担当区分：責任著者   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）

As the marine business expands, there is a growing demand for real-time capturing of autonomous underwater vehicles (AUVs) status using radio frequency communications. On the other hand, electromagnetic noise emitted by AUVs can interfere with communications.To investigate the impact of electromagnetic noise in undersea Wavelet-OFDM communication, the author constructed an experimental setup that simulates the radio wave transmission characteristics of underwater antennas without the experimental environment in the sea and introduced external noise to assess communication speed. The authors compared the noise power induced in the receiver to the communication speed using the proposed evaluation setup.
The results shows that when the distance between the loop antennas was 1 m, communication was disabled by applying a -90 dBm disturbance. Additionally, the author proposed a method to estimate communication speed using transmission characteristics and measured electromagnetic noise. The communication speeds calculated using the proposed method agreed with the measured results with a maximum error of 1.65 Mbps. Improving accuracy remains a challenge for future research.

DOI： 10.34385/proc.82.thuam1a.4

CiNii Research

担当区分：最終著者   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）

The impedance balance method is used as a countermeasure against electromagnetic noise in power electronic circuits. In a previous study, the impedance balance method was used to reduce the common-mode voltage in a three-phase inverter circuit. However, it has been difficult to reduce common-mode voltage using conventional methods in an electric compressor system with an integrated mechanical and electrical structure, where the three-phase inverter and motor are housed in a single housing. This research describes a method to reduce the common-mode voltage in an electric compressor system with an integrated mechanical and electrical structure, using an impedance balance method. The first is to reduce the impedance of the balancing elements added to the circuit, and the second is to increase the impedance of the three three-phase output line connecting the three-phase inverter and the motor. By combining these two methods, the frequency bandwidth of the reduction effect was expanded from 2 MHz to 30 MHz, and a reduction in common-mode voltage of up to 30 dB was confirmed.

DOI： 10.34385/proc.82.monpm2c.2

CiNii Research

担当区分：最終著者   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）

In this report, the mechanism of mode conversion of interfering electromagnetic waves injected into communication equipment from coaxial cables to in-vehicle communication modules is evaluated and clarified from the viewpoint of immunity.A mode conversion equivalent circuit was used for this purpose.
Considering radiated immunity, the applied electromagnetic field induces a common-mode current in the coaxial cable, which propagates through the cable to the signal line inside the enclosure via a connector.
When microstrip lines are used within a printed circuit board, the imbalance difference between the two transmission lines causes a conversion from common-mode current to normal-mode voltage.
Furthermore, when the imbalance difference is small, the parasitic inductance between the ground connections at the connectors is dominant in the mode conversion.
To evaluate these phenomena, a mode transformation circuit with ideal transformers was created.
The circuit simulations were conducted using the model and a modal transmission line.
The obtained results showed the same trend as that of the 3D electromagnetic field simulation.

DOI： 10.34385/proc.82.wedpm1a.1

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The manuscript introduces a radio wave-based wireless communication system tailored for Autonomous Underwater Vehicles (AUVs), optimized for underwater deployment. Initial experiments to ascertain the fundamental properties of a loop antenna were conducted in a small-scale water tank, followed by comprehensive communication and video transmission trials in a larger tank with an AUV. A specialized waterproof enclosure was developed to house a waterproof antenna, a Vector Network Analyzer (VNA), and a communication board. This setup facilitated the evaluation of the loop antenna's radio propagation attributes and the identification of frequencies conducive to underwater communication. Designed with practical deployment in mind, the system incorporates a 2-meter loop antenna for signal transmission and a 0.5m by 0.8m rectangular loop antenna integrated into the AUV for signal reception. Utilizing a wavelet Orthogonal Frequency Division Multiplexing (OFDM) communication board and tuning to lower frequencies, the system successfully established User Datagram Protocol (UDP) and Transfer Control Protocol (TCP) communications within a few meter radius from the transmitting antenna, achieving data transfer rates up to 6.8 Mbps.

DOI： 10.1109/ACCESS.2024.3457508

Scopus

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担当区分：最終著者   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）

Kyushu Institute of Technology (Kyutech) is developing a 6U CubeSat that is named 'VERTECS' (Visible Extragalactic background RadiaTion Exploration by CubeSat). This is an astronomical CubeSat designed to reveal star formation history by observing visible extragalactic background light [1] and the first satellite for Kyutech to rely on not UHF (around 400 MHz) but only microwave (>1 GHz) to communicate between the satellite and ground station. Microstrip patch antennas are adopted on this CubeSat due to desired characteristics such as low profile, lightweight, and non-deployable structure. However due to the performance of the microstrip patch antenna is limited such as directional radiation pattern and narrow operational bandwidth, the placement of the antenna on CubeSat is more critical compared to that of the conventional antenna for UHF communication, such as dipole and monopole antenna. In this paper, we describe choosing the antenna placement while considering antenna performance, including the coupling of transmission and reception antenna.

DOI： 10.23919/ICEP61562.2024.10535673

Scopus

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担当区分：責任著者   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）

A matching circuit is required to improve the transmission characteristics of an antenna for undersea radio communication. Even if the reflection coefficient, S11, the transmission characteristics will not necessarily improve in a system with high radio-wave attenuation in the sea. Therefore, the authors designed a matching circuit to maximize transmission efficiency in the frequency band used. However, it is necessary to acquire the transmission characteristics between the antennas through experiment or simulation for circuit design. In the proposed circuit, an N-section LC ladder circuit is used. When the proposed matching circuits are connected to the antenna, the transmission coefficient is improved up to 12 dB.

