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Due to a more physiological reproduction of the in vivo situation, liver‐on‐a‐chip devices in recent studies have shown higher sensitivity and accuracy for hepatotoxicity testing compared to traditional in vitro liver models. In this context, this work presents an original microfluidic device mimicking 3D hepatic cords organized radially, like in the liver lobule. Ten cell‐culture chambers seeded at a high density are disposed with a parallelized flow that emulates blood flow from the portal triad to the central vein in the liver lobule. Using this device, on‐chip differentiation of human HepaRG‐Hepatoblast (HepaRG‐HB) to HepaRG‐Hepatocytes (HepaRG‐HC) has been studied in terms of self‐organization capabilities, bile canaliculi formation and albumin expression. Our results indicate that due to the design of the cell culture chamber, which mechanically constrains tissue proliferation, and the physiologically relevant microfluidic flow condition used during tissue development, the HepaRG‐HBs in the device can proliferate, self‐organize, and spontaneously differentiate in a DMSO free medium forming long, directional bile canaliculi. On the contrary, under the same conditions, differentiated HepaRG‐HC is observed to aggregate without long bile canaliculi and form tissues resembling traditional HepaRG‐HC cultures. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The XY model is a simplified insulation model for transformers that aims to connect the frequency spectrum of major insulation, insulation paper, and oil. It enables the calculation of the paper's frequency spectrum, facilitating a quantitative evaluation of the transformer's insulation status. Given the scarcity of research addressing the accuracy of the XY model and its corresponding equivalent circuit, this paper investigates the accuracy of the XY model and conducts an in‐depth analysis of the error associated with its equivalent circuit. Firstly, the frequency spectrum of oil‐paper insulations based on the XY model with varying moisture content and structure configurations were measured, followed by the simulation of both the corresponding 2D‐coaxial and XY models. By comparing the results obtained from these simulations with experimental data on oil‐paper insulation, the accuracy of XY model is verified. Subsequently, two variants of the equivalent circuit of the XY model are derived by combining the oil, spacer, and paper differently, which denoted as Type I and II circuits. Finally, we analyzed and explained the errors present in these equivalent circuits compared with the XY model. Our findings show that the width‐thickness ratio of oil‐paper insulation is the most critical influencing factor, while moisture content and insulation structure have a less decisive impact. Notably, for general transformers, as the width‐thickness ratio is between 30 and 70, the relative error of the Type I circuit remains consistently below 0.3% across different frequencies. Consequently, the Type I circuit proves to be a more suitable representation of the equivalent circuit for the XY model in the context of general transformers. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper presents a semi‐passive smart contact lens platform for sensor and actuator applications. It focuses on design improvements made prior to human clinical trials involving basic considerations on comfort and safety, which are verified through animal studies. Observations of tissue temperature variation and post‐trial surgery examinations confirm that the 50 μW on‐lens wireless power delivery reduces the impact on tissue of previously reported SCL. Migration of wirelessly powered radio frequency identification (RFID)‐based passive SCL to semi‐passive systems is enabled with the proposed on‐lens power storage element. Furthermore, a switched capacitor converter extends the active time of the storage element and reduces electromagnetic influence. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The quartz crystal microbalance (QCM) biosensor is one of the devices that enables label‐free evaluation of biomolecular reactions. Commercial QCM biosensors have less than 10 channels for detection and are not suitable for the screening. The sensitivity of the QCM biosensor increases as the quartz thickness becomes thinner; however, the limit of thinning is 60–330 μm. In this study, applying micromachining technology, a QCM sensor array chip of 15 mm square that had 100 ultra‐thin quartz resonators (2.5 μm) that were operated wirelessly was developed. And we succeeded in detecting the resonance spectrum through the device evaluation. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper reports an ultra‐soft neural probe with a temporary high‐strength U‐section coating of polyethylene glycol (PEG) for the first time. Its fabrication is compatible with MEMS processes, and an ultrathin U‐section coating over the probe's back and sidewall is precisely formed by spinning and cold laser cutting. With this novel coating, the probe has both minimized cross‐sectional area and sufficient mechanical strength for low‐invasive penetration into the brain. Besides, the remained ultra‐soft deformable probe after PEG dissolution is expected to be the next generation of neural implants for chronic recording. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Aiming at the current control steady‐state error caused by sampling delay, parameters mismatch of direct‐drive permanent magnet synchronous motor (PMSM). This paper proposed a method of dual model predictive control (MPC) of direct‐drive PMSM based on sliding mode disturbance observer (SMDO). Deadbeat predictive current control (DPCC) is used for current loop, a SMDO is proposed to observe the system disturbance, the estimation is compensated to DPCC by feedback to decrease the current control steady‐state error. For speed loop, MPC with an internal model control observer (IMCO) can observe and compensate the load disturbance feedforward. The experimental results show that, the dynamic response speed of the proposed strategy is fast, the speed recovery time after sudden load torque is short, and the anti‐load disturbance performance and current tracking performance are effectively improved. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

