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 Our research interest is the development of mathematical theories and measurement methods for inverse problems which invert the law of causality to identify the cause of a phenomenon from its results. These problems are ubiquitous in engineering - non-invasive measurements in biomedical engineering, non-destructive inspection of structures and materials, searching for victims buried in rubble after earthquake, indoor navigation for cyber-physical systems - all of these can be treated as inverse problems.
 Our laboratory aims to derive mathematically rigorous and computationally efficient algorithms as well as develop novel sensors for inverse problems.

What's new


・2024/3/22 Mr. Yota Fujii (B4) gave a presentation titled "タイリング構造に基づく細胞シートの配向制御" at the The 71st JSAP Spring Meeting 2024.
・2024/3/18 Mr. Kanta Shiku gave a presentation titled "漏洩磁束のフーリエ係数計測による移動する強磁性体丸棒の欠陥定位" at the 令和5年度 第3回 電磁非破壊検査を支援する逆問題解析に関する調査研究委員会.
・2024/3/13-14 Research Associate Hiroki Miyazako gave a presentation titled "タクトイド構造中のトポロジカル欠陥に基づく分子ロボットの変形モデル" at the 第7回分子ロボティクス年次大会.
・2024/3/8 Mr. Kotaro Koyama (B4) gave a presentation titled "Searching people buried in rubble using multi-frequency dipole sound fields" at the Section A Workshop of Instrumentation and Measurement, IEEJ.
・2024/2/16 An article introducing Project Researcher Hiroyuki Miyoshi's research was published in Kagaku Shinbun (Science Newspaper).
・2024/2/5 The co-authored journal paper with Mr. Naohiro Eda (D3) has been published in the Physics in Medicine & Biology.
"Magnetic resonance imaging of blood perfusion rate based on Helmholtz decomposition of heat flux"
・2023/12/28 Prof. Nara gave a presentation titled "電磁気逆問題の数理解法と脳内電気特性再構成・電流源推定への応用" at the 数学と脳科学の連携に向けたワークショップ.
・2023/12/21 The co-authored paper has been published in Journal of Neuroscience Methods.
"Limiting parameter range for cortical-spherical mapping improves activated domain estimation for attention modulated auditory response"
・2023/11/19 Project Researcher Hiroyuki Miyoshi received The Doris Chen PhD Merit Award 2022-2023 from Imperial College London.
・2023/11/16 Research Associate Hiroki Miyazako gave a presentation titled "Dynamics of topological defects in spindle-shaped cell populations on periodic structures" at the 61st Annual Meeting of the Biophysical Society of Japan.
・2023/10/14 Project Researcher Hiroyuki Miyoshi received the Best Poster Award at the 数学・数理科学専攻若手研究者のための異分野・異業種研究交流会2023.
・2023/10/2 Dr. Hiroyuki MIYOSHI has joined our Lab, as a project researcher.
・2023/9/7 Prof. Nara gave a presentation titled "High-resolution imaging of electrical properties inside the human body based on magnetic field interpolation" co-authored with Mr. K. Maeda (fy2022 M2) at SICE2023.
・2023/9/5 Mr. Kenta Matsuuchi (M2) gave a presentation titled "Numerical Verification of Generation of Ultrasound-Driven Bent Flow by Centripetal and Tangential Body Force Field" at the IEEE IUS 2023.
・2023/9/5 Mr. Masato Nakagawa (M2) gave a presentation titled "Spatial Calibration of Airborne Ultrasonic Phased Arrays with Two-Dimensional Visualization of Ultrasound Emissions" at the IEEE IUS 2023.
・2023/9/1 Mr. Naohiro Eda (D3) gave a presentation titled "A method for reconstruction of electrical properties in human bodies without their boundary values" at the 40th Sensing Forum.
・2023/8/31  Mr. Kanta Shiku (M2) gave a presentation titled "Development of differential-type radial Fourier coils for the detection of cracks in cylindrical ferromagnetic rods " at the 40th Sensing Forum.
