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The IEEE Transactions on Automation Science and Engineering (T-ASE) wishes to thank the 1344 reviewers over the past year who have performed an essential role in maintaining the quality of this publication. T-ASE strives for the 90–90 standard, i.e., 90% of articles should be reviewed within 90 days of submission. The review process starts when the Editor-in-Chief assigns the paper to an Editor, who assigns it to an Associate Editor (AE). The AE then obtains confirmation from three to five reviewers, carefully studies the results, and makes a recommendation to the Editor, who then makes a decision that is reported back to the lead author. This review process is very demanding, especially under time constraints. We have summarized the process under “Guidelines for T-ASE Editors and AEs for Handling Papers” on our website. I am pleased to report that submissions have steadily increased (over 1000 in 2020) and our impact factor is now 5.083, a 2.94% increase over the past year. As we strive to increase the quality and impact of the journal, we rely on the hard work of our reviewers and members of the Editorial Board. To those dedicated volunteers, and to anyone who may have been inadvertently omitted from the following list, we extend our sincere appreciation. [ABSTRACT FROM AUTHOR]

A radio frequency (RF) capacitively coupled plasma was used to clean the nonplane large size first mirror (FM) used in the charge exchange recombination system (CXRS) of the Experimental Advanced Superconducting Tokamak (EAST). The mirror is made of 316L stainless steel (SS) and has a curved surface with a radius of 1600 mm and dimensions of 300 mm $\times80$ mm $\times40$ mm. Before cleaning, the FM was exposed to the plasma in 12 499 plasma discharges with a total plasma duration time of 86 036 s during three experimental campaigns from 2014 to 2016. An inhomogeneous deposition layer, consisting of carbon (C), oxygen (O), silicon (Si), tungsten (W), and molybdenum (Mo) with deposit particles sizes up to tens of micrometers was detected afterward. To recover the FM surface, argon (Ar) plasma cleaning was performed for 187.3 h in the laboratory. The inhomogeneous deposition was afterward not visible and uniformly removed. Scanning electron microscopy (SEM) and electron energy dispersion spectroscopy (EDS) results indicated that the micromorphology was developed during the cleaning, and few residual particles consisting of C and O also remained and covered about 5.3% of the cleaned mirror surface. The reflectivity of the FM was recovered from 15% to 68% at the wavelength of 532 nm, which was close to the initial preexposure value of 71.4%. A negligible difference of the recovered reflectivity along the FM surface was obtained which demonstrated the cleaning effectiveness and homogeneity of RF plasma cleaning for nonplane large mirrors. To prolong the FM lifetime, RF plasma could, therefore, be considered as one of the possible way for in situ cleaning. [ABSTRACT FROM AUTHOR]

Surface energy budget has great influence on earth surface biogeophysical and biogeochemical processes. As one of the components of surface energy budget, the longwave downward radiation (LWDR) is essential to many land applications. In this research, a new LWDR estimation scheme under clear sky by integrating MODIS thermal bands radiance and in situ measurements through the multivariate adaptive regression splines (MARS) has been proposed. The MODIS products and corresponding multinetwork in situ LWDR observations under clear skies in 2004 were extracted for model training and cross-validation. The in situ LWDR observations from seven SURFRAD sites in 2008 were used to test the new method. In training phase, the cross-validation RMSE, bias, and R-square of the new method are, respectively, 24.66 W/m2, −0.446 W/m2, and 0.88 in the daytime and 23.16 W/m2, −0.272 W/m2, and 0.92 in the nighttime. The test results at the seven SURFRAD sites show that the proposed method has good performance, with RMSE, bias, and R-square of 17.15 W/m2, 0.028 W/m2, and 0.91 in the daytime and 14.08 W/m2, −3.609 W/m2, and 0.94 in the nighttime, respectively. More importantly, the error analysis reveals that the predicted residual errors of the proposed method have a weak correlation with related meteorological parameters at global scale, which reflects the stability and robustness of the new method. [ABSTRACT FROM AUTHOR]

In this paper, a physically based numerical electromagnetic approach, by solving Maxwell's equations, is developed to investigate the scattering and the emission from double-layered media, where both the top and bottom interfaces are random sastrugi surfaces with a random horizontal shift between the two corresponding negative-slope facets of both interfaces. Numerical simulations are illustrated for bistatic scattering and four Stokes parameters at L-, C-, X-, and K-bands. Results indicate that the bistatic scattering and Stokes parameters are asymmetric for the double-sastrugi media, whereas for the other two structures, sastrugi surface alone and sastrugi surface with a planar bottom boundary, their scattering and the first two Stokes parameters are even symmetric relative to the azimuthal angle of 90°, and the third and fourth Stokes parameters are odd symmetric. In particular, the Stokes results no longer have the strong coherent fluctuations in angular variations shown in periodic double-layered structures because the random double-layered structure eliminates the coherent interference. It is interesting to observe that the internal total reflection may cancel if the coupled interactions between the two sastrugi interfaces are very strong, which results in decreasing scattering at the L-band, and its Stokes parameters are similar to those of the sastrugi alone. Numerical results also reveal that the maxima of cross-polarized specular scattering from double-sastrugi structures can be observed at cross incidence; however, they are at a deep dip for the latter two statistical symmetric structures. The sastrugi-sastrugi structure, being geometrically anisotropic, is capable of generating strong cross-polarized scattering and, subsequently, significant amounts of the third and fourth Stokes. The azimuthal patterns, at a viewing angle of 55°, of four Stokes parameters, although more complex, are feature rich where two striking extrema of third and fourth Stokes are presented. Compared with the L-band, the C-band presents strong azimuthal dependence of four Stokes. The simulation results offer deeper insights into the scattering and emission process in sastrugi surface and may lead to better retrieval of surface parameters from radar or radiometric measurements. [ABSTRACT FROM PUBLISHER]

A fundamental frequency-sorting algorithm with staircase modulation is proposed to balance the floating capacitors for modular multilevel converters. The driving pulses are assigned to the submodules at every fundamental period according to their charging capabilities for the capacitors. The charging capabilities of the driving pulses can be evaluated by sorting the voltage increments of the capacitors or derived from the symmetrical characteristic of the curve between the voltage increments and the pulse numbers. With this method, all the power devices switch only once per fundamental period, which is suitable for high-power applications. Meanwhile, the sorting frequency decreases to the fundamental frequency. Hence, a large number of calculation resources can be saved. Moreover, it does not need to measure the arm currents so that several current sensors can be saved and the communication protocol between the central and local controllers can be simplified. At last, a three-phase simulation platform with 20 submodules per arm and a down-scaled experimental prototype with eight submodules in each arm are built to validate the proposed voltage-balancing method. [ABSTRACT FROM PUBLISHER]

The publication offers a note of thanks and lists its reviewers. [ABSTRACT FROM AUTHOR]