著者

鵜飼 祐生 藤吉 弘亘

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J106-D, no.3, pp.195-206, 2023-03-01

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人物再同定は,異なるカメラで撮影された同一人物の画像を検索するタスクである.人物再同定はその応用上の重要性から注目を集めており,ラベル付けされた大規模データセットを用いて深層学習モデルにより学習することで大きな進展を遂げてきた.また,あるラベル付けされたソースドメインで学習したモデルを他のドメインに適用した場合,推論精度が大きく低下する実用上の課題に対しても,数多くの教師なしドメイン適応手法が提案され,大きく改善されてきた.これらの手法の多くは,Global Average Poolingによる出力のみをもつモデルを用いており,画像特徴の平均的な特性のみを考慮している.そのため,例えばFine-Grainedな問題設定で重要とされる局所的な情報は十分考慮されていない,という課題がある.そこで本論文では,上記の課題を解決するため,Global Average Pooling(GAP)及びGlobal Max Pooling(GMP)により出力される,異なる特性をもつ二つの出力間の違いを考慮しながら,その両方を利用する新たな教師なしドメイン適応手法を提案する.公開された複数の人物再同定を対象とするデータセットにおける実験により,提案手法の人物再同定における教師なしドメイン適応における有効性を確認した.

著者

Keita EMURA Atsushi TAKAYASU

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E106.A, no.3, pp.193-202, 2023-03-01 (Released:2023-03-01)

参考文献数

33

被引用文献数

1

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Identity-based encryption with equality test (IBEET) is a generalization of the traditional identity-based encryption (IBE) and public key searchable encryption, where trapdoors enable users to check whether two ciphertexts of distinct identities are encryptions of the same plaintext. By definition, IBEET cannot achieve indistinguishability security against insiders, i.e., users who have trapdoors. To address this issue, IBEET against insider attacks (IBEETIA) was later introduced as a dual primitive. While all users of IBEETIA are able to check whether two ciphertexts are encryptions of the same plaintext, only users who have tokens are able to encrypt plaintexts. Hence, IBEETIA is able to achieve indistinguishability security. On the other hand, the definition of IBEETIA weakens the notion of IBE due to its encryption inability. Nevertheless, known schemes of IBEETIA made use of rich algebraic structures such as bilinear groups and lattices. In this paper, we propose a generic construction of IBEETIA without resorting to rich algebraic structures. In particular, the only building blocks of the proposed construction are symmetric key encryption and pseudo-random permutations in the standard model. If a symmetric key encryption scheme satisfies CCA security, our proposed IBEETIA scheme also satisfies CCA security.

著者

Haiyan SUN Xingyu WANG Zheng ZHU Jicong ZHAO

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Electronics (ISSN:09168516)

巻号頁・発行日

vol.E106-C, no.3, pp.76-83, 2023-03-01

被引用文献数

1

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In this paper, the spurious modes and quality-factor (Q) values of the one-port dual-mode AlN lamb-wave resonators at 500-1000 MHz were studied by theoretical analysis and experimental verification. Through finite element analysis, we found that optimizing the width of the lateral reflection boundary at both ends of the resonator to reach the quarter wavelength (λ/4), which can improve its spectral purity and shift its resonant frequency. The designed resonators were micro-fabricated by using lithography processes on a 6-inch wafer. The measured results show that the spurious mode can be converted and dissipated, splitting into several longitudinal modes by optimizing the width of the lateral reflection boundary, which are consistent well with the theoretical analysis. Similarly, optimizing the interdigital transducer (IDT) width and number of IDT fingers can also suppress the resonator's spurious modes. In addition, it is found that there is no significant difference in the Qs value for the two modes of the dual-mode resonator with the narrow anchor and full anchor. The acoustic wave leaked from the anchor into the substrate produces a small displacement, and the energy is limited in the resonator. Compared to the resonator with Au IDTs, the resonator with Al IDTs can achieve a higher Q value due to its lower thermo-elastic damping loss. The measured results show the optimized dual-mode lamb-wave resonator can obtain Qs value of 2946.3 and 2881.4 at 730.6 MHz and 859.5 MHz, Qp values of 632.5 and 1407.6, effective electromechanical coupling coefficient (k2eff) of 0.73% and 0.11% respectively, and has excellent spectral purity simultaneously.