・2023/7/28 Mr. Kanta Shiku (M2) gave a presentation titled
"差動フーリエコイルを用いた強磁性体丸棒の欠陥の円周方向および軸方向定位"
at the 令和5年度 第1回 電磁非破壊検査を支援する逆問題解析に関する調査研究委員会
・2023/6/26 The co-authored journal paper with Mr. Naohiro Eda (D3) has been published in the IEEE Transactions on Magnetics.
"Reconstruction of the Electrical Properties in Human Bodies Based on the Estimation of the Unmeasurable Magnetic Fields"
・2023/6/26 The co-authored journal paper with Mr. Kanta Shiku (M2) has been published in the IEEE Transactions on Magnetics.
"Circumferential localization of a crack in cylindrical ferromagnetic rods based on the Fourier coefficients of the radial directional magnetic flux leakage"
・2023/6/7 Mr. Kanta Shiku (M2) gave a presentation titled "動径方向漏洩磁束のフーリエ係数を用いた強磁性体丸棒の欠陥の円周方向および軸方向定位" at the 2023年度 非破壊検査総合シンポジウム,
and he received the "令和4年度表面3部門 若手研究 優秀賞" in the 表面NDTワークショップ2023 of the JSNDI.
・2023/5/31 Prof. Nara gave a presentation titled "Reconstruction of electrical properties inside the human body:direct method without an assumption on the boundary values of the electrical properties" at the JSCES 28.
・2023/5/25 Mr. Yuuichi Oosawa (M2) gave a presentation titled "Reconstruction of tangential magnetic fields from radial MEG measurements" at the ISACM and JBBS 2023 OSAKA.
・2023/5/18 Mr. Naohiro Eda (D3) gave a presentation titled "Reconstruction of the Electrical Properties in Human Bodies Based on the Estimation of the Unmeasurable Magnetic Fields" at the INTERMAG 2023.
・2023/5/16 Mr. Kanta Shiku (M2) gave a presentation titled "Circumferential localization of a crack in cylindrical ferromagnetic rods based on the Fourier coefficients of the radial directional magnetic flux leakage" at the INTERMAG 2023.
・2023/4/1 
 New members have joined: Keigo KAWAUCHI(M1), Kazuki NISHINO(M1)
 Lecturer Keisuke Hasegawa transferred to Saitama University.
・2023/3/24 
 Mr. Shun Kotoku (B4) received the 東京大学工学部長賞(研究).
 Mr. Naoki Matsuda (B4) received the 計測自動制御学会 SICE優秀学生賞.
・2023/3/17 Mr. Naoki Matsuda (B4) gave a presentation titled "Control of Cell Alignment Based on a Theory of Nematic Liquid Crystals in Periodic Structures" at the 70th JSAP Spring Meeting 2023.
・2023/3/17 The domestic conference paper "Biomimetic actuation leveraging on-chip buckling deformation of photoresponsive gels" co-authored by research Associate Hiroki Miyazako at the 70th JSAP Spring Meeting 2023.
・2023/3/16 The domestic conference paper "両面4極着磁の永久磁石を使用した鋼棒材外面欠陥検査手法の検討" co-authored by Proffesor Takaaki Nara was presented at the 第26回電磁気応用部門・磁粉・浸透・目視部門・漏れ試験部門合同シンポジウム.
・2023/3/16 Mr. Kanta Shiku (M1) gave a presentation titled "Circumferential localization of a crack in cylindrical ferromagnetic rods using the first order Fourier coefficients of the radial directional magnetic flux leakage" at the 第26回電磁気応用部門・磁粉・浸透・目視部門・漏れ試験部門合同シンポジウム.
・2023/3/7 Mr. Naohiro Eda (D2) gave a presentation titled "Thermal Properties imaging in human bodies based on Helmholtz decomposition of heat flux" at the Technical Committee on Medical Imaging (MI).
・2023/2/24 The journal paper has been published on the arXiv.
"Heterogeneous source model for magnetoenecephalography"
・2023/1/12 Proffesor Takaaki Nara gave an invited lecture entitled
"On biomagnetic inverse problems: Identification of an epileptic focus using magnetoencephalography" at the RIMS Workshop on Inverse Problems, Medical Imaging, and Related Topics.
・2023/1/6 The co-authored journal paper with Mr. Kazuyuki Arikawa(fy2020 B4) has been published in The Journal of the Acoustical Society of America.
