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This study presents a novel two-step optimization method that incorporates explainable neural networks into topology optimization. The deep neural network (DNN) is trained to infer the torque performance from the input image of the motor cross section. The sensitive region that has a significant influence on the average torque is extracted using gradient-weighted class activation mapping (Grad-CAM) constructed from the DNN. Then, the optimization with respect to the torque ripple is performed only in the incentive region with little influence on the average torque. The proposed method is shown to increase the average torque of an interior permanent magnet (IPM) motor by 14% and reduce the torque ripple by 79% compared with the original model. [ABSTRACT FROM AUTHOR]

This paper presents a new pole‐changing method with multiple three‐phase inverters. Since the number of controllable current phases is much larger than that in conventional methods, a higher winding factor can be obtained in both high‐ and low‐pole driving modes. To evaluate the magnetic characteristics of the proposed method, magnetomotive force analysis is conducted based on Fourier series expansion and finite element method (FEM). Moreover, mutual inductance is compared between high‐ and low‐pole drives using FEM. To validate the effectiveness, an efficiency map is evaluated by using a prototype induction motor. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

The functional visual acuity test which is the average of the visual acuities measured during a specific time frame (standard, 60 seconds) has been used recently to assess the visual function in various conditions. The availability of a shorter version of the functional visual acuity test promises to be patient friendly in that it is a simple screening test performed in a shorter period of time than the standard test. The results of measurements of the FVA test between the 30-second measurement time (short-version FVA test) and the standard 60-second measurement are compared, and the feasibility of the short-version FVA test instead of the standard FVA test is investigated. Twenty-eight healthy volunteers (25 men and 3 women) were enrolled in this prospective observational study. All subjects underwent measurement of the binocular distance-corrected visual acuity and the binocular distance-corrected FVA with the 60-second and 30-second measurement times. The interchangeability of the corrected-distance FVA, maximal VA, visual maintenance ratio, and average response time in the short-version and the standard FVA tests was evaluated using the Bland–Altman method, and the results showed agreements of the two tests except for the minimal VA. The short-version FVA test is equivalent to the standard method except for evaluating the visual acuity fluctuations and promises to be a simple visual screening test that can be performed in a shorter time. [ABSTRACT FROM AUTHOR]

The magnetic characteristic of magnetic steel sheets used for rotating machines can be degraded by punching, cutting, or other manufacturing process. This degradation damages the performances of motors. This paper presents topology optimization of rotating machines considering the localized magnetic degradation caused by punching process. It is shown that the optimized synchronous reluctance motors obtained by this method satisfy the torque constraint under the existence of the magnetic degradation. [ABSTRACT FROM AUTHOR]

Purpose: To study the changes in corneal aberrations after cataract surgery. Methods: This study comprised 36 eyes of 36 patients (mean age, 67.3 years) who underwent cataract surgery through a 2.2-mm superior sclerocorneal incision. The anterior, posterior, and total corneal wavefront aberrations for the 6.0-mm pupillary diameter were measured preoperatively and 1 month postoperatively. The postoperative changes in corneal aberrations were evaluated for individual Zernike terms (Z, Z, Z, Z, Z, and Z) and the root mean squares of the third, fourth, and total higher-order aberrations (S3, S4, and THOA). Results: No significant postoperative changes were observed in S3 and S4 of the total and anterior cornea, although significant changes were observed in S4 and THOA of the posterior cornea. Regarding the preoperative and postoperative Zernike terms of the total cornea, the oblique astigmatism (Z) changed significantly ( P = 0.02). Significant positive correlations were observed in the Z, Z, Z Z, Z and Z between the changes in the total and the anterior cornea ( P < 0.001 for all comparisons). However, no correlations were observed in the changes in the Zernike terms between the total and the posterior cornea, except for the Z. Conclusions: The oblique astigmatism (Z) of the total cornea significantly changed after 2.2-mm-incision cataract surgery. The changes in the lower- and higher-order aberrations of the anterior cornea mainly contributed to the changes in the total cornea. [ABSTRACT FROM AUTHOR]

This paper presents robust topology optimization of electromagnetic machines by considering the magnetic degradation caused by mechanical and thermal stresses in punching, shrinking fitting, and other manufacturing processes. The topology optimization is performed using two methods: one is the robust genetic algorithm in which random noises are added to the magnetic characteristic parameters and the other takes the deviations in the objective and constraint functions due to the degradation into account. These methods are applied to optimization of the flux barrier shapes in an interior permanent magnetic motor to find that one can successfully realize robust design. [ABSTRACT FROM PUBLISHER]

