著者

土井 猛 辻 裕之 木村 誠聡

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.7, pp.480-484, 2022-07-01

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書籍をデータ化する際に様々なスキャナやスマートフォンのカメラを用いて撮影した画像には湾曲するひずみが確認されている.これは綴じている文書に対し上部から撮影を行った場合に確認される現象で,綴じた辺に向け湾曲したひずみが生じる.このひずみを補正する方法は種々存在するが,一つのアルゴリズムでさまざまなひずみを補正する方法は存在しない.本論文では最小2乗法とAICによる次数選択を行い,文書画像のひずみ形状を限定しない補正手法を提案する.結果としてOCR機能による認識実験において,提案手法は93%の認識成功率を示すことを確認した.

著者

Eiji YOSHIYA Tomoya NAKANISHI Tsuyoshi ISSHIKI

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.7, pp.1061-1069, 2022-07-01

被引用文献数

2

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In Internet of Things (IoT) applications, system-on-chip (SoCs) with embedded processors are widely used. As an embedded processor, RISC-V, which is license-free and has an extensible instruction set, is receiving attention. However, designing such embedded processors requires an enormous effort to achieve a highly efficient microarchitecture in terms of performance, power consumption, and circuit area, as well as the design verification of running complex software, including modern operating systems such as Linux. In this paper, we propose a method for directly describing the RTL structure of a pipelined RISC-V processor with cache memories, a memory management unit (MMU), and an AXI bus interface using the C++ language. This pipelined processor C++ model serves as a functional simulator of the complete RISC-V core, whereas our C2RTL framework translates the processor C++ model into a cycle-accurate RTL description in the Verilog-HDL and RTL-equivalent C model. Our processor design methodology using the C2RTL framework is unique compared to other existing methodologies because both the simulation and RTL models are derived from the same C++ source, which greatly simplifies the design verification and optimization processes. The effectiveness of our design methodology is demonstrated on a RISC-V processor that runs Linux OS on an FPGA board, achieving a significantly short simulation time of the original C++ processor model and RTL-equivalent C model in comparison to a commercial RTL simulator.

著者

Fumihiro CHINA Naoki TAKEUCHI Hideo SUZUKI Yuki YAMANASHI Hirotaka TERAI Nobuyuki YOSHIKAWA

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.6, pp.264-269, 2022-06-01

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The adiabatic quantum flux parametron (AQFP) is an energy-efficient, high-speed superconducting logic device. To observe the tiny output currents from the AQFP in experiments, high-speed voltage drivers are indispensable. In the present study, we develop a compact voltage driver for AQFP logic based on a Josephson latching driver (JLD), which has been used as a high-speed driver for rapid single-flux-quantum (RSFQ) logic. In the JLD-based voltage driver, the signal currents of AQFP gates are converted into gap-voltage-level signals via an AQFP/RSFQ interface and a four-junction logic gate. Furthermore, this voltage driver includes only 15 Josephson junctions, which is much fewer than in the case for the previously designed driver based on dc superconducting quantum interference devices (60 junctions). In measurement, we successfully operate the JLD-based voltage driver up to 4 GHz. We also evaluate the bit error rate (BER) of the driver and find that the BER is 7.92×10-10 and 2.67×10-3 at 1GHz and 4GHz, respectively.

著者

清水 大地 児玉 謙太郎 関根 和生

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.J104-A, no.2, pp.75-83, 2021-02-01

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上演芸術の一つの魅力として,複数名の演者間に生じる複雑な関わり合いが挙げられる.近年では,この関わり合いの特徴を同期・協調の理論を適用し,定量的に検討する試みが営まれつつある.以上の研究は,主に単独の表現チャンネル(頭のリズム運動,歌声,腕の運動等)を対象とし検討を行ってきた.一方で上演芸術では,表情,ジェスチャー,リズム運動等のように複数の表現チャンネルを通して演者達が関わり合う様子が観察されており,その過程に魅力が含まれるとする理論的提案もなされつつある.本研究では,以上の複数の表現チャンネルを通した関わり合いの探索的・定量的検討を試みた.具体的には,近年演者間の同期・協調の検証対象として着目されている競争的場面としてフリースタイルラップバトルを対象とし,熟達したラッパー2名の関わり合いを手,頭,腰の同期・協調の様相に着目して測定・解析した.結果,複数の表現チャンネルにおいて演者間の同期が生起する様子,手では同位相同期,頭・腰では逆位相同期と演者間の同期の様相がチャンネルにより異なる様子,手と頭・腰を異なる役割を担うチャンネルとして利用していた様子,が観察された.