著者

吉澤 誠 杉田 典大 湯田 恵美 山家 智之

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:13452827)

巻号頁・発行日

vol.J106-C, no.3, pp.90-98, 2023-03-01

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筆者らは,家庭や職場における簡単な健康管理を目指し,何のセンサも身に着けずに遠隔・非接触的に生体情報を得るための言わば「ウェアレス」なセンシングを実現するための「魔法の鏡」プロジェクトを進めてきた.本論文では,このプロジェクトで開発した,血行状態,自律神経系指標,血圧相関値などの健康関連情報を測定・蓄積・解析するクラウド版「魔法の鏡」と,それをプラットホームとする,体動や照明変動の影響を受けない掌映像脈波計測システム「魔法の球」,及び複数顔同時検出機能のある映像脈波計測システム「魔法の眼」について報告し,その有効性と限界について考察する.

著者

島崎 安徳 西森 健太郎

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 B (ISSN:13444697)

巻号頁・発行日

vol.J105-B, no.7, pp.504-505, 2022-07-01

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0.92/2.4/5GHz帯における様々なセル形態の実伝搬測定データに基づき,複数の伝搬環境に分類した.対数近似曲線にて距離に対する伝搬損失係数を求め,各結果における伝搬損失を考察した.

著者

柴田 拓海 宇都 雅輝

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J106-D, no.1, pp.47-56, 2023-01-01

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近年,受検者の多面的な能力を測定する手段の一つとして小論文試験が注目されている.一方で,小論文試験では,採点にかかる人的・時間的なコストが大きいことが問題となる.この問題を解決する手段の一つとして,自動採点のニーズが高まっている.近年では,深層学習を用いた自動採点手法が多数提案され,高い精度を達成している.そのような深層学習自動採点手法の多くは,各小論文に対して単一の全体得点のみを予測するように設計されている.しかし,主に学習評価場面などで自動採点を活用する場合には,受検者に詳細なフィードバックを与えるために,全体得点だけでなく,複数の評価観点別得点も予測したい場合がある.このようなニーズに対応するため,全体得点に加えて複数評価観点に対応する細目得点も同時に予測できるモデルが近年提案されている.しかし,従来モデルは評価観点固有の複雑なニューラルネットワーク層を有しており,得点予測の根拠について解釈性が低いという問題がある.この問題を解決するために,本研究では,多次元項目反応理論を用いて予測根拠の解釈性を高めた複数観点同時自動採点モデルを提案する.

著者

Akito IGUCHI Yasuhide TSUJI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Electronics (ISSN:09168516)

巻号頁・発行日

vol.E105-C, no.11, pp.644-651, 2022-11-01

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This paper shows structural optimal design of optical waveguide components utilizing an efficient 3D frequency-domain and 2D time-domain beam propagation method (BPM) with an alternating direction implicit (ADI) scheme. Usual optimal design procedure is based on iteration of numerical simulation, and total computational cost of the optimal design mainly depends on the efficiency of numerical analysis method. Since the system matrices are tridiagonal in the ADI-based BPM, efficient analysis and optimal design are available. Shape and topology optimal design shown in this paper is based on optimization of density distribution and sensitivity analysis to the density parameters. Computational methods of the sensitivity are shown in the case of using the 3D semi-vectorial and 2D time-domain BPM based on ADI scheme. The validity of this design approach is shown by design of optical waveguide components: mode converters, and a polarization beam splitter.

著者

池川 航史 西島 直

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J105-D, no.11, pp.653-656, 2022-11-01

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本論文における提案手法は,機密データを外部に出すことなく他の組織に利活用させることを可能とする.また,提案手法は秘匿機能をもつスマートコントラクトを活用し,機密データ利活用時の手続き情報に関しても秘匿化を実現する.