DOI： 10.23919/ICEP61562.2024.10535535

Scopus

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担当区分：最終著者   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）

The transmission line constructed with cable and ground plane is one of the radiated emission sources. Therefore, the characteristics of the line should be investigated to achieve electromagnetic compatibility. The numerical analysis has the merit that the characteristics can be investigated effectively, but the perfect modeling of this transmission line is difficult. In this paper, we evaluated the calculation accuracy from 0.1 MHz to 1000 MHz by comparing the calculating line constants with the measuring values. As a result, it was found that the characteristic impedance and phase constant can be calculated with a certain degree of accuracy, but the deviation of the attenuation constant is large.

Scopus

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担当区分：責任著者   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）

The authors' research group is engaged in research and development of undersea radio communication technology. To improve communication efficiency, antenna characteristic and communication system are being developed through actual measurement. However, it is not easy to conduct large-scale measurement because of the time and cost required for preparation. Therefore, an undersea communication emulator that simulates undersea radio wave attenuation is being built to simplify large-scale experiment. In this paper, an undersea communication emulator of the transmission characteristic obtained by actual measurement is fabricated, and comparison of transmission characteristic and communication performance are shown through communication experiment. As a result of evaluating the communication characteristics of the fabricated emulator, it was confirmed that the transmission characteristic was expressed with a difference of less than 1 dB in a bandwidth of approximately 85 % of the carrier frequency, and that the transmission rate could be simulated with an accuracy of less than 1 Mbps.

Scopus

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担当区分：責任著者   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）

In this paper, we compared the immunity characteristics of wiring harnesses connecting automotive communication equipment at different wiring lengths. The communication behavior of an automotive harness connected to an evaluation module equipped with automotive Ethernet and exposed to radiated electromagnetic noise was compared for different wiring lengths. The S-parameters were measured under the same wiring conditions, and the frequency characteristics of the amount of noise applied were derived and compared with the length of the wiring. A reverberation chamber was used for the evaluation. From the results of each evaluation, changes in immunity characteristics due to differences in wiring length were confirmed for each frequency of electromagnetic waves, but no correlation was observed between communication quality characteristics and the results of S-parameter measurement. On the other hand, the frequency characteristics of the amount of noise applied also changed with the difference in wiring length, suggesting that a stable evaluation is possible with longer wiring lengths.

Scopus

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担当区分：責任著者   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）

As the marine business expands, there is a growing demand for real-time capturing of autonomous underwater vehicles (AUVs) status using radio frequency communications. On the other hand, electromagnetic noise emitted by AUVs can interfere with communications. To investigate the impact of electromagnetic noise in undersea Wavelet-OFDM communication, the author constructed an experimental setup that simulates the radio wave transmission characteristics of underwater antennas without the experimental environment in the sea and introduced external noise to assess communication speed. The authors compared the noise power induced in the receiver to the communication speed using the proposed evaluation setup. The results shows that when the distance between the loop antennas was 1 m, communication was disabled by applying a -90 dBm disturbance. Additionally, the author proposed a method to estimate communication speed using transmission characteristics and measured electromagnetic noise. The communication speeds calculated using the proposed method agreed with the measured results with a maximum error of 1.65 Mbps. Improving accuracy remains a challenge for future research.

Scopus

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担当区分：責任著者   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）

The impedance balance method is used as a countermeasure against electromagnetic noise in power electronic circuits. In a previous research, the authors' research group confirmed the reduction of common-mode voltage in a three-phase inverter circuit using the impedance balance method. However, it has been difficult to reduce common-mode voltage using conventional methods in an electric compressor system with an integrated mechanical and electrical structure, where the three-phase inverter and motor are housed in a single housing. This research describes a method to reduce the common-mode voltage in an electric compressor system with an integrated mechanical and electrical structure, using an impedance balance method. The first is to reduce the impedance of the balancing elements added to the circuit, and the second is to increase the impedance of the three three-phase output line connecting the three-phase inverter and the motor. By combining these two methods, the frequency bandwidth of the reduction effect was expanded from 2 MHz to 30 MHz, and a reduction in common-mode voltage of up to 30 dB was confirmed.

Scopus

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担当区分：最終著者   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）

In this report, the mechanism of mode conversion of interfering electromagnetic waves injected into communication equipment from coaxial cables to in-vehicle communication modules is evaluated and clarified from the viewpoint of immunity. A mode conversion equivalent circuit was used for this purpose. Considering radiated immunity, the applied electromagnetic field induces a common-mode current in the coaxial cable, which propagates through the cable to the signal line inside the enclosure via a connector. When microstrip lines are used within a printed circuit board, the imbalance difference between the two transmission lines causes a conversion from common-mode current to normal-mode voltage. Furthermore, when the imbalance difference is small, the parasitic inductance between the ground connections at the connectors is dominant in the mode conversion. To evaluate these phenomena, a mode transformation circuit with ideal transformers was created. The circuit simulations were conducted using the model and a modal transmission line. The obtained results showed the same trend as that of the 3D electromagnetic field simulation.