著者

Shahrzad Mahboubi Indrapriyadarsini S Hiroshi Ninomiya Hideki Asai

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.12, no.3, pp.554-574, 2021 (Released:2021-07-01)

参考文献数

33

被引用文献数

1 4

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This paper describes a momentum acceleration technique for quasi-Newton (QN) based neural network training and verifies its performance and computational complexity. Recently, Nesterov's accelerated quasi-Newton method (NAQ) has been introduced and shown that the momentum term is effective in reducing the number of iterations and the total training time by incorporating Nesterov's accelerated gradient into QN. However, the gradients had to be calculated two times in one iteration in the NAQ training. This increased the computation time of a training loop compared with the conventional QN. The proposed technique is an improvement to NAQ done by approximating the Nesterov's accelerated gradient as a linear combination of the current and previous gradients. As a result, the gradient is calculated only once per iteration similar to that of QN. The performance of the proposed algorithm is evaluated in comparison to conventional algorithms in neural networks training on two types of problems - function approximation problems with high nonlinearity and classification problems. The results show a significant acceleration in the computation time without losing the quality of the solution compared with conventional training algorithms.

著者

Eiji Okamoto

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.12, no.3, pp.257-274, 2021 (Released:2021-07-01)

参考文献数

35

被引用文献数

2

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In recent years, there have been several advances in wireless communication systems, including the increase in transmission rate, and as a result, they are playing an increasingly significant role in our lives. To meet the widespread application scope, the commercialization of the fifth-generation mobile communications system (5G) has been initialized. This paper gives an overview of the 5G system and discusses the nonlinear signal processing technologies that support its performance improvement. Here, the term “nonlinear signal processing” is defined as an algorithm for transmitting and receiving data in communications that uses a nonlinear mechanism. Because there is a significant shortage of frequency bands in wireless communications, advanced technologies are being integrated to maximize frequency utilization. In addition, unlike in the 4G era, there are additional use cases that require performance guarantees for quality, delay, and the number of multiple connections in the 5G system, and the performance requirements for wireless systems are becoming more stringent. Nonlinear signal processing is key to improving the performance of these systems, and this paper outlines the nonlinear technology used in 5G wireless access. We will introduce multiple-input multiple-output transmission and non-orthogonal multiple access (NOMA), which will help improve the performance of wireless systems. In addition, we introduce a radio wave-encrypted NOMA with a physical layer security that is proposed by the authors. Furthermore, the technical trend of 6G is briefly introduced.

著者

Dashan Shi Jia Yuan Jialu Yin Yulian Wang Shushan Qiao

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.10, pp.20220089, 2022-05-25 (Released:2022-05-25)

参考文献数

37

被引用文献数

2

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This paper presents a half-selected robust 12T bitcell with built-in write-assist for sub-threshold SRAM. The proposed 12T bitcell is robust enough in bit-interleaving architecture to enhance soft-error immunity combined with error correction code. The read stability of the proposed bitcell is improved by read decoupled. The writability is improved by data-dependent supply-cutoff write-assist. Both row and column f-selected bitcells can hold data stably during write operations. Simulation results based on a standard 55nm CMOS technology show that the read static noise margin of the proposed bitcell is 16.13x as that of the conventional 6T bitcell. Moreover, the write failure in the sub-threshold region is eliminated. In addition, the leakage consumption is improved by 15.7% compared with 6T bitcell.

