電気学会論文誌C(電子・情報・システム部門誌)
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
145 巻, 1 号
選択された号の論文の17件中1~17を表示しています
特集:電子回路関連技術
特集論文
<電気回路・電子回路>
  • 戸谷 準, 松谷 康之
    2025 年 145 巻 1 号 p. 1-7
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    Switched Mode Power Supply (SMPS) is widely used as highly efficient stabilized power supply circuit. Triangular wave comparison PWM (TWC-PWM) control is commonly used in the way to regulate voltage. However, TWC-PWM is composed of analog circuits, and it needs to be re-designed if the manufacturing processes of ICs are changed. Furthermore, the accuracy of output voltage degrades because of the non-linearity of analog circuits. In this paper, we propose the SMPS using the Pulse Density Modulation (PDM) control with ΔΣ modulator. It is possible to be composed the ΔΣ modulator by only logic circuits, therefore re-design is not need. Limit cycle oscillation occurs when DC is input to ΔΣ modulator. But it can be suppressed adding AC dither. Dither decreases accuracy of output voltage. But it can be removed by interleaving and pseudo differentiating ΔΣ modulator. We propose improving process portability and accuracy of output voltage by applying digital control. Furthermore, we propose spreading focused spectrum using ΔΣ modulator.

  • 藤田 誉大, 和田 和千
    2025 年 145 巻 1 号 p. 8-15
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    This paper proposes a novel control strategy for wireless power transfer (WPT) circuits that achieves both load voltage regulation and maximum efficiency control for varied resistive loads. The proposed method is based on the characteristic that the input impedance of a switching voltage regulator depends on its input voltage. The switching regulator is utilized not only for load voltage regulation but also for impedance conversion to maximize the transfer efficiency. External communication circuits for feedback control from the secondary side to the primary side are unnecessary as the controllers on both sides operate independently. Experimental results approximately match the derived theoretical values and validate the proposed method.

  • 庄野 和宏, 佐藤 リナ, 深川 寛太, 谷本 洋, 武藤 浩二
    2025 年 145 巻 1 号 p. 16-24
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    This paper proposes a measurement technique for an integrated complex filter. The proposed method is based on two measurement methods with integrated circuitry for calibration. It is accomplished by applying square waves to an FUT (Filter Under Test) instead of sinusoidal waves or by superposing transfer characteristics obtained by applying a single sinusoidal wave to an FUT. In both of the above methods, the output signal connected to the external measurement equipment via a 50Ω coaxial cable and so on. In this case, the output signal of the FUT should be amplified by internal or external amplifiers, which degrades the response. However, it is cancelled out by the proposed calibration circuitry with some analog switches. In addition to the above, for the RC polyphase filter, the source resistance and the load capacitance degrade the measurement results and their effect is discussed. The validity of the proposal is confirmed through computer simulation for a third-order RCPF whose passband is 8-40MHz fabricated by Phenitec 0.6 μm CMOS process. It is shown that the measurement error is -1.10 dB for the square-wave method and -1.00 dB and -0.43 degrees for the superposition method at 40MHz.

  • 佐藤 リナ, 深川 寛太, 庄野 和宏, 谷本 洋, 武藤 浩二, 森山 誠二郎, 高橋 誓, 吉野 理貴
    2025 年 145 巻 1 号 p. 25-37
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    This paper describes the implementation and evaluation of an RC polyphase filter (RCPF) and circuitry for measuring its frequency characteristics. The integrated circuit is fabricated on a 0.6 μm CMOS process and its supply voltage is 5V. The integrated circuit includes a filter under test (FUT), a four-phase square wave generator, several analog switches and differential amplifiers to amplify the high-impedance signals of the RCPF. This FUT is a third-order complex RCPF whose passband is 8-40 MHz. This paper describes the design of these circuits in detail. This integrated circuit can select two measurement methods by means of external control signals. The first method uses a four-phase square wave. The frequency characteristics are measured by using an on-chip four-phase square wave generator driven by an external clock generator and by a spectrum analyzer tuned to the fundamental frequency. The second method uses an external network analyzer. Furthermore, this integrated circuit is equipped with a calibration circuit to measure the frequency characteristics of the circuitry except FUT by passing through the input / output signals of the FUT. As a result, the frequency characteristics of the FUT itself can be accurately measured. The effectiveness is confirmed through evaluation of the fabricated integrated circuit.