This paper proposes a two-step method for topology optimization, in which after global search is performed by the on–off method, and then local search is carried out by the level set approach. The genetic and gradient-based algorithms are employed for the former and latter optimizations, respectively. This present method is applied to two numerical examples; topology optimizations of a magnetic shield system and interior permanent magnetic motor. It is shown that this present method can find solutions with better performances in comparison with the conventional on–off method. [ABSTRACT FROM AUTHOR]

The precursor dynamics of ferroelectric phase transitions in relaxor-based ferroelectric (1 - x) Pb(Zn1/3Nb2/3)O3-xPbTiO3 single crystals, with x = 0.07, 0.10, and 0.12, were investigated using inelastic light scattering from a longitudinal acoustic phonon. An acoustic anomaly in a broad temperature range, which is characteristic of relaxor ferroelectrics, was observed. We describe the anomalies in the paraelectric phase by assuming local piezoelectric coupling inside polar nanoregions, which are surrounded by a nonpolar matrix. On the basis of local piezoelectric coupling, a relaxation time τ and a dynamic characteristic length L of the order-parameter (polarization) fluctuations were determined to be in the order of 10-13s and 10-9 m, respectively. The τ and L values increase sharply upon cooling from high temperatures but more gradually below the intermediate temperature T* (=493 - 510 K). This result implies that the local polarization fluctuations grow rapidly upon cooling down to above T* and the growth rate decreases below T*. The inflexion point of this growth process in the paraelectric phase is related to the characteristic properties of relaxor-based solid solutions. [ABSTRACT FROM AUTHOR]

Aging of Na0.5 + xBi0.5 - xTiO3 - x (x = 0, 0.02) ceramics is studied by dielectric measurements. The time dependence of the dielectric property is well fitted by the stretched exponential function. The observed aging temperature dependences are different between Na0.52Bi0.48TiO2.98 and Na0.5Bi0.5TiO3 in relation with the concentration of oxygen vacancies. The aging temperature dependences of the relaxation intensity and the relaxation time in Na0.52Bi0.48TiO2.98 (which contains more oxygen vacancies) is consistent with the result of Monte-Carlo simulation which is based on the relaxation of defect dipoles in relaxor ferroelectrics. It is found that the oxygen vacancies are mainly responsible for the defect dipole. The aging behavior can be explained on the basis of the size of defect-dipole and its distribution. [ABSTRACT FROM AUTHOR]

• Subjects were exposed to non-flickering and 100-Hz flickering light at night. • Melatonin concentration was obtained via saliva samples during light exposure. • Both of the light conditions acute suppressed melatonin secretion. • The suppression of the flickering light was higher than non-flickering light. Bright light at night has been known to suppress melatonin secretion. Photoreceptors, known as intrinsically photosensitive retinal ganglion cells (ipRGCs), project dark/bright information into the superchiasmatic nucleus, which regulates the circadian system. Electroretinograms of ipRGCs show fluctuation that is synchronized with light ON-OFF stimulation. This finding suggests that the flickering condition of light may have an impact on our circadian system. In this study, we evaluate light-induced melatonin suppression under flickering and non-flickering light conditions. Fifteen male subjects between the ages of 20 and 23 years (mean ± SD, 21.9 ± 1.9) were exposed to three light conditions (dim, 100-Hz flickering and non-flickering light) from 1:00 a.m. to 2:30 a.m. Saliva samples were taken just before 1:00 and at 1:15, 1:30, 2:00, and 2:30 a.m. Repeated-measure t -test with Bonferroni correction showed a significant decrease in melatonin levels under both 100-Hz and non-flickering light conditions compared to dim light conditions after 2:00 a.m. Moreover, at 2:30 a.m., the rate of change in melatonin level under 100 Hz of flickering light was significantly lower than that under non-flickering light. Our present findings suggest that 100-Hz flickering light may suppress melatonin secretion more than non-flickering light. [ABSTRACT FROM AUTHOR]

This article proposes a two-step topology optimization method based on the normalized Gaussian functions. The proposed method is shown to be effective for design of a claw-pole alternator. In this method, the global search using the micro-genetic algorithm ($\boldsymbol {\mu }$ GA) is followed by the local search using the sensitivity analysis based on the adjoint variable method. The 3-D structure of the rotor is optimized using the proposed method under low- and high-speed conditions. [ABSTRACT FROM AUTHOR]

In this study, we propose a fast topology optimization (TO) method based on a deep neural network (DNN) that predicts the current-dependent motor torque characteristics using its cross-sectional image. The trained DNN is shown to provide the current condition that provides the maximum torque under the assumed motor control method. The proposed method helps perform TO with a reduced number of field computations while maintaining a high search capability. [ABSTRACT FROM AUTHOR]