"Self-localization of monaural microphone using dipole sound sources"
・2022/12/23 Mr. Kanta Shiku (M1) gave a presentation titled "動径方向漏洩磁束のフーリエ係数計測による丸棒鋼材欠陥の定位" at the 電磁非破壊検査・数値解析調査研究委員会.
・2022/12/9 Proffesor Takaaki Nara gave a keynote lecture entitled "非侵襲計測・非破壊検査のための逆問題解析法" at the Multiphysics Conference 2022.
・2022/11/29 Research Associate Hiroki Miyazako gave a presentation titled "Predictive Design of Orientational Order in Confined Active Nematic Materials" at the 2022 MRS Fall Meeting &Exhibition.
・2022/11/15 Proffesor Nara's review "Inspection of Ferromagnetic Pipes Based on Measurements of Fourier Coefficients of Leakage Magnetic Flux" has been published in the Journal of the JSNDI, vol. 71, issue. 11.
・2022/11/12 Research Associate Hiroki Miyazako gave a presentation titled "複素関数論に基づくアクティブネマチック流体の配向・速度場の計算理論" at the 第6回分子ロボティクス年次大会.
・2022/10/31 The co-authored journal paper with Mr. Motofumi Fushimi has been published in Measurement Sensors.
"A novel reconstruction method for magnetic resonance elastography based on the Helmholtz decomposition"
・2022/10/26 The domestic conference paper "直流磁界の速度効果を利用した鋼棒材外面スリット欠陥検査手法の検討" co-authored by Prof. Nara was presented at the JSNDI 2022年度秋季講演大会.
・2022/10/17 Mr. Naohiro Eda (D2) gave a presentation titled "Helmholtz decomposition-based denoising for electrical properties tomography" at the QMR Lucca.
・2022/10/10 Mr. Masato Nakagawa (M1) gave a presentation titled
"A Spatial Calibration Strategy of Multiple Airborne Ultrasonic Phased Arrays based on Acoustic Beam Steering " at the 2022 IEEE International Conference on Systems, Man and Cybernetics (SMC).
・2022/9/21-22 Our laboratory members presented their research at the 39th Sensing Forum.
 Mr. Masato Nakagawa (M1),
 Title: Position and Posture Estimation of Airborne Ultrasound Phased Arrays by Acoustic Beam Scanning
 Ms. Toko Nakai (M2),
 Title: Reconstruction of elasticity in human bodies using MRI - extraction of shear wave by helmholtz decomposition - 
 Mr. Kenshiro Maeda (M2),
 Title: Interpolation of Magnetic Field Considering Constraint Condition for Reconstruction of Electrical Properties Using MRI
 Ms. Akemi Matsumoto (M2),
 Title: Search System of People Buried in Rubble Using a Smartphone Microphone
 Mr. Naohiro Eda (D2),
 Title: Thermal property imaging of human tissues with MRI based on the Helmholtz decomposition of heat flux
  ・2022/9/22 Ms. Shihori Kozuka (fy2021 M2),Mr. Naohiro Eda (D2) received the 2021年度SICEセンシングフォーラム研究奨励賞.
Title (Ms. Kozuka): Remote sound field measurement using parametric sound generated by scanning of airborne focused ultrasound
Title (Mr. Eda): A Reconstruction Method for the Electrical Properties With Approximation of the Magnetic Field Using Homogeneous Simulation Model
・2022/9/10 Proffesor Takaaki Nara gave a presentation titled "異種ソースモデルに基づく局所的神経電流原推定 −てんかん焦点同定への応用" at the 応用数理学会2022年度年会.
・2022/9/8 Lecturer Keisuke Hasegawa gave a presentation titled "Acoustic Self-Positioning Based on Interpolation of Received Amplitude Map for 2DoF Angular Bessel Beam Scanning (I)" at the SICE Annual Conference 2022.
This presentation has been nominated as a finalist for the 2022 SICE Annual Conference International Award (IA).
・2022/9/8 Ms. Ayumi Matsumoto (M2) gave a presentation titled "Smartphone Localization System for Urban Search and Rescue" at the SICE Annual Conference 2022.