  • Yuanchi Chen, Hao San, Haijun Lin
    2025 年 145 巻 1 号 p. 38-44
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    This paper presents a floating sampling technique for CMOS SAR ADCs that tolerates large input amplitude exceeding the supply voltage. A novel switched-capacitor sample-and-hold (S/H) circuit incorporating the proposed floating sampling technique effectively attenuates large input amplitudes within the specified range of low supply voltage SAR ADCs, regardless of the common level of the analog input. A 0.7 V 12-bit SAR ADC with the proposed floating sampling circuit is designed in 65 nm SOTB CMOS technology. Simulated SNDR=63.74 dB, SFDR=79.84 dB and ENOB=10.30 bits are achieved while a sinusoid input Vin_ppd=2.8 V (peak-to-peak voltage of differential input voltage) biased at Vin,CM=1.4 V is sampled at 3 MS/s, including the thermal noise of MOSFETs and capacitors of the proposed SAR ADC. The SPICE simulation results also demonstrate that the dynamic performance of the proposed SAR ADC remains stable even when the input common-mode voltage Vin,CM is varied between 1.2 V and 1.6 V. These results indicate the feasibility and effectiveness of the proposed floating sampling technique in efficiently extending the dynamic range of the low supply voltage SAR ADC.

論文
<電気回路・電子回路>
<生体医工学・福祉工学>
  • ―学習データ拡張方法の考察―
    荒 翔太, 加藤 和夫, 門倉 博之, 石川 敦雄
    2025 年 145 巻 1 号 p. 52-58
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    In the development of brain-machine interfaces (BMIs), studies have been conducted to improve the accuracy of action using an electroencephalogram (EEG) to detect the neural activity of users when the BMI outputs an error against the intention of users and to provide feedback to the BMI. In this case, only a small number of EEG datasets can be prepared at the time of the error output. In addition, a large bias exists in the number of datasets between the error and no error outputs that affects the discrimination accuracy of machine learning. In this study, four methods for augmenting training data for one-dimensional convolutional neural networks were proposed, and their discrimination rates were compared. The method that eliminated the bias in the number of datasets between the labels of error and no error by data expansion by merging two datasets at the time of error output, obtained the highest discrimination rate of 0.728 compared with the other three methods.

<システム・計測・制御>
  • 畠山 隆
    2025 年 145 巻 1 号 p. 59-65
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    Volterra series was applied to river runoff phenomena to model the input-output nonlinear relation between rainfall and runoff of rivers. The application results were reported in “Electrical Engineering in Japan” (vol. 98, 101). In the report, good results from modeling and simulation were shown, meanwhile unfavorable results were also shown in some cases depending on modeling condition.

    The cause of unfavorable results was inferred as due to ill-conditioning of the coefficient matrix in the linear equation which was derived by expanding the Volterra kernels with the Laguerre function system. To solve this, advanced research was then conducted and reported in another publication where rank-reduced singular value decomposition was applied and adequate results were obtained.

    Thus, in this paper, the causes of ill-conditioning have been examined in the cases of impulse input and usual input to the 2nd order Volterra model. As a result, the fact that the coefficient matrix is of ill-conditioning has been verified mathematically.

<知能,ロボティクス>
  • 張 天翔, 道満 恵介, 目加田 慶人
    2025 年 145 巻 1 号 p. 66-73
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    This paper proposes an image inpainting method which can preserve the local appearance consistency of reconstructed images. The proposed method is based on PICNet, an existing image inpainting method. PICNet is composed of two paths based on a VAE-GAN architecture: reconstructive and generative pipelines, and can outputs multiple reconstruction results with various appearances from an input image. The discriminators in both the pipelines, however, have a problem that they evaluate not the local but the global appearances of input images. The proposed method replaces the discriminator in the generative pipeline with SN-PatchGAN, a discriminator evaluating on local image features. Also, the proposed method replaces the convolution layers in the SN-PatchGAN with partial convolution layers applied only to masked regions. We expect to achieve image inpainting with local appearance consistency by these two improvements, and actually confirmed the effectiveness of the proposed method against the existing method through quantitative and qualitative evaluations.

  • 芦川 凜空, 田中 雅博, 張 伯聞
    2025 年 145 巻 1 号 p. 74-82
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    In general, unsupervised learning is essential for the anomaly detection problem because it is difficult to collect anomaly data. As for anomaly detection algorithms using images, the SPADE algorithm, which has been tried on various industrial products, is used to detect anomalies using k-NN with only normal data as a prototype. The algorithm is applied to road surface images, where the concept of normality and abnormality is quite different from that of industrial products. The authors have been conducting research on image-based safety systems for mobility scooters, which are mainly used by elderly people and people with disabilities. In this paper, we experimentally confirm whether the system can detect objects with indefinite shapes such as garbage nets, plastic bottles, stands with signs or chains, and pole wires on the road, which cannot be learned by supervised learning due to the uncertainty of shapes.

