Magnetic bearings include superconductive, active, and passive types. There are two types of passive magnetic bearings: repulsion force type and attractive force type. The repulsion force type requires permanent magnets in both the rotor and stator, whereas the attractive force type requires only one permanent magnet, which simplifies the structure. The stiffness of the attractive force type passive magnetic bearings changes with the end shape of the rotor shaft. However, it is not clear how the stiffness changes with the change in geometry, and the evaluation method of the stiffness has not been established. In this paper, finite element analysis is used to determine the tilt torque acting on the rotating shaft, the center of rotation, the radial force and its point of action, and to evaluate the stiffness. The effects of changing the geometry of the shaft end are discussed.

　This research expresses a novel active vibration control method for structures by using magnetic levitation (MAGLEV) technologies. When a vibration occurs, an iterative MAGLEV device is developed to levitate and contact the celling of structures properly. The device is in contact when the product of ceiling displacement and velocity is positive, and non-contact when it is negative. To make the device float stably, a sliding mode control method is used. A vibration control target simulating a two-story house is subjected to standing wave excitation and random excitation. The standing wave excitation adds vibrations near the first- and second-order natural frequencies. Similarly, random excitation adds a random excitation that emphasizes each of the first- and second-order eigenfrequencies. The amplitudes of the displacements of each ceiling are derived by Fourier transform and compared. The experimental result shows the effect of this device on the vibration control of the structure.

　Magnetic bearings (MBs) can support a rotating shaft without contact using electromagnetic force. A common 5-DOF magnetic levitation system uses two radial MBs and one axial MB. However, this system tends to become large due to the combination of three MBs, and it poses an issue of reduced critical speed as the shaft length increases. Therefore, 3-DOF MBs with an integrated structure combining radial and axial MBs have been proposed to address these challenges. In this study, we propose reluctance-type 3-DOF MBs capable of providing support in 3-DOF with a high support force density. In this paper, we present a structure that can increase the opposing surface where the magnetic attractive force acts to achieve high support force density. Additionally, to further improve the support force density, we propose a new excitation method based on the characteristic of magnetic flux interference in 3-DOF MBs.

　In recent years, demand for thin steel plate used in automobiles and home appliances has been increasing. In the steel plate manufacturing process, deterioration of surface quality due to contact between rollers and steel plate has become a problem. As a solution to this problem, research has been conducted on non-contact conveyance using magnetic levitation technology. However, when flexible thin steel plates are used for levitation, it is difficult to control levitation due to large deflection. Therefore, our research group has proposed a Bending magnetic levitation system using bending flexible steel plates and has confirmed that levitation is stable. However, the behavior of the steel plate during levitation has not yet been fully clarified. In this study, the vibration characteristics of flexible steel plates were investigated from the dynamic behavior of the steel plates by applying a disturbance to the plates during bending magnetic levitation.

　In thin steel plate production lines, the problem of surface quality deterioration of steel sheets in contact conveying by rollers has become an issue. As a solution to this problem, we have proposed an energy-saving magnetic levitation system that uses electromagnets for magnetic levitation and permanent magnets for levitation assistance. In this study, an experimental investigation was conducted on the effect of the tension application position on the vibration characteristics of thin steel plates when they are magnetically levitated.

　Thin steel sheets widely used in automobiles and other industrial products are manufactured by contact conveying using rollers. However, contact with the rollers causes scratches and unevenness, resulting in deterioration of surface quality. Therefore, a non-contact magnetic levitation transfer of thin steel sheets using the attractive force of electromagnets has been proposed. In this study, a basic investigation was conducted to determine the effect of the electromagnet installation position on the transfer performance when thin steel plates are magnetically levitated by applying a magnetic field from the edge direction.

　Thin steel plates are widely used in automobiles, household appliances, and other products, and there is a demand for improved surface quality. However, since contact conveyance using rollers is used in the conveyance process in thin steel sheet production lines, deterioration of surface quality is a problem. Therefore, a method of non-contact gripping and conveying of thin steel plates by magnetic levitation has been proposed. However, when thin steel plates are levitated by the attractive force of electromagnets, the plates deflect, making stable levitation difficult. Therefore, the authors proposed an edge-supported magnetic levitation system in which electromagnets are placed only at the edges of thin steel plates to achieve stable levitation. In this report, the levitation characteristics were examined by changing the arrangement of electromagnets.

