論文 - 山田　寛喜

RTL Evaluation of ℓ2-Norm Approximation with Rotated ℓ1-Norm for 2-Tuple Arrays

Shu Abe, Yuya Kodama, Hiroyoshi Yamada, Shogo Muramatsu

APSIPA Transactions on Signal and Information Processing   14 ( 1 )   2025年

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Now Publishers  

DOI： 10.1561/116.20240068

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Fundamental Polarimetric Scattering Analysis For Detecting Oriented Manmade Objects Using Polarimetric Correlation Coefficients

Ryoichi Sato, Toshifum Moriyama, Yuya Arima, Yoshio Yamaguchi, Hiroyoshi Yamada, Ryu Sugimoto, Chiaki Tsutsumi, Ryosuke Nakamura

2023 8th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)   2023年10月

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掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

DOI： 10.1109/apsar58496.2023.10388936

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Far-Field Radar Cross-Section Determination from Near-Field 3-D Synthetic Aperture Imaging with Arbitrary Antenna-Scanning Surfaces

Takuma Watanabe, Hiroyoshi Yamada

IEEE Transactions on Antennas and Propagation   1 - 1   2022年

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tap.2022.3161491

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Accuracy improvement of human motion recognition with MW-FMCW radar using CNN

Fumiya Sakagami, Hiroyoshi Yamada, Shogo Muramatsu

2020 International Symposium on Antennas and Propagation, ISAP 2020   173 - 174   2021年1月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Institute of Electrical and Electronics Engineers Inc.  

Human Motion Recognition (HMR) using radar has been expected to be applied to human monitoring. Radar-based HMR can be realized by extracting features by deep learning from radar motion-sensing data. In this paper, three 2-D domains (Time-Doppler, Time-Range, and Range-Doppler) are analyzed as the motion data. The motion classification results using Convolutional Neural Network (CNN) shows that multiple domains improve classification accuracy. In addition, we show the motion analysis results with high range resolution including DOA, and show that further accuracy improvement can be expected.

DOI： 10.23919/ISAP47053.2021.9391487

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Orientation Estimation of Surface Cracks in Metals Based on Intensity Maximization of Polarimetric Circular Synthetic Aperture Radar Images

Takuma Watanabe, Hiroyoshi Yamada

IEEE Transactions on Instrumentation and Measurement   70   1 - 14   2021年

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tim.2021.3122168

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Synthetic Aperture Imaging of Near-Field Scatterers Mutually Coupled With an Antenna Array 査読

Takuma Watanabe, Hiroyoshi Yamada

IEEE Transactions on Instrumentation and Measurement   70   1 - 18   2021年

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical and Electronics Engineers ({IEEE})  

DOI： 10.1109/tim.2020.3031368

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Microwave 3D imaging of near-field scatterers mutually coupled with an antenna array 査読

Takuma Watanabe, Hiroyoshi Yamada

IEICE Communications Express   2021年

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electronics, Information and Communications Engineers ({IEICE})  

DOI： 10.1587/comex.2021xbl0157

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Fixed-Point Arithmetic of ℓ2-Norm Approximation for 2-Tuple Arrays with Rotated ℓ2-Norm Evaluation

Yuya Kodama, Shogo Muramatsu, Hiroyoshi Yamada

2020 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference, APSIPA ASC 2020 - Proceedings   1216 - 1221   2020年12月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Institute of Electrical and Electronics Engineers Inc.  

This paper proposes a high-precision fast approximation method for the ℓ2-norm evaluation of 2-tuple arrays by means of a rotated ℓ1-norm evaluation with fixed-point arithmetic. A considerable number of calculations for 2-tuple ℓ2-norm are frequently required in several signal processing applications such as image restoration with isotropic total variation and complex ℓ1-norm regularization. Typical embedded applications prefer parallel processing, constant scaling, and fixed-point arithmetic compared with serial processing, variable multiplication, and floating-point arithmetic. To achieve a hardware-friendly calculation, square and square root operations should be adequately approximated. However, several existing techniques are challenged with respect to approximations with all three preferable features. Thus, in this paper, a hardware-friendly approximation algorithm is proposed. The proposed method uses the fact that the upper bound of the surface of a first-order rotational cone traces a second-order cone, i.e., ℓ2-cone, requests less variable multiplication, and can easily be implemented in parallel with fixed-point arithmetic. To verify the effectiveness of the proposed method, an image restoration performance and software/hardware co-design report are evaluated.

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First demonstration of spectral domain polarimetric decomposition with airborne circular synthetic aperture radar 査読

Takuma Watanabe, Hiroyoshi Yamada, Yasuyuki Oishi

IEICE Communications Express   9 ( 10 )   476 - 481   2020年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electronics, Information and Communications Engineers ({IEICE})  

DOI： 10.1587/comex.2020xbl0091

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Foreword to the Special Issue on the 2019 IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2019)

Akira Hirose, Irena Hajnsek, Akira Iwasaki, Hiroyoshi Yamada

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing   13   6512 - 6514   2020年

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/JSTARS.2020.3038980

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ミリ波FMCWレーダにおける複数パルスを用いた速度折り返し推定について 査読

堀内 貴裕, 山田 寛喜, 山口 芳雄

電子情報通信学会論文誌 B   Vol.J102-B ( No.11 )   873 - 882   2019年11月

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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Khatri-Rao積仮想アレー処理を用いたTomoSARによる三次元イメージング 査読

鈴木 健一郎, 山田 寛喜, 牛腸 正則, 有井 基文, 児島 正一郎, 佐藤 亮一, 山口 芳雄

電子情報通信学会論文誌 B   Vol.102-B ( No.11 )   864 - 872   2019年11月

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

J-GLOBAL

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Successive Stripe Artifact Removal Based on Robust PCA for Millimeter Wave Automotive Radar Imageive Radar Image 査読

Weiwei Shan, Shogo Muramatsu, Hiroyoshi Yamada, Akira Oshima

Proc. of 2019 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   2019年11月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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Indoor Human Tracking with Millimeter-Wave Minimum Redundancy MIMO Radar

Takahiro Horiuchi, Jumpei Konishi, Hiroyoshi Yamada, Shogo Muramatsu

2019 International Symposium on Antennas and Propagation, ISAP 2019 - Proceedings   2019年10月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Institute of Electrical and Electronics Engineers Inc.  