・2022/8/30 Proffesor Takaaki Nara gave a presentation titled "Heterogeneous source model for magnetoencephalography: Combination of a parametric and an imaging approach for separation of a focal source and background activities" at the BIOMAG 2022.
・2022/6/16 Proffesor Takaaki Nara gave an invited lecture entitled "Inverse source problem for Poisson’s equation for identification of an epileptic focus from magnetic field measurements" at CIRM Theoretical and Numerical Trends in Inverse Problems and Control for PDEs, and Hamilton-Jacobi Equation: a French-Italian-Japanese Conference.
・2022/6/15 Professor Takaaki Nara gave a presentation titled "Heterogeneous source model for magnetoenecephalography -combination of a parametric and an imaging approach-" at The 37th Annual Meeting of Japan Biomagnetism and Bioelectromagnetics Society.
・2022/6/6 Awards page is now open.
・2022/5/19 Ms. Toko Nakai (M2) received the 令和3年度電子情報通信学会医用画像研究会奨励賞.
Title: Reconstruction of electrical conductivity and permittivity in human bodies using MRI -Estimation of boundary electric fields based on boundary element methods
・2022/5/18 Mr. Kohei Tsuchiyama (fy2021 B4) received the 69th JSAP Spring Meeting 2022 Poster Award.
Title: A design method for cell alignment based on spatial distributions of topological defects
・2022/5/13 Ms. Ayumi Matsumoto (M2) gave a presentation titled "Direction Estimation System using a Monaural Microphone for Rescuing People Buried Under Rubble" at the IEICE (EA).
・2022/5/9 Mr. Naohiro Eda (D2) gave a presentation titled "Helmholtz Decomposition-Based Method for EPT with Approximation of Unmeasurable Magnetic Field Components Using Homogeneous Simulation Model" at the international conference, ISMRM2022.
・2022/4/20 Professor Takaaki Nara gave an invited lecture entitled "Mathematical approaches to biomagnetic inverse problems: magnetoencephalography (MEG) and magnetic resonance electrical property tomography (MREPT)" at 第14回医用生体電磁気学シンポジウム.
・2022/4/20 Mr. Naohiro Eda (D2) gave a presentation titled “Reconstruction of the electrical properties in humnan bodies based on the estimation of the unmeasurable magnetic field” at 第14回医用生体電磁気学シンポジウム.
With this presentation, Mr. Eda received 医用生体電磁気学研究会若手優秀発表賞.
・2022/4/1 New members have joined: Yuuichi OOSAWA(M1),
Kanta SHIKU(M1), Masato NAKAGAWA(M1), Kenta MATSUUCHI(M1)
・2022/3/26 Professor Takaaki Nara gave an invited lecture entitled "数学に基づく医療診断:てんかん焦点の位置同定" at 第5回先端医工学講演会.
・2022/3/25 Mr. Kohei Tsuchiyama (B4) gave a presentation titled "A design method for cell alignment based on spatial distributions of topological defects" at The 69th JSAP Spring Meeting 2022.
・2022/3/24 Ms. Shihori Koduka (M2) received the SICE Excellent Student Award from the Society of Instrument and Control Engineers.
・2022/3/14 The co-authored journal paper with Mr. Naohiro Eda (D1) will be published in IEEE Transactions on Medical Imaging.
"A Method for Electrical Property Tomography Based on a Three-Dimensional Integral Representation of the Electric Field" (Early Access)
・2022/3/10 Mr. Youta Maeda (M1) gave a presentation titled "収束空中超音波による音響流を用いた局所的な遠隔熱伝達促進" at the 2022 Spring meeting of the Acoustical Society of Japan.
・2022/3/10 Mr. Kouta Nagata (M1) gave a presentation titled "対向超音波フェーズドアレーによる音響流を利用した飛沫拡散抑制の検討" at the 2022 Spring meeting of the Acoustical Society of Japan.
・2022/1/27 Mr. Kenshiro Maeda (M1) gave a presentation titled "Reconstruction of electrical conductivity in human bodies based on phase measurement of high frequency magnetic field using MRI" at the IEICE (MI).
