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Principal Research Engineer at Samsung R&D Institute (UK).
PhD in Data Science from the University of Edinburgh (SMASH group).

I am interested in building computational agents that process natural language, and react in a manner that brings value to our lives. Towards this vision, my recent work has focused on safety for generative artificial intelligence (GenAI), as supported by large language models (LLMs). For instance, check out this paper (under review) about a method for parameter-efficient guardrailing LLMs. I have also worked on problems in Computational Social Science, Figurative Language Comprehension, Machine Translation, and Computer Vision. For more details, check out my publications below.

silviu dot vlad dot oprea at gmail dot com

My CV in PDF format is here.


News

See more news here.


Work

  • 2024 - present: Principal Research Engineer at Samsung R&D Institute UK

    I've recently been working on LLM guardrailing. For instance, check out our paper, LoRA-Guard: Parameter-Efficient Guardrail Adaptation for Content Moderation of Large Language Models (arxiv; under review); we introduce a parameter-efficient method for LLM guardrailing. It outperforms existing approaches with 100-1000x lower parameter overhead, enabling on-device content moderation.

  • 2022 - 2024: Applied Scientist at Amazon Alexa AI

    I've worked on improving the ability of large language models (LLMs) to generate responses that would provide Alexa customers with a more delightful experience.

  • 2021: Applied Scientist (Intern) at Amazon Alexa AI

    At Amazon, I worked with Elisabeth Kwan, Molly Xia, Christos Christodoulopoulos, Dave Palfrey, and Stephen Teskey on language generation using language models.

  • 2020: Research Scientist (Intern) at Huawei

    At Huawei, I worked with Haytham Assem and Sourav Dutta on learning transformations between monolingual word embedding spaces, to enable unsupervised translation and transfer learning to low-resource languages. Check out our COLING 2022 paper based on this work.

  • 2019: Researcher at Frontier Development Lab

    At Frontier Developemnt Lab, we built a flood segmentation model. In the process, we collaborated with the European Space Agency and UNICEF. The model has now been deployed by SpaceX on an actual satellite 🛰.

    Our work was covered by this post from the University of Oxford; and by several media outlets: 1, 2, 3, 4, 5. Check out our Nature (Scientific Reports) paper and the video of the rocket launch 🚀

  • 2014 - 2017: Engineer at VisualDNA and TheySay

    During this time, I was an engineer at two tech startups. First, a software engineer at VisualDNA, a data science and management platform, where I worked on data aggregation and reporting using Scala and the Scalding interface to Hadoop. After VisualDNA, I spent some time as a contractor. Next, I was an artificial intelligence engineer at TheySay, a startup providing text analytics services, where I used technologies such as Scala and MongoDB.

    Both startups were acquired, see this article about VisualDNA, and this one about TheySay.

  • 2012: Guest Researcher at the National Institute for Standards and Technology

    I worked with Bruce Miller on extending LaTeXML, a TeX parser that he wrote in Perl. The goal of my extenssion was to convert TikZ graphics to SVG. See this paper that mentions my work.


Education

  • 2018 - 2023: PhD in Data Science at the University of Edinburgh

    Check out my thesis, Computational Sarcasm Detection and Understanding in Online Communication.

    In summary, I used computational methods to detect and understand the phenomenon of sarcasm, as it is manifested in online textual communication, together with my supervisors, Walid Magdy, Bonnie Webber, and Maria Wolters.

    More specifically, I built a dataset of texts annotated for sarcasm (ACL 2020 paper), introduced sarcasm detection models (ACL 2019 paper), and also organised a competition encouraging the community to build such models (SemEval 2022 paper). I showed that people of similar socio-demographic backgrounds understand each other's sarcasm more often than people of dissimilar backgrounds (CSCW 2022 paper). Finally, I built a sarcastic chatbot (EMNLP 2021 demo), and investigated when it is appropriate for chatbots to be sarcastic, and how they should formulate their utterances (ACL 2022 paper).

    Along the way, I had fun as an intern at Frontier Development Lab in 2019 (20201 Nature (Scientific Reports) paper), at Huawei in 2020 (COLING 2022 paper), and at Amazon Alexa AI in 2021 (paper in the baking 👨🏻‍🍳). See below, in the Work section.

