Research

37 pages, 16519 KiB

Open AccessArticle

Development of Single-Phase Synchronous Inverter for Single-Phase Microgrid

by Naoto Yorino, Yoshifumi Zoka, Yutaka Sasaki, Shinya Sekizaki, Mitsuo Yokonuma, Takahiro Himuro, Futoshi Kuroki, Toshinori Fujii and Hirotaka Inoue

Electronics 2024, 13(3), 478; https://doi.org/10.3390/electronics13030478 - 23 Jan 2024

Viewed by 559

Abstract

The work is based on a collaboration between Hiroshima University and Kure KOSEN College. This paper presents the design concept, hardware, and applications of a single-phase synchronous inverter (SSI), a specially designed grid-forming inverter (GFM) for single-phase micro-grid (SMGs). The SSI is designed [...] Read more.

The work is based on a collaboration between Hiroshima University and Kure KOSEN College. This paper presents the design concept, hardware, and applications of a single-phase synchronous inverter (SSI), a specially designed grid-forming inverter (GFM) for single-phase micro-grid (SMGs). The SSI is designed for the conventional 100/200 V distribution network and is based on the concept of “Non-Interference Core (NIC) dynamic model”. Novel contributions of this paper are: (1) A root mean square (RMS) model of NIC-SSI was developed, combined with the conventional power system model, and verified through the comparison with the hardware-in-the-loop (HIL) simulation and SSI hardware experiments; (2) using the developed RMS simulation tool, the stabilization effect of the SSIs was investigated in condition under which the SSIs are massively installed in a distribution system; (3) off-grid SMG operations using SSIs under various ill-conditioned loads were demonstrated. The results show that the SSI has the considerable ability of grid stability enhancements for frequency, transient, and small-signal stabilities. The proposed SMG using SSIs is promising. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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17 pages, 3039 KiB

Open AccessArticle

The Development of a Compact Pulsed Power Supply with Semiconductor Series Connection

by Shohei Zaizen, Kyohei Asami, Takashi Furukawa, Takeshi Hatta, Tsubasa Nakamura, Takashi Sakugawa and Takahisa Ueno

Electronics 2023, 12(21), 4541; https://doi.org/10.3390/electronics12214541 - 04 Nov 2023

Viewed by 1072

Abstract

In this study, high-voltage switching was performed by connecting semiconductors in series. By employing Snubber circuits and voltage divider resistors for each semiconductor, the destruction of the semiconductors was prevented. Additionally, a pulse transformer was installed between the function generator and the photocoupler [...] Read more.

In this study, high-voltage switching was performed by connecting semiconductors in series. By employing Snubber circuits and voltage divider resistors for each semiconductor, the destruction of the semiconductors was prevented. Additionally, a pulse transformer was installed between the function generator and the photocoupler to isolate the gate circuit, preventing electrical discharges in the circuit and enabling operation at an output voltage of 10 kV and an operating frequency of 200 Hz. The temperature of the semiconductors increased with the increase in operating frequency, which was counteracted by connecting charging resistors and capacitors to limit the current to the semiconductors. As a result, operation at 430 Hz became possible. Furthermore, a saturable inductor (SI) was connected to enable continuous operation. The SI delays the rise of the current and creates a phase difference, thereby reducing the power consumption of the conductor and mitigating the temperature rise, enabling continuous operation at 300 Hz. Moreover, by increasing the number of semiconductor series stages to six, an output voltage of 20 kV was confirmed in tests. By using two semiconductor series circuits, the pulsed power supply that can be changed to any pulse width was also created. As a result, output voltages with arbitrary pulse widths from 5 μs to 30 μs were confirmed. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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18 pages, 3432 KiB

Open AccessArticle

High Accuracy and Wide Range Recognition of Micro AR Markers with Dynamic Camera Parameter Control

by Daisuke Haraguchi and Ryu Miyahara

Electronics 2023, 12(21), 4398; https://doi.org/10.3390/electronics12214398 - 24 Oct 2023

Viewed by 1043

Abstract

This paper presents a novel dynamic camera parameter control method for the position and posture estimation of highly miniaturized AR markers (micro AR markers) using a low-cost general camera. The proposed method captures images from the camera at each cycle and detects markers [...] Read more.