In this article, we propose an interactive visualization method for motor design. We have proposed a visualization system for education using augmented reality (AR) and virtual reality (VR). As a further development of this, we are working on motor design as an industrial application. There are two issues in achieving high-speed interactivity. One is a fast mesh modification method in finite element analysis, and the other is a fast solving method. We propose a high-speed mesh modification method that utilizes regularly arranged grid points and coordinate transformation. In the proposed design system, the user can immediately observe the analysis result of the design change. Furthermore, if the proposed system is executed in cooperation with the projector, designers can change the design of the motor with their fingers and discuss it on the board. Furthermore, since this system can be executed on a Web browser, it can also be executed on a smartphone or tablet PC. [ABSTRACT FROM AUTHOR]

The phase transition temperatures and piezoelectric properties of (Bi0.5Na0.5)TiO3 (BNT) ceramics and single crystal were investigated. This study revealed that the high conductivity of BNT ceramics is attributed to the Bi vaporization during sinterint. The highest depolarization temperature Td of 187°C was obtained for the stoichiometric BNT ceramics, and Td tends to decrease as the composition deviates from stoichiometric BNT. Td of BNT single crystal was 158°C because of Na poor composition. BNT ceramics was easy to pole fully when the Bi/Na ratio is more than 1.0. The electromechanical coupling factor k33 and piezoelectric properties d33 of fully poled stoichiometric BNT ceramics were 0.459 and 72.9 pC/N, respectively. [ABSTRACT FROM AUTHOR]

Glycemic control is essential to manage metabolic diseases such as diabetes. Frequent measurements of systemic glucose levels with prompt managements can prevent organ damages. The eye is a glucose highly demanding organ in our body, and the anterior chamber (AC) in the eye has been suggested for a noninvasive blood glucose monitoring site. However, calculating blood glucose levels from measuring glucose levels in AC has been difficult and unclear. In this study, we aimed to examine glucose levels from AC and find a correlation with blood glucose levels. A total of 30 patients with cataracts (men and women, study 1; 7 and 3, study 2; 9 and 11) who visited Keio University Hospital from 2015 to 2018 and agreed to participate in this study were recruited. Glucose levels from AC and the blood were examined by a UV-hexokinase or H2O2-electrode method before/during the cataract surgery. These values were analyzed with regression analyses depending on the groups (blood glucose-ascending and descending groups). In the blood glucose-descending group, glucose levels from AC were strongly correlated with blood glucose levels (a high R2 value, 0.8636). However, the relatively moderate correlation was seen in the blood glucose-ascending group (a low R2 value, 0.5228). Taken together, we showed different correlation ratios on glucose levels between AC and the blood, based on blood glucose dynamics. Stacking data regarding this issue would enable establishing noninvasive blood glucose monitoring from measuring glucose levels in AC more correctly, which will be helpful for proper and prompt managements for glucose-mediated complications. [ABSTRACT FROM AUTHOR]

We report the results of a comprehensive 81Br NMR spectroscopic study of the structure and dynamics of two room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazolium bromide ([C4mim]Br) and 1-butyl-2,3-dimethylimidazolium bromide ([C4C1mim]Br), in both liquid and crystalline states. NMR parameters in the gas phase are also simulated for stable ion pairs using quantum chemical calculations. The combination of 81Br spin-lattice and spin-spin relaxation measurements in the motionally narrowed region of the stable liquid state provides information on the correlation time of the translational motion of the cation. 81Br quadrupolar coupling constants ( CQ) of the two RTILs were estimated to be 6.22 and 6.52 MHz in the crystalline state which were reduced by nearly 50% in the liquid state, although in the gas phase, the values are higher and span the range of 7-53 MHz depending on ion pair structure. The CQ can be correlated with the distance between the cation-anion pairs in all the three states. The 81Br CQ values of the bromide anion in the liquid state indicate the presence of some structural order in these RTILs, the degree of which decreases with increasing temperature. On the other hand, the ionicity of these RTILs is estimated from the combined knowledge of the isotropic chemical shift and the appropriate mean energy of the excited state. [C4C1mim]Br has higher ionicity than [C4mim]Br in the gas phase, while the situation is reverse for the liquid and the crystalline states. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Aim: To test the efficacy of heat- and steam-generating (HSG) sheets for the relief of symptoms of primary dysmenorrhea in young women. Materials & Methods: Thirty-four female university students were enrolled in this study. HSG sheets generate moist heat to keep the attached body area at 38.5 °C for 8 h. Subjects attached the HSG sheet to the lower abdominal or lumbar region for 5 to 8 h once a day on the first, second and third days of menstruation. Subjects documented symptoms of dysmenorrhea (abdominal pain, lumbago and lumbar dullness) on a self-recording form using a 4-score scale of 0 (mild) to 3 (severe) just before applying and after removing the HSG sheet. Either a small (54 cm [ABSTRACT FROM AUTHOR]