　Flexible steel plates are widely used in various industrial fields. Flexible steel plates are currently conveyed by rollers in the conveying process, and the contact between the steel plate and the rollers can cause minute scratches on the surface of the steel plate. These scratches can cause quality deterioration of the steel plate surface. To solve this problem, research has been conducted on non-contact gripping of flexible steel plates using a magnetic field from an electromagnet. Steel plates are thin and easily deflected, and they tend to vibrate in complex shapes during magnetic levitation. Therefore, the authors have proposed a magnetic levitation system in which two electromagnets are placed on each of the two sides of a flexible steel plate to be levitated. In this report, the effects of plate thickness and steady-state current on levitation stability are clarified.

　This paper proposes the optimization of magnet shape combination and cogging torque cancellation method for a double rotor-single stator axial gap motor. Since the two axially opposite surfaces are torque-generating surfaces, the motor is expected to generate a high torque density in a flat structure. Cogging torque is a major issue because it determines the quality of the motor. Previously, the authors proposed the magnet in the shape of multiplicative wave and confirmed that it is useful for reducing cogging torque. In this study, the combination of the multiplied-wave magnet shapes in the top and bottom rotors was optimized to cancel out the harmonic components of the cogging torque generated between each gap. As a result, the cogging torque was significantly reduced while maintaining the same torque.

　Currently, permanent magnet synchronous motors (PMSMs) are commonly used for EV traction motors. However, there are some problems in the cost of permanent magnets, high speed rotation, and the stable supply of rare earth resources. On the other hand, switched reluctance motors (SRMs) have simple, robust and inexpensive structure. However, SRMs have problems such as a large torque ripple, noise and vibration. In addition, SRMs are driven by a 3-phase asymmetric inverter, and the inverter cost is higher than a 3-phase inverter. Therefore, in order to solve these problems, we have proposed a 12/10 SRM that uses a hex connection and is driven by a 9-switch inverter. In this paper, a 12/10 SRM with hex connection is designed, and the characteristic under pulse drive using conventional 6-phase inverter and 9-switch inverter are compared. Finally, the difference between the 6-phase inverter and 9-switch inverter is discussed.

　With the spread of motors, magnetically geared motors are attracting attention. In this paper, the electromagnetic force that causes vibration in magnetically geared motor is examined. The characteristics of the electromagnetic force in a magnetically geared motor is investigated using a three-dimensional finite element method analysis. From the analysis results. It was confirmed that the fundamental excitation mode of the electromagnetic force reaches its maximum at five times the fundamental frequency. To verify the validity of the analytical results, measurements on a prototype were carried out. It was confirmed that the analysis result showed a good agreement with the measured values.

　The authors have been studying non-contact brakes using eddy current brake as the next generation for aircraft. This paper deals with basic characteristics of double rotor type eddy current brakes by measurement of experimental machine and analysis. As a result, the measured braking torque value of the experimental machine was smaller than the value derived from analysis. And the analytical values do not take thermal characteristics into account, so there is a difference with the measured values from an experimental machine that generates heat. By considering the effect of energy stored in the coil, it was found that the energy stored in coil smaller than the heat generation one.

　We propose a 6-phase 12/10 switched reluctance motor (SRM) with a hex connection. The transformation between star and hex connections is not equivalent as that between star and delta connections of conventional 3-phase motor. In this paper, the transformation between star and hex connections is theoretically described. In addition, the current condition that maximizes torque is described. Finally, the torque of both connections is compared in terms of the AC-DC current ratio.

　This paper describes a bearingless motor with both passive and active axial stabilization. Passive stabilization through Null flux coils in the shape of Figure-8 has earlier been proposed in various papers. As the electrodynamic force in the symmetrical configuration increases with the rotational speed, levitation can be achieved only after a threshold speed. The active control of axial force was not possible with the symmetrical rotor configuration. This paper proposes a modification to the stator coil circuit by connecting an external inductance to any one of the coils to achieve active control of axial force with an external supply. The axial force sufficient enough to compensate for rotor weight and any unstable axial forces can be achieved at low rotational speeds. Theoretical equations for axial forces have been derived and the results have been compared with FEA. The rotational speeds at which the levitation occurs have been estimated theoretically and experimentally.