This paper presents a novel dynamic camera parameter control method for the position and posture estimation of highly miniaturized AR markers (micro AR markers) using a low-cost general camera. The proposed method captures images from the camera at each cycle and detects markers from these images. Subsequently, it performs iterative calculations of the marker’s position and posture to converge them to a specified accuracy while dynamically updating the camera’s zoom, focus, and other parameter values based on the detected marker’s depth distances. For a 10 mm square micro AR marker, the proposed system demonstrated recognition accuracy better than

\pm 1.0 %

for depth distance and

{2.5}^{\circ}

for posture angle, with a maximum recognition range of 1.0 m. In addition, the iterative calculation time was 0.7 s for the initial detection of the marker. These experimental results indicate that the proposed method and system can be applied to the precise robotic handling of small objects at a low cost. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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13 pages, 3195 KiB

Open AccessArticle

Development of a High Sampling Rate Data Acquisition System Working in a High Pulse Count Rate Region for Radiation Diagnostics in Nuclear Fusion Plasma Research

by Kunihiro Ogawa, Siriyaporn Sangaroon, Long Yong Liao, Eiji Takada and Mitsutaka Isobe

Electronics 2023, 12(18), 3898; https://doi.org/10.3390/electronics12183898 - 15 Sep 2023

Viewed by 1082

Abstract

In this study, a high sampling rate data acquisition system with the ability to provide timestamp, pulse shape information, and waveform simultaneously under a sub megahertz pulse counting rate was developed for radiation diagnostics for magnetic confinement nuclear fusion plasma research. The testing [...] Read more.

In this study, a high sampling rate data acquisition system with the ability to provide timestamp, pulse shape information, and waveform simultaneously under a sub megahertz pulse counting rate was developed for radiation diagnostics for magnetic confinement nuclear fusion plasma research. The testing of the data acquisition system under the high pulse counting rate condition using real signals was performed in an accelerator-based deuterium-deuterium fusion neutron source (Fast Neutron Source) at the Japan Atomic Energy Agency. We found that the pulse counts acquired by the system linearly increased up to 6 × 10⁵ cps, and the count loss at 10⁶ cps was estimated to be ~10%. The data acquisition system was applied to deuterium-deuterium neutron profile diagnostics in the deuterium gas operation of a helical-type magnetic confinement plasma device, called the Large Helical Device, to observe the radial profile of neutron emissivity for the first time in a three-dimensional magnetic confinement fusion device. Time-resolved measurements of the deuterium-deuterium fusion emission profile were performed. The experimentally observed radial neutron emission profile was consistent with numerical predictions based on the orbit-following models using experimental data. The data acquisition system was shown to have the desired performance. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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12 pages, 4447 KiB

Open AccessArticle

Development of Directional 14 MeV-Fusion Neutron Detector Using Liquid-Scintillator-Filled Capillaries

by Masataka Teshigawara, Eiji Takada, Shuhei Sumida, Kouji Shinohara, Takeo Nishitani, Sangaroon Siriyaporn, Longyong Liao, Kunihiro Ogawa, Mitsutaka Isobe, Shigeo Matsuyama, Misako Miwa, Sho Toyama, Isao Murata, Shingo Tamaki and Sachie Kusaka

Electronics 2023, 12(15), 3219; https://doi.org/10.3390/electronics12153219 - 25 Jul 2023

Viewed by 1196

Abstract

Triton burnup studies have been performed in fusion experimental devices to evaluate the confinement performance of 3.5 MeV alpha particles. For this purpose, the generation rate of deuterium-tritium (D-T)-born 14 MeV neutrons has been measured using a scintillating fiber detector. The directionality of [...] Read more.