著者

Kazuhito MATSUDA Kouji KURIHARA Kentaro KAWAKAMI Masafumi YAMAZAKI Fuyuka YAMADA Tsuguchika TABARU Ken YOKOYAMA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E105.D, no.12, pp.2032-2039, 2022-12-01 (Released:2022-12-01)

参考文献数

13

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Statical causal discovery is an approach to infer the causal relationship between observed variables whose causalities are not revealed. LiNGAM (Linear Non-Gaussian Acyclic Model), an algorithm for causal discovery, can calculate the causal relationship uniquely if the independent components of variables are assumed to be non-Gaussian. However, use-cases of LiNGAM are limited because of its O(d3x) computational complexity, where dx is the number of variables. This paper shows two approaches to accelerate LiNGAM causal discovery: SIMD utilization for LiNGAM's mathematical matrixes operations and MPI parallelization. We evaluate the implementation with the supercomputer Fugaku. Using 96 nodes of Fugaku, our improved version can achieve 17,531 times faster than the original OSS implementation (completed in 17.7 hours).

著者

Gyeongjin RA Su-hyun KIM Imyeong LEE

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E105-D, no.11, pp.1857-1871, 2022-11-01

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Recently, the adoption of the industrial Internet of things (IIoT) has optimized many industrial sectors and promoted industry “smartization.” Smart factories and smart industries connect the real and virtual worlds through cyber-physical systems (CPS). However, these linkages will increase the cyber security danger surface to new levels, putting millions of dollars' worth of assets at risk if communications in big network systems like IIoT settings are left unsecured. To solve these problems, the fundamental method is security, such as authentication and confidentiality, and it should require the encryption key. However, it is challenging the security performance with the limited performance of the sensor. Blockchain-based identity management is emerging for lightweight, integrity and persistence. However, the key generation and management issues of blockchain face the same security performance issues. First, through blockchain smart contracts and hierarchical deterministic (HD) wallets, hierarchical key derivation efficiently distributes and manages keys by line and group in the IIoT environment. Second, the pairing verification value based on an elliptic curve single point called Root Signature performs efficient public key certificate registration and verification and improves the key storage space. Third, the identity log recorded through the blockchain is the global transparency of the key lifecycle, providing system reliability from various security attacks. Keyless Signature Infrastructure (KSI) is adopted to perform efficiently via hash-based scheme (hash calendar, hash tree etc.). We analyze our framework compared to hash-based state commitment methods. Accordingly, our method achieves a calculation efficiency of O(nlog N) and a storage space saving of 60% compared to the existing schemes.

著者

三宅 悠介 峯 恒憲

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J105-D, no.11, pp.641-652, 2022-11-01

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ECサイトで扱う商品種類増大に伴う情報過多問題を解決するため,効果的な推薦手法を選択することが重要である.推薦手法の有効性は様々な要因や時間の経過によって左右されるため,最適な推薦手法の選択には実環境での継続的な評価が不可欠である.しかしながら,実環境での評価では機会損失が課題となる.本研究では,この実環境での評価を,文脈と時間の経過を考慮した多腕バンディット問題とみなして解くことで,機会損失を抑えながら最適な推薦手法を自動かつ継続的に選択するメタ推薦システムを提案する.評価では,実際のECサイトから取得したデータを用いて最適な推薦手法を選択するシミュレーションを実施した.実験の結果,提案システムが,評価時に生じる機会損失を抑え,文脈と時間の経過を考慮しない場合と比較して累積クリック数を約9.7%増加させる効果があることを確認した.

著者

Takehiro KITAMURA Mahfuzul ISLAM Takashi HISAKADO Osami WADA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E105-A, no.11, pp.1450-1457, 2022-11-01

被引用文献数

3

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High-speed flash ADCs are useful in high-speed applications such as communication receivers. Due to offset voltage variation in the sub-micron processes, the power consumption and the area increase significantly to suppress variation. As an alternative to suppressing the variation, we have developed a flash ADC architecture that selects the comparators based on offset voltage ranking for reference generation. Specifically, with the order statistics as a basis, our method selects the minimum number of comparators to obtain equally spaced reference values. Because the proposed ADC utilizes offset voltages as references, no resistor ladder is required. We also developed a time-domain sorting mechanism for the offset voltages to achieve on-chip comparator selection. We first perform a detailed analysis of the order statistics based selection method and then design a 4-bit ADC in a commercial 65-nm process and perform transistor-level simulation. When using 127 comparators, INLs of 20 virtual chips are in the range of -0.34LSB/+0.29LSB to -0.83LSB/+0.74LSB, and DNLs are in the range of -0.33LSB/+0.24LSB to -0.77LSB/+1.18LSB at 1-GS/s operation. Our ADC achieves the SNDR of 20.9dB at Nyquist-frequency input and the power consumption of 0.84mW.