  • 2017 - 2018: MRes in Data Science at the University of Edinburgh

    I used computational methods to detect the presence of sarcasm in tweets, together with my supervisor, Walid Magdy.

  • 2012 - 2013: MSc in Computer Science at the University of Oxford

    I worked with Phil Blunsom on building character-level language models for the Romanian language using recurrent neural networks.

  • 2009 - 2012: BSc in Computer Science at Jacobs University Bremen

    This is where my interest in natural language processing was triggered, working with Michael Kohlhase.


Teaching

  • 2021: Lab demonstrator for Text Technologies in Data Science at the University of Edinburgh.
  • 2010 and 2011: Teaching assistant for Programming in C/C++ at Jacobs University Bremen.

Media coverage

Our paper, LoRA-Guard: Parameter-Efficient Guardrail Adaptation for Content Moderation of Large Language Models, under review, has been covered by:

Our paper, Towards global flood mapping onboard low cost satellites with machine learning, published in Nature (Scientific Reports) in 2021, was covered by the following articles:


Patents

European patent office

  • Processing communications in a computing arrangement for semantic understanding and interpretation of code-switching
    Sourav Dutta, Silviu Vlad Oprea, Haytham Assem, and Hu Peng
    Patent WO2022069030A1 issued from application PCT/EP2020/077336. 2022.
    html

My Google Patents page is here.


Publications

Safety and Bias

  • LoRA-Guard: Parameter-Efficient Guardrail Adaptation for Content Moderation of Large Language Models
    Hayder Elesedy, Pedro M. Esperança, Silviu Vlad Oprea, and Mete Ozay
    Under review. 2024.
    pdf

Figurative language comprehension

  • Sarcasm Detection is Way Too Easy! An Empirical Comparison of Human and Machine Sarcasm Detection
    Ibrahim Abu Farha, Steven Wilson, Silviu Vlad Oprea, and Walid Magdy
    Findings of the Association for Computational Linguistics. 2022.
    pdf
  • SemEval-2022 Task 6: iSarcasmEval, Intended Sarcasm Detection in English and Arabic
    Ibrahim Abu Farha, Silviu Vlad Oprea, Steven Wilson, and Walid Magdy
    Proceedings of the 16th International Workshop on Semantic Evaluation (SemEval-2022). 2022.
    pdfvideo
  • iSarcasm: A Dataset of Intended Sarcasm
    Silviu Vlad Oprea, and Walid Magdy
    Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics. 2020.
    pdfvideo
  • Exploring Author Context for Detecting Intended vs Perceived Sarcasm
    Silviu Vlad Oprea, and Walid Magdy
    Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics. 2019.
    pdfvideo

Computational social science

  • Should a Chatbot be Sarcastic? Understanding User Preferences Towards Sarcasm Generation
    Silviu Vlad Oprea, Steven Wilson, and Walid Magdy
    Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics. 2022.
    pdfvideo
  • The Effect of Sociocultural Variables on Sarcasm Communication Online
    Silviu Vlad Oprea, and Walid Magdy
    Proceedings of the ACM on Human-Computer Interaction. 2020.
    pdfhtml

Controllable text generation

  • Chandler: An Explainable Sarcastic Response Generator
    Silviu Vlad Oprea, Steven Wilson, and Walid Magdy
    Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing: System Demonstrations. 2021.
    pdfvideo

Machine translation

  • Multi-Stage Framework with Refinement Based Point Set Registration for Unsupervised Bi-Lingual Word Alignment
    Silviu Vlad Oprea, Sourav Dutta, and Haytham Assem
    Proceedings of the 29th International Conference on Computational Linguistics. 2022.
    pdf

Computer vision

  • Towards global flood mapping onboard low cost satellites with machine learning
    Gonzalo Mateo-Garcia*, Joshua Veitch-Michaelis*, Lewis Smith*, Silviu Vlad Oprea, Guy Schumann, Yarin Gal, Atılım Güneş Baydin, and Dietmar Backes
    Nature (Scientific Reports). 2021.
    html

* indicates equal contribution. Check the full list of publications on my Google Scholar profile.


Talks

This list does not include conference presentations of my papers.

  • Talk about my work on sarcasm detection and understanding at Oakland University, MI, USA (online).
  • Talk about my work on sarcasm detection and understanding at the Technical University of Cluj-Napoca, Romania (online).