Triton burnup studies have been performed in fusion experimental devices to evaluate the confinement performance of 3.5 MeV alpha particles. For this purpose, the generation rate of deuterium-tritium (D-T)-born 14 MeV neutrons has been measured using a scintillating fiber detector. The directionality of this detector provides excellent selectivity for 14 MeV neutrons; however, the lack of a pulse–shape discrimination (PSD) capability limits high-energy gamma-ray reduction. In this study, we developed a new 14 MeV neutron detector with directionality that can discriminate neutrons and gamma rays based on the PSD technique by filling capillaries with a liquid scintillator. The performance of this detector was evaluated at the FNL (Tohoku University, Japan) and OKTAVIAN (Osaka University, Japan). The detector response was modeled using the particle and heavy ion transport code system (PHITS). The experimental and simulation results demonstrated that the detector has a directional response to fast neutrons and excellent PSD capability. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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11 pages, 551 KiB

Open AccessCommunication

Fractional Encoding of At-Most-K Constraints on SAT

by Miki Yonekura and Shunji Nishimura

Electronics 2023, 12(15), 3211; https://doi.org/10.3390/electronics12153211 - 25 Jul 2023

Viewed by 574

Abstract

The satisfiability problem (SAT) in propositional logic determines if there is an assignment of values that makes a given propositional formula true. Recently, fast SAT solvers have been developed, and SAT encoding research has gained attention. This enables various real-world problems to be [...] Read more.

The satisfiability problem (SAT) in propositional logic determines if there is an assignment of values that makes a given propositional formula true. Recently, fast SAT solvers have been developed, and SAT encoding research has gained attention. This enables various real-world problems to be transformed into SAT and solved, realizing a solution to the original problems. We propose a new encoding method, Fractional Encoding, which focuses on the At-Most-K constraints—a bottleneck of computational complexity—and reduces the scale of logical expressions by dividing target variables. Furthermore, we confirm that Fractional Encoding outperforms existing methods in terms of the number of generated clauses and required auxiliary variables. Hence, it enables the efficient solving of real-world problems like planning and hardware verification. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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12 pages, 5084 KiB

Open AccessArticle

Adjustment Method of MEMS Dual-Cantilever Deflection Using Plastic Deformation of Al and Ni Thin Film by Thermal Annealing

by Masaru Tanaka, Yota Iijima, Yusuke Masuda, Tsubasa Sato and Takashi Mineta

Electronics 2023, 12(14), 3153; https://doi.org/10.3390/electronics12143153 - 20 Jul 2023

Viewed by 977

Abstract

Deflection mismatch exists in microelectromechanical systems (MEMSs) cantilevers. To adjust for this mismatch, we devised a method to form Al and Ni films on the cantilever and adjusted the film stress by thermal annealing at a low temperature for a short duration. Thus, [...] Read more.

Deflection mismatch exists in microelectromechanical systems (MEMSs) cantilevers. To adjust for this mismatch, we devised a method to form Al and Ni films on the cantilever and adjusted the film stress by thermal annealing at a low temperature for a short duration. Thus, the film stress of the Al film was successfully adjusted by annealing at 150–400 °C for 1–5 min. During this process, the compressive thermal stress caused by the thermal expansion mismatch at 150 °C or higher led to plastic deformation, resulting in an enhanced tensile stress state after cooling. The Ni film stress changed from a compressive side to a tensile side after annealing at 200–400 °C for 1–30 min because of the film shrinkage caused by crystallization and crystalline orientation during the annealing process. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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16 pages, 12599 KiB

Open AccessArticle

Optimization of Shape-Variable Gamma Camera to High-Dose-Rate Regions

by Kengo Miyada, Eiji Takada and Yuki Sato

Electronics 2023, 12(12), 2640; https://doi.org/10.3390/electronics12122640 - 12 Jun 2023

Viewed by 845

Abstract

To proceed with the decommissioning of the Fukushima Daiichi Nuclear Power Station, it is necessary to visualize radioactive substances using a gamma camera in high-dose-rate regions inside a nuclear reactor building. We developed an umbrella-shaped Compton camera, whose sensitivity distribution can be adjusted [...] Read more.

