141 research outputs found
The BLue Amazon Brain (BLAB): A Modular Architecture of Services about the Brazilian Maritime Territory
We describe the first steps in the development of an artificial agent focused
on the Brazilian maritime territory, a large region within the South Atlantic
also known as the Blue Amazon. The "BLue Amazon Brain" (BLAB) integrates a
number of services aimed at disseminating information about this region and its
importance, functioning as a tool for environmental awareness. The main service
provided by BLAB is a conversational facility that deals with complex questions
about the Blue Amazon, called BLAB-Chat; its central component is a controller
that manages several task-oriented natural language processing modules (e.g.,
question answering and summarizer systems). These modules have access to an
internal data lake as well as to third-party databases. A news reporter
(BLAB-Reporter) and a purposely-developed wiki (BLAB-Wiki) are also part of the
BLAB service architecture. In this paper, we describe our current version of
BLAB's architecture (interface, backend, web services, NLP modules, and
resources) and comment on the challenges we have faced so far, such as the lack
of training data and the scattered state of domain information. Solving these
issues presents a considerable challenge in the development of artificial
intelligence for technical domains
Overview of ImageArg-2023: The First Shared Task in Multimodal Argument Mining
This paper presents an overview of the ImageArg shared task, the first
multimodal Argument Mining shared task co-located with the 10th Workshop on
Argument Mining at EMNLP 2023. The shared task comprises two classification
subtasks - (1) Subtask-A: Argument Stance Classification; (2) Subtask-B: Image
Persuasiveness Classification. The former determines the stance of a tweet
containing an image and a piece of text toward a controversial topic (e.g., gun
control and abortion). The latter determines whether the image makes the tweet
text more persuasive. The shared task received 31 submissions for Subtask-A and
21 submissions for Subtask-B from 9 different teams across 6 countries. The top
submission in Subtask-A achieved an F1-score of 0.8647 while the best
submission in Subtask-B achieved an F1-score of 0.5561.Comment: In The 10th Argument Mining Workshop, held in conjunction with The
Conference on Empirical Methods in Natural Language Processing (EMNLP),
December 202
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Adapting Automatic Summarization to New Sources of Information
English-language news articles are no longer necessarily the best source of information. The Web allows information to spread more quickly and travel farther: first-person accounts of breaking news events pop up on social media, and foreign-language news articles are accessible to, if not immediately understandable by, English-speaking users. This thesis focuses on developing automatic summarization techniques for these new sources of information.
We focus on summarizing two specific new sources of information: personal narratives, first-person accounts of exciting or unusual events that are readily found in blog entries and other social media posts, and non-English documents, which must first be translated into English, often introducing translation errors that complicate the summarization process. Personal narratives are a very new area of interest in natural language processing research, and they present two key challenges for summarization. First, unlike many news articles, whose lead sentences serve as summaries of the most important ideas in the articles, personal narratives provide no such shortcuts for determining where important information occurs in within them; second, personal narratives are written informally and colloquially, and unlike news articles, they are rarely edited, so they require heavier editing and rewriting during the summarization process. Non-English documents, whether news or narrative, present yet another source of difficulty on top of any challenges inherent to their genre: they must be translated into English, potentially introducing translation errors and disfluencies that must be identified and corrected during summarization.
The bulk of this thesis is dedicated to addressing the challenges of summarizing personal narratives found on the Web. We develop a two-stage summarization system for personal narrative that first extracts sentences containing important content and then rewrites those sentences into summary-appropriate forms. Our content extraction system is inspired by contextualist narrative theory, using changes in writing style throughout a narrative to detect sentences containing important information; it outperforms both graph-based and neural network approaches to sentence extraction for this genre. Our paraphrasing system rewrites the extracted sentences into shorter, standalone summary sentences, learning to mimic the paraphrasing choices of human summarizers more closely than can traditional lexicon- or translation-based paraphrasing approaches.