Scopus

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担当区分：責任著者   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）

The Autonomous Underwater Vehicle (AUV) is anticipated as a means of collecting underwater visual information using its built-in camera. While underwater radio wave communication via underwater antennas has been developed as a means of information collection, it is expected that the metal casing of AUV may adversely affect the transmission characteristics of antennas in underwater radio wave communication. Therefore, this report evaluates the impact of AUV's metal casing on antenna-to-antenna communication using an electromagnetic field simulator. The evaluation indicates that when the size of the antennas is larger than the AUV's metal casing, the impact on transmission characteristics is minimal even when the AUV is positioned between the antennas. On the other hand, when the metal casing is larger than the antenna size, the transmission characteristics between antennas degrade due to eddy currents flowing in the metal casing induced by antenna currents. Consequently, it is suggested that when attaching underwater antennas to AUVs, maintaining relatively good transmission characteristics, even with smaller antennas, is possible by appropriately configuring the size relationship and placement of the metal casing relative to the antennas.

Scopus

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担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

差動信号のインタフェースは多くの車載機器に使用されており，コモンモードフィルタ（CMF: Common Mode Filter）がキーデバイスとして使用される．CMFの特性指標としてミクスドモード・Sパラメータが使用され，デファレンシャルモード(DM)である信号がCMFの不均衡によりコモンモード(CM)に変換され放射エミッションに大きく寄与する．ミクスドモード・Sパラメータはそれぞれに位相特性が含まれており，元々発生するCM信号の位相とモード変換によって生じたCM信号の位相は同じではなく，単純に比較できない．そのためCMFの選択においても従来システムとして組み込んでCISPR25に準拠した形で比較評価を行う必要がある．本研究においては，CMFの有用性を確認する方法の一つとして等価コモンモード電圧 VEQ の計算式を求め，あるDM信号源とCM信号源の矩形波に対してそれぞれのCMFの VEQ を算出した．次に，信号源の条件が同じ波形を用いて36 MHzから196 MHzまでの放射エミッションレベルをCISPR25に準拠した測定により評価した．その結果，等価コモンモード電圧 VEQ と大小関係が同じ傾向だったことがわかった．

DOI： 10.14923/transcomj.2022pep0009

CiNii Research

担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

今日，IoT化の需要増に伴い，工場等の大規模施設での高速電力線通信(PLC)の要望が高まっている．これまで，一般家庭における単相電力線における伝送特性等の研究は多く行われてきたが，大規模施設における分電盤を経由するPLC信号の透過特性に分岐数やブレーカーの構造が与える影響，及び異相間通信を含む透過特性は明らかにされていない．そこで，本論文では，工場等の大規模施設で利用される分電盤を経由する透過特性について，まずブレーカー単体における信号伝搬特性を検討し，漏電ブレーカーのキャパシタの影響により通常ブレーカーに比べてミクスドモードSパラメータ値が大きくなることを示した．そして，分電盤を経由する通信において分岐数がどのように影響するかを測定と解析により検討し，いずれの場合でもおおよそ分岐数分の1に近くなることを示した．本論文により分電盤を経由した透過特性を概算することで，PLCの中継器を設置すべき場所を推定することが可能となる．

DOI： 10.14923/transcomj.2022pep0001

CiNii Research

担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.11486/ejisso.37.0_14a5-4

CiNii Research

担当区分：最終著者   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）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Radiofrequency (RF) communication provides a high data rate. However, electromagnetic wave is seriously limited by high attenuation in the water medium. In this study, we investigate Radiofrequency communication in seawater. The experiment results show the effects of the distance between the transmitter and receiver, and the stability of the antennas. We achieved HD video transmission with 25fps.

DOI： 10.5954/icarob.2023.os21-1

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Acoustics communication and wireless optical communication have limitations of low latency and water conditions effects respectively. Radiofrequency (RF) communication provides a high data rate with free orientation of the transmitter/receiver antennas. However, electromagnetic waves are highly restricted by high attenuation over short distances in the underwater medium. In this study, we investigated the RF communication in a tank full of seawater. A loop antenna and rectangular antenna were used for the base station and AUV respectively. The experiments were conducted to measure the transmission rate with different distances between the base station and the AUV using both User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). Live video streaming with framerate analysis was considered. The results show the effect of the distance between the transmitter and receiver on the transmission rate, in addition, to the antenna's stability has huge effects on the connection stability. We successfully achieved a High-Definition (HD) video streaming with 25fps for over 1 meter.

DOI： 10.57417/jrnal.10.1_84

Scopus

CiNii Research

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担当区分：責任著者   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）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Radiofrequency (RF) communication provides a high data rate. However, electromagnetic wave is seriously limited by high attenuation in the water medium. In this study, we investigate Radiofrequency communication in seawater. The experiment results show the effects of the distance between the transmitter and receiver, and the stability of the antennas. We achieved HD video transmission with 25fps.

Scopus

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担当区分：責任著者   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）

AUVs are used for marine resource exploration, and although acoustic, laser, etc., are often used for wireless communication for AUVs, wireless communication using RF signals is being studied. By placing the VNA in a waterproof container, we measured the insertion loss between the antennas under seawater and obtained good results with simulation results. Furthermore, using a Wavelet-OFDM module as the communication method, a maximum communication speed of 6.8 Mbps was achieved with the antennas embedded in the AUV immersed in seawater.