Array radar needs enough array length to realize high angular resolution. However, it takes cost to increase elements physically. Recently, Minimum Redundancy Multiple- Input Multiple-Output (MR-MIMO) was proposed to increase the number of virtual elements efficiently. Further improvements by using Khatri-Rao (KR) transformation in the case of incoherent waves were also proposed. In this paper, we show experimental results on indoor human tracking with millimeter-wave MR- MIMO radar to verify the improvements of resolution and tracking performance in comparison with the results by a conventional MIMO radar.

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Experimental Study on Automotive Millimeter Wave SAR in Curved Tracks

Akira Oshima, Hiroyoshi Yamada, Shogo Muramatsu

2019 International Symposium on Antennas and Propagation, ISAP 2019 - Proceedings   2019年10月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Institute of Electrical and Electronics Engineers Inc.  

Automatic operating system for vehicle has been widely studied. Especially, automotive millimeter-wave (MMW) radar has been attracting attentions. Synthetic Aperture Radar (SAR) processing by using MMW radar can obtain high-resolution 2-D images. In general, SAR processing is used in straight orbits. However, in the case of automobiles, it is necessary to consider not only straight tracks but also curved tracks. In this paper, we show that the performance of automotive MMW-SAR processing on curved tracks by experimental results.

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Review of the comprehensive SAR approach to identify scattering mechanisms of radar backscatter from vegetated terrain 招待 査読

Motofumi Arii, Hiroyoshi Yamada, Shoichiro Kojima, Masato Ohki

Electronics (Switzerland)   8   2019年10月

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© 2019 by the authors. Licensee MDPI, Basel, Switzerland. In a field of polarimetric synthetic aperture radar (SAR) remote sensing, various kinds of polarimetric decomposition techniques have been proposed. However, poor validations prevent them from operational applications. A true composition ratio of scattering mechanisms within a radar backscatter plays a key role. To overcome the issue, a novel comprehensive SAR approach to accurately identify a contribution of each scattering mechanism has been introduced. This is based on multiparametric SAR observation combined with a numerical model simulation. In this article, a comprehensive SAR approach is concisely reviewed to accelerate the research in this field. First, popular model-based polarimetric decompositions are introduced and their limitations are shown. Then, a behavior of scattering mechanisms is analyzed by the discrete scatterer model with some results using real multiparametric SAR data. A comprehensive SAR approach must be essential to realize an operational use of polarimetric SAR data.

DOI： 10.3390/electronics8101098

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Developments of Scattering Power Decomposition From 3 To 7 Components

Yoshio Yamaguchi, Gulab Singh, Kanta Yamada, Maito Umemura, Hiroyoshi Yamada

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium   2019年7月

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掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

DOI： 10.1109/igarss.2019.8900550

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Sensitivity Analysis of Multifrequency MIMP SAR Data From Rice Paddies 査読

Motofumi Arii, Hiroyoshi Yamada, Shoichiro Kojima, Masato Ohki

IEEE Transactions on Geoscience and Remote Sensing   57 ( 6 )   3543   2019年6月

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出版者・発行元：Institute of Electrical and Electronics Engineers ({IEEE})  

DOI： 10.1109/TGRS.2018.2885550

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Retrieval of Polarimetric Azimuthal Angular Characteristics via the Application of Target Decomposition to Spectral Domain Circular SAR Images 査読

Takuma Watanabe, Hiroyoshi Yamada, Yuto Tokutake, Ryoichi Sato, Yoshio Yamaguchi

IEEE Transactions on Geoscience and Remote Sensing   57 ( 5 )   2963   2019年5月

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出版者・発行元：Institute of Electrical and Electronics Engineers ({IEEE})  

DOI： 10.1109/TGRS.2018.2878981

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Polarimetric H/alpha Analysis on Height Direction by Using Polarimetric TomoSAR

Masanori Gocho, Hiroyoshi Yamada, Yoshio Yamaguchi, Ryoichi Sato, Motofumi Arii, Shoichiro Kojima

ISAP 2018 - 2018 International Symposium on Antennas and Propagation   2019年1月

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掲載種別：研究論文（国際会議プロシーディングス）  

In this report, we apply the polarimetric entropy (or H/alpha) analysis to 3-D PolSAR dataset, which are reconstructed by the TomoSAR processing, to clarify the polarimetric scattering characteristic on height direction under the layover phenomenon. The H/alpha analysis, where H and alpha denote entropy and angle calculated by the eigen-decomposition of the polarimetric scattering matrix, is widely used for target decomposition and classification. The entropy increases on multiple scattering process such as under the layover phenomenon and decreases on dominant isolated scattering process, so it can be expected the entropy increases by buildings with layover phenomenon. From the experimental results, we show that the H/alpha analysis on height direction is available, and clarify the change of the entropy compared with the conventional 2-D PolSAR and proposed Pol-TomoSAR analysis.

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