We conclude with a chapter dedicated to summarizing non-English documents written in low-resource languages – documents that would otherwise be unreadable for English-speaking users. We develop a cross-lingual summarization system that performs even heavier editing and rewriting than does our personal narrative paraphrasing system; we create and train on large amounts of synthetic errorful translations of foreign-language documents. Our approach produces fluent English summaries from disdisfluent translations of non-English documents, and it generalizes across languages
Emotion and Sentiment Guided Paraphrasing
Paraphrase generation, a.k.a. paraphrasing, is a common and important task in
natural language processing. Emotional paraphrasing, which changes the emotion
embodied in a piece of text while preserving its meaning, has many potential
applications, including moderating online dialogues and preventing
cyberbullying. We introduce a new task of fine-grained emotional paraphrasing
along emotion gradients, that is, altering the emotional intensities of the
paraphrases in fine-grained settings following smooth variations in affective
dimensions while preserving the meaning of the original text. We reconstruct
several widely used paraphrasing datasets by augmenting the input and target
texts with their fine-grained emotion labels. Then, we propose a framework for
emotion and sentiment guided paraphrasing by leveraging pre-trained language
models for conditioned text generation. Extensive evaluation of the fine-tuned
models suggests that including fine-grained emotion labels in the paraphrase
task significantly improves the likelihood of obtaining high-quality
paraphrases that reflect the desired emotions while achieving consistently
better scores in paraphrase metrics such as BLEU, ROUGE, and METEOR.Comment: 13th Workshop on Computational Approaches to Subjectivity, Sentiment
& Social Media Analysis (WASSA) 2023 at The 61st Annual Meeting of the
Association for Computational Linguistics (ACL) 2023. arXiv admin note:
substantial text overlap with arXiv:2212.0329
Automatic generation of large-scale paraphrases
Research on paraphrase has mostly focussed on lexical or syntactic variation within individual sentences. Our concern is with larger-scale paraphrases, from multiple sentences or paragraphs to entire documents. In this paper
we address the problem of generating paraphrases of large chunks of texts. We ground our discussion through a
worked example of extending an existing NLG system to accept as input a source text, and to generate a range of fluent semantically-equivalent alternatives, varying not only at the lexical and syntactic levels, but also in document structure and layout
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Towards Robust Long-form Text Generation Systems
Text generation is an important emerging AI technology that has seen significant research advances in recent years. Due to its closeness to how humans communicate, mastering text generation technology can unlock several important applications such as intelligent chat-bots, creative writing assistance, or newer applications like task-agnostic few-shot learning. Most recently, the rapid scaling of large language models (LLMs) has resulted in systems like ChatGPT, capable of generating fluent, coherent and human-like text. However, despite their remarkable capabilities, LLMs still suffer from several limitations, particularly when generating long-form text. In particular, (1) long-form generated text is filled with factual inconsistencies to world knowledge and the input prompt; (2) it is difficult to accurately evaluate the quality of long-form generated text; (3) it is difficult to identify whether a piece of long-form text was AI-generated, a task necessary to prevent widespread misinformation and plagiarism.
In this thesis I design algorithms aimed at making progress towards these three issues in current LLMs. I will first describe a retrieval-augmented system we built for long-form question answering, to improve factual correctness of long-form generated text. However, a careful empirical analysis reveals issues related to input/output consistency of generated text, and an inherent difficulty in evaluation. I will then describe our model RankGen, which uses large-scale contrastive learning on documents to significantly outperform competing long-form text generation methods to generate text more faithful to the input. Next, I will describe our efforts to improve human evaluation of long-form generation (issue #2) by proposing the LongEval guidelines. LongEval is a set of three simple empirically-motivated ideas to make human evaluation of long-form generation more consistent, less expensive, and cognitively easier for evaluators. Finally, I describe my work on AI-generated text detection (issue #3), and showcase the brittleness of existing methods to paraphrasing attacks I designed. I will describe a simple new AI-generated text detection algorithm using information retrieval, which is significantly more robust to paraphrasing attacks.
Finally, I conclude this thesis with some future research directions that I am excited about, including plan-based long-form text generation, and a deeper dive into understanding large language model training dynamics
Semantic Parsing in Limited Resource Conditions
This thesis explores challenges in semantic parsing, specifically focusing on
scenarios with limited data and computational resources. It offers solutions
using techniques like automatic data curation, knowledge transfer, active
learning, and continual learning.
For tasks with no parallel training data, the thesis proposes generating
synthetic training examples from structured database schemas. When there is
abundant data in a source domain but limited parallel data in a target domain,
knowledge from the source is leveraged to improve parsing in the target domain.
For multilingual situations with limited data in the target languages, the
thesis introduces a method to adapt parsers using a limited human translation
budget. Active learning is applied to select source-language samples for manual
translation, maximizing parser performance in the target language. In addition,
an alternative method is also proposed to utilize machine translation services,
supplemented by human-translated data, to train a more effective parser.