YOLOv7 is one of the most effective algorithms for one‐stage detectors. However, when it is applied to pedestrian detection tasks in the industrial scene, it is still challenging for complex environments and multi‐scale changes of pedestrians. This paper proposes a new pedestrian detector for the industrial scene based on improved YOLOv7‐tiny and named as GP‐YOLO. First, the neck of YOLOv7‐tiny is replaced by RepGFPN structure, make full use of multi‐scale features to enhance the detection accuracy of objects with large‐scale changes. Second, a new gnconv branch is added to the feature fusion module, and the high‐order spatial interaction capability is introduced to further enhance the target detection accuracy. Finally, a lightweight method based on PModule is proposed, on this basis, a PConv bottleneck is designed to reduce the FLOPs and enhance the feature extraction. Experiments on a self‐made Industrial Pedestrian Data set show that before lightweight, the proposed algorithm achieves a 3.2% improvement in mAP@0.5:0.95 and a 3.7% improvement in Recall compared to the baseline YOLOv7‐tiny. After lightweight GP‐YOLO, compared to non‐lightweight, parameters and FLOPs are decreased by 26% and 23%, respectively, the mAP@0.5:0.95 is decreased by only 1.1% and the Recall is decreased by only 1.3%, which remains at a high level. Compared with baseline YOLOv7‐tiny, the lightweight GP‐YOLO has similar parameters and FLOPs, but the mAP@0.5:0.95 is increased by 2.1%, and the Recall is increased by 2.4%. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Wireless power transfer (WPT) technology can completely isolate the equipment from the power supply, and has been widely used. However, the transmission efficiency of WPT system is optimal only as the transmitting coil was completely aligned with the receiving coil. But in practical applications, the mobile devices are all dynamic system, and perfectly alignment of the coils is a very demanding condition. In order to solve this problem, the paper proposed a coil position adaptive adjustment control scheme of WPT system with lateral misalignment or angular misalignment. Firstly, the relationship between transmission efficiency and lateral misalignment and angular misalignment was analyzed. And the research results show that if there is a lateral misalignment between the coils, the transmission efficiency can be optimized by adjusting the angular misalignment. Secondly, based on the hill climbing algorithm, a coil position adaptive adjustment control method was proposed. Finally, a coil position adaptive adjustment WPT system experimental platform was built, and the experimental researches are carried on. The results of the experiment show that as the transfer distance is 0.10 m and the lateral misalignment is 0.12 m, the transfer efficiency can be increased from 38.38% to 55.61% through the proposed control scheme. And the results verify the feasibility and effectiveness of control scheme proposed in the paper. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The accumulation of snow is one of the essential reasons for the significant decrease in the power generation efficiency of PV stations in winter. For this reason, this paper firstly provides a detailed review of the current research into the physical processes and shedding reasons for the natural melting of snow on PV module surfaces. Then, several common techniques to promote snow and ice melting on PV surfaces are discussed, and the feasibility and shortcoming of ultrasonic technology in removing high‐density snow and ice are analyzed in detail. Finally, this paper proposes two snow sensing technologies for PV modules, namely, image processing method and interdigital capacitance method. Among them, the image method based on fixed camera and UAV detection is more suitable for wide area PV power stations, while the interdigital capacitance method is helpful in obtaining snow characteristic parameters, such as icing type and LWC. The relevant research has certain reference significance for PV power stations to formulate a more reasonable snow removal plan and power generation forecast. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper proposes an effective control synthesis strategy to stabilize grid forming converters in the presence of disturbances. The conventional control system for a grid forming converter is based on paralleled and cascaded proportional‐integral (PI) controllers, which are widely used in the industry due to their simplicity and reliability. However, the sequential adjustment of PI gains in different control loops, without consideration of dynamic interconnections limits their performance and capability. To address this limitation, the present paper introduces a control design method based on static output feedback theory. The proposed control scheme reduces the dynamic control design problem to an effective gain scheduling problem. In the proposed methodology, without removing the existing practical control structure, its dynamic parts are moved to the open‐loop system, and simultaneous scheduling of all remaining control gains is achieved during one control design process. MATLAB simulations were conducted to evaluate the performance of the designed control system, and compare it with the conventional control one in terms of step response characteristics. The results demonstrate the superiority of the proposed controller, ensuring system stability and exhibiting improved performance. The proposed control framework provides several advantages, including keeping stability in various disturbance conditions, simultaneous tuning of all control parameters, and no need to change the existing simple control structure. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Coils are designed to have impedance characteristics appropriate for any use of the sensors, analog circuits and so on. The impedance characteristics of a coil depends on the coil shape and used materials, and these factors make coil design difficult. Therefore, we proposed a convenient method to obtain the impedance characteristics of a coil by theoretical calculation of the inductance, resistance, and capacitance. The difference between the calculated and measured values was within 15%, which demonstrated the usefulness of the proposed method. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This study aims to enhance the accuracy of rail‐lane extraction, which determines the rail lane and its background at a pixel‐wise level from an ego‐perspective image captured by the front camera of a train. For this purpose, cutting‐edge deep neural network (DNN)‐based semantic segmentation models, MANet and UNet++, were applied. In addition, a method that effectively enlarges the rail lane extracted by DNN‐based segmentation was proposed based on thoroughly analyzing the issues of DNN‐based segmentation. Our experiment, which employed 601 ego‐perspective images, demonstrated that the proposed method using the cutting‐edge DNN‐based segmentation method increased the balanced accuracy by 6.66% compared with the conventionally employed ERFNet in the literature. Further discussions and useful analyses are presented herein. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Owing to the mass penetration of renewable energy (RE) in Japan, the replacement reserve for feed‐in tariff (RR‐FIT) was introduced in 2021. To promote the further introduction of RE, we attempted to provide reserve power value to the balancing market by controlling the headroom of photovoltaic (PV) power with a PV power plant as a research subject. At the planning stage, the information available is the predicted value, and PV prediction error always occur on the day. Therefore, in this research, we proposed an algorithm to determine the absorption of prediction errors headroom in PV output, thereby maximally reducing negative imbalance. In addition, we developed a statistical model, SVR model, and combined models to calculate and compare the number of imbalance spots and amount of imbalance. Accordingly, the proposed methods can significantly reduce imbalance compared to planning with predicted values, without setting the headroom of prediction errors. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Frequency‐domain electromagnetic (FDEM) instruments are effective tools for detecting underground electrical abnormal targets. However, due to the influence of various noises in the detection process, would lead to l poor signal‐to‐noise ratio of the system and would ultimately affect the detection accuracy. And FDEM detection systems have a defined measuring range. Excessive noise will lead to saturation of the system acquisition and distortion of the measurement. Because of the above problems, an acquisition technique for the FDEM receiving system is proposed to achieve noise suppression in the detection process. The scheme proposes a multi‐frequency LC filtering circuit to optimize the analog signal acquisition module of the receiver system. The circuit converts the measured voltage signal into a current signal, improving the system's immunity to interference. At the same time, the noise of non‐target frequencies in the measured signal is suppressed, avoiding saturation of the receiving system acquisition, and realizing high signal‐to‐noise acquisition of multiple target frequencies. First, the principle of circuit design is analyzed, and the design flow of circuit parameters is proposed. Further, the validity of the design is verified via simulation results. Finally, the optimization scheme is validated with an actual circuit. The results show that for the measurement environment set in this paper, this optimization scheme can suppress the noise of non‐target frequency in the measured signal, so that the noise amplitude can be reduced by more than 90%, and the signal‐to‐noise ratio of the filtered signal can be improved by 23.35 dB. This study helps to facilitate FDEM instruments to achieve high signal‐to‐noise ratio detection. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

To improve the pulse width modulation (PWM) harmonic suppression effect of the three‐phase VSI‐fed PMSM system, this paper proposed a novel random switching period (RSP)‐Space Vector Pulse Width Modulation (SVPWM) technique for the three‐phase power converter. First, the proposed technique replaces the 10‐bit linear feedback shift register pseudorandom number generator (LFSR‐PRNG) with a Tiny Mersenne Twister (MT)‐PRNG to quickly generate high‐quality pseudorandom number sequences. Then, to reduce the sampling error caused by the current ripple, this paper analyzes the sampling timing under different modulation techniques. Based on the interrupted update mechanism of the Infineon AURIX‐TC264, the variable frequency sampling of the RSP‐SVPWM technique is implemented to ensure the best sampling of the motor phase current. Finally, the simulation and experimental results show that the proposed technique can effectively disperse PWM harmonic energy. Meanwhile, the RSP‐SVPWM technique based on variable sampling frequency effectively improves the phase current quality of the PMSM system. The proposed technique shows great potential for suppressing PWM harmonics in integrated PMSM systems. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In the design of high‐power microwave (HPM) waveguide array of longitudinal shunt slots, the mutual coupling of slots in different waveguide can badly decrease the capability of wide‐angle scanning of array. An L‐band HPM waveguide array of longitudinal shunt slots is designed. The choke groove was designed to restrain the mutual coupling of slots of the HPM array antenna. The result of simulation verified that the scanning angle with the gain of antenna decreased of 3 dB of array without choke groove structure is only 25°, and that is 35.0° with choke groove structure. The wideband of active reflection of array can be improved by the choke groove structure. The result of experiment also verified that the slot array antenna provided 30° beam steering with a gain reduction of 1.8 dBi and the power‐handling capacity of the array with the choke groove is greater than 1.5 GW with width of pulse of 42 ns. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Recently, a retail industry has trended to adopt automatic checkout systems for enhancing customer sales. Typically, an automatic checkout system employs an object detection technique (i.e., image processing) based on a commonly used deep learning model (e.g., Faster R‐CNN and YOLO) that has been trained for items. Therefore, it takes much time to relearn the model whenever an item is added to the system. To save the relearning cost, we propose a novel automatic checkout system reducing the relearning cost of an additional item. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Collaborative robots, that work alongside humans, will be an indispensable part of the future workforce. Proximity skin sensors on collaborative robots help them avoid collisions with people and other objects. Several skin sensors that fit the shape of the robot surface have been developed. As the shape of each robot varies, developing sensors for each of them is expensive and inefficient. In this study, we propose a string‐like time of flight (ToF) sensor module that can be easily mounted on the surface of a robot. The prototype sensor module consists of six ToF sensors, and each module can be interconnected. The module can detect the distance of an object and its position before making contact. Articulated string‐like modules are wrapped around the surface of the robot to detect objects at a given proximity range around the robot. The movement of the robot can be controlled based on the measurement data obtained by the sensor. Therefore, these proximity skin sensor modules can ensure safety and workability of the robot by preventing unwanted contact between the robot and objects. Thus, the sensor can be used as skin sensors in collaborative robots. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In order to improve the dynamic and steady‐state performance of the finite control set model predictive torque controlled surface‐mounted permanent magnet synchronous motor drive system, a novel finite control set model predictive torque control (FCS‐MPTC) with different dynamic and steady‐state control schemes is proposed in this paper. When the SMPMSM drive system operates at transient state, the optimal basic voltage vector of inverter is the vector that minimizes torque tracking error, the proposed FCS‐MPTC achieves fast dynamic response based on the optimal torque control. When the system operates at steady state, the relative importance of torque to the stator flux amplitude is calculated based on the quantitative analysis of minimum staggered errors between motor torque and stator flux amplitude control objectives, then the priority weighting factors based on the relative importance are determined online adaptively, the optimal control of motor torque and stator flux amplitude is achieved simultaneously. Finally, the comparison of the experimental results of proposed FCS‐MPTC with different control methods is implemented and research conclusion is shown. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In order to mitigate the negative impact brought by the large‐scale grid connection of EVs, it is highly significant to study the optimal charging scheduling strategy of EVs. In this paper, a multiobjective optimization model of ordered charging and discharging with the participation of distribution network operator (DNO), charging station operator (CSO) and EV users is established, which maximize the interest of three parties. At the same time, the real‐time price (RTP) based on the change in load rate is designed and compared with the time‐of‐use (TOU) price model to analyze the impact of both on the interests of all parties. At last, the sparrow search algorithm (SSA) is introduced and three improvements are made. The results demonstrate that different charging modes of EVs and charging price models will affect the balance of interests of the three parties, while the improved SSA performs better under different users' response rates. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In recent years, the demand for quantifying the five senses has increased in the industrial and medical fields. In particular, the sense of touch is a complex sensation consisting of contact force, sliding force, and cold‐warm sensation. The cold‐warm sensation is perceived by the difference in heat transfer between the object and the skin, and the difference in the heat capacity of the object. In our previous research, we developed a MEMS tactile sensor that can measure contact force, sliding force, and cold‐warm sensation with a single sensor. However, the measurement of the cold‐warm sensation requires a long measurement time to stabilize the temperature and relatively high‐temperature conditions of 40°C or higher. In this study, we report on a method for measuring the cold‐warm sensation at a temperature similar to that of a human fingertip. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Population‐based evolutionary algorithms are suitable for solving multi‐objective optimization problems involving multiple conflicting objectives. This is because a set of well‐distributed solutions can be obtained by a single run, which approximate the optimal tradeoff among the objectives. Over the past three decades, evolutionary multi‐objective optimization has been intensively studied and used in various real‐world applications. However, evolutionary multi‐objective optimization faces various difficulties as the number of objectives increases. The simultaneous optimization of more than three objectives, which is called many‐objective optimization, has attracted considerable research attention. This paper explains various difficulties in evolutionary many‐objective optimization, reviews representative approaches, and discusses their effects and limitations. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Point‐of‐interest (POI) recommendation has always faced serious data sparsity problem. Most of the existing POI recommendation methods do not consider the bidirectional relationship between the user‐preference for locations and the location‐ attractiveness to users in the original dataset when solving the sparsity. For this problem, a point‐of‐interest recommendation method based on bidirectional matrix and deep belief network (POI_DBNBM) is proposed in this paper. Specially, from the perspectives of users and locations, we first construct two different matrices with bidirectional relationship by mapping the original dataset, and we use deep belief network (DBN) with strong learning ability to predict the two matrices. Then, a local–global weight optimization method is developed to weight and fuse the two result matrices obtained by DBN, so as to achieve the more precise user's rating prediction matrix for locations. The abundant experimental studies and evaluations are conducted on FourSquare dataset. Results are encouraging and better than those previously reported on the dataset. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This study has designed a set of motor operating devices for a 126 kV vacuum circuit breaker (VCB) to improve its reliability and controllability. A finite‐angle permanent magnet brushless motor (FAPMBM) with a multi‐slot stator structure and a dovetail rotor structure has been designed based on the torque and speed requirements of the motor. These requirements were determined by a dynamic analysis of the operating device and its short‐time, finite‐angle working characteristics. The work performance of the prototype motor has been evaluated in an online experiment with a 126 kV VCB, and based on this, a segmented control method has been designed. The motion process of the operating device has been divided into four stages in combination with the output torque demand of the driving motor. At each stage, the output torque of the motor has been changed dynamically to prevent contact collision, shorten the pre‐breakdown time, and make the circuit breaker work more reliably. The results show that the FAPMBM can meet the operating time and speed requirements of the interrupter for the operating device. In addition, the segmented control method improves the work reliability and optimizes the movement of the operating device, which helps the circuit breaker work intelligently. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this paper, a new dual mode blind equalization method using neighborhood symbol‐based decision and decision‐directed (NSBD‐DD) algorithm is proposed to equalize the satellite communication signals. The proposed algorithm adopts the combined cost function to employ the advantages of symbol decision algorithm and the decision‐directed algorithm, which can further improve the universality of the proposed algorithm. Compared with the conventional blind equalization algorithm, the compensation ability of intersymbol interference and convergence speed of the proposed algorithm can be improved simultaneously. To verify the performance of the proposed algorithm, the computer simulation is performed, and the simulation results show that the residual intersymbol interference of the 64QAM signals can be decreased to −50 dB under the satellite channel, which has 30 dB lower than multi‐modulus algorithm (MMA), 26 dB lower than NSBD algorithm, and 10 dB lower than SBD algorithm. And compared with SBD algorithm, the number of iterations required for the NSBD‐DD algorithm can be decreased from 8000 iterations to 6000 iterations, which convergence speed is increased by 25%. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Dynamic neural networks (DNNs) are widely used in data‐driven modeling of nonlinear control systems. Due to the complexity of the actual operating nonlinear power systems, rigorous dynamic models are always unknown. DNNs can focus on methods that only use input and output information to establish accurate dynamic models and reduce noise in measured data, which is called data‐driven modeling. The core of the DNN is the feedback with memory function. This paper analyzes the traditional Elman neural network (ENN) and nonlinear auto‐regression with exogenous input (NARX) neural network with different structure feedback structures, and proposes a full feedback dynamic neural network (FF‐DNN) with exogenous input. Eight different kinds of neural networks (including ENN, NARX, etc.) are compared and analyzed. The eight kinds of neural networks are applied on the experimental data of the DC‐AC inverter and the power system of Zhejiang Juchuang Smart Technology Company Park in Wenzhou. The experimental results are used to compare the performance of the data‐driven models established by eight different kinds of neural networks under different noise conditions, verify the robustness and generalization performance of dynamic data‐driven modeling based on FF‐DNN, and demonstrate the feasibility and effectiveness of FF‐DNN in actual power systems. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper presents a novel frequency compensation scheme for the stability of low dropout regulator (LDO). The proposed compensation scheme introduces a zero in the voltage regulation loop to enlarge gain and phase margin at high‐frequencies. As a result, high open‐loop‐gain and improved load regulation performances are achieved, and a particular resistor is introduced in the compensation structure to cancel the voltage drop originating from cable resistances at the output to further improve the load regulation performance. The proposed LDO with wide input/output range and high‐power supply rejection is designed and implemented in a 180 nm CMOS process. The LDO operates with an input voltage range of 4–16 V, an output voltage range of 1.5–5 V and an output current range of 0–1000 mA. High open loop gain and high bandwidth are achieved, and the simulated performances of load regulation and line regulation are less than 32 μV/mA and less than 3 mV/V over the whole operation range, respectively. The on‐chip compensation capacitor required by the compensation module is only 1.8 pF. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This study demonstrates the mapping of input/output (I/O) data of Central Research Institute of Electric Power Industry's Power System Analysis Tool (CPAT) with the Common Information Model (CIM) and the setting of the multiplicity of attributes and associations. The mapping describes which CIM classes defined in IEC 61970‐301 Edition 7.0 and IEC 61970‐302 Edition 1.0 correspond to which I/O data of CPAT. In addition, the multiplicity of their attributes and associations is determined by requirements of the I/O data of CPAT. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Vibration power generation using environmental vibrations to generate electricity has attracted attention as a sustainable independent power source such as wireless sensors placed under vibration. However, for efficient power generation, the resonant frequency of the vibration power generator must be automatically adjusted to the environmental vibrations. To achieve it, the author's group proposes installing a variable capacitance in the device and adjusting its capacitance by extremum seeking control. Therefore, this study proposes a generator configuration "twin generators" and a new extremum seeking control. Compared to the method employing conventional extremum seeking control, the proposed method increases power generation efficiency under damped vibration excitation, even when the vibration's amplitude and frequency change randomly. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Job shop scheduling problem (JSSP) is one of the well‐known NP‐hard combinatorial optimization problems (COPs) that aims to optimize the sequential assignment of finite machines to a set of jobs while adhering to specified problem constraints. Conventional solution approaches which include heuristic dispatching rules and evolutionary algorithms has been largely in use to solve JSSPs. Recently, the use of reinforcement learning (RL) has gained popularity for delivering better solution quality for JSSPs. In this research, we propose an end‐to‐end deep reinforcement learning (DRL) based scheduling model for solving the standard JSSP. Our DRL model uses attention‐based encoder of Transformer network to embed the JSSP environment represented as a disjunctive graph. We introduced Gate mechanism to modulate the flow of learnt features by preventing noise features from propagating across the network to enrich the representations of nodes of the disjunctive graph. In addition, we designed a novel Gate‐based graph pooling mechanism that preferentially constructs the graph embedding. A simple multi‐layer perceptron (MLP) based action selection network is used for sequentially generating optimal schedules. The model is trained using proximal policy optimization (PPO) algorithm which is built on actor critic (AC) framework. Experimental results show that our model outperforms existing heuristics and state of the art DRL based baselines on generated instances and well‐known public test benchmarks. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Since anomalies are usually caused by changes in shape and amplitude in time series data, and most of the interval‐based methods utilized appear in the literature from a global perspective to detect anomalies. Nevertheless, the anomalies are also usually caused by local changes in shape and amplitude. Following these limitations, an enhanced interval‐based approach based on the interval information granules with the principle of justifiable granularity, viz., the EIA method, is formulated in this study for anomaly detection. First, the interval information granules are produced separately from the global and local perspectives in an abstracted manner on the basis of this principle. An interval‐based similarity measurement algorithm is then designed based on the abstraction results to calculate the anomaly scores from the various interval information granules for anomaly detection. Compared with classical methods, the proposed approach exhibits better performance in terms of data anomaly resolution and detection accuracy, which have been verified and supported in much of real‐world data. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A novel parameter estimation method of frequency hopping spread spectrum (FHSS) signal is proposed. The observed signal is divided into multiple segments and forms an observed matrix, performing FFT on the observed matrix with different segment lengths to obtain the corresponding spectrum matrix. By analyzing the convergence characteristics of the spectrum matrix, the estimation of the symbol period is realized, on this basis, the symbol‐frequency distribution is obtained and its projected spectrum in Frequency‐Amplitude plane is further obtained to select the candidate frequencies. The matrix composed of multiple single frequency signals is constructed according to the candidate frequencies and multiplied with the observed matrix under the segment length of symbol period, then the number of symbols per hopping duration is estimated according to the matrix multiplication result, so as to realize the estimation of the hopping duration, and finally the real hopping frequencies and hopping sequence can be found out from the candidate frequencies. Simulation results are presented to indicate that the proposed method has good estimation performance especially under the condition of low SNR. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The loop operation of distribution lines is expected to reduce power loss and increase the introduction of distributed energy resources as solar power generators and storage batteries. A significant problem during the failure of a section of a distribution line in loop operation is the extension of the failure to other sections due to the wideness of the power supply network area. Currently, there are no methods to easily identify a faulty section using the failure waveform during the loop operation of distribution lines and ground faults; consequently, short‐circuits or disconnections still occur. Therefore, when operating a loop of distribution lines, it is necessary to identify and isolate a faulty section. To solve this problem, we investigate and propose a method to identify the faulty section based on the voltage and current values measured using a switchgear with sensor at the waveform level. By applying the proposed method to identify and isolate faulty sections during distribution line loop operation, power can be transmitted to sections where no fault has occurred at an early stage. The proposed method has a significantly reliable fault detection capability and will help improve the stability of the power supply during loop operation. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this work, we investigated strength variations of the ventriloquism effect when the loudspeaker's position was indicated to the subject. The ventriloquism effect is an audiovisual cross‐modality in which a sound is heard from the position of an image, even though the sound and image are presented at different locations. Previously, this effect has been studied under conditions where the sound location is not revealed. In contrast, this paper proposes measuring the ventriloquism effect using a single loudspeaker displayed as a 3D scanned image in the background of a virtual reality (VR) image. The angular discrimination threshold (the perceived angle of disparity between the sound and the image shifted horizontally) was employed to evaluate the ventriloquism effect. The resulting ventriloquism effect was compared to the effect noted in a previous study, where measurements were conducted without revealing the loudspeaker's position to the subjects. The results indicate that revealing the loudspeaker's position emphasizes the ventriloquism effect. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The current transformations in the training model have required Higher Education to reconsider the professional profile models. In this effort, the curriculum in the Electrical Engineering career is perfected, in which the essentiality of the contents is essential to reduce training time and achieve higher levels of independence and leadership of the student. For this, it is important to take advantage of the advantages offered by Information and Communication Technologies in the educational field, so the objective of the article is to propose programming as a method to improve the teaching-learning process of electrical engineers through the development of a graphical interface application derived from Scilab. The research was developed in the Electrical Engineering career with a sample of 70 4th year students, the results obtained corroborate the importance of using the proposed method. [ABSTRACT FROM AUTHOR]

A novel duty‐cycle‐sensing overload detector for DC‐DC converter is proposed in this paper. Firstly, the theoretical analysis is conducted to reveal the susceptibility of the conventional overload detectors to temperature variation and the input/output‐voltage change of the DC‐DC converter. Then, the schematic of the novel duty‐cycle‐sensing overload detector is presented and its operation principle is analyzed. Thanks to the time register, the proposed detector generates a theoretically voltage‐and‐temperature‐insensitive threshold duty cycle, compares it with the real‐time duty cycle of the converter's PWM signal, and announces an overload event if the real‐time duty cycle exceeds the threshold. Finally, a prototype of a BUCK DC‐DC converter including the proposed detector and a conventional current‐sensing overload detector is constructed and measured. As the measurement results show, the threshold duty cycle only varies by about 2.4% as the temperature changes from 0 to 90 °C while the threshold voltage of the conventional current‐sensing detector changes by about 4.6%. The proposed detector can keep effective even the temperature rises to 90 °C while the conventional current‐sensing detector can work at a temperature no higher than 85 °C. Without circuitry modification, the proposed detector correctly senses the overload event as the DC‐DC converter's output voltage changes in a range of 2.1–2.9 V while the conventional one loses its effectiveness if the output voltage is set higher than 2.54 V. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A new three‐phase two‐switch voltage clamping buck Power Factor Correction (PFC) is presents in this paper. The principle and equations of operations are described in detail. Based on the volt‐second balance principle of input inductance in the new converter, this paper gives the design method of the circuit's key components, with voltage and current stresses analyzed. On the basis of the theory above, a prototype with parameters of a 5 kW is designed. Problems of extremely high switch peak voltage stress in the conventional one are solved. The manufacturing cost of high power three phase rectifier has been significantly decreased. A 5 kW experimental prototype with unity power factor, 4.4% input line current THD, 200 Vdc output, and system efficiency of 96% at full load under 380 Vrms input line‐to‐line voltage has been successfully implemented. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Future labor forces are anticipated to include collaborative robots that work alongside humans in the same environment. Proximity and tactile sensors are among the most important devices for collaborative robots to operate safely. In this paper, we propose a proximity and tactile sensor for a collaborative robot that combines multiple time‐of‐flight (ToF) sensors and a self‐capacitating proximity and tactile sensor. ToF sensors can detect the distance to an object and have a long measurement range. However, at close distances, their detection accuracy deteriorates, and blind spots may likely not be detected. Conversely, the self‐capacitance proximity and tactile sensor detect objects within the blind spots of ToF sensors and contact conditions because the sensor can detect an object before and after contact, being highly sensitive in the proximity range. In the proposed sensor, the electrodes of the self‐capacitance are enlarged, and multiple ToF sensors are used to expand the measurement range and reduce blind spots. A prototype sensor was seamlessly able to measure objects from approximately 400 mm to contact conditions. In addition, the robot arm with the prototype sensor could be controlled in real time using the measured data of the sensor. Therefore, we believe that the proposed sensor can be potentially used as a proximity and tactile sensor for collaborative robots. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper gives a novel method to design less‐conservative robust PID control systems. The partial model matching method is a design method for PID control systems. That is a method to design a control system that matches a reference model as closely as possible. This method does not guarantee robust stability of a PID control system because it is assumed that there are no uncertainties on the coefficients of the lower‐order terms of the plant. Therefore, in our previous work, a robust design method based on the partial model matching method was proposed. However, the drawback of this conventional method is that the results of stability analysis are conservative. In this paper, we aim to reduce the conservativeness caused by the conventional method. To achieve this goal, we use a robust stability analysis method based on the Cremer–Leonhard–Mikhailov criterion and the mapping theorem. Moreover, we also propose a new method to update the value of a design parameter. A numerical example shown in this paper implies that the conservativeness is reduced by the proposed method. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Stimulus reconstruction decodes the listener's auditory attention through the greater neural tracking of the attended speech over the unattended stream. While acoustic features of speech are vital to the listening task and comprehension, very few studies have analyzed the effects of acoustic features of speech on stimulus reconstruction. This paper investigates approaches of stimulus reconstruction, where correlations between the neurally decoded and actual speech envelopes are calculated from specific speech segments, varying in transient levels as measured by spectral transition measures. Additionally, two methods of calculating correlations were adopted enabling analysis of the effects of relatively lower and higher frequency components of the speech envelope. Correlation after concatenation analysis showed that STM level of only the attended speech affected decoding performance, hinting at a top‐down attentional effect. A bottom‐up effect of salient aspects of speech momentarily dominating neural entrainment was also inferred from the weighted mean of multiple correlations. Future studies on the link between acoustic features of speech and its corresponding neural tracking behavior are suggested. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In the actual power grid environment, there are severe class imbalances in the data sets of various monitoring systems. The existing deep learning methods are highly dependent on the training data sets, and it is difficult to mine the minority sample features in the imbalanced data sets, resulting in Classification recognition accuracy is severely limited. This paper takes the voltage sag as the research object, and proposes a dataset enhancement method based on an improved balanced generative adversarial network. This method combines the advantages of autoencoder and generative adversarial network, learns the public knowledge in the data set through the initialization training of autoencoder, and uses the majority class sample features to assist in generating minority class samples. In addition, an embedding layer is introduced into the self‐encoder architecture to add label information to the eigenvectors, which solves the problem of strong coupling between the distribution of voltage sag eigenvectors and improves the generation effect of samples. At the same time, the Wasserstein distance optimized by the gradient penalty term is used to guide the model adversarial training, which overcomes the problems of vanishing gradient and mode collapse of the original model. Through experimental analysis, the model can fully extract the features of minority samples under unbalanced data sets, ensure the distribution consistency between generated samples and original samples, and take into account the authenticity and diversity of generated samples, which can effectively improve the recognition effect of deep learning model on minority classes and improve the overall recognition accuracy. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This study aims to develop a method that can detect the areas of Japanese texts that are difficult to read on a PC screen by analyzing eye movements. An effective method for detecting the areas of text that are difficult to read is to create a heatmap and consider the areas where the eye stays for longer than a fixation duration threshold (threshold). Usually, the threshold is determined through a 50 ms step search. However, since the eye stay time (fixation duration) for difficult‐to‐read text is longer than the fixation duration when reading smoothly, it is expected that steps that last longer than 50 ms are more effective at detecting the threshold. Furthermore, there are individual differences in the speed at which we comprehend text. In this study, we proposed a method that considers both the efficient search and individual differences among each subject. The experimental results showed that the threshold determined by the proposed method is more useful than the thresholds of 1000 and 800 ms that were used in a previous study, as well as the usual fixation duration of 250 ms. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The brain encodes various information through the interaction between macro‐scale phenomena such as Local Field Potential and micro‐scale phenomena such as individual neuron action potential time series. However, the interaction between micro‐ and macro‐scale phenomena that affects episodic memory remains unexplained. We propose a new mathematical framework to predict the parameter conditions under which theta phase precession occurs by constructing models that reproduce the micro‐ and macro‐scale phenomena separately and deriving their phase equations. It was found that phase locking or phase shift between the micro‐scale phase ϕmicro and the macro‐scale phase ΦMacro can reproduce different storage schemes. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The auxiliary resonant snubber‐based converter (ARSC) has the advantages of low dead‐time effect and low switching loss. However, the auxiliary switches suffer from high reverse recovery loss and high reverse recovery current in high‐switching frequency application. Thus, the ARSC with saturable inductor is proposed to solve the problem above. In this paper, the operating principle of ARSC with saturable inductor is analyzed, and the duty cycle operating range that can realize ZVS in the full load range is deduced. The reverse recovery model of the auxiliary switching device body diode is established to analyze the circuit parameters' influence. Then, the influence of the saturable inductor on the reverse recovery peak current and reverse recovery loss is analyzed. Based on the analysis results, the saturable inductance parameters are designed. Finally, based on the experimental platform of the ARSC, the effectiveness of the proposed method is verified. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A method for detecting atrial fibrillation (AF) from electrocardiogram (ECG) measured by a 24‐hour Holter electrocardiograph (Holter‐ECG) is proposed using convolutional neural network (CNN). In the preprocessing stage, artifacts and noises on Holter‐ECG are removed by a bandpass filter. The detection method consists of two stages: extraction of abnormal waveforms using one‐dimensional CNN trained with segmented ECG waveform and its spectral entropy, and identification of AF using two‐dimensional CNN trained with segmented ECG spectrogram. A total of 47 520 datasets obtained from Holter‐ECG were prepared, and used for training at both CNN stages. Newly prepared (untrained) datasets of 24‐hour Holter‐ECG of 10 subjects and MIT‐BIH databases are tested, and the proposed method showed sufficient performance for detecting AF, with the accuracy of approximately 90%. This result indicates the feasibility of the proposed method. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Driven by deep learning, great breakthroughs had been made in the field of target detection. Small target detection algorithms were widely used in industry, agriculture and other fields. But the small target had few available features and the loss of small target detail information in feature extraction. So it led to the low accuracy of the small target detection algorithms. In this paper, we proposed DBF‐YOLO algorithm based on the classical YOLOV5. The classical YOLOV5 algorithm with high speed. The detection speed of the minimum model could reach 24 ms. However, the deep network structure led to the low detection accuracy of small targets. Our proposed DBF‐YOLO algorithm was an improvement on the problem of small target information being lost. The main contributions of this article were mainly: First, a shallow feature extraction network was introduced in P1 layer, more details of small targets could be well retained. Second, by adding the feature fusion network of shallow feature map and the detection output part in the FPN + PAN layers, the algorithm's accuracy and generalization ability were significantly enhanced. Compared to YOLOV5, the performance of the DBF‐YOLO algorithm was significantly improved. On the validation set, mAP@0.5 and mAP@0.5:0.95 were increased by 8.80 and 5.90%, respectively. Recall was increased from the initial 34.50–41.80%. Precision was increased from initial 44.20 to 50.70%. On the test set, mAP@0.5 and mAP@0.5:0.95 were increased by 6.40 and 3.90%, respectively. Recall was increased 5.10%. Precision was increased 6.60%. Experiments had shown that the improved algorithm achieved good results in accuracy. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this paper, we investigate power adjustment for multi‐agent systems in a wireless network where communication range is limited. The approach in which communication range is dynamically changed is utilized so as to save power consumption. However, since drawback of this approach is that agents cannot expand their communication range, it causes that communication between agents tends to be disconnected. To overcome this problem, we propose two power adjustment methods. In the first method, communication range is temporarily expanded in accordance with the number of neighboring agents. In the second method, agents change their communication range by using information on the total number of agents and relative distance between an agent and the farthest neighboring agent. Through numerical simulation, we show that the proposed power adjustment methods reduce power consumption and improve success rate for consensus. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The separation of tiles from buildings degrades the aesthetic appeal of buildings and may result in structural failure. Therefore, tiles should be inspected periodically. However, manual inspections are expensive and require qualified experts. In this study, voids corresponding to tile separation were detected in a concrete specimen using nondestructive inspection based on electromagnetic wave detection. Furthermore, wave reflection models of healthy and defective tiles were created, and the effects of the void plane size on the reflection of defective tiles were considered. The correlation between the void plane size and the reflection intensity difference integral value was verified through multilayer scanning using these models. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A novel sliding mode observer for speed estimation in sensorless induction motor drives at zero and low speed is proposed in this paper. First, aiming at the poor stability when the induction motor runs at low speed, analyze the reasons of the poor stability and a new feedback gains design method is proposed. Second, for the problem of ignored flux error in speed estimation which cause speed error at low speed, a new compensation method is put forward, which can improve the accuracy of speed estimation in the dynamic and steady state of the system. Meanwhile, a continuous function is given which can replace sign, to restrain the chattering problem of sliding mode observer. Detailed simulation results are given showing the operation at zero and low speed, the results prove the effectiveness of the proposed sliding mode observer. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]