著者

Thi Thu Thao KHONG Takashi NAKADA Yasuhiko NAKASHIMA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E105.D, no.7, pp.1308-1319, 2022-07-01 (Released:2022-07-01)

参考文献数

38

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We introduce a hybrid Bayesian-convolutional neural network (hyBCNN) for improving the robustness against adversarial attacks and decreasing the computation time in the Bayesian inference phase. Our hyBCNN models are built from a part of BNN and CNN. Based on pre-trained CNNs, we only replace convolutional layers and activation function of the initial stage of CNNs with our Bayesian convolutional (BC) and Bayesian activation (BA) layers as a term of transfer learning. We keep the remainder of CNNs unchanged. We adopt the Bayes without Bayesian Learning (BwoBL) algorithm for hyBCNN networks to execute Bayesian inference towards adversarial robustness. Our proposal outperforms adversarial training and robust activation function, which are currently the outstanding defense methods of CNNs in the resistance to adversarial attacks such as PGD and C&W. Moreover, the proposed architecture with BwoBL can easily integrate into any pre-trained CNN, especially in scaling networks, e.g., ResNet and EfficientNet, with better performance on large-scale datasets. In particular, under l∞ norm PGD attack of pixel perturbation ε=4/255 with 100 iterations on ImageNet, our best hyBCNN EfficientNet reaches 93.92% top-5 accuracy without additional training.

著者

Kei FUJIMOTO Masashi KANEKO Kenichi MATSUI Masayuki AKUTSU

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Communications (ISSN:09168516)

巻号頁・発行日

vol.E105-B, no.5, pp.522-532, 2022-05-01

被引用文献数

4

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Packet processing on commodity hardware is a cost-efficient and flexible alternative to specialized networking hardware. However, virtualizing dedicated networking hardware as a virtual machine (VM) or a container on a commodity server results in performance problems, such as longer latency and lower throughput. This paper focuses on obtaining a low-latency networking system in a VM and a container. We reveal mechanisms that cause millisecond-scale networking delays in a VM through a series of experiments. To eliminate such delays, we design and implement a low-latency networking system, kernel busy poll (KBP), which achieves three goals: (1) microsecond-scale tail delays and higher throughput than conventional solutions are achieved in a VM and a container; (2) application customization is not required, so applications can use the POSIX sockets application program interface; and (3) KBP software does not need to be developed for every Linux kernel security update. KBP can be applied to both a VM configuration and a container configuration. Evaluation results indicate that KBP achieves microsecond-scale tail delays in both a VM and a container. In the VM configuration, KBP reduces maximum round-trip latency by more than 98% and increases the throughput by up to three times compared with existing NAPI and Open vSwitch with the Data Plane Development Kit (OvS-DPDK). In the container configuration, KBP reduces maximum round-trip latency by 21% to 96% and increases the throughput by up to 1.28 times compared with NAPI.

著者

Marimo MATSUMOTO Masaya TAMURA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Electronics (ISSN:09168516)

巻号頁・発行日

vol.E105-C, no.9, pp.398-406, 2022-09-01

被引用文献数

2

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Couplers in a film-type capacitive wireless power charging (CWC) system for an implantable medical device were designed and analyzed in this work. Due to the high conductivity of the human body, two paths contribute to the power transmission, namely a high-frequency current and an electric field. This was confirmed by an equivalent circuit of the system. During analysis of the system, we used pig skin with subcutaneous fat, which has a high affinity with the human body, to search for a highly efficient electrode shape. Subsequently, we fabricated the designed coupler and measured ηmax. An ηmax of 56.6% was obtained for a half-circular coupler with a radius of 20 mm and a distance of 10 mm between adjacent couplers. This study will contribute to the realization of implantable devices that can be recharged during breaks or while sleeping at home and is expected to significantly reduce the burden on patients.

