Masafumi Oyamada

Senior Researcher

NEC Corporation


I am a senior researcher at NEC Corporation. I am now a principal investigator of knowledge-based learning team of Data Science Research Laboratories at NEC Corporation. I received my Ph.D. at University of Tsukuba in March 2018 under supervision of Prof. Hiroyuki Kitagawa.

My research interests are on helping data analysis using data management technologies (DB) and machine learning technologies (ML).



  • IPSJ Yamashita SIG Research Award, 2019


  • Best Paper Runner-Up, 2018

    WebDB Forum

  • Annual Conference Award, 2016


  • Best Honorable Poster, 2015


  • Best Paper Runner-Up, 2015


  • Honorable Poster, 2014


  • Dept. Chair Award, 2013

    University of Tsukuba

  • Honorable Student Talk, 2013



  • PhD in Computer Science, 2018

    University of Tsukuba

  • MEng in Computer Science, 2013

    University of Tsukuba

  • BSE in Computer Science, 2011

    University of Tsukuba

We are hiring (Interneship / Full-time)

Our research team (knowledge-based learning) at NEC Corporation is seeking for motivated full-time researchers / internship students who are passionate in working on interdisciplinary research issues that arise from real-world enterprise business. We aim to contribute to both industries and academics. Our research results are commercialized and used in various enterprise companies such as retailers and consumer products companies. We publish our results in top-level venues of computer science (e.g., AAAI, ICDE, ICDM, BigData).

Research topics include but not limited to:

  • Highly scalable ML-aided data integration (DB + ML + HPC)
  • Crowd-sourcing for data cleaning (DB + ML + HCI)
  • Machine learning on data sketches (ML + DB)
  • Knowledge-driven AutoML based on source code analysis (SE + NLP + ML)

Preferred Skills

  • Business-level English (writing & speaking)
  • Basic coding skills for data science tasks
  • Basic knowledge on data structures and algorithms
  • Academic experience (publication) in one of the following research area:
    • Database Systems (DB)
    • Machine Learning (ML)
    • Software Engineering (SE)
    • Natural Language Processing (NLP)
    • Human-Computer Interaction (HCI)
    • Information Retrieval (IR)


Please drop me an E-mail with your CV if you are interested in working with us.


See my GitHub for list of software I have crafted. Here are some selected stuffs.



Provides fully-configurable hardware keyboard functionalities for web browsing on iOS (iPadOS)


Yet another keyboard remapping tool for X environment


An interactive grep tool in your terminal


Allows you to bind commands to key sequences in Mozilla Firefox


A Lisp implementation and REPL written in JavaScript, which supports static-scoping, lexical-closure, macro, and basic special forms


A parser for org-mode notation written in JavaScript


Provides zsh like completion for minibuffer in Emacs

Chaotic Canvas

A chaos fractal generator written in JavaScript


Add jsdoc-related functionalities for Emacs


A major-mode for LEMON Parser Generator.


Complete list of publications is also available.

Learning from Unsure Responses

Meimei: An Efficient Probabilistic Approach for Semantically Annotating Tables

Compressed Vector Set: A Fast and Space-Efficient Data Mining Framework

Link Prediction for Isolated Nodes in Heterogeneous Network by Topic-Based Co-clustering

MOARLE: Matrix Operation Accelerator Based on Run-Length Encoding

Data Stream Processing with Concurrency Control

Continuous Query Processing with Concurrency Control: Reading Updatable Resources Consistently

A recent trend in data stream processing shows the use of advanced continuous queries (CQs) that reference non-streaming resources such as relational data in databases and machine learning models. Since non-streaming resources could be shared among multiple systems, resources may be updated by the systems during the CQ execution. As a consequence, CQs may reference resources inconsistently, and lead to a wide range of problems from inappropriate results to fatal system failures.

Efficient Invocation of Transaction Sequences Triggered by Data Streams



Senior Researcher

NEC Corporation

Apr 2017 – Present Tokyo, Japan
Principal investigator of a research team (knowledge-based learning). Research topics include

  • Data Management (Data Integration, Data Indexing, …)
  • Machine Learning (Multi-label Classification)
  • Human-Computer Interaction (Crowd Computing)
  • Information Extraction (Knowledge Extraction)


NEC Corporation

Apr 2013 – Mar 2017 Tokyo, Japan
Research on customer behavior data analytics. Research topics include

  • Bayesian Modeling of Customer Behavior
  • Context-aware Recommendation
  • Statistical Relational Learning

Research Staff (Internship)

NTT Research Laboratories

Aug 2011 – Aug 2011 Tokyo, Japan
Research and development on a data stream processing system.

Software Engineer (Part-time)

Clear-Code Inc.

May 2011 – Mar 2013 Tokyo, Japan
Software development. Developed web browser extensions, E-mail reader extensions, and search engine backends. (JavaScript, Ruby, C++).

Software Engineer (Internship)

Hatena Inc.

Aug 2010 – Aug 2010 Tokyo, Japan
Developed a browser extension of social bookmark web service (Hatena Bookmark) for Safari.