<音声画像処理・認識>
  • Xuerong Cui, Min Li, Juan Li, Bin Jiang, Lei Li, Shibao Li
    2025 年 145 巻 1 号 p. 83-92
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    Side-scan sonar can effectively detect the burial state of submarine pipelines. However, when obtaining underwater images, the images generated by side-scan sonar have quality issues due to factors such as seabed interference, energy attenuation, and equipment limitations. For example, there is uneven grayscale. The quality of the image can be optimized by grayscale correction. But the current algorithms do not fully consider the texture details of the image and the scattering noise present in the marine environment. Therefore, this paper proposes a side-scan sonar enhancement method based on a guided filter hierarchical processing strategy. Firstly, the side-scan sonar image is decomposed into basic and detail layers using guided filter. The basic layer components of the image are fused using an adaptive gamma correction combining mean and variance and an improved fuzzy algorithm, aiming at gray scale correction, adjusting image brightness and improving contrast. The detail layer components are processed using a hybrid Butterworth filter combined with a Hamming window to enhance the texture information and remove the noise interference. Finally, the processed basic and detail layer components are reconstructed using weighted fusion to obtain the enhanced side-scan sonar image. Experiments show that the method can effectively achieve gray scale correction. And compared with the existing image enhancement methods, the method in this paper has significant improvement in Peak Signal-to-Noise Ratio (PSNR), Structural Similarity (SSIM), and Universal Quality Index (UQI). The values of the Natural Image Quality Evaluator (NIQE) and the Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE) are decreased.

<ソフトコンピューティング・学習>
  • 伊藤 陽, 奥津 大
    2025 年 145 巻 1 号 p. 93-100
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    When heavy rain hits, some utility poles for telecommunication were damaged because of landslides or road collapses. These damages may cause telecommunication disruptions, and this paper aims to build damage prediction to make countermeasures for mitigation and restore early. In this paper, we aim to construct a prediction technique that can estimate the damage to individual utility poles by using the damage results of southern Kumamoto during heavy rainfall in July 2020. In addition, the prediction model uses public data that are maintained nationwide to enable prediction at any location. As a result, we built a highly accurate prediction model with a PR-AUC of 0.71 in the test data and confirmed that the model can be interpretable.

  • 相吉 英太郎, 田村 健一, 安田 恵一郎
    2025 年 145 巻 1 号 p. 101-114
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    We attempt to combine optimization with modeling to construct approximate models of input-output relationships, which are called surrogate models. For modeling, we envision using machine-learning based on input-output data as inequality constraints for error tolerances to be embedded into optimization problems within the framework of the universal approximation theorem, and we refer these combining types of modeling and optimization problems as a modeling-driven optimization problem. Then, as a strategy for solving the modeling-driven optimization problem with a relatively large number of data, we propose the data restriction method, in which modeling-driven optimization problem is replaced with the data restriction problem with a reduced number of inequality constraints for error tolerances corresponding to the set of learning data restricted to a smaller number of elements, and the problems with restricted data are solved sequentially while new approximate models are iteratively constructed in order to improve accuracy of the obtained optimal solution.

  • Makoto Fukumoto, Yoshiko Hanada
    2025 年 145 巻 1 号 p. 115-121
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    Creating media content suited to each user's preferences and feelings is important. This study treats the search method for delicious blended juices using Interactive Evolutionary Computation (IEC) and especially aims to investigate the proposed IEC's behavior in search space. The investigations on the progress of the ratio contribute to establishing a more practical search method for blended juices. As the concrete algorithm, Genetic Algorithm (GA) was used. Moreover, six source juices composed of three fruit and three vegetable-like juices were employed in the experimental settings as a simpler setting compared with a previous study that could not show an increase in the fitness values in the evaluation process. As the experimental results, gradual increases in mean and maximum fitness values in the search experiment and a marginal increase in the re-evaluation experiment were confirmed. The progress of the convergence in the search area was also clarified in the search. Additionally, higher ratios in fruit source juices and lower ratios in vegetable source juices were observed as common trends in the composition of the best GA individuals. These results are dedicated to establishing a future IEC to find delicious and nutritious blended juices for each user.

研究開発レター
<情報処理・ソフトウェア>
  • Hirofumi Sanada, Megumi Takezawa, Hisaaki Ota, Hidekazu Saito
    2025 年 145 巻 1 号 p. 122-123
    発行日: 2025/01/01
    公開日: 2025/01/01
    ジャーナル 認証あり

    This study presents the development of a tablet PC-based Line Bisection Task (LBT) software. The software was created through an iterative process involving collaboration between software developers and occupational therapy researchers, incorporating user feedback to refine the prototype. The resulting software addresses the limitations of traditional paper-and-pencil LBT methods, underscoring the value of interdisciplinary collaboration in healthcare technology development. The software offers several advantages over paper-and-pencil LBT, including enhanced flexibility, improved efficiency, real-time feedback, and reduced risk of human error. This tablet-based LBT software is expected to provide an efficient and effective tool for assessing spatial perception.

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