RIKEN Center for Advanced Intelligence Project

Nearly Tight Spectral Sparsification of Directed Hypergraphs by a Simple Iterative Sampling Algorithm

Spectral hypergraph sparsification, an attempt to extend well-known spectral graph sparsification to hypergraphs, has been extensively studied over the past few years. For undirected hypergraphs, Kapralov, Krauthgamer, Tardos, and Yoshida (2022) have proved an $$\varepsilon $$ -s...

Unsupervised machine learning for automated crystal orientation mapping on noisy 4D-STEM data

Abstract Four-dimensional scanning transmission electron microscopy (4D-STEM) is a high-throughput measurement used to comprehensively acquire diffraction patterns across a region of interest in a specimen. While the measurement is useful for identifying crystallographic microstr...

Randomized Subspace Gradient Method for Constrained Optimization

We propose randomized subspace gradient methods for high-dimensional constrained optimization. Whereas there are related studies on unconstrained optimization problems, there are relatively few for constrained optimization problems because of the difficulty of handling constraint...

Ground states of the defocusing nonlinear Schrödinger equation with a point interaction in dimensions 2 and 3

Abstract This paper is concerned with ground states of the defocusing nonlinear Schrödinger equation with a point interaction, $$ \textrm{i} \partial _t \psi = -\Delta _\alpha \psi + \psi |\psi |^{p - 2} \quad \text {in} \quad \mathbb {R} \times \mathbb {R}^N, $$ i ∂ t ψ = - Δ α...

Mental Health Profiles in Community Acupuncture Clinics in Japan: A Multicenter Exploratory Cross-Sectional Study

Background: The mental health status of patients attending acupuncture clinics in Japan remains poorly understood. Objective: To characterize mental health profiles of individuals attending acupuncture clinics across Japan. Design: Cross-sectional study. Setting: Ten rural and ur...

ProvMind: provenance-grounded reasoning for materials synthesis

Materials process optimization requires reasoning over routes, conditions, tools and material-flow dependencies, yet most computational formulations flatten synthesis procedures into text or ordered steps. We introduce MatProcBench, a provenance-grounded benchmark constructed fro...

Boundedness of Composition Operators in Orlicz–Morrey Spaces

ABSTRACT In this paper, we investigate the necessary and sufficient conditions for the boundedness of composition operators on Orlicz–Morrey spaces. Our results encompass Lebesgue and generalized Morrey spaces as special cases. In addition, we characterize the boundedness of comp...

SoccerSynth-detection: a synthetic dataset for soccer player detection

Abstract Soccer player detection is a fundamental task in soccer video analysis, supporting downstream applications such as event analysis and tactical reconstruction. However, annotated soccer player data from broadcast videos are difficult to obtain and use at scale because of...

Spontaneous segmentation of slow slip events on a homogeneous planar fault

Abstract Slow slip events (SSEs) are transient aseismic fault slip events that often display segmentation along strike. While fault segmentation is commonly attributed to physical heterogeneities, numerical studies have shown that segmentation can also occur on homogeneous planar...

Generalizing molecular design via flexible search space control

Abstract Recent advances in generative artificial intelligence have made in silico molecular design a powerful approach for exploring chemical space toward specific goals. However, despite the need for trial-and-error adjustment of generative strategies and reward formulations, m...

Strong connections of locally clustered neurons in the upper-layer cortex underlie schizophrenia-related auditory deviance detection

The detection of unexpected sounds, or auditory deviance detection, is thought to be achieved by comparing prediction signals and sensory inputs in the auditory cortex. This process is markedly impaired in patients with schizophrenia. However, the local circuit properties underly...

dd-RCMA-ES: CMA-ES with Projection-Based Restricted Covariance Matrix Adaptation for High-Dimensional Problems

This paper addresses the computational challenges of the covariance matrix adaptation evolution strategy (CMA-ES) in high-dimensional optimization of an objective function \(f:\mathbb{R}^{n}\to\mathbb{R}\) where \(n\gg 100\) , particularly for problems exhibiting sparse-sensitivi...

Evidence for latent regularities in echolocation-guided flight behaviour of bats

Abstract Echolocating bats navigate complex environments with remarkable agility, yet it remains unclear whether their flight trajectories are governed by reproducible internal policies shared within a species and across the controlled environments examined. To address this quest...

Visualizing diagnosis-associated AMPA receptor-related [11C]K-2 PET SUVR patterns across psychiatric disorders using weakly supervised UMAP

AMPA receptors (AMPARs) mediate fast excitatory neurotransmission and play a central role in synaptic function, with accumulating evidence in psychiatric disorders. Using [ 11 C]K-2 PET to assess AMPAR-related signals in vivo, we examined whether regional standardized uptake valu...

Potential EnergySurfaces of Environment-SensitiveFlapping Fluorophores: FLAP

Abstract A series of FLAP molecules are one of the functional fluorescent probes that can sense subtle changes in local environments such as viscosity, polymer free volume, and external mechanical force. In this work, potential energy surfaces (PESs) of a representative Flexible...