DOI： 10.23919/EuCAP57121.2023.10133725

Scopus

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担当区分：最終著者   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）

Common-mode filter (CMF) is a vital device to improve electromagnetic compatibility (EMC), and the analysis of the CMF effect is essential to improve the design quality of EMC. This paper analyzes the suppression effect of CMF used for telecommunication lines using a chain parameter matrix. The chain parameter matrix represented the CMF and the interface cable, and the S21 at the far end of the cable was calculated. The analytical method was validated by comparing measurements using unshielded twisted pair (UTP) and shielded twisted pair (STP) cables. The results showed that the analysis method was appropriate for analyzing the suppression effect. Using the analysis method, the suppression effect was evaluated by the common mode (CM) current at the cable input and the radiated electric field. The result showed that the characteristic impedance and the transmission loss of the CM transmission line affect the suppression effect. The result also showed that the suppression effect by the radiated electric field could be estimated from the suppression effect by the CM current at the cable input.

DOI： 10.1109/EMCSIPI50001.2023.10241556

Scopus

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担当区分：最終著者   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）

It is known that power line communication (PLC) works across different phases in a three-wire three-phase distribution system; even through the pairs of lines for each phase are not physically connected. This research focuses on the distribution boards in the power distribution network and evaluates the effect on PLC of an earth leakage circuit breaker(ELCB) attached to the boards. The results of an evaluation of the common-mode current with and without the ELCB showed that it increased with the ELCB. Resonance in our setup occured at 20 MHz. A simulation analysis showed that the capacitor connecting the two wires at both ends of the ELCB contributed to the resonance.

DOI： 10.1109/EMCEurope57790.2023.10274371

Scopus

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担当区分：最終著者   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）

The impedance-balancing method is a way of reducing common-mode voltage. However, when it is applied to a three-phase inverter circuit, the inductances of the two conductor lines supplying the power affect the common-mode voltage. Here, we investigated the effect of the inductance of the conductor lines supplying power on the common-mode voltage in the impedance balancing method by using a circuit simulation. The results show that when the balance of the inductances of the two conductor lines changes, the value of the balancing element that reduces the common-mode voltage also changes. An analysis of the common-mode voltage during individual switching of the insulated-gate bipolar transistors constituting the three-phase inverter shows that it is reduced under all switching conditions.

DOI： 10.1109/EMCEurope57790.2023.10274203

Scopus

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担当区分：責任著者   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）

With angle of incidence, The authors evaluated how the variation of transmission attenuation to glass for radio waves in the 28 GHz band used in 5G communication. As a result, we observed that the transmission attenuation tends to decrease as the angle of incidence increases for horizontal magnetic field polarization to the glass. In contrast, for horizontal electric field polarization to the glass, the transmission attenuation tends to increase as the angle of incidence increases. Additionally, we observed the variation of transmission attenuation with angle of incidence was different, even for samples with close transmission attenuation at the frontal angle. A variation of approximately 1.7 dB in transmission attenuation was observed within the range of 0 to 45 degrees for both horizontal magnetic field polarization and horizontal electric field polarization, in all samples except for Low-E Glass. Furthermore, the range of variation in transmission attenuation with angle of incidence was shown to be broad, comparable to the minimum transmission attenuation observed for each sample. In the case of Low-E Glass, approximately 8 dB variation was observed within measured range. These results highlight the importance of considering more detailed sample characteristics and varying angle of incidence when evaluating and designing radio wave propagation paths.

DOI： 10.1109/APMC57107.2023.10439778

Scopus

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担当区分：最終著者,　責任著者   記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）

DOI： 10.5104/jiep.25.309

Scopus

CiNii Research

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The use of PLC (power line communication) is growing as the adoption of IoT technology becomes more widespread. However, the maximum communication distance between PLC modems cannot yet be clearly defined since the communication characteristics of the power lines used for PLC are not formally specified. In this paper, the propagation characteristics in the high-speed PLC communication band of 2–30 MHz were investigated when equipment is not connected to the power line except both ends. The line constants for five typical types of cables used as single-phase and two-wire power lines were measured. Our results showed that different cables have markedly different transmission characteristics. The attenuation constant varied up to fourfold depending on the cable insulator material. We also derived a method of estimating the communication distance for different cables for application of the HD-PLC system, which is the most commonly used type of high-speed PLC. The measurement result by using VCT cable was almost agreed with the estimated value. By comparing the estimated distance with the experimental results, we show that the transmission distance can be estimated with sufficient accuracy for practical use. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

DOI： 10.1002/tee.23535

Scopus

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担当区分：責任著者   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）

RF interference is a vital issue to construct the communication network using many Internet of Things (IoT) devices. This study proposes the rapid estimation three-dimensional communication range for the wireless communication system using magnetic field coupling of air-core coils in HF broadband communication. Firstly, an equivalent circuit for rapid calculation of transmission coefficient between transmission coils is shown. The theoretical equation for accurate calculation of the inductance of a straight conductor is derived, followed by the calculation of the total inductance of coils by combining inductances of straight conductors. Then, the calculation speed and accuracy of the proposed method are verified by the simulation and the measurement using the coil implemented on a printed circuit board (PCB). As a result, the proposed method can calculate the transmission coefficient in a few milliseconds, and the error is approximately 1 dB compared to the measurement results. Additionally, it plotted the entire communication range in 3 seconds for the case study of a 2-turns coil.

