activity
19972023
most citedDiscovering Emerging Topics in Social Streams via Link Anomaly Detection

29 citations · 79 across the 22 of their papers we have counts for

collaborators

22 papers

cs.LG2023

Adaptive Topological Feature via Persistent Homology: Filtration Learning for Point Clouds

Naoki Nishikawa, Yuichi Ike, Kenji Yamanishi

Machine learning for point clouds has been attracting much attention, with many applications in various fields, such as shape recognition and material science. For enhancing the ac…

stat.ML2023

Tight and fast generalization error bound of graph embedding in metric space

Atsushi Suzuki, Atsushi Nitanda, Taiji Suzuki +3

Recent studies have experimentally shown that we can achieve in non-Euclidean metric space effective and efficient graph embedding, which aims to obtain the vertices' representatio…

cs.LG2023

Detecting Signs of Model Change with Continuous Model Selection Based on Descriptive Dimensionality

Kenji Yamanishi, So Hirai

We address the issue of detecting changes of models that lie behind a data stream. The model refers to an integer-valued structural information such as the number of free parameter…

cs.LG2021

Generalization Error Bound for Hyperbolic Ordinal Embedding

Atsushi Suzuki, Atsushi Nitanda, Jing Wang +3

Hyperbolic ordinal embedding (HOE) represents entities as points in hyperbolic space so that they agree as well as possible with given constraints in the form of entity i is more s…

stat.ML2020

Detecting Hierarchical Changes in Latent Variable Models

Shintaro Fukushima, Kenji Yamanishi

This paper addresses the issue of detecting hierarchical changes in latent variable models (HCDL) from data streams. There are three different levels of changes for latent variable…

cs.LG2020★ 5 cited

Word2vec Skip-gram Dimensionality Selection via Sequential Normalized Maximum Likelihood

Pham Thuc Hung, Kenji Yamanishi

In this paper, we propose a novel information criteria-based approach to select the dimensionality of the word2vec Skip-gram (SG). From the perspective of the probability theory, S…

eess.IV2020★ 11 cited

A Novel Global Spatial Attention Mechanism in Convolutional Neural Network for Medical Image Classification

Linchuan Xu, Jun Huang, Atsushi Nitanda +2

Spatial attention has been introduced to convolutional neural networks (CNNs) for improving both their performance and interpretability in visual tasks including image classificati…

cs.LG2020

Mixture Complexity and Its Application to Gradual Clustering Change Detection

Shunki Kyoya, Kenji Yamanishi

In model-based clustering using finite mixture models, it is a significant challenge to determine the number of clusters (cluster size). It used to be equal to the number of mixtur…

stat.AP2020

Detecting Change Signs with Differential MDL Change Statistics for COVID-19 Pandemic Analysis

Kenji Yamanishi, Linchuan Xu, Ryo Yuki +2

We are concerned with the issue of detecting changes and their signs from a data stream. For example, when given time series of COVID-19 cases in a region, we may raise early warni…

stat.ML2020★ 2 cited

Online Robust and Adaptive Learning from Data Streams

Shintaro Fukushima, Atsushi Nitanda, Kenji Yamanishi

In online learning from non-stationary data streams, it is necessary to learn robustly to outliers and to adapt quickly to changes in the underlying data generating mechanism. In t…

cs.LG2019★ 1 cited

Descriptive Dimensionality and Its Characterization of MDL-based Learning and Change Detection

Kenji Yamanishi

This paper introduces a new notion of dimensionality of probabilistic models from an information-theoretic view point. We call it the "descriptive dimension"(Ddim). We show that Dd…

physics.soc-ph2019★ 16 cited

Long-tailed distributions of inter-event times as mixtures of exponential distributions

Makoto Okada, Kenji Yamanishi, Naoki Masuda

Inter-event times of various human behavior are apparently non-Poissonian and obey long-tailed distributions as opposed to exponential distributions, which correspond to Poisson pr…

stat.ML2018

Adaptive Minimax Regret against Smooth Logarithmic Losses over High-Dimensional -Balls via Envelope Complexity

Kohei Miyaguchi, Kenji Yamanishi

We develop a new theoretical framework, the \emph{envelope complexity}, to analyze the minimax regret with logarithmic loss functions and derive a Bayesian predictor that adaptivel…

stat.ML2018

Stable Geodesic Update on Hyperbolic Space and its Application to Poincare Embeddings

Yosuke Enokida, Atsushi Suzuki, Kenji Yamanishi

A hyperbolic space has been shown to be more capable of modeling complex networks than a Euclidean space. This paper proposes an explicit update rule along geodesics in a hyperboli…

stat.ML2018★ 2 cited

High-dimensional Penalty Selection via Minimum Description Length Principle

Kohei Miyaguchi, Kenji Yamanishi

We tackle the problem of penalty selection of regularization on the basis of the minimum description length (MDL) principle. In particular, we consider that the design space of the…

math.ST2018★ 2 cited

Exact Calculation of Normalized Maximum Likelihood Code Length Using Fourier Analysis

Atsushi Suzuki, Kenji Yamanishi

The normalized maximum likelihood code length has been widely used in model selection, and its favorable properties, such as its consistency and the upper bound of its statistical…

stat.ML2017★ 3 cited

Grafting for Combinatorial Boolean Model using Frequent Itemset Mining

Taito Lee, Shin Matsushima, Kenji Yamanishi

This paper introduces the combinatorial Boolean model (CBM), which is defined as the class of linear combinations of conjunctions of Boolean attributes. This paper addresses the is…

cs.IT2017★ 5 cited

Upper Bound on Normalized Maximum Likelihood Codes for Gaussian Mixture Models

So Hirai, Kenji Yamanishi

This paper shows that the normalized maximum likelihood~(NML) code-length calculated in [1] is an upper bound on the NML code-length strictly calculated for the Gaussian Mixture Mo…

stat.ML2016★ 1 cited

Predicting Glaucoma Visual Field Loss by Hierarchically Aggregating Clustering-based Predictors

Motohide Higaki, Kai Morino, Hiroshi Murata +2

This study addresses the issue of predicting the glaucomatous visual field loss from patient disease datasets. Our goal is to accurately predict the progress of the disease in indi…

cs.LG2012★ 2 cited

Normalized Maximum Likelihood Coding for Exponential Family with Its Applications to Optimal Clustering

So Hirai, Kenji Yamanishi

We are concerned with the issue of how to calculate the normalized maximum likelihood (NML) code-length. There is a problem that the normalization term of the NML code-length may d…

stat.ML2011★ 29 cited

Discovering Emerging Topics in Social Streams via Link Anomaly Detection

Toshimitsu Takahashi, Ryota Tomioka, Kenji Yamanishi

Detection of emerging topics are now receiving renewed interest motivated by the rapid growth of social networks. Conventional term-frequency-based approaches may not be appropriat…

cmp-lg1997

Document Classification Using a Finite Mixture Model

Hang Li, Kenji Yamanishi

We propose a new method of classifying documents into categories. The simple method of conducting hypothesis testing over word-based distributions in categories suffers from the da…