著者

Ryo Kato Mamoru Okumura Eiji Okamoto

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Communications Express (ISSN:21870136)

巻号頁・発行日

vol.11, no.5, pp.189-194, 2022-05-01 (Released:2022-05-01)

参考文献数

6

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In 5G vehicular communications, beamforming technologies for vehicles, which compensate for large propagation losses at high carrier frequencies, are being considered. However, because the deflected beamforming loss degrades the communication quality, an accurate beam tracking system that follows the movement of the vehicle is required. In conventional schemes using a periodic codebook, the main lobe often deviates from the direction of the base station owing to fast movement. Therefore, in this study, a scheme for adaptively generating beam candidates using beam selection logs and the steering angle of the vehicle is proposed. Numerical results show that the scheme has high accuracy.

著者

Chongyu YU Jun FENG

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.5, pp.184-193, 2022-05-01

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A linear and broadband power amplifier (PA) for 5G phased-array is presented. The design improves the linearity by operating the transistors in deep class AB region. The design broadens the bandwidth by applying the inter-stage weakly-coupled transformer. The theory of transformers is illustrated by analyzing the odd- and even-mode model. Based on this, the odd-mode Q factor is used to evaluate the quality of impedance matching. Weakly- and strongly-coupled transformers are compared and analyzed in both the design process and applicable characteristics. Besides, a well-founded method to achieve the transformer-based balanced-unbalanced transformation is proposed. The fully integrated two-stage PA is designed and implemented in a 65-nm CMOS process with a 1-V power supply to provide a maximum small-signal gain of 19dB. The maximum output 1-dB compressed power (P1dB) of 17.4dBm and the saturated output power (PSAT) of 18dBm are measured at 28GHz. The power-added efficiency (PAE) of the P1dB is 26.5%. From 23 to 32GHz, the measured P1dB is above 16dBm, covering the potential 5G bands worldwide around 28GHz.

著者

Katsuki TOKANO Wenqi ZHU Tatsuki OSATO Kien NGUYEN Hiroo SEKIYA

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.494-503, 2022-05-01

被引用文献数

4

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This paper presents a design method of a two-hop wireless power transfer (WPT) system for installing on a robot arm. The class-E inverter and the class-D rectifier are used on the transmission and receiving sides, respectively, in the proposed WPT system. Analytical equations for the proposed WPT system are derived as functions of the geometrical and physical parameters of the coils, such as the outer diameter and height of the coils, winding-wire diameter, and number of turns. Using the analytical equations, we can optimize the WPT system to obtain the design values with the theoretically highest power-delivery efficiency under the size limitation of the robot arm. The circuit experiments are in quantitative agreement with the theoretical predictions obtained from the analysis, indicating the validity of the analysis and design method. The experimental prototype achieved 83.6% power-delivery efficiency at 6.78MHz operating frequency and 39.3W output power.

著者

Tetsuya MANABE Kosuke OMURA

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.5, pp.778-786, 2022-05-01

被引用文献数

1

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This paper evaluates the bluetooth low energy (BLE) positioning systems using the sparse-training data through the comparison experiments. The sparse-training data is extracted from the database including enough data for realizing the highly accurate and precise positioning. First, we define the sparse-training data, i.e., the data collection time and the number of smartphones, directions, beacons, and reference points, on BLE positioning systems. Next, the positioning performance evaluation experiments are conducted in two indoor environments, that is, an indoor corridor as a one-dimensionally spread environment and a hall as a twodimensionally spread environment. The algorithms for comparison are the conventional fingerprint algorithm and the hybrid algorithm (the authors already proposed, and combined the proximity algorithm and the fingerprint algorithm). Based on the results, we confirm that the hybrid algorithm performs well in many cases even when using sparse-training data. Consequently, the robustness of the hybrid algorithm, that the authors already proposed for the sparse-training data, is shown.