DOI： 10.1109/EMCSI39492.2022.9889342

Scopus

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担当区分：最終著者   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）

EMI testing of in-vehicle equipment must be conducted during the automotive development phase. ICs used in automotive equipment need to be replaced by ICs with stable supply due to the shortage of semiconductors. However, it is inefficient to perform EMI testing for every change. Therefore, we are researching a mechanism to complete the evaluation of radiated noise generated from wire harnesses connected to in-vehicle electronic devices with a single IC. We examined and compared the results of two EMI testing methods. One is radiated emission measurement from a wire harness with equipment, while the other is the conducted emission measurement of an IC. The radiated emissions from the wiring harnesses connected to the vehicle-mounted equipment were measured in accordance with CISPR 25 (ALSE). On the other hand, the measurement of conducted emissions from a stand-alone vehicle-mounted IC complies with IEC 61967-4. As a result, it was confirmed that ICs that performed lower noise in stand-alone IC measurements also performed lower noise in mounted in-vehicle equipment. The results show that there is a relationship between the radiated noise from the wiring harness and the conducted noise generated by the individual vehicle-mounted ICs.

DOI： 10.1109/ICSJ55786.2022.10034693

Scopus

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担当区分：最終著者   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）

An immediate response is desired when any failure on overhead power distribution systems has occurred, and the TDR(Time Domain Reflecting) method has been introduced to detect fault detection locations. However, accurate detection of the fault point is difficult due to waveform distortion and decrease in amplitude of TDR pulse in complex networks with multiple branches and electric power distribution equipment such as transformers and switchgear. A method for detecting fault points from TDR waveforms using deep learning is proposed in this study. The proposed method can be applied to detect fault locations and fault types in branching power distribution networks where multiple reflected waves are observed. Since the deep learning algorithm requires a large amount of waveform data, we developed a fast simulation method to create the data. To simulate the circuit rapidly, the power distribution line was treated as a transmission line, thereby deriving the fundamental matrix of the transmission line. Additionally, the equivalent circuit model of the power distribution network was represented by cascading the fundamental matrix. The TDR waveform data was obtained rapidly by calculating the equivalent circuit using MATLAB. We used this to create many TDR waveform data of an overhead distribution network model with multiple branches and performed fault locations detection using a deep learning algorithm. As a result, it was shown that the location of accident was identified with 96.8% accuracy.

DOI： 10.1109/EMCEurope51680.2022.9901205

Scopus

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担当区分：最終著者   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）

This paper investigates common mode generation in a wideband communication system using magnetic field coupling with two coils. Two coils are placed in parallel and communicate without resonance in the frequency band below 100 MHz. In this case, the common mode current to the feeder line may cause the transmission of electromagnetic field beyond the designed communication range. The circuit analysis shows that both magnetic and electric field coupling contribute to the common mode generation. It was also suggested that the phase difference between these couplings may cancel the common mode generation.

DOI： 10.1109/APEMC53576.2022.9888658

Scopus

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担当区分：責任著者   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）

Since seawater has high attenuation of electromagnetic waves, the transmitting and receiving antennas are magnetically coupled using a coil with a diameter of 80 cm. The antenna is submerged in saltwater, and insertion loss is measured using a VNA. The communication speeds experiment of the UDP and TCP protocols is conducted when the distance between the transmitter and receiver antenna is changed.

Scopus

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担当区分：責任著者   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）

Common-mode choke coil (CMC) is used in vehicles and electronic devices to improve electromagnetic compatibility (EMC), and the analysis of the CMC effect is essential to improve the design quality of EMC. In this paper, the suppression effect of CMC for the common-mode (CM) signal converted from the differential-mode (DM) signal is analyzed using a chain-parameter matrix. The chain-parameter matrix of the CMC was obtained from the SPICE model and the measured data. And then, the amount of conversion level from DM signal to CM signal was calculated using the chain-parameter matrix of the signal source, the termination, the cable, and the CMC. The CM signal level was calculated for the shielded twisted pair cable with one pair considering imbalances of the signal source, the termination, the cable, and the CMC. The calculation value was compared to the measurement value due to confirm the validity of the method, and the calculated results were in close agreement with the measurement value. The investigation results showed that we should pay attention to the CMC imbalance when the cable is well balanced. In addition, the results suggested that the CMC should be prepared at both ends of the cable to reduce the current outside the shield.

DOI： 10.1109/EMCSI39492.2022.9889495

Scopus

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担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

DOI： 10.11486/ejisso.36.0_24b5-1

CiNii Research

担当区分：最終著者   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）

Radiated emission from shielded twisted pair (STP) cable was calculated using a chain-parameter-matrix. The series connection of the matrix represented the transmission line inside the shield, and the common-mode (CM) current was obtained by solving the matrix equation. The induction voltage on the outside of the shield was determined from the CM current using the shield's transfer impedance. The current on the outside of the shield was calculated from this induction voltage. And then, the radiated electric field was calculated from this current. The matrix elements representing the transmission line between conductors and shield were determined from the measurement, and the transfer impedance was also determined from the measurement. The line constants between shield and ground were determined from the theory by assuming the shield as a copper rod. The maximum current on the outside of the shield and the maximum radiated electric field were measured in the frequency range from 30 MHz to 300 MHz, and these were compared to the calculated value. The calculation results of the maximum current intensity were well agreed with the measured value, and the calculation results of the maximum radiated electric-field strength were almost agreed with the measured value.

