activity
20192026
most citedA Survey on The Expressive Power of Graph Neural Networks

83 citations · 160 across the 26 of their papers we have counts for

collaborators

27 papers

cs.AI2026

Training Graph Foundation Models on The Web Graph

Ryoma Sato

We introduce Acacia, a graph foundation model, trained on the web graph. Acacia (i) supports arbitrary feature dimensionalities and semantics without additional training, (ii) supp…

cs.LG2024

Parameter-free Clipped Gradient Descent Meets Polyak

Yuki Takezawa, Han Bao, Ryoma Sato +2

Gradient descent and its variants are de facto standard algorithms for training machine learning models. As gradient descent is sensitive to its hyperparameters, we need to tune th…

cs.LG2023★ 4 cited

Embarrassingly Simple Text Watermarks

Ryoma Sato, Yuki Takezawa, Han Bao +2

We propose Easymark, a family of embarrassingly simple yet effective watermarks. Text watermarking is becoming increasingly important with the advent of Large Language Models (LLM)…

cs.CL2023★ 2 cited

Necessary and Sufficient Watermark for Large Language Models

Yuki Takezawa, Ryoma Sato, Han Bao +2

In recent years, large language models (LLMs) have achieved remarkable performances in various NLP tasks. They can generate texts that are indistinguishable from those written by h…

cs.LG2023★ 2 cited

Beyond Exponential Graph: Communication-Efficient Topologies for Decentralized Learning via Finite-time Convergence

Yuki Takezawa, Ryoma Sato, Han Bao +2

Decentralized learning has recently been attracting increasing attention for its applications in parallel computation and privacy preservation. Many recent studies stated that the…

cs.LG2023★ 1 cited

Graph Neural Networks can Recover the Hidden Features Solely from the Graph Structure

Ryoma Sato

Graph Neural Networks (GNNs) are popular models for graph learning problems. GNNs show strong empirical performance in many practical tasks. However, the theoretical properties hav…

cs.LG2022

Active Learning from the Web

Ryoma Sato

Labeling data is one of the most costly processes in machine learning pipelines. Active learning is a standard approach to alleviating this problem. Pool-based active learning firs…

cs.LG2022★ 3 cited

Momentum Tracking: Momentum Acceleration for Decentralized Deep Learning on Heterogeneous Data

Yuki Takezawa, Han Bao, Kenta Niwa +2

SGD with momentum is one of the key components for improving the performance of neural networks. For decentralized learning, a straightforward approach using momentum is Distribute…

cs.IR2022

Towards Principled User-side Recommender Systems

Ryoma Sato

Traditionally, recommendation algorithms have been designed for service developers. However, recently, a new paradigm called user-side recommender systems has been proposed and the…

cs.DL2022

Twin Papers: A Simple Framework of Causal Inference for Citations via Coupling

Ryoma Sato, Makoto Yamada, Hisashi Kashima

The research process includes many decisions, e.g., how to entitle and where to publish the paper. In this paper, we introduce a general framework for investigating the effects of…

stat.ML2022★ 4 cited

Approximating 1-Wasserstein Distance with Trees

Makoto Yamada, Yuki Takezawa, Ryoma Sato +3

Wasserstein distance, which measures the discrepancy between distributions, shows efficacy in various types of natural language processing (NLP) and computer vision (CV) applicatio…

cs.IR2022

CLEAR: A Fully User-side Image Search System

Ryoma Sato

We use many search engines on the Internet in our daily lives. However, they are not perfect. Their scoring function may not model our intent or they may accept only text queries e…

cs.CL2022

Word Tour: One-dimensional Word Embeddings via the Traveling Salesman Problem

Ryoma Sato

Word embeddings are one of the most fundamental technologies used in natural language processing. Existing word embeddings are high-dimensional and consume considerable computation…

cs.IR2021

Retrieving Black-box Optimal Images from External Databases

Ryoma Sato

Suppose we have a black-box function (e.g., deep neural network) that takes an image as input and outputs a value that indicates preference. How can we retrieve optimal images with…

cs.AI2021★ 2 cited

Fixed Support Tree-Sliced Wasserstein Barycenter

Yuki Takezawa, Ryoma Sato, Zornitsa Kozareva +2

The Wasserstein barycenter has been widely studied in various fields, including natural language processing, and computer vision. However, it requires a high computational cost to…

cs.IR2021★ 1 cited

Enumerating Fair Packages for Group Recommendations

Ryoma Sato

Package-to-group recommender systems recommend a set of unified items to a group of people. Different from conventional settings, it is not easy to measure the utility of group rec…

cs.LG2021★ 11 cited

Re-evaluating Word Mover's Distance

Ryoma Sato, Makoto Yamada, Hisashi Kashima

The word mover's distance (WMD) is a fundamental technique for measuring the similarity of two documents. As the crux of WMD, it can take advantage of the underlying geometry of th…

cs.IR2021

Private Recommender Systems: How Can Users Build Their Own Fair Recommender Systems without Log Data?

Ryoma Sato

Fairness is a crucial property in recommender systems. Although some online services have adopted fairness aware systems recently, many other services have not adopted them yet. In…

cs.LG2021

Supervised Tree-Wasserstein Distance

Yuki Takezawa, Ryoma Sato, Makoto Yamada

To measure the similarity of documents, the Wasserstein distance is a powerful tool, but it requires a high computational cost. Recently, for fast computation of the Wasserstein di…

cs.DL2020★ 4 cited

Poincare: Recommending Publication Venues via Treatment Effect Estimation

Ryoma Sato, Makoto Yamada, Hisashi Kashima

Choosing a publication venue for an academic paper is a crucial step in the research process. However, in many cases, decisions are based solely on the experience of researchers, w…

cs.LG2020

Fast Unbalanced Optimal Transport on a Tree

Ryoma Sato, Makoto Yamada, Hisashi Kashima

This study examines the time complexities of the unbalanced optimal transport problems from an algorithmic perspective for the first time. We reveal which problems in unbalanced op…

cs.LG2020★ 83 cited

A Survey on The Expressive Power of Graph Neural Networks

Ryoma Sato

Graph neural networks (GNNs) are effective machine learning models for various graph learning problems. Despite their empirical successes, the theoretical limitations of GNNs have…

cs.LG2020★ 9 cited

Random Features Strengthen Graph Neural Networks

Ryoma Sato, Makoto Yamada, Hisashi Kashima

Graph neural networks (GNNs) are powerful machine learning models for various graph learning tasks. Recently, the limitations of the expressive power of various GNN models have bee…

stat.ML2020★ 10 cited

Fast and Robust Comparison of Probability Measures in Heterogeneous Spaces

Ryoma Sato, Marco Cuturi, Makoto Yamada +1

Comparing two probability measures supported on heterogeneous spaces is an increasingly important problem in machine learning. Such problems arise when comparing for instance two p…