著者

Kunye Feng Zile Fan

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.9, pp.20220094, 2022-05-10 (Released:2022-05-10)

参考文献数

38

被引用文献数

2

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Breathing monitoring is important in the health and sports area. In this paper, a wireless self-powered health system for breathing monitoring is designed using the piezoelectric devices and buckled n-shape and L-shape structure. A cotton belt is used to tie the system to the chest and deliver the force stimulated by the chest cavity enlargement caused by the breathing, which can be collected and measured based on the three-dimension n-shape and L-shape structure. Three hard lead zirconate titanate (PZT) patches are used as the energy source to support the sensing circuit and soft piezoelectric polyvinylidene fluoride (PVDF) works as the sensor to measure the stretching force, which are placed at the gap between the 3D-printed n-shape and L-shape structure, making the measurement more precise. Breathing signal comparison between commercially used battery-powered respiration belts shows the efficiency of the piezoelectric devices on the accuracy, precision, and recall factors. The system is also used in practical experiments and it is found that the intense actions have a similar peak-peak value of breathing wavefront but a much higher frequency of respiration. This design can be used in health monitoring and sports training, which also shows the potential of data acquisition for disease diagnosis applications.

著者

Shiyao DING Donghui LIN

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.5, pp.864-872, 2022-05-01

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With the high development of computation requirements in Internet of Things, resource-limited edge servers usually require to cooperate to perform the tasks. Most related studies usually assume a static cooperation approach which might not suit the dynamic environment of edge computing. In this paper, we consider a dynamic cooperation approach by guiding edge servers to form coalitions dynamically. It raises two issues: 1) how to guide them to optimally form coalitions and 2) how to cope with the dynamic feature where server statuses dynamically change as the tasks are performed. The coalitional Markov decision process (CMDP) model proposed in our previous work can handle these issues well. However, its basic solution, coalitional Q-learning, cannot handle the large scale problem when the task number is large in edge computing. Our response is to propose a novel algorithm called deep coalitional Q-learning (DCQL) to solve it. To sum up, we first formulate the dynamic cooperation problem of edge servers as a CMDP: each edge server is regarded as an agent and the dynamic process is modeled as a MDP where the agents observe the current state to formulate several coalitions. Each coalition takes an action to impact the environment which correspondingly transfers to the next state to repeat the above process. Then, we propose DCQL which includes a deep neural network and so can well cope with large scale problem. DCQL can guide the edge servers to form coalitions dynamically with the target of optimizing some goal. Furthermore, we run experiments to verify our proposed algorithm's effectiveness in different settings.

著者

Jinho CHOI Taehwa LEE Kwanwoo KIM Minjae SEO Jian CUI Seungwon SHIN

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.4, pp.824-827, 2022-04-01 (Released:2022-04-01)

参考文献数

8

被引用文献数

3

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Bitcoin is currently a hot issue worldwide, and it is expected to become a new legal tender that replaces the current currency started with El Salvador. Due to the nature of cryptocurrency, however, difficulties in tracking led to the arising of misuses and abuses. Consequently, the pain of innocent victims by exploiting these bitcoins abuse is also increasing. We propose a way to detect new signatures by applying two-fold NLP-based clustering techniques to text data of Bitcoin abuse reports received from actual victims. By clustering the reports of text data, we were able to cluster the message templates as the same campaigns. The new approach using the abuse massage template representing clustering as a signature for identifying abusers is much efficacious.

著者

Junjie Lu Xiaogang Chen Shunfen Li Xinyu Qian Aximu Yuemaier Zhitang Song

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.8, pp.20220079, 2022-04-25 (Released:2022-04-25)

参考文献数

34

被引用文献数

3

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Edge intelligence (EI), as a combination of artificial intelligence (AI) and internet of things (IoT), is the key to realize an interconnected world of everything. EI needs to process the data collected by edge devices locally. For edge devices with insufficient computing power, a near data computing (NDC) system can provide local computing capability by adding a co-processing unit near the memory. NDC systems are extensively studied focused on the optimization of the hardware architecture but lack of universal and transparent system support. Meanwhile, we notice that non-volatile memory (NVM) plays an important role in edge intermittent computing. In this article, we propose a novel in-memory processing file system (IMPFS) based on NVM to provide general support for NDC system running on edge devices. IMPFS uses standard file system interfaces and is optimized for NVM and AI application management. To verify the IMPFS, a prototype system is designed. The results showed that the IMPFS can not only provide universal support for EI but also further improve the processing speed by reducing the redundant software overhead.