DOI： 10.1109/EMC/SI/PI/EMCEurope52599.2021.9559295

Scopus

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担当区分：責任著者   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）

A mode division multiplex transmission system that assigns signals to the eigenmodes of a transmission line was proposed for a cable that is uniform in the longitudinal direction. The transmission characteristics when the proposed method is used in a 1m long shielded untwisted 4-wire cable were verified by circuit simulation. It is shown that the proposed method enables four-channel simultaneous transmission. In addition, the proposed method significantly improves the crosstalk compared to the differential and single-ended transmission methods.

DOI： 10.1109/EMC/SI/PI/EMCEurope52599.2021.9559178

Scopus

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.

DOI： 10.1002/eej.23324

Scopus

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担当区分：最終著者   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）

In a conventional TLP system, the pulse disturbance is applied to the DUT via the transmission line, whose characteristic impedance is 50 Ω. However, the DUT for the evaluation, such as an ESD protection device, may be affected by the transmission line’s characteristic impedance. This paper adds an impedance matching circuit to the conventional 50 Ω TLP system, making it possible to adjust the circuit to an arbitrary value of the transmission line’s characteristic impedance. By using the developed system, the IV characteristics of an ESD protection device are evaluated when the characteristic impedance is 20 Ω, 50 Ω, and 150 Ω. As a result, it was found that the negative resistance characteristics after the breakdown voltage change depending on the transmission line’s characteristic impedance.

DOI： 10.1109/ICSJ52620.2021.9648864

Scopus

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担当区分：最終著者   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）

A common-mode choke coil (CMC) is an essential device for achieving electromagnetic compatibility (EMC). An equivalent circuit considering the common-mode (CM) disturbance converted from differential-mode (DM) signal is needed because the spectrum of telecommunication signals overlaps with the regulated frequency band of the radiated disturbance due to the increase of telecommunication speed in recent years. In this paper, an equivalent circuit of CMC considering the conversion phenomenon is proposed. The admittances were inserted between each terminal of the CMC and the ground for demonstrating the phenomenon. The SPICE model of CMC was represented by the combination of the ABCD chain-parameter-matrices, and the elements of the overall matrix were calculated. The mixed-mode S-parameters were calculated using these elements. The elements of the ABCD matrix and the mixed-mode S-parameters were measured and the admittance values were determined by comparing the calculated data with the measured data. The pulse response calculated by the proposed equivalent circuit was well agreed with the measurement value.

DOI： 10.1109/EMCCompo52133.2022.9758620

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   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）

Italy  

The radiated emission of the power line communication (PLC) system should be investigated to maintain electromagnetic compatibility. Recently, the development of applying the PLC system to factories and offices was started. In these environments, many cables are arranged in the cable tray. Therefore, the multi-cable effect should be investigated. In this paper, the multi-cable effect was examined by using the scale model. The 0.5 times scale model was constructed in the semi-anechoic chamber, and the maximum common-mode (CM) current was measured by changing position along with the cable. The measured result was agreed with the result using the full-size original model. The experiment by using five cables suggested that the influence by the conductive loss and the dielectric loss of cable was not large for the maximum CM current, and the CM current was dominated by the cancellation effect of the in-phase currents flowing on the cables. The investigation for dependency of the position of the signal apply was indicated that the effect can be roughly estimated from the current division factor.

DOI： 10.1109/EMCEUROPE48519.2020.9245704

Scopus

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担当区分：責任著者   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）

Italy  

In this paper, reduction effect of a common-mode filter is discussed. When the performance of a common-mode filter is evaluated, it is necessary to consider not only SCC21 but also SCD21. Using these two parameters, the common-mode current flowing on the secondary side of the common-mode filter was formulated. Common-mode current is a summation of two causes: common-mode transmission and differential mode conversion from a signal source. The common-mode current depends on not only the phase relationship between SCC21 and SCD21 of the common-mode filter but also the phase relationship between the differential mode and the common mode of the signal source. Even if the same common-mode filter is used on a differential signaling system, the common-mode current increases or decreases depending on the phase of the differential mode voltage and the common-mode voltage at the signal source.

DOI： 10.1109/EMCEUROPE48519.2020.9245809

Scopus

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担当区分：責任著者   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）

Italy  

Power line communication (PLC) is the technology that uses a power line as a signal line. Because an imbalance of the power line is generally larger than that of the communication line, we should take care of radiated emission from the PLC cable. A small-scale model can be applied to evaluate easily the radiated emission from PLC cables for large structures. In a scale model, all structures in the PLC system need to be manufactured as 1/n size to satisfy complete equivalence between the reference model and its scale model, though it is difficult to fabricate the fine structure such as conductors in a cable smaller. Therefore we investigated the effect on common-mode current when some parameters of the scale model were not scaled down perfectly. As a result, a reliable scale model was obtained to evaluate peak common-mode currents in resonant frequency even if some parameters of the structure were incompletely scaled. Furthermore, the cable length dependency of common-mode current was evaluated experimentally by using the scale model.