　Vernier motors are attracting attention as direct drive motors without mechanical gears, in order to applied to higher torque. The authors have developed an inner-rotor type vernier motor, applying cores made of the oriented electrical steel sheets to increase efficiency. In this paper, to improve torque characteristics and gear ratios, outer-rotor type structures, which can be easily multi-polarized, are employed. The motor topologies and torque characteristics are investigated by using the finite element method. As a result, it was found that, unlike the conventional inner-rotor types, the outer-rotor types showed higher average torque, by using the distributed windings and stator modular constructions. As for the model applied the eleventh harmonic revealed 2.5 times higher torque in comparison with the basic model with the fifth harmonic.

　The linear system which appears in the shielding current analysis of the HTS film without a crack has the symmetric and dense coefficient matrix. In this study, the H-matrix-based preconditioning has been proposed for accelerating the conjugate gradient (CG) method which is adopted as a solver of the linear system and its performance has been investigated. The result of computations shows that the H-matrix-based preconditioned CG method is much faster than the standard one.

　When a monopole antenna is placed at one of the two focal points of an elliptical chamber and microwaves are radiated into the chamber, the object to be heated at the other focal position can be heated with high efficiency. Depending on the shape of the object to be heated, the field inside the chamber may be disturbed and reflected waves may be generated. Therefore, we installed a regulator called a stub tuner that can match the impedance in the chamber. This cancels the reflected waves in the chamber. Simulations show that 99.97% of the microwaves are absorbed by the object being heated.

　This paper describes the sterilization ability of dielectric heating by counting the number of viable bacteria on salmon before and after heating, with the aim of commercializing a low-temperature cooker using dielectric heating. In dielectric heating, the food is sandwiched between two copper plate electrodes and an alternating current with a frequency of 600 to 800 kHz was applied. Salmon were heated by dielectric heating, killing 97.8-99.7% of the bacteria on their surfaces. In addition, a comparison of low-temperature cookers using dielectric heating and low-temperature cooking using a hot water bath, which is currently widely used, revealed that they have the same level of sterilizing ability. When current was applied without heating the food, bacteria multiplied by more than 1.7 times, indicating that current has no sterilizing ability at frequencies between 600 and 800 kHz.

　This paper describes a non-invasive method for classifying the motions of each finger using tactile features for the purpose of controlling a motorized prosthetic hand for the forearm. Tactile sensors were developed using polyvinylidene difluoride (PVDF) to detect tactile features on forearm surface caused by motion of fingers. The two tactile sensors were placed on the extensor digitorum and flexor digitorum superificialis on the forearm, and feature values were extracted from the measured signals. Using the obtained features as input, the motions were classified using machine learning. In this paper, comparisons were made using five different classifiers. Experimental results showed that the linear support vector machine obtained an average classification rate of more than 86% by using only two PVDF tactile sensors. It was also found that thirteen trials were required per type of motion.

　This paper reports on a performance study of an electric prosthetic hand using a new electric prosthetic hand control method, the tactile feature sensing system. This prosthetic hand is controlled by attaching tactile sensors made of polyvinylidene fluoride (PVDF) to the forearm skin surface to detect changes in tactile properties such as forearm muscle protuberance, contraction, and stiffening. This paper investigates the influence of fatigue, perspiration, and other conditions that may occur after prolonged use of a prosthetic hand, on the accuracy of hand motion classification. The results showed that perspiration did not deteriorate the accuracy of hand motion classification but serve fatigue conditions reduced accuracy. Therefore, to solve this problem, we attempted to improve accuracy by changing or adding feature values to be evaluated.

　In this paper, we developed a hybrid magnetorheological transmission for flow balance control of total artificial hearts. The transmission consists of input and output shafts, magnetorheological fluid, permanent magnets, and an electromagnet with adjustable current. A motor rotates the input shaft of the transmission. The transmission transfers the torque to the output shaft that rotates with decelerated rotational speed according to the apparent viscosity of the magnetorheological fluid. First, we analyzed that magnetic flux density distribution according to the current by 3D finite element method. Analyzed results showed that magnetic flux density was regulated by field weakening. Second, we measured the output rotational speed when load torque was 5 mNm and the input rotational speed was 2000 rpm. The difference between input and output rotational speed changed from 4 rpm to 235 rpm since we applied current at 0.5 A. From analyzed and experimental results, it was clarified that the developed transmission had small size, low power consumption and sufficient transmission performance.