When computational resources are limited, a continual learning approach is
introduced to minimize training time and computational memory. This maintains
the parser's efficiency in previously learned tasks while adapting it to new
tasks, mitigating the problem of catastrophic forgetting.
Overall, the thesis provides a comprehensive set of methods to improve
semantic parsing in resource-constrained conditions.Comment: PhD thesis, year of award 2023, 172 page
Evolution of A Common Vector Space Approach to Multi-Modal Problems
A set of methods to address computer vision problems has been developed. Video un- derstanding is an activate area of research in recent years. If one can accurately identify salient objects in a video sequence, these components can be used in information retrieval and scene analysis. This research started with the development of a course-to-fine frame- work to extract salient objects in video sequences. Previous work on image and video frame background modeling involved methods that ranged from simple and efficient to accurate but computationally complex. It will be shown in this research that the novel approach to implement object extraction is efficient and effective that outperforms the existing state-of-the-art methods. However, the drawback to this method is the inability to deal with non-rigid motion.
With the rapid development of artificial neural networks, deep learning approaches are explored as a solution to computer vision problems in general. Focusing on image and text, the image (or video frame) understanding can be achieved using CVS. With this concept, modality generation and other relevant applications such as automatic im- age description, text paraphrasing, can be explored. Specifically, video sequences can be modeled by Recurrent Neural Networks (RNN), the greater depth of the RNN leads to smaller error, but that makes the gradient in the network unstable during training.To overcome this problem, a Batch-Normalized Recurrent Highway Network (BNRHN) was developed and tested on the image captioning (image-to-text) task. In BNRHN, the highway layers are incorporated with batch normalization which diminish the gradient vanishing and exploding problem. In addition, a sentence to vector encoding framework that is suitable for advanced natural language processing is developed. This semantic text embedding makes use of the encoder-decoder model which is trained on sentence paraphrase pairs (text-to-text). With this scheme, the latent representation of the text is shown to encode sentences with common semantic information with similar vector rep- resentations. In addition to image-to-text and text-to-text, an image generation model is developed to generate image from text (text-to-image) or another image (image-to- image) based on the semantics of the content. The developed model, which refers to the Multi-Modal Vector Representation (MMVR), builds and encodes different modalities into a common vector space that achieve the goal of keeping semantics and conversion between text and image bidirectional. The concept of CVS is introduced in this research to deal with multi-modal conversion problems. In theory, this method works not only on text and image, but also can be generalized to other modalities, such as video and audio. The characteristics and performance are supported by both theoretical analysis and experimental results. Interestingly, the MMVR model is one of the many possible ways to build CVS. In the final stages of this research, a simple and straightforward framework to build CVS, which is considered as an alternative to the MMVR model, is presented
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Chatbot Interaction with Artificial Intelligence:human data augmentation with T5 and language transformer ensemble for text classification
In this work we present the Chatbot Interaction with Artificial Intelligence (CI-AI) framework as an approach to the training of a transformer based chatbot-like architecture for task classification with a focus on natural human interaction with a machine as opposed to interfaces, code, or formal commands. The intelligent system augments human-sourced data via artificial paraphrasing in order to generate a large set of training data for further classical, attention, and language transformation-based learning approaches for Natural Language Processing (NLP). Human beings are asked to paraphrase commands and questions for task identification for further execution of algorithms as skills. The commands and questions are split into training and validation sets. A total of 483 responses were recorded. Secondly, the training set is paraphrased by the T5 model in order to augment it with further data. Seven state-of-the-art transformer-based text classification algorithms (BERT, DistilBERT, RoBERTa, DistilRoBERTa, XLM, XLM-RoBERTa, and XLNet) are benchmarked for both sets after fine-tuning on the training data for two epochs. We find that all models are improved when training data is augmented by the T5 model, with an average increase of classification accuracy by 4.01%. The best result was the RoBERTa model trained on T5 augmented data which achieved 98.96% classification accuracy. Finally, we found that an ensemble of the five best-performing transformer models via Logistic Regression of output label predictions led to an accuracy of 99.59% on the dataset of human responses. A highly-performing model allows the intelligent system to interpret human commands at the social-interaction level through a chatbot-like interface (e.g. “Robot, can we have a conversation?”) and allows for better accessibility to AI by non-technical users
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