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

**・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.

**・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)