DOI： 10.1109/EMCEUROPE48519.2020.9245868

Scopus

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担当区分：責任著者   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）

USA  

The common-mode filter (CMF) is a key device for suppressing emissions radiated from telecommunication cables. Recent serial interfaces deliver the necessity of considering that common-mode (CM) disturbances are converted from the differential mode (DM) telecommunication signals by a CMF. To examine this phenomenon, this study investigated the S_{\text{cd}21} characteristic, which is one of the mixed-mode S-parameters. Two types of CMFs whose S_{\text{cd}21} were different were examined. A signal was supplied to an unshielded twisted pair (UTP) cable through the CMF. The emission from the cable was measured using a setup complying with CISPR 25. Then, the relationship between the ratio of CM to DM signals and the emission level was investigated. The results showed that the emission level decreased as a result of employing the lower S_{\text{cd}21} CMF and that the emission level was linearly proportional to the ratio of the CM to DM signals. The results indicate that {S}_{\text{cd}21} is an essential parameter with which to evaluate CMFs used in telecommunication ports of serial interfaces.

DOI： 10.1109/EMCSI38923.2020.9191645

Scopus

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担当区分：責任著者   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）

The differential mode impedance (DMZ) and the longitudinal conversion loss (LCL) are important parameters to introduce high-speed power line communication (PLC) systems. Therefore, we should evaluate the DMZ and LCL in a factory environment because the three-phase power distribution system has been employed in factories. The admittance matrix elements at the power distribution board were determined from S-parameter measured with a vector network analyzer. An isolation probe was developed to measure S-parameters under high voltage applying conditions. Measurements were carried out at 60 points in 4 factories. The admittance matrix was represented by the equivalent circuit composed by six impedances, then the DMZ and the LCL were calculated from the mean value of the impedances. The results showed that the absolute value of DMZ was lower than the characteristic impedance of the PLC transmission line, and the LCL value was similar to the LCL in house environment where a two-phase power distribution system was employed.

DOI： 10.1109/ISPLC48789.2020.9115393

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>The analysis method using the chain parameter matrix (F-matrix) has been proposed for calculating radiated emission from the cable used by power line communication (PLC). In this paper, the radiation resistance was implemented to the F-matrix as the load of the common mode current which was converted from the differential mode PLC signal by the unbalance of the transmission system and was considered as the emission source. The calculated result for the simple cable model was compared to the measurement value and to the calculation value of which the radiation resistance was not considered. The investigation result indicated that the influence of radiation resistance appeared at the frequency where the high radiated emission was observed.</p>

DOI： 10.1587/comex.2020XBL0070

CiNii Article

CiNii Research

その他リンク： https://ci.nii.ac.jp/naid/130007895332

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

<p>In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.</p>

DOI： 10.1541/ieejfms.140.557

Scopus

CiNii Article

CiNii Research

その他リンク： https://ci.nii.ac.jp/naid/130007948596

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

DOI： 10.5104/jiep.22.622

Scopus

CiNii Article

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jiep/22/7/22_622/_pdf

担当区分：責任著者   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）

Spain   Barcelona   2019年09月

担当区分：責任著者   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）

Characteristics of radiated emission from the three-wire power cable where the power line communication signal was transmitting was studied by using circuit theory. The simple model whose length was 14.4m was used for the investigation, and the radiated emission was calculated and measured. The average deviation between the calculated data and the measured data was -3.6dB and the standard deviation was 3.3dB. The calculation results indicated that the maximum magnetic field strength could be estimated from the maximum common-mode current. The analysis also suggested that the maximum common-mode current of a three-wire cable was less than that of a two-wire cable in many cases.

DOI： 10.1109/EMCEurope.2019.8872015

Scopus

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担当区分：責任著者   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）

USA   New Orleans   2019年07月

担当区分：責任著者   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）

Japan   Sapporo   2019年06月

担当区分：責任著者   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）

Japan   Sapporo   2019年06月

担当区分：最終著者   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）

Electromagnetic field radiated from Power Line Communication (PLC) which was applied to three wires system was examined with Method of Moments (MoM). The influence of the wire configuration and the terminating condition of the third wire was also evaluated. Calculated common mode current and electromagnetic field intensity agreed well with measured results. The calculation results showed that electromagnetic field intensity decreased or didn't change from two wires system when the third wire was connected to the ground.

DOI： 10.23919/EMCTokyo.2019.8893771

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>The relation between maximum common mode current and maximum radiated magnetic field strength was experimentally studied using a simple power distribution line model. The common mode current was measured along the cable and the radiated magnetic field strength was measured around the model. They were evaluated using the <i>S</i>₂₁ parameter. The frequency characteristic of both the maximum current and the maximum strength showed a closely similar pattern. Our evaluation of their correlation indicated that the relation between the maximum common mode current and the maximum radiated magnetic field strength could be represented by a straight line, and that 80% of the measured data was contained within 2 dB of the regression line.</p>

DOI： 10.1587/comex.2019XBL0004

CiNii Article

CiNii Research

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

現在，500mを超える長距離区間で電力線通信(PLC)を使うケースが増えている。そのため電力線ケーブルの高周波透過特性を調べることが必要である。本報告ではVVFケーブルとEEFケーブルの透過特性を測定した。全帯域を使える長さはVVFケーブルでは0.3 kmであるが，EEFケーブルでは1.5k mである。よって長距離通信ではEEFケーブルを用いることが望ましい。今後は他のケーブルも測定することでより良い透過特性を持つケーブルの検証を実施する。