To proceed with the decommissioning of the Fukushima Daiichi Nuclear Power Station, it is necessary to visualize radioactive substances using a gamma camera in high-dose-rate regions inside a nuclear reactor building. We developed an umbrella-shaped Compton camera, whose sensitivity distribution can be adjusted by changing its shape. When used on a robot, the moving distance of the robot can be reduced compared to a pinhole camera that is sensitive only to the front surface. In addition, unlike an omnidirectional Compton camera, the sensitivity in a specific direction can be increased, which is expected to expand the degree of freedom of measurement. In this study, the characteristics of the developed system were evaluated through simulations and experiments for application in a high-level radioactive environment inside a reactor building. It is estimated that this system can operate at a dose rate of approximately 2.68 mSv/h. Furthermore, we devised a method to compensate for the effect of the dead time of the SiPM (MPPC) in the high-dose-rate region by monitoring the current of the SiPM drive power supply and evaluating its applicability to high dose rates. This correction method was validated in the case where the photoelectric peak of the energy spectra fluctuated by approximately 60 keV due to dead time. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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18 pages, 15432 KiB

Open AccessEditor’s ChoiceArticle

An AR Application for the Efficient Construction of Water Pipes Buried Underground

by Koki Inoue, Shuichiro Ogake, Kazuma Kobayashi, Toyoaki Tomura, Satoshi Mitsui, Toshifumi Satake and Naoki Igo

Electronics 2023, 12(12), 2634; https://doi.org/10.3390/electronics12122634 - 12 Jun 2023

Viewed by 1089

Abstract

Unlike other civil engineering works, water pipe works require digging out before construction because the construction site is buried. The AR application is a system that displays buried objects in the ground in three dimensions when users hold a device such as a [...] Read more.

Unlike other civil engineering works, water pipe works require digging out before construction because the construction site is buried. The AR application is a system that displays buried objects in the ground in three dimensions when users hold a device such as a smartphone over the ground, using images from the smartphone. The system also registers new buried objects when they are updated. The target of this project is water pipes, which are the most familiar of all buried structures. The system has the following functions: “registration and display of new water pipe information” and “acquisition and display of current location coordinate information.” By applying the plane detection function to data acquired from a camera mounted on a smartphone, the system can easily register and display a water pipe model horizontally to the ground. The system does not require a reference marker because it uses GPS and the plane detection function. In the future, the system will support the visualization and registration of not only water pipes but also other underground infrastructures and will play an active role in the rapid restoration of infrastructure after a large-scale disaster through the realization of a buried-object 3D MAP platform. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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18 pages, 19386 KiB

Open AccessArticle

Development of a Robot for Decontamination of High Places and Decommissioning Work That Can Cope with Slopes and Steps

by Shuichiro Ogake, Yu Yoshimura, Koki Inoue, Shu Kobayashi, Kazuma Kobayashi, Satoshi Mitsui, Toshifumi Satake and Naoki Igo

Electronics 2023, 12(11), 2403; https://doi.org/10.3390/electronics12112403 - 25 May 2023

Viewed by 921

Abstract

In this study, a robot was created to compete in the “7th Decommissioning Creative Robot Contest. The “Decommissioning Creative Robot Contest” is a robot contest in which the fields and tasks are set based on the assumption of decommissioning work at TEPCO’s Fukushima [...] Read more.