　A maglev blood pump using an axial flux self-bearing motor has been developed. Sensorless angle and speed control technique is desired to improve mechanical durability and reduce number of wires of drive lines for practical use of the maglev blood pump. In this study, sensorless angle estimation by using back EMF generated in stator winding during impeller rotation was applied to the 5-degrees of freedom (5-DOF) controlled self-bearing motor. This paper proposed a real-time winding inductance estimation to improve the rotating angle estimation accuracy. Non-contact impeller suspension of the maglev blood pump driven with sensorless control was demonstrated. The angle estimation accuracy was deteriorated without radial position control because a symmetrical three-phase back EMF waveform could not be obtained due to whirling of the levitated impeller. In contrast, highly accurate angle estimation was achieved with an error of less than 5 degrees in all pumps driving condition by suppressing the impeller whirling with 5-DOF position control.

　Wireless power transmission systems have been considered for implantable locomotion meters from the viewpoints of limitation of measurement time and stress on animals due to their weight. On the other hand, studies on the power receiving circuit for this system have not been conducted. In addition, although the system is intended to measure the activity of several small laboratory animals, the effects of multiple power receiving coils approaching each other have not been clarified. Therefore, we fabricated prototype transmitter and receiver for wireless power transmission and investigated the changes in coupling coefficient and voltage when several receivers are in close proximity to each other. As a result, we showed that even when multiple small laboratory animals with implanted power receiving circuits were close to each other in the system, it was possible to supply a power receiving voltage higher than the target voltage of locomotion meters.

　Electromagnetic waves are widely used for various purposes in the modern age. However, the effects of electromagnetic waves on the human body are still largely unknown. In particular, there is a lack of basic research data in the intermediate frequency range of 300 Hz to 10 MHz compared to other frequency bands, and further research is needed. Previous studies have suggested that magnetic fields with a frequency of 400 kHz and a magnetic field strength of 10 A/m affect locomotor activity and brain matter in living organisms. In this study, we investigated the effects of a magnetic field of 25 A/m, which is stronger than the previous study, on locomotor activity and brain matter. As a result, we report our findings suggesting that magnetic fields reduce the amount of locomotion in the organism by about 30% and change the amount of monoamine neurotransmitters secreted in the brain.

　We have developed an advanced post-processing technique designed to enhance the resolution of electrical impedance tomography (EIT). The technique used logical correlations between images reconstructed by several solving methods of inverse problem. We obtained various potential spectra using both adjacent and opposite measurement modes and visualized them using both regularization and machine learning methods. For object size, machine learning was the most effective. For object position, logical AND processing using Gauss-Newton method from both adjacent and opposite modes was effective.

　Although laparoscopic surgery is less invasive than laparotomy, it leaves four or five surgical wounds in the abdomen, and patients for whom postoperative cosmetics are important are reluctant to undergo surgery. Laparo-endoscopic single site surgery has the advantage of using the umbilical hole to perform the surgery, leaving only one surgical wound and providing excellent postoperative cosmetics. On the other hand, it has the disadvantage of high operative difficulty due to the concentration of instruments in a single location. Therefore, in this study, I will develop a new bending forceps that solves the disadvantages of laparo-endoscopic single site surgery and achieves a surgical sensation equivalent to that of conventional laparoscopic surgery. In this paper, the characteristics and mechanism of the forceps to be developed are described, and the performance of the fabricated leaf springs and torque coils are quantitatively evaluated.

　In Japan, breast cancer ranks fifth in cancer-related deaths among women, constituting about 10% of all cancer fatalities. Existing treatments, like surgery or chemotherapy, have significant side effects. Especially, Triple Negative Breast Cancer (TNBC) demonstrates a high recurrence rate within three years and a shorter post-relapse survival. Given these challenges and the expected rise in breast cancer incidences, this study focuses on TNBC, exploring the potential of Atmospheric Low Temperature Plasma (ALTP) as a treatment. Recently recognized for its safety and adaptability in medical applications, this research delves into ALTP's effects on cultured breast cancer cells, emphasizing both cell proliferation and the gene expression of inflammatory cytokines, caspase 3 and 9.

