Intensive Study on HyperCLOVA: Billions-scale Korean Generative Pretrained Transformers
Boseop Kim | HyoungSeok Kim | Sang-Woo Lee | Gichang Lee | Donghyun Kwak | Jeon Dong Hyeon | Sunghyun Park | Sungju Kim | Seonhoon Kim | Dongpil Seo | Heungsub Lee | Minyoung Jeong | Sungjae Lee | Minsub Kim | Suk Hyun Ko | Seokhun Kim | Taeyong Park | Jinuk Kim | Soyoung Kang | Na-Hyeon Ryu | Kang Min Yoo | Minsuk Chang | Soobin Suh | Sookyo In | Jinseong Park | Kyungduk Kim | Hiun Kim | Jisu Jeong | Yong Goo Yeo | Donghoon Ham | Dongju Park | Min Young Lee | Jaewook Kang | Inho Kang | Jung-Woo Ha | Woomyoung Park | Nako Sung
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing

GPT-3 shows remarkable in-context learning ability of large-scale language models (LMs) trained on hundreds of billion scale data. Here we address some remaining issues less reported by the GPT-3 paper, such as a non-English LM, the performances of different sized models, and the effect of recently introduced prompt optimization on in-context learning. To achieve this, we introduce HyperCLOVA, a Korean variant of 82B GPT-3 trained on a Korean-centric corpus of 560B tokens. Enhanced by our Korean-specific tokenization, HyperCLOVA with our training configuration shows state-of-the-art in-context zero-shot and few-shot learning performances on various downstream tasks in Korean. Also, we show the performance benefits of prompt-based learning and demonstrate how it can be integrated into the prompt engineering pipeline. Then we discuss the possibility of materializing the No Code AI paradigm by providing AI prototyping capabilities to non-experts of ML by introducing HyperCLOVA studio, an interactive prompt engineering interface. Lastly, we demonstrate the potential of our methods with three successful in-house applications.