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Accurate prediction of employment rate of graduated students can greatly help education authorities to make informed decisions as well as for universities to adjust their teaching plans. Unfortunately, prediction of the employment rate of graduated students is still a difficult problem because the historical employment rate data exhibits fluctuations. In this paper, a new method is proposed for employment rate prediction using fractional gray GM(1,1|$$ \mid $$sin) model, which aims to alleviate the effect of data fluctuation on prediction accuracy and increase the contribution of new data in the prediction procedure. To further decrease prediction error, a Fourier series is adopted to model the residual series. The proposed model, called Fourier Fractional GM(1,1|$$ \mid $$sin) Model (FFGMsin), is used to predict the employment rate of graduated students of Yanshan University from 2010 to 2019. Results show that the proposed method can obtain more accurate prediction results than GM(1,1) model and its variants. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [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 pseudo point-source model approximates the rupture process on faults with multiple point sources for simulating strong ground motions. A simulation with this point-source model is conducted by combining a simple source spectrum following the omega-square model with a path spectrum, an empirical site amplification factor, and phase characteristics. Realistic waveforms can be synthesized using the empirical site amplification factor and phase models even though the source model is simple. The Kumamoto earthquake occurred on April 16, 2016, with M 7.3. Many strong motions were recorded at stations around the source region. Some records were considered to be affected by the rupture directivity effect. This earthquake was suitable for investigating the applicability of the pseudo point-source model, the current version of which does not consider the rupture directivity effect. Three subevents (point sources) were located on the fault plane, and the parameters of the simulation were determined. The simulated results were compared with the observed records at K-NET and KiK-net stations. It was found that the synthetic Fourier spectra and velocity waveforms generally explained the characteristics of the observed records, except for underestimation in the low frequency range. Troughs in the observed Fourier spectra were also well reproduced by placing multiple subevents near the hypocenter. The underestimation is presumably due to the following two reasons. The first is that the pseudo point-source model targets subevents that generate strong ground motions and does not consider the shallow large slip. The second reason is that the current version of the pseudo point-source model does not consider the rupture directivity effect. Consequently, strong pulses were not reproduced enough at stations northeast of Subevent 3 such as KMM004, where the effect of rupture directivity was significant, while the amplitude was well reproduced at most of the other stations. This result indicates the necessity for improving the pseudo point-source model, by introducing azimuth-dependent corner frequency for example, so that it can incorporate the effect of rupture directivity. [ABSTRACT FROM AUTHOR]

There is much practical need in obtaining independent information about earthquake-source dynamic properties directly from observable data. One such dynamic parameter, the peak slip velocity during earthquake rupture, can be calculated from the comer frequencies of the source spectra, on the assumption of the validity of the ω²-source model. To obtain the source terms, observed Fourier spectra should be corrected for the site and path effects. Small-to-moderate earthquakes in Japan recorded on multiple rock sites are well suited for the application of this methodology. The results indicate that the maximum slip velocity of the selected earthquakes ranged from approximately 0.2 to 0.6 m/sec. Direct observation-based determinations of this type provide valuable physical information about the in-situ faulting processes that can be used for constraining dynamics theories of faulting or in ground-motion prediction. [ABSTRACT FROM AUTHOR]

Conventional calculation methods of air-core inductance utilized Neumann's equation for solenoidal coils and Fourier series for saddle coils. However, inductance formulas for arbitrarily shaped coils on a cylinder have not been well known. In this paper, mutual and self-inductances generated by any currents on a cylinder are expressed using Fourier-Bessel expansion of the vector potential. An experiment shows the validity of the proposed formulas. [ABSTRACT FROM AUTHOR]