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When the lighting conditions are poor and the environmental light is weak, the image captured by the imaging device often has lower brightness and is accompanied by a lot of noise. The paper designs a progressive self‐calibration network model (PSCNet) for recovering high‐quality low‐light‐enhanced images. First, shallow features in low‐light images can be better focused and extracted with the help of attention mechanism. Next, the feature mapping is passed to the encoder and decoder modules, where the transformer and encoder‐decoder jump connection structures can be better combined with the semantic information of the context to learn rich deep feature information. Finally, the self‐calibration module can adaptively cascade the features decoded by the decoder and input them into the residual attention module quickly and accurately. Meanwhile, the LBP features of the image are also fused into the feature information of the residual attention module to enhance the detailed texture information of the image. Qualitative analysis and quantitative comparison of a large number of experimental results show that this method outperforms existing methods. [ABSTRACT FROM AUTHOR]

In locating a transformer partial discharge (PD) source, there is a large fluctuation error in the z‐coordinate of the location, which results with planar layout ultrahigh‐frequency (UHF) antenna sensors. For the large fluctuation error, this paper first theoretically analyzes the reason. According to the theoretical analysis results, a ladder‐wise calculation method of the PD source z‐coordinate is proposed: first, the x‐ and y‐coordinates of the PD source are calculated, then the univariate equation f(z) is derived, and the z‐coordinate of the PD source is obtained by f(z). Finally, the positioning effect of the ladder‐wise calculation method for PD source z‐coordinate is verified experimentally. Experimental results show that the proposed method can reduce the fluctuation of the z‐coordinate of the PD source from 0.6 to 0.2, and when the PD location sample set is ≥10, the average absolute error of the z‐coordinate is reduced from about 0.4 m to less than 0.1 m. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

This paper reports a novel oscillator circuit topology based on a transformer-coupled p-network. As a case study, the proposed oscillator topology has been designed and studied for 60 GHz applications in the frame of the emerging fifth generation wireless communications. The analytical expression of the oscillation frequency is derived and validated through circuit simulations. The root-locus analysis shows that oscillations occur only at that resonant frequency of the LC tank. Moreover, a closed-form expression for the quality factor (Q) of the LC tank is derived which shows the enhancement of the equivalent quality factor of the LC tank due to the transformer-coupling. Last, a phase noise analysis is reported and the analytical expressions of phase noise due to flicker and thermal noise sources are derived and validated by the results obtained through SpectreRF simulations in the Cadence design environment with a 28 nm CMOS process design kit commercially available. [ABSTRACT FROM AUTHOR]

SUMMARY In this paper, values of the electric field in the pressboard and oil during the polarity reversal test of the converter transformer were calculated with transient analysis. First, we confirmed the accuracy of the nonlinear analysis in the model test. Next, we carried out nonlinear transient electric field analysis for polarity reversal test of the converter transformer. In the results, when the applied time of dc voltage before the polarity reversal is 360 min, the values of the electric field of oil area are the same as when it is 90 min. Although, the electric field in the pressboard becomes higher in response to the applied time dc voltage, it does not cause a problem on the insulation. Because withstand voltage of pressboard is very high. In the results, the correlation between the applied time of dc voltage before the polarity reversal and the withstand voltage of transformer is considered low. This result can be applied to the design of the converter transformer. [ABSTRACT FROM AUTHOR]

This paper presents a 67GHz LC oscillator exploiting a three-spiral transformer and implemented in 65nm bulk complementary metal-oxide-semiconductor technology by STMicroelectronics. The three-spiral transformer allows operating with a lower voltage supply, still obtaining good phase noise performance, and achieving a compact design. Measured performances when supplied with 1.2 V are: oscillation frequency of 67 GHz, phase noise ( PN) equal to −96 dBc/Hz at 1 MHz frequency offset from the carrier, power consumption ( PC) equal to 19.2 mW and figure of merit ( FOM) equal to −179.7 dB/Hz. Measured performances when supplied with 0.6 V are: oscillation frequency of 67 GHz; PN equal to −88.7 dBc/Hz at a 1 MHz frequency offset from the carrier; PC equal to 3.6 mW and FOM equal to −179.7 dB/Hz. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A novel isolated high voltage-boosting converter, derived from the traditional forward converter, is presented in this paper. As compared with the traditional forward converter, the demagnetizing winding of the transformer in the proposed converter is used not only to demagnetize but also to improve the voltage conversion ratio. Therefore, the duty cycle is not limited, and the utilization of the transformer, also called coupled inductor, can be increased also. Furthermore, the proposed converter maintains the advantage of possessing a non-pulsating output current, leading to a small output voltage ripple. Moreover, by applying one additional voltage-boosting winding to the transformer, the voltage conversion ratio can be significantly improved. In addition, an active clamp circuit is employed in the proposed converter to reduce the voltage stress of the main switch, caused by the leakage inductance in the transformer, and the switches can achieve zero-voltage switching. Finally, the analysis of operating principles, choice of the turns, turns ratio, core size, and each wire size of the coupled inductor are described in detail, and the experimental results with a prototype with 12-V input voltage, 100-V output voltage, and 100-W output power are provided to verify the feasibility and effectiveness of the proposed converter. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]