DOI： 10.12792/iiae2019.022

CiNii Article

CiNii Research

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>近年,自動運転技術などの発達により,車載通信の大容量化が求められている.この要求に対して,通信容量が比較的大きいEthernetを車載用途に転用する動きがある. Ethernetはオフィスや家庭で使用されてきたため,車載用途と比較して信頼性要求は高くない.</p><p></p><p>そこで本研究では,信頼性の評価方法を定めるため,Ethernetが弱点とする妨害波のパラメータを探ることを目的とした.そのために,妨害波として差動のパルス電圧を通信中のEthernetケーブルに対して印加し,その妨害波のパラメータとパケットエラーレートの相関を調査した.この論文ではその結果を報告する.</p>

DOI： 10.11486/ejisso.33.0_12c2-04

CiNii Article

CiNii Research

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>PLCなど電力線上の高周波電流を測定する際、低周波電流による磁気飽和をしないロゴスキーコイルを用いる必要がある。</p><p></p><p>本論文では、モーメント法を用いた電磁界解析プログラムであるNEC2によるシミュレーションにより伝達インピーダンスを求め、所望の高周波電流を測定できるロゴスキーコイルを設計した。</p><p></p><p>設計したロゴスキーコイルを作製・評価し、電力線上のPLC信号の電流測定を行った。</p>

DOI： 10.11486/ejisso.33.0_11d3-02

CiNii Article

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：筆頭著者   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）

Japan   Kitakyushu  

担当区分：責任著者   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）

USA   Boston  

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   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）

Italy   Sorrento  

担当区分：責任著者   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）

Netherlands   Maastricht  

担当区分：筆頭著者   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）

USA   Minnesota  

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   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）

Japan   Tokyo  

担当区分：筆頭著者   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）

Canada   Montreal  

記述言語：日本語

記述言語：日本語

開催期間： 2020年01月   記述言語：日本語  

開催期間： 2020年01月   記述言語：日本語  

開催期間： 2020年01月   記述言語：日本語  

開催期間： 2019年10月17日   記述言語：日本語  

開催期間： 2019年10月17日   記述言語：日本語  

開催期間： 2019年09月   記述言語：日本語  

開催期間： 2019年08月27日   記述言語：日本語  

開催期間： 2019年07月11日   記述言語：日本語  

開催期間： 2019年03月11日   記述言語：日本語  

開催期間： 2019年03月11日   記述言語：日本語  

開催期間： 2019年03月05日   記述言語：日本語  

開催期間： 2019年03月05日   記述言語：日本語  

開催期間： 2019年03月05日   記述言語：日本語  

開催期間： 2019年03月05日   記述言語：日本語  

開催期間： 2019年03月05日   記述言語：日本語  

開催期間： 2019年01月   記述言語：日本語  

開催期間： 2019年01月   記述言語：日本語  

開催期間： 2019年01月   記述言語：日本語  

開催期間： 2019年01月   記述言語：日本語  

開催期間： 2019年01月   記述言語：日本語  

開催期間： 2019年01月   記述言語：日本語  

開催期間： 2018年11月22日 - 2018年11月23日   記述言語：英語   開催地：KAIST, Daejeon< Korea  

開催期間： 2018年09月   記述言語：日本語  

開催期間： 2018年09月   記述言語：日本語  

開催期間： 2018年09月   記述言語：日本語  

開催期間： 2017年10月   記述言語：英語  

開催期間： 2016年12月07日   記述言語：日本語  

開催期間： 2013年04月05日   記述言語：日本語  

開催期間： 2013年04月   記述言語：日本語  

開催期間： 2010年06月05日   記述言語：日本語  

開催期間： 2008年04月11日   記述言語：日本語  

開催期間： 2007年01月   記述言語：日本語  

開催期間： 2005年08月   記述言語：日本語  

開催期間： 2001年11月15日   記述言語：日本語  

開催期間： 2001年07月06日   記述言語：日本語  

開催期間： 2001年05月18日   記述言語：日本語  

開催期間： 2000年12月08日   記述言語：日本語  

開催期間： 2000年11月14日   記述言語：日本語  

開催期間： 2000年06月   記述言語：日本語  

開催期間： 2000年04月19日   記述言語：日本語  

開催期間： 2000年03月01日   記述言語：日本語  

開催期間： 1999年12月22日   記述言語：日本語  

開催期間： 1999年12月22日   記述言語：日本語  

開催期間： 1999年12月03日   記述言語：日本語  

開催期間： 1999年11月26日   記述言語：日本語  

開催期間： 1999年11月   記述言語：日本語  

開催期間： 1999年09月17日   記述言語：日本語  

開催期間： 1999年03月08日   記述言語：日本語  

開催期間： 1999年03月08日   記述言語：日本語  

開催期間： 1999年03月03日   記述言語：日本語  

開催期間： 1998年10月15日   記述言語：日本語  

開催期間： 1998年07月10日   記述言語：日本語  

開催期間： 1990年10月08日   記述言語：日本語  

開催期間： 2016年01月   発表言語：日本語   講演種別：基調講演  

開催期間： 2012年06月   発表言語：日本語   講演種別：招待講演  

開催期間： 2010年11月   発表言語：日本語   講演種別：招待講演  

開催期間： 2007年09月   発表言語：英語   講演種別：招待講演  

開催期間： 2006年08月   発表言語：日本語   講演種別：特別講演