　The skin plays a protective role against various environmental stimuli. Promoting healing is extremely important because failure to heal leads to a decline in QOL. Current treatments for skin wounds have side effects such as skin atrophy and drug allergies, so there is a need for less invasive treatments. In recent years, medical applications of atmospheric low temperature plasma (ALTP) have been promoted. Skin wound treatment is one of these uses. In this study, we investigated the effects of ALTP on skin injuries by shortening the healing time of ALTP treatment and analyzing gene expression using RT-qPCR. ALTP irradiation was shown to increase the expression levels of IL-6 and HIF-1α during the inflammatory phase. These results suggest that ALTP promotes healing in wound tissue during the inflammatory phase via inflammatory cytokines and hypoxia-inducible factors.

　Pulmonary arterial hypertension (PAH) is a severe respiratory disease caused mainly by stenosis of small pulmonary arteries. For cure the disease, we focused on active nitrogen species (RNS), which are produced during atmospheric low temperature plasma (ALTP) generation and have vasorelaxant effects, in order to investigate the suppression of PAH symptoms. This study aims to investigate the suppression of PAH symptoms by focusing on reactive nitrogen species (RNS), which occur during PAH and have vasorelaxant effects.

　In this study, we focused on PAH caused by stenosis of small pulmonary arteries and aimed to suppress symptoms using ALTP. In this study, we evaluated the suppression of PAH by in vivo administration of ALTP-irradiated saline solution (PTS: plasma treated saline) to a rat model of PAH using electrocardiographic P-waves. Therefore, it was suggested that PTS administered with ALTP treatment suppressed the symptoms of PAH.

　In magnetic particle testing (MT), it is necessary to magnetize in the appropriate direction with sufficient strength. However, for test subject with complex shape, achieving adequate magnetization in the desired direction can be challenging. As a result, the inspected object is not properly magnetized, and cracks may be overlooked. Therefore, we considered the enhancement of reliability in MT for complex shaped test object using a three-dimensional rotating magnetic field. In this study, an MT magnetization system for applying a three-dimensional (3D) rotating magnetic field to large structures was examined. Two magnetizers were arranged at an angle of 90°, and magnetization distributions on the surface of the test object placed at the intersection of two magnetizers were evaluated using finite element analysis. The achievement of omnidirectional magnetization was confirmed in each part of the complex shape with changing the applied magnetic field angle to the test object.

　The propagation velocity of elastic waves in a ferromagnetic material varies not only with stress but also with magnetization, which is called the magnetoacoustic effect. This effect is the basic principle of magnetoacoustoelastic method. Although magnetoacoustoelastic method can theoretically evaluate stress more precisely than conventional acoustoelastic methods, there has been no application of magnetoacoustoelastic methods to biaxial stress evaluation of plates. In this study, we developed a magnetoacoustic effect measurement system that can transmit and receive surface SH waves while applying biaxial compressive stress with an arbitrary directional magnetic field to a plate. Then, we measured basic data on a nickel with a pronounced magnetoacoustic effect and discussed the usefulness of magnetoacoustoelastic method for biaxial stress evaluation of plates.

　In this paper, a measurement method of the magnetic properties in the teeth part of motor cores is investigated, and the magnetic properties before and after the stress-relief annealing are compared. At first, the effective magnetic path length for measuring the magnetic field strength was determined using a two-dimensional magnetic filed analysis, and its validity was demonstrated. Next, it was confirmed that the developed magnetic sensor can evaluate the effect of rolling magnetic anisotropy by measuring the magnetic properties in the different teeth of the motor core. Finally, the stress-relief annealing using an induction current was carried out, and it was clear that the magnetic properties of each teeth of the motor differ at the upper and middle parts.

　Due to energy issues in recent years, there has been a demand for energy-saving electrical machines, and transformers have been subject to the Top Runner System since 2006. Iron loss, which is one type of transformer loss, is caused by the iron core material, and it is known that the iron loss increases due to rotating magnetic flux that occurs especially around T-junctions. The authors have developed vector magnetic characteristic control technology that can reduce iron loss under rotating magnetic flux in existing grain-oriented electrical steel sheets, and have clarified guidelines for applying this technology to electrical equipment cores. This paper clarifies the application area of control technology for rotating iron loss occurring in a three-phase transformer model core based on vector magnetic characteristic analysis and the above-mentioned guidelines, and also applies it to an actual three-phase transformer model core and conducts actual measurements. We will investigate and report on the iron loss reduction effect.