In this study, a robot was created to compete in the “7th Decommissioning Creative Robot Contest. The “Decommissioning Creative Robot Contest” is a robot contest in which the fields and tasks are set based on the assumption of decommissioning work at TEPCO’s Fukushima Daiichi Nuclear Power Station. The theme of this year’s competition is 3D decontamination of a highly contaminated area inside a nuclear reactor building. To solve the competition problem, we propose a robot for decommissioning work equipped with “an undercarriage mechanism that can cope with slopes and steps”, “a decontamination mechanism with two types of rotation trajectories”, and “a lifting mechanism with a high deformation rate. The undercarriage mechanism uses a four-wheel drive with infinite orbit to cope with slopes and steps. The decontamination mechanism uses two different types of orbits for decontamination: a circular rotating orbit and a longitudinal rotating orbit for rotation. For the lifting mechanism, three pantograph mechanisms were used. This study realized a control and mechanism to overcome steps and slopes, a deployment mechanism to high places, and a mechanism with two types of orbits to carefully decontaminate a large area. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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11 pages, 4447 KiB

Open AccessCommunication

Can Deep Generative Models Explain Brain Function in People with Developmental Dyslexia?

by Hiroto Ogawa, Sakiko Ogoshi, Yasuhiro Ogoshi and Akio Nakai

Electronics 2023, 12(10), 2305; https://doi.org/10.3390/electronics12102305 - 19 May 2023

Viewed by 1004

Abstract

Many developmental disorders are diagnosed based on symptoms, which may result in lumping together multiple causes. This is thought to be a factor that complicates the research and treatment of developmental disorders. The purpose of this study is to provide hypotheses on the [...] Read more.

Many developmental disorders are diagnosed based on symptoms, which may result in lumping together multiple causes. This is thought to be a factor that complicates the research and treatment of developmental disorders. The purpose of this study is to provide hypotheses on the causes of brain functions in developmental dyslexia (DD) by constructing and analyzing a simple computational model of visual information processing using a deep generative model. We then analyze three symptoms observed in DD and investigate their functions and causes. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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15 pages, 3531 KiB

Open AccessArticle

Studies on the Control of Dermanyssus gallinae via High-Voltage Impulse

by Takahisa Ueno, Yuma Mizobe, Junko Ninomiya, Takahiro Inoue, Takashi Furukawa and Takeshi Hatta

Electronics 2023, 12(4), 1038; https://doi.org/10.3390/electronics12041038 - 19 Feb 2023

Cited by 1 | Viewed by 1665

Abstract

Dermanyssus gallinae, a parasitic mite that subsists on the avian blood of chickens, poses a considerable threat to the poultry industry. D. gallinae infestation can result in a plethora of detrimental effects for the host birds, including decreased egg production and anemia. [...] Read more.

Dermanyssus gallinae, a parasitic mite that subsists on the avian blood of chickens, poses a considerable threat to the poultry industry. D. gallinae infestation can result in a plethora of detrimental effects for the host birds, including decreased egg production and anemia. Pyrethroid pesticides have been the primary means of combating this issue and have demonstrated high levels of efficacy. However, in recent years, D. gallinae has exhibited resistance to these chemicals, resulting in a marked decrease in their mortality; thus, an integrated control strategy in addition to the chemical use should be required for the sustainable control of this mite. This study confirms that D. gallinae can be effectively controlled through the utilization of high-voltage impulse discharges and that various electrical parameters possess optimal values that are required for mite control. The alterations in the body surface of the mite caused by high-voltage impulses were akin to those caused by heat, but no alteration in the elemental composition of the body surface was observed, suggesting a change in organization caused by currents flowing inside the exoskeleton. Comparatively, the mite control efficacy of high-voltage impulse was found to be substantially superior to that of ultraviolet light or ozone, with up to 95% more mites being killed in as little as 30 seconds. Full article

(This article belongs to the Special Issue Science and Technology of Advanced Electronics, Sensing Systems and AI Applied to Society: Including Collections from the Latest Papers of KRIS 2023)

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