著者

Kazuya Sawada Yutaka Shimada Tohru Ikeguchi

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.13, no.2, pp.385-390, 2022 (Released:2022-04-01)

参考文献数

22

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State space reconstruction using time-delay coordinate systems is the most effective and significant technique for analyzing complex time series generated by nonlinear dynamical systems. In this study, we investigated the relationships between reconstruction parameters and the similarity of the structural properties of original and reconstructed attractors. In particular, we investigated the similarities between inter-point distance distributions on original and reconstructed attractors, while varying the reconstruction parameters for reconstructing a dynamical system using a time-delay coordinate system. The results show that the product of the reconstruction dimension and the time-delay should be constant to obtain high similarity.

著者

Osamu Kagaya Takafumi Kikuchi Keisuke Arai Takuji Arima Toru Uno

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Communications Express (ISSN:21870136)

巻号頁・発行日

vol.11, no.2, pp.93-97, 2022-02-01 (Released:2022-02-01)

参考文献数

4

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In this paper, the effect of raindrops on an on-glass antenna is evaluated to appropriately design a C-band automotive antenna. A three-layer composite glass is used for the automotive window glass panel. The electromagnetic field analysis of a dipole on-glass antenna placed in the center of a 300 mm × 300 mm flat composite glass was performed. As a result, it was found that raindrop situation had no significant effect on the reflection characteristics of the antenna. However, the reflection coefficient of the antenna worsens when the raindrops were connected to each other and streaked in a direction parallel to the antenna.

著者

Shiwen LIN Yawen ZHOU Weiqin ZOU Huaguo ZHANG Lin GAO Hongshu LIAO Wanchun LI

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.4, pp.673-681, 2022-04-01

被引用文献数

1

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Estimating the spatial parameters of the signals by using the effective data of a single snapshot is essential in the field of reconnaissance and confrontation. Major drawback of existing algorithms is that its constructed covariance matrix has a great degree of rank loss. The performance of existing algorithms gets degraded with low signal-to-noise ratio. In this paper, a three-parallel linear array based algorithm is proposed to achieve two-dimensional direction of arrival estimates in a single snapshot scenario. The key points of the proposed algorithm are: 1) construct three pseudo matrices with full rank and no rank loss by using the single snapshot data from the received signal model; 2) by using the rotation relation between pseudo matrices, the matched 2D-DOA is obtained with an efficient parameter matching method. Main objective of this work is on improving the angle estimation accuracy and reducing the loss of degree of freedom in single snapshot 2D-DOA estimation.

著者

Ryota ISHIBASHI Takuma TSUBAKI Shingo OKADA Hiroshi YAMAMOTO Takeshi KUWAHARA Kenichi KAWAMURA Keisuke WAKAO Takatsune MORIYAMA Ricardo OSPINA Hiroshi OKAMOTO Noboru NOGUCHI

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.4, pp.364-378, 2022-04-01

被引用文献数

2

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To sustain and expand the agricultural economy even as its workforce shrinks, the efficiency of farm operations must be improved. One key to efficiency improvement is completely unmanned driving of farm machines, which requires stable monitoring and control of machines from remote sites, a safety system to ensure safe autonomous driving even without manual operations, and precise positioning in not only small farm fields but also wider areas. As possible solutions for those issues, we have developed technologies of wireless network quality prediction, an end-to-end overlay network, machine vision for safety and positioning, network cooperated vehicle control and autonomous tractor control and conducted experiments in actual field environments. Experimental results show that: 1) remote monitoring and control can be seamlessly continued even when connection between the tractor and the remote site needs to be switched across different wireless networks during autonomous driving; 2) the safety of the autonomous driving can automatically be ensured by detecting both the existence of people in front of the unmanned tractor and disturbance of network quality affecting remote monitoring operation; and 3) the unmanned tractor can continue precise autonomous driving even when precise positioning by satellite systems cannot be performed.

著者

Jun SHIBAYAMA Takuma KURODA Junji YAMAUCHI Hisamatsu NAKANO

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.4, pp.159-162, 2022-04-01

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A periodic array of InSb spheres on a substrate is numerically analyzed at terahertz frequencies. The incident field is shown to be coupled to the substrate due to the guided-mode resonance. The effect of the background refractive index on the transmission characteristics is investigated for sensor applications.