　The development of highly efficient, high-output motors and transformers is promoted upon the improvement in the magnetic properties of magnetic materials. Moreover, in these devices, the use of thin electrical steel sheets and wire rods has been widely encouraged. However, strategies for the measurement of the magnetic properties of wire materials have not been successfully explored. To bridge this gap, in this study, we propose a coaxial H-coil method. In this paper, we fabricate two coaxial H coils with different structures and report a comparative evaluation of the coaxial H coil method and the standard measurement method, the excitation current method, on electromagnetic steel sheets.

　The application of composite materials using magnetic wires to the iron cores of electrical equipment has been attracting attention. The conventional form of magnetic material has been to laminate plates such as electromagnetic steel sheets, but magnetic wire, which is a rod-shaped magnetic material, offers greater flexibility in processing, and thus can be expected to be more compact and lightweight, and may be applied to new structures. However, a method for measuring the magnetic properties of magnetic wires has not yet been established and standardized. Therefore, the authors have developed a simple magnetic property measurement device to evaluate the magnetic properties of magnetic wires. In this paper, we report the results of a basic study for the development of a simple magnetic property measurement device for magnetic wires by applying exciting a current method.

　Electrical steel sheets used in magnetic cores of electrical machines are generally coated with an electrical insulating coating to prevent oxidation and eddy current flow between layers. For this reason, when electrical steel sheets are annealed at 850°C or more, the insulation coating is destroyed, and the coating should be reprocessed. Therefore, we investigated how increase in eddy currents due to short circuits between laminations on eddy current loss in the case of laminated electrical steel sheets without insulation coatings. Comparing eddy current losses of ring samples without coating before and after lamination, the contact resistances was relatively large and the effect of conduction between the layers was not observed. In this paper, by measuring the magnetic properties of laminated ring samples with polished surface, which have different surface roughness, we report on the results in the study of the relationship between the surface roughness and eddy current loss.

　We have developed inchworm-type miniature robots using piezoelectric elements and electromagnets. The miniature robots are operated by synchronizing the micro-deformation of piezoelectric elements and the adsorption of electromagnets. The miniature robots are capable of both precise and wide-range motion. In this paper, we experimentally describe the control waveforms of the piezoelectric elements and electromagnets. It is clarified the followings. (i) Reduction of backward motion caused as a result of electromagnets by providing overlap time of more than 1/12 cycle to the electromagnets. (ii) By extending the piezo with a rise time of less than 0.2 ms and contracting it with a fall time of 0.6 ms - 6 ms, the backward motion of the miniature robot is reduced, and the displacement in one control cycle is improved. In addition, the displacement in one control cycle is improved by 1.23 times compared to the conventional control method.

　In this study, we investigated the introduction of phased shift array transmitters for expanding the positioning range of ultrasonic positioning systems. The result of numerical simulation shows the number of transmitters to three or more, sufficient sound pressure intensity can be obtained for distance measurement. In addition, we constructed a phased shift array using three transmitters. In the distance measurement experiment, it shows to change the phase direction, similar to the results of the numerical simulation.

　A new cooking method using sunlight as a heat source was proposed. We developed an inexpensive, lightweight, and non-bulky parabolic solar cooker and a special cooking container in the form of a donut-shaped aluminum pouch that can cook any food item in a short time and can be easily disposed of after use. Furthermore, the solar heat utilization rate of this device was calculated by simulation. The results showed that the solar utilization efficiency was about 9%, and that the cooking environment was limited by the illuminance, outside temperature, wind speed.

　Demand for aircraft is increasing, and there is concern that CO2 emissions from aircraft will increase. Accordingly, research on aircraft electrification is being conducted worldwide to reduce emissions. The authors have proposed a non-contact hybrid brake system for aircraft using an electronically controllable eddy current brake and magnetorheological fluid brake. In previous studies, the basic characteristics and design of magnetorheological fluid brakes have been studied, but their feasibility for actual installation in aircraft has not been examined. Therefore, a model of the brake and the aircraft has developed based on the characteristics of the magnetorheological fluid brake. The results of calculations using this model are shown that magnetorheological fluid brakes can be used in aircraft.