・2022/1/27 Ms. Toko Nakai (M1) gave a presentation titled "Reconstruction of electrical conductivity and permittivity in human bodies using MRI -Estimation of boundary electric fields based on boundary element methods-" at the IEICE (MI).
・2022/1/21 Research Associate Hiroki Miyazako gave a presentation titled "Spatial Control of Topological Defects in Active Nematic Systems by Optimization of Conformal Mappings" at the 第34回自律分散システム・シンポジウム.
・2022/1/19 The co-authored journal paper with Research Associate Hiroki Miyazako has been published in Royal Society Open Science.
"Explicit calculation method for cell alignment in non-circular geometries"
・2021/12/8 The co-authored journal paper with Ms. Honoka Mukai has been published in The Journal of the Acoustical Society of America.
"Sequential Structured Volumetric Ultrasound Holography for Self-Positioning Using Monaural Recording"
・2021/11/26 Research Associate Hiroki Miyazako gave a presentation titled "Cell Alignment and Topological Defects in Two-Dimensional Geometries with Corner Singularities" at the 59th Annual Meeting of the Biophysical of Japan.
・2021/11/22 Research Associate Hiroki Miyazako gave a lecture at the system information discourse meeting of the Dept. Mathematical Engineering and Information Physics.
・2021/10/1 Mr. Naohiro Eda(D1) gave a presentation titled “A Reconstruction Method for the Electrical Properties With Approximation of the Magnetic Field Using Homogeneous Simulation Model” at the 38th Sensing Forum.
・2021/9/30 Mr. Koki Abe(M2) gave a presentation titled “Localization of Mobile Devices Using Rotating Sound Sources” at the 38th Sensing Forum.
・2021/9/30 Ms. Shihori Kozuka(M2) gave a presentation titled “Remote sound field measurement using parametric sound generated by scanning of airborne focused ultrasound” at the 38th Sensing Forum.
・2021/9/30 Mr. Tianyu Yang(M2) gave a presentation titled “Removing Effects of Background Neural Activities Using Maximum Likelihood Estimation for Magnetoencephalographic Inverse Problems” at the 38th Sensing Forum.
・2021/9/10 Research Associate Hiroki Miyazako gave a presentation titled "函数論に基づく細胞配向の数値計算法と実験検証" which Prof. Nara co-authored at The 82nd JSAP Autumn Meeting 2021.
・2021/8/30 We have presented 
“Localization of mobile devices based on a magnetic field generated by a rotating magnetic dipole” and
“Reconstruction of Shear Modulus and Viscosity of Biological Tissues from Displacement Measurement”  at the international conference, IMEKO2021.
・2021/8/27 Prof. Takaaki Nara gave a invited presentation titled "A method for magnetic resonance electrical properties tomography based on Helmholtz' decomposition" at the Inverse problems and nonlinearity(Online, Helsinki).
・2021/6/19 Prof. Takaaki Nara gave a presentation titled "函数論を用いた電気特性再構成逆問題とその三次元化" at the One-day workshop on Applied and Computational Complex Analysis(ACCA2021).
・2021/6/19 Research Associate Hiroki Miyazako gave a presentation titled "函数論に基づく細胞配向場の計算論" at the One-day workshop on Applied and Computational Complex Analysis(ACCA2021).
・2021/5/20 We have presented "Global and Direct Electrical Properties Tomography Method Based on the Linear Integral Equations for Impedivity" at the international conference, ISMRM2021.
・2021/5/20 Mr. Naohiro Eda (D1) gave a presentation titled "An Iterative Method for Electrical Properties Tomography Based on the Helmholtz Decomposition for the Electric Field" at the international conference, ISMRM2021.
・2021/5/17 We have presented "MR Elastography Reconstruction Based on a Linear Integral Equation Derived from the Helmholtz Identity" at the international conference, ISMRM2021.
・2021/4/1 Dr. Yingyi XIAO has joined our Lab, as a project researcher.
New members have joined: Toko NAKAI(M1), Kouta NAGATA(M1), Kenshiro MAEDA(M1), Yota MAEDA(M1), Ayumi MATSUMOTO(M1), Tasuku MIZUNO(M1)