著者

間邊 哲也 鮒谷 知也

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 A (ISSN:09135707)

巻号頁・発行日

vol.J105-A, no.8, pp.96-105, 2022-08-01

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本論文では,スマートウォッチを含む歩行者ナビゲーションシステムにおいて,案内性能と安全性の両観点で比較評価実験を行う.まず,スマートウォッチで提示する案内情報の異なる3種類の評価用システムを構築する.次に,スマートウォッチの有無による歩行者ナビゲーションシステムの評価実験を行い,歩行者ナビゲーションシステムを利用するユーザの多くが必要とする通知,推奨方向,補足情報のみをスマートウォッチで提示することで,案内性能と安全性が両立できる可能性を示す.最後に,画面表示を含むスマートウォッチによる歩行者ナビゲーションシステムの評価実験を行い,スマートウォッチに多くの案内情報を提示すると,安全性だけでなく,案内性能も低下することを示す.以上のことから,スマートウォッチを含む歩行者ナビゲーションシステムにおいて案内性能と安全性を両立するためには,ユーザにとって真に必要な情報(分岐点での通知,推奨方向,補足情報)のみに限定して提示することが重要な要件の一つであることを明らかにする.

著者

山本 康平 尾﨑 龍之介 日景 隆 山﨑 圭子 宮下 ちひろ 岸 玲子

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 B (ISSN:13444697)

巻号頁・発行日

vol.J105-B, no.8, pp.640-642, 2022-08-01

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青少年の電波ばく露と健康影響に関する大規模な疫学研究が実施されている.本論文では,同疫学研究のばく露量推定に用いられる携帯型個人ばく露計について,被験者に近接配置された際に人体による反射及び遮蔽影響が受信特性に与える影響を定量的に評価した.

著者

熊木 武志 下村 優太郎

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J105-D, no.8, pp.499-503, 2022-08-01

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本研究は,近年大きな社会問題となっている,スマートフォンを用いた盗撮行為に対して,新しい抑止技術を提案するものである.具体的には,LED照明を利用して,CMOSイメージセンサで撮影された動画に対し,ムービースタンプと呼ぶフリッカを埋め込み,画質を劣化させる.それとともに,このスタンプから動画が撮影された日時や場所等の情報を抽出することで,盗撮行為の抑止につなげる.更には,盗撮動画がインターネットにアップロードされる2次被害も抑えることが可能となる.一般にフリッカは,ノイズとみなされ,いかに低減するかが重要であったが,本研究はこれを積極的に活用することで,社会問題の解決へとつなげる,他に類を見ない技術である.

著者

Haipeng Fu Yipeng Mu Xin Zhang

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

vol.19, no.14, pp.20220241, 2022-07-25 (Released:2022-07-25)

参考文献数

32

被引用文献数

2

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A 2.58THz detector based on plasma-wave theory proposed by Dyakonov and Shur was designed and fabricated in 55nm standard CMOS process. Each detector consists of a filter patch antenna and a metal-oxide-semiconductor field-effect-transistor (MOSFET). We design a filter antenna to receive the terahertz signal, and the output of detector is extracted by a phase-locked amplifier. The antenna generates filtering function by adding two pairs of branches to the feeding lines. The frequency selection function of high spectral resolution detector proposed in this paper is mainly realized by filtering antenna. According to the test results and HFSS simulation results, the proposed filter antenna is feasible. The detector can achieve a room-temperature maximum responsivity (RV) of 67.2V/W. Our results show that CMOS terahertz detectors have potential applications in the imaging field.

著者

Akihiro YOSHITAKE Masaharu TAKAHASHI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Communications (ISSN:09168516)

巻号頁・発行日

vol.E105-B, no.7, pp.848-855, 2022-07-01

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Currently, wireless power transmission technology is being developed for capsule endoscopes. By removing the battery, the capsule endoscope is miniaturized, the number of images that can be taken increases, and the risk of harmful substances leaking from the battery when it is damaged inside the body is avoided. Furthermore, diagnostic accuracy is improved by adjusting the directivity of radio waves according to the position of the capsule endoscope to improve efficiency and adjusting the number of images to be taken according to position by real-time position estimation. In this study, we report the result of position estimation in a high-definition numerical human body model and in an experiment on an electromagnetic phantom.